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The limitations of

mammography include(A) 1015% false negative rate

(B) 10% false positive rate

(C) difficulty visualizing tumors in the tail of Spence

(D) all of the above

(E) none of the above

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Explanation:

There is a 1015% false negative rate of current mammography. In women4049 years old, nearly 25% of invasive breast cancers are not visualized.This drops to 10% for women 5059 years old. Almost 10% of patientswho have routine screening mammography are asked to return foradditional studies. This is to better clarify the abnormality. The additional

studies may include additional mammographic views or ultrasounds, or itmay require invasive studies such as a biopsy. Mammograms in general areless sensitive in younger women with dense breast tissue. Breast implantsmay also obscure a mammographic evaluation. Routine mammography hasa difficult time visualizing lesions deep against the chest wall, lateral in thetail of breast, or inferior in the inframammary fold.

BibliographyKopans D. Imaging analysis of breast lesions. In: Harris JR,

Lippman ME, Morrow M, et al. (eds.), Diseases of the Breast, 2nd ed.Philadelphia, PA: Lippincott, Williams & Wilkins, 2000, 128134.

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Phyllodes tumors

(A) present in postmenopausal women

(B) are often malignant(C) require mastectomy because of their high recurrencerate

(D) tend to recur

(E) are responsive to hormonal manipulation

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Explanation : Phyllodes tumors, also known as cystosarcoma phyllodes, are stromal tumors. They are well

circumscribed and do not have a true capsule. The cut surface of one of these tumors tends to bemucoid. There are numerous small projections that make surgical enucleation difficult.

Phyllodes tend to occur in an older population than fibroadenomas (FAs). FAs are also stromaltumors, and it is thought that phyllodes may arise from these benign tumors. Phyllodes tend tooccur in the fourth decade of life. Most of these tumors present as painless masses that are

round and smooth. On mammogram and ultrasound they are similar in appearance to FAssmooth, solid, multilobulated margins. There may also be fluid within the mass on ultrasound,

suggesting phyllodes over FA. Seventy-five percent of phyllodes tumors are benign. Similar to other stromal tumors, malignancy

is difficult to establish and is based on histologic appearance. Stromal overgrowth is nowconsidered the most important predictor of aggressive behavior. Other characteristics that areconsidered are cellular atypia, mitotic activity, and tumor margins.

Phyllodes tend to recur regardless of benign or malignant status. The reported incidence is 2025% of recurrence. Current recommendations for initial surgical treatment of theses tumors are

wide local excision with a 2

3 cm margin. This can usually be done without requiring amastectomy and is based on tumor to breast mass ratio. Usually if the tumor recurs, a totalmastectomy is required; however, some women may be able to tolerate a reexcision without poorcosmesis. Less than 5% of all phyllodes tumors metastasize. Regional lymph node metastasis israre and an axillary dissection is not warranted. Radiation therapy is also not indicated becausethis is not a multifocal disease like ductal breast cancer. The tumors are only weaklyradiosensitive; however, radiation therapy may offer some palliation for recurrent disease.Hormonal manipulation is not beneficial for these patients. This is felt to represent the mixedepithelial (positive receptors) and stromal (no receptors) components.

BibliographyDonegan W. Sarcomas of the breast. In: Donegan W, Sprattt J (eds.), Cancer of the

Breast, 5th ed. St. Louis, MO: W.B. Saunders, 2002, 918923.

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The most common etiology ofsenescent gynecomastia is

(A) cirrhosis

(B) testicular tumor

(C) renal disease

(D) idiopathic causes

(E) drug induced

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Explanation

: Gynecomastia is the benign proliferation of breast glandular tissuein males. This tends to occur in infancy, at puberty, and in old age.

Gynecomastia results from an imbalance of the normal hormonalmilieu or a change in breast tissue sensitivity to estrogen. The

testes secrete 95% of the total body testosterone and only 15% ofthe circulating estradiol. The vast majority of circulating estradiol isfrom the peripheral conversion of testosterone and adrenal steroidsvia the aromatase enzyme. Most of the hormones are bound to sex-hormone binding globulin (SHBG), a protein formed in the liver.SHBG has a higher affinity for androgens than estrogen. Animbalance in any of these pathways may results in an increase offree estrogen as compared to bound estrogen (Fig. 15-5).

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Tamoxifen

(A) is an estrogen receptor (ER) agonist

(B) is an ER antagonist

(C) has been shown to decrease the incidence ofrecurrent breast cancer by 47%

(D) has been shown to decrease the risk of future breast

cancer by 49% in high-risk patients

(E) all of the above

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Explanation

: Tamoxifen, a selective estrogen receptor (ER) agonist antagonist, firstcame into the market in the 1970s. It is a well-studied drug. The antagonisteffects of tamoxifen are related to its competitive binding of the estrogenreceptor, especially in breast tissue. This results in a reduced transcriptionof estrogen related proteins and effective blockade of cell cycle in G1. This

in turn then translates to ineffective tumor growth. Tamoxifen has apparent estrogen agonist effects on the endometrial lining,

as shown by the increase in endometrial cancer found in women beingtreated with the drug. This risk is about 1%. The cancers are usually foundin stage I and are very treatable. In addition, there is an increased risk ofvenous embolic phenomena that is related to the estrogen agonist effects.Tamoxifen also increases bone density and improves lipid profilesboth

related to ER agonist activity. The major side effects that women complainabout while taking tamoxifen are hot flashes and sleep disturbancessimilar to menopausal symptoms attributed to decreased estrogen.

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Explanation

: Mastalgia, or breast pain, is a commoncomplaint and a common reason for referral to a

breast center. Evaluation of breast pain shouldinclude a thorough history and examination.With a good history, you can begin to categorizethe pain. Typical types of mastalgia can be

described as cyclical pronounced, noncyclical,trauma, musculoskeletal/chest wall, andmiscellaneous uncommon cause.

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Cyclical pronounced pain is the most common. Itis related to the menstrual cycle, especially

ovulation. The average age is 34 years. Patientscomplain of "heaviness" and "tenderness."Nodularity is common, especially in the upperouter quadrants. This also tends to fluctuate

with the menstrual cycle. The pain is often in theupper outer quadrant, may be bilateral, and canradiate down the arm.

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Noncyclical mastalgia is not related to themenstrual cycle. The average age of the

patient is again 34 years old. The pain isdifferent from cyclical pain in that is morelocalized and described as a "burning" or

"pulling." Nodularity is typically lesspronounced, but it is present in greaterthan 50% of the patients.

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A 40-year-old woman presents with a 2 cm mass in her right breast

first detected bymammography (Fig. 15-2). Radiographic core biopsy ofthe lesion is selected for diagnosis and reveals infiltrating ductal carcinoma.

She has no palpable axillary lymph nodes, core bx: invasive malignant,

SLNB:POSITIVE

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AJCC) TNM staging system is

(A) I

(B) II

(C) III

(D) IV

(E) V

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The AJCC TNM Clinical Staging

System is as follows :

1. Primary tumor (T)

Tx: primary tumor cannot be assessed

T0: no primary tumor Tis: carcinoma in situ

T1: tumor 2 cm.

T2: tumor > 2 cm. but 5 cm.

T3: tumor > 5 cm. T4: tumor with extension to chest wall, skin edema or

ulceration or inflammatory carcinoma

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Regional lymph nodes (N)

. Nx: regional lymph nodes cannot be assessed

N0: no regional lymph node metastasis

N1: metastases to mobile axillary lymph nodes N2: metastases to fixed, matted or clinically

apparent axillary lymph nodes or internalmammary nodes

N3: metastases to axillary and infraclavicularlymph nodes, clinically apparent internalmammary nodes or supraclavicular lymph nodes

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Distant metastasis

Mx: distant metastasis cannot be

assessed M0: no distant metastasis

M1: distant metastasis

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Stage grouping

.

Stage 0: TisN0M0

Stage 1: T1N0M0

Stage 2A: T0N1M0, T1N1M0, T2N0M0 Stage 2B: T2N1M0, T3N0M0

Stage 3A: T0N2M0, T1N2M0, T2N2M0, T3N1M0,T3N2M0

Stage 3B: T4N0M0, T4N1M0, T4N2M0 Stage 3C: AnyTN3M0

Stage 4: AnyT AnyN M1

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Which of the following is false regardinglobular carcinoma in situ?

(A) It is a marker for increased risk of breast cancer.

(B) Mirror image breast biopsy is indicated.

(C) Subsequent invasive cancer is more often ductal in origin.

(D) Treatment is close observation versus bilateral prophylacticmastectomy.

(E) Prognosis is solely related to the development of subsequent

cancer.

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Explanation:

The histologic picture consists of many clusters of epithelial cells formingislands of neoplastic cells but maintaining a lobular architecture. It occursmore often in premenopausal women and does not form a palpable mass.It is most commonly found as an incidental finding on biopsy, as it does nothave any mammographic findings.

Lobular carcinoma in situcarries a risk of developing into an invasive ductalcarcinoma in 1035% of patients over a period of 1520 years.

Because the risk of subsequent breast cancer is almost the same for bothbreasts, mirror image biopsies of the opposite breast are not indicated.

Histologic examinations are generally favorable and deaths are unusual inwomen with appropriate medical care. Any treatment of in situcarcinoma isaimed at preventing invasive disease.

Treatment options include close observation or pharmacologic prophylaxis.A 5-year course of tamoxifen has been shown to reduce the relative risk ofinvasive cancer by 56% in women with LCIS. Surgical options such asbilateral mastectomy or breast-conserving surgery are considered only inspecial circumstances in which the patient may have multiple risk factors

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The effective osmotic pressure between the plasmaand interstitial fluid compartments is primarily

controlled by

(A) Bicarbonate

(B) Chloride ion

(C) Potassium ion

(D) Protein

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Explanation

: The dissolved protein in plasma does notpass through the semipermeable cell

membrane, and this fact is responsible forthe effective or colloid osmotic pressure.(See Schwartz 7th ed.)

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The simplest effective method of estimating thedegree of acidosis in a patient in shock is the

measurement of

(A) Arterial pH

(B) End tidal CO2 concentration

(C) pH of mixed venous blood

(D) Serum CO2 level

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Explanation:

Only the measurement of arterial pH andPCO2 gives an accurate picture of the

degree of acid-base imbalances. (SeeSchwartz 7th ed.)

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Explanation:

Syncope is not associated with a hemolytictransfusion reaction, whereas the other

listed symptoms are common occurrences.(See Schwartz 7th ed.)

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After drainage of a pelvic abscess, a 45-year-old patientreceiving 70% oxygen is found to have the following arterial

blood gases: pH, 7.48; PO2, 55 mm Hg; PCO2, 30 mm Hg.

These results are most consistent with the diagnosis of

(A) Chronic obstructive pulmonary disease

(B) Postoperative pain and anxiety

(C) Adult respiratory distress syndrome

(D) Postoperative atelectasis

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Explanation:

The combination of hypoxemia that is resistant to highoxygen concentrations and hyperventilation ischaracteristic of the adult respiratory distress syndrome(ARDS). There are four general causes of hypoxemia:hypoventilation, a low ventilation-perfusion ratio,diffusion abnormalities, and pulmonary shunting.Although the first three conditions improve in responseto an increased inspired oxygen concentration most ofthe hypoxemia seen in ARDS is secondary to shunting

and so is not ameliorated by oxygen. The abnormalitiesseen in ARDS are thought to result from injury to thealveolar-capillary membrane that causes an increasedpermeability of the membrane, which in turn leads tointerstitial pulmonary edema and decreased pulmonarycompliance. (See Schwartz 7th ed.)

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All of the following result from the placement of an intraaorticballoon pump in a patient with acute myocardial failure

EXCEPT

(A) Diastolic blood pressure elevation

(B) Increased cardiac output

(C) Increased pulmonary perfusion

(D) Increased probability of survival

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The P50 value (the PO2 at which 50% of hemoglobin is saturatedwith oxygen) indicates the position of the oxyhemoglobin

dissociation curve along the horizontal axis. All of the followingconditions can produce a leftward-shifted curve (decreased P50)

EXCEPT

(A) Carbon monoxide poisoning

(B) Hypothermia

(C) Acidosis

(D) 2,3-diphosphoglycerate deficiency

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Explanation:

Determinations of P50 are used to monitor the affinity of oxygen forhemoglobin, with the normal value being approximately 26 mm Hg.A low P50, indicating an increased affinity of oxygen for hemoglobinand a decreased release of oxygen to the tissues, causes a leftwardshift in the oxyhemoglobin dissociation curve. Low red blood celllevels of 2,3-diphosphoglycerate (which occur when blood is storedmore than 2 weeks), carbon monoxide poisoning, and hypothermialower the P50. Conversely, the natural affinity of hemoglobin foroxygen is decreased by high levels of diphosphoglycerate, by carbondioxide (Bohr effect), by heat, and by hydrogen ions. In acidosis,shifting of the oxyhemoglobin dissociation curve to the right

(increased P50) reflects a protective mechanism to improve oxygensupply to the tissues. However, in spite of elevations of the P50,severe arterial desaturation (e.g., pulmonary shunting) may offsetany potential gains in oxygen availability. (See Schwartz 7th ed.)

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The earliest manifestations of serious gram-negative infectionmay consist of a triad of signs that includes

(A) Tachypnea, hypotension, and an alteredsensorium

(B) Tachypnea, hypotension, and lactic acidosis

(C) Thrombocytopenia, hypotension, and lacticacidosis

(D) Mild hyperventilation, respiratory alkalosis,and an altered sensorium

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Explanation:

The development of mild hyperventilation, respiratoryalkalosis, and an altered sensorium may be the earliestsign of gram-negative infection. This triad may precede

the usual signs and symptoms of sepsis by several hoursto several days. Although the exact pathophysiology ofthis manifestation is unknown, the triad of signs isthought to represent a primary response to bacteremia.Early recognition of the findings, followed by a prompt

search for the source of infection, may allow diagnosisand treatment prior to the onset of shock. (See Schwartz7th ed.)

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Cardiac preload is determinedby

(A) End-diastolic volume

(B) End-diastolic pressure

(C) End-systolic volume

(D) End-systolic pressure

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Explanation:

Starling's law of the heart states that the force of musclecontraction depends on the initial length of the cardiac fibers. Usingterminology that derives from early experiments using isolatedcardiac muscle preparations, preload is the stretch of ventricularmyocardial tissue just prior to the next contraction. Preload isdetermined by end-diastolic volume (EDV). For the right ventricle,central venous pressure (CVP) approximates right ventricular end-diastolic pressure (EDP). For the left ventricle, pulmonary arteryocclusion pressure (PAOP), which is measured by transientlyinflating a balloon at the end of a pressure monitoring catheterpositioned in a small branch of the pulmonary artery, approximates

left ventricular end-diastolic pressure. The presence ofatrioventricular valvular stenosis will alter this relationship. (SeeSchwartz 8th ed., Chapter 12, Cardiac Output and RelatedParameters

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Positive end-expiratorypressure (PEEP) ventilation is widelyused in the treatment of acute pulmonary failure. The

beneficial effects of PEEP include all of the following EXCEPT

(A) Decreased pulmonary shunting

(B) Decreased extravascular lung water

(C) Increased resting volume of the lung

(D) Increased oxygenation

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Explanation:

The mechanism of action of PEEP ventilation has notbeen completely elucidated. However, the beneficialeffects of PEEP include (1) an increase in oxygenation

(PaO2); (2) an increase in resting volume (i.e.,functional residual capacity, of the lung); (3) an increasein pulmonary compliance; (4) an increase in the ratio ofventilation to perfusion when the ratio is initially low;and (5) decreased pulmonary shunting (venous

admixture). There has been no good experimentalevidence that PEEP leads to a direct decrease in lungwater. (See Schwartz 7th ed.)

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All of the following findings would indicate that a patientrequires mechanical ventilatory support EXCEPT

(A) Respiratory rate greater than 30 breaths perminute

(B) Vital capacity less than 15 mL/kg

(C) Maximal inspiratory force of 40 cm H2O

(D) Alveolar-arterial oxygen gradient greaterthan 350 torr

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Explanation:

The treatment of acute respiratory insufficiency is based primarilyon ventilatory support. Endotracheal intubation, preferably throughthe nose, is considered the technique of choice. A maximalinspiratory force of 40 cm H2O is nota criterion for ventilatorysupport. On the other hand, a patient who has stable vital signs andwho (1) exhibits adequate oxygenation on an inspired oxygenconcentration of 0.4 or less, (2) has a resting minute ventilation lessthan 10 L/min, (3) has a vital capacity greater than 15 mL/kg, and(4) has a tidal volume greater than 5 mL/kg almost certainly willtolerate withdrawal of ventilatory support. A maximal inspiratoryforce of 30 cm H2O or less (i.e., more negative), however,

generally is necessary to maintain spontaneous ventilation.Consideration of all of these parameters together would greatlyassist in a decision whether or not to withdraw mechanicalventilation. (See Schwartz 7th ed.)

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Which of the following statements about organellefunction is incorrect?

(A) The rough endoplasmic reticulum (rER) is the site of protein synthesis and thecotranslational modification of proteins.

(B) The smooth endoplasmic reticulum (sER) is the site of phospholipid synthesis,steroid hormone synthesis, drug detoxification, and calcium store release.

(C) The Golgi complex is the site of vesicular packaging of proteins, membranecomponent recycling, and posttranslational modification of proteins.

(D) The mitochondrion functions in acetyl-CoA production, tricarboxylic acid (TCA)cycle, oxidative phosphorylation, and fatty acid oxidation.

(E) The lysosome contains amino acid oxidase, urate oxidase, catalase, and other

oxidative enzymes relating to the production and degradation of hydrogen peroxideand oxidation of fatty acids.

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Explanation : Lysosomes contain acid hydrolases or lysosomal enzymes that include proteases, nucleases,

lipases, and galactosidases that function at an acidic pH to degrade old intracellular organelles orphagocytosed substances. Organelles have a relatively rapid rate of turnover (e.g., livermitochondria have a lifetime of 10 days) and are broken down in a process called autophagy. Old ordamaged organelles are enveloped by an additional membrane to create an autophagosome, whichfuses with a lysosome for degradation. For phagocytosed or endocytosed substances, these aretaken-up into early endosomes where some of the materials are recycled back to the plasmamembrane and others continue as late endosomes. Golgi hydrolase vesicles containing inactive

lysosomal enzymes fuse with late endosomes to form mature lysosomes. The late endosomescontain proton pumps to produce a pH 5 environment to activate the lysosomal enzymes from theGolgi hydrolase vesicles. Although most lysosomes function in intracellular digestion, a few celltypes such as neutrophils and osteoclasts are able to release lysosomal contents extracellularly fordegrading materials. There are numerous lysosomal storage diseases (e.g., Hunter's, Hurler's,Sanfilippo A, Tay-Sachs, Gaucher's, Niemann-Pick, Pompe's, I-cell, and Krabbe's disease) eachassociated with mutations of different lysosomal enzymes and abnormal accumulation of undigestedmaterials.

Peroxisomes are unique organelles in that they are surrounding only by a single membrane andcontain amino acid hydrolase, hydroxyacid oxidase, urate oxidase, and catalase for the productionand breakdown of hydrogen peroxide. The oxidative reactions performed by peroxisomes are

important for the breakdown of toxic substances and fatty acid molecules. Peroxisomes are alsoessential for the production of certain phospholipid classes in myelin; therefore many peroxisomaldisorders result in neurologic disease. Although peroxisomes are self-replicating organelles, they donot contain their own DNA or ribosomes and must import their proteins from the cytosol, which aremarked by a 3-amino acid signal sequence. The peroxisomal import process involves dockingproteins, peroxins, and ATP hydrolysis. Peroxisomal dysfunction is the etiology of Zellweger'ssyndrome (aka cerebrohepatorenal syndrome), which is an autosomal recessive neonatal syndromecharacterized by incomplete myelinization of nervous tissue and muscular hypotonia, hepatomegaly,and small glomerular cysts of the kidney resulting in death shortly after birth.Adrenoleukodystrophy (ALD) is an X-linked recessive disorder involving the absence or dysfunctionof peroxisomal enzymes essential for fatty acid -oxidation. ALD results in the myelin degeneration

in the nervous system and abnormal intracellular accumulation of lipids, manifesting in progressivedementia, spastic paralysis, and adrenal insufficiency in children (see Figs. 1-12and 1-13).

A 41 ld f l t t th d t t ft

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A 41-year-old female presents to the emergency department aftersustaining a gunshot wound to the abdomen, with injuries to the liver

and large bowel. Despite successful resuscitation and operativeintervention, the patient dies 2 weeks later of multisystem organ

failure in the intensive care unit. Which organ most likely first

experienced dysfunction?

(A) liver

(B) gastrointestinal tract

(C) lung

(D) kidney

(E) heart

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Explanation:

Death due to trauma with hemorrhagic shock is arranged in a trimodal distribution: immediate (at the scene),within the first 24 hours, and 1 week or more following the injury. In the acute period after trauma, mortality isattributable to massive hemorrhage or neurologic injury. Direct injury to an organ contributes to a primarymultiple organ dysfunction in this early period. In contrast, late deaths, occurring at least 1 week subsequent tothe trauma, generally arise from secondary multiple organ dysfunction syndrome (MODS). This conditiondevelops in 3060% of these trauma patients and is associated with an 80% mortality rate.

MODS is defined as the failure of multiple organs in a critically ill patient in whom the maintenance ofhomeostasis requires intervention. This syndrome appears as the end point in a variety of conditions, not isolated

to trauma and hemorrhagic shock. In the case of trauma, the prevalence of MODS is ascribed to a two-hitphenomenon, first proposed by Partrick et al. This hypothesis suggests that trauma represents an initial insultwhich predisposes the immune system to react later to a lesser injury with a massive response, mediatedprimarily by neutrophils, resulting in great collateral damage (Fig. 6-12). The primed neutrophils mediate furthertissue injury by means of proteolytic enzymes, reactive oxygen species, and vasoactive substances. A study fromFan et al. (1998) demonstrated that, in a model of murine hemorrhagic shock, intratrachial administration of LPS1 hour after successful resuscitation provoked enhanced neutrophil sequestration and edema in the lung; thisresponse was not generated in the absence of resuscitated hemorrhagic shock or LPS. Following traumatichemorrhagic shock, the patient is resuscitated into not only a local but also a systemic inflammatory responsesyndrome (SIRS), with generalized inflammation generated within 1 hour of injury. Neutrophils and monocytesare first activated, releasing inflammatory mediators. TNF- , IL-1, and IL-6 are particularly implicated in the

evolution of MODS, found in studies to induce this syndrome and to be present in elevated levels. Additionally,the coagulation and alternative complement cascades are initiated. In the absence of further injury, SIRS isbeneficial to recovery from the trauma. The second, often trivial, insult, however, results in an enhanced immuneresponse from the already primed immune cells, notably neutrophils. This second hit may arise from a mildinfection, pulmonary aspiration, or blood transfusion (Table 6-2). Bacterial translocation from the ischemicmucosa of the gastrointestinal tract is a focus of investigation as a potential source of contamination. Ultimately,organs not involved in the original trauma experience an alteration in function. Usually, the lung is affected priorto the kidneys, liver, and gastrointestinal tract. Offiner and Moore (2000) attribute this predilection to direct lunginjury, to the lung's filtration of toxins and cytokines as well as to its sensitivity for developing vascularpermeability

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Risk Factors Associated with the Development of Multiple Organ Dysfunction

Following Trauma

1.Associated with the first insult Severity of tissue injury Shock-ischemia/reperfusion

Severity of the systemic inflammatory response 2.Associated with the second insult Infection Transfusion Secondary operative procedures 3.Host factors Age Preexisting conditions

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A 42 ld l h d l l I f b i

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A 42-year-old male presents to the emergency department as a level I trauma after beinginvolved in a motor vehicle accident. On initial examination, the patient has a GCS of 7(localizes to pain, no eye opening, and no verbal response). The patient has multiple

injuries including a long bone fracture. The patient's vital signs are stable. You consultorthopedic surgery, and they want to take the patient to the operating room (OR) torepair his fracture. A CT scan of the head shows mild-to-moderate diffuse cerebral

edema. What is the most appropriate course of action to take with this patient?

A) Allow the patient to go the OR immediately for repairof his fracture.

(B) Consult neurosurgery to evaluate for placement ofan ICP monitor prior to his going to the OR.

(C) Consult neurosurgery to evaluate for placement ofan ICP monitor after he returns from the OR.

(D) Delay surgery indefinitely until the patient'sneurologic status improves

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Explanation:Although there is much debate regarding the precise indications for and benefit of ICP monitoring, several recent studies have suggested thatan aggressive stance toward monitoring head-injured patients is associated with a reduced risk of mortality. In2000, the American Association of Neurological Surgeons Joint Section on Neurotrauma and Critical Care inassociation with the Brain Trauma Foundation published guidelines relating to the indications for ICP monitoring.In this review, it was noted that ICP monitoring helps in the early detection of intracranial mass lesions, limits theindiscriminate use of therapies to control ICP that may be potentially harmful, helps in determining prognosis,and may improve outcome. Therefore, the Brain Trauma Foundation guidelines state that a comatose head-injured patient (GCS 38) with an abnormal CT scan should undergo ICP monitoring. Additionally, comatose

head-injured patients with normal CT scans should undergo ICP monitoring if they have two or more of thefollowing features at admission: age over 40, unilateral or bilateral motor posturing, or a SBP of less than 90mmHg. A review of the Ontario Trauma Registry from 1989 to 1995 was completed to test the hypothesis thatinsertion of ICP monitors in patients with traumatic brain injuries is not associated with a decrease in the deathrate. The conclusions were that monitor insertion rates varied widely from hospital to hospital and that, aftercontrolling for injury scale and injury mechanism, insertion of an ICP monitor was associated with statisticallysignificant decrease in the death rate among patients with severe traumatic brain injury. Finally, a retrospectivereview of data for consecutive patients with severe closed head injury (GCS 8) and long bone fracture admittedover an 8-month period in 34 academic trauma centers in the United States was completed. The purpose of thisstudy was to examine variations in the care of patients with severe head injury, to determine the proportion ofpatients who received care according to the Brain Trauma Foundation guidelines, and to correlate the outcome

from severe traumatic brain injury with the care received. The results revealed, in addition to considerablevariation in the rates of ICP monitoring, that management at an aggressive center (defined as those placing ICPmonitors in >50% of patients meeting the Brain Trauma Foundation criteria) was associated with a significantreduction in the risk of mortality. Another consideration regarding the patient in the above question is theanticipated use of intravenous fluids in the operating room under the situation of general anesthesia in which theneurologic examination is compromised. Worsening cerebral edema and secondary neurologic injury mayprogress unnoticed without the ability to monitor ICP and CPP. With all of these factors in mind, the mostappropriate course of action is to consult neurosurgery to evaluate the patient for placement of an ICP monitorprior to his going to the operating room.

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Indications for operating on gunshot wounds to the spineinclude all of the following except:

(A) persistent CSF leak

(B) neurologic deterioration

(C) compression of a nerve root

(D) operate on all cases

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Explanation

: Most penetrating wounds of the spine in the United States of America today are caused bygunshot wounds. These are more common in urban areas where the rates of violent crimes arerelatively high. Civilian gunshot wounds cause direct injury to the spinal cord by the bullet,whereas high velocity military weapons tend to cause more indirect damage from cavitation andshock waves. Although debated, surgery has been shown to have little effect on recovery forpatients with spinal cord injury secondary to gunshot wounds to the spine. For this reason, thetrend seems to be now to treat patients with gunshot wounds to the spine without surgery unless

they have a specific indication to do so. One of the historically cited reasons for operating on allgunshot wounds to the spine was to prevent infection. This may likely remain pertinent withmilitary gunshot wounds since these cause massive tissue injury. With the creation of newantibiotics, however, infections may be prevented in civilian gunshot wounds with adequatecourses of antibiotics alone.

The more commonly accepted indications for operating on gunshot wounds to the spine includeneurologic deterioration, compression of a nerve root, and persistent cerebrospinalfluid leak orfistula.In addition, there are a few late complications which may develop thatrequire surgical treatment. First, an abscess could develop that requires surgical drainage,

especially if there is compression of the spinal cord. Second, a syrinx may develop and be thecause of late neurologic deterioration. This could require a shunting procedure to alleviate thesymptoms. Third, lead intoxication may result if the bullet is lodged in a disc space or jointcapsule. The treatment for this would include removing the bullet fragment and administering achelating agent. Finally, spinal deafferentation following spinal cord injury may result inintractable dysesthetic pain. Placement of a dorsal column stimulator or dorsal root entry zonelesioning may help in these cases.

A 19 ld it t t th d t t ith 24 h

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A 19-year-old army recruit presents to the emergency department with a 24-hhistory of right lower quadrant pain, fever to 100.5F, anorexia, and two loose

stools. He was taken to surgery for the presumptive diagnosis of appendicitis;however, the appendix looked completely normal while the terminal ileum

was quite inflamed. What procedure should be performed?

(A) appendectomy

(B) ileocecectomy with ileostomy

(C) full abdominal exploration to evaluate forfurther obvious lesions and colonoscopy prior todischarge

(D) None. The patient should be closed andrequest immediate medical discharge from thearmy as he now must battle CD

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Explanation:

This patient has acute ileitis. This may or may not be related to Crohn's (and most often is notrelated to CD). The correct procedure in this case is appendectomy only. Although the appendixappears normal on direct examination, the right lower quadrant wound or the laparoscopicwounds that the patient already has would be confusing in the future. There is no indication foran ileocecectomy as this is an infectious process and will heal with antibiotics. If this is in fact aninitial presentation of CD, additional therapy will be required but will heal without surgery.

Acute ileitis presents with right lower quadrant pain, fever, and anorexia much the same as acuteappendicitis. It is often caused by Campylobacteror Yersiniaspecies. These can be cultured fromthe appendix and from the patient's stool. In one study of patients with signs and symptoms ofacute appendicitis, nine patients had only thickened terminal ileum on ultrasound. Five of theseproceeded to surgery in spite of these results. All nine had positive cultures of C. jejuni, and allrecovered easily with no progression to CD. There were no adverse events from theappendectomies. Similarly, a study of 138 normal appendices excised for presumed appendicitisyielded positive cultures for C. jejuniand Y. enterocolitoca. At the time of surgery, the appendixappeared normal, but 62% of these culture positive patients had terminal ileitis or mesentericadenitis. There were no pathologic cultures of C. jejunior Y. enterocolitocaisolated from 326

normal appendices excised during gynecologic surgeries. Although acute terminal ileitis canpresent as appendicitis and appear to be early Crohn's, the majority are of infectious etiologies. BibliographyEvers BM. Small bowel. In: Townsend CM, Beauchamp RD, Evers BM, et al. (eds.),

Sabiston Textbook of Surgery, 16th ed. Philadelphia, PA: W.B. Saunders, 2001, 893.

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Intraabdominal adhesions following abdominal surgery have been associatedwith all of the following except:

(A) small bowel obstruction

(B) infertility

(C) chronic pelvic pain

(D) intestinal malabsorption

(E) increased risk for enterotomy on subsequentlaparotomy

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Explanation:

Following laparotomy, up to 95% of patients will develop adhesions. Although the majority ofpatients will not develop any clinical consequences fromadhesion formation, there are significantmorbidities associated with their development. In a retrospective study using the ScottishNational Health Service database, 5.7% of all readmissions following abdominal or pelvic surgeryover 10 years were found to be related to adhesions. Mid- and hind-gut procedures had thehighest number of adhesion-related readmissions, and most admissions occurred in the first yearafter surgery.

Intraabdominal adhesions are the leading cause for small bowel obstruction in the industrializedworld. Up to 80% of admissions for small bowel obstruction are secondary to postoperativeadhesions. Types of procedures most commonly associated with adhesions-related small bowelobstruction are gynecologic operations, appendectomy, and small bowel operations. Overall,patients who undergo any abdominal procedure have a 5% incidence of developing adhesion-related intestinal obstruction. Obstruction may occur at any time following laparotomy; however,in 1729% of patients who develop postoperative obstruction, it occurs within the first monthafter surgery. In terms of location, obstructions from adhesions tend to occur at the level of theileum, possibly because of its greater mobility within the abdomen.

Intraabdominal adhesions account for up to 20% of secondary infertility in women.Adhesions in the pelvis can cause infertility by blocking the fallopian tubes or interfering in ovumtransfer from the ovary to the tubes. The risk of infertility is probably related to the degree ofperitoneal trauma and severity of the ensuing adhesions. In a retrospective study of women withtubal infertility, a history of appendectomy with appendiceal rupture significantly increased therisk of infertility while the history of simple appendectomy without rupture did not. It is alsobelieved that pelvic and abdominal adhesions can cause chronic pain. Theoretically, adhesionsmay cause pain by putting tension on the sensitive parietal peritoneum. Histologic study has alsoshown the presence of sensory nerve fibers within abdominal adhesions. Pain symptoms and

degree of adhesions do not correlate well; however, most studies in the gynecologic literatureshow at least short-term improvement in pain following laparoscopic lysis of adhesions.

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Which of the following is notan indication for surgicalintervention in ulcerative colitis?

(A) intractable bloody diarrhea

(B) perforation

(C) toxic colitis

(D) diagnosis of ulcerative colitis for more than 5 years

(E) poorly controlled extraintestinal manifestations

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Explanation:

Indications for surgical intervention in ulcerativecolitis include intractable symptoms, perforation,toxic colitis, increasing cancer risk, hemorrhage,

fulminating disease, and poorly controlledextraintestinal manifestations. The cancer riskafter initial diagnosis is approximately 57%during the first 57 years, but increases to 40%at 20 years postdiagnosis. Therefore, surgical

intervention is commonly recommendedbeginning approximately 10 years after initialdiagnosis.

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All of the following are associated with an increased risk ofperforation in acute colonic pseudoobstruction (Ogilvie's

syndrome) except:

(A) older age

(B) increasing cecal diameter

(C) delay in decompression

(D) diabetes mellitus

(E) chronic ischemia

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Explanation:

Acute colonic pseudoobstruction is a syndrome of massive dilationof the colon without mechanical obstruction that develops inhospitalized patients with serious underlying medical and surgicalconditions. Increasing age, cecal diameter, delay in decompression,and status of the bowel significantly influence mortality, which is

approximately 40% when ischemia or perforation is present.Evaluation of the markedly distended colon in the intensive care unitsetting involves excluding mechanical obstruction and other causesof toxic megacolon such as Clostridium difficileinfection, andassessing for signs of ischemia and perforation. The risk of colonicperforation in acute colonic pseudoobstruction increases when cecal

diameter exceeds 12 cm and when the distention has been presentfor greater than 6 days. Appropriate management includessupportive therapy and selective use of neostigmine andcolonoscopy for decompression. Early recognition and managementare critical in minimizing complications.

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Which of the statements regarding cecal volvulus isnottrue?

(A) Cecal volvulus accounts for 10% of cases of colonic volvulus.

(B) Cecal vovulus is thought to have a congenital etiology related toincomplete peritoneal fixation of the right colon.

(C) Radiographic evidence of a cecal volvulus includes a large,dilated loop of colon with the loop of colon pointing to the left upperquadrant of the abdomen.

(D) Definitive treatment for cecal volvulus includes a right

hemicolectomy.

(E) Reduction of the cecal volvulus with fixation of the cecum to theabdominal wall provides a similar outcome to segmental resection.

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Explanation:

While sigmoid volvulus accounts for >80% of colonic volvulus cases,cecal volvulus is relatively rare, accounting for 10% of cases.Sigmoid volvulus is felt to be "acquired" through accumulation ofrisk factors while cecal volvulus is considered "congenital" becauseof individual anatomic variation. Both sigmoid and cecal volvulus

demonstrate a large, dilated loop of colon on plain radiograph. Theloop "points" to the left upper quadrant of the abdomen with a cecalvolvulus and to the right upper quadrant with a sigmoid volvulus.While cecopexy has been well described and does have somesuccess, the definitive treatment for cecal volvulus is righthemicolectomy with primary anastomosis in the appropriate setting

with resection, ileostomy, and mucous fistula in the presence ofperforation or peritonitis

A i l h lth 22 ld l ll f tb ll l t t

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A previously healthy 22-year-old male college football player presents to your emergencydepartment 24 h after the homecoming football game with complaints of severe left

lower quadrant abdominal pain, fever of 102F, nausea and vomiting. Laboratory findingsinclude a WBC count of 16,300 with 7% bands. On physical examination his abdomen is

soft, but he has marked tenderness in the left lower quadrant.Which of the following is the most appropriate diagnostic study in this patient?

(A) CT abdomen and pelvis

(B) barium enema

(C) abdominal ultrasound

(D) colonoscopy

(E) laparoscopy

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Explanation:

This patient has acute uncomplicated diverticulitis. This disease is characterized bylocalized diverticular perforation without abscess formation, free perforation, orbleeding. The majority of patients present with left lower quadrant pain, fever, and leukocytosis,making diverticulitis principally a clinical diagnosis. Diagnostic dilemmas do occur, however, and awide differential including bowel perforation or obstruction, appendicitis, inflammatory boweldisease, and ischemic colitis must be considered. An imaging study is indicated when the clinicalpicture is not clear, or to help guide future therapy.

Endoscopy is contraindicated in the setting of acute diverticulitis because the insuflation requiredcan disturb the tenuous seal containing the diverticular perforation and result in the conversion tofree perforation and a need for more urgent surgical intervention with substantially highermorbidity and mortality. Endoscopy can be useful after the acute episode has resolved toevaluate for other distal pathologic processes.

Barium enema is also contraindicated in the acute setting for reasons similar to those describedabove. It is a very important part of the preparation for elective resection after recovery, as itaccurately describes the extent of involvement and severity of disease, including strictures thatmay develop after acute diverticulitis.

Laparoscopy has been described as a highly sensitive diagnostic modality; however, its invasivenature precludes its routine use for this purpose.

Both CT and ultrasound can accurately diagnose diverticulitis. CT has a sensitivity of up to 95%and specificity of 72%. Both modalities can also identify abscesses, making it possible for patientsto have early drainage of these collections. CT is generally more available in most institutions andis substantially less operator-dependent. CT findings such as presence of an abscess, extraluminalcontrast or air strongly suggest that conservative treatment with antibiotics will not be successful.

A 73 year old male presents to your emergency department

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A 73-year-old male presents to your emergency departmentcomplaining of a large amount of bright red blood per rectum. He ismoderately tachycardic, but otherwise is hemodynamically stable.

Which of the following statements regarding the management of this

patient is false?

A) Anoscopy followed by proctoscopy should be performedto exclude localized anorectal disease as the cause ofhemorrhage.

(B) Before surgical intervention is considered, he must

undergo esophagogastroduodenoscopy (EGD).

(C) He should undergo colonoscopy if clinically stable.

(D) A positive tagged RBC scan should prompt segmentalsurgical resection.

(E) None of the above.

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Explanation:

LGIH is defined as persistent gross bleeding from the rectum, with or withouthemodynamic instability and hemorrhagic shock. This patient has early signs ofhemodynamic instability, so aggressive resuscitation must be undertaken prior toengaging in any diagnostic studies. Anoproctosigmoidoscopy is the next step in hisevaluation and management. Occasionally, localized and treatable lesions of the anusmay be responsible for the hemorrhage. In hemodynamically stable patients, the next

step would be to pursue colonoscopy. This study can identify active bleeding orstigmata of recent bleeding in up to 90% of patients. Endoscopic hemostasis can beattempted, although the success rate varies with the type of lesion (angiodysplasiashave 8590% success rate).

In stable patients, EGD can be deferred until after colonoscopy, but it remains anessential part of the evaluation, and with 515% of LGIH caused by upper GI bleed,it must be performed before surgical intervention is considered.

Tagged RBC scan allows for identification of the source of bleeding down to 0.1

mL/min; however, localization of these findings is somewhat vague, makingsegmental surgical resection based on bleeding scan alone a risky proposition.Findings should be correlated with a mesenteric arteriogram or the endoscopistshould label the area with dye while performing the colonoscopy.

An 80-year-old female presents to the emergency room with abdominal pain. She complains that the pain seems to beradiating to the right thigh, knee, and hip. She also has nausea and vomiting that is bilious in nature. Although this pain has

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g g g p g g pbeen intermittent for the past year, she believes that this episode is more severe, which prompted her to seek assistance at

the emergency room. She denies any history of prior surgery. However, she suffers from diabetes mellitus and had amyocardial infarction in the past. On physical examination, the patient is tachycardic, normotensive, and afebrile. Abdominal

examination reveals a distended abdomen, with guarding, rebound, diffuse tenderness and high pitched bowel sounds. Noobvious umbilical, nor inguinal hernias were detected. A palpable mass was discovered high in the medial aspect of the right

thigh. What is your diagnosis

A) femoral hernia

(B) mesenteric ischemia(C) obturator hernia

(D) ruptured appendicitis

(E) lymphoma

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Explanation

: Obturator hernias accounts for less than 5% of all mechanical bowel obstructions. Itis most commonly found in females, on the right side, in the seventh and eighthdecade of life. The hernia passes through the obturator canal, bounded by thesuperior pubic ramus and the obturator membrane. The obturator vessels and nervepasses through the canal and they lie posterolateral to the hernia sac. There are fourcardinal features of this hernia, the most common being intestinal obstruction;

another is the Howship-Romberg sign (pain down the inner surface of thigh, kneejoint, and hip). This is referred pain from the cutaneous branch of the anteriordivision of the obturator nerve, which is compressed by the hernia in the canal. Thenext feature is a palpable mass high in the medial aspect of the thigh at the origin ofthe adductor muscles. The mass is best felt with the thigh flexed, adducted, androtated outward. The last feature is repeated attacks of intestinal obstruction thatpass spontaneously. Treatment entails operative intervention as soon as possible,secondary to the high rate of strangulation. The three preferred operative

approaches are a midline transperitoneal approach, midline extraperitoneal approach,and exposure in the thigh. The former two are better since these hernias can bebilateral and therefore one can explore the other side if needed. Figures 26-2 and 26-3 show the classical radiologic findings of an incarcerated obturator herniacausingsmall bowel obstruction.

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A 65-year-old male with a history of peptic ulcer disease presentswith an acute onset of epigastric pain and hematemesis. Hereports relief with antacids and proton pump inhibitors for 1 year.His past medical history is significant for hypertension andcoronary artery disease. On physical examination, the patient is

hypotensive, and tachycardic. His abdomen is soft and tender atthe epigastric region, but otherwise benign. Endoscopy reveals alarge amount of clot in the stomach with an active arterial bleederin the area of the duodenal bulb. Multiple attempts of endoscopictherapy failed. The patient continued to require additional IV fluidsand blood products. He was taken to the operating room, where alaparotomy was performed. A longitudinal incision along thepylorus spanning 3 cm on each side of the great vein of Mayo was

created. Traction sutures were placed superiorly and inferiorlyprior to the enterotomy. The ulcer was readily identified at theposterior duodenal bulb and a clot was removed. What is the nextstep in the procedure?

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(A) sclerotherapy

(B) perform a figure of eight stitch

(C) vasopressin infusion

(D) three suture ligation encompassing the proximal anddistal branches of the gastroduodenal arteries and a U-type stitch to transfix the transverse branch of the

pancreatic artery.(E) Kocherize the duodenum and perform a grahampatch

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Explanation: This is an example of a bleeding duodenal ulcer in theposterior wall. There are some studies that state that the incidence ofemergent or urgent operations for bleeding duodenal ulcers has remainedunchanged over the past years. Most patients with this disorder aresuccessfully treated with medical or endoscopic management. Endoscopyremains the initial standard of care for the diagnosis and treatment ofbleeding duodenal ulcers. Surgery is indicated when there is activehemorrhage which is refractory to endoscopic techniques. Initialmanagement should include replacement of blood volume by large bore IVsas well as continuous monitoring of vital signs and urinary output.Emergent surgery is also indicated when transfusion is in excess of 6 unitsin a 24-h period. Antrectomy and vagotomy was historically considered thegold standard for this condition secondary to low recurrence rate, but has

been replaced by the three suture technique, which has a significantly lowermorbidity and mortality in the elderly, and unstable patient. With thistechnique, we add pyloroplasty and truncal vagotomy. A highly selectivevagotomy can be done for the young, hemodynamically stable patient withminimal comorbidities

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A 50-year-old male presents to the emergency room with ahistory of melena, and most recently 3 episodes ofhematemesis. The patient denies attacks of reflux or historyof peptic ulcer disease. He has no other significant medicalproblems. He had a right inguinal hernia repair 10 years

ago. The patient's vital signs are stable. Physical exam ofthe abdomen was unremarkable. Rectal examinationreveals a positive fecal occult blood test. At this point in theexam, the patient retches and vomits approximately 250 ccof maroon emesis with specks of blood. Endoscopy reveals alarge submucosal vessel along the lesser curvature that is

not actively bleeding. What is the management for thiscondition?

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A) endoscopic cauterization

(B) vagotomy and antrectomy

(C) wedge resection of gastric wall

(D) distal gastrectomy without vagotomy

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Explanation: This is an example of Dielafoy's lesion, which is a vascularmalformation and a rare cause of upper GI hemorrhage. It is also called"caliber-persistent artery." The malformation is a large submucosal ormucosal vessel that may bleed when there is erosion into it. It is usuallyfound along the lesser curvature, middle aged individuals, and noassociation with any vascular, or peptic ulcer disease. The hemorrhageproduced from the lesion can be massive and can cease spontaneously attimes. It is difficult to diagnose endoscopically because there is no ulcersurrounding the lesion. Diagnosis is best achieved by performing endoscopyat the time of bleeding and visualizing a pinpoint mucosal defect with blood.Once the lesion is identified, the area is marked with India ink to delineatethe area during surgical resection. Definitive management calls for wedgeresection of the gastric wall, rather than an extended blind gastric

resection. Vagotomy is not required since it is not associated with pepticulcer disease. Endoscopic ablation with sclerotherapy or electrocoagulationhas proved unsuccessful for this lesion. Surgery is required because ofrecurrent bouts of hemorrhage. Angiography and embolectomy are nowalso being used as first line therapy.

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How should locked or perched facets in the cervical spine betreated initially?

(A) open reduction and internal fixation

(B) closed reduction with cervical traction

(C) keep patient immobilized in cervicalcollar

(D) no treatment is needed

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Explanation:

Severe flexion injuries of the cervical spine may cause unilateral or bilateral lockedfacets. Typically, unilateral locked facets result from flexion plus rotation injuries, andbilateral locked facets result from hyperflexion injuries. Anatomically, locked facetsrefer to the condition when the inferior articular facets of the upper dislocatedvertebra slide forward over the superior facets of the vertebra below (Fig. 9-16).Bilateral locked facets are extremely unstable given the extensive amount of

ligamentous injury involved. The forces applied in this type of injury rupture theposterior ligamentous complex, the joint capsules, the intervertebral disc, and,usually, the posterior and anterior longitudinal ligaments. In about 80% of thesecases, the patients will present with complete spinal cord injuries. Nerve root injuriesare common as well. Unilateral locked facets are more stable than bilateral, andthese patients are usually neurologically intact. Patients in either of these groupsshould be treated initially with closed reduction using cervical traction. Oncereduction of the cervical spine is achieved, patients may be stabilized byimmobilization in a halo vest or by internal fixation and fusion. Surgical managementis often preferred given the high incidence of unsatisfactory fusion when using a halovest alone. Surgical management should be used if attempts at closed reduction areunsuccessful. MRI is helpful in evaluating for a herniated disc and determining theextent of damage to the spinal cord (Fig. 9-17). It is also useful for preoperativeplanning. Perched facets refer to facets that have just reached the point of lockingwithout actually doing so. These injuries are treated in a similar manner to lockedfacets.

29-year-old male restrained passenger is brought to the ER in stable condition followinga moto ehicle accident He is admitted fo obse ation follo ing an abdominal CT

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a motor vehicle accident. He is admitted for observation following an abdominal CTdemonstrating a moderate amount of free fluid in the pelvis. Within 48 h, patient

develops worsening abdominal pain and undergoes exploratory laparotomy. A smallbowel perforation is identified (Fig. 10-4). Which of the following statements regarding

small bowel injuries is notcorrect?

(A) thought to occur when bowel is crushed againstspine

(B) frequently associated with lumbar spine fractures

(C) decreased incidence since the mandatory seat beltlaws

(D) believed result of closed loop of bowel under highintraluminal pressure

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Explanation:

Small bowel injuries secondary to blunt abdominal trauma areincreasing in incidence because of high velocity motor vehicleaccidents and mandatory seat belt laws (Moore, Feliciano, andMattox, 2004). The "seat belt" syndrome is the complex of injuries,which includes lumbar fractures and small bowel injuries. Physical

finding of ecchymoses along the anterior abdominal wall is referredto as the "seat belt sign" and may indicate underlying small bowelinjuries (Appleby and Nagy, 1989).

The proposed mechanisms of injury include (1) crushing of bowelagainst spine, (2) tearing of bowel from mesentery by suddendeceleration, and (3) rupture of a closed loop of bowel under high

intraluminal pressure (Guarino, Hassett, and Luchette, 1995).

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An ER thoracotomy should notbe performed in what setting?

(A) a patient in shock with a penetrating anterior chest wound

(B) a patient who sustained a penetrating chest wound anddevelops precipitous shock after endotracheal intubation andpositive-pressure ventilation

(C) a pulseless patient with a penetrating chest wound suspected tohave a massive hemothorax

(D) a patient arriving with no electrocardiogram (ECG) rhythm withknown blunt trauma to the chest

E) C and D

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Explanation: The primary objectives of resuscitative thoracotomy are (a) release of percardial tamponade; (b)

control of intrathoracic vascular or cardiac bleeding; (c) eliminate massive air embolism orbronchopleural fistula; (d) perform open cardiac massage; and (e) temporarily occlude thedescending thoracic aorta. A left anterolateral thoracotomy incision is preferred. A rightthoracotomy is reserved for hypotensive patients with penetrating injuries to the right chest inneed of direct access to massive blood loss or air embolism. An ER thoracotomy is initiated at thelevel of fourth to fifth intercostal space with the proper level corresponding to inferior border of

pectoralis major muscle. The incision is made through the intercostal muscle and parietal pleurais divided along superior margin of the rib. The rib retractor is inserted with the handle towardthe axilla. Key resuscitative maneuvers are then initiated.

A pericardiotomy incision is made in the presence of cardiac tamponade and incised widely,anterior and parellel to the phrenic nerve. Blood clots are evacuated from the pericardium andcardiac bleeding sites should be controlled immediately with digital pressure on the surface of theventricle and partially occluding vascular clamps placed on atrium or great vessels. In beatinghearts, efforts at cardiorrhapy should be delayed until initial resuscitation measures have beencompleted. In the nonbeating heart, suturing should be performed prior to defibrillation.

Temporary control of the bleeding can be accomplished with a skin-stapling device. Cardiacwounds are best repaired with 3-0 nonabsorbable horizontal mattress sutures in the operatingroom.

In cardiac arrest, bimanual internal massage of the heart should be instituted. If internaldefibrillation does not restore vigorous cardiac activity, the descending thoracic aorta should beincompletely cross-clamped at the level inferior to the left pulmonary hilum to maximize coronaryperfusion. Cardiopulmonary collapse from suspected intraabdominal hemorrhage should betemporized by occlusion of the descending thoracic aorta. Air embolism should be suspected in apatient with penetrating chest trauma who develops precipitous shock after endotrachealintubation and positive-pressure ventilation. Treatment involves pulmonary hilar cross-clamping,vigorous cardiac massage, along with aortic root and left ventricle air aspiration (Moore,Feliciano and Mattox 2004 .

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An unrestrained 23-year-old male drag racer involved in high-speed motor vehicle

accident presents to ER with intense pain in right chest. The primary surveydemonstrates decreased breath sounds over the right hemithorax with noted paradoxical

motion of the right chest wall during respiration (Fig. 10-5). The major pathologic

sequela of this injury is

A) disruption of ventilation because of paradoxicalmotion of the chest wall

(B) bleeding from disruption of intercostal vessels

(C) underlying pulmonary contusion

(D) pneumothorax

(E) splinting from chest wall pain

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Explanation:

A flail chest consists of segmental fractures of three or more adjacent ribs, or one or more rib fractures with associatedcostrochondral separation or fracture of sternum (Fig. 10-5). This causes an unstable or floatingsegment of chest wall that moves paradoxically during respiration (ATLS, 1997). A pneumothoraxor hemothorax may be present. A more significant injury, however, is associated with pulmonarycontusion leading to hemorrhage and edema of the injured lung. A chest wall injury of thismagnitude is also associated with significant pain, and respiratory efficiency is reduced.

Treatment is directed toward reversing hypoventilation caused by the pain, and hypoxia caused

by the associated pulmonary contusion. Careful monitoring of ventilation and oxygenation isrequired, and often time intubation and ventilatory support may be indicated in 2040% ofpatients. Control of pain because of multiple rib fractures by using regional anesthetic techniquessuch as intercostal nerve block, insertion of intrapleural catheter, or insertion of an epiduralcatheter is important to improve respiratory mechanics. Rarely is physical stabilization of chestwall necessary (Moore, Feliciano, and Mattox, 2004).

BibliographyMoore E, Feliciano D, Mattox K. Trauma, 5th ed. New York, NY: McGraw-Hill, 2004.

American College of Surgeons Committee on Trauma.American Trauma Life Support, 6th ed.Chicago, IL: American College of Surgeons, 1997.