Physical Diagnosis

Cyanosis

DefinitionDefinitionCyanosisCyanosis refers to a bluish(refers to a bluish( 带蓝色带蓝色的；带青色的的；带青色的 )color of the skin and )color of the skin and mucous membranes resulting fromucous membranes resulting from an increased quantity of reducem an increased quantity of reduced hemoglobin(d hemoglobin( 亚铁血红蛋白；还原亚铁血红蛋白；还原血红蛋白血红蛋白 ), or of hemoglobin deriv), or of hemoglobin derivatives, in the small blood vessels oatives, in the small blood vessels of those areas. It is usually most mf those areas. It is usually most marked in the lips, nail beds(arked in the lips, nail beds( 甲床甲床 ), ), ears, and malar(ears, and malar( 颧骨的；颊的颧骨的；颊的 )em)eminences(inences( 隆起隆起 ). ).

Definition of cyanosis A bluish color of skin and mucous membranes, especially in lips, nail beds, and malareminences, caused by increased amount of reduced hemoglobin(Hb) or abnormalHb derivatives in small blood vessels.

Mechanism of Mechanism of CyanosisCyanosis

Cyanosis, especially if develCyanosis, especially if developed recently, is more comoped recently, is more commonly detected by a family monly detected by a family member than the patient. Tmember than the patient. The florid(he florid( 鲜红色的；气色好鲜红色的；气色好的的 ) skin characteristic of po) skin characteristic of polycythemia vera(lycythemia vera( 真性红细胞真性红细胞增多症增多症 ) must be distinguish) must be distinguished from the true cyanosis died from the true cyanosis discussed here. scussed here.

A cherry(A cherry( 樱桃樱桃 )-colored flus)-colored flush(h( 潮红潮红 ), rather than cyanos), rather than cyanosis, is caused by COHb(is, is caused by COHb(CarboCarboxyhemoglobin xyhemoglobin 碳氧血红蛋白碳氧血红蛋白 ). ).

The degree of cyanosis is mThe degree of cyanosis is modified by the color of the codified by the color of the cutaneous(utaneous( 皮肤的皮肤的 ) pigment ) pigment and the thickness of the skiand the thickness of the skin, as well as by the state of tn, as well as by the state of the cutaneous capillaries. he cutaneous capillaries.

The accurate clinical detectThe accurate clinical detection of the presence and degion of the presence and degree of cyanosis is difficult, aree of cyanosis is difficult, as proved by oximetric(s proved by oximetric( 血氧血氧定量法的定量法的 )studies.)studies.

In some instances, central cyanosIn some instances, central cyanosis can be detected reliably when tis can be detected reliably when the SaOhe SaO22 has fallen to 85%; in other has fallen to 85%; in others, particularly in dark-skinned pers, particularly in dark-skinned persons, it may not be detected until sons, it may not be detected until it has declined to 75%. In the latteit has declined to 75%. In the latter case, examination of the mucour case, examination of the mucous membranes in the oral cavity ans membranes in the oral cavity and the conjunctivae(d the conjunctivae( 结膜结膜 )rather th)rather than examination of the skin is moran examination of the skin is more helpful in the detection of cyanoe helpful in the detection of cyanosis.sis.

The increase in the quantity of The increase in the quantity of reduced hemoglobin in the mreduced hemoglobin in the mucocutaneous(ucocutaneous( 皮肤粘膜的皮肤粘膜的 ) ves) vessels that produces cyanosis masels that produces cyanosis may be brought about either by ay be brought about either by an increase in the quantity of ven increase in the quantity of venous blood as the result of dilanous blood as the result of dilatation of the venules(tation of the venules( 小静脉小静脉 ) a) and venous ends of the capillarind venous ends of the capillaries or by a reduction in the SaOes or by a reduction in the SaO22 in the capillary blood. in the capillary blood.

In general, cyanosis In general, cyanosis becomes apparent when becomes apparent when the mean capillary the mean capillary concentration of reduced concentration of reduced hemoglobin exceeds 50 hemoglobin exceeds 50 g/L (5g/dL). It is the g/L (5g/dL). It is the absoluteabsolute rather than the rather than the relativerelative quantity of quantity of reduced hemoglobin that reduced hemoglobin that is important in producing is important in producing cyanosis. cyanosis.

Thus, in a patient with severe aneThus, in a patient with severe anemia, the relative amount of reducmia, the relative amount of reduced hemoglobin in the venous blooed hemoglobin in the venous blood may be very large when consided may be very large when considered in relation to the total amount red in relation to the total amount of hemoglobin in the blood. Howeof hemoglobin in the blood. However, since the concentration of thver, since the concentration of the latter is markedly reduced, thee latter is markedly reduced, the aabsolutebsolute quantity of reduced hemoquantity of reduced hemoglobin may still be small, and therglobin may still be small, and therefore patients with severe anemia efore patients with severe anemia and even and even markedmarked arterial desatur arterial desaturation(ation( 稀释稀释 )do not display cyanosi)do not display cyanosis. s.

Conversely, Conversely, the higher the tthe higher the total hemoglobin content, thotal hemoglobin content, the greater is the tendency toe greater is the tendency toward cyanosisward cyanosis; thus, patient; thus, patients with marked polycythemis with marked polycythemia(a( 红细胞增多症红细胞增多症 )tend to be c)tend to be cyanotic at higher levels of Syanotic at higher levels of SaOaO22 than patients with nor than patients with normal hematocrit(mal hematocrit( 红细胞压积红细胞压积) values. ) values.

Likewise, local passive Likewise, local passive congestion, which causes congestion, which causes an increase in the total an increase in the total amount of reduced amount of reduced hemoglobin in the vessels hemoglobin in the vessels in a given area, may cause in a given area, may cause cyanosis. cyanosis.

Cyanosis also is observed Cyanosis also is observed when nonfunctional hemwhen nonfunctional hemoglobin such as oglobin such as methemomethemoglobinglobin(( 正铁血红蛋白，高正铁血红蛋白，高铁血红蛋白铁血红蛋白 )or )or sulfhemoglsulfhemoglobinobin(( 硫化血红蛋白硫化血红蛋白 ) is pre) is present in blood.sent in blood.

15

5

20

5 5 5

0

24

6

8

1012

14

16

1820

Total HbR-Hb

Normal Polycythemia Anemia

g/dl

Mechanisms of Cyanosis Caused by absolute increase of amount of reducedHb in blood, usually > 5g/dl (capillary) The higher the hemoglobin concentration, The greater tendency toward cyanosis.

Clinical Classification & Clinical Classification & EtiologyEtiology

True CyanosisTrue Cyanosis (increased amount of reduce(increased amount of reduced Hb)d Hb)

— — Central TypeCentral Type —— Peripheral Type Peripheral Type —— Mixed TypeMixed Type Cyanosis due to abnormal Hb derivativesCyanosis due to abnormal Hb derivatives —— Methemoglobinemia(Methemoglobinemia( 高铁血红蛋白血症 )

—— Sulfhemoglobinemia(Sulfhemoglobinemia( 硫化血红蛋白血症 )

  

CyanosisCyanosis may be may be subdivided into central and subdivided into central and peripheral types. In the peripheral types. In the centralcentral type, the SaOtype, the SaO2 2 is is reduced or an abnormal reduced or an abnormal hemoglobin derivative is hemoglobin derivative is present, and the mucous present, and the mucous membranes and skin are membranes and skin are both affected. both affected.

PeripheralPeripheral cyanosis is due cyanosis is due to a slowing of blood flow to a slowing of blood flow and abnormally great and abnormally great extraction of Oextraction of O2 2 from from normally saturated arterial normally saturated arterial blood. It results from blood. It results from vasoconstriction and vasoconstriction and diminished peripheral blood diminished peripheral blood flow, such as occurs in cold flow, such as occurs in cold exposure, shock, congestive exposure, shock, congestive failure, and peripheral failure, and peripheral vascular disease. vascular disease.

Often in these conditions the mucOften in these conditions the mucous membranes of the oral cavity ous membranes of the oral cavity or those beneath the tongue may or those beneath the tongue may be spared. Clinical differentiation be spared. Clinical differentiation between central and peripheral cybetween central and peripheral cyanosis may not always be simple, anosis may not always be simple, and in conditions such as cardiogand in conditions such as cardiogenic shock (enic shock ( 心源性休克心源性休克 )with pul)with pulmonary edema(monary edema( 肺水肿肺水肿 )there may )there may be a mixture of both types.be a mixture of both types.

Impaired pulmonary function1. Airway obstruction2. Pulmonary diseases3. Pleural( 胸膜的 )diseases

Right-to-left shunting of blood

Tetralogy of Fallot

Central Cyanosis

Peripheral CyanosisCaused by increased oxygen consumption in peripheral tissue. Vasoconstriction Low cardiac output Exposure to cold air or water Slowing of blood flow Right heart failure

Mixed Cyanosis(Central + Peripheral)

Cardiogenic Shock

Pulmonary Edema

Central CyanosisCentral Cyanosis Decreased SaODecreased SaO22 results from a marked reduction iresults from a marked reduction in the PaOn the PaO22. This reduction may be . This reduction may be brought about by a decline in the brought about by a decline in the FIOFIO22((fractionfraction of inspired oxygen 吸人氧气分数 )without sufficient compwithout sufficient compensatory alveolar(ensatory alveolar( 肺泡的肺泡的 ) hyperv) hyperventilation(entilation( 通气过度通气过度 ,, 换气过度换气过度 )to )to maintain alveolar POmaintain alveolar PO22. .

Cyanosis does not occur Cyanosis does not occur to a significant degree in to a significant degree in an ascent to an altitude of an ascent to an altitude of 2500 m (8000 ft) but is 2500 m (8000 ft) but is marked in a further marked in a further ascent to 5000 m (16,000 ascent to 5000 m (16,000 ft). The reason for this ft). The reason for this difference becomes clear difference becomes clear on studying the on studying the SS shape of shape of the Hb-Othe Hb-O22 dissociation dissociation curve. curve.

At 2500 m (8000 ft) the At 2500 m (8000 ft) the FIOFIO22 is about 120 mmHg, is about 120 mmHg, the alveolar POthe alveolar PO22 is is approximately 80 mmHg, approximately 80 mmHg, and the SaOand the SaO22 is nearly is nearly normal. normal.

However, at 5000 m However, at 5000 m (16,000 ft) the FIO(16,000 ft) the FIO2 2 and and alveolar POalveolar PO22 are about 85 are about 85 and 50 mmHg, and 50 mmHg, respectively, and the SaOrespectively, and the SaO22 is only about 75%. This is only about 75%. This leaves 25% of the leaves 25% of the hemoglobin in the arterial hemoglobin in the arterial blood in the reduced form, blood in the reduced form, an amount likely to be an amount likely to be associated with cyanosis associated with cyanosis in the absence of anemia. in the absence of anemia.

Similarly, a mutant hemoglSimilarly, a mutant hemoglobin with a low affinity for obin with a low affinity for OO22 (e.g., Hb Kansas) causes (e.g., Hb Kansas) causes lowered SaOlowered SaO22 and resultant and resultant central cyanosis.central cyanosis.

Seriously Seriously impaired pulmoimpaired pulmonary functionnary function, through per, through perfusion(fusion( 灌注灌注 ) of unventilate) of unventilated or poorly ventilated areas d or poorly ventilated areas of the lung or alveolar hypoof the lung or alveolar hypoventilation, is a common caventilation, is a common cause of central cyanosis. use of central cyanosis.

This condition may occur aThis condition may occur acutely, as in extensive pneucutely, as in extensive pneumonia or pulmonary edemamonia or pulmonary edema, or chronically with chroni, or chronically with chronic pulmonary diseases (e.g., c pulmonary diseases (e.g., emphysema emphysema 肺气肿肺气肿 ). In the ). In the last situation, secondary polast situation, secondary polycythemia(lycythemia( 红血球增多症红血球增多症 ) i) is generally present, and clus generally present, and clubbing(bbing( 杵状指 )of the fingers of the fingers may occur. may occur.

However, in many types of However, in many types of chronic pulmonary disease chronic pulmonary disease with fibrosis and obliteratiowith fibrosis and obliteration(n( 闭塞 )of the capillary vascof the capillary vascular bed, cyanosis does not ular bed, cyanosis does not occur because there is relatoccur because there is relatively little perfusion of undively little perfusion of underventilated areas.erventilated areas.

  Another cause of Another cause of reduced SaOreduced SaO22 is is shunting of systemic shunting of systemic venous blood into the venous blood into the arterial circuitarterial circuit.. Certain forms of Certain forms of congenital heart disease congenital heart disease are associated with are associated with cyanosis. cyanosis.

Since blood flows from a Since blood flows from a higher-pressure to a higher-pressure to a lower-pressure region, for lower-pressure region, for a cardiac defect to result a cardiac defect to result in a right-to-left shunt, it in a right-to-left shunt, it must ordinarily be must ordinarily be combined with an combined with an obstructive lesion distal to obstructive lesion distal to the defect or with the defect or with elevated pulmonary elevated pulmonary vascular resistance.vascular resistance.

The most common congeniThe most common congenital cardiac lesion associated tal cardiac lesion associated with cyanosis in the adult is with cyanosis in the adult is the combination of ventricuthe combination of ventricular septal defect and pulmolar septal defect and pulmonary outflow tract obstructinary outflow tract obstruction (on (tetralogy of Fallottetralogy of Fallot). ).

The more severe the obstructiThe more severe the obstruction, the greater the degree of rion, the greater the degree of right-to-left shunting and resultght-to-left shunting and resultant cyanosis. In patients with ant cyanosis. In patients with patent ductus arteriosus, pulmpatent ductus arteriosus, pulmonary hypertension, and right-onary hypertension, and right-to-left shunt, to-left shunt, differential cyandifferential cyanosisosis results; that is, cyanosis o results; that is, cyanosis occurs in the lower but not in thccurs in the lower but not in the upper extremities. e upper extremities.

Pulmonary arteriovenous Pulmonary arteriovenous fistulaefistulae may be congenital may be congenital or acquired, solitary or mulor acquired, solitary or multiple, microscopic or massitiple, microscopic or massive. The severity of cyanosis ve. The severity of cyanosis produced by these fistulae produced by these fistulae depends on their size and ndepends on their size and number.umber.

They occur with some frequeThey occur with some frequency in hereditary hemorrhagic ncy in hereditary hemorrhagic telangiectasia telangiectasia (( 毛细管扩张毛细管扩张 ). S). SaOaO2 2 reduction and cyanosis mareduction and cyanosis may also occur in some patients y also occur in some patients with cirrhosis, presumably as with cirrhosis, presumably as a consequence of pulmonary aa consequence of pulmonary arteriovenous fistulas or portal rteriovenous fistulas or portal vein-pulmonary vein anastomvein-pulmonary vein anastomose(ose( 吻合术吻合术 ).).

  In patients with cardiac or In patients with cardiac or pulmonary right-to-left pulmonary right-to-left shunts, the presence and shunts, the presence and severity of cyanosis severity of cyanosis depend on the size of the depend on the size of the shunt relative to the shunt relative to the systemic flow as well as systemic flow as well as on the Hb-Oon the Hb-O22 saturation of saturation of the venous blood. the venous blood.

With increased extraction With increased extraction of Oof O22 from the blood by from the blood by the exercising muscles, the exercising muscles, the venous blood the venous blood returning to the right side returning to the right side of the heart is more of the heart is more unsaturated than at rest, unsaturated than at rest, and shunting of this blood and shunting of this blood or its passage through or its passage through lungs incapable of normal lungs incapable of normal oxygenation intensifies oxygenation intensifies the cyanosis. the cyanosis.

Also, since the systemic vasculAlso, since the systemic vascular resistance falls with exercisar resistance falls with exercise, the right-to-left shunt is auge, the right-to-left shunt is augmented by exercise in patients mented by exercise in patients with congenital heart disease awith congenital heart disease and communications between tnd communications between the two sides of the heart. Secohe two sides of the heart. Secondary polycythemia occurs frendary polycythemia occurs frequently in patients with arteriquently in patients with arterial Oal O22 unsaturation and contrib unsaturation and contributes to the cyanosis.utes to the cyanosis.

Cyanosis can be caused by small aCyanosis can be caused by small amounts of circulating methemoglmounts of circulating methemoglobin and by even smaller amountobin and by even smaller amounts of sulfhemoglobin. Although thes of sulfhemoglobin. Although they are uncommon causes of cyanosy are uncommon causes of cyanosis, these abnormal hemoglobin piis, these abnormal hemoglobin pigments should be sought by spectgments should be sought by spectroscopyroscopy(( 分光镜检查 )when cyanoswhen cyanosis is not readily explained by malfis is not readily explained by malfunction of the circulatory or respiunction of the circulatory or respiratory systems. ratory systems.

Generally, digital clubbing Generally, digital clubbing does not occur with them. Tdoes not occur with them. The diagnosis of methemoglhe diagnosis of methemoglobinemia can be suspected obinemia can be suspected if the patient's blood remaiif the patient's blood remains brown after being mixed ns brown after being mixed in a test tube and exposed tin a test tube and exposed to air.o air.

Cyanosis due to abnormal Hb derivCyanosis due to abnormal Hb derivativesatives

MethemoglobinemiaMethemoglobinemia —— Hereditary: very rareHereditary: very rare —— Acquired: Acquired: >3g/dl>3g/dl in blood in blood - intake or exposure to some drugs o- intake or exposure to some drugs o

rr chemicals, such as sulfa drugs, nitchemicals, such as sulfa drugs, nit

riterite salt. salt. “ enterogenic cyanosis ”“ enterogenic cyanosis ” SulfhemoglobinemiaSulfhemoglobinemia — — Caused by some drugs or chemicals,Caused by some drugs or chemicals, — — Sulfhemoglobin Sulfhemoglobin > 0.5g/dl> 0.5g/dl in blood in blood

Approach to Patients with CyanosisApproach to Patients with Cyanosis Differentiation of central as opposed to peripheralDifferentiation of central as opposed to peripheral

Cyanosis Skin temp. Massage( 按摩 )or warming

Central Warm No change Peripheral Cool Cyanosis fades

Peripheral Peripheral CyanosisCyanosis

Probably the most Probably the most common cause of common cause of peripheral cyanosis is peripheral cyanosis is the normal the normal vasoconstriction vasoconstriction resulting from exposure resulting from exposure to cold air or water. to cold air or water.

When cardiac output is low, as When cardiac output is low, as in severe congestive heart failin severe congestive heart failure or shock, cutaneous vasocure or shock, cutaneous vasoconstriction occurs as a compeonstriction occurs as a compensatory mechanism so that blonsatory mechanism so that blood is diverted from the skin to od is diverted from the skin to more vital areas such as the cemore vital areas such as the central nervous system and hearntral nervous system and heart, and intense cyanosis associat, and intense cyanosis associated with cool extremities may ted with cool extremities may result. result.

Even though the Even though the arterial blood is arterial blood is normally saturated, the normally saturated, the reduced volume flow reduced volume flow through the skin and through the skin and the reduced POthe reduced PO22 at the at the venous end of the venous end of the capillary result in capillary result in cyanosis.cyanosis.

Arterial obstruction to an extremiArterial obstruction to an extremity, as with an embolus, or arteriolty, as with an embolus, or arteriolar(ar( 小动脉的小动脉的 ) constriction, as in co) constriction, as in cold-induced vasospasmld-induced vasospasm 血管痉挛血管痉挛 (R(Raynaud’s phenomenon), generalaynaud’s phenomenon), generally results in pallor(ly results in pallor( 苍白苍白 ) and cold) and coldness, but there may be associated ness, but there may be associated with cyanosis. Venous obstructiowith cyanosis. Venous obstruction, as in thrombophlebitis(n, as in thrombophlebitis( 血栓性血栓性静脉炎静脉炎 ), dilates the subpapillary v), dilates the subpapillary venous plexuses(enous plexuses( 丛丛 ) and thereby i) and thereby intensifies cyanosis.ntensifies cyanosis.

Approach to the PatientApproach to the Patient

  Certain features are Certain features are important in arriving at the important in arriving at the cause of cyanosis:cause of cyanosis:

  1. The history, particularly 1. The history, particularly the onset (cyanosis present the onset (cyanosis present since birth is usually due to since birth is usually due to congenital heart disease), congenital heart disease), and possible exposure to and possible exposure to drugs or chemicals that may drugs or chemicals that may produce abnormal types of produce abnormal types of hemoglobin.hemoglobin.

  2. Clinical differentiation of 2. Clinical differentiation of central as opposed to central as opposed to peripheral cyanosis. peripheral cyanosis. Objective evidence by Objective evidence by physical or radiographic physical or radiographic examination of disorders of examination of disorders of the respiratory or the respiratory or cardiovascular systems. cardiovascular systems. Massage or gentle warming Massage or gentle warming of a cyanotic extremity will of a cyanotic extremity will increase peripheral blood increase peripheral blood flow and abolish peripheral flow and abolish peripheral but not central cyanosis.but not central cyanosis.

  3. The presence or absence 3. The presence or absence of of clubbing of the digits. clubbing of the digits.

Clubbing without cyanosisClubbing without cyanosis is is frequent in patients with i frequent in patients with infectivenfective endocarditis and ulcerativ endocarditis and ulcerative colitis; e colitis; it may occasionally occur i it may occasionally occur in n healthy persons, and in so healthy persons, and in some me instances it may be occupa instances it may be occupational,tional, e.g., in jackhammer( e.g., in jackhammer( 手提手提钻钻 )) operators. operators.

The combination of cyanosiThe combination of cyanosis and clubbings and clubbing is frequent i is frequent in patients with congenital hn patients with congenital heart disease and right-to-lefeart disease and right-to-left shunting and is seen occast shunting and is seen occasionally in persons with pulionally in persons with pulmonary disease such as lunmonary disease such as lung abscess or pulmonary artg abscess or pulmonary arteriovenous fistulae. eriovenous fistulae.

In contrast, peripheral In contrast, peripheral cyanosis or acutely cyanosis or acutely developing central developing central cyanosis is cyanosis is notnot associated associated with clubbed digits.with clubbed digits.  

4. Determination of PaO4. Determination of PaO22 tension and SaOtension and SaO2 2 and and spectroscopic and other spectroscopic and other examinations of the blood examinations of the blood for abnormal types of for abnormal types of hemoglobin (critical in the hemoglobin (critical in the differential diagnosis of differential diagnosis of cyanosis).cyanosis).  

Cyanosis Cyanosis + Dyspnea(+ Dyspnea( 呼吸困难呼吸困难 ))

Disorders of respiratory or cardiovascular systeDisorders of respiratory or cardiovascular systemm

Cyanosis Cyanosis with mild or no dyspneawith mild or no dyspnea

MethemoglobinemiaMethemoglobinemia

SulfhemoglobinemiaSulfhemoglobinemia: : Spectroscopy helpfulSpectroscopy helpful

Cyanosis Cyanosis + clubbing+ clubbing

Severe, long durationSevere, long duration

Determination of arterial oxygen saturation Determination of arterial oxygen saturation

CLUBBINGCLUBBING

The selective bullous(The selective bullous( 大疱大疱的的 ,, 大泡的大泡的 ) enlargement of ) enlargement of the distal segments of the fithe distal segments of the fingers and toes due to prolifngers and toes due to proliferation of connective tissueeration of connective tissue, particularly on the dorsal , particularly on the dorsal surface, is termed surface, is termed clubbingclubbing; there is increased spongin; there is increased sponginess(ess( 海棉质海棉质 )) of the soft tissu of the soft tissue at the base of the nail.e at the base of the nail.

Clubbing may be hereditary, idioClubbing may be hereditary, idiopathic, or acquired and associated pathic, or acquired and associated with a variety of disorders, includwith a variety of disorders, including cyanotic congenital heart diseing cyanotic congenital heart disease, infective endocarditis, and a ase, infective endocarditis, and a variety of pulmonary conditions (variety of pulmonary conditions (among them primary and metastaamong them primary and metastatic lung cancer, bronchiectasis(tic lung cancer, bronchiectasis( 支支气管扩张气管扩张 ), lung abscess, cystic fib), lung abscess, cystic fibrosis(rosis( 囊肿性纤维化囊肿性纤维化 ), and mesothe), and mesotheliomalioma 间皮瘤间皮瘤 ), as well as with som), as well as with some gastrointestinal diseases (include gastrointestinal diseases (including regional enteritis, chronic ulcing regional enteritis, chronic ulcerative colitis, and hepatic cirrhoserative colitis, and hepatic cirrhosis).is).

Bleeding in Skin & Mucous MembranesBleeding in Skin & Mucous Membranes

Introduction of BSMMBSMM is caused by the abnormalities of hBSMM is caused by the abnormalities of hemostasis(emostasis( 止血止血 ) and /or coagulation mech) and /or coagulation mechanisms, and characterized by local or exteanisms, and characterized by local or extensive mucocutaneous hemorrhage spontnsive mucocutaneous hemorrhage spontaneously or following slight trauma.aneously or following slight trauma.

According to its extent, therAccording to its extent, there are several types of BSMMe are several types of BSMM. Pinpoint hemorrhage, eq. Pinpoint hemorrhage, equal or less than 2mm in diaual or less than 2mm in diameter is called meter is called petechiaepetechiae; 3 ; 3 -5mm hemorrhagic lesion c-5mm hemorrhagic lesion called alled purpurapurpura; more than 5; more than 5mm, mm, ecchymosisecchymosis; local elev; local elevation and fluctuation, ation and fluctuation, hemahematomatoma..

Small pinpoint hemorrhageSmall pinpoint hemorrhages into the dermis due to the s into the dermis due to the leakage of red cells through leakage of red cells through capillaries are called capillaries are called petecpetechiaehiae and are characteristic and are characteristic of platelet disorders ¾ in paof platelet disorders ¾ in particular, severe thrombocytrticular, severe thrombocytopenia openia (( 血小板减少 症 血小板减少 症 ). ).

Larger subcutaneous collecLarger subcutaneous collections of blood due to leakagtions of blood due to leakage of blood from small arterie of blood from small arterioles and venules are called oles and venules are called ecchymosesecchymoses (common brui(common bruises) or, if somewhat deeper ses) or, if somewhat deeper and palpable, and palpable, hematomashematomas. .

They are also common in pThey are also common in patients with platelet defects atients with platelet defects and result from minor trauand result from minor trauma. Dilated capillaries, or ma. Dilated capillaries, or ttelangiectasiaelangiectasia, may cause bl, may cause bleeding without any hemosteeding without any hemostatic defect. atic defect.

In addition, the loss of connecIn addition, the loss of connective tissue support for capillaritive tissue support for capillaries and small veins that accomes and small veins that accompanies aging increases the fragpanies aging increases the fragility of superficial vessels, sucility of superficial vessels, such as those on the dorsum(h as those on the dorsum( 背部背部) of the hand, leading to extrav) of the hand, leading to extravasation(asation( 外渗外渗 ) of blood into su) of blood into subcutaneous tissue¾bcutaneous tissue¾senile(senile( 老老年的年的 ) purpura) purpura. .

Type and Clinical ManifestationType and Clinical Manifestation Petechia(Petechia( 出血点 ; 瘀点 ): : pinpoint pinpoint hemorrhahemorrha

gege Purpura(Purpura( 紫癜紫癜 ): > ): > 5mm5mm in diameterin diameter Ecchymosis(Ecchymosis( 瘀斑 ): common bruise, : common bruise, >10mm>10mm Hematoma(Hematoma( 血肿血肿 ): local ): local elevation elevation and and fluctufluctu

ationation bleeding in skin, mucous membrane, joibleeding in skin, mucous membrane, joi

nt cavity and viscera.nt cavity and viscera.

Petechiae

Purpura

Ecchymosis (Bruise)

Hematoma

Etiology & PathogenesisEtiology & Pathogenesis

Defects on the capillary wallDefects on the capillary wall Abnormalities of blood plateletsAbnormalities of blood platelets —— Quantitative platelets defectsQuantitative platelets defects —— Qualitative platelets defectsQualitative platelets defects Disturbance of coagulationDisturbance of coagulation —— Deficiency of coagulation factorsDeficiency of coagulation factors —— Increase of anti-coagulation Increase of anti-coagulation

substancessubstances

There are a lot of factoThere are a lot of factors participating in the rs participating in the process of the hemostprocess of the hemostasis and coagulation. asis and coagulation. Defects in one of folloDefects in one of following factors may lead wing factors may lead to BSMM.to BSMM.

First, extravascular factFirst, extravascular factoror: : Lack of tissue support to the Lack of tissue support to the vessel due to tissue degenerativessel due to tissue degeneration and atrophy may facilitate on and atrophy may facilitate BSMM. It is a rare cause of BSBSMM. It is a rare cause of BSMM, and is responsible for seMM, and is responsible for senile purpura and purpura in Cnile purpura and purpura in Cushing syndrome. ushing syndrome. In this situation both bleedin In this situation both bleeding time and coagulation time arg time and coagulation time are normal.e normal.

Second, the vascular factorSecond, the vascular factor The constriction of a small vessel pl The constriction of a small vessel plays a role in hemostasis and the pliabiays a role in hemostasis and the pliability of a vessel keeps it intact. If a smallity of a vessel keeps it intact. If a small vessel becomes fragile and fails to col vessel becomes fragile and fails to constrict after its damage, BSMM may onstrict after its damage, BSMM may occur. For example, in allergic purpuraccur. For example, in allergic purpura, Non-thrombocytopenic purpura due , Non-thrombocytopenic purpura due to infection or vitamine C deficiency ato infection or vitamine C deficiency and hereditary telangiectasis, vascular nd hereditary telangiectasis, vascular factor is the contributory cause of BSfactor is the contributory cause of BSMM.MM. In this situation, BT and CT are nor In this situation, BT and CT are normal, but capillary fragility test is positmal, but capillary fragility test is positive.ive.

Defects on Capillary WallDefects on Capillary Wall Fragile, or failure to constrictioFragile, or failure to constrictio

n after damagen after damage Allergic purpura; Allergic purpura; Hereditary telangioectasia;Hereditary telangioectasia; Non- thrombocytopenic purpuraNon- thrombocytopenic purpura —— Severe infectionSevere infection —— Vitamin C deficiencyVitamin C deficiency —— Uremia(Uremia( 尿毒症尿毒症 ))

The Third factor is the platelet defThe Third factor is the platelet defectsects..Blood platelets play an important Blood platelets play an important role in hemostasis. Platelet defectrole in hemostasis. Platelet defects can be divided into two types, ths can be divided into two types, the quantitative type and qualitative e quantitative type and qualitative type. In the former one, the blood type. In the former one, the blood platelet count (or BPC) is lower thplatelet count (or BPC) is lower than normal, that is, thrombocytopan normal, that is, thrombocytopenia(enia( 血小板减少症 ). In the latter o. In the latter one, BPC is normal, but its functione, BPC is normal, but its function is abnormal, as in thrombasthen is abnormal, as in thrombasthenia(nia( 血小板无力 )..

In platelet defects, In platelet defects, BPC is often lower, BPC is often lower, occasionally it is occasionally it is normal. Bleeding time is normal. Bleeding time is prolonged and clot prolonged and clot retraction is poor.retraction is poor.

Abnormalities of Blood Abnormalities of Blood PlateletsPlatelets

Quantitative platelets defectsQuantitative platelets defects — — BPC is low, as thrombocytopenia BPC is low, as thrombocytopenia

with various causeswith various causes

Qualitative platelets defectsQualitative platelets defects —— Platelets dysfunction, as thrombastPlatelets dysfunction, as thrombast

henia(henia( 血 小板无力 )

The final cause is the The final cause is the deficiency of deficiency of coagulation factors.coagulation factors.

The mechanism of coagThe mechanism of coagulation is complex.There ulation is complex.There are at least twelve coagulare at least twelve coagulation factors that participation factors that participate in coagulation.This prate in coagulation.This process can be roughly diviocess can be roughly divided into three stages.ded into three stages.

The First stage is applieThe First stage is applied to the formation of actid to the formation of activated thrombokinase. In vated thrombokinase. In the second stage, thrombthe second stage, thrombokinase converts prothrookinase converts prothrombin into thrombin. In tmbin into thrombin. In the final stage, thrombin ihe final stage, thrombin in turn converts fibrinogen turn converts fibrinogen into fibrin. n into fibrin.

Any failure in this procesAny failure in this process may result in coagulopas may result in coagulopathythy 凝血病 ..Most of the coagulation dMost of the coagulation disorders are congenital,sisorders are congenital,such as hemophilia. In clauch as hemophilia. In classic hemophilia, there is ssic hemophilia, there is the deficiency of coagulatthe deficiency of coagulation factor . ion factor .

A few of coagulation A few of coagulation disorders are acquired, disorders are acquired, such as liver diseases, such as liver diseases, as we know most of as we know most of coagulation factors are coagulation factors are made by liver. In this made by liver. In this situation, coagulation situation, coagulation time is prolonged.time is prolonged.

Disturbance of Disturbance of CoagulationCoagulation

I. Formation of activated thrombokinaseI. Formation of activated thrombokinase

II. Prothrombin II. Prothrombin ThrombinThrombin

III. Fibrinogen III. Fibrinogen FibrinFibrin Deficiency of coagulation factorsDeficiency of coagulation factors —— Congenital : HemophiliaCongenital : Hemophilia —— Acquired : Severe liver diseaseAcquired : Severe liver disease Increase of anti-coagulation substancesIncrease of anti-coagulation substances — — During anti-coagulation therapyDuring anti-coagulation therapy

Approach to patients with Approach to patients with BSMMBSMM is a complex is a complex problem, here we only problem, here we only discuss a few key points.discuss a few key points.

In history-taking, we In history-taking, we should ask whether should ask whether bleeding is spontaneous bleeding is spontaneous or following trauma, ask or following trauma, ask about past history of about past history of bleeding tendency, such bleeding tendency, such as bleeding after tooth as bleeding after tooth extraction, and ask extraction, and ask whether there is liver whether there is liver disease. disease.

In physical In physical examination, bleeding examination, bleeding should be traced over should be traced over whole body, sometimes whole body, sometimes including urine and stool. including urine and stool. In addition, the jaundice In addition, the jaundice and the size of liver and and the size of liver and spleen should be noted. spleen should be noted. Capillary fragility test is Capillary fragility test is helpful if some vascular helpful if some vascular factor is suspected.factor is suspected.

Laboratory routine Laboratory routine tests, including blood tests, including blood routine, blood platelet routine, blood platelet count, bleeding time, and count, bleeding time, and coagulation time, should coagulation time, should be done. If necessary, be done. If necessary, bone marrow study and bone marrow study and coagulation factors coagulation factors determination should be determination should be added.added.

Approach to Patients with Approach to Patients with BSMMBSMM

HistoryHistory —— Bleeding whether spontaneously or after Bleeding whether spontaneously or after

traumatrauma — — Past history of bleeding tendencyPast history of bleeding tendency —— Liver diseaseLiver disease Physical ExaminationPhysical Examination —— Jaundice,Jaundice, —— Size of liver and spleen, Size of liver and spleen, —— JointsJoints Laboratory TestsLaboratory Tests —— Blood routine, blood platelet count, bleeding Blood routine, blood platelet count, bleeding

time, time, —— Coagulation time, bone marrow studyCoagulation time, bone marrow study —— Coagulation factors determinationCoagulation factors determination