第三十二章 腹腔镜手术的麻醉

Chapter 32

Anesthesia for laparoscopic Surgery

湘雅临床麻醉教研室

• The field of abdominal surgery has been radically changed with the introduction of laparoscopy.

• Recent advance in robotic and video technology have made the use of laparoscopic procedures more widely applicable.

• With the evolution of laparoscopy ， a substantial number of abdominal procedures are being performed using this approach, including cholecystectomy, myomectomy, and so on.

• Compared with the traditional open abdominal approach.the laparoscopic approach is:

• less postoperative pain.

• shorter hospital stay.

• fewer overall adverse event.

• more rapid return to normal activity

• significant cost savings.

• However, it is important that the benefits of laparoscopic procedures be weighed against associated complications.

• A thorough knowledge of potential perioperative complications is necessary to provide optimal patient care

Part I Physiological changes during laparoscopic surgery

• The first step in laparoscopy is establishment of pneumoperitoneum.

• The ideal insufflating gas would be colorless, nonexplosive, Physiologically inert

and readily soluble

in plasma.

Part I Physiological changes during laparoscopic surgery

• CO2 is used extensively in clinic. The speed and pressure of the pneumoperitioneum effect the absorption of CO2.

• Positioning changes will effect the physiological function.

I. Cardiovascular system

The pressure of pneumopertioneum effect three aspects .

systemic vascular resistance (SVR. Afterloail).

venous return (preload ). cardiac function.

I. Cardiovascular system

During laparoscopic cholecystectomy

• If intraabdominal pressure (IAP) >10mmHg CVP ↑PAWP↑ SVR↑ CO and MAP↑ If intraabdominal pressure (IAP) >20mmHg CVP ↓ SVR↑↑ CI CO↓ MAP↑↓or normal

I. Cardiovascular system

• The cause :

Intraabdominal positive pressure intrathoracic pressure cardiac blood flow CO

IPPV or PEEP intrathoracic pressure CO

I. Cardiovascular system

• The arrhythmias during laparoscopy is approximately 14%, Bradyarrhythemias including bradycardia, nodal rhythm are attributed to a vagal response due to rapid insufflations.

2.The patients were placed in different body position (Table1)

• During cholecystectomy , the patient is placed on head-up about 10-20°.

2.The patients were placed in different body position (Table1)

• During gynecological surgery, the patient is placed on head-down position.

Table-1 Hemodynamic measurements before and during pneumoperitoneum （ PP ） during laparoscopic

cholecystectomy in healthy patients

Supine Head-down

Head-up Supine with pp

Head-down with pp

Head-up

With pp

Heart rate(beats/min)

61±7 53 ±4 66 ±9 66 ±16 53 ±3 70 ±8

MAP(mmHg) 69 ±7 76 ±6 64 ± 9 91 ±11 87 ±8 84 ±13

CVP(mmHg) 6.2 ±2.9 10.2 ±3.5 0.8 ±3.5 10.9 ±2.7 15.9 ±4.6 3.1 ±2.6

MPAP(mmHg) 14.1 ±1.5 17.4 ±1.2 8.5 ±3.5 18.4 ±3.7 20.0 ±6.1 10.8 ±2.5

SVR(dynes/sec/cm5)

1310 ±302 1381 ±313 1419 ±342 1795 ±444 1577 ±344 2047 ±430

3. Carbon dioxide absorption

The absorption of CO2 is influenc

ed significantly by

• duration of interoperation insufflations

• IAP and the solubility of CO2 .

3. Carbon dioxide absorption

Hypercarbia resulting from CO2 insufflations has direct and indirect homodynamic effects.

3. Carbon dioxide absorption

The direct effects include peripheral vasodilatation and depression of myocardial contractility.

The indirect effects include activation of the central nervous system and sympathizes system, which increase myocardial contractility and causes tachycardia and hypertension

II. Pulmonary function

Changes in pulmonary function with pneumoperitoneum : positioning anesthesia Elevation of diaphragm may be asso

ciated with reduction in lung volumes.

II. Pulmonary function

In patients undergoing laparoscopic

procedure with 15 degree head-down tilt, the total pulmonary compliance

decreased by 40%.

with 20 degree head-up tilt, the total pulmonary compliance decreased by 20%.

II. Pulmonary function

• Increased IAP and upward displacement of the diaphragm ca

n cause alveolar collapse and ventilation/perfusion mismatching,

resulting in hypoxemia and hypercarbia.

III. The other physiological changes

• Increased IAP can result in reduction in splanchenic and renal perfusion.

Hepatic blood flow is decreased .

III. The other physiological changes

Reduction in urine output.

the compression of renal vessel

increased plasma renin activity .

Increased IAP can result in

aspiration and regurgitation.

Part II Anesthesia for laparoscop

ic surgery

Ⅰ. Preoperative evaluation and preparation for anesthesia.

1. Evaluation Elderly, obesity, hypertension, coron

ary artery disease. Serious hypertension , cardiac dysfu

nction , COPD . The open surgery (open cholecystect

omy) duo to medical problem (serious hypercarbia).

Ⅰ. Preoperative evaluation and preparation for anesthesia.

2. Preparation and premedication Same as general surgery.

Meperidine and opioid is thought to cause sphincter of oddi spasm.

Atropine may help decease spasm.

H2 antagonist (ranitidine) may be given (the patient being at risk for gastric aspiration).

To open upper extremity vein.

Ⅱ.The choice of anesthesia

1.The principle of choice

The principle is rapidly, shorter, safety comfortable and return to a normal activity early.

General anesthesia is may be more suitable than other anesthesia.

Ⅱ.The choice of anesthesia

2.Method of anenthesiaA. General anesthesia Advantage: ① Proper depths of anesthesia. ② Effective ventilation. ③ To control the relax of muscle. ④ Adjusting MVV.

Ⅱ.The choice of anesthesia

Anesthetic Management

The endotracheal intubation is suggested.

An oral gastric tube should be inserted to ensure that gastric distension does not exist.

Ⅱ.The choice of anesthesia

Anesthetic agents. Propofol, Etomidate, Midazolam. Fentanyl, Remifentanyl, Succinyicholine Vecuronium Atracurium. Isoflurane, desflurane.

The use of N2O is controversial. It increases bowel distention, and produce conflicting results on the rate of N2O on postoperative nausea.

Ⅱ.The choice of anesthesia

B.Epidural anesthesia 。 A high level is required for complete

muscle relaxation 。 70prevent diaphragmatic irritation c

aused by gas insufflation and surgical manipulations.

Ⅱ.The choice of anesthesia

B.Epidural anesthesia 。 Serious respiratorg depression is possib

le * a high regional block * the use of opioid * the diaphragm is rised during

insufflation. The occasional occurrence of referred s

houlder pain

Ⅱ.The choice of anesthesia

C. General Aesthesia and Epidural

anesthesia.

D. Regional anesthesia.

Ⅲ.Perioprative monitoring

• Cardiovascular function

• Respiratory function

• Urinary volume

• Neuromuscular transmission

Ⅳ.Special considerations in the anesthesia

• Control of intra-abdominal pressure

* laparoscopic cholecystetomy, IAP10-15mmHg

• Prevention of aspiration of gastric contents.

* Gynecologic laparoscopy ， IAP20- 40mmHg

* obesity ， abdominal wall lift is used

Ⅳ.Special considerations in

the anesthesia

• Position

Laparoscopic cholecystetomy ， supine is placed ， reverse trendelenburg with right side elevates.

Gynecologic laparoscopy, head-down and feet-up.

Ⅳ.Special considerations in the anesthesia

* Enhance respiratory management during operation

* The use of neuromuscular blockers and complete muscle relaxation are required

Ⅳ.Special considerations in the anesthesia

• If it is not possible to complete the laparoscopic procedure, for example : a major abdominal vessel lacerated ,peritonitis and hemorrhage, a open surgery will be performed.

Ⅳ.Special considerations in the anesthesia

• Epidural anesthesia represent alternative for laparoscopic surgery. But a high level is required. A disadvantage is the occurrence of referred shoulder pain.

Ⅳ.Special considerations in the anesthesia

• After operation, the residual pheumoperitoneum should be discharged.

• Prevention of the regurgitation of gastric contents

PART .COMPLICATIONⅢ1.Cardiovescular system

* hypertention * bradycardia * tachycardia

PART .COMPLICATIONⅢ

2. Hypoxemia, Hypercarbia and Acidosis

* High LAP * Head-down position * morbid obesity * COPD (chronic obstructive pulmonary disease) * mechanical ventilation

PART .COMPLICATIONⅢ

3.CO2 embolism * The most common cause of clinically

apparent co2 embolism is inadvertent intravascular placement of the needle

* An open vein has a lower pressure than the surrounding pressure

PART .COMPLICATIONⅢ4.Regurgitation and aspiration * High LAP * Change of position * Epidural and spinal aneasthesia

PART .COMPLICATIONⅢ5.Nausea and vomiting

They are common following laparosc

opic procedures. Pharmacologic prophylaxis is recom

mended, for example ： Renitidine ， Droperidol ， ondansetron.