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 CO 2 is used extensively in clinic. The speed and pressure of the pneumoperitioneum effect the absorption of CO 2. 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 SupineHead- down Head-upSupine with pp Head-down with pp Head-up With pp Heart rate(beats/mi n) 61±753 ±466 ±966 ±1653 ±370 ±8 MAP(mmHg)69 ±776 ±664 ± 991 ±1187 ±884 ±13 CVP(mmHg)6.2 ± ± ± ± ± ±2.6 MPAP(mmHg)14.1 ± ± ± ± ± ±2.5 SVR(dynes/sec/ cm 5 ) 1310 ± ± ± ± ± ±430

3. Carbon dioxide absorption The absorption of CO 2 is influenced significantly by duration of interoperation insufflations IAP and the solubility of CO 2.

3. Carbon dioxide absorption Hypercarbia resulting from CO 2 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 associated 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 can 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 laparoscopic surgery

Ⅰ. Preoperative evaluation and preparation for anesthesia. 1. Evaluation Elderly, obesity, hypertension, coronary artery disease. Serious hypertension, cardiac dysfunction, COPD. The open surgery (open cholecystectomy) 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 anenthesia A. 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 N 2 O is controversial. It increases bowel distention, and produce conflicting results on the rate of N 2 O on postoperative nausea.

Ⅱ. The choice of anesthesia B.Epidural anesthesia 。 A high level is required for complete muscle relaxation 。 70prevent diaphragmatic irritation caused by gas insufflation and surgical manipulations.

Ⅱ. The choice of anesthesia B.Epidural anesthesia 。 Serious respiratorg depression is possible * a high regional block * the use of opioid * the diaphragm is rised during insufflation. The occasional occurrence of referred shoulder 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 Ⅲ.COMPLICATION 1.Cardiovescular system * hypertention * bradycardia * tachycardia

PART Ⅲ.COMPLICATION 2. Hypoxemia, Hypercarbia and Acidosis * High LAP * Head-down position * morbid obesity * COPD (chronic obstructive pulmonary disease) * mechanical ventilation

PART Ⅲ.COMPLICATION 3.CO 2 embolism * The most common cause of clinically apparent co 2 embolism is inadvertent intravascular placement of the needle * An open vein has a lower pressure than the surrounding pressure

PART Ⅲ.COMPLICATION 4.Regurgitation and aspiration * High LAP * Change of position * Epidural and spinal aneasthesia

PART Ⅲ.COMPLICATION 5.Nausea and vomiting They are common following laparoscopic procedures. Pharmacologic prophylaxis is recommended, for example ： Renitidine ， Droperidol ， ondansetron.