第三十二章 腹腔镜手术的麻醉 Chapter 32 Anesthesia for laparoscopic Surgery,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 MAPor 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,3. Carbon dioxide absorption,The absorption of CO2 is influenced 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 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,. 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).,. 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.,.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.,.The choice of anesthesia,2.Method of ane