What anesthetic techniques can be used for laparo-scopic surgery?
General, regional, and local anesthesia have all been used successfully and safely for laparoscopy.
General anesthesia with endotracheal intubation and controlled ventilation is one of the more commonly used techniques. Here, the airway is protected and ETCO2 can be controlled to levels approximating 35 mmHg. IAP and airway pressures should be monitored. IAP should be kept below 20 mmHg, ideally between 12 and 15 mmHg. Increases in IAP should be avoided by ensuring an ade-quately deep plane of anesthesia. The need for muscle relax-ation is controversial. Peak inspiratory pressures >40 cm H2O predispose to barotrauma and should be reported to the surgeon if they occur. This is of particular importance in those with pre-existing bullous disease or in those with a history of barotrauma. The management of increased peak airway pressures may involve decreasing intra-abdominal pressure, lessening the Trendelenburg positioning, and decreasing tidal volumes and inspiratory flow rates.
The laryngeal mask airway (LMA) is an alternative to endotracheal intubation. This device does not protect the airway from aspiration of gastric contents. Controlled ven-tilation and monitoring of ETCO2 are possible. As peak air-way pressures are frequently greater than 20 cmH2O during these operations, there is no guarantee that the airway seal provided by the LMA will be preserved. Consequently, its use is strongly cautioned. If employed, it should be reserved for thin individuals without intrinsic increased risks for aspiration. In emergency situations, however, an airway maintained with an LMA is better than no airway at all.
Gynecologic laparoscopic procedures can be performed under spinal or epidural anesthesia. The advantage of regional anesthesia is the reduced need for sedatives and narcotics when compared with local anesthesia with supple-mental sedation. However, shoulder tip pain and discomfort secondary to abdominal distention are incompletely allevi-ated under epidural anesthesia. A sensory block from T4 to L5 is needed and may also be uncomfortable. The hemo-dynamic effects of the pneumoperitoneum under epidural anesthesia have not been studied. It is necessary to have a cooperative and motivated patient, a skilled laparoscopist, and minimal IAPs and Trendelenburg positioning for this method to be successful. Patients considered a “full stom-ach” are not the best candidates for this technique. The increases in intra-abdominal and intragastric pressures along with the frequently used Trendelenburg positioning and the need for significant intravenous sedation all increase the risks of regurgitation and potential aspiration when the airway is unprotected.
Local anesthesia with sedation offers several advantages compared with general anesthesia: quicker recovery, decreased incidence of postoperative nausea and vomiting, and fewer hemodynamic changes. The sequelae of general anesthesia, such as sore throat, muscle pain, and airway trauma, may also be avoided.
Success with local anesthesia also requires a relaxed, cooperative and motivated patient, a supportive operating room staff, and a skilled surgeon. Any laparoscopic proce-dure that requires multiple puncture sites, considerable organ manipulation, steep tilt, or extensive pneumoperi-toneum should not be managed with this method. Diagnostic laparoscopy and sterilization procedures are two operations that may be performed under this technique.