Anaesthetic problems during laparoscopic cholecystectomy

Subcutaneous emphysema--beyond the pneumoperitoneum

New additional risks factors that may act to increase the risk of subcutaneous emphysema include total gas volume, gas flow rate, valveless trocar systems, and robotic fulcrum forces.

Background:

Subcutaneous emphysema and gas extravasation outside of the peritoneal cavity during laparoscopy has consequences. Knowledge of the circumstances that increase the potential for subcutaneous emphysema is necessary for safe laparoscopy.

Methods:

A literature review and a PubMed search are the basis for this review.

Conclusions:

The known risk factors leading to subcutaneous emphysema during laparoscopy are multiple attempts at abdominal entry, improper cannula placement, loose fitting cannula/skin and fascial entry points, use of >5 cannulas, use of cannulas as fulcrums, torque of the laparoscope, increased intra-abdominal pressure, procedures lasting >3.5 hours, and attention to details. New additional risk factors acting as direct factors leading to subcutaneous emphysema risk and occurrence are total gas volume, gas flow rate, valveless trocar systems, and robotic fulcrum forces. Recognizing this spectrum of factors that leads to subcutaneous emphysema will yield greater patient safety during laparoscopic procedures.

Laparoscopic nephrectomy for benign non functioning kidneys

Laparoscopic nephrectomy has been established as the standard of care for the management of benign non-functioning kidneys and has gained worldwide popularity over the past decade. In this article, we have reviewed the current literature to elucidate the indications, contraindications, surgical techniques, results and complications of laparoscopic nephrectomy.

Anesthesia for laparoscopy with emphasis on outpatient laparoscopy

Laparoscopy has developed extremely rapidly and is currently applicable to virtually every surgical subspecialty. Most of the experience is with gynecologic laparoscopy, which has been performed for many years. Some of these procedures are simple and brief, with minimal gas insufflation. In these cases, respiratory compromise is limited, and spontaneous ventilation appears acceptable. Such procedures therefore can be performed with the patient under local or regional anesthesia, or using the LMA with general anesthesia, because the risk of aspiration is small. As laparoscopy has developed, more prolonged operations have become possible, but these normally require general anesthesia, controlled ventilation, and tracheal intubation. More sophisticated laparoscopic surgery has reduced postoperative morbidity, shortened hospital stays, and moved many procedures into the outpatient arena. These newer laparoscopic operations present many challenges, especially in the provision of adequate analgesia and the minimization of PONV. Analgesia should be multimodal, using local anesthesia and NSAIDs as first-line therapy. This combination may be sufficient for more minor procedures, and the elimination of opioids helps to reduce PONV. For more extensive operations, opioids also are required, but should not be the mainstay of analgesia. PONV should be treated effectively whenever it occurs, with consideration given to the use of prophylactic antiemetics in especially high-risk groups. Laparoscopic surgery clearly offers significant advantages in many cases. Although this technology can make some procedures technically possible on an outpatient basis, the morbidity following operations such as laparoscopic cholecystectomy is considerable. The ever-greater cost savings from the expansion of outpatient surgery is being achieved at the expense of patient discomfort and dissatisfaction. Extended care (23 h) could be a better option in some circumstances. The future will see further developments in laparoscopic surgery. Microlaparoscopy permits simple procedures to be performed with minimal analgesia and sedation in an office setting. At present, this technology allows only diagnostic and minor operative procedures, the stage at which conventional laparoscopy was in the early 1980s. Further developments in optical fibers could reduce the requirements for general anesthesia for other operations and substantially reduce postoperative morbidity. Until then, laparoscopy continues to present many challenges.

Effect of subcutaneous carbon dioxide insufflation on arterial pCO2

PURPOSE

Subcutaneous emphysema following laparoscopy could result in postoperative respiratory acidosis from prolonged CO2 absorption. We studied the magnitude and duration of alterations in PaCO2 coincident with direct CO2 insufflation into the subcutaneous fat of the anterior abdominal wall of 5 anesthetized juvenile pigs.

METHODS

First, each pig was insufflated with 6 L of CO2 to produce moderate emphysema over the trunk. Following return to baseline PaCO2, each pig was re-insufflated with 12 L of CO2 to produce severe emphysema over lower limbs, neck, head, and trunk. Measurements of arterial blood gases were performed every 5 or 10 min. Minute ventilation was held constant to represent the worst case scenario.

RESULTS

From baseline PaCO2 of 41.8 +/- 2.3 mm Hg, PaCO2 peaked at 68.3 +/- 8.6 (P < 0.02) and 92.9 +/- 10.7 (P < 0.01) mm Hg for the 6- and 12-L volumes, respectively, 20 to 25 minutes following insufflation. From baseline arterial pH of 7.40 +/- 0.02, respective nadirs of pH were 7.21 +/- 0.06 (P < 0.02) and 7.08 +/- 0.05 (P < 0.01). PaCO2 and arterial pH took approximately 100 minutes to return to baseline after insufflation with both 6 and 12 L volumes.

CONCLUSIONS

When minute ventilation is fixed, subcutaneous CO2 insufflation causes increased PaCO2 and decreased pH that may persist for a prolonged period of time. Therefore, patients with subcutaneous emphysema after laparoscopy should be observed in postanesthetic recovery until PaCO2 and pH approach baseline.

Respiratory mechanics and arterial blood gases during and after laparoscopic cholecystectomy

PURPOSE

The purpose of this study was to assess the effects of increased intra-abdominal pressure due to CO2 insufflation on the mechanical characteristics of the respiratory system and arterial blood gases during and after laparoscopic cholecystectomy.

METHODS

Respiratory mechanics and arterial blood gases were examined in 12 patients undergoing laparoscopic cholecystectomy with CO2 insufflation. Respiratory mechanics were continuously monitored with in-line spirometry. In the recovery room, PaCO2 was measured in this group at 30 min and compared with PaCO2s in 23 patients who had undergone open cholecystectomy retrospectively, to evaluate the effects of insufflation on CO2 elimination.

RESULTS

Minute ventilation was decreased by about 500 ml.min-1 during abdominal insufflation. Dynamic lung compliance decreased from 49.6 +/- 4.7 to 30.7 +/- 2.3 (mean +/- SEM) ml.cmH2O-1 with abdominal insufflation (P < 0.005), and returned to 45.1 +/- 3.1 after the release of pneumoperitoneum. Peak inspiratory pressure increased from 15.9 +/- 0.9 to 18.9 +/- 1.0 cmH2O with abdominal insufflation (P < 0.05). Arterial blood gas determinations indicated a decrease in arterial pH, with CO2 retention during insufflation and in the recovery room (P < 0.05). PaCO2 of the laparoscopic patients was higher than that of the open patients in the recovery room.

CONCLUSION

The results indicate that respiratory acidosis was caused during CO2 insufflation for laparoscopic cholecystectomy, that was due to (1) decreased compliance, (2) increased CO2 load and (3) insufficient ventilation. Accumulated CO2 during laparoscopic cholecystectomy increased PaCO2 level in the recovery room.

Complications of laparoscopy and thoracoscopy

Laparoscopy was first performed at the turn of the century, but it was not until the introduction of laparoscopic cholecystectomy that the procedure became widely adopted by general surgeons. Since then, traditional open procedures, including cholecystectomy, exploratory laparotomy, colectomy, hernia repair, and appendectomy, are being widely performed laparoscopically. The advantages of laparoscopic surgery, including less postoperative pain due to smaller surgical incisions, shorter hospital stay, quicker return to preoperative activity, and superior cosmesis, resulted in widespread popularity with both surgeons and patients. In certain situations, the traditional method may be superior to the laparoscopic approach, as may be the case with laparoscopic hernia repair. It is difficult to justify converting a local, extraperitoneal, 45-minute, outpatient inguinal hernia repair in a virgin groin into a general anesthetic, transperitoneal, 2-hour plus, possibly inpatient laparoscopic procedure with the implantation of mesh. However, data may indicate that this operation does indeed have benefits. We must, therefore, carefully study such new operations. With the advent of a new surgical procedure, both surgeons and anesthesiologists must be familiar with the various complications unique to this technique. If recognized early, potentially life-threatening complications, including gas embolization and tension pneumothorax, can be corrected.

Laparoscopic surgery--anesthetic implications

Laparoscopic cholecystectomy is a relatively new surgical procedure which is enjoying ever-increasing popularity and presenting new anesthetic challenges. The advantages of shorter hospital stay and more rapid return to normal activities are combined with less pain associated with the small limited incisions and less postoperative ileus compared with the traditional open cholecystectomy. The efficacy of laparoscopic appendectomy and hemicolectomy has been recently evaluated. However, there have been no prospective randomized studies to date comparing laparoscopic with traditional laparotomy techniques. The physiological effects of prolonged pneumoperitoneum and the longer duration of surgery with the laparoscopic techniques are of concern. The application of laparoscopic inguinal hernia repair may be limited because, unlike traditional surgical hepair, general anesthesia is required and concerns have been expressed about the duration of surgery and the possibility of hernia recurrence. Notwithstanding case reports and series describing successful diaphragmatic and hiatus hernia repair using a laparoscopic surgical technique, the frequently encountered complications of cervical surgical emphysema, pneumothorax, and pneumomediastinum, attributed to passage of insufflating gas through weak points or defects in the diaphragm, must be of major concern. Anesthesiologists must maintain a high index of suspicion for these potential complication and must undertake appropriate monitoring. If there is clinical evidence of a tension pneumothorax, immediate chest tube decompression is indicated. Intraoperative complications of laparoscopic surgery are mostly due to traumatic injuries sustained during blind trocar insertion and physiological changes associated with patient positioning and pneumoperitoneum creation. The choice of anesthetic technique for upper abdominal laparoscopic procedures is most frequently limited to general anesthesia. Controlled ventilation avoids hypercarbia, and an anesthetic technique incorporating antiemetics and nonsteroidal anti-inflammatory agents has reduced postoperative nausea and vomiting following laparoscopic cholecystectomy. The use of nitrous oxide during laparoscopic procedures remains controversial. Laparoscopic cholecystectomy is a major advance in the management of patients with symptomatic gall-bladder disease. However, in the present era of cost containment, older and sicker patients may present for this procedure on the day of surgery without adequate preoperative evaluation. Anesthesiologists should thus be prepared to recommend deflation of the pneumoperitoneum and possibly conversion to an open procedure if hemodynamic, oxygenation, or ventilation difficulties arise during the procedure.

Gallbladder and gallstone removal, open versus closed laparoscopy, and pneumoperitoneum

Surgeons need to be aware of the various options available to remove enlarged gallbladders or gallstones lost during laparoscopic cholecystectomy. Every attempt should be made to recover stones that have escaped from a ruptured gallbladder during laparoscopic cholecystectomy, short of converting to laparotomy. Initial access to the peritoneal cavity can be safely accomplished using either a closed or an open technique. Ideally, surgeons should become facile with both procedures. Carbon dioxide (CO2) gas has emerged as the most practical agent for pneumoperitoneum during laparoscopic cholecystectomy. Surgeons should be knowledgeable about the physiologic and pathologic effects of CO2 gas.

Anaesthesia for laparoscopic general surgery

Laparoscopic surgery minimises postoperative morbidity. Patient benefits include reduction in postoperative pain, better cosmetic result and quicker return to normal activities. Hospital stay is shortened resulting in a reduction in overall medical cost. The intraoperative requirements of laparoscopic surgery however can lead to serious physiological changes and complications. While there is a low but definite perioperative mortality rate associated with minor gynaecologic laparoscopic procedures, laparoscopic general surgical procedures are performed on older patients and patients with acute surgical conditions and are likely to be associated with a higher incidence of perioperative complications. The major problems during laparoscopic surgery are related to the cardiopulmonary effects of pneumoperitoneum, systemic carbon dioxide absorption, extraperitoneal gas insufflation, venous gas embolism and unintentional injuries to intra-abdominal structures. An appraisal of the potential problems is essential for optimal anaesthetic care of patients undergoing laparoscopic surgery. Appropriate anaesthetic techniques and monitoring facilitate surgery and allow early detection and reduction of complications. The need for rapid recovery and short hospital stay impose additional demands on the anaesthetist for skillful practice.