Elective intraoperative intracranial pressure monitoring during laparoscopic cholecystectomy.

The effects of artificial pneumoperitoneum on intracranial pressure have not been clearly defined. Initial animal studies indicate that elevated intra-abdominal pressure might have a deleterious effect on intracranial pressure. We report a case in which intracranial pressure was monitored intraoperatively during laparoscopic cholecystectomy. Intracranial pressure increased abruptly when the peritoneal cavity was insufflated, with the operating table in the Trendelenburg position, and decreased slightly with elevation of the head of the operating table. Initial opening intracranial pressure values were re-established on desufflation of the abdomen. Intracranial pressure monitoring should be considered when planning a laparoscopic procedure on patients with the potential for decreased intracranial compliance.

Surgical prophylaxis for pulmonary embolism.

The trauma patient population is at special risk for fatal pulmonary embolism. We experienced 11 fatalities in one 12-month period. Specific risk factors for both deep venous thrombosis and pulmonary embolism can be identified among trauma patients. The latter usually cannot be offered prophylactic anticoagulation, and the nature of their injuries (e.g., long bone fractures) makes not only bedside surveillance difficult but also precludes use of pneumatic compression, etc. We have developed a protocol for prophylactic inferior vena caval filtration for our trauma patients deemed at particular risk for pulmonary embolism. Since 1986 we have inserted 205 Greenfield filters in 201 patients. Two hundred were inserted prophylactically. There was no mortality, and morbidity was minimal. No patient with a Greenfield filter sustained a fatal pulmonary embolism during this period. Four patients died from pulmonary embolism before vena caval filters could be inserted. We believe that the trauma patient, at risk for pulmonary embolism, should be offered a Greenfield filter prophylactically as soon after hospitalization as logistically possible.

A nonheparinized muscle model for studies of ischemia-reperfusion injury.

An understanding of the basic metabolic, functional, and histologic features of skeletal muscle injury secondary to ischemia and reperfusion has thus far been hampered by the lack of an adequate animal model. We have developed an in vivo isolated skeletal muscle preparation amenable to ischemia-reperfusion studies and the investigation of therapeutic modalities. The model is autoperfused and, most importantly, nonheparinized. The use of a nonheparinized model is essential following the work of Hardaway, recently confirmed by Fry, showing that alterations of flow in the shock state occur when heparin is used, invalidating other models as true replicas of clinical situations. The gracilis muscle in the canine hindlimb and its contralateral control are isolated on their neurovascular pedicles after detachment of fascial boundaries and meticulous ligation of all collateral vascular supply. Prolonged arterial occlusion can be accomplished by clamping proximal and distal to the point of origin of the gracilis artery from the superficial femoral artery. In a similar fashion, occlusion above and below the gracilis vein is effected intermittently to collect venous efluent during reperfusion. Preliminary studies of 100 muscle preparations subjected to 3 or 15 hr of ischemia, followed by 2 hr of reperfusion, demonstrate depression of oxygen utilization of 5% of control values during early reperfusion with improvement to 30% of control values over 2 hr. Contractility, abolished during ischemia, returns to 20% of control values after 2 hr of reperfusion.

Beneficial effects of ethanol on experimental burns.

Alcohol has been demonstrated to produce cutaneous vasodilation. The burn wound is characterized by a compromised microcirculation which is amenable to pharmacologic manipulation to improve the final outcome of the injury. Various agents including heparin, aspirin, nonsteroidal anti-inflammatory agents have been employed to maintain a patent microcirculatory bed. Ethanol has been used in the present study in a murine burn model as a vasodilator administered immediately preburn and post-burn. Preburn administration of ethanol significantly improved the mean burn severity at 48 hr compared to ethanol given post-burn. Ethanol, acting as a vasodilator, improves dermal circulation post-burn and reduces the overall extent of injury.

Reoperation for sepsis.

A retrospective study of 50 patients undergoing reoperation for sepsis was performed to evaluate the ability of commonly available clinical and laboratory tests to predict the findings at reoperation and the outcome after operation. The influence of multiple organ failure on these parameters was also studied. No laboratory finding helped to predict operative findings. Computed tomographic scanning (80% accurate) was the most helpful radiographic procedure. A low total lymphocyte count and a high serum creatinine level both predicted a fatal outcome. No single organ failure or combination predicted a positive reexploration. Infection was found in 75 per cent of patients with multiple organ failure and 79 per cent of patients who did not have this syndrome. Patients having three-organ failure did have a significantly higher mortality. The mortality of a negative reexploration was 18.2 per cent, slightly lower than the 28.2 per cent mortality of patients with a positive exploration. No patient without organ failure died. The authors conclude that laboratory tests are not helpful in predicting the presence of infection on reexploration, that the decision to reoperate is one based primarily on clinical judgment, and that if reoperation is performed before the development of organ failure, the risk associated with a negative exploration is worth taking.