J Tikellis | PubMed Health

PubMed1986

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.

Animals↗

PubMed1985

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.

Adult↗