Aprotinin: role in minimizing perioperative blood loss

Pancreatic digestive enzyme blockade in the intestine increases survival after experimental shock

Shock, sepsis, and multiorgan failure are associated with inflammation, morbidity, and high mortality. The underlying pathophysiological mechanism is unknown, but evidence suggests that pancreatic enzymes in the intestinal lumen autodigest the intestine and generate systemic inflammation. Blocking these enzymes in the intestine reduces inflammation and multiorgan dysfunction. We investigated whether enzymatic blockade also reduces mortality after shock. Three rat shock models were used here: hemorrhagic shock, peritonitis shock induced by placement of cecal material into the peritoneum, and endotoxin shock. One hour after initiation of hemorrhagic, peritonitis, or endotoxin shock, animals were administered one of three different pancreatic enzyme inhibitors--6-amidino-2-naphtyl p-guanidinobenzoate dimethanesulfate, tranexamic acid, or aprotinin--into the lumen of the small intestine. In all forms of shock, blockade of digestive proteases with protease inhibitor attenuated entry of digestive enzymes into the wall of the intestine and subsequent autodigestion and morphological damage to the intestine, lung, and heart. Animals treated with protease inhibitors also survived in larger numbers than untreated controls over a period of 12 weeks. Surviving animals recovered completely and returned to normal weight within 14 days after shock. The results suggest that the active and concentrated digestive enzymes in the lumen of the intestine play a central role in shock and multiorgan failure, which can be treated with protease inhibitors that are currently available for use in the clinic.

Aprotinin may decrease blood loss in complex adult spinal deformity surgery, but it may also increase the risk of acute renal failure

STUDY DESIGN

Matched cohort comparison.

OBJECTIVE

This study examines the potential for aprotinin to conserve blood in adults undergoing long thoracolumbar deformity procedures and characterizes patients at risk for acute renal failure.

SUMMARY OF BACKGROUND DATA

Aprotinin has been shown to reduce intraoperative blood loss and reduce transfusion requirement in pediatric spine and cardiac surgery populations. Previous literature (before 2006) has not reported acute renal failure as a potential complication. This study was designed to examine the efficacy of aprotinin in reducing operative blood loss following long spinal arthrodesis in adult spinal deformity patients and to analyze complications.

METHODS

Adult spinal deformity patients undergoing long spinal arthrodesis at 1 institution between 2001 and 2005 were analyzed. Patients were matched according to age and type of procedure performed. Forty patients received high-dose aprotinin (Group A) intraoperatively, and 41 patients matched as controls (Group NA) received no aprotinin. Outcome variables included intraoperative blood loss, intraoperative transfusion requirement, early postoperative blood loss and transfusion requirement, and postoperative complications.

RESULTS

Average blood loss for Group A was 906 mL and 1.3 L for Group NA. The difference was statistically significant with a P < 0.05. Complications seen in Group A included 4 cases of acute renal failure requiring dialysis and 1 deep venous thrombosis. In Group NA, there was only 1 case of acute renal failure (presumed to be secondary to inadvertent gentamycin overdose) and 1 case of pulmonary embolus. The 4 Group A patients with acute renal failure were female, 61 to 73 years of age, with various comorbidities. All required inpatient hemodialysis. Three averaged 2 months of continued outpatient dialysis before resolution of renal compromise while 1 patient is on chronic dialysis.

CONCLUSION

In long spinal arthrodesis for complex adult spinal deformity surgery, aprotinin does reduce intraoperative blood loss, but may increase the risk of acute renal failure, especially in women over the age of 60.