Octreotide in the treatment of thoracic duct injuries.

Anecdotal reports support the use of octreotide in the treatment of traumatic thoracic duct injuries and chylothorax, but no prospective studies have proved its efficacy. We evaluated the effects of octreotide in treating thoracic duct transection in a canine model. Eight mongrel dogs (27.8+/-5.1 kg) were fed one pint of 10.5 per cent milkfat 2 hours before operation. Through a left supraclavicular neck incision, the thoracic duct was identified and transected, producing free flow of chyle. A quarter-inch drain was tunneled subcutaneously from the wound and attached to closed suction. After wound closure dogs were randomized to a control group (n = 4) receiving sham injections of saline subcutaneously three times per day, or a treatment group (n = 4) given 3 microg/kg octreotide three times per day. Postoperatively all dogs were fed a standard low-fat (5-7%) crude fat diet. Drain output was measured each day, and on odd-numbered postoperative days the drainage was analyzed for cholesterol, triglycerides, albumin, and total protein. Fistula closure was defined as drainage <10 ml/24-hour period. Treated dogs achieved fistula closure significantly faster than controls: 3.5+/-1.3 days versus 7.8+/-1.0 days (P = 0.0037). Whereas equivalent amounts of drainage occurred on the day of surgery and on postoperative day one in both groups, by postoperative day 2 the treatment group had significantly less drainage over 24 hours: 63+/-69 ml versus 195+/-79 ml (P = 0.046); this significant difference persisted through postoperative day 5 when drainage began to decrease in the control group. No significant differences between groups were seen in levels of cholesterol, triglycerides, albumin, or protein in the drainage at any time point. We conclude that octreotide is effective in treating thoracic duct injury, leading to an early decrease in drainage and early fistula closure. The mechanism for this effect remains to be clarified.

Cell washing versus immediate reinfusion of intraoperatively shed blood during abdominal aortic aneurysm repair.

Significant hematologic changes are known to occur following intraoperative autotransfusion of shed blood, but the clinical importance of cell washing prior to reinfusion has not been substantiated. To evaluate these changes and their relationship to the use of blood bank products and postoperative morbidity, 26 patients undergoing elective abdominal aortic aneurysm repair were prospectively randomized to reinfusion with washed shed blood or to the use of a collection system in which filtered, but unwashed, whole blood was reinfused intraoperatively. Each patient was evaluated with respect to standard metabolic and hematologic laboratory parameters preoperatively, immediately postoperatively, and 12 to 18 hours postoperatively. Patient demographic data were similar for both groups. Perioperative survival was 100% for both groups. Total blood loss and blood volume autotransfused were significantly greater in the unwashed cell group compared with the washed cell group (p = 0.00014 and p = 0.00011, respectively). Hemoglobin, fibrinogen, prothrombin time, and partial thromboplastin time levels were not significantly different between the two groups at any time perioperatively; fibrin split product and d-dimer levels were significantly higher in the unwashed cell group postoperatively (p = 0.016 and p < 0.001, respectively). Serum free hemoglobin levels were significantly higher in the immediate postoperative period in the unwashed cell group compared with the washed cell group (p = 0.0013); by 12 to 18 hours postoperatively, this difference was not significant. Haptoglobin levels were significantly lower in the unwashed cell group at both postoperative times (123 +/- 86 mg/dL versus 41 +/- 50 mg/dL, p = 0.0086; 102 +/- 66 mg/dL versus 24 +/- 36 mg/dL, p = 0.0001); however, there was no perioperative renal failure in either group. Furthermore, homologous blood product use was not significantly different between the two groups, with an average of 1.5 +/- 2.5 units of packed red blood cells given to patients in the unwashed cell group versus 0.8 +/- 1.7 units in the washed cell group (p = 0.419). Overall complications were higher and critical care and total hospital stays were longer in the unwashed cell group but did not result from autotransfusion of unwashed blood. We conclude that the intraoperative reinfusion of unwashed shed blood is safe and effective, causing transient hematologic abnormalities that normalize in the early postoperative period, and is not associated with increased mortality, or hematologic, cardiopulmonary, or renal complications.

Systemic effects of intraoperative autotransfusion.

The hematological effects of autotransfusion have not been well characterized. A canine model was used in which a controlled 2000-ml blood loss was effected into the open peritoneum and replaced either by autotransfusion, using one of two devices, or by homologous transfusion. In each group hematological data were collected before, during, and after the operation. None of the parameters measured showed significant differences between the two autotransfused groups. However, intraoperative values for prothrombin time and activated partial thromboplastin time were significantly prolonged in the autotransfused groups compared with the homologous transfusion group. Fibrinogen levels and platelet counts fell significantly from baseline levels in the intraoperative period, but rose above even baseline levels postoperatively. White blood cell counts remained unchanged intraoperatively, but rose significantly and remained elevated at 24 hours and 1 week. No significant differences exist between the effects produced by the two autotransfusion systems. It is clear that prothrombin time and activated partial thromboplastin time are prolonged intraoperatively in the autotransfusion groups, whereas these parameters are unaffected by homologous transfusion.

Clotting competence of intracavitary blood in trauma victims.

In order to assess more rationally the requirement for anticoagulation during intraoperative autotransfusion, the clotting competence of blood collected from the body cavities of 31 trauma victims entering our emergency department with indications for intraoperative transfusion was assessed. Blood was collected at thoracotomy or laparotomy prior to the institution of any anticoagulant measures and was assessed for clotting competence, the presence of fibrinogen, the presence of soluble fibrin monomere, and the appearance of fibrin degradation products. The prothrombin time, partial thromboplastin time, and thrombin time of this blood were markedly elevated; fibrinogen was absent; soluble fibrin monomer was absent; and fibrin degradation products were markedly elevated. Blood collected from body cavities is then incoagulable, and we suggest that in the autotransfusion of such a product the need for anticoagulation may be reduced.

Autotransfusion of contaminated intraperitoneal blood: an experimental study.

Contamination of blood by bowel contents has been generally assumed as an absolute contraindication to autotransfusion. Since abdominal trauma is frequently accompanied by bowel injury and massive blood loss, a potential major use for autotransfusion has thus been precluded. To test this presumption, autologous blood grossly contaminated with feces was incubated in the peritoneal cavity and then autotransfused in dogs. The animals were hemorrhaged 20, 30, or 40% of their estimated blood volume, producing mild to severe hypovolemic shock. Reinfusion of contaminated blood had little effect on survival with 20 or 30% hemorrhage, but contamination markedly decreased survival with 40% hemorrhage:90% survived without contamination while only 30% survived with contamination. The use of antibiotics in a similar group of dogs subjected to 40% hemorrhage essentially eliminated the risk of autotransfusion: 90% of these dogs survived autotransfusion of contaminated blood.

Autotransfusion of blood contaminated by intestinal contents.

In a series of 183 emergency operations in which intraoperative autotransfusion was used, 14 patients received blood contaminated by intestinal contents. Six of the 14 patients died early in the postoperative period, four of whom had received more than 16 liters of blood. Only two of the eight survivors had received comparable amounts of blood (13 and 17.5 liters). All eight received antibiotics upon admission; four had positive blood cultures within 24 hours of operation. Complications included acute tubular necrosis in three patients and bowel obstruction with intra-abdominal abscess in another. One of the patients with acute tubular necrosis died six weeks later; all others recovered. We believe this procedure may be life-saving in some cases.

Intraoperative autotransfusion: an underutilized technique.

Although interest in intraoperative autotransfusion increased when commercial equipment became available, this technique still is utilized rarely in most hospitals. Our experience began with sporadic use in 1972 and has evolved to regular use at least ten times a month. The machine is operated by a technician, and we heparinize the autotransfusion system (ATS) reservoir. Our series includes 47 patients who had elective vascular operations and 141 who had emergency operations, usually for trauma. In the latter group, seven patients who were autotransfused with blood contaminated by intestinal contents survived near fatal injuries and did not develop complications attributable to the procedure. Morbidity and mortality rates in both groups did not appear to be increased as a result of intraoperative autotransfusion. Controversy over methods of anticoagulation and apprehension about effect on blood are not valid reasons for underutilization of this technique. Although significant administrative commitments are required to implement its use and to treat the coagulopathy that accompanies massive reinfusions, they are justified by the value of intraoperative autotransfusion in most cases in which two or more units of blood would be required ordinarily.