Intraperitoneal lavage and kanamycin for the contaminated abdomen

Aminoglycoside peritoneal lavage: lack of efficacy in experimental fecal peritonitis

The utility of an adjunctive aminoglycoside lavage in the prevention of intra-abdominal abscesses utilizing an experimental rodent model was studied. Peritonitis was created in 115 rats by the intra-abdominal placement of gelatin capsules containing a barium-sulfate, human stool mixture. Four hours later, the animals were re-explored and lavaged with 30 ml/kg of sterile saline. Following the lavage, they were randomized to receive 15 ml/kg of either a 0.2% gentamicin or a normal saline lavage. The animals were then treated with intramuscular gentamicin-clindamycin or saline placebo for nine days. There was no difference in the number of abscesses between the groups receiving systemic antibiotics. The addition of gentamicin to a peritoneal lavage did not decrease the incidence of intra-abdominal infection in animals receiving effective systemic antibiotics.

Antibiotic irrigations. A plea for controlled clinical trials

Although the medical literature describes the perioperative use of antibiotic irrigations in abdominal, pelvic, orthopedic and vascular surgery, the lack of well-designed and executed, controlled clinical studies often precludes a definitive assessment of the value of this technique. Future randomized, double-blind, controlled clinical trials are required to establish its merit. In this age of cost consciousness, lavages with antibiotic solutions cannot at present be regarded as conventional medical therapy.

Amikacin concentrations in serum following intraoperative irrigation of the pleura and peritoneum

Serum concentrations of amikacin following operative wound irrigation were studied in 17 patients having laporatomy and in eight patients having thoracotomy. Irrigation was done with 500 mg of amikacin in 200 ml of saline. The irrigant was reaspirated after 3 minutes. Measurement of amikacin in the irrigant allowed calculation of the retained dose. Serum levels were measured before surgery, and at 30 minutes, 60 minutes, 6 hours, and 12 hours following irrigation. Amikacin was assayed by a microbiological technique. The retained dose after peritoneal irrigation was 350 +/- 128 mg, and after pleural irrigation was 100 +/- 79 mg. The average maximum serum level in the peritoneal irrigation group was 9.4 +/- 6.7 gm/ml; in the thoracotomy group it was 3.5 +/- 1.7. Fourteen of the 17 laparotomy patients but only one of the eight thoracotomy patients had measurable plasma levels at 6 hours. Plasma half-life in the laparotomy group was 2.81 +/- 1.34 hours, and in the thoracotomy group 1.53 +/- 0.83 hours. Interoperative amikacin irrigation, even with immediate aspiration, results in significant absorption in both thoracotomy and laporatomy patients. There was less absorption and a shorter serum half-life in the thoracotomy patients.

The adjuvant effect of peritoneal fluid in experimental peritonitis. Mechanism and clinical implications

At laparotomy, many surgeons routinely instill crystalloid solutions into the peritoneal cavity, presumably to dilute out necrotic debris, bacteria, and adjuvant substances which foster bacterial growth. We examined the effect on mortality, bacterial growth, clearance, and phagocytosis of various volumes of saline instilled into the peritoneal cavity of rats during Escherichia coli peritonitis. Minimal intraperitoneal bacterial growth was seen after the introduction of a nonlethal inoculum of viable E. coli in 1 ml of saline, while administration of an identical inoculum in 30 ml of saline intraperitoneally (i.p.) led to increased 48-hour mortality (p less than 0.01), and associated rapid bacterial proliferation (p less than 0.01). Clearance of nonviable radiolabelled E. coli from the peritoneal cavity was delayed, bacterial association with host peritoneal leukocytes was decreased, and blood uptake of radiolabelled bacteria was diminished in animals receiving 30 ml of saline i.p., compared to controls which received the identical inoculum in 1 ml of saline i.p. The clinical relevance of these studies is manifold: (1) they provide a possible explanation why patients with ascites due to cirrhosis or the nephrotic syndrome, or those patients undergoing peritoneal dialysis are more susceptible to primary and secondary bacterial peritonitis, possibly on the basis of impaired peritoneal clearance or diminished phagocytosis and, (2) although irrigation of the peritoneal cavity with crystalloid solution would seem prudent during laparotomy, these solutions must be removed prior to closure to prevent interference with normal peritoneal host defense mechanisms.

[Therapy of purulent peritonitis. Documentation of 78 cases and experience with taurolin (author's transl)]

From three different surgical departments 78 patients with purulent peritonitis are analyzed according to cause, origin, and extent of peritonitis. Operative therapy is presented. As additional antibacterial therapy the new chemotherapeutic agent, Taurolin, with antiendotoxin-effect is used. The postoperative course (temperature exceeding 38 degrees C, secondary wound healing, day of discharge, and serious complications) is correlated with pre- and intraoperative parameters; for instance, 1. postoperative fever occurs in one half of the patients, more frequently following perforation of stomach and duodenum; 2. every second patient shows secondary wound healing, this happens even more often in peritonitis arising from biliary disease or appendicitis; 3. in 29.5% of the patients serious complications arise, especially in patients with peritonitis originating in stomach, small intestine or large bowel; 4. overall mortality of 11.5% is surpassed in patients with peritonitis originating from small intestine or large bowel. The so-called peritonitis-index (calculated on the basis of pre- and intraoperative factors) shows a significant difference between survivors and patients dying during the postoperative course. In 80% of the 78 patients with purulent peritonitis taurolin was effective as a substitute for the usual antibiotics.

Clinical pharmacology of intravenous and intraperitoneal aminoglycoside antibiotics in the prevention of wound infections

Seventeen patients had intraoperative peritoneal lavage with a solution containing one gram of kanamycin in 200 ml of 0.9% NaCl. The solution was removed by suction at two or five minutes. Venous blood samples were obtained at 15 minute intervals for two hours following lavage. Despite diligent attempts, an average of only 60% of the solution was recovered by suction. The peak concentration of kanamycin in serum correlated directly with the kanamycin dose (p less than 0.025). In six patients lavaged for five minutes, peak absorption occurred at 15 minutes with serum concentrations of 20.3 +/- 2.0 microgram/ml. In five patients lavaged for two minutes insignificantly (p greater than 0.1) lower peak serum concentrations (15.3 +/- 1.8 microgram/ml) occurred at 15 minutes. Six additional patients had peak kanamycin serum concentrations which occurred at 75 minutes and reached 23.2 and 24.0 microgram/ml in two patients. In three patients who received intravenous gentamicin prior to surgery, nine paired serum and peritoneal fluid samples obtained during three hours preceding lavage showed no significant differences in gentamicin concentrations (p less than 0.5). These pharmacokinetic data demonstrate the penetration of parenterally administered aminoglycosides into intraoperative peritoneal fluid. Kanamycin lavage for wound prophylaxis should be used cautiously and should be abandoned in patients who have renal impairment where prolonged toxic serum concentrations could develop.