Wound infections in appendicitis: effective prophylaxis

Gangrenous and perforated appendicitis: a meta-analytic study of 2532 patients indicates that the incision should be closed primarily

BACKGROUND

Surgical incisions after appendectomy for complicated (gangrenous or perforated) acute appendicitis are often managed with delayed closure (DC) rather than primary closure (PC). This study synthesizes the results of other studies in the surgical literature and supports the routine use of PC.

METHODS

Studies dealing with complicated appendicitis were reviewed to assess the results of PC in comparison with DC. The rate of incision (wound) infection in groups of patients managed by PC and DC were compared with the use of a statistical technique that defined the probability of expected results by incorporating data derived from all of the various study groups.

RESULTS

Of the 2532 patients who had been treated for complicated appendicitis and who were assessed, 1724 patients underwent PC and 808 patients underwent DC. The rate of incision infection was 4.7% and 4.6% in the PC and DC groups, respectively. With a 95% confidence interval, there was no demonstrable difference between the 2 types of operative site management (P < .01).

CONCLUSIONS

PC of the skin and subcutaneous tissue after appendectomy for gangrenous or perforated appendicitis, combined with the use of antibiotic therapy in the perioperative period, is not associated with an increased risk of incision infection when compared with DC.

Leg wound infections associated with coronary revascularization

BACKGROUND

Wound infections after saphenous vein harvest for coronary revascularization are common but they are infrequently examined. The aim of the present study was to investigate the risk factors for infection and the possible beneficial effects of saline lavage.

METHODS

From April 1996 to July 1996, 152 consecutive patients who underwent saphenous vein harvest for coronary artery bypass graft were recruited. Factors that may influence infection rates were analysed.

RESULTS

A total of 22 of the 125 (18%) patients included in the present study developed a wound infection. The length of the wound was the only variable found to have a statistically significant association with wound infection. In the analysis of patients with multiple leg wounds, the development of infection correlated with the absence of mechanical wash-out.

CONCLUSION

The use of saline lavage may prevent wound infections by diluting the bacterial population prior to closure. The use of antiseptic or antibiotic lavage may offer an additional benefit.

Laparoscopic versus open appendicectomy for suspected appendicitis: a prospective study

Despite recent advances in minimally invasive surgery, laparoscopic appendicectomy has been questioned as a feasible method of treating patients with suspected appendicitis because open appendicectomy carries few risks and complications. Between February 1992 and January 1993 a non-randomized prospective study comparing open and laparoscopic appendicectomy was designed to assess differences in postoperative morbidity, pain, inpatient hospital stay and a return to normal lifestyle. One hundred and sixty-seven patients with suspected clinical appendicitis were assigned to open (n = 74) or laparoscopic (n = 93) appendicectomy. Six patients were excluded due to the presence of other significant pathology such that the appendix was not removed. Eighty-seven patients underwent attempted laparoscopic appendicectomy, of which 81 were completed. The diagnosis of appendicitis was confirmed histologically in 63.5% of patients undergoing open appendicectomy and 63% of patients undergoing laparoscopic appendicectomy. There were no significant differences in anaesthetic times, postoperative morbidity and analgesic requirements. There was a significant reduction in both postoperative inpatient stay (P < 0.0001) and time taken to return to work or normal activities (P < 0.0001) for the laparoscopic group. The use of laparoscopy for patients with suspected appendicitis aids definitive diagnosis and should reduce the negative appendicectomy rate to an acceptable figure. The results suggest that laparoscopic appendicectomy is safe and offers advantages over open appendicectomy in the management of patients with suspected appendicitis.

Prophylactic antibiotic use in four Dublin teaching hospitals

A retrospective study of 266 surgical patients revealed that 55% received antibiotics. Of these, 71% had prophylactic and 29% therapeutic courses. Twenty-five per cent of prophylactic courses were started post-operatively, 65% were continued for more than 24 hours, 28% were administered by an inappropriate route and 10% were started more than two hours pre-operatively. Of all courses of antibiotics ordered, 67% had no record of intended duration on the prescription. In 4% of courses the surgeon's orders were not followed. This study demonstrates widespread suboptimal use of antibiotic prophylaxis in a variety of surgical specialties.

Preventing wound infection after appendicectomy: a review

An exponential increase in the number of published prospective studies reflects both a continuing interest in, and a lack of consensus on, the optimal prophylaxis of wound sepsis after appendicectomy. Review of the literature over the last 25 years leads us to emphasize both the importance of adequate study size and of stratification of the severity of the sepsis found at operation. For critical comparison of prophylactic regimens the high percentage of wound infections disclosed after discharge from hospital must be taken into account. Antibiotics reduce the frequency of wound sepsis and although low wound sepsis rates have been reported with systemic antibiotics active against only anaerobes, the cumulative evidence favours a spectrum of antibacterial activity against both aerobic and anaerobic organisms. Topical antiseptics have no significant effect but topical antibiotics are beneficial. Wide variations in outcome for similar antibiotic regimens reflect the importance of technical factors in determining the frequency of wound sepsis.

Influence of surgeons' experience on postoperative sepsis

A prospective study was performed on 635 patients with appendicitis operated on by 7 trainees and 119 patients operated on by 6 senior surgeons with more than 8 years of surgical experience. In patients with normal appendices, postoperative sepsis was extremely low. For early and late appendicitis, the infection rates of the trainees decreased as experiences accumulated, but they were still higher than that of the senior surgeons. The difference in infection rates in acute appendicitis did not reach statistical significance between any of the training stages and between the various stages and the rate of the senior surgeons. The differences in infection rates in late appendicitis between stage 1 and stage 3 was significant, as was the difference in infection rates between stage 1 and the infection rate of the senior surgeons. Therefore, we have concluded that overall, the limited experience of trainees is related to the rate of postoperative sepsis in late appendicitis, although the infection rates of individual trainees vary a lot.

Appendicitis in children: a systematic approach for a low incidence of complications

Four hundred fourteen appendectomies in children have been described. Acute nonperforated appendicitis was seen in 57.1 percent of the patients and perforated appendicitis in 18.6 percent. A histologically normal appendix was seen in 14.3 percent of the patients. In 31 of these patients, other pathologic abnormalities were found to account for the symptoms, thus the number of negative explorations was reduced to 7 percent. The average length of hospitalization was 5.3 days for patients with acute nonperforated appendicitis and 7.3 days for patients with perforated appendicitis. A protocol was followed which consisted of fluid resuscitation, preoperative and postoperative administration of antibiotics, and surgical exploration with appendectomy in all patients. No interval appendectomies were performed. The peritoneal cavity was not irrigated and the use of drains was avoided as much as possible. All wounds were closed primarily without wound drains. Topical cefamandole powder was used in all cases. Aerobic and anaerobic culture specimens were obtained in all cases from the peritoneal cavity and appendiceal stump. Twenty-eight different organisms were recovered, B. fragilis being the most common followed by E. coli. Excellent results were obtained without mortality and a less than 1 percent complication rate. There was a shorter period of hospitalization for patients with perforated appendicitis and a shorter period of antibiotic treatment.

Perioperative prophylaxis with sulbactam and ampicillin compared with metronidazole and cefotaxime in the prevention of wound infection in children undergoing appendectomy

Sulbactam is a beta-lactamase inhibitor, which when administered with ampicillin, increases the latter agents antibacterial activity against beta-lactamase producing organisms. One hundred children between the ages of 5 and 14 undergoing emergency appendectomy were entered into a prospective randomized trial comparing sulbactam and ampicillin (SA) with metronidazole and cefotaxime (MC) as prophylaxis against postoperative wound infection. Patients in whom the appendix was perforated or gangrenous received a 72-hour course of antibiotics, others received a single dose only. The overall wound infection rate was 8% (14% in patients with perforation or gangrene and 4% in those without). There was no difference in infection rate between the two antibiotic groups; there were three wound infections and one subphrenic abscess in patients receiving SA and four wound infections in patients receiving MC. SA, therefore, appears to be a suitable antibiotic combination for use as prophylaxis in appendicitis in children.

Metronidazole and Augmentin in the prevention of sepsis after appendicectomy

Two hundred and fifty patients were admitted to a prospective randomized trial to compare the efficacy of Augmentin with metronidazole in the prevention of sepsis after appendicectomy. Pre-operatively they received either 500 mg metronidazole or 1.2g Augmentin intravenously. Those patients with gangrenous or perforated appendices received eight additional doses of the trial drug at 8 hourly intervals. Overall there were 13 wound infections in the Augmentin group (11 per cent) and 21 in the metronidazole group (18 per cent). The 90 per cent confidence limits for the overall 7 per cent difference in infection rates were +/- 8.5 per cent. There were high rates of wound infection in the gangrenous group (Augmentin 8 per cent versus metronidazole 19 per cent) and especially in the perforated group (Augmentin 33 per cent versus metronidazole 63 per cent). There was no statistically significant difference between the infection rates with the two antibiotics but our study suggests that Augmentin, which is active against both aerobes and anaerobes, may be more effective than metronidazole in reducing wound sepsis after appendicectomy.