Randomized multicentre trial of oral bowel preparation and antimicrobials for elective colorectal operations

Abstract

A study of 120 patients undergoing elective colorectal operations has investigated the effect of adding oral neomycin and metronidazole to bowel preparation in a double-blind randomized controlled trial. Comparisons have also been made between a standard mechanical preparation and the use of an elemental diet. The addition of neomycin and metronidazole to bowel preparation significantly reduced the rate of wound sepsis (P less than 0.01), septicaemia (P less than 0.02) and anastomotic dehiscence (P less than 0.02); anaerobic infections were abolished and there was a significant reduction in the incidence of aerobic Gram-negative infections. Elemental diets were shown to have no advantage over mechanical preparation.

Importance of Adding Neomycin to Metronidazole for Bowel Preparation1

“…On the other hand, results of two independent trials in Britain have shown a significant reduction in postoperative sepsis when oral metronidazole was used with kanamycin (Goldring et al 1975) or neomycin (Matheson et al 1978). The present findings support these studies.…”

“…The aim of oral antimicrobial therapy is to reduce the bacterial inoculum from within the bowel by lowering the counts of the principal pathogenic bacteria in the faeces rather than providing serum antibiotic levels . It is not surprising, therefore, to find that in the present study the regime of oral metronidazole and placebo neomycin, which has no influence on the faecal flora, was associated with an incidence of sepsis which was similar to that in a control group in a previous trial undertaken in the same hospital (Matheson et al 1978). Comparable results have been reported in a trial to compare the combination of metronidazole and phthalysulphathiazole with phthalysulphathiazole alone (Taylor et al 1979).There was only a reduction in sepsis when both agents were used in combination.…”

“…Until recently, neomycin or phthalylsulphathiazole have been the mainstay of antimicrobial prophylaxis because of their influence on coliform organisms in the bowel lumen (Nichols et al 1972). With increasing recognition of the importance of anaerobic bacteria in the pathogenesis of sepsis after large bowel operations (Moore et al 1969), it has been recommended that agents such as tetracycline, erythromycin and metronidazole be used-in combination with neomycin (Clarke et al 1977, Matheson et al 1978, Washington et al 1974. It has even been suggested that antianaerobic drugs such as metronidazole or lincomycin are effective on their own without the need for aminoglycosides such as neomycin, kanamycin or gentamicin (Leigh 1975, Willis et al 1977.…”

Preoperative mechanical bowel preparation in elective colorectal surgery: an update of systematic review of the literature and meta-analysis

“…Seven trials were excluded since the first publication, due to several reasons: series of patients 38 ; no control group 39,40 ; data verification in congress 13 ; retrospective study 41 ; case-control study 42 ; study evaluating antimicrobial substances 7 . Four authors of the trials included in our review 14,18,20,24 answered our correspondence and sent data that allowed to stratify anastomoses as colic and low colorectal.…”

“…Since then, several methods of mechanical colon cleansing have been used, via anterograde and/or retrograde routes, which indicates that, so far, no standard mechanical bowel preparation method has been established. Based on some studies [6][7][8] , where the authors clinically investigated the exclusively antibiotic prophylaxis administration in elective colorectal surgery, the importance of stool in the anastomotic area started to be questioned. Reports of emergency surgeries [9][10][11][12] also aroused suspicions regarding the need for mechanical bowel preparation in elective colorectal surgery.…”