OBJECTIVETo investigate the influence of changes in perioperative antibiotic prophylaxis (PAP) duration in colorectal surgery on surgical site infection (SSI).

METHODSThe data on PAP in April and October between 2011 and 2013 was collected from tertiary and secondary hospitals in Shanghai. Prevalence of SSI rates over the same period was compared.

RESULTSA total of 2 465 cases of colorectal surgeries were studied over the three-year period, including 1 784 cases in tertiary hospitals and 681 cases in secondary hospitals. In 940 surgical operations, PAP duration were within 72 hours, accounting for 38.1% of all cases. 48.0% of the operations in 2013 had a PAP within 72 hours, which is significantly higher than that of 20.8% seen in 2011 (χ(2) = 129.986, P = 0.000). In 2013, 53.5% of the all procedures in tertiary hospitals had PAP ≤ 72 hours, compared with 35.5% in secondary hospitals over the same period (χ(2) = 22.714, P = 0.000). Combined uses of nitroimidazoles, with an effect of anti-anaerobic, were used much more commonly in tertiary (76.0%) than in secondary hospitals (41.4%) (χ(2) = 267.820, P = 0.000). The usage of cephamycin were higher in secondary (20.6%) than in tertiary hospitals (4.7%) (χ(2) = 149.865, P = 0.000). According to the investigations by SICC on prevalence of healthcare-associated infections between 2011 and 2013, colorectal surgeries have an average SSI rate of 2.0%. Stratified data showed that the rate of PAP ≤ 72 hours increase from 23.6% in 2011 to 45.8% in 2013 over the same period. However, the SSI rate did not show a significant change (1.9% in 2011, 1.7% in 2013). There was no linearly dependent between the two rates (r = 0.015, P = 0.990).

CONCLUSIONSThe proportion of rational PAP of colorectal surgeries in Shanghai has increased. Perioperative antibiotic prophylaxis duration decreased, while SSI rates over the same period did not increase.