Length of surgery and pressure ulcers risk in cardiovascular surgical patients: a dose-response meta-analysis

The aim of this study was to assess the relationship between length of surgery (LOS) and pressure ulcer (PU) risk in cardiovascular surgery patients. PubMed and Web of Science were systematically searched. We compared LOS difference between PU (+) group and PU (-) group. We also examined the dose-response effect of this relationship. The mean LOS in the PU(+) groups ranged from 252·5 to 335·7 minutes, compared with 233·0 to 298·3 minutes in PU(-) groups. The LOS was higher in PU(+) groups compared with PU(-) groups [weighted mean difference (WMD) = 36·081 minutes; 95% CI: 21·640-50·522 minutes; Z = 4·90, P = 0·000]. The funnel plot showed no publication bias. A significant dose-response association was also found between the LOS and the risk of surgery-related pressure ulcers (SRPU, model χ²  = 9·29, P = 0·000). In the linear model, the PU OR was 1·296 (95% CI 1·097-1·531) for a 60-minute increase in the LOS intervals and 13·344 (95% CI 2·521-70·636) for a 600-minute increase. In a spline model, the OR of PU increased almost linearly along with the LOS. Our meta-analysis indicated that LOS was an important risk factor for pressure ulcers in cardiovascular surgical patients.