The impact of wound age on the infection rate of simple lacerations repaired in the emergency department.

Background: The influence of wound age on the risk of infection in simple lacerations repaired in the emergency department (ED) has not been well studied. It has traditionally been taught that there is a "golden period" beyond which lacerations are at higher risk of infection and therefore should not be closed primarily. The proposed cutoff for this golden period has been highly variable (3-24h in surgical textbooks). Our objective is to answer the following research question: are wounds closed via primary repair after the golden period at increased risk for infection?

Methods: We searched MEDLINE, EMBASE, and other databases as well as bibliographies of relevant articles. We included studies that enrolled ED patients with lacerations repaired by primary closure. Exclusion: (1) delayed primary repair or secondary closure, (2) wounds requiring intra-operative repair, skin graft, drains, or extensive debridement, and (3) grossly contaminated or infected at presentation. We compared the outcome of wound infection in two groups of early versus delayed presentations (based on the cut-offs selected by the original articles). We used "Grading of Recommendations Assessment, Development and Evaluation" (GRADE) criteria to assess the quality of the included trials.

Results: 418 studies were identified. Four trials enrolling 3724 patients in aggregate met our inclusion/exclusion criteria. The overall quality of evidence was low. The infection rate in the wounds that presented with delay ranged from 1.4% to 32%. One study with the smallest sample size (only 19 delayed wounds), which only enrolled lacerations to hand and forearm, showed higher rate of infection in patients with delayed (older than 12h) wounds (relative risk of infection: 4.8, 95% confidence interval, 1.9-12.0). The infection rate in delayed wound groups in the remaining three studies was not significantly different.

Conclusion: The existing evidence does not support the existence of a golden period nor does it support the role of wound age on infection rate in simple lacerations.