Risk Factors for Infection in Traumatic Lacerations

There have been several studies examining the risk factors of infection in traumatic lacerations. A cross-sectional study by Hollander et al identified 5,521 patients with traumatic lacerations. Of these patients, 194 (3.5%) developed a wound infection. Those patients who developed wound infections had a longer laceration (infected 3.3 cm vs non-infected 2.6 cm, p=0.0001), higher incidence of diabetes (OR 6.74, p=0.006), and presence of foreign body (OR 2.63, p=0.006). Patients with lacerations on the head/neck had a lower risk of infection (OR 0.28, p=<0.0001). Time from injury was not found to be statistically significant in the incidence of wound infection.

A second study by Waseem et al involved 297 patients with traumatic lacerations. In this prospective observational study, only simple lacerations were included, defined as no associated tendon injuries, fractures or tissue loss. Ten (3.4%) of the 297 patients developed wound infections after laceration repair. There was no difference identified between type of suture (absorbable vs nonabsorbable) or staples used for closure and the incidence of wound infection, and neither for laceration location. Median wound length for the infection group was 3.5cm vs 2.5cm in the non-infected group, although this was not statistically significant (p=0.17). The time until closure of the laceration was 867 mins (14.5hrs) in the infected group vs 330 mins (5.5hrs) in the non-infected group (p=0.03).

A third study by Quinn et al was a multicenter prospective cohort study with 2663 patients who presented with lacerations to the Emergency Department. Of the 2663 patients, 69 (2.6%) developed an infection, which was defined as patients who saw a physician within 30 days of the initial laceration for a wound infection and were treated with oral and/or intravenous antibiotics. Risk factors for wound infection included diabetes (6.7% infection rate, p = 0.04), length >5cm (6.7% infection rate, p = 0.001), and contamination with foreign material (4.5% infection rate, p = 0.01). Location of the laceration on the head and neck had a lower risk of infection (1-2%), especially compared to the lower extremity, with an infection rate of 7.5% (p = <0.0001). Only 85 patients presented greater than 12 hours after injury, and only one patient (1.2%) developed an infection. Thirteen of these 85 wounds were left open, with 4 of these undergoing delayed primary closure (up to 96 hours after presentation) and 9 remaining open.

In conclusion, there is controversial evidence about risk factors for developing wound infection after closure of a traumatic laceration. From the literature, patients with laceration length >3.5-5cm, diabetes and evidence of contamination with a foreign object have the most consistent risk of infection. Location of the laceration is also important, as those on the head and neck have a lower incidence of infection. Finally, lacerations greater than 12 hours from injury have a higher risk of infection with delayed closure. Identifying risk factors for infection can aid in determining whether a laceration should be primarily closed on presentation or remain open. It is important to consider each patient and their risk factors on an individual basis, as well as emphasize the necessity for close follow-up.

from Dr. Rana Ballo