Pediatric Fingertip Injuries: Do Prophylactic Antibiotics Alter Infection Rates?

MATERIAL and METHODS Study design, Setting and Selection of Participants

This prospective randomized control trial was conducted at an urban children's hospital Emergency Department with 56,000 visits annually. The Institutional Review Board (IRB) approved the study prior to subject enrollment. The study period was from September 2000 to July 2004. All patients under 18 years of age presenting to the Emergency Department with a fingertip injury distal to the distal interphalangeal joint were eligible to participate. Patients were excluded from the study if the time from injury to repair was greater than eight hours, if the patients had diabetes, an oncologic disorder, an immune deficiency, a bleeding disorder, used steroids regularly, presented with a grossly contaminated wound, were currently taking antibiotics, or had a previous allergic reaction to cephalosporins.

The study was formulated as an equivalence trial to demonstrate non-inferiority of repair without versus with prophylactic antibiotics. The rate of infection 7 days after repair was the primary outcome variable. Determination of the target sample size was based on a combination of practicality and maximum difference between infection rates consistent with equivalence. It was judged feasible to enroll 160 subjects over the course of the study. Sample sizes of 80 per group would have 80% power to conclude with 95% certainty that the infection rates in the two groups were equivalent. This calculation is based on an upper 1-sided 95% confidence limit for the difference in infection rates, with percent infected of 6.25% in both groups, and the maximum allowable difference resulting in equivalence to be 10.6%.

Intervention

All wounds were treated following a standardized protocol.9, 10 First, the degree of injury was recorded. Fingertips were classified into one of five categories: no laceration (damage to nailbed), simple laceration, loss of skin or pulp, partial amputation or complete amputation. Subungal hematomas were drained by cautery. Hand x-rays were obtained to detect fractures, dislocations, or foreign bodies. Lacerations were irrigated with 500cc normal saline after a digital block with 1% lidocaine (no epinephrine). Devitalized tissue was removed. Skin lacerations and nail bed injuries were repaired with chromic gut. Xeroform gauze was then applied to the repaired finger and a bulky dressing secured. A tetanus booster was given if patient's immunizations were not up-to-date. At discharge study participants were given a standard wound care instruction sheet and a scheduled follow-up appointment at 48 hours. Subjects were told to return immediately to the same Emergency Department if they noticed signs or symptoms of infection, including the presence of redness, warmth, tenderness, swelling, discharge or fever.