Michael C Mariorenzi MD, Travis Blood MD, Ross Feller MD, Julie Katarincic MD

Title: Characteristics of Patients Admitted to the Hospital for Cat Bite Injury to the Hand and Wrist

Presenter: Michael Mariorenzi

Brown University/Rhode Island Hospital, Providence, RI

Purpose: The purpose of this study is to identify the characteristics of patients who require admission to the hospital following a cat bite injury to the hand or wrist that present to the emergency department.

Methods: We performed a retrospective chart review of one-hundred and forty- five patients who presented to the emergency department (ED) for cat bit injuries to the hand or wrist. Patient demographics, medical and social history, day of presentation, physical exam, route of antibiotic therapy, and whether or not I & D was performed in the ED, examination findings, laboratory values, and length of stay were collected. The data was analyzed to evaluate differences between patient’s admitted to the hospital versus discharged home. Statistical analysis of the data was performed using odds ratios and students’ t-tests.

Results: Seventy-five of the one-hundred and forty-five patients (51.7%) were admitted to the hospital. Of patients admitted to the hospital 36% had failed oral antibiotics compared to just 6% of patients that were discharged to home (p 0.001). Admitted patients were found to be significantly older and presented to the hospital in a significantly delayed fashion. Physical exam findings including swelling and lymphangitis were found to increase a patient’s risk of hospitalization, 3.6 and 1.7 times respectively. Similarly, admitted patients had significantly higher WBC. No differences between admitted and discharged patients were found in regards to location of bite, history of smoking, or diabetes mellitus.

Fourty-five of the 75 patients admitted (60%) underwent irrigation and debridement (I & D) prior to admission. Forty percent (n=30) of patients underwent I & D in the emergency department, whereas the remaining 20% (n= 15) were performed in the operating room. Five patients (n=5) that underwent a procedure in the emergency department required an intervention in the operating room. Patients undergoing an I & D prior to admission were found to be significantly older than patients admitted for antibiotics therapy alone (p=0.039). There was a trend for increased length of stay for patients undergoing an I & D, however this was not found to be statistically significant (p=0.07).

Conclusion: Cat bites to the upper extremity are serious injuries with roughly 50% of patients presenting to the ED requiring admission. Several factors including older age, delayed presentation and physical exam findings increase a patient’s need for hospital admission. Treatment usually consists of intravenous antibiotics with or without and incision and drainage. Based on these findings, there are certain characteristics that are associated with admission, however, these characteristics do not appear to influence the decision to perform an I&D in the ED. Further prospective studies are needed to evaluate which patients require admission and also require I&D must be performed with specific focus on patient-centered clinical outcomes.

Type of Study: Therapeutic III, IRB Approved

Key words: Cat bite, feline bite, animal bite, hand infection