Evaluation of fluid pressures of common wound-flushing techniques

Abstract

Objective - To evaluate fluid pressures generated via common wound-flushing techniques. Sample Population - 24 combinations of bottles, needles, a syringe, and a bag. Procedures - 12 medically trained individuals used the following devices to forcefully expel fluid as for wound flushing: full and half-full 1-L and 500-mL bottles with holes in the cap made with 16-, 18-, 20-, and 22-gauge needles; a 35-mL syringe with the same needle sizes; and a 1-L bag placed in a cuff pressurized to 300 mm Hg, with the same needle sizes. Fluid expulsion pressures were measured and compared. Results - The highest pressure generated with the bottle was 3.90 ± 1.30 psi (mean ± SD) with a 16-gauge needle and a full 1-L bottle. The highest pressure generated with the 35-mL syringe was 18.40 ± 9.80 psi with a 16-gauge needle. The lowest pressure generated with the 35-mL syringe was 16.70 ± 6.50 psi with an 18-gauge needle. The bag under pressure generated a pressure of 7.3 ± 0.1 psi with a 16-gauge needle. Needle size did not have a significant effect. Conclusions and Clinical Relevance - Solution bottles of any size and needle gauge do not meet the requirement for satisfactory flushing pressure of 7 to 8 psi. Use of a 35-mL syringe can produce pressure substantially > 7 to 8 psi, which could damage tissues. The most consistent delivery method to generate 7 to 8 psi was use of a 1-L plastic bag within a cuff pressurized to 300 mm Hg.