Negative Pressure Wound Therapy with a Syringe Technique for Subcutaneous Hematoma in a Heifer

Objective: The objective of this study was (1) to determine the relationship between syringe volume and pressure generated on evacuation and (2) to report the use of Negative Pressure Wound Therapy (NPWT) with a syringe technique to treat a large subcutaneous hematoma of the trunk in a 2-year-old female Holstein heifer. Methods: (1) One, two, or three syringes of different volumes were attached to a manometer. Syringes were attached to the manometer via connection tubes of different volumes. (2) NPWT using five 100-mL syringes was employed to maintain evacuation of the hematoma cavity in the cow following surgical drainage, with syringes emptied and reset twice daily. Results: (1) The pressures generated from total volumes of two or three syringes were plotted along a regression equation to determine the relationship between negative pressure and the volume of one syringe. Decreases in negative pressure generated from the same volume of syringes were dependent on the inner volume of the connection tubes. (2) NPWT was initially insufficient to keep the large hematoma cavity drained; however, by the fourth day this treatment regime was able to adequately maintain evacuation. All drains were removed on day 11. Conclusions: Substantial negative pressure can be generated by the use of syringes in NPWT, and this technique can be successfully used for fluid evacuation from cavities. NPWT with a syringe technique can be utilized to facilitate the healing of wound cavities in ambulatory large animals.