Intra-abdominal Pressure Monitoring During Negative Pressure Wound Therapy in the Open Abdomen

Negative pressure wound therapy (NPWT) is commonly used in open abdomen management, where there may be a simultaneous need for prevention of abdominal hypertension, tamponade of hemorrhage, and continuous fascial tension. The regional pressure dynamics of vacuum dressings are poorly understood.

Three duroc swine underwent mid-line laparotomy and application of vacuum open abdomen dressing, with and without sponge packing. Twenty-five catheters were placed throughout the abdomen to capture and record pressures in each quadrant as the vacuum system was ranged between (-75 mmHg to -200 mmHg pressure). Vital signs and ventilator pressures were measured and recorded concomitantly.

No variations in ventilatory pressures or vital signs were observed with any setting. NPWT changed pressure in seven of seventy-five catheters (9%), five of which were related to abdominal packing. When data were grouped into abdominal wall, perihepatic, perisplenic, and deep abdominal regions, there was no significant change in abdominal pressure when packing was absent. With packing, only the abdominal wall region showed a pressure change, reaching a maximum of 20% of the set vacuum pressure.

NPWT does only little to change the intraabdominal pressure, except in superficial locations in packed abdomens and does not appear to cause hemodynamic changes in a porcine open abdomen model. While NPWT may play an important role in fluid scavenging and fascial tensioning, there are likely to be few benefits or drawbacks specifically related to negative abdominal pressure in the deep abdomen.