Influence of the increase of positive end expiratory pressure on the intra-abdominal pressure

Introduction

The intra-abdominal pressure (IAP) usually elevates in critically ill patients and must be monitored to avoid compartmental syndrome. The mechanical ventilation may increase the IAP even more by the transmission of the thoraxic pressure from the diaphragm.

Objective

To assess the effect of the optimization of the positive end expiratory pressure (PEEP) on the increase of the IAP in patients with a diagnosis of intra-abdominal hypertension.

Patients and methods

Fifteen patients needing PEEP optimization and with intra-abdominal hypertension. The measurement of the IAP was obtained by intravesical pressure at five different moments: before and after neuromuscular blockade, right after PEEP optimization, and 6 and 12 hours after this procedure.

Results

Fifteen patients, five female (33.3%) and 10 male (66.7%), aged between 20 and 89 years (mean 61 years) were studied. Seven patients (46.7%) underwent gastroenterological surgeries, five patients (33.3%) were trauma victims and three patients (20%) underwent aorta surgeries. Considering the Burch classification [1], 10 patients had intra-abdominal hypertension grade I (10.4–15 mmHg), four patients had grade II (16–25 mmHg) and one patient had grade III (27.5 mmHg). The initial IAP measurement and the four measurements after PEEP optimization were between 2 and 10 mmHg; the differences among them were not significant (tests realized by Friedman analysis, P = 0.196; therefore > 0.005).

Conclusion

The increment of the PEEP does not alter the levels of intra-abdominal pressure in the first 12 hours after PEEP optimization.