Measuring Intra-abdominal Pressure during Spontaneous Breathing Trial: Does It Help?

Background: Respiratory system impairment may be caused by an increase of the intra-abdominal pressure (IAP).

Aim of Work: To assess the role of measuring intra-abdominal pressure in predicting successful weaning from mechanical ventilation.

Methods: 124 patients with acute respiratory failure ARF fulfilling the criteria for weaning were included. Each underwent a 1-hour spontaneous breathing trial (SBT). All clinical, respiratory parameters and mechanics were recorded. IAP was measured using Kron`s technique at the beginning and every 15 minutes till the end of SBT. The mean of IAP during SBT was calculated.

Results: Of 124 patients included in the study, 94 patients achieved successful SBT and extubation, while 31 patients needed re-intubation within 48 hours. Mean IAP was lower in patients that achieved successful SBT compared to patients who didn`t, 7.25 ± 2.28 vs 9.96 ± 2.6, p value < 0.001. Moreover, patients who needed re-intubation within 48 hours had higher mean IAP compared to patients who didn`t, 9.96 ± 1.4 vs 5.92 ± 1.17, P value < 0.001. The cut-off value of mean IAP that predict the need for re-intubation was 8.9 cm H2O with sensitivity and specificity measuring 80% and 52% respectively. The Area Under the Curve (AUC) was 0.97. With multivariate regression analysis, mean IAP was an independent predictor of SBT failure (odds ratio (OR) 1.46, 95% confidence interval (CI) 1.62 to 1.839, p value 0.001). Using Spearman's rank correlation coefficient, it was found that mean IAP was positively correlated with auto ,positive end expiratory pressure, PEEP that measured at the beginning and at the end of SBT, and admission APACHE II score, with correlation coefficient measuring 0.515, 0.595, and 0.4 respectively.