Effects of zero reference position on bladder pressure measurements: an observational study

Annals of Intensive Care

Table 1 Characteristics of the patients (n = 100)

	Total (n= 100)	IAH (n= 9)	Non-IAH (n= 91)	p value
Female gender	52 (52.0%)	8 (88.9%)	44 (48.4%)	0.032^a
Age (years)	53.5 ± 16.1	38.1 ± 2.5	55.0 ± 16.0	0.001^b
BMI (kg/m²)	27.2 ± 10.0	40.4 ± 8.7	25.9 ± 9.2	< 0.0001^b
Emergency surgery	55 (55.0%)	0 (0%)	55 (60.4%)	< 0.0001^a
Bariatric surgery	24 (24.0%)	9 (100%)	15 (16.5%)	< 0.0001^a
APACHE II	11.2 ± 1.7	12.1 ± 2	10.3 ± 1.5	0.183^b
SOFA	4.5 ± 2.8	5.1 ± 3.6	4.0 ± 2.0	0.006^b
ICU mortality	15 (15%)	0 (0.0%)	15 (16.5%)	0.348^a
IAP_MAL (mmHg)	8.5 ± 2.8	12.9 ± 0.6	8.1 ± 2.5	< 0.0001^b

^aFisher's exact test; ^bMann-Whitney U test. APACHE, Acute Physiology And Chronic Health Evaluation II; BMI, body mass index; IAH, intra-abdominal hypertension; IAP_MAL, intra-abdominal pressure at midaxillary line; SOFA, Sequential organ failure assessment.