Is clinical examination an accurate indicator of raised intra-abdominal pressure in critically injured patients'

OBJECTIVES: TO determine the rate of elevated intra-abdominal pressure (IAP ) and to evaluate the accuracy of clinical abdominal examination in the ass essment of IAP in the critically injured trauma patient. DESIGN: A prospective blinded study SETTING: The medical-surgical critical care unit of a university-affiliated regional adult trauma centre. PATIENTS: Forty-two adult blunt trauma victims, who had a mean injury sever ity score of 36. INTERVENTIONS: Urinary bladder pressure was measured daily and classified a s normal (10 mm Hg or less), elevated (more than 10 mm Hg) or significantly elevated (more than 15 mm Hg). A blinded clinical assessment of abdominal pressure was concurrently performed and recorded as elevated or normal. MAIN OUTCOME MEASURES: The sensitivity, specificity and accuracy and the po sitive and negative predictive values of the 2 interventions in identifying elevated IAP. RESULTS: Twenty-one patients (50%) had an elevated IAP at some point during the study. Of the 147 bladder pressure measurements done in these 42 patie nts, 47 (32%) were more than 10 mm Hg and 16 (11%) were more than 15 mm Hg. The sensitivity, specificity, positive predictive value, negative predicti ve value and accuracy of clinical abdominal examination for identifying ele vated IAP were 40%, 94%, 76%, 77% and 77%, respectively. Clinical abdominal examination had a sensitivity, specificity, positive predictive value, neg ative predictive value and accuracy of 56%, 87%, 35%, 94% and 84% respectiv ely, for significantly elevated IAP. CONCLUSIONS: Urinary bladder pressure was commonly elevated among our popul ation of critically injured adults. Compared with bladder pressure measurem ents, clinical abdominal assessment showed poor sensitivity and accuracy fo r elevated IAP. These findings suggest that more routine measurements of bl adder pressure in patients at risk for intra-abdominal hypertension should be performed.