Effects of airway pressure release ventilation on blood pressure and urine output in children

Abstract

OBJECTIVE: Increased intrathoracic pressures during airway pressure release ventilation (APRV) may compromise systemic venous return resulting in decreased cardiac output and renal perfusion. We sought to study the short-term effect of APRV on blood pressure (BP) and urine output (UO) in children with acute lung injury (ALI) or acute respiratory distress syndrome (ARDS). DESIGN: Retrospective cohort study. PATIENTS: All patients with ALI/ARDS who were admitted to our Pediatric Intensive Care Unit (PICU) between 1/00 and 06/04, and who were ventilated with APRV (for at least 12 hr) for worsening oxygenation while on conventional ventilation (CV). MEASUREMENTS AND RESULTS: Medical records were reviewed for patients' demographics, Pediatric Risk of Mortality (PRISM III) score, admitting diagnosis, ventilator settings, gas exchange data, heart rate (HR), central venous pressure (CVP), blood pressure (BP), UO, and use of other therapies [sedatives, pressors, inotropes, and intravenous fluid (IVF)]. Eleven patients met our inclusion and exclusion criteria with a mean age of 6.2 +/- 4.8 years (range: 1-15 years), a weight of 35.5 +/- 29.5 kg (range: 12-90 kg), and a PRISM score of 18.4 +/- 9.6 (range: 2-36). Within 10 hrs of APRV, patients' mean airway pressure (Paw) increased from 16.1 +/- 6.6 to 21.1 +/- 5.5 cm of H(2)O (P = 0.04). Despite a higher Paw there were no differences in HR, CVP, BP, UO, IVF and use of other therapies while on CV or APRV (P > 0.10). CONCLUSION: In children with ALI/ARDS, despite a higher Paw, APRV does not affect BP or UO.