Short-term effects of neuromuscular blockade on global and regional lung mechanics, oxygenation and ventilation in pediatric acute hypoxemic respiratory failure

Marlon E F Wilsterman; Pauline de Jager; Robert Blokpoel; Inez Frerichs; Sandra K Dijkstra; Marcel J I J Albers; Johannes G M Burgerhof; Dick G Markhorst; Martin C J Kneyber

doi:10.1186/s13613-016-0206-9

Short-term effects of neuromuscular blockade on global and regional lung mechanics, oxygenation and ventilation in pediatric acute hypoxemic respiratory failure

Ann Intensive Care. 2016 Dec;6(1):103. doi: 10.1186/s13613-016-0206-9. Epub 2016 Oct 26.

Authors

Affiliations

¹ Division of Paediatric Intensive Care, Department of Paediatrics, Beatrix Children's Hospital, University Medical Center Groningen, University of Groningen, P.O. Box 30.001, 9700 RB, Groningen, The Netherlands.
² Department of Paediatrics, Nij Smellinghe Hospital, Drachten, The Netherlands.
³ Department of Anaesthesiology and Intensive Care Medicine, University Medical Center Schleswig-Holstein, Campus Kiel, Kiel, Germany.
⁴ Department of Epidemiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
⁵ Division of Paediatric Intensive Care, Department of Paediatrics, VU University Medical Center, Amsterdam, The Netherlands.
⁶ Division of Paediatric Intensive Care, Department of Paediatrics, Beatrix Children's Hospital, University Medical Center Groningen, University of Groningen, P.O. Box 30.001, 9700 RB, Groningen, The Netherlands. m.c.j.kneyber@umcg.nl.
⁷ Critical Care, Anaesthesia, Peri-operative Medicine and Emergency Medicine (CAPE), University of Groningen, Groningen, The Netherlands. m.c.j.kneyber@umcg.nl.

Abstract

Background: Neuromuscular blockade (NMB) has been shown to improve outcome in acute respiratory distress syndrome (ARDS) in adults, challenging maintaining spontaneous breathing when there is severe lung injury. We tested in a prospective physiological study the hypothesis that continuous administration of NMB agents in mechanically ventilated children with severe acute hypoxemic respiratory failure (AHRF) improves the oxygenation index without a redistribution of tidal volume V _T toward non-dependent lung zones.

Methods: Oxygenation index, PaO₂/FiO₂ ratio, lung mechanics (plateau pressure, mean airway pressure, respiratory system compliance and resistance), hemodynamics (heart rate, central venous and arterial blood pressures), oxygenation [oxygenation index (OI), PaO₂/FiO₂ and SpO₂/FiO₂], ventilation (physiological dead space-to-V _T ratio) and electrical impedance tomography measured changes in end-expiratory lung volume (EELV), and V _T distribution was measured before and 15 min after the start of continuous infusion of rocuronium 1 mg/kg. Patients were ventilated in a time-cycled, pressure-limited mode with pre-set V _T. All ventilator settings were not changed during the study.

Results: Twenty-two patients were studied (N = 18 met the criteria for pediatric ARDS). Median age (25-75 interquartile range) was 15 (7.8-77.5) weeks. Pulmonary pathology was present in 77.3%. The median lung injury score was 9 (8-10). The overall median CoV and regional lung filling characteristics were not affected by NMB, indicating no ventilation shift toward the non-dependent lung zones. Regional analysis showed a homogeneous time course of lung inflation during inspiration, indicating no tendency to atelectasis after the introduction of NMB. NMB decreased the mean airway pressure (p = 0.039) and OI (p = 0.039) in all patients. There were no significant changes in lung mechanics, hemodynamics and EELV. Subgroup analysis showed that OI decreased (p = 0.01) and PaO₂/FiO₂ increased (p = 0.02) in patients with moderate or severe PARDS.

Conclusions: NMB resulted in an improved oxygenation index in pediatric patients with AHRF. Distribution of V _T and regional lung filling characteristics were not affected.

Keywords: Acute hypoxemic respiratory failure; Children; Electrical impedance tomography; Lung mechanics; Mechanical ventilation; Neuromuscular blockade; Oxygenation; Pediatric acute respiratory distress syndrome.