Comparison of four methods of lung volume recruitment during high frequency oscillatory ventilation

• DOI: 10.1007/s00134-009-1628-8
• Publication Date: 2009-09-14T13:35:36Z
• Authors: Anastasia Pellicano; David G. Tingay; John F. Mills; Stephen Fasulakis; Colin J. Morley; Peter A. Dargaville
• Keywords: Analysis of Variance; Pulmonary Atelectasis; Respiratory Distress Syndrome, Newborn; Cross-Over Studies; Time Factors; Pulmonary Gas Exchange; Swine; Airway Resistance; Infant, Newborn; Oxygen Inhalation Therapy; High-Frequency Ventilation; Disease Models, Animal; Random Allocation; 03 medical and health sciences; 0302 clinical medicine; Animals, Newborn; Tidal Volume; Animals; Humans; Blood Gas Analysis; Lung Volume Measurements; Tomography, X-Ray Computed

To compare four methods of volume recruitment upon initiation of high frequency oscillatory ventilation (HFOV).Anesthetized intubated neonatal piglets (n = 10) underwent repeated saline lavage, followed by conventional mechanical ventilation (CMV). After transition to HFOV at a mean airway pressure 8 cmH2O above CMV (P(basal)), four methods of lung volume recruitment were tested in each animal in random order: Escalating--step-wise pressure increments over 6 min to a peak mean airway pressure 12 cmH2O above P(basal); Sustained dynamic inflation (DI)--a 20 s inflation to the same peak pressure; DI repeated six times for 1 s; Standard--mean airway pressure set directly at P(basal). After each recruitment method, HFOV continued at P(basal) for 15 min. Thoracic gas volume and distribution of aeration were determined by single slice computed tomography, and oxygenation by arterial blood gas sampling.Escalating recruitment resulted in the greatest thoracic gas volume 15 min post recruitment [77 +/- 3.3% of total lung capacity vs. 70 +/- 4.2% (Sustained DI), 65 +/- 3.5% (Repeated DI),63 +/- 5.1% (Standard); mean +/- SEM; P = 0.042, ANOVA]. All methods resulted in a reduction in non-aerated lung, with the greatest redistribution to normally aerated lung being with Escalating recruitment. Oxygenation 15 min post recruitment was better with the Escalating method than with Repeated DI or Standard recruitment (pO2 307 +/- 41 vs. 159 +/- 36 vs. 134 +/- 39 mmHg, respectively; P = 0.016, ANOVA).Escalating recruitment produced the greatest increase in lung volume and resolution of atelectasis, and is recommended for lung volume recruitment upon initiation of HFOV.