Search Results - (Author, Cooperation:C. McKerlie)

2015-07-25

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

Animal Experimentation/*standards ; Animals ; Electronic Health Records ; Female ; Genomics ; Humans ; Male ; Metabolomics ; Mice ; Mice, Knockout ; National Institutes of Health (U.S.) ; Precision Medicine/*economics/*trends ; United States

1432-1238

Key words Liquid ventilation ; Perfluorocarbon ; Pulmonary blood flow ; Haemodynamics ; Microspheres

Springer Online Journal Archives 1860-2000

Medicine

Abstract Objective: Partial liquid ventilation (PLV) improves gas exchange in animal studies of lung injury. Perfluorocarbons (PFCs) are heavy liquids and are therefore preferentially delivered to the most dependent areas of lung. We hypothesised that improved oxygenation during PLV might be the consequence of a redistribution of pulmonary blood flow away from poorly ventilated, dependent alveoli, leading to improved ventilation/perfusion (V/Q) matching. This study investigated whether partially filling the lung with PFC would result in a redistribution of pulmonary blood flow.¶Design: Prospective experimental study.¶Setting: Hospital research institute laboratory.¶Participants: Six anaesthetised pigs without lung injury.¶Interventions: Animals were anaesthetised and ventilated (gas tidal volume 12 ml/kg, PEEP 5, FIO2 1.0, rate 16). Whilst the pigs were maintained in the supine position, regional pulmonary blood flow was measured during conventional gas ventilation and repeated during PLV. Flow to regions of lung was determined by injection of radioactive microspheres (Co57, Sn113, Sc46). Measurements were performed with ventilation held at end-expiratory pressure and, in two PLV animals only, repeated with ventilation held at peak inspiratory pressure.¶Results: During conventional gas ventilation, blood flow followed a linear distribution with the highest flow to the most dependent lung. In the lung partially filled with PFC a diversion of blood flow away from the most dependent lung was seen (p = 0.007), resulting in a more uniform distribution of flow down the lung (p = 0.006). Linear regression analysis (r 2 = 0.75) also confirmed a difference in distribution pattern. On applying an inspiratory hold to the liquid-containing lung, blood flow was redistributed back towards the dependent lung.¶Conclusions: Partially filling the lung with PFC results in a redistribution of pulmonary blood flow away from the dependent region of the lung. During PLV a different blood flow distribution may be seen between inspiration and expiration. The clinical significance of these findings has yet to be determined.

Electronic Resource

1432-1238

Key words Intermittent positive pressure ventilation ; Positive end-expiratory pressure ; High-frequency oscillation ; Volume recruitment maneuvers ; Pulmonary mechanics ; Lung volume

Springer Online Journal Archives 1860-2000

Medicine

Abstract Objective: To determine whether using a small tidal volume (5 ml/kg) ventilation following sustained inflation with positive end-expiratory pressure (PEEP) set above the critical closing pressure (CCP) allows oxygenation equally well and induces as little lung damage as high-frequency oscillation following sustained inflation with a continuous distending pressure (CDP) slightly above the CCP of the lung.¶Material and methods: Twelve surfactant-depleted adult New Zealand rabbits were ventilated for 4 h after being randomly assigned to one of two groups: group 1, conventional mechanical ventilation, tidal volume 5 ml/kg, sustained inflation followed by PEEP 〉 CCP; group 2, high-frequency oscillation, sustained inflation followed by CDP 〉 CCP.¶Results: In both groups oxygenation improved substantially after sustained inflation (P 〈 0.05) and remained stable over 4 h of ventilation without any differences between the groups. Histologically, both groups showed only little airway injury to bronchioles, alveolar ducts, and alveolar airspace, with no difference between the two groups. Myleoperoxidase content in homogenized lung tissue, as a marker of leukocyte infiltration, was equivalent in the two groups.¶Conclusions: We conclude that a volume recruitment strategy during small tidal volume ventilation and maintaining lung volumes above lung closing is as protective as that of high-frequency oscillation at similar lung volumes in this model of lung injury

Electronic Resource