Efficacy of an alveolar recruitment maneuver for improving gas exchange and pulmonary mechanics in anesthetized horses ventilated with oxygen or a helium-oxygen mixture
| Autor: | Charlotte Hopster-Iversen, Bernd Driessen, Klaus Hopster, Lauren R. Duffee |
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| Rok vydání: | 2018 |
| Předmět: |
Male
040301 veterinary sciences medicine.medical_treatment chemistry.chemical_element Respiratory physiology Peak inspiratory pressure Anesthesia General Helium Oxygen Heliox Patient Positioning 0403 veterinary science Random Allocation 03 medical and health sciences 0302 clinical medicine 030202 anesthesiology Fraction of inspired oxygen medicine Animals Horses Respiratory system Mechanical ventilation Cross-Over Studies Continuous Positive Airway Pressure General Veterinary Pulmonary Gas Exchange business.industry 04 agricultural and veterinary sciences General Medicine respiratory system respiratory tract diseases Pulmonary Alveoli Treatment Outcome chemistry Anesthesia Breathing Female Blood Gas Analysis business |
| Zdroj: | American Journal of Veterinary Research. 79:1021-1027 |
| ISSN: | 0002-9645 |
| DOI: | 10.2460/ajvr.79.10.1021 |
| Popis: | OBJECTIVE To evaluate efficacy of an alveolar recruitment maneuver (ARM) with positive end-expiratory pressures (PEEPs) in anesthetized horses ventilated with oxygen or heliox (70% helium and 30% oxygen). ANIMALS 6 healthy adult horses. PROCEDURES In a randomized crossover study, horses were anesthetized and positioned in dorsal recumbency. Volume-controlled ventilation was performed with heliox or oxygen (fraction of inspired oxygen [Fio2] > 90%). Sixty minutes after mechanical ventilation commenced, an ARM with PEEP (0 to 30 cm H2O in steps of 5 cm H2O every 5 minutes, followed by incremental steps back to 0 cm H2O) was performed. Peak inspiratory pressure, dynamic lung compliance (Cdyn), and Pao2 were measured during each PEEP. Indices of pulmonary oxygen exchange and alveolar dead space were calculated. Variables were compared with baseline values (PEEP, 0 cm H2O) and between ventilation gases by use of repeated-measures ANOVAs. RESULTS For both ventilation gases, ARM significantly increased pulmonary oxygen exchange indices and Cdyn. Mean ± SD Cdyn (506 ± 35 mL/cm H2O) and Pao2-to-Fio2 ratio (439 ± 36) were significantly higher and alveolar-arterial difference in Pao2 (38 ± 11 mm Hg) was significantly lower for heliox, compared with values for oxygen (357 ± 50 mL/cm H2O, 380 ± 92, and 266 ± 88 mm Hg, respectively). CONCLUSIONS AND CLINICAL RELEVANCE An ARM in isoflurane-anesthetized horses ventilated with heliox significantly improved pulmonary oxygen exchange and respiratory mechanics by decreasing resistive properties of the respiratory system and reducing turbulent gas flow in small airways. |
| Databáze: | OpenAIRE |
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