title: Selective mechanical ventilation of dependent lung regions in the anaesthetized horse in dorsal recumbency.
abstract: The effect of selective mechanical ventilation of dependent lung regions were studied in anaesthetized horses (mean weight 486 kg) in dorsal recumbency. Blood-gas measurements were performed with the horse in the lateral position during spontaneous breathing (before selective intubation) and in dorsal recumbency during spontaneous breathing, general mechanical ventilation, and spontaneous breathing + selective mechanical ventilation. Arterial oxygen tension (PaO2) was 32.3 kPa in the lateral position during spontaneous breathing with a high inspired oxygen fraction (FlO2 greater than 92%). In dorsal recumbency PaO2 decreased to 10.9 kPa during spontaneous breathing and was not significantly affected by general mechanical ventilation (PaO2 12.6 kPa). The institution of selective mechanical ventilation with a selective positive end-expiratory pressure (PEEP) of 20 cm H2O caused a marked increase in PaO2 to an average of 35.3 kPa. It is concluded that selective intubation of dependent regions in the diaphragmatic lobes is a feasible procedure and that selective mechanical ventilation with PEEP markedly improves arterial oxygenation in the anaesthetized horse in dorsal recumbency.
authors.affiliation: Department of Surgery, Faculty of Veterinary Medicine, Swedish University of Agricultural Sciences, Uppsala.
authors.forename: G
authors.initials: G
authors.lastname: Nyman
authors.forename: C
authors.initials: C
authors.lastname: Frostell
authors.forename: G
authors.initials: G
authors.lastname: Hedenstierna
authors.forename: B
authors.initials: B
authors.lastname: Funkquist
authors.forename: C
authors.initials: C
authors.lastname: Kvart
authors.forename: H
authors.initials: H
authors.lastname: Blomqvist
mesh_terms: D000768:Anesthesia, General / Q000662:veterinary*; D000818:Animals; D005260:Female; D006736:Horses / Q000502:physiology*; D008168:Lung / Q000502:physiology*; D008297:Male; D010100:Oxygen / Q000097:blood; D011175:Positive-Pressure Respiration / Q000662:veterinary; D011187:Posture; D011659:Pulmonary Gas Exchange; D012121:Respiration, Artificial / Q000379:methods / Q000662:veterinary*
chemical_list: D010100:Oxygen