Effects of continuous positive airway pressure administered by a helmet in cats under general anaesthesia. Issue 4 (April 2021)

• Record Type: Journal Article
• Authors: Di Bella, Caterina; Araos, Joaquin; Lacitignola, Luca; Grasso, Salvatore; De Marzo, Linda; Crovace, Alberto Maria; Staffieri, Francesco
• Is Part Of: Journal of feline medicine and surgery. Volume 23:Issue 4(2021)
• Page Start: 337
• Page End: 343
• Publication Date: 2021-04
• Subjects: Continuous positive airway pressure -- oxygenation -- anaesthesia -- atelectasis; Cats -- Diseases -- Periodicals; Cats -- Surgery -- Periodicals; 636.8089
• DOI: 10.1177/1098612X20951279
• Languages: English
• ISSNs: 1098-612X

Abstract

Objectives: The aim of this study was to evaluate the respiratory effects of non-invasive continuous positive airway pressure (CPAP) administered by a helmet in healthy cats under anaesthesia. Methods: Fifteen healthy male cats scheduled for castration were anaesthetised with medetomidine (20 µg/kg), ketamine (10 mg/kg) and buprenorphine (20 µg/kg) intramuscularly. When an adequate level of anaesthesia was achieved, a paediatric helmet was placed on all subjects. The helmet was connected to a Venturi valve supplied with medical air and cats received the following phases of treatments: 0 cmH2 O (pre-CPAP), 5 cmH2 O (CPAP) and 0 cmH2 O (post-CPAP). Each treatment lasted 10 mins. At the end of each phase an arterial blood sample was drawn. The following data were also collected: mean arterial pressure, respiratory rate, heart rate and the anaesthesia level score (0 = awake, 10 = deep anaesthesia). The alveolar to arterial oxygen gradient (P[A-a]O2 ) and the venous admixture (Fshunt) were also estimated. Data were analysed with two-way ANOVA ( P <0.05). Results: The arterial partial pressure of oxygen was higher ( P <0.001) at CPAP (103.2 ± 5.1 mmHg) vs pre-CPAP (77.5 ± 7.4 mmHg) and post-CPAP (84.6 ± 8.1 mmHg). The P(A-a)O2 and the Fshunt were lower ( P <0.001) at CPAP (4.4 ± 2.3 mmHg; 7.4 ± 3.1%) vs pre-CPAP (18.9 ± 6.4 mmHg; 22.8 ± 4.6%) and post-CPAP (15.6 ± 7.3 mmHg; 20.9 ± 4.6 %). No other parameters differed between groups. Conclusions and relevance: Non-invasive CPAP applied by a helmet improves oxygenation in cats under injectable general anaesthesia.