Comparison of single-breath continuous positive airway pressure manoeuvre with inhaled salbutamol to improve oxygenation in horses anaesthetized for laparotomy. (January 2022)

• Record Type: Journal Article
• Authors: Dupont, Julien; Gougnard, Alexandra; Salciccia, Alexandra; Detilleux, Johann; Serteyn, Didier; Sandersen, Charlotte
• Is Part Of: Veterinary anaesthesia and analgesia. Volume 49:Number 1(2022)
• Page Start: 85
• Page End: 94
• Publication Date: 2022-01
• Subjects: alveolar recruitment manoeuvre -- continuous positive airway pressure -- dynamic compliance -- estimated shunt fraction -- horses -- salbutamol; Veterinary anesthesia -- Periodicals; 636.089
• DOI: 10.1016/j.vaa.2021.06.018
• Languages: English
• ISSNs: 1467-2987

Abstract

Abstract: Objective: To compare the efficacy of single-breath continuous positive airway pressure manoeuvre (CPAP-M) with inhaled salbutamol, and a combination of both. Study design: Randomized, clinical study. Animals: A total of 62 client-owned horses (American Society of Anesthesiologists status III–V) anaesthetized for laparotomy. Methods: Horses were premedicated with intravenous (IV) xylazine (0.4–0.6 mg kg –1 ), anaesthesia was induced with midazolam (0.06 mg kg –1 IV) and ketamine (2.2 mg kg –1 IV) and maintained with isoflurane in oxygen using volume-controlled ventilation without positive end-expiratory pressure. If PaO2 was < 100 mmHg (13.3 kPa), either a CPAP-M (50 cmH2 O for 45 seconds) or salbutamol (0.002 mg kg –1 ) was administered. The intervention was considered successful if PaO2 reached 100 mmHg (13.3 kPa). If PaO2 remained < 100 mmHg (13.3 kPa), treatments were switched. PaO2 /Fi O2 ratio and estimated shunt fraction (F-shunt) were derived from data obtained from arterial blood gas measurements. Dynamic compliance (Cdyn ) was calculated from variables recorded at the moment of arterial blood analysis. Fisher's exact tests compared success rates between treatments, and linear models were performed to test whether the treatment modified the values of the measurements; p < 0.05. Results: Salbutamol was the first intervention in 28 horses and was effective in 22 horses. CPAP-M was the first intervention in 34 horses and was effective in 26 horses. CPAP-M after salbutamol was performed in six horses, with four responders, and salbutamol after CPAP-M was administered to eight horses, with one responder. Salbutamol, but not CPAP-M, significantly decreased F-shunt. Both salbutamol and CPAP-M significantly increased Cdyn . Conclusions and clinical relevance: Salbutamol and CPAP-M were comparably effective in improving oxygenation and Cdyn in anaesthetized horses with PaO2 < 100 mmHg (13.3 kPa). Whether combining both treatments might be beneficial needs to be confirmed on a larger number of horses.