Efficacy of high flow nasal cannula as an alternative to continuous positive airway pressure therapy in surgical patients with suspected moderate to severe obstructive sleep apnea.

PURPOSE: To compare the efficacy of High flow nasal cannula (HFNC) as an alternative to Continuous Positive Airway Pressure (CPAP) therapy on the first postoperative night in patients with suspected moderate to severe obstructive sleep apnea (OSA). METHODS: This is randomised controlled trial conducted in a tertiary hospital which included elective surgical patients with STOP-BANG score of 5 and above. Forty patients were randomised into one of the four postoperative treatment groups: CPAP, or HFNC at three different flow rates (20 L/min, 30 L/min and 40 L/min). The primary outcome measured was the number of recorded drops in baseline SpO2 of >4%. Secondary outcomes measured included the need for supplemental oxygen or other interventions and the total number of hours of usage of the device. Patient satisfaction, preference for device and reasons for their preference were also collected. RESULTS: CPAP was used for a significantly fewer number of hours compared to HFNC (at all flow rates) during the first postoperative night. There was no significant difference in the primary outcome or in the requirement for other interventions between the four treatment groups. 73.3% of patients in the HFNC group preferred the use of HFNC to the use of CPAP. Reasons for user preference for HFNC include device comfort, ease of use, reduced noise levels and perception of efficacy. CONCLUSIONS: HFNC could be an useful alternative to CPAP as it is not inferior to CPAP in the perioperative management of OSA and is better tolerated.

Postoperative cardiorespiratory complications and continuous positive airway pressure efficacy in obese patients undergoing noncardiac surgery.

BACKGROUND AND AIMS: One in six Singaporeans has obstructive sleep apnoea (OSA) due to obesity compounded by inherent craniofacial features. We assessed the incidence of cardiopulmonary complications and the effectiveness of continuous positive airway pressure (CPAP) therapy in minimising such complications within an obese population. METHODS: A retrospective study of elective noncardiac surgical patients with a body mass index ≥32 kg/m2 was conducted. Patients at moderate to severe risk of OSA were offered CPAP therapy. CPAP therapy adherence, postoperative complications, length of hospital stay, and type of anaesthesia were analysed. RESULTS: In total, 1400 patients comprising 174 with low risk of OSA (L-OSA) and 1226 with moderate to high risk of OSA were included. Of these, 332 were started on CPAP therapy (C-OSA) while 894 declined CPAP use (R-OSA). There were 10 (0.05%) cardiac events - one (0.6%) in the L-OSA group, six (0.6%) in the R-OSA group and three (0.9%) in the C-OSA group. There were 37 (2.6%) respiratory events - 2 (1.1%) in the L-OSA group, 23 (2.6%) in the R-OSA group, and 12 (3.6%) in the C-OSA group. Multivariate analysis showed no statistical significance in CPAP therapy minimising cardiac (P = 0.147) and respiratory (P = 0.255) complications, when analysed by intention-to-treat. CPAP therapy adherence was 13.6 and 10.2% pre- and postoperatively, respectively. When analysed per protocol, none of the nine patients compliant with both pre- and postoperative CPAP therapy developed cardiopulmonary complications. CONCLUSIONS: Amongst patients with moderate to severe risk of OSA, those who were compliant to perioperative CPAP therapy demonstrated a reduction in cardiopulmonary complications.

Postoperative use of high flow nasal insufflation for obstructive sleep apnea.

BACKGROUND: Continuous positive airway pressure (CPAP) therapy is the gold standard treatment for obstructive sleep apnea (OSA), although, associated with poor patient compliance. Conversely, high flow, humidified, temperature-regulated nasal insufflation of oxygen or air is well tolerated. CASE: We describe our experience of three patients with known or suspected moderate to severe OSA who were poorly compliant to CPAP therapy and received high flow nasal insufflation (HFNI) postoperatively. None had significant episodes of desaturation (SpO2 < 95%) and all patients uniformly reported superior comfort levels than with the CPAP therapy. HFNI generates small amounts of positive end-expiratory pharyngeal pressure, increases inspiratory airflow and decreases dead space ventilation. Due to the open system, less difficulty with the patient-mask interface and improved patient comfort is experienced. These factors help prevent hypopnea and lead to enhanced sleep continuity. CONCLUSIONS: HFNI may be a promising alternative to CPAP therapy in the perioperative setting.