The low acceptance rate of continuous positive airway pressure therapy in postoperative patients with untreated obstructive sleep apnea (OSA) indicates the necessity for development of an alternative postoperative airway management strategy. The authors considered whether the combination of high-flow nasal cannula and upper-body elevation could improve postoperative OSA.
This nonblinded randomized crossover study performed at a single university hospital investigated the effect on a modified apnea hypopnea index, based exclusively on the airflow signal without arterial oxygen saturation criteria (flow-based apnea hypopnea index, primary outcome), of high-flow nasal cannula (20 l · min–1 with 40% oxygen concentration) with and without upper-body elevation in patients with moderate to severe OSA. Preoperative sleep studies were performed at home (control, no head-of-bed elevation) and in hospital (30-degree head-of-bed elevation). On the first and second postoperative nights, high-flow nasal cannula was applied with or without 30-degree head-of-bed elevation, assigned in random order to 23 eligible participants.
Twenty-two of the 23 (96%) accepted high-flow nasal cannula. Four participants resigned from the study. Control flow-based apnea hypopnea index (mean ± SD, 60 ± 12 events · h–1; n = 19) was reduced by 15 (95% CI, 6 to 30) events · h–1 with head-of-bed elevation alone (P = 0.002), 10.9 (95% CI, 1 to 21) events · h–1 with high-flow nasal cannula alone (P = 0.028), and 23 (95% CI, 13 to 32) events · h–1 with combined head-of-bed elevation and high-flow nasal cannula (P < 0.001). Compared to sole high-flow nasal cannula, additional intervention with head-of-bed elevation significantly decreased flow-based apnea hypopnea index by 12 events · h–1 (95% CI, 2 to 21; P = 0.022). High-flow nasal cannula, alone or in combination with head-of-bed elevation, also improved overnight oxygenation. No harmful events were observed.
The combination of high-flow nasal cannula and upper-body elevation reduced OSA severity and nocturnal hypoxemia, suggesting a role for it as an alternate postoperative airway management strategy.
- Patients with moderate to severe obstructive sleep apnea (OSA) are considered to have increased risk for postoperative respiratory and cardiovascular complications
- Proper use of continuous positive airway pressure via a face or nasal mask can be effective in reducing risk
- As some patients may not tolerate conventional therapy and/or some institutions may not be able to provide it preoperatively, alternate methods may be of value
- The authors evaluated the role of high-flow nasal cannula (20 l/min with 40% oxygen concentration) with or without 30-degree head-of-bed elevation in patients with moderate to severe obstructive sleep apnea (OSA), all of whom had perioperative sleep studies evaluated by the modified apnea hypopnea index, based exclusively on the airflow signal without arterial oxygen saturation criteria
- Both high-flow nasal cannula and head-of-bed elevation, independently, improved OSA significantly with an additive effect when combined
- The combination of high-flow nasal cannula and upper-body elevation may be considered as an alternative postoperative airway management strategy where continuous positive airway pressure, a standard of care, is refused or is unsuitable