Obstructive sleep apnea is a prevalent condition which significantly affects the quality of life for up to 38 percent of the general adult population, and a far greater percentage of elderly and obese individuals.1 Although adequate management of sleep apnea is important for day-to-day life, it is even more so when it comes to postoperative care. Studies have shown that patients with moderate to severe sleep apnea are more likely to experience cardiovascular or respiratory complications after surgery. According to a study conducted by Memtsoudis et al., patients with postoperative sleep apnea were more likely to require ventilation and intensive care as well as progressive/intermediate care prior to leaving the hospital. The authors also noted increased economic burden of care associated with postoperative sleep apnea.2
The current intervention for obstructive sleep apnea is continuous positive airway pressure, which can be accomplished using either a face or nasal mask. However, the efficacy of this intervention for improving postoperative outcomes specifically has remained contentious,3 and adherence to this intervention in the perioperative period among patients with newly diagnosed obstructive sleep apnea remains low. One study showed that only 33 percent of newly diagnosed patients used continuous positive airway pressure for more than 4 hours overnight.4 Alongside continuing research on preoperative interventions, postoperative care for patients with obstructive sleep apnea should also be considered.
Given the systemic undertreatment of postoperative obstructive sleep apnea as well as increased prevalence of apnea-related morbidity, authors Sakaguchi et al. sought to explore one strategy to improve breathing in patients with sleep apnea while recovering from surgery: a combination of high-flow nasal cannula and upper-body elevation.5 The non-blinded randomized crossover study took place from 2019 to 2021 in a single Japanese hospital and included 23 participants who were screened and confirmed to have obstructive sleep apnea prior to admission. The participants were randomized to receive either no head elevation on the first postoperative night and 30 degrees of head elevation on the second night, or vice versa, in addition to a high-flow nasal cannula. The authors measured changes in the apnea hypopnea index as their primary outcome.
The reported findings were promising: the addition of the 30-degree head elevation significantly decreased the apnea hypopnea index for patients with newly diagnosed obstructive sleep apnea. More specifically, the elevation was found to decrease apnea episode frequency, whereas the high-flow nasal cannula improved overall nocturnal hypoxemia as well as episode frequency. This would suggest that both the high-flow nasal cannula and the head elevation reduced different measures of apnea severity, which would explain their synergy when used in conjunction. The combination of head elevation and high-flow nasal cannula decreased overall flow-based apnea hypopnea index by a significant 38 percent.
Notably, rigorous screening for sleep apnea was performed prior to this study, which might not be as realistic in a normal clinical setting. However, such a non-invasive intervention may be used as a widespread preventative measure in high-risk patients, such as the obese or the elderly, if conventional treatment is not tolerated or accepted.
These findings would suggest that very minimal intervention is necessary to reduce the frequency of sleep apnea-related postoperative complications, which could possibly contribute to increased clinical adherence and therefore, reduced postoperative morbidity. Furthermore, while it has been proposed that variations in the application of continuous positive airway pressure have contributed to varying levels of efficacy, the proposed head elevation technique can be easily replicated across a wide range of medical settings.
References
1 Senaratna, C. V., Perret, J. L., Lodge, C. J., Lowe, A. J., Campbell, B. E., Matheson, M. C., Hamilton, G. S., & Dharmage, S. C. (2017). Prevalence of obstructive sleep apnea in the general population: A systematic review. Sleep medicine reviews, 34, 70–81. https://doi.org/10.1016/j.smrv.2016.07.002
2 Memtsoudis, S. G., Stundner, O., Rasul, R., Chiu, Y. L., Sun, X., Ramachandran, S. K., Kaw, R., Fleischut, P., & Mazumdar, M. (2014). The impact of sleep apnea on postoperative utilization of resources and adverse outcomes. Anesthesia and analgesia, 118(2), 407–418. https://doi.org/10.1213/ANE.0000000000000051
3 Nagappa, M., Mokhlesi, B., Wong, J., Wong, D. T., Kaw, R., & Chung, F. (2015). The Effects of Continuous Positive Airway Pressure on Postoperative Outcomes in Obstructive Sleep Apnea Patients Undergoing Surgery: A Systematic Review and Meta-analysis. Anesthesia and analgesia, 120(5), 1013–1023. https://doi.org/10.1213/ANE.0000000000000634
4 Guralnick, A. S., Pant, M., Minhaj, M., Sweitzer, B. J., & Mokhlesi, B. (2012). CPAP adherence in patients with newly diagnosed obstructive sleep apnea prior to elective surgery. Journal of clinical sleep medicine : JCSM : official publication of the American Academy of Sleep Medicine, 8(5), 501–506. https://doi.org/10.5664/jcsm.2140
5 Sakaguchi, Y., Nozaki-Taguchi, N., Hasegawa, M., Ishibashi, K., Sato, Y., & Isono, S. (2022). Combination Therapy of High-flow Nasal Cannula and Upper-body Elevation for Postoperative Sleep-disordered Breathing: Randomized Crossover Trial. Anesthesiology, 137(1), 15–27. https://doi.org/10.1097/ALN.0000000000004254
