A literature review of data from patients with obstructive sleep apnea (OSA) — a condition that has an increased risk for postoperative complications — showed that preoperative apnea hypopnea index (AHI) correlated with the occurrence of postoperative adverse events, according to a study published in CHEST.

Researchers searched the databases Ovid MEDLINE®, Ovid MEDLINE® In-Process & Other Non-Indexed Citations, and EMBASE for studies that included adults diagnosed with OSA and undergoing surgery. Measurements of interest were preoperative AHI and measurements of nocturnal hypoxemia such as oxygen desaturation index, cumulative sleep time percentage with blood oxygen saturation (SpO2) <90% (cumulative time percentage with SpO2 <90%), minimum SpO2, mean SpO2, and longest apnea duration. Associations between measurements and postoperative adverse events were evaluated for significance.

Of the 1810 initial search hits, 21 were included in the analysis for review. Among the measurements evaluated, AHI was the primary parameter derived from polysomnography used to determine the presence or absence of OSA and the severity. AHI was reported in 19 of the 21 studies, 12 of which showed significant associations between AHI and postoperative complications. Oxygen desaturation index was reported in 4 of the 21 studies, and 2 showed that AHI ≥19 and AHI ≥15 were associated with an increased odds for postoperative delirium (odds ratio, 6.0) and acute kidney injury (odds ratio, 2.9), respectively.

The authors wrote, “From our review of the literature, the most common postoperative complications were oxygen desaturation events, which represent the hallmark presentation of [OSA].”

They added “A significant association between the AHI and postoperative adverse events exists. Complications may be more likely to occur in the category of moderate-to-severe OSA (AHI ≥15).”

Related Articles


Suen C, Ryan C, Mubashir T, et al. Sleep study and oximetry parameters for predicting postoperative complications in patients with OSA [published online October 22, 2018]. CHEST. doi:10.1016/j.chest.2018.09.030