Background: Major surgery might have a modulating effect on nocturnal breathing patterns. The incidence and course of perioperative sleep-disordered breathing in individuals without a previous diagnosis of obstructive sleep apnea has not been investigated sufficiently so far.
Methods: In this study, polygraphic recordings have been obtained from 37 inpatients without a diagnosis of obstructive sleep apnea syndrome during the preoperative night before and six nights following major surgical procedures. Eligible patients consenting to participate in this study underwent polygraphic recordings including four items (O2-saturation, pulse, nasal air flow and snoring) during the study period. Polygraphic data obtained from the postoperative recordings were compared to preoperative recordings.
Results: Median (IQR [range]) apnea-hypopnea-index (AHI) for the whole group was 6,0 (2,5 - 14,7 [0-32,6]) in the preoperative night and increased in the following six nights post surgery: second night: 5,6 (2,6-15,0 [1,1 - 59,3]); third night: 16,9 (5,6 - 38,8 [2,9 - 64,3]); fourth night: 11,6 (5,9 - 17,3 [0,4 - 39,3]); fifth night: 15,2 (5,7 - 22,2 [0,2 - 55,5]); sixth night: 22,5 (5,2 - 35,4 [0,2 - 67,7]). AHI-scores of the third to sixth night post surgery differed significantly from data observed in the preoperative night.
Conclusion: A significant increase in the AHI occurred frequently after major surgical procedures in the late postoperative period. Sleep-disordered breathings in the late postoperative period deserve attention, as they potentially increase the risk of postoperative complications.
Keywords: Major surgery; Obstructive sleep apnea; Postoperative hypoxemia; Sleep-disordered breathing.