Hypoxemia following hospital discharge after fast-track hip- and knee arthroplasty-a prospective observational study subanalysis

Postoperative hypoxemia is prevalent in hospitalized patients and may adversely affect recovery. However, little data exists on the post-discharge phase or details on duration, severity and potential risk factors. Thus, we investigated the incidence and risk factors for severe desaturation during the first postoperative week after THA/TKA by continuous nocturnal oxygen saturation monitoring. The study was a secondary analysis of a prospective cohort study of 112 patients undergoing fast-track THA/TKA. Patients with known sleep apnea were excluded. Oxygen saturation and heart rate were recorded by a wireless wrist-worn pulse oximeter two nights before- and seven nights after surgery. Data on demographics, opioid consumption and cognitive function were collected from medical charts, patient-diaries and clinical testing, respectively. The primary outcome was occurrence of severe desaturation defined as periods with saturation