Hypoxemia during procedural sedation in adult patients: a retrospective observational study

Since 2010, new guidelines for procedural sedation and the Helsinki Declaration on Patient Safety have increased patient safety, comfort, and acceptance considerably. Nevertheless, the administration of sedatives and opioids during sedation procedures may put the patient at risk of hypoxemia. However, data on hypoxemia during procedural sedation are scarce. Here, we studied the incidence and severity of hypoxemia during procedural sedations in our hospital.

A historical, single-centre cohort study was performed at the University Medical Centre Utrecht (UMCU), a tertiary centre in the Netherlands. Data from procedural sedation in our hospital between 1 January 2011 and 31 December 2018 (3,459 males and 2,534 females; total, 5,993) were extracted from our Anesthesia Information Management System. Hypoxemia was defined as peripheral oxygen saturation < 90% lasting at least two consecutive minutes. The severity of hypoxemia was calculated as area under the curve. The relationship between the severity of hypoxemia and body mass index (BMI), American Society of Anesthesiologists (ASA) Physical Status classification, and duration of the procedure was investigated. The primary outcome was the incidence of hypoxemia.

Twenty-nine percent of moderately to deeply sedated patients developed hypoxemia. A high incidence of hypoxemia was found in patients undergoing procedures in the heart catheterization room (54%) and in patients undergoing bronchoscopy procedures (56%). Hypoxemia primarily occurred in longer lasting procedures (> 120 min) and especially in the latter phases of the procedures. There was no relationship between severity of hypoxemia and BMI or ASA Physical Status.

This study showed that a considerable number of patients are at risk of hypoxemia during procedural sedation with a positive correlation shown with increasing duration of medical procedures. Additional prospective research is needed to investigate the clinical consequences of this cumulative hypoxemia.