Perioperative hypoxemia is common with horizontal positioning during general anesthesia and is associated with major adverse outcomes: a retrospective study of consecutive patients

Abstract

BackgroundReported perioperative pulmonary aspiration (POPA) rates have substantial variation. Perioperative hypoxemia (POH), a manifestation of POPA, has been infrequently studied beyond the PACU, for patients undergoing a diverse array of surgical procedures.MethodsConsecutive adult patients with ASA I-IV and pre-operative pulmonary stability who underwent a surgical procedure requiring general anesthesia were investigated. Using pulse oximetry, POH was documented in the operating room and during the 48 hours following PACU discharge. POPA was the presence of an acute pulmonary infiltrate with POH.ResultsThe 500 consecutive, eligible patients had operative body-positions of prone 13%, decubitus 8%, sitting 1%, and supine/lithotomy 78%, with standard practice of horizontal recumbency. POH was found in 150 (30%) patients. Post-operative stay with POH was 3.7 ± 4.7 days and without POH was 1.7 ± 2.3 days (p < 0.0001). POH rate varied from 14% to 58% among 11 of 12 operative procedure-categories. Conditions independently associated with POH (p < 0.05) were acute trauma, BMI, ASA level, glycopyrrolate administration, and duration of surgery. POPA occurred in 24 (4.8%) patients with higher mortality (8.3%), when compared to no POPA (0.2%; p = 0.0065). Post-operative stay was greater with POPA (7.7 ± 5.7 days), when compared to no POPA (2.0 ± 2.9 days; p = 0.0001). Conditions independently associated with POPA (p < 0.05) were cranial procedure, ASA level, and duration of surgery. POPA, acute trauma, duration of surgery, and inability to extubate in the OR were independently associated with post-operative stay (p < 0.05). POH, gastric dysmotility, acute trauma, cranial procedure, emergency procedure, and duration of surgery had independent correlations with post-operative length of stay (p < 0.05).ConclusionsAdult surgical patients undergoing general anesthesia with horizontal recumbency have substantial POH and POPA rates. Hospital mortality was greater with POPA and post-operative stay was increased for POH and POPA. POH rates were noteworthy for virtually all categories of operative procedures and POH and POPA were independent predictors of post-operative length of stay. A study is needed to determine if modest reverse-Trendelenburg positioning during general anesthesia has a relationship with reduced POH and POPA rates.

Evaluation of operating room reverse Trendelenburg positioning and its effect on postoperative hypoxemia, aspiration, and length of stay: a retrospective study of consecutive patients

“…In a previous work, we reported that the perioperative hypoxemia rate was substantial in all operative procedure categories (Dunham et al 2014 ). Although the primary body position during the operative procedure was supine or lithotomy, the standard anesthesia practice was to maintain horizontal recumbency in all patients, except for a few in the sitting position.…”

“…In 2014, our group published an investigation of patients who underwent extra-thoracic procedures under general anesthesia and had preoperative pulmonary stability (Dunham et al 2014 ). We provided evidence to suggest that the substantial rates of perioperative hypoxemia and perioperative pulmonary aspiration (POPA) may have been related to horizontal recumbency.…”

Incidence of hypoxemia in a post-anaesthesia care unit and relevant risk factors: a retrospective study of 14604 patients with general anaesthesia

“…According to literature reports, potential risk factors include age, 6 obesity, 11 12 ASA classification, 10 12 OSAS, 13 14 operating time, 10 12 type of muscle relaxant, 15 16 and intraoperative position. 17 However, researchers reached different conclusions about these factors.…”

Explainable machine learning predictions to help anesthesiologists prevent hypoxemia during surgery

“…Hypoxemia or low arterial blood oxygen tension is an unwanted physiological condition and can cause serious patient harm during general anesthesia and surgery (6). Hypoxemia is associated with cardiac arrest, cardiac arrhythmias, postoperative infections and wound healing impairments, decreased cognitive function and delirium, and cerebral ischemia through a number of metabolic pathways (7).…”