Original Investigation 

Anesthesiology

Continuous vs Intermittent Postoperative Vital Sign Monitoring: A Cluster Randomized Crossover Trial

Ashish K. Khanna, Nathaniel Sean O’Connell, Amit K. Saha, et al

JAMA Netw Open 2026;9;(3):e263290. doi:10.1001/jamanetworkopen.2026.3290

Key Points

Question  Does continuous vital sign monitoring reduce abnormalities in blood pressure, oxygenation, and heart rate during the initial 48 hours after noncardiac surgery?

Findings  In this cluster randomized trial, using 4-week ward clusters among 798 postoperative patients, the duration of oxygen saturation less than 90% was reduced by approximately 30 minutes in continuously monitored patients, whereas hypotension and tachycardia durations did not decrease significantly.

Meaning  The findings of this study suggest that continuous postoperative ward monitoring reduces hypoxemia and warrants robust patient-centric outcomes trials.

Abstract

Importance  Continuous postoperative monitoring on general nursing units detects vital sign abnormalities that are missed with conventional intermittent monitoring. Early recognition may prompt interventions to limit potentially harmful blood pressure, heart rate, and oxygen saturation perturbations.

Objective  To test the hypothesis that continuous unblinded monitoring of vital signs would decrease blood pressure, heart rate, and oxygen saturation abnormalities compared with intermittent monitoring in patients recovering from noncardiac surgery.

Design, Setting, and Participants  This multiple crossover randomized cluster trial in 2 postoperative hospital wards included patients recovering from noncardiac surgery and was conducted from October 7, 2020, to October 7, 2021. Data were analyzed from January to July in 2025.

Intervention  One participating ward was randomized to an initial month of either unblinded or clinician-blinded continuous vital sign monitoring and thereafter alternated at 4-week intervals for 1 year; the other ward always used the alternate monitoring approach. All patients had intermittent vital signs always available, whereas continuous vital signs were only available to clinicians during unblinded weeks. When continuous vital signs were unblinded, alerts at a mean arterial pressure less than 65 mm Hg, an oxygen saturation less than 90%, and a heart rate more than 110 per minute were transmitted to treating teams.

Main Outcomes and Measures  The primary outcomes were durations of hypotension, hypoxemia, and tachycardia exceeding alert thresholds during the initial 48 hours of ward admission or until the third postoperative morning. Secondary outcomes were interventions categorized, with increasing severity, as none, independent nursing intervention, physician notification, or activation of the hospital emergency or rapid response systems.

Results  Among 798 total patients (median [IQR] age, 70.7 [62.5-78.7] years; 440 females [55%]), who included 404 assigned to continuous monitoring and 394 to intermittent monitoring, 561 (70%) with the American Society of Anesthesiologists’ physical status III were included in the final analysis. The duration of oxygen saturation less than 90% was reduced by approximately 30 minutes over 48 hours of monitoring time, in continuously monitored patients (unblinded continuous monitoring group median [IQR], 70.8 [23.1-154.2] minutes vs blinded intermittent group median [IQR], 103.5 [29.5-249.7] minutes; geometric means ratio, 0.86 [95% CI, 0.78-0.95]; P = .002). Hypotension and tachycardia durations were not significantly reduced. The number of interventions was similar, with approximately half in each group receiving new oxygen therapy (unblinded continuous monitoring: 224 [55%] and blinded intermittent monitoring: 214 [54%]).

Conclusions and Relevance  In this cluster randomized crossover trial of continuous compared with intermittent vital sign monitoring, continuous monitoring reduced the duration of desaturation in patients recovering from noncardiac surgery on general hospital wards. Reducing the duration of vital sign abnormalities may decrease the risk of more serious complications, and robust patient-centric outcomes trials seem warranted.

Trial Registration  ClinicalTrials.gov Identifier: NCT04574908