Centralized monitored anesthesia care by nurse anesthetist for cataract and glaucoma surgery in a 1:3 ratio: a non-inferiority study

BACKGROUND: Minor Ophthalmic Procedures (MOP), especially cataract or glaucoma surgery, are considered low risk. However, in France, anesthesia must be monitored continuously and carried out by an anesthetist or a nurse anesthetist (NA). The aim was to assess whether an externalized monitored anesthesia care (MAC) would be non-inferior to an individual MAC inside the OR regarding the incidence of severe hypertension, bradycardia, hypoxemia, and surgeon satisfaction.METHODS: We performed a monocentric randomized, non-inferiority trial. Adults undergoing MOP with topical or locoregional anesthesia were randomly assigned to externalized MAC (the NA monitored simultaneously up to 3 patients with a screen monitor repeating the inside monitor) or inside MAC. The primary endpoint was a composite of per-operative complications defined as a blood pressure >200 mmHg, pulse rate <45/min, pulse oximetry <85%, or surgeon satisfaction regarding patient security <3/10. Secondary endpoints included patient and surgeons' overall satisfaction, re-operation within 24 hours, and nurses' overall satisfaction.RESULTS: A total of 900 patients were enrolled (450 in both groups). The externalized MAC was non-inferior to inside MAC as event occurred in 29 patients (6.4%) and 26 patients (5.8%), respectively (adjusted difference - 0.7%). Patient agitation assessed by the surgeon was lower with the inside MAC (adjusted mean difference -0.33; 95%CI -0.61 to -0.04).CONCLUSIONS: Among patients undergoing MOP with topical or locoregional anesthesia, an externalized MAC strategy with a 1:3 NA-to-patient ratio were non-inferior to an inside monitoring on the incidence of severe hypertension, bradycardia, hypoxemia and surgeon satisfaction regarding patient safety.