Ideal anesthesiologist supervision ratios highest during first cases
MedWire News: The risk for lapses in supervision of anesthetic nurses by anesthesiologists is highest during the first cases of the day because of the high number of simultaneous critical case periods, shows a study.
"Administrators who want to reduce their anesthesia group's costs by encouraging them to decrease their anesthesiologist supervision ratios need to consider the effect of our findings on the timeliness of first-case starts, which is often a major institutional focus," say the researchers.
A previous simulation study suggested that the first cases of the day would place the greatest strain on anesthesiology supervision needs. In the current study, Richard Epstein (Jefferson Medical College, Philadelphia, Pennsylvania, USA) and Franklin Dexter (University of Iowa, Iowa City, USA) aimed to confirm this hypothesis using data from 15,656 operations performed in 24 operating rooms in a single tertiary care hospital over a 1-year period.
They found that, at a supervision ratio of one anesthesiologist to two registered nurse anesthetists, there would have been at least one 5-minute period in which an anesthesiologist was not available to supervise a critical portion of an operation on 35% of days. At a supervision ratio of 1:3, this increased to 99%.
Provision of an additional "floating" anesthesiologist at a supervision ratio of 1:2 would have reduced lapses to 12% of days, the researchers report in Anesthesiology.
But they caution that substitution with a "floating" anesthesiologist may not always be appropriate. "If complex patients are involved or an extended discussion about management has taken place, such substitution may provide suboptimal patient care."
Almost all periods of the day that required the maximum number of anesthesia providers or contained the highest simultaneous number of critical portions of operations occurred during the first cases of the day. Up to 18% of periods needing the maximum number of providers occurred during the lunch period, and up to 10% in the morning, but no more than 1% in the afternoon.
No more than 2% of periods containing the highest simultaneous number of critical portions of cases occurred outside the first-case period of the day (06:30 to 08:00).
"Decreasing the supervision ratio by anesthesiologists from 1:2 to 1:3 will have a great effect on the timeliness of the start of the first cases of the day due to the high incidence of simultaneous critical portions of cases peaking at that time," say Epstein and Dexter.
The average critical portion of a first-case operation, extending from operating room entry to release of the supervising anesthesiologist, lasted 22.2 minutes.
The researchers suggest that hospitals either accept the inevitability of delays to the start of first cases of the day or they introduce staggered starts. "Unless one of these options is chosen, the consequence will be a marked increase in the incidence of supervision lapses," they conclude.
By Eleanor McDermid