Significant Physiological Disturbances Associated With Non-Routine Event Containing and Routine Anesthesia Cases

A nonroutine event (NRE) is defined as any event that deviates from ideal clinical care for a given patient in a specific clinical situation. We sought to compare anesthesia providers' reporting of NREs with the incidence of significant physiological disturbances (SPDs) detected via retrospective videotape review. SPD criteria were defined prestudy to be deviations of physiological parameters (heart rate, systolic blood pressure, and oxygen saturation) requiring clinical intervention. We hypothesized that SPDs would occur more frequently in NRE cases than in routine (no reported NRE) cases.

A trained observer reviewed videotapes of anesthesia care from 16 randomly selected NRE-containing and 16 matched routine cases for SPD occurrence using custom software. Data were analyzed using nonparametric tests.

Although a preponderance of the anesthetic in both types of cases were uneventful (i.e., free of SPD in 97 ± 1.6% of routine case time versus 89 ± 3.9% of NRE case time), there was at least one SPD episode in 69% of routine and 88% of NRE cases. NRE-containing cases had significantly more SPDs than routine cases (1.4 ± 0.9 SPDs/case hour for NRE versus 0.8 ± 0.3 for routine cases). Twice as many SPDs during NRE-containing cases were clinically related to a reported NRE as opposed to unrelated.

SPDs occur more often in NRE-containing cases. The incidence of approximately one NRE-independent SPD per case was similar in NRE-containing and routine case. Further research is needed to ascertain the relationship of both NREs and SPDs to patient outcomes.