Intraoperative Adverse Events: Risk Adjustment for Procedure Complexity and Presence of Adhesions Is Crucial

Benchmarking the quality of intraoperative care by comparing the rates of intraoperative adverse events (iAEs) necessitates adequate risk adjustment. We sought to identify the patient- and procedure-related risk factors for iAEs.

Our 2007 to 2012 institutional American College of Surgeons NSQIP and administrative databases were linked and then screened for iAEs using the Patient Safety Indicator "Accidental Puncture/Laceration." Intraoperative adverse events were confirmed by systematic review of medical records. Comorbidities were assessed using American College of Surgeons NSQIP variables. Adhesiolysis was determined using CPT codes for lysis of adhesions. Operative complexity was determined using relative value units. Multivariable models were constructed to identify independent predictors of iAEs. Sensitivity analyses were performed in uniform samples of operations.

Of 9,292 patients, 218 iAEs were confirmed in 183 patients. Median patient age was 56 years old and 54% were female. Compared with patients without iAEs, iAE patients were older (median 61 vs 56 years; p < 0.001), more functionally dependent (9% vs 5%; p = 0.028), and had higher American Society of Anesthesiologists class (≥3 in 45% vs 35%; p = 0.004); their procedures were more complex (median relative value units 29 vs 23; p < 0.001), more likely open (48% vs 21%; p < 0.001), and more often required adhesiolysis (44% vs 18%; p < 0.001). In multivariable analyses, adhesiolysis (odds ratio = 2.34; 95% CI, 1.71-3.21; p < 0.001), higher operative complexity (third vs first relative value units quartile: odds ratio = 3.36; 95% CI, 1.66-6.78; p < 0.001; fourth vs first quartile: odds ratio = 5.97; 95% CI, 3.01-11.86; p < 0.001), and open surgical approach (odds ratio = 2.04; 95% CI, 1.39-3.01; p < 0.001) independently predicted iAEs. Sensitivity analyses confirmed adhesiolysis and higher operative complexity as independent iAE predictors.

Adhesiolysis and higher operative complexity predict an increased risk for iAE. Attempts to benchmark the quality of intraoperative care need to adequately risk adjust for these factors.