The Impact of Minimally Invasive Surgery (mis) and Operating Room (or) Time On Blood Transfusions and Surgical Site Infections

Santosh J Agarwal, BPharm MS, Michael E Minshall, MPH, Ned Cosgriff, MD, Ross D Segan, MD MBA FACS, Gary V Delhougne, JD MHA. Covidien

Objective: We hypothesized that each thirty minute interval increase in OR time and open surgical procedures, independently, would be associated with an additional risk for blood transfusions, surgical site infections (SSI), higher total discharge costs, and increased hospital length of stay (LOS) among open and laparoscopic appendectomy, cholecystectomy, colectomy and gastric bypass (Roux-en-Y).

Methods: We identified all adult surgical discharges from the Premier Perspective Database^TM for 2010 with principal procedures of open or laparoscopic appendectomy, cholecystectomy, colectomy and gastric bypass. We selected those discharges with OR time between the 1^st and 99^th percentiles (0.5 to 6.5 hours). ICD-9-CM codes were used to identify procedures. We used multivariate logistic regression to estimate the adjusted relative risk of transfusions and SSI while accounting for OR time intervals, procedure and procedural approach (laparoscopic or open), patient characteristics (age, gender, race, anemia, Charlson comorbidity conditions, admission status), and provider characteristics (region, teaching hospital, urban hospital, bed size). We used generalized linear modelling to obtain the adjusted incremental total costs and LOS while adjusting for OR time intervals, procedure and procedural approach, blood transfusions, SSI along with patient and provider characteristics.

Results: Of the 93,129 discharges that met the inclusion criteria, 7.7% discharges included blood transfusions and 1.5% discharges developed SSI. Open procedures were associated with 108% (RR: 2.08, 95%CI: 1.93-2.23) increased risk of blood transfusions and 174% (RR: 2.74, 95%CI: 2.38-3.15) increased risk of SSI compared to laparoscopic procedures. After risk adjustment, each thirty minute interval increase in OR time increased the risk of blood transfusion by 21% (RR: 1.21, 95%CI: 1.19-1.23) and SSI by 20% (RR: 1.20, 95%CI: 1.17-1.24). Cholecystectomy, colectomy and gastric bypass had higher risk of blood transfusion than appendectomy. Colectomy had higher risk of SSI whereas cholecystectomy and gastric bypass had lower risk of SSI compared to appendectomy. After risk adjustment, open surgery increased total costs by $3,566 (95%CI: $3,331-3,801) and LOS by 2.25 days (95%CI: 2.16-2.33) compared to laparoscopic surgery. After risk adjustment, each thirty minute interval increase in OR time increased total costs by $1,456 (95%CI: $1,399-1,514) and LOS by 0.31 days (95%CI: 0.29-0.33).

Conclusion: Each thirty minute interval increase in OR time and open surgical approach were independently associated with increased risk of blood transfusion and SSI, while also increasing total discharge costs and LOS for appendectomy, cholecystectomy, colectomy and gastric bypass. Efforts to adopt minimally invasive surgery and reduce OR time could improve outcomes and save resources for the healthcare system.

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