SAN DIEGO – Patients who undergo dialysis before cholecystectomy face a significantly higher risk for postoperative morbidity but not mortality, results from a large analysis of national data showed.
"We hope that these data will allow surgeons to quantitate the risks that are associated with operating on these patients and help them to relay that information to their patients preoperatively," Sophia F. Tam said at the American College of Surgeons/National Surgical Quality Improvement Program National Conference. "We also would like to further study why these adverse outcomes are occurring, and any preoperative or preventive measures that we can make in order to avoid these adverse outcomes."
Sophia F. Tam
Although cholecystectomy is one of the most commonly performed surgical procedures in the United States, there is a lack of quantitative data on the postoperative risks of the procedure in patients who are undergoing dialysis, said Ms. Tam, a third-year medical student at the State University of New York Downstate Medical Center, Brooklyn.
To examine postoperative outcomes following cholecystectomy in dialysis patients, she and her associates evaluated data from the public use file of the American College of Surgeons National Surgical Quality Improvement Program. The sample included 93,703 patients aged 16 or older who underwent cholecystectomy identified by CPT codes during 2006-2010. Of these, 551 were on chronic dialysis. The researchers used ICD-9 codes to exclude cases caused by trauma and selected a matched control group of 530 nondialysis patients based on age, sex, and surgical approach. Outcomes of interest were morbidity, mortality, and hospital length of stay.
Morbidity was defined as having one or more of the following after cholecystectomy: wound infection, wound disruption, pneumonia, unplanned intubation, pulmonary embolism, being on a ventilator for more than 48 hours, cardiac arrest, myocardial infarction, bleeding requiring transfusion, deep vein thrombosis, sepsis, septic shock, and unplanned return to the operating room.
With univariate analysis, the researchers found that in comparison with nondialysis patients, dialysis patients had higher rates of at least one morbidity (14% vs. 3.6%, respectively), mortality (4.2% vs. 0.3%), and mean hospital length of stay (4.3 vs. 1.2 days). All differences were statistically significant with a P value of less than.0001. Compared with nondialysis patients, dialysis patients had higher rates of infectious, pulmonary, and cardiovascular complications, as well as returns to the OR (all significant with a P value of less than .05).
With multivariate logistic regression adjusted for confounding variables, dialysis patients were more likely than were nondialysis patients to experience at least one morbidity (13.8% vs. 4.7%; adjusted odds ratio 2.3), but there was no difference in mortality between the two groups. Hospital length of stay continued to be significantly higher among dialysis patients, compared with their nondialysis counterparts (a mean of 4.3 vs. 1.4 days; adjusted OR 2.0).
Ms. Tam had no disclosures.