Emergency general surgery procedures are associated with high overall morbidity and serious morbidity/mortality, as well as widely varying quality of care among hospitals, a large national study has shown.
Dr. Angela Ingraham
Dr. Angela M. Ingraham, a clinical scholar-in-residence at the American College of Surgeons in Chicago, and her colleagues used the 2005-2008 ACS National Surgical Quality Improvement Project (NSQIP) database to assess the 30-day outcomes of three common emergency general surgery procedures as well as hospital-level performance across procedures. They identified 45,602 patients who underwent emergency appendectomy, cholecystectomy, or colorectal resection at 222 NSQIP-participating hospitals nationwide.
“We selected these procedures because appendectomy and cholecystectomy represent two of the most commonly performed emergency surgery procedures, and emergency colorectal resections are associated with a high risk of adverse events,” the investigators said in the August issue of the journal Surgery.
For the analysis, the outcomes of interest included overall morbidity and serious morbidity/mortality (defined as documentation of at least one of the following NSQIP complications: organ space surgical-site infection, wound dehiscence, neurologic event, cardiac arrest, MI, bleeding that requires transfusion of more than 4 units of blood, pulmonary embolism, ventilator dependence for more than 48 hours, and progressive or acute renal insufficiency or sepsis or septic shock).
Not unexpectedly, patients undergoing emergency colorectal resection fared the worst: Overall, 4,202 of 8,990 colorectal resection patients (46.74%) experienced any morbidity within 30 days of the procedure, and 3,736 (41.56%) experienced serious morbidity or death, the investigators reported. Of the 30,788 patients who underwent appendectomies, 1,984 (6.44%) had any morbidity and 1,140 (3.70%) experienced serious morbidity or death. And of 5,824 patients who had emergency cholecystectomies, 503 (8.64%) had any morbidity and 371 (6.37%) experienced serious morbidity or death, they said (Surgery 2010;148: 217-38).
The investigators used stepwise logistic regression to identify predictors of any morbidity and of serious mortality/morbidity, and to generate patient-level predicted probabilities of an outcome. They used expected probabilities to calculate observed:expected ratios for overall morbidity and serious morbidity/mortality for each hospital.
The risk factors identified as strong predictors of overall morbidity and serious morbidity/mortality following all three procedures were American Society of Anesthesiologists (ASA) class, functional status, and preoperative sepsis, the investigators said. For appendectomies, the presence of abscesses or peritonitis was associated with a significantly higher risk of both overall morbidity and serious morbidity/mortality. Following cholecystectomy, the highest risks of overall morbidity and serious morbidity/mortality were observed with postoperative diagnoses of acute cholecystitis and “other” findings; and for colorectal resection, hemorrhage was associated with the highest risk of overall morbidity.
More favorable outcomes were observed in patients whose emergency appendectomies and cholecystectomies were performed laparoscopically, they noted.
The observed:expected ratio ranges for overall morbidity were 0.26-2.36 for appendectomy, 0-3.04 for cholecystectomy, and 0.45-1.51 for colorectal resection. For serious morbidity/mortality, the ratio ranges were 0.23-2.54 for appendectomy, 0-4.28 for cholecystectomy, and 0.59-1.75 for colorectal resection.
To evaluate the consistency of hospital-level performance across procedures, the investigators included patient outcome information from 95 of the 222 NSQIP hospitals that submitted at least 20 cases of each of the three procedures. Using weighted kappa statistics, they demonstrated substantial variability across emergency cases for most hospitals, which were divided into tertiles based on observed:expected ratios. For overall morbidity for all procedures, seven hospitals (7.4%) were rated in the highest, or best, tertile and eight (8.4%) were rated in the lowest tertile. For serious morbidity/mortality for all procedures, nine hospitals (9.5%) were rated in the highest tertile and eight (8.4%) were rated in the lowest tertile, they reported.
The finding of consistent performance for only a significant minority of the hospitals suggests that most hospitals have areas in which care can be improved, the investigators said. “Given the high-risk nature of emergency surgery, the best practices of hospitals with consistently favorable outcomes should be identified and disseminated to facilitate targeted quality improvement initiatives at hospitals with more variable or worse outcomes.”
The investigators acknowledged that the study included only hospitals participating in NSQIP and, for hospital-level comparisons, only those hospitals submitting the required minimum number of emergency surgery cases across all three procedures. As a result, the generalizability of the findings may be limited, the investigators said.
The investigators reported no financial conflicts of interest relevant to this study.