title: Risk factors for morbidity and mortality after colectomy for colon cancer.
abstract: OBJECTIVE
  Comorbid conditions affect the risk of adverse outcomes after surgery, but the magnitude of risk has not previously been quantified using multivariate statistical methods and prospectively collected data. Identifying factors that predict results of surgical procedures would be valuable in assessing the quality of surgical care. This study was performed to define risk factors that predict adverse events after colectomy for cancer in Department of Veterans Affairs Medical Centers.
  
  
  METHODS
  The National Veterans Affairs Surgical Quality Improvement Program contains prospectively collected and extensively validated data on more than 415,000 surgical operations. All patients undergoing colectomy for colon cancer from 1991 to 1995 who were registered in the National Veterans Affairs Surgical Quality Improvement Program database were selected for study. Independent variables examined included 68 preoperative and 12 intraoperative clinical risk factors; dependent variables were 21 specific adverse outcomes. Stepwise logistic regression analysis was used to construct models predicting the 30-day mortality rate and 30-day morbidity rates for each of the ten most frequent complications.
  
  
  RESULTS
  A total of 5,853 patients were identified; 4,711 (80 percent) underwent resection and primary anastomosis. One or more complications were observed in 1,639 of 5,853 (28 percent) patients. Prolonged ileus (439/5,853; 7.5 percent), pneumonia (364/5,853; 6.2 percent), failure to wean from the ventilator (334/5,853; 5.7 percent), and urinary tract infection (292/5,853; 5 percent) were the most frequent complications. The 30-day mortality rate was 5.7 percent (335/5,853). For most complications, 30-day in-hospital mortality rates were significantly higher for patients with a complication than for those without. Thirty-day mortality rates exceeded 50 percent if postoperative coma, cardiac arrest, a pre-existing vascular graft prosthesis that failed after colectomy, renal failure, pulmonary embolism, or progressive renal insufficiency occurred. Preoperative factors that predicted a high risk of 30-day mortality included ascites, serum sodium >145 mg/dl, "do not resuscitate" status before surgery, American Society of Anesthesiologists classes III and IV OR V, and low serum albumin.
  
  
  CONCLUSIONS
  Mortality rates after colectomy in Veterans Affairs hospitals are comparable with those reported in other large studies. Ascites, hypernatremia, do not resuscitate status before surgery, and American Society of Anesthesiologists classes III and IV OR V were strongly predictive of perioperative death. Clinical trials to decrease the complication rate after colectomy for colon cancer should focus on these risk factors.
authors.affiliation: Department of Surgery, Saint Louis University School of Medicine and the St. Louis VA Medical Center, Missouri, USA.
authors.forename: W E
authors.initials: WE
authors.lastname: Longo
authors.forename: K S
authors.initials: KS
authors.lastname: Virgo
authors.forename: F E
authors.initials: FE
authors.lastname: Johnson
authors.forename: C A
authors.initials: CA
authors.lastname: Oprian
authors.forename: A M
authors.initials: AM
authors.lastname: Vernava
authors.forename: T P
authors.initials: TP
authors.lastname: Wade
authors.forename: M A
authors.initials: MA
authors.lastname: Phelan
authors.forename: W G
authors.initials: WG
authors.lastname: Henderson
authors.forename: J
authors.initials: J
authors.lastname: Daley
authors.forename: S F
authors.initials: SF
authors.lastname: Khuri
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000714:Anastomosis, Surgical / Q000009:adverse effects / Q000401:mortality / Q000706:statistics & numerical data; D003082:Colectomy / Q000009:adverse effects* / Q000401:mortality / Q000706:statistics & numerical data; D003110:Colonic Neoplasms / Q000401:mortality / Q000601:surgery*; D015897:Comorbidity; D005260:Female; D005544:Forecasting; D017052:Hospital Mortality; D006787:Hospitals, Veterans / Q000706:statistics & numerical data; D006801:Humans; D007415:Intestinal Obstruction / Q000453:epidemiology; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011014:Pneumonia / Q000453:epidemiology; D011446:Prospective Studies; D012042:Registries; D012121:Respiration, Artificial / Q000706:statistics & numerical data; D012307:Risk Factors; D016896:Treatment Outcome; D014481:United States / Q000453:epidemiology; D014552:Urinary Tract Infections / Q000453:epidemiology