title: Cardiac function is a risk factor for paralysis in thoracoabdominal aortic replacement.
abstract: OBJECTIVE
  We studied factors that influence paralysis risk, renal function, and mortality in thoracoabdominal aortic replacement.
  
  
  METHODS
  We prospectively collected preoperative demographic and intraoperative physiologic data and used univariate and multivariate analyses to correlate this data with risk factors for paralysis. A mathematical model of paraplegia risk was used to study the efficacy of paraplegia reduction strategies. We analyzed preoperative and operative factors for paralysis risk, renal function, and mortality for 217 consecutive patients surgically treated from 1984 through 1996 for 176 thoracoabdominal and 41 thoracic aneurysms at the University of Wisconsin Hospital and Clinics. No patient had intercostal reimplantation or assisted circulation. One hundred fifty patients (group A) received cerebrospinal fluid drainage (CSFD) and low-dose naloxone (1 microg/kg/hour) as adjuncts to reduce the risk of paralysis. Sixty-seven patients (group B) did not receive CSFD and naloxone.
  
  
  RESULTS
  Seventeen deficits occurred in 205 surviving patients: 5 of the 147 in group A (expected deficits = 31) and 12 of the 58 in group B (expected deficits = 13) (p < 0.001). In a multivariate logistic regression model, acute presentation, Crawford type 2 aneurysm, group B membership, and a decrease in cardiac index with aortic occlusion remained significant risk factors for deficit (p < 0.0001). By odds ratio analysis, group A patients had 1/40th the risk of paralysis of group B. The only significant predictor of postoperative renal function was the preoperative creatinine level (p < 0.0001); renal revascularization significantly improved renal function. The mortality rate was 1.6% (2) for patients undergoing elective treatment and 21% (19) for patients who had acute presentations. Acute presentation, age, and the preoperative creatinine level were found to be significant factors for operative mortality in a logistic regression model (p < 0.001) and defined a group at high risk for death.
  
  
  CONCLUSIONS
  CSFD and low-dose naloxone significantly reduce the paralysis risk associated with thoracoabdominal aortic replacement. A decrease in the cardiac index with aortic occlusion is a previously unreported variable that defines a subset of patients at higher risk for paralysis.
authors.affiliation: Department of Surgery, University of Wisconsin-Madison, 53792-7375, USA.
authors.forename: C W
authors.initials: CW
authors.lastname: Acher
authors.forename: M M
authors.initials: MM
authors.lastname: Wynn
authors.forename: J R
authors.initials: JR
authors.lastname: Hoch
authors.forename: P W
authors.initials: PW
authors.lastname: Kranner
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D017544:Aortic Aneurysm, Abdominal / Q000503:physiopathology / Q000601:surgery*; D017545:Aortic Aneurysm, Thoracic / Q000503:physiopathology / Q000601:surgery*; D019917:Blood Vessel Prosthesis Implantation / Q000009:adverse effects; D002302:Cardiac Output / Q000502:physiology; D002555:Cerebrospinal Fluid; D003404:Creatinine / Q000652:urine; D003710:Demography; D004322:Drainage; D005260:Female; D006321:Heart / Q000503:physiopathology*; D006801:Humans; D007668:Kidney / Q000503:physiopathology; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative; D015999:Multivariate Analysis; D009270:Naloxone / Q000008:administration & dosage / Q000627:therapeutic use; D009292:Narcotic Antagonists / Q000008:administration & dosage / Q000627:therapeutic use; D016017:Odds Ratio; D010243:Paralysis / Q000209:etiology* / Q000517:prevention & control; D010264:Paraplegia / Q000209:etiology / Q000517:prevention & control; D011446:Prospective Studies; D015424:Reperfusion; D012307:Risk Factors; D015996:Survival Rate
chemical_list: D009292:Narcotic Antagonists; D009270:Naloxone; D003404:Creatinine