490 likes | 659 Views
A multivariate analysis of risk factors leading to acute kidney injury after Gastric bypass surgery. Munis A Mattu, MBBS PGY 3 Internal Medicine Training program Catholic health System Khalid J.Qazi ,MACP Joseph Caruana, MD
E N D
A multivariate analysis of risk factors leading to acute kidney injury after Gastric bypass surgery Munis A Mattu, MBBS PGY 3 Internal Medicine Training program Catholic health System Khalid J.Qazi ,MACP Joseph Caruana, MD Mentor Mentor
Classification by body mass index (BMI) Normal 18.5 - 24.9 Overweight 25.0 - 29.9 Obese >30.0 Class I 30.0 - 34.9 Class II 35.0 - 39.9 Class III > 40.0 Definition of Obesity
WNY State of the Region Report All Adults Aged 18 and over,BMI > 30 Total 18.0% Adults aged 20-54 760,836 • Class II BMI 35 - < 40 (5.2%) 39,563 • Class III BMI > 40 (2.8%) 21,303 • Total Class II and Class III 60,866 • UB Department of Family Medicine, Western New York 1999 Adult Health Risk Assessment Survey, Release 99.1.
Epidemic Impacts National economic costs of Overweight and Obesity = $ 99.2 billion in 1995 US dollar • Direct costs = 5.7% of all US health expenditure • Used definition of obesity at BMI > 29 Wolf & Colditz 1998 study
Local Economic Impact Catholic Health System Year 2002 excluding Gastric Bypass services Total Inpatient Charges for 1364 obese patients = $8.19 million dollars Mean $6,006 per patient
NIH Criteria for Bariatric Surgery • Severe obesity • Failed medical attempts at weight loss • Age 18-64 • Free of serious psychiatric illness and drug abuse
Gastric bypass surgery • National Hospital Discharge Survey (1998 to 2003 ) Prevalence increased from 7.0 to 38.6 per 100,000 adults. 288,000 discharges • ASBS : 16,000 surgeries in 1992, 103,000 in 2003
AKI defined: • An abrupt (within 48 hours) absolute increase in the serum creatinine concentration of ≥ 0.3 mg/dL from baseline Or • An increase in the serum creatinine concentration of ≥ 50 percent from baseline Or • Requirement of renal replacement therapy (RRT). Acute kidney injury network: Mehta, RL, Kellum, JA, Shah, SV, et al. Crit Care 2007; 11:R31.
Objectives • Determine incidence and clinical characteristics of Acute Kidney Injury after open gastric bypass by a single surgical team at Sisters of Charity Hospital. • Primary and secondary prevention of AKI
Methods • Matched case-control study ( age, gender and race). • 2683 open Gastric Bypass patients from June 2000-June 2008 after IRB approval. • Compliance with HIPAA regulations. • Data abstraction conducted from complete medical records , hospital and practice databases.
Study Design • Frequencies and relative frequencies were computed for all categorical variables. • Cochran-Mantel-Haenszel test was used to assess observed differences in regards to binary predictors between the case and control group.
Study Design • Common odds ratio was then estimated along with a corresponding exact 95% confidence interval. • Between group mean differences were assessed through mixed linear model.
Study Design • Multivariate model was constructed using a stepwise conditional logistic regression procedure. • A nominal significance level of 0.05 was used in all testing and all tests were two-sided. • All Statistical analyses were carried out using SAS version 9.1.3 statistical software (Cary, NC).
CONCLUSION Incidence of AKI after open gastric bypass of 2.98.% Associated demographic and clinical characteristics being : 1) Postoperative relative Hypotensionadjusted OR 74.902 ,95% CI (7.3, 768.5) P-value 0.0003 2)OR timeadjusted OR 1.061,95% CI (1.036,1.088) P-value < .0001
Measures for primary and secondary prevention of AKI • Postoperative period strict monitoring and avoidance of postoperative hypotension . • Measures to decrease OR time.
References • 1.Postoperative Rhabdomyolysis Following Laparoscopic Gastric Bypass in the Morbidly Obese .Arch Surg.2004; 139:73-76. • 2. Acute changes in renal function after laparoscopic gastric surgery for morbid obesity. Surgery for Obesity and Related diseases,Volume 2,Issue 3,389 - 392 • 3. Acute Kidney Injury after Gastric Bypass Surgery. Clin J Am Soc Nephrol 2: 426-430, 2007
References • 4. Multivariate Analysis of Risk Factors for Death Following Gastric Bypass for Treatment of Morbid Obesity. Annals of Surgery Volume 239,Number 5,May 2004 • 5. Acute kidney injury network: Critical Care 2007; 11:R31. • 6. Gastric bypass as treatment for obesity: trends, characteristics, and complications. Obesity Research 13(12): 2202–09. 2005