An Obesity Paradox of Asian Body Mass Index after Cardiac Surgery: Arterial Oxygenations in Duration of Mechanic Ventilation

Abstract

Background. Numerous studies have documented an obesity paradox that overweight of Caucasian patients has better prognosis after cardiac surgery. This study is to examine Asian patients' BMI to see whether an obesity paradox exists in DMV after cardiac surgery. Methods. A retrospective study consisted of 428 patients after cardiac surgery from January 2006 to December 2010 in the medical center of Taiwan. The Asian BMI was divided into 3 groups: under-normal weight patients (BMI < 24; n = 165), overweight patients (BMI 24 to <27; n = 130), and obese patients (BMI ≥ 27; n = 133). Multivariable analysis and paired t were used to compare all variables. Results. Overweight patients were significantly associated with the shortest DMV. Under-normal weight patients had significantly better oxygenations of AaDO2 and P/F ratio in the DMV; however, they correlated with the longest DMV, older age, more female, lower LVSV, higher BUN, more dialysis-dependent, and poorer outcomes, namely, 1-year mortality, HAP, reintubation, tracheotomy, and LOS. Conclusions. Asian overweight patients after cardiac surgery have better prognosis. Under-normal weight patients have higher risk factors, longer DMV, and poorer outcomes; even though they have better arterial oxygenations, they seem to need better arterial oxygenations for successful weaning ventilator.

Can Patient Selection Explain the Obesity Paradox in Orthopaedic Hip Surgery? An Analysis of the ACS-NSQIP Registry

“…The obesity paradox describes a counterintuitive phenomenon reported in the medical literature whereby patients who are obese have fewer postoperative complications compared with normal-weight patients [5, 9, 15, 18, 20, 34, 37, 39, 42]. One potential explanation of the obesity paradox is a methodological flaw in many prior studies whereby careful selection of healthier patients who are obese to undergo preplanned surgery (ie, selection bias) creates the appearance of a paradox where none exists.…”

“…The obesity paradox describes the phenomenon whereby patients with higher body weight or body mass index (BMI) have been observed to have reduced mortality in many research studies despite a general consensus among physicians that patients who are obese are at higher risk for surgical complications than their nonobese counterparts [5, 9, 15, 18, 20, 34, 37, 39, 42]. This phenomenon is counterintuitive.…”

“…Studies of coronary artery bypass graft surgery provide indirect evidence that obese and nonobese patients are different; patients who are obese tend to be younger [3, 17, 18, 21, 24, 25, 30, 33, 35, 36, 38, 44] and have better renal function [24, 30] at baseline compared with their nonobese counterparts. Most studies attempt to account for differences between patients who are and who are not obese by adjusting for measured covariates including age and presence of certain comorbidities in regression models [4, 5, 9, 15, 18, 20, 22, 34, 37, 39, 42], but such risk adjustment may be incomplete as a result of residual confounders.…”

“…Although previous studies have explored the relationship between BMI and hip arthroplasty complications [42], these studies typically focused on elective procedures and are thus subject to the selection bias issues mentioned previously. In an effort to overcome the issues of selection bias present in many other studies [4, 5, 9, 15, 18, 20, 22, 34, 37, 39, 42], we used this study design with data obtained from the National Surgical Quality Improvement Project (NSQIP) [1, 6].…”

Obesity Prevalence and Associated Outcomes in Cardiothoracic Patients: A Single-Centre Experience

“…Many authors have not compared outcomes based on standard World Health Organization (WHO) body mass index (BMI) categories or have combined weight groups in comparisons 4,7,11,12,[14][15][16][17][18][19][20][21][22][23][24][25] . Comparability of available studies is therefore limited and this in turn impedes meta-analyses.…”