A Comprehensive Approach to Manage Morbidly Obese Patients Undergoing Cardiac Surgery in the MENA Region

S. Butt¹, N. Srivastav², G. Bhatnagar¹, S. Abdulaziz³, N. Razzaq¹, O. Lender¹, M. Griffin¹, V. Kakar¹, F. Ashiq¹, A. Kumar¹, Y. Saleem⁴, M. Badiwala¹, J. Ramahi¹, U. Darr^1
1Cleveland Clinic Abu Dhabi, Abu Dhabi, Abu Dhabi ²University of Melbourne, Cleveland Clinic Abu Dhabi, Melbourne, Victoria ³Department of Health Abu Dhabi, Abu Dhabi, Abu Dhabi ⁴All India Institute of Medical Sciences, New Delhi, Delhi, Delhi

Purpose: The MENA region has a high prevalence of diabetes and morbid obesity. To address the needs of these patients, a different mindset and approach are needed. A multi-disciplinary task force at Cleveland Clinic Abu Dhabi reviewed up-to-date literature and summarized vital points for managing such patients.

Methods: An Independent literature search on PubMed©, Medline©, and Google Scholar© was done by the Cleveland Clinic Abu Dhabi (CCAD) Task Force, including members from Cardiac Surgery, Perfusion, Anesthesia, Nursing, and Critical Care. The keywords “Cardiac Surgery” and “Morbid Obesity” were used for the search. Only studies on adults above eighteen were included in the study. Articles published in languages other than English and for those full texts not available were excluded. The CCAD Task Force reviewed the recommendations independently and formulated vital takeaways.

Results: Body mass index (BMI) was the standard for estimating morbid obesity. Every 5-unit increment in BMI elevates the risk of sudden cardiac death by 16%, and morbid obesity is still the most common non-ischemic cause of sudden cardiac death. Morbid obesity appears as an independent risk factor for cardiac surgery-induced acute kidney injury (CS-AKI). Mortality and long-term survival in isolated coronary artery bypass grafting patients amongst 4289 obese patients (BMI >30 kg/m2) and non-obese patients requiring coronary grafting illustrated that in-hospital mortality was significantly lower in obese patients undergoing off-pump surgery than on-pump. Prolonged operative time increases the risk of complications such as blood loss, infection, and organ dysfunction. Difficult intubation can increase the risk of airway trauma and hypoxemia. For cardio-pulmonary-bypass (CPB) circuit calculation, Nadler’s Equation is better as it considers the patient's height. The task force recommended the optimal cannula sizes for such patients. Using two oxygenators and a larger heat exchanger with a proper reservoir is safer for such patients. Lean blood flows based on lean BSA were considered an adequate strategy to manage cardio-pulmonary bypass for these patients.

Conclusion: A multi-institutional task force should be established for the management and guideline development for morbidly obese patients undergoing cardiac surgery, as these patients form a vital and distinct cohort. Women are more vulnerable to adverse outcomes following coronary artery bypass grafting (CABG), and further investigation to establish the guidelines for morbidly obese women is urgently needed. Additional studies are required to validate the lean-BSA-based blood flow calculation protocol for CPB management in morbidly obese patients. Whether off-pump CABG, in comparison to on-pump CABG, offers substantial benefit in this cohort needs to be further investigated.

Identify the source of the funding for this research project: No funding to disclose.