Tissue oxygenation in morbid obesity - The physiological and clinical perspective

In order to reach and maintain a normal physiological performance, each cell of the human body needs an adequate quantity of oxygen. The measurement of oxygen at the cellular level is a significant early marker of local injury. Unlike global markers of oxygen deficit that often detect on-going pathology in the irreversible phase, tissue oxygenation measurement can provide an early therapeutic window for appropriate timely intervention to prevent and revert the damage. The present review describes the physiological principles guiding tissue oxygen levels in the morbidly obese. We describe how the morbidly obese are different from lean patients in terms of oxygen delivery at various tissue levels. The text highlights how pathological alterations in tissue oxygen levels during special situations like trauma, sepsis, and active bleeding can be predicted, interpreted and therapeutically targeted to improve clinical outcomes in morbidly obese patients. The utility of tissue oxygenation monitoring in relevance to morbidly obese patients during the perioperative period along with the possible clinical implications is also discussed. We present the present evidence on the topic and extrapolate the possible future role of this monitoring for various diseased states in morbidly obese patients.