CHEST Guidelines-Impact-of-Obesity-in-Critical-Illness_2021

Impact-of-Obesity-in-Critical-Illness_2021_chest

Pdf Summary

The rise of obesity has significant implications for critical illness management due to its impact on various organ systems, particularly the respiratory system. Obese patients face respiratory challenges like expiratory flow limitation, atelectasis, and V/Q mismatch, which often result in hypoxemia. Furthermore, obesity hypoventilation syndrome may cause hypercapnia, complicating intubation procedures. In such cases, lung-protective ventilation strategies based on predicted body weight are recommended, though the use of high PEEP (positive end-expiratory pressure) remains controversial. <br /><br />Obesity alters medication pharmacodynamics and pharmacokinetics, necessitating adjusted drug dosing. It also increases the risk of venous thromboembolism (VTE) and infections, emphasizing the importance of proper anticoagulation dosing and catheter management. Despite these challenges, some studies suggest obesity might confer survival advantages in critically ill patients, though this is not well understood and may relate to study design limitations.<br /><br />Obesity notably heightens the risk of acute respiratory distress syndrome (ARDS) and complicates management strategies. Obese patients are prone to ARDS due to factors like V/Q mismatch and atelectasis, necessitating careful ventilation management. Prone positioning and venovenous extracorporeal membrane oxygenation (VV-ECMO) can be considered, though historically, VV-ECMO was avoided due to technical complexity in obese patients.<br /><br />Obese patients also face cardiovascular adjustments, like increased blood volume and cardiac output, influencing resuscitation strategies. Obesity contributes to chronic kidney disease risk, and acute kidney injury may arise due to mechanisms like intraabdominal hypertension and inflammation.<br /><br />The review highlights that obesity alters ICU complications and logistics, affecting thrombosis, infection risk, and medical imaging challenges, requiring attentive fluid management, accurate blood pressure monitoring, and thought-out vascular access. Interestingly, though obesity is generally linked to worsened outcomes in diseases like COVID-19, in certain critical illnesses, it might offer protective effects, a phenomenon termed the "obesity paradox." Further research into the molecular mechanisms in obesity could elucidate its varied influence on critical illness outcomes.

Keywords

obesity

critical illness

respiratory challenges

lung-protective ventilation

pharmacokinetics

venous thromboembolism

acute respiratory distress syndrome

cardiovascular adjustments

ICU complications

obesity paradox