ABSTRACT
Obesity is defined as a disease in which excess body fat has accumulated to such an extent that health may be adversely affected. It is challenging to account for obesity when dosing medications in the intensive care unit (ICU). The physiological changes markedly affect distribution, protein binding and elimination of drugs. Obesity is associated with physiological abnormalities, complications and comorbidities in several organ systems. Patients with obstructive sleep apnoea can be more sensitive to the effects of sedative drugs and opioids. Remember obese patients can have undiagnosed obstructive sleep apnoea. In severely obese patients, neural respiratory drive increases to compensate both for raised ventilatory load and inefficiency of the respiratory muscles. In obesity hypoventilation syndrome, this compensatory mechanism fails. Progressive desensitisation of the respiratory centre to carbon dioxide occurs resulting in hypoxia, hypercarbia and apnoeic events.
