13,000 morbidly obese patients living in the catchment area of your local District General Hospital. The vast majority of obese patients presenting for surgery are relatively healthy and their risk is similar to that of normal weight patients. The aim of preoperative assessment is to identify the presence of obesity related morbidity and preoperative cardiac risk assessment for noncardiac surgery pdf the high-risk patient and minimise the risk of postoperative complication. Obesity not only results in altered respiratory, cardiovascular, endocrine physiology but importantly can result in a chronic inflammatory response driven by visceral adipose tissue.
In certain circumstances, this inflammatory state can confer protective effects in the perioperative period known as the obesity paradox. More specifically the obesity paradox describes the reduction in perioperative cardiac morbidity and mortality up to a BMI of 40. The key areas I will focus on in more detail within the talk are highlighted below. A thorough airway assessment should be performed in attempt to identify those patients with a potentially difficult airway.
In reality the incidence of difficult intubation is no different from the general population on the proviso that the patient is suitably positioned sitting up in a ramped position for laryngoscopy. 50, history of snoring, increasing BMI, presence of beard, lack of teeth.
OSA is common in the obese and is often undiagnosed. Strong predictors of OSA include loud snoring, large collar size, hypertension, and the presence of diabetes, male gender and older age. A well, evaluated screening tool is the STOP-BANG questionnaire, which seeks the presence of these predictive factors. A clear pathway for referral for specialist sleep studies should be identified and CPAP treatment offered as soon as is possible.
The risk of an adverse perioperative cardiac event in obese patients is related to the nature and severity of their underlying heart disease, associated comorbidities, and the type of surgery undertaken. Such comorbidities include hypertension, hyperlipidaemia, ischaemic heart disease, right heart failure secondary to obstructive sleep apnoea and obesity related cardiomyopathy. Patients with obesity should be assessed as any other patient group and the requirement for cardiac based investigations should be made on their comorbidity, functional capacity and magnitude of the anticipated surgery. Functional capacity assessment is accepted as one of the key risk predictors in post-operative outcome for major surgery.
It is well known that the prevalence of increased insulin resistance is strongly associated with increasing BMI. This must be identified and tightly controlled throughout the perioperative period.
Some obese patients will develop the metabolic syndrome which significantly increases the perioperative cardiac risk. There are various definitions but essentially it is a constellation of central obesity, Insulin resistance and Dyslipidaemia and Hypertension.