[Medical Q&A] Are obese patients at higher risk for anesthesia?

Planner: Chinese Medical Association

Reviewer: Lu Haiyang, deputy chief physician, Beijing Friendship Hospital, Capital Medical University

Obesity is a metabolic disease characterized by abnormal fat accumulation caused by environmental, genetic and endocrine factors. Obese people are more likely to suffer from diabetes, hypertension and heart disease. They may encounter some special challenges during surgical anesthesia.

Obese people have their own risks of reduced residual gas in the body, increased oxygen consumption and carbon dioxide (CO2) production, imbalanced ventilation/perfusion ratio, alveolar hypoventilation, and obstructive sleep apnea. Compared with relatively normal people, obese patients may be more prone to hypoxia, difficulty in ventilation, and even suffocation during anesthesia. The increased intra-abdominal pressure caused by obesity can lead to diaphragmatic hernia and reflux aspiration.

For obese patients, doctors will ask whether they are unable to lie flat, sit up to breathe, have any special sleeping positions, and have a history of chest pain and syncope during the preoperative anesthesia visit. Electrocardiograms and cardiac ultrasound are routinely used to check for arrhythmias, myocardial hypertrophy, pulmonary hypertension, and other conditions.

When performing anesthesia for obese patients, experienced anesthesiologists are required to perform the operation and be prepared to deal with complex situations. In addition to conventional instruments and equipment, special preparations also include body positioning frames, special operating tables, large sphygmomanometers, long puncture needles, and pressure sore prevention devices. The pharmacokinetics of many anesthetics and commonly used drugs may change in obese patients, requiring individualized application. Since deep vein thrombosis is a high-risk complication of perioperative period in obese patients, routine thrombosis prevention should be performed after surgery. Prevention strategies include early postoperative activities and the use of intermittent pneumatic pressure pumps and elastic stockings.

In summary, obese patients do face higher risks during surgery and anesthesia, but these risks can be effectively controlled through careful preoperative evaluation and thorough intraoperative management.