Risks in overweight patients and smokers
Overweight patients are considered to be at risk, this is especially true in cases of severe overweight. The additional body mass can lead to numerous complications before, during and after anaesthesia. Overweight patients often suffer from concomitant diseases such as diabetes and high blood pressure.
In addition, there are often problems with cardiac performance and breathing, which increase the risks of anesthesia and surgery. The insertion of the tube into the trachea before surgery can be made considerably more difficult by the fat masses. These can obstruct the airway and thus increase the risk of a false intubation, in which case the tube is accidentally inserted into the esophagus instead of the trachea.
To prevent this, fiber optic instruments with camera are often used in difficult intubations. A further problem can be the correct dosage of the medication required for anesthesia, as for overweight patients a higher dose is required to achieve the desired effect. It is also important to monitor patients closely after the procedure, because overweight patients have an increased risk of thromboses and subsequent embolisms, which can be life-threatening in the case of pulmonary embolism, for example.
Smoking has numerous negative effects on the body and thus also carries an increased risk of complications under anaesthesia. On the one hand, smoking can lead to a restriction of cardiac, vascular and pulmonary function, thus increasing the general risk of surgery. Furthermore, smoking stimulates the production of gastric juice.
Thus, despite supposed sobriety of the patient, a large accumulation of stomach contents can occur due to food and fluid shortage, which increases the risk of vomiting and subsequent penetration of the gastric juice into the respiratory tract (aspiration). In this case there is not only the risk of suffocation, but the acid gastric juice can also cause damage to the lung tissue. In addition, a study has shown that smokers need a higher dosage of anaesthetics and painkillers than non-smokers to achieve the desired effect.
For the anesthetic Propofol, smokers had to use a 38% higher dose to induce anesthesia and a 33% higher dose to maintain anesthesia. The reason for this is still unclear, but the effect of nicotine is suspected. Smokers also have a higher risk of wound healing disorders and thromboses after surgery.
