**8. General anesthesia**

The judgment to use a general anesthesia in geriatric patients is determined by the type of surgery, and anesthesiologist and surgeon preference. Anesthesia preparation time, start time of surgery, length of surgery, time to sit, and time to walk were shorter in GA. Most general anesthetic agents depress cardiovascular and respiratory function as well as change consciousness. There are several adverse effects that happen in unpredictable, varying proportions of geriatric patients, while the cardiorespiratory adverse effects are dose-related. Oxygen desaturation and hypoxemia happens faster in the geriatric patients. Hence, appropriate preoxygenation is critical.

Alterations in pharmacokinetics and pharmacodynamics in geriatric patients affect considerably with the final action of anesthetic drugs and increase the adverse effects. Advanced age is undoubtedly related with a reduction in median effective dose requirements for all anesthetic agents. In geriatric patients, an induction dose of anesthetic agent is substantially reduced. The titration of admistered drugs is extremely recommended. Ketamine should not be used in the patient with cardiac disease or hypertension. GA might be better in geriatric patients with severe cardiorespiratory diseases. Moreover, dementia increases with age. When GA is applied, the time required for clinical recovery from neuromuscular blockade is obviously increased in geriatric patients for nondepolarizing muscle relaxants. A short or intermediate-acting muscle relaxant is planned when tracheal extubation is needed. Once paralysis is not compulsory, laryngeal mask airway could be performed in the geriatric patients with a low risk of aspiration. Careful perioperative fluid balance is required in the geriatric patients. Consequently, GA in geriatric patients is associated with hypothermia, leading to increased morbidity.
