Anesthetic Management: Preoperative Period

Anesthetic Management - Related Factors Contributing to Enhanced Recovery

PREOPERATIVE PERIOD

Patient Education

Cooperation from the patient and family is essential if an ERP is to be effectively implemented. Preop-erative teaching must use plain language and avoid medical jargon. Well-designed printed materials, such as procedure-specific booklets can be given to patients and families with the advice to keep them at the bedside and utilize them during the hospitalization.

Preoperative Risk Assessment & Optimization of Functional Status

Identification of patients at risk for intraopera-tive and postoperative complications, along with preoperative efforts focusing on any comorbidi-ties, can improve surgical recovery. Preoperative assessment is discussed in detail. Although international guidelines evaluating the risk for developing cardiovascular, respiratory, or metabolic complications have been extensively reviewed and published, little attention has been given to assessment and optimization of preopera-tive functional and physiological status. Nonethe-less, some recommendations can be made. For example, routine use of β blockers, especially in patients at low risk, has been associated with an increased risk of stroke; however, perioperative β blockers should be continued in patients already receiving this therapy. Perioperative statins appear to decrease postoperative cardiovascular compli-cations and should not be abruptly discontinued perioperatively. Several procedure-specific scor-ing systems based on patient comorbidity, type of surgery, and biochemical data are being used to predict postoperative mortality and morbidity. In addition, risk-adjusted scoring systems, such as the American College of Surgeons’ National Surgical Quality Improvement Program (NSQIP) and the Society of Thoracic Surgeons’ National Database, can be used to compare outcomes among institutions.

Smoking & Alcohol Cessation

The preoperative period provides not only a time to evaluate surgical risk and optimize medical condi-tions, but also an opportunity to modify habits that can significantly affect a patient’s short-term and long-term health and quality of life. Smoking, drug abuse, and excessive alcohol use are risk factors for the development of postoperative complications, and preoperative and postoperative interventions aimed at modifying these habits can improve sur-gical recovery. A recent meta-analysis found that preoperative smoking cessation, for any type of surgery, reduced postoperative complications by 41%, especially those related to wound healing and the lungs.

Many psychological and pharmacological strat-egies are available to help patients stop excessive alcohol consumption and reduce the risk of alco-hol withdrawal. However, the optimal perioperative program has not been identified.

Guidelines for Food & Fluid Intake

Preoperative fasting and surgical stress induce insu-lin resistance. Furthermore, patients who are not allowed to drink fluids after an overnight fast and patients who receive a bowel preparation experience dehydration, which may increase discomfort and cause drowsiness and orthostatic lightheadedness. Although fasting has been advocated as a preopera-tive strategy to minimize the risk of pulmonary aspi-ration during induction of anesthesia, this benefit must be weighed against the detrimental aspects of this practice.

For instance, research suggests that avoiding preoperative fasting and ensuring adequate hydra-tion and energy supply may moderate postoperative insulin resistance. All international fasting guide-lines allow clear fluids up to 2 h prior to induction of anesthesia in patients at low risk for pulmonary aspiration . This practice has proved to be safe even in morbidly obese patients. Further-more, recent studies have shown that preoperative administration of carbohydrate drinks (one 100-g dose administered the night before surgery and a second 50-g dose 2–3 h before induction of anes-thesia) is safe; can reduce insulin resistance, hun-ger, fatigue, and postoperative nausea and vomiting (PONV); and positively influences immune status. Moreover, postoperative nitrogen loss and the loss of skeletal muscle mass are attenuated.

Magnetic resonance imaging studies in healthy volunteers have shown that the residual gastric vol-ume 2 h after 400 mL of oral carbohydrate (12.5% maltodextrins) is minimal and similar to the resid-ual volume after an overnight fast (mean volume of 21 mL). The safety of this practice has been tested in patients with uncomplicated type 2 diabetes mel-litus, none of whom showed evidence of worsened risk of aspiration. Further studies of preopera-tive oral fluid and carbohydrate administration are needed to elaborate their role in improving short-and long-term perioperative outcomes.