Perioperative considerations in pharmacology

Although anesthesiologists are adept at caring for the perioperative patient and the many physiologic aberrations resulting from surgery and anesthesia, management of perioperative pharmacology presents its own diverse set of challenges. Pharmacologic considerations for the perioperative period include the impact of (1) variable responses based on the patient’s genotype and/or phenotype, (2) preexisting diseases and drug therapies, (3) interactions with herbal supplementation, and (4) the physiologic changes associated with anesthesia. Many surgical patients are on chronic medications for comorbidities unrelated to the diagnosis that brought them to the OR. Anesthesiologists must be aware of both the effects of withdrawing chronic medications and the potential for interactions between “home” medications and the many drugs administered during the perioperative period. In addition to pharmacologic interactions, patient-specific factors like weight and genetic makeup will also impact the anesthetic plan. This chapter will discuss these factors, as well as anesthetic implications of commonly used medications, including herbal supplements. The side effects of nicotine and other aspects of cigarette smoking will also be discussed due to its prevalence and important anesthetic implications. Finally, the impact of anesthesia and surgery on human physiology and subsequent effects on drug metabolism will be reviewed.