Anesthetic techniques for subspecialty surgery

This chapter deals with anesthesia for patients undergoing a few specific procedures. Unique surgical and anesthetic considerations associated with each type of procedure are discussed. A simple anesthetic plan for each category of procedure is provided. A few general principles are listed below. • Preoperative evaluation Preoperative evaluation Pay attention to common coexisting medical illnesses such as arterial hypertension and diabetes mellitus and ensure that these patients have taken their scheduled medication. Premedication While patients remain NPO for solid foods 6–8 hours prior to surgery, clear liquids up until 2 hours prior to surgery are acceptable. Patients anxious about the procedure may benefit from oral benzodiazepines such as 1–2 mg of lorazepam, either the night before or morning of surgery. The oral regimen can be supplemented with IV benzodiazepines, such as 1–2 mg of midazolam, prior to surgery when necessary, and especially in those with an anxiety trait. Treat any preoperative pain using the patient's established medication regimen. Regional anesthesia and analgesia The site for the block is marked and a “Patient Safety Time-out” is performed and documented before performing any blocks with due consideration to the patient's anticoagulation status. Induction An IV catheter is placed in the appropriate limb, closest to the anesthesiologist in case the OR table is turned 90 or 180 degrees. The non-invasive blood pressure cuff, placed on the same or opposite limb has to be sized appropriately for large patients. Blood pressure should be measured in the sitting position and marked as “baseline” in patients undergoing shoulder surgery. Maintenance Anesthesia is maintained using oxygen with air or oxygen with nitrous oxide, along with an inhaled anesthetic agent or using a Total Intravenous Anesthetic (TIVA) technique or a combination of the two. Analgesia is achieved using non-opioid drugs (i.e. acetaminophen, NSAIDs), local anesthetic infiltration (when feasible) and IV opioids, the latter carefully titrated. Regional analgesia techniques are used if the block has not already been performed prior to surgery in the patient holding area. Emergence During emergence the patient needs to meet standard extubation criteria. The removal of the laryngeal mask airway (LMA) or endotracheal tube can occur while the patient is still anesthetized (i.e., so-called “deep extubation”) or more awake, depending on the procedure and the desire to minimize coughing and bucking during emergence.