3 Anesthesia and Analgesia for Facial Cosmetic Procedures
Appropriate patient selection is fundamental to maintaining a safe and efficient office-based cosmetic practice.
National, state, medical specialty–specific practice advisories, and local facility policies define minimum standards of care and monitoring.
Short-acting intraoperative sedation, muscle relaxation, and analgesia combined with long-acting antiemesis are the fundamental goals of an ideal anesthetic.
“Twilight” anesthesia often presents greater challenges than a plain local anesthetic or even general anesthesia.
The safest anesthetic techniques are usually local and general anesthesia.1 Many patients who undergo facial cosmetic procedures require more than just light sedation, and many receive deep intravenous sedation without an endotracheal tube. “Twilight” anesthesia or monitored anesthesia care, although it may sound serene and peaceful, is not without risks. The highest likelihood for complications lies in an anesthetic that is in between the local and general anesthetic levels—requiring the most skill and diligence to manage. Patients who are sedated but who do not have an endotracheal tube or laryngeal mask airway in place are more likely to have airway problems than patients who are either completely awake or asleep with an airway device in place.2 Whereas this technique can work well in expert hands with appropriately selected patients, all members of the cosmetic surgery team should be familiar with the pre-, intra-, and postanesthetic challenges in office-based surgeries. As such, this chapter presents critical information that should be shared with all members of the operative team, but is primarily directed toward the surgeon and anesthesiologist or anesthetist.
Many office-based procedure rooms are equipped to handle cases that require only local anesthesia with or without sedation; few are set up to deliver general anesthesia. Therefore, patient selection is of the utmost importance.3 In essence, selection involves assessment of overall health status and the likelihood of a patient to safely tolerate the necessary anesthetics. The American Society of Anesthesiologists (ASA) has classified risk for anesthesia by preexisting illness of the patient and the surgery to be performed ( Table 3.1 ). It is safest to limit office-based surgery under local anesthesia with/or without intravenous sedation to patients with an ASA I or ASA II classification.4 An airway assessment should also be performed on all patients if deep sedation is to be given ( Fig. 3.1 ). A Mallampati score of greater than II may be associated with a higher likelihood of airway complications if a patient becomes excessively sedated. In such cases, sedation directed by a trained anesthesia provider may offer an extra margin of safety. If the delivery of a general anesthetic is required, patient suitability in an office-based setting must be in line with the facility policies and in consultation with an appropriate anesthesia provider.
Technical Aspects of Procedure
Requirements for the monitoring of patients during office-based procedures can vary by national mandates (e.g., the Joint Commission), state regulations (e.g., Department of Health), professional society practice advisories (e.g., ASA Guidelines for Office-Based Anesthesia), and local facility policies.3,5 If intravenous sedation is to be administered, it is recommended that procedure rooms have the following basic equipment to accommodate these cases:
Automatic blood pressure monitor
An operating table or reclining operating chair
Adequate space to transfer a patient to a gurney
Equipment to manage airway emergencies and a crash cart within the room may provide an extra margin of safety.
Although there is discussion on the inclusion of routine capnography (CO2 monitoring) for moderate to deep sedation cases, it is generally not a requirement. The requirements for rooms that are set up to deliver general anesthesia with controlled ventilation are beyond the scope of this chapter. However, if gas anesthetics (except for nitrous oxide) and/or succinylcholine are to be used, a malignant hyperthermia cart must be readily obtainable in case of a crisis.
Patients who receive only local anesthetics or minimal sedation may be fast-tracked to Phase II recovery, depending on individual patient response to sedation. Patients who receive moderate to heavy sedation or general anesthesia must go to Phase I recovery, where frequent pulse oximetry, cardiac monitoring, and supplemental oxygen, as well as the equipment and personnel able to perform advanced cardiac life support in the event of an emergency must be available.
Aspiration pneumonia is a serious risk when patients receive moderate or deep sedation. In general, patients who present for facial cosmetic procedures should adhere to the ASA guidelines for preoperative fasting ( Table 3.2 ). NPO is from the Latin for “nothing by mouth.”
Local anesthetics6 work by reversibly blocking nerve conduction. They predominantly block the sensation of sharp pain. Therefore, it is important to share with patients that, in an area that has been adequately anesthetized, the patient will not feel the sharp needle stick during suture placement or incisions with a scalpel, but may feel a vague sensation of pressure.
The two most commonly used local anesthetics are lidocaine and bupivacaine ( Table 3.3 ). Lidocaine (Xylocaine, AstraZeneca, LP, Wilmington, DE) is the most typically used and least expensive agent. The usual total dose that can safely be given is 3 to 5 mg/kg body weight of plain solution or 5 to 7 mg/kg when epinephrine is used as part of the local anesthetic solution. The anesthesia becomes effective after 5 to 10 minutes and lasts, on average, from 45 minutes for a plain local anesthetic solution to ~ 90 minutes for an epinephrine-containing solution. It is important to note that lidocaine doses up to 35 mg/kg are often used during tumescent liposuction. Although such doses of lidocaine exceed the usual recommended maximum, plasma levels achieved through a tumescent technique are generally low and considered safe.
Bupivacaine (Marcaine, Hospira Inc., Lake Forest, IL; Sensorcaine, AstraZeneca Pharmaceuticals LLP, Wilmington, DE; Abbott Laboratories, Abbott Park, IL) is a longer-acting agent than lidocaine, but it is also more expensive and has the possibility of more severe toxicity. The usual total dose that can safely be administered at one time is 2 to 3 mg/kg. Although it takes 10 to 15 minutes to become effective, anesthesia lasts ~ 2 to 4 hours. The addition of epinephrine to bupivacaine does not appear to hasten the onset or prolong the duration of anesthesia. In addition, bupivacaine provides residual pain control after the procedure is completed.
If both lidocaine and bupivacaine are available, they can be mixed together in equal parts and administered with one syringe. This combination gives the advantages of a quicker onset of anesthesia from the lidocaine and a longer duration of action from the bupivacaine. The onset of action of this mixed solution is slower than lidocaine alone and does not last as long as bupivacaine alone.
Cocaine is a topical ester local anesthetic that is used for its rapid onset and excellent hemostatic effect. It is unique among the local anesthetic agents because of its vasoconstrictive properties and its ability to elicit a euphoric effect through stimulation of the central nervous system (CNS). However, excessive stimulation of the sympathetic nervous system can result in multiple untoward cardiovascular responses (tachycardia, hypertension, diaphoresis, and vasospasm). Cocaine is one of the more toxic anesthetics in use and, therefore, should be used with caution and in experienced hands. The recommended dosage is up to 3 mg/kg (up to 200 mg). Tetracaine (Pontocaine, Lippomix, Inc., Novato, CA) is another topical ester anesthetic used frequently in head and neck anesthesia. Maximum recommended dosage is 1 mg/kg.
Adverse reactions to local anesthetics (especially the esters) are not uncommon, but true allergy is very rare. Reported adverse reactions include delayed swelling, localized dermatitis, or mucosal inflammation at the site of administration due to delayed-type (type IV) hypersensitivity.7 Allergic reactions to the esters are usually due to sensitivity to their metabolite, para-aminobenzoic acid, and do not result in cross-allergy to amides. Therefore, amides can be used as an alternative in such patients. General systemic adverse effects are due to the effects of local anesthetics on the conduction of electrical impulses in the CNS (causing tinnitus and seizures) and the heart (causing arrhythmias), which may be severe and potentially fatal. However, toxicity is typically associated with plasma levels that are rarely achieved if proper anesthetic techniques are adhered to (i.e., maximum dose calculation and aspiration prior to injection to minimize likelihood of intravascular injection). Twenty percent intravenous fat emulsion (Intralipid, Fresenius Kabi, Clayton, NC) rescue has recently been shown to be an effective treatment for cardiotoxicity from local anesthetic overdose. Therefore, offices that use large amounts of local anesthetic in a single patient should strongly consider stocking Intralipid in their crash carts.
It is often useful to add specific drugs to the local anesthetic solutions to optimize the anesthetic effect, minimize discomfort, and/or improve the surgical field. Epinephrine and sodium bicarbonate are the most commonly utilized adjuvants. Epinephrine is a potent vasoconstrictor, reducing bleeding at the operative site. It also decreases absorption of the anesthetic agent and is responsible for prolonging the duration of short-acting local anesthetics like lidocaine. Lidocaine and bupivacaine are available in pre-mixed solutions with epinephrine, but these can also be prepared in the office by experienced personnel.
Both lidocaine and bupivacaine are acidic and, therefore, painful when injected. One way to lessen this pain is to add injectable sodium bicarbonate to the local anesthetic solution prior to infiltration. It is essential to use commercially prepared bicarbonate for injection. In general, 1 mL of bicarbonate to every 9 mL of lidocaine or to every 19 mL of bupivacaine works well. The addition of too much bicarbonate to the anesthetic solution can lead to the formation of crystals.