exercised when using diazepam, especially in shorter cases, so that recovery is not delayed [232]. Pain and phlebitis with i.v. or i.m. administration reduces the popularity of diazepam [157].

Lorezepam (1–2 mg p.o. or s.l., 1–2 h preoperatively), is also an effective choice for sedation or anxiolytics. However, the prolonged duration of action may prolong recovery time after shorter cases [233]. Midazolam (5–7.5 mg i.m., 30 min preoperatively, or 2 mg i.v. minutes prior to surgery) is a more potent anxiolytic-sedative medication with more rapid onset and shorter elimination half-life, compared to diazepam [234]. Unfortunately, oral midazolam has unpredictable results and is not considered a useful alternative for preoperative medication [235]. Oral narcotics, such as oxycodone (5–10 mg p.o.), may help relieve the patient’s intraoperative breakthrough pain during cases involving more limited liposuction with minimal potential perioperative sequelae. Parenteral opioids, such as morphine (5–10 mg i.m., or 1–2 mg i.v.), demerol (50–100 mg i.m., or 10–20 mg i.v.), fentanyl (10–20 Pg i.v.), or sufentanil (1–2 ug i.v.), may produce sedation and euphoria and may decrease the requirements for other sedative medication. The level of anxiolytics and sedation is still greater with the benzodiazepines than with the opioids. Premedication with narcotics has been shown to have minimal effects on postoperative recovery time. However, opioid premedication may increase PONV [236, 237].

Antihistamine medications, such as hydroxyzine (50–100 mg i.m, or 50–100 mg p.o.), dimenhydrinate (50 mg p.o., i.m., or 25 mg i.v.), are still used safely in combination with other premedications, especially the opioids, to add sedation and to reduce nausea and pruritus. However, the anxiolytic and amnestic effects are not as potent as the benzodiazepines [238]. Barbiturates, such as secobarbital and pentobarbital, once a standard premedication, have largely been replaced by the benzodiazepines.

Postoperative pulmonary embolism (PE) is an unpredictable and devastating complication with an estimated incidence of 0.1–5%, depending on the type of surgical cases [239], and a mortality rate of about 15% [240]. Risk factors for thromboembolism include prior history or family history of DVT or PE, obesity, smoking, hypertension, use of oral contraceptives and hormone replacement therapy, and patients over 60 year of age [240]. Estimates for the incidence of postoperative DVT vary between 0.8% for outpatients

undergoing herniorrhaphies [241], to up to 80% for patients undergoing total hip replacement [239]. Estimates of fatal PE also vary from 0.1% for patients undergoing general surgeries to up to 1–5% of patients undergoing major joint replacement [239]. The incidence of pulmonary embolism may be more common than reported. One study revealed that unsuspected PE may actually occur in up to 40% of patients with who develop DVT [242].

Most minimally invasive cosmetic surgeries, especially of the head and neck, under local anesthesia, with or without sedation, are considered low risk for DVT or PE. Prevention of DVT and PE should be considered an essential component of the perioperative management, especially for cases which may last more than 2 h, with a general anesthetic used or the patient has increased risk factors for DVT or PE. Although unfractionated heparin reduces the rate of fatal PE [243], many surgeons are reluctant to use this prophylaxis because of concerns of perioperative hemorrhage. The low molecular weight heparins, enoxaparin, dalteparin, ardeparin, and danaparoid, a heparinoid, are available for prophylactic indications. Graduated compression stockings and intermittent pneumatic lower extremity compression devices applied throughout the perioperative period until the patient has become ambulatory are considered very effective and safe alternatives in the prevention of postoperative DVT and PE [244, 245]. Even with prophylactic therapy, PE may still occur up to 30 days after surgery [246]. Physicians should be suspicious of PE if patients present postoperatively with dyspnea, chest pain, cough, hemoptysis, pleuritic pain, dizziness, syncope, tachycardia, cyanosis, shortness of breath, or wheezing [240].

6.5.6 Perioperative Monitoring

The adoption of standardized perioperative monitoring protocol has resulted in a quantum leap in perioperative patient safety. The standards for basic perioperative monitoring were approved by the ASA in 1986 and amended in 1995 [7]. These monitoring standards are now considered applicable to all types of anesthetics, including local with or without sedation, regional, or general anesthesia, regardless of the duration or complexity of the surgical procedure and regardless of

whether the surgeon or anesthesiologist is responsible for the anesthesia. Vigilant and continuous monitoring and compulsive documentation facilitates early recognition of deleterious physiological events and trends, which, if not recognized promptly, could lead to irreversible pathological spirals, ultimately endangering a patient’s life.

During the course of any anesthetic, the patient’s oxygenation, ventilation, circulation, and temperature should be continuously evaluated. The concentration of the inspired oxygen must be measured by an oxygen analyzer. Assessment of the perioperative oxygenation of the patient using pulse oximetry, now considered mandatory in every case, has been a significant advancement in monitoring. This monitor is so critical to the safety of the patient, that it has earned the nick-name “the monitor of life.” Evaluation of ventilation includes observation of skin color, chest wall motion, and frequent auscultation of breath sounds. During general anesthesia with or without mechanical ventilation, a disconnect alarm on the anesthesia circuit is crucial. Capnography, a measurement of respiratory end-tidal CO2, is required, especially when the patient is under heavy sedation or general anesthesia. Capnography provides the first alert in the event of airway obstruction, hypoventilation, or accidental anesthesia circuit disconnect, even before the oxygen saturation has begun to fall. End-expiratory or inspiratory volatile gas monitoring is also extremely useful. All patients must have continuous monitoring of the electrocardiogram (ECG) and intermittent determination of blood pressure (BP), and heart rate (HR) at a minimum of 5-min intervals. Superficial or core body temperature should be monitored. Of course, all electronic monitors must have preset alarms limits to alert physicians prior to the development of critical changes.

While the availability of electronic monitoring equipment has improved perioperative safety, there is no substitute for visual monitoring by a qualified, experienced practitioner, usually a CRNA or an anesthesiologist. During surgeries using local with SAM, if a surgeon elects not to use a CRNA or an anesthesiologist, a separate, designated, certified individual must perform these monitoring functions. Visual observation of the patient’s position is also important in order to avoid untoward outcomes such as peripheral nerve or ocular injuries.

Documentation of perioperative events, interventions, and observations must be contemporaneously performed and should include BP and HR every 5 min

and oximetry, capnography, ECG pattern, and temperature at 15 min intervals. Intravenous fluids, medication dosages in mgs, patient position, and other intraoperative events must also be recorded. Documentation may alert the physician to unrecognized physiological trends that may require treatment. Preparation for subsequent anesthetics may require information contained in the patient’s prior records, especially if the patient suffered an unsatisfactory outcome due to the anesthetic regimen that was used. Treatment of subsequent complications by other physicians may require information contained in the records, such as the types of medications used, blood loss, or fluid totals. Finally, compulsive documentation may help exonerate a physician in many medical-legal situations.

When local anesthesia with SAM is used, monitoring must include an assessment of the patient’s level of consciousness as previously described. For patients under general anesthesia, the level of consciousness may be determined using the bispectral index (BIS), a measurement derived from computerized analysis of the electroencephalogram. When used with patients receiving general anesthesia, BIS improves control of the level of consciousness, rate of emergence and recovery, and cost-control of medication usage. Moreover, BIS monitoring may reduce the risk of intraoperative recall [247].

6.5.7 Fluid Replacement

Management of perioperative fluids probably generates more controversy than any other anesthesia-related topic. For minimally invasive treatments in healthy patients, fluid replacement is not a critical part of the procedure. In this patient population, the intravenous access serves merely as a conduit for the administration of medications. Generally, the typical, healthy, 60 kg patient requires about 100 ml of water/h to replace metabolic, sensible, and insensible water losses. After a 12-h period of fasting, a 60 kg patient may be expected to have a 1 l volume deficit on the morning of surgery. This deficit should be replaced over the first few hours of surgery. The patient’s usual maintenance fluid needs may be met with a crystalloid solution such as lactated Ringer’s solution.

Replacement fluids may be divided into crystalloid solutions, such as normal saline or balance salt

solution, colloids, such as fresh frozen plasma, 5% albumin, plasma protein fraction, or hetastarch, and blood products containing red blood cells, such as packed red blood cells. Generally, balanced salt solutions may be used as standard fluid maintenance and to replace small amounts of blood loss. For every milliliter of blood loss, 3 ml of fluid replacement is usually required [248]. However, as larger volumes of blood are lost, attempts to replace these losses with crystalloid reduces the serum oncotic pressure, one of the main forces supporting intravascular volume. Subsequently, crystalloid rapidly moves into the extracellular space. Intravascular volume cannot be adequately sustained with further crystalloid infusion [249]. At this point, many authors suggest that a colloid solution may be more effective in maintaining intravascular volume and hemodynamic stability [250, 251]. Given the ongoing crystalloid-colloid controversy in the literature, the most practical approach to fluid management is a compromise. Crystalloid replacement should be used for estimated blood losses (EBL) less than 500 ml, while colloids, such as hetastarch may be used for EBLs greater than 500 ml. One milliliter of colloid should be used to replace 1 ml of EBL [248]. However, not all authors agree on the benefits of colloid resuscitation. Moss and Gould [252] concluded that isotonic crystalloid replacement, even for large EBLs, restores plasma volume as well as colloid replacement.

Transfusion of red blood cells is rarely a consideration during minimally invasive cosmetic surgeries. Healthy, normovolemic patients, with hemodynamic and physiologic stability, should tolerate hemoglobin levels down to 7.5 g/dl [253]. The decision to transfuse must be made after careful consideration of the benefits and risks of transfusion and not rely on one transfusion trigger. Transfusion is generally indicated when hemoglobin concentrations fall below 6 g/dl [254]. The management of fluids during more invasive cases such as large volume liposuction or abdominoplasty has been described in detail in other references [255].

6.5.8 Recovery and Discharge

The same intensive monitoring and treatment which occurs in the operating room must be continued in the recovery room under the care of a designated, licensed,

and experienced person for as long as is necessary to ensure the stability and safety of the patient, regardless of whether the facility is a hospital, an outpatient surgical center, or a physician’s office. During the initial stages of recovery, the patient should not be left alone while hospital or office personnel attend to other duties. Vigilant monitoring including visual observation, continuous oximetry, continuous ECG, and intermittent BP and temperature determinations must be continued. Because the patient is still vulnerable to airway obstruction and respiratory arrest in the recovery period, continuous visual observation is still the best method of monitoring for this complication. Supplemental oxygenation should be continued during the initial stages of recovery and continued until the patient is able to maintain an oxygen saturation above 90% on room air.

The most common postoperative complication is nausea and vomiting. The antiemetic medications previously discussed with the same consideration of potential risks may be used in the postoperative period. Ondansetron (4–8 mg i.v. or s.l.) and other serotonin antagonists are probably the safest and most effective antiemetics [213–217]. However, the cost of this medication is often prohibitive, especially in an office setting [218]. Postoperative surgical pain may be managed with judiciously titrated i.v. narcotic medication such as demerol (10–20 mg i.v. every 5–10 min), morphine (1–2 mg i.v. every 5–10 min), or butorphanol (0.1– 0.2 mg i.v. every 10 min).

The number of complications that occur after discharge may be more than twice the complications occurring intraoperatively and during recovery combined [256]. Accredited ambulatory surgical center generally have established discharge criteria. While these criteria may vary, the common goal is to ensure the patient’s level of consciousness and physiological stability. Table 6.8 is one example of discharge criteria which may be used.

Use of medication intended to reverse the effects of anesthesia should be used only in the event of suspected overdose of medications. Naloxone (0.1–0.2 mg i.v.), a pure opiate receptor antagonist, with a therapeutic half-life of less than 2 h, may be used to reverse the respiratory depressant effects of narcotic medications, such as morphine, demerol, fentanyl, and butorphanol. Because potential adverse effects of rapid opiate reversal of narcotics include severe pain, seizures, pulmonary edema, hypertension, congestive heart failure, and cardiac arrest [258], naloxone must