The majority of the aforementioned procedures can be performed with monitored anesthesia care (MAC). Although the ASA recently revised the definitions of sedation and anesthesia, the term monitored anesthesia care continues to be used [18]. Of note, the ASA statement mandates exhaled end-tidal carbon dioxide (E_tCO₂) monitoring during both moderate and deep sedation with effect from July 2011. Even though it is of questionable utility in some situations, failure to adhere is a problem in case of litigation [19, 20]. It has been recently demonstrated that majority of patients thought to be receiving moderate sedation are frequently under general anesthesia and even deep general anesthesia [21]. Sedation related adverse events are in fact more frequent in patients receiving MAC [22, 23]. The majority of the adverse events are airway related. The importance of appropriate preparation in terms of drugs and equipment cannot be overstated [24].

The use of airway adjuncts like nasal airway is described in the chapter on airway management for gastrointestinal endoscopic procedures. Some of these techniques reduce the incidence of hypoxemia and its associated complications. In fact, such a management is demonstrated to improve the safety and increase the efficiency in many endoscopic procedures [25, 26] including obese patients.

The choice of drugs and their administration are no different than in any other care setting. Pk/Pd variability is a major concern. Propofol is best administered as a regulated bolus (titrated to the effect) followed by an infusion. Although addition of opioid decreases the propofol requirement, the practice also increases the Pk/Pd variability.

Patients with a history of sleep apnea pose additional challenges. If the airway is not accessible (for example surgeries involving face), these patients are best intubated, even for short procedures. Disturbance of the surgical field (with face surgery) and rapid desaturation in the event of apnea can be eliminated by a secure airway. Intubation difficulties present in this subset of patients create additional problems in an emergency and are best avoided. A STOP-BANG questionnaire might be suitable as a screening tool, both in self-reported and observer evaluated model [27].

Morbidly obese patients have slightly different pharmacokinetics and dosing of both propofol and opioids should take this into consideration [28–30]. However, no system can predict the behavior of these drugs with accuracy. As a result, factors such as the patient’s clinical condition, comorbidity, and the response of various physiological variables to anesthetic drugs should dictate the dosing of intravenous anesthetic agents, rather than any calculated or actual body weight.

Newer sedatives like dexmedetomidine can be employed for some of the office based cosmetic procedures. Absence of significant respiratory depression is a major advantage. Similarly, ketamine is a good choice in selected patients and has additional benefits in decreasing the incidence of respiratory depression. It is popular as “ketofol,” a mixture of ketamine and propofol for an infusion. However, such a mixture is not Food and Drug Administration (FDA) approved. Moreover, the stability of the mixture and its effect on the pharmacokinetics is unknown.

Remimazolam is likely to overcome many of the drawbacks of both propofol and midazolam. It combines the properties of two unique and established drugs in anesthesia, namely midazolam and remiefentanil. It produces hypnosis by binding to GABA receptors (like midazolam) and has organ-independent metabolism (like remifentanil). It is likely to be the sedative/hypnotic of the future, as evidence by the published studies [31, 32]. It has potential to be used as a sedative for procedural sedation. Unlike many rapidly acting intravenous sedatives presently available, the propensity to cause apnea is very low. Availability of a specific antagonist (flumazenil) is a major safety benefit [33].

Hypoxia during or after surgeries involving liposuction can be caused by fat embolism [39–41]. Fat embolism is primarily a mechanical blockage of the vascular lumen by circulating fat globules. It typically presents with symptoms referable to the respiratory system. However, fat globules can also block the circulation to the central nervous system, retina, and skin. With regards to its occurrence during liposuction, most of the reported evidence is in the form of case reports. As it is an uncommon complication, a certain degree of suspicion is necessary. The clinical signs and symptoms can manifest even 2–3 days after the procedure. The obvious other diagnoses that need to be considered are pulmonary infection, pulmonary embolism and aspiration of gastric contents. The classic fat embolism syndrome is defined by the presence of two of three clinical findings including petechial rash, pulmonary distress, and mental disturbances within the first 48 h after the inciting event. Common signs include hypoxia, fever, tachycardia, and tachypnea with bilateral radiographic changes and urinary changes. The presentation is very similar to acute respiratory distress syndrome and the condition carries a high mortality of approximately 10–15 % [42, 43]. The treatment is largely supportive.