**6. Anesthesia management**

should be done replacing the adrenaline with other options such as 1-ornithine-8-vasopressin in concentrations of 0.01 IU/ml, with the disadvantage of having to use it in unheated solution

Although it is well established that liposuction is not a treatment for obesity, more often than desired, the obese patient is programed for this type of procedure, and there are usually other associated comorbidities such as high blood pressure, diabetes mellitus, metabolic syndrome, ischemic heart disease, DVT, and obstructive sleep apnea. If despite recognizing that liposuction is not a reasonable treatment for obesity, if in any case it is decided to do this procedure, the minimum required is that, in the case of hypertension and diabetes, these conditions should be well controlled (it is advisable to postpone patients who have recently changed medications or doses in order to avoid unpleasant outcomes). If the risk of DVT, consider pharmacological thromboprophylaxis apart from mechanical prophylactic

It is common that this type of patients is using recognized or unrecognized (natural remedies) medications and "herbal aids" to lose weight. This type of drugs ranges from amphetamines, thyroid hormones and ephedrine and a fairly large list of herbs and teas that if we take the care to inquire about it (identify them and look for their pharmacological effects), we will find that at least they alter the coagulation system or facilitate the interactions with epinephrine (see Chapter 1). Therefore, the patient should be instructed to suspend all this type of medications and naturopathic remedies at least 2 weeks before surgery. Needless to say, it is

With regard to laboratory tests, in our work center, it seems that it is exaggerated, but the type of patients and the procedures that are carried out have led us to request complete blood chemistry, basic metabolic panel, quantification of glycosylated hemoglobin (if the patient is diabetic), thyroid profile, coagulation times, liver function tests, pregnancy detection, serological detection of hepatitis A, B, and C, as well as detection of antibodies against HIV. If the patient presents some suspicious data, antidoping is added. All patients, regardless of their

The preanesthetic medication in this group of patients is an important part of the preoperative management and should include not only sedative and hypnotic drugs but also an effective scheme that prevents the possibility of emesis and postoperative pain with neuropathic characteristics, which is secondary to multiple nervous fiber trauma of medium and small caliber. A typical preanesthetic scheme is lorazepam, dexamethasone, ondansetron, gabapentin, or

pregabalin. A nonsteroidal anti-inflammatory analgesic can be added.

with the consequent hypothermia of the patient.

76 Anesthesia Topics for Plastic and Reconstructive Surgery

a contraindicated procedure in cocaine addicts.

**4. Preoperative evaluation**

measures.

age, undergo ECG [6].

**5. Preanesthetic medication**

While liposuction of large volumes can be done with any anesthesia technique, we strongly recommend the use of general anesthesia. The anesthetic induction is done in the usual way, being propofol the most used drug. For muscular relaxation for endotracheal intubation, a non-depolarizing drug with rapid action such as rocuronium or atracurium, although vecuronium is probably the most used muscle relaxants due to its safety and low cost. For the maintenance of anesthesia, desflurane, sevoflurane or isoflurane alone or in combination with opioids can be used. Ketofol have been recommended by several authors. Muscle relaxation is optional during the surgery.

In our experience, which is worth taking into consideration, since in the last 8 years, we have accumulated an average of 200 large-volume liposuctions per year (with the peculiarity that it is the same surgeon and the same anesthesiologist). We usually premedicate patients with ranitidine, metoclopramide, ondansetron, and the prophylactic antibiotic of the surgeon's choice. Induction is with fentanyl 3–4 mμ/kg and vecuronium to facilitate orotracheal intubation (usually 4–6 mg) and propofol 2 mg/kg. We continue with inhalatory anesthesia with low flows, in general terms only use oxygen 350 to maximum 400 mL/minute, and desflurane given its faster response to modify the desired CAM. As approximately 60–70% of the time, the procedure will be done with the patient facing down, more when it includes lipoinjection in the buttocks. The patient is intubated orotracheally with a spiral reinforced cuffed tracheal tube (like Sheridan Spiral-Flex®) properly fixed. We never relied on a laryngeal mask; no matter the discussion, it will never approach the security provided by an endotracheal tube. Due to the situation of changes in the patient's position, experience is necessary in turning the patient from supine to the ventral position and ventral to the supine, protecting the cervical spine and ensuring that the endotracheal tube does not move. It is necessary to have protection devices for pressure points, which allows us to keep the patient upside down, taking care of pressure points on the nose and eyes fundamentally (**Figure 4**) [16].

The patient scheduled for liposuction at least qualifies as a moderate thromboembolic risk, so all of them must have compression stockings and intermittent pneumatic compression systems installed, both during surgery and during all the time that they remain in the clinic or at least until they start ambulation. In special cases of higher risk, pharmacological thromboprophylaxis with low-molecular-weight heparin is necessary.

As for the monitoring equipment, beyond the required pulse oximetry, ECG with automated analysis of the ST segment, noninvasive blood pressure measurement every 5 minutes, capnography, and analysis of inhaled and exhaled gases, if available. As for temperature monitoring is useful to keep the record in two channels, central and peripheral temperature, since the isolated reading of the peripheral is of little use, it is more advisable to have both readings and be aware of the gap between the two. Although we have neuromuscular relaxation monitor, given the type of surgery, the low doses of the neuromuscular blocking agents injected for the tracheal intubation and its pharmacokinetic profile, at the end of the surgery, have no residual effects. BIS or entropy monitor can be very useful, given that the hemodynamic variations of the patients are not rare as a result of the adrenergic stimuli due to the infiltrated

these patients, in which their thoracic dynamics differ with just the change to ventral position. Normally, we ventilate the patients with volume-controlled mode, calculating their tidal volume between 6 and 7 mL/kg, and always keep a sequential record of the peak pressure reached with these volumes. In many patients, with only the change to ventral position, the peak pressure

pleted either from the back or the abdomen. The vast majority of patients tolerate it adequately, but between 5 and 10% present a peak pressure increase that forces us to consider that all the extra effort that the ventilator is generating is what helps meet those required volumes. A patient with upper spinal block, in ventral position, sedated and with a nasal cannula, definitely cannot meet the required ventilatory work. Sometimes it is better to change to a pressure-controlled

adequate alveolar ventilation without the significant increase in airway pressure that can be

As mentioned before, it is mandatory to supervise the cumulative dose of lidocaine to avoid systemic toxicity; it must be taken in mind that although it is being used within the limits recommended as safe, it must be considered that its enzymatic metabolism depends on cytochrome P450, which is also responsible for the metabolism of other drugs. This could cause the 3A4 subfamily of cytochrome P450 to be saturated and alter the metabolism of lidocaine. Midazolam competes in its metabolism in this subgroup, which could decrease the elimination of lidocaine, and with its effects, midazolam may mask the toxicity symptoms of lidocaine up until the onset of cardiovascular collapse. Other drugs that inhibit the 3A4 subfamily of cytochrome P450 are listed in **Table 2** [17, 18]. As it is observed, the list is quite extensive, making it difficult to have in mind all these possible interactions, the reason why we recommend the online use of the system of detection of interactions and undesirable side

**Figure 6.** Observe the adequate anesthetic depth (entropy readings) despite the rise in blood pressure secondary to

O, values that increase even more when the tumescence is com-

Anesthesia Management for Large-Volume Liposuction http://dx.doi.org/10.5772/intechopen.83630

O, but always observing the expi-

ET, maintaining

79

increases between 2 and 4 cm H2

effects "epocartes."

epinephrine infiltration.

mode, usually lowering to maximum pressures of 18–20 cm H2

generated in volume-controlled mode (**Figures 6** and **7**).

ratory volume, so that it is sufficient to maintain an adequate reading of CO<sup>2</sup>

**Figure 4.** Proper mechanical thromboprophylaxis by compression stockings and intermittent pneumatic compression system in lower limbs.

**Figure 5.** Hyperemia is seen in the areas of the face where the device for protecting the nose and eyes rested, as well as adequate eye occlusion.

epinephrine and that they do not necessarily have to do with the need of changing the anesthetic depth (**Figure 5**).

One of the reasons to use general anesthesia is because through endotracheal intubation and mechanical ventilation, it is easy to control the respiratory function more efficiently. In this sense, spirometry has great importance. If you do not use spirometry with these types of procedures, you could say that you ventilate blindly, considering the almost obliged obesity of many of these patients, in which their thoracic dynamics differ with just the change to ventral position. Normally, we ventilate the patients with volume-controlled mode, calculating their tidal volume between 6 and 7 mL/kg, and always keep a sequential record of the peak pressure reached with these volumes. In many patients, with only the change to ventral position, the peak pressure increases between 2 and 4 cm H2 O, values that increase even more when the tumescence is completed either from the back or the abdomen. The vast majority of patients tolerate it adequately, but between 5 and 10% present a peak pressure increase that forces us to consider that all the extra effort that the ventilator is generating is what helps meet those required volumes. A patient with upper spinal block, in ventral position, sedated and with a nasal cannula, definitely cannot meet the required ventilatory work. Sometimes it is better to change to a pressure-controlled mode, usually lowering to maximum pressures of 18–20 cm H2 O, but always observing the expiratory volume, so that it is sufficient to maintain an adequate reading of CO<sup>2</sup> ET, maintaining adequate alveolar ventilation without the significant increase in airway pressure that can be generated in volume-controlled mode (**Figures 6** and **7**).

As mentioned before, it is mandatory to supervise the cumulative dose of lidocaine to avoid systemic toxicity; it must be taken in mind that although it is being used within the limits recommended as safe, it must be considered that its enzymatic metabolism depends on cytochrome P450, which is also responsible for the metabolism of other drugs. This could cause the 3A4 subfamily of cytochrome P450 to be saturated and alter the metabolism of lidocaine. Midazolam competes in its metabolism in this subgroup, which could decrease the elimination of lidocaine, and with its effects, midazolam may mask the toxicity symptoms of lidocaine up until the onset of cardiovascular collapse. Other drugs that inhibit the 3A4 subfamily of cytochrome P450 are listed in **Table 2** [17, 18]. As it is observed, the list is quite extensive, making it difficult to have in mind all these possible interactions, the reason why we recommend the online use of the system of detection of interactions and undesirable side effects "epocartes."


**Figure 5.** Hyperemia is seen in the areas of the face where the device for protecting the nose and eyes rested, as well as

**Figure 4.** Proper mechanical thromboprophylaxis by compression stockings and intermittent pneumatic compression

epinephrine and that they do not necessarily have to do with the need of changing the anes-

One of the reasons to use general anesthesia is because through endotracheal intubation and mechanical ventilation, it is easy to control the respiratory function more efficiently. In this sense, spirometry has great importance. If you do not use spirometry with these types of procedures, you could say that you ventilate blindly, considering the almost obliged obesity of many of

adequate eye occlusion.

system in lower limbs.

78 Anesthesia Topics for Plastic and Reconstructive Surgery

thetic depth (**Figure 5**).

**Figure 6.** Observe the adequate anesthetic depth (entropy readings) despite the rise in blood pressure secondary to epinephrine infiltration.

**7. Management of perioperative intravenous fluids**

part of the fluids administered to the patient.

**8. Risks and complications**

possible contraindications are mentioned:

• Liposuction of large volumes with a second procedure

• Multiple procedures including abdominoplasty

• Anticipated blood loss >500 mL in adults

• Liposuction >5 liters

• Tumescent solution >5 liters

• Duration of surgery >6 h

loid solutions from 0.1 to 0.25 mL per mL of aspirate [21, 22].

For safety reasons, tumescent liposuction of large volumes is a surgery in which patients must stay at least 1 night hospitalized in an environment that guarantees their monitoring and safety. Often, there are patients who want extensive liposuction that can be as much as 30% of their total body surface, the remaining 70% will stay on the infiltrated tissues, and from there it will be reabsorbed, with the potential for fluid overload. Although the perioperative management of liquids during liposuction remains an unresolved controversy, especially in liposuction of large volumes, the current trend is to decrease the administration of liquids and

Anesthesia Management for Large-Volume Liposuction http://dx.doi.org/10.5772/intechopen.83630 81

A recent study was done in China by Wang et al. [19], who retrospectively reviewed 83 medical records of patients who underwent extensive liposuction under intravenous monitored sedation with propofol 1–2 mg/kg/h and remifentanil 1–7 μg/kg/h. The intraoperative fluid ratio was 1.66 for extensive liposuction. These authors did not find cases of pulmonary edema, congestive heart failure, or other important complications. The average diuresis in the operating room, the recovery room, and in the surgical floors was 1.35, 2.3, and 1.4 mL/kg/h, respectively. The administration of intravenous fluids during liposuction decreased approximately 300–500 mL. The total volume of intravenous injection was also reduced to less than 1500 mL when the patient was in the recovery room and on the floor of the hospital. The Colombian Consensus recommends to consider the effect of dermoclysis of the tumescent solutions that are injected to the patients [20]. The liposuction removes approximately 30% of the infused tumescent solution, so for each liter of infiltrated tumescent solution, 700 mL are absorbed, so they should be considered as

Another piece of information that can be used as a guide is to administer intravenous crystal-

Liposuction risks and complications are undervalued and underreported. When analyzing the medical literature related to the subject, it is always necessary to take into consideration the context from which the experiences are taken, since it is very different to perform liposuction of low volumes than liposuction of high volumes. In this way, there are interesting publications [23] but refer to cosmetic surgery performed in the office, for which the following

sodium to avoid fluid overload, pulmonary edema, and congestive heart failure.

**Figure 7.** Increase of blood pressure during the infiltration of the solution for tumescence in a hypertensive patient. In the upper part of the figure in yellow, we can see the current loop of spirometry, produced by the decrease in thoracic compliance, compared with the reference white loop before infiltration.


**Table 2.** Drugs that inhibit the 3A4 subfamily of cytochrome P450.
