Disclosure
More than 50% of the adult population in the United States is overweight. Although liposuction is not considered a treatment for obesity, not surprisingly, it has become the most frequently performed cosmetic surgery procedure in the country. Liposuction has evolved over the last 15 years, with the introduction of tumescent and superwet techniques, ultrasonic liposuction, and power-assisted liposuction. These advances have made the removal of larger volumes of fat with less blood loss easier. However, large volume liposuction is a more complex and physiologically different procedure than traditional liposuction, in which small volumes of fat are removed. Unfortunately, the increasing number of potential patients makes it relatively easy for inadequately trained or inexperienced physicians to encounter disastrous complications or even death when performing large volume liposuction. Conversely, experience has shown that when properly trained surgeons perform large volume liposuction under ideal conditions, it is a safe and effective procedure for removing excess fat with low complication and morbidity rates. The definition of “large volume liposuction” varies in the plastic surgery literature. In fact, no strict definition exists and the term is somewhat arbitrary. The most common definitions refer to either total fat removed during the procedure (eg, 4 L of fat removal) or total volume removed during the procedure (fat plus wetting solution, eg, 5 L of total volume removal). Because many of the complications associated with large volume liposuction are related to fluid shifts and fluid balance, classifying the procedure as large volume based on the total volume removed from the patient, including fat, wetting solution, and blood, makes more sense. Large volume liposuction, as most plastic surgeons refer to the procedure, is defined as the removal of more than 5 L of total volume from the patient. To minimize the risk of death and disastrous complication during large volume liposuction, 5 pillars of safety must be strictly adhered to.
Deviation from any one of these pillars can lead to serious complications or death of the patient.
Careful patient selection is extremely critical in large volume liposuction. Many overweight patients may be poor candidates for the procedure for either physiologic and/or psychological reasons. Failure to exclude these patients can lead to both clinical and aesthetic disasters and unhappy patients.
General endotracheal anesthesia administered by a board-certified anesthesiologist is the preferred method of anesthesia for large volume liposuction. A balanced anesthetic consisting of narcotic, midazolam, propofol, and an inhalational agent is used for most patients. Intraoperative monitoring includes noninvasive blood pressure monitoring, ECG, pulse oximetry, temperature, end-tidal carbon dioxide measurements, and monitoring of urine output with Foley catheter in all patients. Continuous communication between the surgeon and anesthesiologist is essential to avoid problems. Constant monitoring of the patient's fluid balance also is essential. The anesthesiologist should be provided with a running balance of wetting solution infused, fat and saline aspirated, blood loss, and urine output. Careful monitoring of these variables and of intravenous (IV) fluid gives the anesthesiologist an accurate idea of the patient's fluid balance and should avoid the problem of fluid overload or hypovolemia. Lidocaine has been eliminated from the wetting solution because the patient is under general anesthesia. The use of lidocaine in wetting solution initially was intended to provide analgesia during procedures performed under conscious sedation. The use of even small amounts of local anesthetic (30 mL of 1% lidocaine [Xylocaine] plain per L) can accumulate when 5-10 L or more of fluid are infused. This can present the patient with a lidocaine load of 35 mg/kg or more.
While reports exist describing 35 mg/kg of lidocaine as an acceptable dose for liposuction wetting solution infusion, it introduces an uncontrollable and potentially serious variable in terms of possible lidocaine toxicity. By performing the procedure under general anesthesia, this variable can be eliminated as a potentially disastrous problem.
Postoperative analgesia can be augmented by infusing small volumes of a dilute bupivacaine (Marcaine) and epinephrine solution prior to closure of the access incisions. A single liter of lactated Ringer is mixed with 50 mL of 0.25% plain bupivacaine and 1 mL of epinephrine. This liter of dilute local anesthetic is hand infused with a 60-mL syringe and infusion needle to the treated areas, taking care to distribute no more than 1000 mL to the entire body.
Fluid balance at the end of the procedure is calculated using the residual volume theory. The residual volume is the difference between all fluids received by the patient and the total saline and urine output of the patient. Fluid received includes IV fluid, crystalloid wetting solution, and any infused posttreatment bupivacaine solution. Add these together and then subtract the urine output and the saline portion of the aspirate (do not include the fat). The difference is the residual crystalloid volume that remains in the patient and acts as the fluid resuscitation source for the patient during the postoperative period. Divide this number by the patient's preoperative weight in kilograms to obtain a value in cubic centimeters per kilogram. This number usually is in the range of 90-120 mL/kg.
Healthy patients within this range postoperatively do not exhibit signs of intravascular volume depletion or overload. For this theory to be valid, using appropriate compression garments is essential to minimize fluid sequestration into the tissues, as is closing access incisions to prevent wound drainage.
If patients have a low residual volume (<90 mL/kg) and exhibit evidence of hypovolemia postoperatively, they may be treated with IV fluid resuscitation (500 mL lactated Ringer challenge). Exercise caution in the healthy oliguric patient with normal hemodynamics and a normal-to-high residual volume in the recovery room. The tendency with such patients is to administer an IV fluid bolus to stimulate urine output when in fact they already may be fluid positive.
Positive-pressure ventilation during anesthesia and increased circulating levels of epinephrine may alter renal blood flow and cause oliguria, which can persist postoperatively. Most patients with a residual volume of 90-120 mL/kg begin to diurese on their own shortly after surgery. A small dose of IV furosemide (Lasix; 5 mg) often can stimulate a brisk diuresis in these patients. As with any situation, careful clinical evaluation of the patient and all the available data should be made before embarking on a course of treatment. |
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Large volume liposuction should be performed in either an accredited hospital or at an accredited/certified outpatient ambulatory surgery facility. Furthermore, overnight care and registered nurse observation facilities should be available for all patients, although these are not necessary for everyone. Young healthy patients with no underlying medical problems should recover uneventfully as long as intelligent and competent adult help is available during the entire first 24 hours following surgery. Patients may be admitted for overnight nurse observation and care for a number of reasons, including a history of underlying medical problems (eg, asthma, sleep apnea, cardiovascular or pulmonary problems), lack of competent adult supervision, patient convenience, multiple surgical procedures, or extensive surgical operating room time. Postoperative monitoring during overnight stays should include pulse oximetry, hemodynamic monitoring, and fluid volume status in addition to control of postoperative pain and nausea. Mark patients the day of surgery while they are in the standing position. If prone positioning is anticipated, the patient undergoes induction of general anesthesia on the gurney and then is turned to the prone position. Gel pads are used on the operating room table over the top of a water-heating blanket. This helps minimize heat loss and protects sensitive pressure points (eg, occiput, knees, elbows, heels, iliac crest, breasts, genitals). Take care to avoid traction or pressure on the brachial plexus, ulnar nerve, or other large nerves. Tape the eyes shut after placement of ophthalmic lubrication and place the head on a gel horseshoe headrest to take pressure off the eyes and stabilize the head against liposuction-induced motion. Protection against corneal abrasion is important when the patient is in the prone position and during long procedures. Use gel chest rolls for positioning and immobilization of the patient when in the prone position. Pneumatic compression devices are used for all patients undergoing large volume liposuction. Calf compression devices or the PlexiPulse ankle compression devices may be used. The ankle compression devices are equally as effective as the longer calf compression devices and are particularly useful when the patient is undergoing knee or calf liposuction. Low molecular weight dextran or heparin typically is not used or required during these procedures. Use of the compression devices is continued through the recovery room phase and overnight if the patient is admitted. Otherwise, encourage patients to begin ambulation as soon as possible and instruct them in lower extremity muscle-contracting exercises while they are in bed to minimize the risk of deep venous thrombosis and pulmonary embolus. Attention to body temperature is crucial during large volume liposuction for a number of reasons. Patients are at increased risk of hypothermia due to exposure of large body surface areas, infusion of large volumes of wetting solutions, and long operative procedures. Correction of hypothermia can be difficult once it develops, so prevention is essential. Numerous problems that may occur during surgery (eg, cardiac dysrhythmias, coagulopathies, oliguria, electrolyte imbalances) can be intensified or worsened by hypothermia. Room temperature is monitored carefully, as is esophageal temperature of the patient. In addition to a heating blanket on the bed, a hot air blanket (eg, Bair Hugger type) is used to cover nonsurgical areas during the procedure. As previously mentioned, wetting solution is heated to 90°F in a warming cabinet.
Admit patients undergoing large volume liposuction to the recovery room for approximately 1.5-2 hours for close monitoring of hemodynamics, pulmonary function, and fluid balance. Keep IV rates at TKO unless evidence of hypovolemia exists. A well-trained and competent recovery room staff of registered nurses is essential when providing postoperative care to a patient who has undergone large volume liposuction. The Foley catheter usually is left indwelling overnight for patient convenience and to monitor diuresis. If questions arise concerning the patient's fluid status while in the recovery room, use the residual volume theory and the patient's clinical status to determine whether the patient is hypervolemic or hypovolemic. Most patients who have undergone large volume liposuction should show signs of diuresis before being transferred to an overnight care facility or being discharged home.
Complications in large volume liposuction are the same as with smaller volume liposuctions and other surgical procedures. These can be divided into minor and major complications and are medical or aesthetic in nature. Because patients who have undergone large volume liposuction may have more problems with skin elasticity and redundancy at the start, a higher incidence of aesthetic contour-related problems may exist. Good preoperative patient counseling and declining to operate on poor candidates can minimize these types of complications.
Major complications following large volume liposuction tend to be rare and can be minimized by adhering to the 5 pillars of safety (ie, safe surgeon, safe anesthesiologist, safe facility, safe coworkers, properly selected patient). The incidence of pulmonary embolus, deep venous thrombosis, major infection, penetration injuries, skin or soft tissue necrosis, bleeding, pulmonary edema, hypovolemic shock, fat emboli, drug toxicity (epinephrine or lidocaine), unplanned blood transfusion, and mortality is uniformly low or absent in almost every large series of patients who have undergone large volume liposuction. Physicians who have little or no experience with large volume liposuction or those who do not adhere to the 5 pillars of safety are at significantly higher risk of a patient experiencing a major complication or death following this type of procedure.
Minor complications after large volume liposuction are not uncommon. These include minor aesthetic contour irregularities, prolonged swelling, scar tissue formation, minor wound healing problems, seromas, sensory changes and discomfort, hyperchromia, and blistering of the skin from garment irritation or ultrasonic liposuction. Fortunately, the incidence of these complications decreases significantly with experience.
Large volume liposuction can be performed safely if certain guidelines are followed. Properly selected patients who have a good understanding of the expectations and limitations of the procedure tend to be very satisfied with the results. Importantly, physicians who are considering performing large volume liposuction must understand the physiology and differences from smaller volume liposuction. Applying the same standards and treatment parameters as with small volume liposuction may result in death and disaster.
The 5 pillars of safety must be followed at all times. The surgeon first must be well trained in smaller volume liposuction and have a thorough understanding of the physiologic implications of infusing and suctioning large amounts of fluids from the body. Cases should be scheduled and performed such that incrementally larger volumes of fat are removed as the physician gains experience. The anesthesiologist, present on every case, likewise must have a complete understanding of the procedure and be well trained to handle preoperative, perioperative, or postoperative problems. The facility where the procedure is performed should be accredited, properly equipped, and have experience with large volume liposuction procedures. Overnight care facilities must be available with registered nursing care and the appropriate monitoring equipment. Support staff at every level of the procedure, from the preoperative phase through recovery, must be competent and experienced.
Finally, the patient must be healthy and appropriately selected. Motivation, goals, and expectations must agree with what is clinically possible. Patients should be psychologically stable with good diet and exercise habits or evidence of motivation toward these habits.
In addition to these basic pillars, several other issues are worthy of repeating to ensure a safe outcome. Frequent communication between all members of the surgical team is critical. The tumescent technique of injecting very large volumes of wetting solution must be avoided in large volume liposuction–this invariably leads to fluid overload and its associated problems. Instead, the superwet technique of fluid infiltration, in which volume infused is roughly equal to total volume removed (1:1 ratio), should be practiced. With this in mind, remember that enough wetting solution with epinephrine should be infused to maintain an essentially bloodless aspirate. If the aspirate becomes excessively bloody, reevaluate the procedure. The procedure either should be terminated and/or more wetting solution infused for added hemostatic effect from the epinephrine.
Compressive postoperative garments always are worn to minimize postoperative bleeding, swelling, and third spacing of fluid. Finally, attention must be paid to maintaining the patient's core body temperature using heating blankets on the table, minimizing body exposure, using Bair Hugger-type warming blankets, and using warmed wetting solution.
Ultimately, the long-term results following large volume liposuction depend on the preoperative condition of the patient's skin, the patient's overall health and expectations, and the ability of the patient to maintain a healthy weight and lifestyle postoperatively. Whenever in doubt, consider staging procedures in terms of multiple liposuction procedures or combining the liposuction with other procedures.
For excellent patient education resources, visit eMedicine's Procedures Center. Also, see eMedicine's patient education article Liposuction.
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