LIPOSUCTION TEXTBOOK

Chapter 26:
Tumescent Infiltration Technique

Complete tumescent local anesthesia can be achieved in the vast majority of patients without using systemic anesthesia during infiltration or liposuction.

The term tumescent describes tissue that is swollen and firm. Infiltration with the tumescent technique implies that such a large volume of dilute local anesthetic solution is infiltrated that the targeted tissues become swollen and firm. The goal of tumescent infiltration is to produce 100% anesthesia and profound vasoconstriction with minimal risk of complications, minimal discomfort, and minimal elapsed time.

Tumescent liposuction can be accomplished either totally by local anesthesia or with simultaneous use of systemic anesthesia. Those who use systemic anesthesia often argue that the choice of anesthesia is based on the personal choice of the patient and surgeon. The patient has a choice, however, only if the surgeon or anesthesiologist is skilled in tumescent infiltration. If the clinician cannot produce complete tumescent local anesthesia, the surgeon is forced to rely on systemic anesthesia.

Preliminary Considerations

The prerequisites for training in tumescent infiltration include the following:

1. Modicum of manual dexterity
2. Basic knowledge of subcutaneous anatomy
3. Understanding of abnormal cardiac rhythms
4. Empathetic attitude regarding patients’ anxieties
5. Confidence that complete tumescent local anesthesia should be routine

Continuous monitoring for cardiac rhythm and automatic blood pressure measurements are required. If parenteral sedation or narcotics are given, the patient should be monitored by pulse oximetry.

Registered nurses, surgeons, and anesthesiologists are appropriate candidates for training in the special techniques of tumescent local anesthesia.

Effects of Tumescence

Tumescent infiltration can achieve at least six clinically useful effects, as follows:

1. Subcutaneous pharmacologic reservoir effect
2. Targeted pharmacologic delivery
3. Hydrodissection
4. Hydraulic elevation of tissue
5. Hydraulic magnification of tissues
6. Hydraulic compression

The subcutaneous reservoir effect on lidocaine effectively slows its systemic absorption, thereby prolonging the local anesthetic effect and decreasing the peak plasma concentration and the risk of toxicity. Targeted pharmacologic delivery of epinephrine produces profound vasoconstriction and surgical hemostasis.

Hydrodissection spreads dense fibrous collagenous tissue and permits easier penetration of a microcannula. Hydraulic elevation of tissue removes the deeper layers of fat away from vulnerable subjacent tissues.

Hydraulic magnification of fat tissues facilitates detection and correction of any fat deposits initially missed during liposuction and promotes smoother liposuction results. Hydraulic compression of blood vessels may promote hemostasis.

Alert Patients

A patient who is awake and alert can cooperate and help the clinician achieve complete local anesthesia. Once an area has been completely infiltrated, the clinician can determine the degree of anesthesia by gently probing the area with an infiltrating cannula or spinal needle. If an area of incomplete anesthesia is encountered, the alert patient can inform the clinician, and the indicated area can be given additional infiltration. With this methodical technique, the clinician can consistently achieve complete local anesthesia.

Complete local anesthesia can be more difficult to achieve in a sedated patient. With less attentive, more rapid, and more “time-efficient” infiltration techniques, the ultimate degree of local anesthesia is more likely to be suboptimal. The patient with inadequate local anesthesia will experience surgical pain, will become anxious, and will not tolerate liposuction without significant ancillary sedation and narcotic analgesia or general anesthesia.

Tumescent infiltration under systemic anesthesia tends to be a self-fulfilling process: it often provides incomplete local anesthesia and therefore requires more systemic anesthesia.

Infiltration Cannulas

Based on clinical experience, fibrous septa are associated with more sensory nerve fibers than adipocytes. Reducing the traction on the fibrous septa as a metal tube or probe is passed through subcutaneous fat will reduce the painful stimuli.

Surgeons who rely on systemic anesthesia for liposuction typically use 14-gauge or 12-gauge, blunt-tipped, multiholed infiltrating cannulas to facilitate the maximum rate of tumescent infiltration. In a patient who has received no systemic anesthesia, however, a relatively large blunt-tipped infiltrating cannula causes more pain when passed through fibrous adipose tissue than does a 20-gauge spinal needle. Without systemic anesthesia, it is too painful to use a blunt-tipped cannula to infiltrate the most fibrous areas, such as the back, female and male breasts, male flanks, and epigastric and periumbilical areas of abdomen. In contrast, these areas can be routinely infiltrated without intravenous (IV) sedation or narcotic analgesics by using a spinal needle as the infiltration device.

Infiltrating cannulas with smaller diameters cause less patient discomfort. A 25-gauge pediatric spinal needle causes almost no discomfort when passed through fat and can be used during the initial stages of infiltration if a patient is unusually sensitive or anxious. After using the 25-gauge needle briefly, the tissues are sufficiently anesthetized to permit the use of 20-gauge needle with minimal discomfort.

A 20-gauge spinal needle causes an unpleasant pricking sensation that can be greatly reduced simply by advancing the needle more slowly. Using a 20-gauge spinal needle for the infiltration allows the vast majority of patients to tolerate infiltration easily without parenteral sedation.

The ideal infiltrating cannula slips through the fibrous septa with minimal discomfort to the patient and minimal risk of injury to nerves or blood vessels. A short-bevel spinal needle is designed for puncturing while minimizing the risk of cutting or lacerating tissue. In contrast, a long-bevel hypodermic needle is designed for cutting through the skin and deeper tissues with minimal resistance, but it is more likely to lacerate tissue.

An infiltrating needle that is unnecessarily sharp may lacerate nerves or blood vessels. A cannula tip that is extremely blunt imposes excessive traction on the fibrous tissue as it is pushed through the collagenous septa.

Pain During Infiltration

Infiltration need not be uncomfortable and painful if done with gentleness and care. Gentleness is one of the most essential factors in minimizing discomfort with infiltration. Infiltration that is done too vigorously will be painful and require systemic anesthesia.

The most uncomfortable aspect of tumescent liposuction is the infiltration of the local anesthetic solution. With proper technique in tumescent infiltration, however, the patient should not require parenteral analgesia. After the tumescent infiltration has been accomplished, liposuction should cause little, if any, discomfort.

The degree of discomfort associated with tumescent infiltration increases along with the following:

1. Flow rate of anesthetic solution as it is pumped into adipose tissue
2. Speed at which infiltrating cannula is pushed through adipose tissue
3. Outside diameter of infiltration cannula
4. Bluntness of infiltration cannula tip
5. Speed and delivery of infiltration technique
6. Patient’s anxiety level
7. Patient’s intolerance to discomfort

Those who tolerate the infiltration process most easily are females, older than 40 years of age, and not thin. Mothers seem to be much more tolerant of discomfort than are women who have never given birth.

Body areas that are especially sensitive to the discomfort or pain of infiltration include the periumbilical area, areas near costal margin or overlying ribs, the posterior waist, posterior aspects of lateral thigh, medial knee, and infragluteal crease.

Proper Technique. The mild to moderate pain associated with infiltration can be decreased or eliminated with proper infiltration technique. Less pain results when a spinal needle is pushed through fat while simultaneously infiltrating local anesthetic solution compared with advancing the needle without infiltration. The stream of local anesthetic solution seems to anesthetize the fatty tissue in advance of the needle tip. With experience the clinician can quickly determine the optimal rate for advancing the needle.

Fibrous Tissue. The pain of a metal tube or probe being pushed through fat is associated with the puncturing of the fibrous septa that partition fat. The greater the fibrousness of the adipose tissue, the greater is the degree of discomfort. The upper abdomen, periumbilical area, breasts, upper posterior flanks, and scapular areas are particularly fibrous and therefore may cause discomfort on the initial infiltration.

Medication. With proper technique the vast majority of patients will tolerate tumescent infiltration without parenteral sedation or narcotics. Approximately 96% to 98% of patients should require only minimal oral sedation during infiltration.

Typical preoperative medication consists of oral lorazepam (1 mg) and/or oral clonidine (0.1 mg). Fewer than 3% of patients receive 1 to 2 mg of IV midazolam.

Cannula Insertion. The rapidity with which an infiltrating cannula is pushed through the subcutaneous fat can affect patient comfort. A cannula that is advanced more slowly causes less discomfort. Excessively rapid infiltration or an excessively large cannula requires systemic anesthesia.

Tissue Immobilization. A firm but gentle grip on the target adipose tissue facilitates infiltration. A proper grip immobilizes the collagenous partitions and allows the needle to pass through these sensitive sheets of fibrous tissue with less resistance and less discomfort.

On the other hand, squeezing or pinching the skin and subcutaneous tissue too vigorously can be painful.

Clinical Skills. Tumescent infiltration has two principal goals: complete local anesthesia and profound hemostasis. With systemic anesthesia, any clinician with basic infiltration skills can easily and rapidly achieve sufficient tumescent hemostasis. In contrast, achieving complete local anesthesia without systemic anesthesia requires more advanced skills.

Surgeons who lack training in tumescent infiltration may have difficulty with routine liposuction totally by local anesthesia. Others have stated, “In our experience, the dilute lidocaine used in Klein’s wetting solution provided inadequate intraoperative anesthesia for many patients, even those receiving intravenous sedations.”¹

The volume of tumescent anesthetic solution necessary for surgical anesthesia is twice that necessary to produce adequate hemostasis. Thus surgeons who use tumescence only to achieve hemostasis tend to infiltrate an inadequate volume of tumescent solution, which produces inadequate local anesthesia. These surgeons may not be able to achieve adequate local anesthesia with subcutaneous infiltration.²

Special Training. Learning to master the technique of painless tumescent infiltration and to achieve profound tumescent local anesthesia is not difficult. It cannot be learned, however, simply by reading a set of instructions or a chapter.

Unskilled infiltration can be painful for the patient and usually requires systemic anesthesia. Surgeons compensate for insufficient training by using systemic anesthesia to achieve local anesthesia.

Skillful infiltration and use of microcannulas are the keys to doing liposuction totally by local anesthesia. The surgeon untrained in these two essential techniques will need to use epidural or systemic anesthesia.

Rate of Infiltration

The following two distinct variations exist for tumescent infiltration:

1. Rapid infiltration under general anesthesia
2. Slow to moderate infiltration under minimal oral sedation or intramuscular (IM) sedation

If a variable-rate peristaltic pump is used to deliver the anesthetic solution into the subcutaneous adipose tissue, the rate of infiltration can be adjusted. When the peristaltic pump rate is sufficiently slow, the flow of fluid exiting a 20-gauge spinal needle will appear as discrete pulses of water. As the flow rate is increased, the jet of fluid flows more continuously. A first approximation of the optimal flow rate is the rate at which the pulsatile stream exiting the spinal needle becomes a continuous stream.

If the patient is comfortable, the flow rate can be increased further. The flow rate only needs to be reduced in areas that require a more precise infiltration, such as the submental chin, face, neck, or ankle areas.

Rapid Versus Slow Approach

The more rapid the rate of tumescent infiltration, the more painful the process becomes and the greater the requirement for parenteral sedation and narcotic analgesia.³ Other than requiring systemic anesthesia, rapid infiltration of dilute tumescent solutions is generally safe, but the resulting local anesthesia tends to be incomplete and often requires heavy IV sedation or general anesthesia.

If the infiltration is extremely rapid, it tends to be less uniform. Unevenly distributed anesthetic solution might provide adequate hemostasis, but the degree of hemostasis is not optimal. Under general anesthesia the completeness of local anesthesia is not relevant during surgery, but postoperative analgesia may be less complete after rapid infiltration.

Incomplete and “patchy” tumescent infiltration may predispose to liposuction results that are lumpy and uneven.

Rapid infiltration under general anesthesia or heavy IV sedation requires less skill and less time. The convenience of rapid infiltration, however, must be weighed against the risks of the anesthesia and a tendency toward uneven aesthetic results.

Lidocaine Concentration. For commercial out-of-the-bottle concentrations of lidocaine (1% = 10 g/L) and epinephrine (1:100,000 = 10 mg/L), the faster the rate of infiltration, the greater the peak plasma lidocaine levels. In contrast, no evidence indicates that rapid infiltration of dilute tumescent lidocaine will produce significantly higher peak plasma lidocaine concentrations than slow infiltration.

The rate of tumescent infiltration and the maximum tissue pressure during the injection of dilute lidocaine (0.1%) do not affect the rate of lidocaine absorption.⁴ The occurrence of peak plasma lidocaine concentration is significantly delayed by the epinephrine in the tumescent anesthetic solution.

Optimal Results. Optimal tumescent anesthesia is synonymous with complete local anesthesia and profound hemostasis. Rapid infiltration typically produces less than optimal tumescent anesthesia. The clinician whose goal is to achieve accurate, painless, and complete tumescent anesthesia will usually achieve superior results compared with one whose priority is speed rather than accuracy and completeness.

Optimal tumescent infiltration into fibrous fat requires deliberate attention to detail. For example, the periumbilical area is more fibrous than the surrounding fat and requires slower infiltration than adjacent areas. In less fibrous areas, slow rates of infiltration are not as necessary.

Initiation of Infiltration

Intradermal Blebs

To anesthetize skin sites where the infiltrating spinal needle will be inserted, the tumescent anesthetic solution is injected intradermally in small blebs. This intradermal local anesthesia is exactly the same dilute solution that is injected into fat.

Using a 30-gauge needle on a 6-ml syringe, these intradermal injections are usually the most painful part of the entire tumescent liposuction procedure. The degree of this pain varies for different patients, as well as for different sites on the same patient. Warning patients about increased stinging in certain areas also allays anxiety.

The least painful injection technique stretches the skin taut with two fingers of one hand while the other hand holds the syringe with a sharp 30-gauge needle that is inserted at a 45-degree angle into the superficial dermis. The 30-gauge needle must be replaced when it becomes dull after 15 to 30 injections.

Deep Infiltration

Tumescent infiltration should be initiated in the deepest planes of a targeted fat compartment, not in a superficial layer of fat. Commencing infiltration too superficially creates a superficial plane of firm induration within the fat, which makes it difficult to palpate the interface between the deepest layer of fat and muscle.

Starting the infiltration too superficially also obscures the deeper planes and impedes complete anesthesia. Clinicians tend not to infiltrate more deeply than the initial plane of tumescence. Any uncertainty about the depth of the targeted fat compartment may predispose to inadequate deep anesthesia and may impair optimal liposuction.

By first infiltrating along the deepest layer of fat, the more superficial layers are partially anesthetized. The patient will then experience less pain when the superficial layers are infiltrated later (Figure 26-1).

Complete Anesthesia

For painless liposuction totally by local anesthesia, virtually every cubic centimeter of adipose tissue must come into direct physical contact with the anesthetic solution. In contrast, achieving adequate tumescent hemostasis does not require such complete infiltration. When anesthesia for liposuction relies on general anesthesia, and if the tumescent technique is used principally for its hemostatic effect, achieving a maximum degree of tumescence is not essential.²

With meticulous infiltration that delivers tumescent anesthesia throughout the fat, surgical blood loss is minimal, with less than 10 ml of whole blood per liter of aspirated supranatant fatty tissue (1% or less).⁵ A compulsive, methodical, relatively slow infiltration not only achieves complete anesthesia but also yields an aspirate containing approximately 1% whole blood.

A rapid tumescent infiltration yields an aspirate containing 7% whole blood. For example, in one series of 107 patients who had liposuction under general anesthesia with rapid tumescent infiltration, the estimated blood loss was 73 ml of whole blood per liter of aspirate (supranatant plus infranatant).⁶

Three liters of an aspirate with 1% blood contains 30 ml of whole blood, and an equal volume of an aspirate of 7% whole blood contains 270 ml of whole blood. Neither situation requires a transfusion. Thus, if systemic anesthesia is used without concern about optimal local anesthesia, no significant clinical difference exists between a methodical or a rapid tumescent infiltration.

Patient Comfort

To minimize the discomfort of infiltration, a generous volume is injected in a steady stream of anesthetic solution while the needle is advanced at a slow and uniform rate along the deepest plane within the fat compartment.

If it is the patient’s first experience with tumescent infiltration, the first area treated should be a location that is less sensitive (e.g., hips instead of flanks).

Another means of minimizing the discomfort during the initial infiltration is to insert the needle slowly to its full extent, then infiltrate a generous volume while slowly withdrawing the needle.

Infiltration Patterns. The infiltrating needle is advanced smoothly through the targeted tissues. To avoid leaving nonanesthetized areas in any portion of the targeted fat, it is important to direct the infiltration needle in a specific fanlike pattern radiating from each insertion site. Fanlike patterns of infiltration should overlap like tiles on a roof. Beginning along the deepest plane within the fat, the infiltration needle should follow these patterns within the middle and superficial planes (Figure 26-2).

The number of planes infiltrated depends on the thickness of the targeted compartment of fat. Adjacent fanlike patterns should overlap as they radiate from different intradermally anesthetized blebs. The overlapping fans should cover the entire targeted area.

During infiltration, clinicians should pay close attention to any areas of discomfort. These areas will likely require infiltration of extra anesthetic solution. Superficial areas that are not blanched (not etiolated) might require additional infiltration.

Firm Approach. A firm grip is required to lift the tissues as the infiltration needle is aimed at the deepest plane. To avoid an inadvertent puncture of tissues that are deep to fat, the needle’s path should be in a plane that is tangential to the deep muscle fascia.

Short fingernails are required to obtain a firm grip on the deepest fat and lift it away from muscle.

Follow-up Checks. After infiltration from the deep to superficial plane, the clinician can check the completeness of local anesthesia by inserting the needle into the targeted fat and moving it in and out from one side of the targeted area to the other. Random checks are made deeply and superficially for “hot spots” caused by insufficient anesthesia. The patient should inform the physician if sensitive areas are encountered (Box 26-1).

Intraoperative Infiltration

If the patient experiences tenderness or discomfort during the surgery, additional anesthetic solution should be injected into the affected area. The infiltration technique is modified to compensate for the existence of tunnels created by liposuction. The tissue must be gripped in a firm but gentle manner to occlude the tunnels during infiltration.

After liposuction has been initiated in an area, the preferred infiltration cannula for adding anesthetic solution to an insufficiently anesthetized area is either a 20-gauge spinal needle (8 cm) or a long 18-gauge intradiscal needle (15 cm). A blunt-tip infiltrating cannula is less effective because of its tendency to follow the path of preexisting tunnels.

The concentration of lidocaine used for intraoperative infiltration can vary depending on the clinical situation. Frequently a concentration of 500 mg/L of lidocaine and 0.5 mg/L of epinephrine is sufficient.

Volume of Infiltration

The appropriate volume of tumescent anesthetic solution for any given volume of targeted fat is the minimal volume that will achieve complete local anesthesia. The ratio of the optimal volume of tumescent solution to the volume of the entire fat compartment is not a fixed number. Similarly, the ratio of the volume of the tumescent solution to volume of aspirated fat varies widely.

Subcutaneous fat occupies a space that can accommodate an additional volume of fluid that is approximately twice the volume of the subcutaneous fat. Tissue tumescence is therefore typically achieved by infiltrating a volume of fluid that is approximately two times the volume of the targeted subcutaneous fat.

Because it is not the goal of liposuction to remove all the fat from any area, the volume of aspirated fat will be less than the total volume of fat within any targeted compartment. Thus the ratio of the volume of tumescent anesthesia to aspirated fat is often, but not always, in the range of 2:1 or 3:1 (tumescent fluid/aspirated fat). Patients who were very obese and then lost weight are exceptions to this generalization.

Obesity causes the skin and subcutaneous fascia to be permanently stretched. With subsequent weight loss, the skin and subcutaneous interstitial tissues remain stretched and capacious. On infiltration of tumescent local anesthesia, a greater volume of tumescent solution is required to achieve tumescence.

In patients who weigh much less than their maximum weight, producing complete tumescence is not always necessary to achieve adequate local anesthesia and hemostasis. The clinician should avoid infiltrating unnecessarily large volumes in these patients with “flabby fat.”

Bulk Flow of Anesthetic Solution

A sufficient volume of anesthetic solution is important for achieving adequate local anesthesia. A large volume of solution facilitates the spread of local anesthesia by bulk flow throughout the subcutaneous tissue.⁷

Bulk flow is a mechanical process involving hydrodissection and the movement of a volume of liquid en masse throughout the subcutaneous fat compartment. Bulk flow can occur rapidly under elevated hydrostatic pressure produced by an injection pump. It also occurs more slowly from the elastic recoil of the fascial tissues acting on a subcutaneous bolus of injected fluid or from the effects of gravity.

In contrast, diffusion is a small-scale chemical process whereby lidocaine molecules move across a relatively short distance after bulk flow has pushed a solution containing lidocaine to within a short distance of a sensory nerve.

Bulk flow is responsible for the delivery of lidocaine on a large scale throughout the entire fat compartment. A solution of local anesthetic spreads through subcutaneous tissue by bulk flow through the interstitial gel substance, dissecting along anatomic planes and along the lamellae of fibrous septa within adipose tissue (Figure 26-3).

Table 26-1 lists approximate volumes of tumescent anesthetic solution required for various body areas.

Peau d’Orange Appearance

Peau d’orange (French, “orange-peel”) refers to a characteristic pitted appearance of the skin of an orange. The subcutaneous infiltration of a sufficiently large volume of tumescent local anesthesia produces a fine, dimpled appearance of the skin texture that resembles the skin of an orange.

The peau d’orange appearance is the result of intradermal swelling everywhere except around pilosebaceous hair follicles, which prevent expansion because of their relative inelasticity. Tumescent infiltration can cause peau d’orange skin by extreme hydration of the dermis after superficial subcutaneous injection of a crystalloid solution such as 0.9% normal saline or lactated Ringer’s solution.

Although peau d’orange skin is one possible end point of tumescent infiltration, this appearance is not necessary to achieve complete tumescent local anesthesia. Good vasoconstriction and sufficient local anesthesia can be achieved without the tumescent infiltration producing peau d’orange skin. If the infiltration is only superficial, however, the clinician can produce a peau d’orange appearance without complete local anesthesia. In most patients, provided that the infiltration has been initiated in the deepest plane, tumescent infiltration that produces peau d’orange appearance is usually a reliable sign of complete local anesthesia.

In other words, tumescent infiltration to the point of producing peau d’orange skin is usually sufficient, but not always necessary, to produce complete local anesthesia and profound tumescent vasoconstriction.

Avoidance of Excessive Volumes

The optimal volume for tumescent anesthesia is not precisely defined. Some care and experience are required to determine the safest and most effective volume of solution. Maximum tumescence is not required to produce profound capillary vasoconstriction. Thorough, uniform tumescence is necessary, however, to optimize the local anesthesia.

Clinicians should avoid infiltrating an excessive volume of tumescent solution. Too much fluid volume in the subcutaneous fat results in tediously inefficient, unnecessarily slow and difficult liposuction. In some patients, excessive subcutaneous infiltration of isotonic fluid can predipose to hemodilution and produce prolonged edema of the lower extremities.

An excessively large volume of tumescent fluid infiltrated into the subcutaneous fat of the abdomen may be uncomfortable for the patient and may impede liposuction. No advantage is gained by infiltrating 5 L of excessively dilute tumescent solution at 500 mg of lidocaine/L when 2 L of 1250 mg of lidocaine/L is more comfortable, is safer, and facilitates more effective abdominal liposuction.

An excessive volume of tumescent isotonic fluid can be dangerous. Subcutaneous tumescent fluid in the abdomen that greatly exceeds the amount necessary to achieve local anesthesia can impair diaphragmatic expansion and limit respiratory ventilation.

Symmetric areas of the body should receive approximately equal volumes of tumescent anesthetic solution. Unless the patient displays obvious asymmetry preoperatively, the goal is to infiltrate equal volumes of anesthetic solution into each side of paired areas, such as both hips or symmetric portions of both thighs.

Technique for Facial Resurfacing

Tumescent infiltration of the entire face can provide excellent anesthesia for full-face carbon dioxide (CO₂) laser resurfacing, without using systemic anesthesia.

Preoperative medications, given at least 15 to 30 minutes before infiltration, include oral lorazepam (2 mg) and clonidine (0.1 mg). Although IV sedation is usually not necessary, an occasional patient will require midazolam (1 to 2 mg) just before infiltration.

The formulation for tumescent anesthetic solution in CO₂ laser resurfacing is 600 mg of lidocaine, 1.0 mg of epinephrine, and 5 mEq of bicarbonate in 250 ml of physiologic saline (0.9% NaCl). This anesthetic solution, when appropriately infiltrated, should provide complete anesthesia for the entire face for up to 1 hour of CO₂ laser resurfacing. The infiltration typically requires about 45 minutes (range 35 to 60 minutes).

Infiltration Sequence

The superficial subcutaneous infiltration of the central portion of the face, including the periorbital, nasal, and labial areas, is accomplished with the use of hand-held syringes by a well-trained physician or registered nurse. The equipment usually consists of two 6-ml syringes with a 1.25-cm (½-inch) or 2.5-cm (1-inch) 30-gauge needle, depending on the area being infiltrated, and two 12-ml syringes with a 5-cm (2-inch) 25-gauge needle. Having an assistant to refill the syringes is very helpful.

In some patients a peristaltic pump can be used to help infiltrate the lateral portions of the face over the mandible and submental areas. A peristaltic pump should not be used around the eyes, lips, and delicate mid facial structures. After topical anesthesia of the cornea, stainless-steel eye shields are placed before initiating the tumescent infiltration.

An initial ring of tumescent anesthesia is infiltrated from the glabella, across the cheeks, and onto the submental chin. The initial injection is extended over the eyebrows by alternating the injections between left and right. Past the lateral brow, the bead of tumescent infiltration is continued past the lateral canthus, using a 0.5-cm 30-gauge needle on a 6-ml syringe. Next, using a 25-gauge 5-cm needle on a 12-ml syringe, the paths of tumescent infiltration are extended onto the cheeks, past the lateral oral commissure, and over the mandibular margin, meeting on the submental chin.

This initial ring of tumescent anesthesia produces a superciliary nerve block for anesthesia of the entire forehead. The ring also provides a path of anesthetized skin through which needles can be painlessly inserted to anesthetize the lateral and medial portions of the face.

Anatomic Considerations. Anesthetizing the medial cheeks and chin results in some anesthesia of the lips, which subsequently can be infiltrated with less discomfort. The nose is anesthetized with tumescent infiltration extending from the glabella, along the nasal dorsum to the tip and columella, and then laterally.

The upper and lower lids must be anesthetized with special care. The needle must never be held pointing toward the globe. After raising a bleb of tumescent anesthesia at the lateral canthus, the tumescent anesthesia is injected and caused to flow medially by bulk flow, aided by direct pressure from the surgeon’s fingers. The anesthesia is extended medially by inserting the needle superficially through the thin skin that is already tumescent.

The left hand should rest on the patient’s face, with the right hand holding the syringe and resting on the left hand. By moving the syringe and needle in concert with the patient’s face, this technique minimizes the risk of ocular injury from the needle should the patient suddenly jerk the head.

Infiltration of the eyelids and face demands careful attention to avoid trauma to vulnerable structures. Tumescent infiltration to provide full-face local anesthesia for CO₂ laser resurfacing is best attempted after observing the procedure performed by an expert.

Patient Anxiety

Anxiety greatly influences how the patient perceives discomfort and pain. A skillful clinician can help relieve a patient’s anxieties by insightful communication and, when necessary, conservative use of drugs.

Patients vary greatly in their ability to tolerate discomfort. Some patients tolerate the discomfort of rapid tumescent infiltration without complaint. Others complain that the blood pressure cuff is too tight or when anesthetic solution drips and trickles over their skin. Much of this variability is associated with the patient’s anxiety.

Preoperative Relief

In most cases a patient’s anxiety is mild to moderate and entirely appropriate to a preoperative situation. This type of anxiety is most effectively treated with a confident and empathetic “bedside manner.”

The surgeon and staff can allay the normal preoperative anxiety with patience and gentleness. Compassionate interpersonal skills with thoughtfulness and a caring attitude, as well as clinical experience, are indispensable prerequisites in caring for awake patients under local anesthesia. Surgeons who do not cultivate these skills may be unable to accomplish liposuction totally by local anesthesia.

For example, at the time of preoperative laboratory tests, the site of the phlebotomy needle puncture is anesthetized using a 30-gauge needle to inject an intradermal bleb of neutralized lidocaine. Afterward, patients typically comment that it was the least painful “blood test” they ever experienced. They begin to believe that local anesthesia can be painless. On the day of surgery, the IV catheter site is also anesthetized before percutaneous insertion.

Pleasant and relaxing music is another means of comforting and calming a patient before and during surgery.

Modesty. Protecting a patient’s modesty is always helpful in reducing anxiety. The surgical staff must address patient concerns about being naked in the operating room.

All female patients are provided with disposable panties. To expose the surgical field fully during liposuction of the lateral hip, the side straps of these panties can be cut and taped to the patient’s back and abdomen before scrubbing the area.

Male patients are advised to wear nylon bathing pants rather than white cotton briefs, which absorb unsightly bloody drainage.

Oral Anxiolytic Drugs

By decreasing a patient’s anxiety, the clinician can decrease the need for narcotics and sedatives. The ideal anxiolytic drug produces a decreased level of anxiety in a patient without the risks of respiratory depression and decreased ventilation associated with benzodiazepine sedatives and narcotics. An anxiolytic should produce its effect without the patient feeling “sedated” or “drugged.”

Anxiolytics are not necessary for effective tumescent liposuction, but they improve the quality of the experience for both the patient and the surgical staff without increased risks of drug toxicity.

Clonidine. This alpha₂-adrenergic agonist is given orally to treat severe hypertension. Clonidine tends to lower both blood pressure and pulse rate and also provides sedation. Its sedative properties have traditionally been considered an annoying side effect that has limited its use in treating hypertension in ambulatory patients.

For liposuction surgery, however, low-dose clonidine is an excellent anxiolytic that does not impair respiratory function. At a dose of 0.1 mg, clonidine has significant anxiolytic properties without affecting respiration or the protective airway reflexes. It also attenuates intraoperative hypertension, increases the efficacy of local anesthesia, and decreases the incidence of intraoperative sinus tachycardia associated with the subcutaneous infiltration of dilute epinephrine (see Chapter 24).

Lorazepam. The combination of lorazepam and clonidine acts synergistically to achieve anxiolytic effects in most patients with minimal sedative effects and minimal respiratory depression (see Chapter 24). Low doses of lorazepam (1 mg) and clonidine (0.1 mg) have a long history of safe use by outpatients. These drugs are much safer than the medications routinely employed for IV conscious sedation.

This absence of significant risk for respiratory depression is why the use of lorazepam (1 mg) and clonidine (0.1 mg) with the tumescent technique is consistent with the definition of liposuction totally by local anesthesia.

Narcotics and Sedation

A few patients have a true phobia or clinical anxiety-hysteria complex about the prospect of a surgical procedure and require narcotic and sedative drugs.

Dermatologic surgery has a long tradition of using small doses of IM narcotics, IM midazolam, and sublingual diazepam to supplement local anesthesia for office procedures. These limited doses have not been associated with significant risks of respiratory depression.

Sodium Bicarbonate. Routine use of IM, IV, or sublingual sedatives or narcotics is not necessary for tumescent infiltration. The addition of sodium bicarbonate (NaHCO₃) to a local anesthetic solution neutralizes the pH of the solution and thus eliminates most of the stinging pain associated with infiltration. The use of sodium bicarbonate therefore has also largely eliminated the need for narcotics and sedatives.

Benzodiazepines. Some surgeons continue to employ IM narcotic analgesics and IM benzodiazepines such as midazolam because they allow more rapid tumescent infiltration.

I believe that patients feel better without these IM drugs, and the nausea associated with narcotics and the other adverse effects of benzodiazepines (e.g., antegrade amnesia) can be avoided. When IM narcotics or benzodiazepines are used routinely in conjunction with tumescent local anesthesia, the tumescent liposuction cannot be said to be done totally by local anesthesia.

Surgeon Anxiety

Anxiety about surgery can affect the surgeon as well as the patient. A surgeon may be anxious and insecure due to the lack of training in a particular technique and may communicate that anxiety to the patient, whose anxiety will also be increased. The situation especially may be encountered with the tumescent technique, since many surgeons have had no formal training in doing liposuction totally by local anesthesia.

All surgeons become anxious and worried about the possibility of a patient experiencing insufficient local anesthesia. Among surgeons whose training has inculcated the idea that local anesthesia is usually inferior to systemic anesthesia, the thought of relying entirely on local anesthesia for liposuction is especially anxiety provoking.

I suspect that some surgeons routinely give IM narcotics and sedatives during tumescent infiltration and liposuction more to allay their own anxiety than to make the patient more comfortable. Other surgeons overcome this anxiety by seeking specific training in the specialized techniques of tumescent infiltration and liposuction totally by local anesthesia.

Interpersonal Skills and Recommendations

This section offers my personal suggestions to facilitate tumescent infiltration and addresses the responsible physician, nurse, or surgeon directly.

Before beginning infiltration, make an effort to develop a personal rapport with the patient. First, introduce yourself and make good eye contact.

To divert the patient’s attention from the infiltration, engage in conversation about another subject, as follows:

1. Inquire about the patient’s background and family situation.
2. Focus on topics the patient seems to enjoy.
3. Inquire about recent or future vacations.
4. Ask about the patient’s children.
5. Use the patient’s name often in conversation.
6. Touch the patient gently.
7. Share some anecdotes about yourself.

Tell Patient What To Expect

Before beginning a procedure, tell the patient what is going to be done and what it might feel like. Educate the patient about the infiltration procedure.

Tell the patient about the discomfort and the duration of the infiltration process. Offer to give a detailed explanation for any question the patient may have about the procedure.

Address Infiltration Concerns

Encourage the patient to inform you if any significant discomfort requires infiltration of additional anesthetic solution. Ask the patient to ignore or endure any trivial or easily tolerated discomfort.

Explain the importance of good communication between the staff and the patient. Emphasize how much the staff relies on information from the patient during the procedure.

Be alert to the patient’s facial expressions (e.g., grimace, wince), body language (e.g., flinch, jump, cringe, shudder, subtle foot movement), and sounds (e.g., groan, whimper). Assess the patient’s mannerisms and degree of discomfort. Repeatedly ask if the infiltration is being done in a comfortable manner.

Optimize Patient’s Physical Comfort

Use a blanket warmer to preheat the anesthetic solution before infiltration. Warm anesthetic solution is less painful and minimizes patient shivering.⁸

Use a water bath to preheat surgical soap and normal saline used to wipe off excess soap. For comfort and modesty, place prewarmed maroon-colored terry cloth towels beneath patients. Warmed towels can also be used to cover the patient and keep the patient comfortable in a cool operating room.

If a patient states the infiltration is uncomfortable, try a slight modification of the technique, as follows:

1. Increase or decrease the rate of pumping the fluid.
2. Use a smaller needle.
3. Approach the tender area from a different direction.
4. Grip the tissues more gently or more firmly.
5. Avoid pinching the tissues with the gripping hand.
6. Inject only a small volume in the painful area, then return to the area later after anesthetic has taken effect.

Develop Methodical Routine

Develop a systematic routine for infiltration, and follow it to avoid confusion about which areas have been infiltrated.

Before infiltration, estimate the volume of solution that will be used to infiltrate each area, then calculate the expected total lidocaine dosage (mg/kg). This allows advance adjustments in the concentration of lidocaine and avoids use of too much lidocaine.

Promote Teamwork

Ask other staff members for their opinions on how to infiltrate each patient. This can minimize the discomfort of infiltration. Also, comparing tentative estimates of the volume of anesthetic solution required for each area often improves the accuracy of the final estimate. This openness promotes cooperation among the surgical team.

If it becomes apparent during the infiltration process that the final dosage of tumescent lidocaine will exceed the maximum intended amount, the concentration should be decreased, or the number of areas to be treated should be limited and postponed until subsequent surgery.

To avoid surprises, the circulating nurse responsible for monitoring the patient should periodically inform the infiltrating nurse about the volume of anesthetic solution already infiltrated.

Office and Time Efficiency. When well-trained registered nurses (RNs) do the tumescent infiltration, time is used more efficiently and safety is improved. While one RN monitors the patient and another infiltrates the local anesthesia, the surgeon can see new or follow-up patients in the clinic.

By avoiding the use of significant sedation, patients can be discharged from the office surgical facility within 30 minutes of completing surgery.

Scheduling. Because it is easier to coordinate the schedules of the surgeon and an RN than the schedules of two physicians, there is further time-saving efficiency in using an RN to do the infiltration rather than a physician-anesthesiologist. When an anesthesiologist provides systemic anesthesia, time may be wasted if one physician is delayed elsewhere, forcing the second physician to wait.

Microcannulas. The use of microcannulas allows smoother and more complete liposuction results. Thus microcannulas reduce the need for “touch-up” or “redo” procedures and extra team effort, which saves much time and expense.

Local Complications

A number of complications can occur with any type of local anesthesia. Complications may also result from insufficient anesthesia (see Box 26-1).

Necrosis of local tissue and nerve injury resulting from local anesthesia have been reported in dermatologic surgery. To my knowledge, however, no focal necrosis or nerve injury has been associated with infiltration using the tumescent technique.

Bleeding

Local subcutaneous bleeding is an unusual complication that can occur with tumescent infiltration when a sharp spinal needle punctures a blood vessel. If bleeding from a puncture site is noticed during infiltration, more fluid is infiltrated into and around the probable bleeding site to produce vasoconstriction and vascular compression. The clinician then waits a few minutes for vasoconstriction to occur, temporarily directing the infiltration elsewhere before completing it in the area of bleeding.

If a hematoma occurs, it is generally small and cannot be detected clinically until it is encountered during liposuction and causes some localized bloody aspirate. The most common anatomic locations for these tiny “infiltration hematomas” have been the midabdomen and medial knee. Such hematomas are of little clinical consequence.

Needle Break

Needle breakage can occur with any injection, although I am not aware of it occurring during tumescent infiltration. A needle break is more likely with aggressive, crude, or indelicate technique.

The needle should be withdrawn sufficiently to allow a change of needle direction by pivoting about the needle tip. Attempting to change needle direction with the needle deep within the subcutaneous fat can place excessive force on the needle, causing it to bend or snap.

Facial Nerve

Paralysis. Inadvertent motor nerve blockage may occur with local anesthesia of the face. Tumescent infiltration in and around the lateral oral commissure often causes localized paralysis persisting for several hours. The motor nerves that innervate the periorbital muscles can also be temporarily paralyzed with local anesthesia.

The terminal branches of the facial nerve that innervate orbicularis oris muscles and the muscles of facial expression are particularly susceptible to tumescent local anesthesia. Paralysis of facial muscles around the mouth is a common, harmless condition that resolves within a few hours. Patients should be warned that local anesthesia around the mouth may cause temporary difficulty in moving the lip muscles.

For the surgeon’s peace of mind, one should test for facial nerve paralysis after infiltration and before liposuction. To neglect this simple test, and then to notice a motor nerve paralysis of the face only after the liposuction surgery has been initiated, makes it difficult to distinguish the possibility of cannula-induced facial nerve apraxia.

Injury and Apraxia. Injury to the mandibular branch of the facial nerve, where the nerve exits the masseter muscle’s anterior margin at the mandible’s inferior margin, may occur as a result of trauma from a liposuction cannula.

The tumescent technique should protect patients from this injury by elevating the subcutaneous fat away from the subjacent neurovascular structures. The mandibular branch of the facial nerve is located deep to the platysma muscle. During infiltration of the lateral cheek, care should always be taken to infiltrate above the platysma muscle.

Although I have never encountered this complication, I have heard reports of other surgeons whose patients had temporary facial nerve apraxia. Liposuction injury to the mandibular branch of the facial nerve may result from the following:

1. Inaccurate tumescent infiltration involving tissue deep to the platysma muscles, thereby increasing the likelihood of liposuction in this area
2. Overaggressive liposuction of the cheek
3. Use of large cannulas with large apertures, with increased risk of collateral damage to local tissues

Microcannulas have small apertures and are less likely to cause inadvertent nerve injury.

Muscle Paralysis

Periorbital muscle paralysis is a common temporary sequela of local anesthesia for blepharoplasty. It may also occur with tumescent anesthesia for CO₂ laser resurfacing of the face. Patients should be warned of this common effect.

Femoral Nerve Block

Motor blockage of the femoral nerve can occur with local nerve block used in inguinal hernia repair or with femoral nerve block for ambulatory phlebectomy. Using tumescent local anesthesia for phlebectomy eliminates the risk of temporary motor nerve paralysis of the femoral nerve.

Vision Problems

Blindness and temporary double vision have been reported as the result of a high-pressure injection of too much local anesthetic during an infraorbital nerve block.⁹ Mild tumescent infiltration provides sufficient anesthesia for either CO₂ laser resurfacing of the eyelids or for blepharoplasty.

Blindness can result from inadvertent injection into the globe of the eye during injection of local anesthetic into an eyelid. Although not always necessary, stainless-steel eye shields may be helpful in protecting the globe in some patients.

Inadvertent corneal injury or intraocular injection can be avoided by a gentle tumescent injection that is initiated lateral to the orbital rim. As the bleb of subcutaneous anesthesia migrates medially, additional injections can be delivered immediately below the elevated dermis, with direct visualization of the needle placement far from the globe.

Syncope

Vasovagal syncope or near-syncope can occur before, during, or after any percutaneous injection. Vasovagal syncope in the setting of tumescent infiltration and liposuction can usually be prevented. Patients with any history of fainting for any reason are predisposed to a vasovagal event during any medical procedure (see Chapter 8).

This reflexogenic neurologic-cardiovascular reaction during tumescent infiltration or liposuction can be prevented by a prophylactic IV injection of atropine (0.3 to 0.4 mg), given immediately after IV access has been established.

Insertion and Injection Pain

Needle Insertion. To minimize painful injections, slow technique and a sharp 30-gauge needle are used to anesthetize the injection site. Subsequent injections at this site are virtually painless (see earlier discussion).

Injection of Anesthetic. This pain is minimized by injecting the anesthetic slowly. The pH of 4 to 5 is typical of commercially available solutions of lidocaine for local anesthesia. An acidic solution is painful on intradermal injection. Sodium bicarbonate neutralizes a local anesthetic solution to a pH of 7.0 to 7.4.^10,11 For example, a 50-ml bottle of 1% lidocaine (without epinephrine) can be neutralized with 3 mEq of sodium bicarbonate (8.4% NaHCO₃ = 1 mEq/ml).

Whether neutralized or not, lidocaine with epinephrine seems to sting more than lidocaine without epinephrine. A tumescent solution of local anesthesia (500 to 1000 mg of lidocaine, 1 mg of epinephrine, and 10 mEq of NaHCO₃ in 1 L of 0.9% NaCl) seems to produce the least stinging of all the local anesthetic solutions on intradermal injection.

References

1. Knize DM, Fishell R: Use of preoperative subcutaneous “wetting solution” and epidural block anesthesia for liposuction in the office-based surgical suite, Plast Reconstr Surg 100: 1867-1874, 1997.
2. Knize DM, Pepper G: Does the tumescent technique require tumescence? Aesthetic Surg Q 16:59, 1996.
3. Hanke CW, Coleman WP III, Lillis PJ, et al: Infusion rates and levels of premedication in tumescent liposuction, Dermatol Surg 23:1131-1134, 1997.
4. Rubin JP, Bierman C, Rosow CE, et al: The tumescent technique: the effect of high pressure and dilute epinephrine on absorption of lidocaine, Plast Reconstr Surg 103:990-996, 1999.
5. Klein JA: Tumescent technique for local anesthesia improves safety in large-volume liposuction, Plast Reconstr Surg 92: 1085-1098, 1993.
6. Pitman GH: Suction-assisted lipectomy: hips, thighs—tumescent technique. Presentation at Symposium on Aesthetic Surgery, San Francisco, March 1996.
7. Moorthy SS, Dierdorf SF, Yaw PB: Influence of volume on the spread of local anesthetic–methylene blue solution after injection for intercostal block, Anesth Analg 75:389-391, 1992.
8. Fialkor JA, McDougall EP: Warmed local anesthetic reduces pain on infiltration, Ann Plast Surg 36:11-13, 1996.
9. Laskin DM: Diagnosis and treatment of complications associated with local anesthesia, Int Dent J 34:232-237, 1984.
10. Stewart JH, Cole GW, Klein JA: Neutralized lidocaine with epinephrine for local anesthesia, J Dermatol Surg Oncol 15: 1081-1083, 1989.
11. Stewart JH, Chen SE, Cole GW, Klein JA: Neutralized lidocaine with epinephrine for local anesthesia. II, J Dermatol Surg Oncol 16:842-845, 1990.

Figure 26-1 Tumescence and detumescence. A, Cross section of subcutaneous fat before initiating tumescent infiltration. B, Tumescent liposuction is facilitated by directing initial infiltration along deepest plane of subcutaneous fat. If infiltration is initiated too superficially, it becomes difficult to palpate and recognize deeper interface between fat and muscle fascia. Thus subsequent attempts to infiltrate deepest layers of fat are more challenging. C, After blocking nerves in deeper layer of fat, subsequent infiltration of more superficial tissue can be accomplished with less discomfort. After infiltrating all fat within a targeted compartment, infiltrating an additional small volume of tumescent fluid into most superficial fat will produce peau d’orange skin. D, Partial detumescence of infiltrated fat compartment occurs as tumescent fluid flows through interstitial gel substance into surrounding adipose tissue. Allowing sufficient time (20 to 30 minutes) for detumescence to occur before doing liposuction permits maximal vasoconstriction and local anesthesia. With detumescence, it becomes easier to grip subcutaneous tissue and thus easier to do liposuction.

Figure 26-2 Fanlike pattern of tumescent infiltration using spinal needle. Concentric topographic ellipsoid rings accurately indicate relative location and depth of subcutaneous fat. Horizontal and vertical straight lines provide a grid that helps to achieve uniform infiltration. Intersecting lines indicate sites of intradermal injections of local anesthesia through which spinal needle is inserted for tumescent infiltration.

Figure 26-3 Tumescent infiltration initially produces loculations, or small deposits of anesthetic solution, within adipose tissue. As spinal needle is advanced into subcutaneous fat, it punctures adipocytes and perforates fibrous septa while simultaneously injecting anesthetic solution. Subsequently, after spreading by bulk flow through interstitial gel substance, tumescent fluid becomes more homogeneously distributed. Intensity of anesthesia and vasoconstriction increases as greater numbers and lengths of nerves and blood vessels are exposed to tumescent anesthesia.

BOX 26-1 Reasons for Insufficient Local Anesthesia

Anesthetic Technique

Lack of attention to detail

Insufficient local infiltration into fibrous areas

Incomplete volume of tumescent anesthetic solution

Insufficient concentration of local anesthetic drug

No sodium bicarbonate in tumescent anesthetic solution

Gripping tissue with excessive force

Surgical Technique

Unnecessarily large diameter of cannulas

Overaggressive approach

Patient Factors

Anxiety

Previous liposuction

Residual scarring

Fibrosis

 

TABLE 26-1 Tumescent Infiltration: Estimated Time (Minutes) and Volume (Milliliters)*
Anatomic Area	Small Patient (min/ml)	Large Patient (min/ml)
Outer thighs	15/600	25/1400
Inferolateral buttocks	4/200	6/400
Inner thighs	15/800	25/1600
Inner knees	5/200	10/400
Hips	15/600	25/1200
Waist	10/300	20/600
Flanks/postaxilla	15/400	25/800
Buttocks	15/400	20/900
Abdomen	30/1400	60/2800
Arms	20/500	30/1000
Male breasts	15/400	30/1000
Male flanks	15/600	25/1000
*Time and volume vary according to patient tolerance. For bilateral symmetric areas, use double the indicated time per side. Physician may prefer to infiltrate chin, cheeks, jowls, and breasts, which require special techniques (see Chapters 35, 37, and 38).