Liposuction is defined as the removal of subcutaneous fat deposits using a cannula connected to a powerful suction source. Of the different surgical techniques to achieve liposuction, the most common method is tumescent liposuction. First developed in 1987, this technique enabled liposuction to be performed on an outpatient basis because general anesthesia did not have to be administered. Tumescent liposuction involves the infiltration of a large volume of dilute local anesthetic solution into the subcutaneous adipose tissue. The goal is to expand the target tissue until it is swollen, firm, and tumescent. The firmness of the adipose tissue results in more controlled removal, easier suctioning, and less blood loss.
The primary advantage of tumescent liposuction is the ability to perform the procedure under local anesthesia. “Small volume” liposuction (less than 4 L of solution aspirated) is typically amenable to local anesthesia with monitored anesthesia care. Tumescent anesthesia promotes a significant reduction in blood loss. It also provides postoperative analgesia, which decreases the need for intravenous opioids. Although there is a reduction in hospitalization costs, “large volume” tumescent liposuction still requires general anesthesia.
There are several disadvantages to the tumescent technique. The infusion of the local anesthetic solution requires a significant amount of time. Because the cannulas are smaller, a longer period of time is needed to remove the adipose tissue. Since any blood is mixed in with the aspirated fat, the assessment of total estimated blood loss can be challenging.
The typical tumescent solution is 0.05%–0.1% lidocaine with 1:1 000 000 epinephrine in 1 L of an isotonic crystalloid such as normal saline (NS). By promoting capillary vasoconstriction, epinephrine decreases the rate of systemic lidocaine absorption and the potential for bleeding. Epinephrine should be avoided in patients with uncontrolled hypertension, coronary artery disease, pheochromocytoma, hyperthyroidism, or dysrhythmias. The acidic lidocaine solution may cause a burning sensation, so some institutions substitute lactated Ringer’s solution for NS or add sodium bicarbonate to the solution. Adding bicarbonate increase the solution pH, which decreases the burning sensation and increases the proportion of nonionized lidocaine molecules, leading to a more rapid onset. Some institutions also add corticosteroids to the tumescent solution to decrease postoperative inflammation.
The systemic absorption of lidocaine through tumescent anesthesia is quite slow. Because of the poor vascularity of adipose tissue, lidocaine plasma concentrations reach peak about 16 hours after infusion. As a result, the maximum recommended safe dose of lidocaine is quite high: 35–55 mg/kg. This dose results in peak plasma lidocaine levels well below the threshold for toxicity (5 μg/mL). The dose should be calculated based on total body weight. It is important to note that the tumescent dose is approximately five to eight times the recommended regional anesthetic dose (7 mg/kg with epinephrine).
Intraoperative fluid management can be complicated during tumescent liposuction. It must take into account for fasting deficits, maintenance requirements, intraoperative loss of ...