Deep vein thrombosis and pulmonary embolism

This is one of the main causes of death in association with cosmetic surgery, although most patients who undergo lipoplasty have low to moderate risk for developing deep vein thrombosis, with proper patient selection and DVT prophylaxis.

Therefore, a mandatory preoperative evaluation to identify factors of risk for thrombosis, as well as the use of elastic stockings, pneumatic systems of intermittent compression, adequate hydration and early mobilization are usually sufficient to prevent venous thrombosis in healthy patients undergoing lipoplasty.

In our procedure, we carry out early mobilization (6–8 hours after the surgery); we always use compressive garments, as well as lymphatic drainage and massage of the lower limbs of the patient one day after the surgery. This work is carried out by physiotherapists on all our patients, and has decreased our rate of thrombosis of the deep veins.

Hypothermia

Mild hypothermia (33 to 36°C) is common in liposuction patients and is the result of a combination of anesthesia-induced impairment, thermoregulation, exposure to a cold environment, and the infiltration of cold solutions. General anesthesia results in vasodilation, an increase in cutaneous heat loss, decreased heat production, and a redistribution of body heat from the core to the periphery. Even mild hypothermia may alter coagulation factors, increase bleeding, increase the incidence of surgical wound infection, prolong recovery time and can lead to increased risk of coagulopathy.

Some preventive measures can be taken to reduce the effects of hypothermia. The patient should be kept in a warm environment preoperatively to minimize the initial temperature drop during induction of anesthesia. Hot air blankets are the most effective noninvasive warming technique available today. Simply covering the patient’s upper extremities and head with a forced air device will help maintain a normal core body temperature and avoid metabolic and blood composition changes. Warming of the intravenous fluids, increased room temperature, and the use of warmed infiltration fluids are some steps that can be performed to prevent hypothermia.

Lidocaine and adrenaline toxicity

The FDA defines 7 mg/kg as the maximum safe dose of lidocaine with epinephrine (and 5 mg/kg for lidocaine only) for regional anesthesia. Literature on liposuction reports the use of lidocaine in doses of up to 33–35 mg/kg,¹ but always in solutions with adrenaline and with low concentration of lidocaine (0.1%) in large volume infiltration. Since the subcutaneous area is able to retain lidocaine, it is be restricted to the infiltration site, and only the exceeding molecules (1 mg of lidocaine for 1 g of tissue) would be available to be submitted to conventional pharmacokinetics. Hepatic function is an important factor that interferes in the concentration of lidocaine. Even drugs which interact with lidocaine in the hepatic cytochromes, such as antidepressants, might raise the serum concentration of lidocaine, causing signs of toxicity in the central nervous and cardiac systems. The hepatic metabolization of lidocaine and adrenaline reaches its serum peak within three hours after infiltration, returning to normal values after 12 hours.⁶

The excessive infiltration of solutions with lidocaine can cause toxicity, cardiotoxicity, convulsions, drug interaction and overdose.