Liposuction Key Points Quiz

Liposuction Key Points

• Many liposuction patients have pre-existing obesity or massive weight loss conditions. Obesity is classified by BMI (Body Mass Index), calculated as weight (kg) divided by height (m²).
• A BMI over 25 kg/m² indicates overweight, over 30 kg/m² is obese, and over 40 kg/m² is severely obese. Obesity affects 50% of the US population.
• Liposuction fluid can be absorbed systemically, potentially leading to fluid overload, lidocaine poisoning, or epinephrine toxicity. The wetting solution used in liposuction may or may not contain lidocaine with epinephrine.
• Blood loss during liposuction is determined by the technique and amount of fat removed. Total blood loss is calculated by multiplying the percentage of blood in the aspirate by the total amount suctioned. Blood loss in the tumescent technique is approximately 1% of the aspirate.
• Following fluid guidelines and monitoring urine output helps prevent low or high blood volume. Current fluid management guidelines are not definitive. Fluid management factors include monitoring IV fluids, wetting solution, aspirate, estimated blood loss, and urinary output.
• Aspirate is the combined volume of fat and fluid removed. Approximately 60-70% of the wetting solution remains for hypodermoclysis.
• Potential perioperative complications include infections, fat or pulmonary embolisms, lidocaine toxicity, punctures, fluid imbalance, hypothermia, intestinal perforation, and organ perforation.
• Suction-assisted lipoplasty is the most common elective cosmetic procedure in the US.
• Liposuction removes subcutaneous adipose tissue using a cannula and suction. Various techniques exist (see Table 44.1).
• Laser-assisted liposuction may be used in conjunction with wetting solutions to remove larger volumes of fat.
• Massive weight loss (MWL) secondary to bariatric surgery has increased the demand for body contouring procedures in the US.
• Liposuction techniques differ significantly.

Liposuction Techniques

• Dry Technique:
  • No subcutaneous fluid is injected before suctioning.
  • Disadvantages include swelling and discoloration.
  • Blood loss is 20% to 45% of the aspirate.
  • Transfusions are often necessary for large removals.
  • Avoid aspirate volumes over 1000 mL to reduce heavy blood loss risk.
  • Cannot be used with ultrasound-assisted liposuction due to thermal injury risk.
• Wet Technique:
  • Infiltration of 200 to 300 mL of wetting solution is applied pre-suction.
  • Solution may contain additives like lidocaine, epinephrine, or bicarbonate.
  • Epinephrine decreases blood loss to 4% to 30% of the aspirate.
• Tumescent Technique:
  • Uses large volumes of dilute lidocaine (>4 L) for infiltration, along with other components for the tumescent fluid.
  • Blood loss is approximately 1% of the aspirate.

Anesthetic Considerations

• Preoperative Medications: Discuss patient's preoperative medications and potential anesthetic concerns. Beta-blockers may cause bradycardia, claudication, and sedation. Monoamine oxidase inhibitors (MAOIs) increase norepinephrine, affecting the central and sympathetic nervous systems, potentially causing hypertension and sedation. Tricyclic antidepressants may cause seizure-like activity. Their anticholinergic effects increase the risk of central anticholinergic syndrome with atropine or scopolamine. Oral contraceptives and hormone replacement therapy increase the risk for deep vein thrombosis. Venous thrombosis and pulmonary embolus have been linked to third-generation progestin use with low estrogen levels.

Obesity and Related Conditions

• Patients with BMI >30 are at increased risk for perioperative complications due to coexisting conditions like diabetes, hypertension, and coronary artery disease.
• Obesity increases myocardial workload, leading to hypertension and ventricular hypertrophy.
• Obstructive sleep apnea (OSA) is common in obese patients. OSA coupled with deep sedation increases respiratory risk. Chronic hypoxia can cause pulmonary hypertension and cor pulmonale.
• Gastrointestinal concerns: Obesity predisposes patients to aspiration pneumonitis due to hiatal hernia, gastroesophageal reflux, decreased gastric emptying, and increased gastric acidity.
• Fatty liver infiltrates (potential cirrhosis) decrease medication metabolism, increasing local anesthetic toxicity risk.
• Weight loss methods (diets, exercise) can cause hypoalbuminemia, electrolyte imbalances, or fluid/electrolyte deficiencies.
• Sedation is often used during liposuction procedures to improve patient tolerance of punctures and discomfort. However, opioids and sedatives increase the risk of postoperative apnea.
• Patients with more than 4 L of aspirate removed should receive additional maintenance fluid (0.25 mL IV fluid per mL of aspirate over 4 L).

Fluid Resuscitation

• No definitive guidelines exist for fluid management during liposuction.
• Factors include monitoring IV fluids, wetting solution, aspirate amount, estimated blood loss, and urinary output.
• Aspirate refers to the total fat and fluid volume removed.
• Approximately 60-70% of the wetting solution remains for hypodermoclysis.
• Fluid administration should be guided by patient vital signs and urinary output.

Postoperative Complications

• Embolism:
  • Pulmonary embolism (PE) is the leading cause of death in liposuction with 4.6 per 100,000 patients. PE stems from fat or venous thrombosis. Symptoms include shortness of breath, chest pain, cough, coughing up blood, palpitations, wheezing, and angina.
  • Deep vein thrombosis (DVT) commonly presents with leg pain, the Hohmann sign, swelling, redness, tachycardia, and warmth in affected extremity. Risk factors include thrombophlebitis, smoking, obesity, prior DVT, and hormone use (HRT/oral contraceptives). Prophylactic intermittent pneumatic leg compression is recommended to prevent PE.
  • Treatment options for PE/DVT include heparin, thrombolytics, low-molecular-weight heparin, and hemodynamic support.
• Pulmonary Edema:
  • Results from excessive IV fluid administration causing hypotension, or rapid absorption of wetting solution (hypodermoclysis).
• Intestinal or Organ Perforation:
  • Rare but potential complication, particularly with existing abdominal scars. Susceptible areas include abdomen, thorax, retroperitoneum, major vessels, and kidneys. Manifestations may not become apparent for days leading to acute abdomen or sepsis necessitating emergency laparotomy.
• Hypothermia: Body temperature below normal levels.

Case Study Example

• Procedure time: 130 minutes.
• Wetting solution: 4300 mL.
• Aspirate: 3800 mL.
• Fluid resuscitation (crystalloid): 3400 mL.
• Urinary output: 625 mL.
• Post-op vitals: Blood pressure 167/92, heart rate 119 bpm, respiratory rate 26 breaths per minute, temperature 35.1°C.

Test your knowledge on the key concepts of liposuction, including patient conditions, complications, and fluid management. This quiz covers critical points that every practitioner should understand to ensure patient safety and effective procedures.