BACKGROUND: As a reaction to reported adverse outcomes after lidocaine infiltration in tumescent liposuction, prilocaine has gained increasing popularity. Previous studies investigating large-volume liposuction procedures found maximum prilocaine levels and methemoglobinemia up to 12 h postoperatively, suggesting that liposuction should be performed as a hospital procedure only. The aim of this study was to determine prilocaine plasma levels and methemoglobinemia in patients after low- to average-volume liposuction for the purpose of defining the required postoperative surveillance period. METHODS: In 25 patients undergoing liposuction involving less than 2,000 ml prilocaine levels and methemoglobinemia were measured over 4 h postoperatively. Liposuction was conducted after the tumescent technique using a 0.05% hypotonic prilocaine solution with epinephrine. RESULTS: The average prilocaine dose was 6.8 + 0.8 mg/kg, with a maximum dose of 15 mg/kg. The peak prilocaine plasma level of 0.34 mug/ml occurred 3 h after the infiltration. The mean methemoglobinemia at this time point was 0.65%. Only one patient demonstrated a slightly elevated methemoglobin level of 1.4%, but lacked any clinical signs of methemoglobinemia. The prilocaine recovery in the aspirate averaged 36 +/- 4%, indicating that a large amount is removed by suctioning. CONCLUSIONS: The patients did not experience high plasma levels of prilocaine or methemoglobinemia undergoing liposuction involving less than 2,000 ml using a 0.05% hypotonic prilocaine solution. The authors therefore conclude that this procedure can be performed safely with a monitoring period of 12 h.
BACKGROUND: As a reaction to reported adverse outcomes after lidocaine infiltration in tumescent liposuction, prilocaine has gained increasing popularity. Previous studies investigating large-volume liposuction procedures found maximum prilocaine levels and methemoglobinemia up to 12 h postoperatively, suggesting that liposuction should be performed as a hospital procedure only. The aim of this study was to determine prilocaine plasma levels and methemoglobinemia in patients after low- to average-volume liposuction for the purpose of defining the required postoperative surveillance period. METHODS: In 25 patients undergoing liposuction involving less than 2,000 ml prilocaine levels and methemoglobinemia were measured over 4 h postoperatively. Liposuction was conducted after the tumescent technique using a 0.05% hypotonicprilocaine solution with epinephrine. RESULTS: The average prilocaine dose was 6.8 + 0.8 mg/kg, with a maximum dose of 15 mg/kg. The peak prilocaine plasma level of 0.34 mug/ml occurred 3 h after the infiltration. The mean methemoglobinemia at this time point was 0.65%. Only one patient demonstrated a slightly elevated methemoglobin level of 1.4%, but lacked any clinical signs of methemoglobinemia. The prilocaine recovery in the aspirate averaged 36 +/- 4%, indicating that a large amount is removed by suctioning. CONCLUSIONS: The patients did not experience high plasma levels of prilocaine or methemoglobinemia undergoing liposuction involving less than 2,000 ml using a 0.05% hypotonicprilocaine solution. The authors therefore conclude that this procedure can be performed safely with a monitoring period of 12 h.