Safe limits for aspirate volume under wet liposuction

Hypovolemia is a hemodynamic disorder occasionally associated with liposuction. The purpose of this study is to settle a safe limit for the volume of aspirate under wet liposuction relating this volume to body weight. The criteria used to establish this limit were based on the Advanced Trauma Life Support (ATLS).

Thirty patients underwent wet liposuction and were submitted postoperatively to a 24-h noninvasive monitoring control of vital signs. Tachycardia (over 100 bpm) and systolic hypotension (below 100 mmHg) were recorded as well as urinary volume and respiratory rate. Hemoglobin, hematocrit, and leukocyte counts were determined preoperatively and also determined 1 and 6 h postoperatively.

The volume of aspirate ranged from 1,480 to 3,980 ml (2.6% to 6.9% of body weight). Hemoglobin count decreased around 6 h postoperatively compared to the immediate preoperative period (p<0.0001). An increase of leukocytes was observed around 6 h postoperatively when compared with the preoperative period-nearly 30 min before surgery (p<0.0001). No association was found between hemoglobin or leukocyte counts and volume of aspirate. In 15 patients, tachycardia and/or hypotension were recorded postoperatively. These hemodynamic disorders were associated to volumes of aspirate higher than 5% of body weight.

Under wet liposuction, a volume of aspiration not superior to 5% of body weight is proposed as a safe limit. It has been found as a clue to avoid hypovolemia and subsequently the shock. This statement is in agreement with ATLS guidelines.