A Study On The Safety Of Extensive Liposuction From The Perspective Of Local Anesthetic Toxicity And Fluid Management

Objective1 To systematically evaluate the safety and efficacy of lidocaine in liposuction,and to study the pharmacokinetics of lidocaine in extensive tumescent liposuction with segmental infiltration of lower concentration lidocaine under monitored anesthesia.2 To systematically evaluate the safety and efficacy of fluid management in liposuction,and to study the effect of modified fluid management in extensive tumescent liposuction with segmental infiltration.Methods1 A meta-analysis performed using PubMed and other databases identifies all published studies evaluating lidocaine in liposuction.After the quality evaluation and data extraction of the included literature,the software is used for Meta analysis such as R.2 The consecutive patients’ serum levels of lidocaine and MEGX are taken every 4 hours during the first 24 hours after the second infiltration,and pharmaceutical parameters are studied.3 A meta-analysis performed using PubMed and other databases identifies all published studies evaluating fluid management in extensive liposuction.After the quality evaluation and data extraction of the included literature,the software is used for Meta analysis such as R.4 The effects of temperature and indwelling time of tumescent fluid on blood loss in liposcution are evaluated by single blind randomized controlled trial;urine volume,lactic acid value and vital signs of the patients undergoing extensive liposuction with segmental infiltration are recorded to evaluate the risk of volume overload under the modified fluid management strategy.Results1 Results of Bayesian Meta-Analysis:the peak concentration of lidocaine and its metabolites are within the safe range(<3 μg/ml),and the 95%confidence interval(95%CI)of lidocaine peak time is 8.51-10.68 hours.In addition,the classical meta-analysis results showes that the difference of Visual Analogue Scores under monitored anesthesia care(-0.19)was smaller than that in the local anesthesia group(2.12).2 In extensive liposuction with segmental infiltration,the peak lidocaine level 1.71 ±0.49 μg/mL occurs after 15.1±5.58 hours;the peak MEGX level 0.64±0.16 μg/mL is observed after 23.6± 19.5h.The peak concentration of lidocaine plus MEGX(2.68±1.16μg/mL)is observed after 16 h.The extensive liposuction covering the 30%total body surface areas is well tolerated by the patients under tumescent anesthesia with segmental infiltration.3 Results of classic Meta-Analysis:the difference of hemoglobin level between preand post-operation with wet liposuction(4.03g/l)is greater than that with super-wet liposuction(1.08g/l).The results of Bayesian meta-analysis of other indicators of fluid management:blood sodium and potassium decreased(not significant);mean arterial pressure decreased(not significant),heart rate increased(not significant);the minimum value of 95%CI of perioperative urine volume is over 1ml/kg/h,indicating adequate circulation volume and mild overload.4 The blood loss in liposuction with 0.5 hour retention and no retention of tumescent fluid are(19.89±7.52)ml and(26.25± 12.07)ml,respectively;the blood loss in liposuction with heated(37℃)and non-heated tumescent fluid(23℃)are(30.3±6.89)ml and(29.4±5.23)ml,respectively.There are no episodes of pulmonary edema,congestive heart failure exacerbation,or other major complications.The average urine output in the operating room,the recovery room,and on the floor are 1.35,2.31,and 1.41 mL/kg/hour respectively,and blood lactic acid values are within the normal range.Conclusion:1 Systematic review results indicate that the application of lidocaine in tumescent anesthesia has a great margin of safety even if it exceeds the recommended dosage in Pharmacopoeia;monitored anesthesia care could relieve patients’ anxiety and pain during operation.2 Lidocaine and MEGX toxicity in extensive liposuction with segmental infiltration are low without adverse cardiopulmonary sequelae.The reduction of the estimated drug absorption and adequate analgesic effect of lidocaine could be attributed to the segmental infiltration in spite of the increased peak concentration and the delayed peak time of lidocaine.The deceleration of lidocaine clearance indicates that potential risk of extensive liposuction should not be neglected.3 Systematic review results indicate that the larger infiltrate-to-total aspirate ratio(IAR),the less the amount of blood loss;the urine volume analysis showed overload indicate the replacement fluid should be reduced,and attention should be paid to the homeostasis additionally.4 A half hour retention of tumescent fluid in subcutaneous tissue after injection could reduce the surgical blood loss and the blood loss amount dose not increase in the usage of a pre-heated tumescent fluid(37 ℃).In extensive liposuction with segmental infiltration,the urine volume of patients in the operating room,recovery room and ward are similar to the results of Meta analysis,but the speed of intravenous infusion are significantly decreased while the blood lactic acid value are within the normal range.Our modified fluid management strategy in extensive liposuction reflects minimal risk of volume overload with segmental infiltration.