ABSTRACT
BACKGROUND: Ischemia-reperfusion injury in free flaps is associated with tissue damage and is one of the main factors causing flap failure in reconstructive microsurgery. The aim of this study is to assess whether any ischemia-reperfusion injury takes place during a microsurgical flap reconstruction as seen through the levels of malondialdehyde (MDA) and superoxide dismutase, biomarkers of oxidative stress, and to analyze the effect of lidocaine in this process. METHODS: Twenty-four patients operated for immediate breast reconstruction using the Deep Inferior Epigastric Perforator free flap technique were divided into two groups: one group was treated with a lidocaine intravenous perfusion and the other group with a saline perfusion. MDA and superoxide dismutase (SOD) levels were measured at several points before, during, and after surgery. RESULTS: There was an increase in MDA levels in both groups, but the lidocaine group experienced a decrease during reperfusion. On the other hand, we observed a rise in SOD levels in both groups, but a decrease during reperfusion in the placebo group. However, these differences between groups were not statistically significant. CONCLUSIONS: The decreased SOD activity and increased MDA content in our research prove a redox imbalance and high reactive oxygen species levels in flaps, indicating that tissues experience ischemia-reperfusion injury during microsurgical reconstruction. Lidocaine may have a protective effect in free flap surgery, but our results were not statistically significant, so further studies will be required.
Subject(s)
Anesthetics, Local/administration & dosage , Epigastric Arteries/transplantation , Lidocaine/administration & dosage , Mammaplasty/methods , Perforator Flap/blood supply , Reperfusion Injury/prevention & control , Adult , Biomarkers/blood , Breast Neoplasms/surgery , Double-Blind Method , Female , Humans , Infusions, Intravenous , Malondialdehyde/blood , Microsurgery , Middle Aged , Oxidative Stress , Prospective Studies , Superoxide Dismutase/bloodABSTRACT
Gas chromatography was used in combination with flame ionization detection (GC-FID) to develop a method for determining cocaine and its two metabolites, benzoylecgonine (BEG) and ecgonine methyl ester (EME), in bile and vitreous humor. The method used a 12 m x 0.2 mm i.d. column of 0.33 microm film thickness packed with 5% phenylmethylsiloxane, and proadifen as a reference compound. Drug-free bile and vitreous humor samples were used to prepare solutions of the target compounds at concentrations over the range 0.1-4 microg ml(-1) that were subjected to solid-phase extraction through Bond Elut Certify columns and derivatized with 99:1 (v/v) N,O-bis-trimethylsilyltrifluoroacetamide (BSTFA)/trimethylchlorosilane (TMCS). Calibration graphs were highly linear, with correlation coefficients above 0.99 in all instances. Also, the precision of the method was found to be quite acceptable, with coefficients of variation less than 5% for bile and less than 7% for vitreous humor. The average extraction yields ranged from 73.6% to 91.2% for bile and from 71.5% to 92.2% for vitreous humor. The proposed method was used to analyse 26 samples of bile and as many of vitreous humor from individuals fatally poisoned by cocaine, whether alone or in combination with other drugs. The mean drug levels found were 0.75 and 1.54 microg ml(-1) for cocaine in bile and vitreous humor, respectively, 6.35 and 0.94 microg ml(-1) for BEG, and 2.18 and 0.61 microg ml(-1) for EME.
