Ropivacaine and levobupivacaine in combined femoral and lateral femoral cutaneous nerve block for post-operative analgesia
It is reported that the donor site pain is severe and prolonged compared to grafted site in split skin grafting. The regional nerve blocks efficaciously render primary anesthesia and prolonged post-operative analgesia. A combined femoral nerve (FN) and lateral femoral cutaneous nerve (LFCN) regional block can anaesthetize the broad anterolateral thigh surface for graft harvesting for lower-limb skin grafts. Levobupivacaine and ropivacaine, the recent pure single S- (-)-enantiomers of bupivacaine-manifest ameliorated cardiovascular and central nervous system safety profiles.
Poor general condition and underlying protein energy malnutrition make the patients with burns unsuitable candidates for general or spinal anesthesia, which can hinder in their requirement of multiple surgeries.
A study has been done that mentioned the role of magnesium sulphate as an adjuvant with levobupivacaine and ropivacaine required in combined femoral and lateral femoral cutaneous nerve (LFCN) blocks in burns of relative sparing of thigh part.
The study included, 54 adult patients (18-65 years), undergoing split-thickness skin graft harvest from the thigh, assigned to three equal groups of 18 each. Group L patients obtained femoral nerve (FN) block with 15 mL of 0.5% levobupivacaine and 8 mL for LFCN block; Group LM patients obtained 14 mL of 0.5% levobupivacaine along with 1.0 mL of 15% magnesium sulphate for FN block, 7.5 mL of 0.5% levobupivacaine with 0.5 mL of 15% of magnesium sulphate to LFCN block and Group R patients obtained 15 mL of 0.5% ropivacaine for FN block and 8 mL of 0.5% ropivacaine for LFCN block. In first 24 hours post-operatively; time to block onset and complete surgical block, duration of analgesia, total analgesic dose and the overall analgesia satisfaction score were determined. Quantitative data were assessed with ANOVA and qualitative data subjected to Chi-square tests. Intergroup comparison was executed with independent t-test.
Duration of post-operative analgesia did not have any change with the addition of magnesium (P = 0.610). Time to onset of the block notably decreased with the addition of magnesium (P = 0.0341), but time to complete surgical block onset was similar across the groups. It was culminated that both ropivacaine and levobupivacaine have good perioperative analgesic efficacy. Magnesium, as an analgesia adjuvant with levobupivacaine does not extend the duration of post-operative analgesia.