Unilateral Epidural Blockade for Lower Limb Fracture Surgery: Parasagittal Epidural Versus Midline Epidural Anesthesia

OBJECTIVE: To compare the efficacy of parasagittal interlaminar (PIL) and midline interlaminar (MIL) approaches for epidural block in patients with lower limb orthopedic surgery. METHODS: This double-blind randomized clinical trial was performed on 40 patients undergoing tibial shaft fracture surgery. In PIL group, an 18-gauge, 3.5 inch, Tuohy needle was placed at the level of L2-3 or L3-4 intervertebral spaces and pushed forward in a posteroanterior (PA) direction vertical to the body surface. After determining the most lateral place for needle arrival in an anteroposterior (AP) view, needle was pushed forward into the epidural space. For the MIL group, needle was pushed forward from the midline interspinous space with the same method. After confirmation of needle position, 1 mL of contrast was injected to confirm the epidural space distribution and then 15 ml lidocaine 2% was injected. The sensory and motor block level, onset, duration, heart rate (HR), mean arterial pressure (MAP), and arterial oxygen saturation (SPO2), and success rate were recorded. RESULTS: Mean patients’ baseline characteristics showed no statistically significant difference between the two groups.p>0.05). Outcome measures were statistically different and significantly higher in PIL group (p-values for sensory block level <0.001, motor block level <0.001, duration of sensory block: <0.001 and duration of motor block <0.001 and success rate: <0.001). Hemodynamic variables didn’t show statistically significant difference between the two groups (p-values for Systolic pressure: 0.997, diastolic pressure:0.579, MAP:0.585, HR:0.710). CONCLUSION: Epidural anesthesia with parasagittal interlaminar approach provide deep motor block, high sensory level block, and hemodynamic stability. CLINICAL TRIAL REGISTRY: IRCT2017041615515N2