Effects of Epidural Needle Rotation on Evolution of Unilateral Epidural Block and Patients' Hemodynamics beside Recovery Profile in Patients Undergoing Arthroscopic Knee Surgeries; A Randomized Clinical Trial.

Objective: To evaluate the evolution pattern of epidural block after rotating the needle tip 45° to the operative side and evaluate its effects on patients' hemodynamics and recovery profile in those undergoing arthroscopic knee surgery.

Methods: Forty participants were randomly subdivided into control and rotation group (n=20). An 18-gauge, 3.5 inch, Tuohy needle was placed at the level of L4-5 and pushed forward into the epidural space through parasagittal approach, in control group, the needle was pushed forward to the epidural space in cephaldad 90 degrees. For the rotation group, the needle was pushed forward to the epidural space and the tip was rotated 45 degrees to the surgical side.15 mL of bupivacaine 0.5% was injected and evolution of sensory and motor blocks until 2-segment regression of the sensory level below to T10 as well as total duration of motor block and surgery were recorded. Hemodynamic parameters (HR, MAP, and SPO2), hypotension, fluid intake, vasopressors, first ambulation and spontaneous urination were recorded. Statistical analysis was performed using SPSS and P≤0.5 considered significant.

Results: ensory block up to T10 level, Complete motor block and time for 2-segment regression of sensory level were earlier in the 45°-rotation than in the control group (<0.001). Total duration of motor block in control group was lower than rotation group (<0.001).Hypotension, N&V, vasopressors and fluid intake showed no statistically difference between the two groups (=0.219). First spontaneous urination and ambulation were significantly lower in rotation group (<0.001).

Conclusion: 45 degrees' needle rotation to the surgical side provides a faster block evolution and hastened recovery profile with no significant difference in hemodynamic fluctuations.

Clinical Trial Registry: IRCT20130518013364N7.