The paramedian technique: a superior initial approach to continuous spinal anesthesia in the elderly

Spinal anesthesia in elderly patients is frequently associated with significant technical difficulties. Thus, we compared the classical midline approach to the paramedian approach to perform continuous spinal anesthesia (CSA).

We prospectively studied 40 patients aged >75 yr who underwent open surgical repair of a hip fracture. These patients were randomly allocated to one of two groups: Group M: midline approach, and Group PM: paramedian approach. Patients were positioned in the lateral decubitus to receive CSA at L4-5 level. CSA was considered successful if cerebrospinal fluid was obtained through the needle. In case of initial failure in either approach, the same approach was repeated by the same operator. If two attempts were unsuccessful, the other anatomical approach was used by the same operator. If both approaches failed, a staff anesthesiologist performed a final attempt. In case of failure or insufficient block, the patient received general anesthesia.

The success rate after the first attempt was 85% (17) for Group PM and 45% (9) for Group M (P = 0.02). All catheters were successfully introduced. No patient required general anesthesia. Vascular puncture after needle puncture was observed in six patients in Group M versus 0 in Group PM (P = 0.03), but none were of clinical consequence. No other clinically significant complications were observed.

In summary, after the initial attempt, the paramedian approach is associated with an increased success rate, compared with the midline approach, during the performance of CSA in elderly patients.