Can Isobaric Bupivacaine be used in Unilateral Spinal anesthesia?

Abstract

Background and aims: Unilateral spinal anesthesia is advantageous over conventional spinal anesthesia in patients receiving one limb orthopedic surgery, these advantages includes: decreased hypotension, increased patient satisfaction and faster anesthesia recovery. Unilateral spinal anesthesia can be achieved by used a hyperbaric or hypobaric local anesthetics, because the isobaric Bupivacaine is slightly hypobaric, we injected it to study the possibility to use it in unilateral spinal anesthesia, and to study its effects and sideffects in comparison with the conventional spinal anesthesia applied in our hospitals.

Materials and Methods: 40 patients were randomized into two groups:

Group U: Unilateral spinal anesthesia with 1.5 ml Isobaric Bupivacaine 0.5% in lateral decubitus with the limb to be operated facing upwards.

Group C: Conventional spinal anesthesia with 2.5-3 ml Isobaric Bupivacaine0.5%

Level of motor and sensory block, arterial pressure, pulse, need for intravenous solution or vasopressors, complications and patient's satisfaction were evaluated and compared between the groups in many times of surgery.

Results: Primary goals showed efficacy of unilateral spinal anesthesia with Isobaric Bupivacaine: Sensory block on operated side were significantly lower than on contralateral side (T12 – L3  vs  T8 – L1). motor block in the operated limb were total and were higher in all times of surgery and at the end of surgery unilateral block was present in seven patients (36.8%).

Secondary goals demonstrated superiority of unilateral spinal over conventional spinal anesthesia: MAP was significantly lower in group C and that required more fluids and vasopressors. Patient's satisfaction was higher in group U: 94.7% vs 78.9% in group C 

Conclusion: Isobaric bupivacaine in the lateral position provides predominant unilateral block in 68.4% of patients after 20 minutes and 36.8% after 60 min, and its effective and successful, it provides stability hemodynamic and requires less fluids and vasopressors, it has the satisfaction and good evaluation of patients, which makes it a better choice as a new alternative to conventional spinal anesthesia. It is also advisable to adopt it in high-risk patients to avoid hemodynamic changes during anesthesia.