Einseitige Spinalanästhesie

Abstract

Unilateral spinal anesthesia is a cost-effective and rapidly performed anesthetic technique. An exclusively unilateral block only affects the sensory, motor and sympathetic functions on one side of the body and offers the advantages of a spinal block without the typical adverse side effects seen with a bilateral block. The lack of hypotension, in particular, makes unilateral spinal anesthesia suitable for patients with cardiovascular risk factors e. g. aortic valve stenosis or coronary artery disease. Increasing numbers of surgical procedures are now being performed on an outpatient basis. Until now, spinal anesthesia has been considered unsuitable for this, not only because of the high incidence of intraoperative hypotension and postoperative urinary retention but also because of the prolonged postoperative stay before home discharge. This is not the case with unilateral spinal anesthesia: motor function returns rapidly, the incidence of urinary retention is extremely low, and patients are usually eligible for home discharge sooner than after bilateral spinal anesthesia or general anesthesia. The success of the technique depends on a number of factors. In addition to the local anesthetic, its concentration and dose, and the baricity of the injected solution, the shape of the spinal needle, the injection speed, the patient's position during injection, and the time the patient remains in this position after injection are equally important parameters. A number of intrathecally applied adjuvant drugs are used to give a more intense and/or longer-lasting block. For this review, we collated the published data on unilateral spinal anesthesia from journals with an impact factor greater than 1.0 and defined an optimized method for performing the technique. In order to achieve an exclusively unilateral block one should use 0.5 % hyperbaric bupivacaine injected at a rate of 0.33 ml/min or slower. During the injection and the following 20 min the patient should lie in the lateral decubitus position on the side intended for surgery with knees drawn to the chest. An injection of 5 mg (1 ml) hyperbaric bupivacaine 0.5 % provides an hour-long block to T 12, and a dose of 7.5 to 10 mg (1.5-2.0 ml) extends the block to T 6. Adding clonidine (0.5 to 1.0 µg/kg BW) to the injection prolongs the duration of the block to approximately two to three hours. During the 20-minute fixation period, the cephalad spread of the block can be influenced to a certain extent by raising or lowering the head of the table.

Hypobaric Unilateral Spinal Anesthesia Versus General Anesthesia for Hip Fracture Surgery in the Elderly: A Randomized Controlled Trial

“…This result could be related to our institutional protocol, which favors patient extubation in the operating room before transfer to the postanesthesia care unit. However, this result is in agreement with those published in a review of the literature on unilateral SA, which concludes that unilateral SA is a rapidly performed anesthetic technique 31 ; in an emergency operating room, this time saving could be useful.…”

A comparative study of unilateral vs bilateral spinal anaesthesia using hyperbaric bupivacaine with buprenorphine in unilateral inguinal hernia surgery

“…Unilateral SAB provides relative hemodynamic stability, rapid return of motor function, and extremely low incidence of urinary retention, and patients are usually eligible for home discharge sooner. So, it could be a better alternative to bilateral spinal anaesthesia [6].…”

A Prospective Randomized Interventional Study to Determine the Influence of Spinal Flexion Versus Extension in the Lateral Decubitus Position on the Unilaterality of Spinal Anesthesia Using Hyperbaric Bupivacaine for Elective Unilateral Lower Limb Surgeries

“…The term unilateral spinal anesthesiais defined as when there is block of only operative side with the absence of block of non-operative side [2]. The fewer hemodynamic changes make unilateral spinal anesthesia suitable for patients with cardiovascular risk factors, for example, aortic valve stenosis or coronary artery disease [3].…”