The Pros And Cons Of Spinal Anaesthesia

Spinal anaesthesia is a routinely used anaesthetic technique in patients undergoing operations involving the lower limbs, lower abdomen, pelvis and the perineum[1,2,3]. Spinal anaesthesia has several advantages over general anaesthesia including stable haemodynamic variables, less blood loss, less post-operative pain, faster recovery time and less post-operative confusion
It involves the use of small amounts of local anesthetic injected into the subarachnoid space to produce a reversible loss of sensation and motor function. The injection of local anesthetic in the subarachnoid space can result in hemodynamic and respiratory changes.
Along with the analgesia, anesthesia and motor blockade, spinal anesthesia also induces a sympathetic block that may cause hypotension, bradycardia, nausea, vomiting, dysrhythmias and rarely, cardiac arrest[4]. If it were possible to limit anesthesia for the surgical field certain undesirable effects of spinal anesthesia could be avoided.
Among such techniques are fractional segmental spinal analgesia,[7,8,9,10] where localization is achieved by intermittent injection of small amounts of agents into the subarachnoid space via an indwelling catheter or needle, and unilateral spinal analgesia,[11, 12, 13] where anesthesia is confined to one side of the body by the subarachnoid administration of hypobaric or hiperbaric solutions with the patient placed in the lateral position. In 1961, Tanasichuk et al.[14] described a particular technique of spinal anesthesia in patients receiving one limb orthopedic surgery, which they named spinal hemianalgesia. In practice, a conventional unilateral spinal anesthesia technique can only result in a motor hemi-block and a sensory block preferential to one