title: A comparison of thoracic spinal anesthesia with low-dose isobaric and low-dose hyperbaric bupivacaine for orthopedic surgery: A randomized controlled trial.
abstract: BACKGROUND
  The thoracic spinal anesthesia was first described in 1909 and recently revised for various surgical procedures. This is a prospective study aims to evaluate the parameters of the thoracic spinal anesthesia (latency, motor block and paresthesia), the incidence of cardiovascular changes and complications comparing low doses of isobaric and hyperbaric bupivacaine.
  
  
  METHODS
  A total of 200 orthopedic patients operated under spinal anesthesia were included in this study. Spinal anesthesia was between T9-T10, with a 27G cutting point or pencil tip in lateral or sitting. Spinal anesthesia was performed with 0.5% bupivacaine isobaric or hyperbaric. Patients remained in cephalad or head down position 10-20° for 10 minutes. We evaluated the demographics, analgesia, and degree of motor block, incidence of paresthesia, bradycardia, hypotension, anesthesia success and neurological complications.
  
  
  RESULTS
  All patients developed spinal and there was no failure. The solution did not affect the onset of the blockade. The duration of motor block was greater than the sensitive with isobaric. The duration of sensory block was greater than the motor block with hyperbaric solution. The incidence of paresthesia was 4%, with no difference between the needles. The incidence of hypotension was 12.5% with no difference between the solutions. There was no neurological damage in all patients.
  
  
  CONCLUSIONS
  The beginning of the block is fast regardless of the solution used. By providing a sensory block of longer duration than the motor block hyperbaric bupivacaine is reflected in a better indication. Thoracic spinal anesthesia provides excellent anesthesia for lower limb orthopedic surgery.
authors.affiliation: Department of Anesthesiology, Faculty of Medicine Nova Esperança, João Pessoa, Paraíba ; Director of the Institute for Regional Anesthesia, Brazil.
authors.forename: Luiz Eduardo
authors.initials: LE
authors.lastname: Imbelloni
authors.affiliation: Director of the Institute for Regional Anesthesia, Brazil.
authors.forename: Marildo A
authors.initials: MA
authors.lastname: Gouveia
keywords: Thoracic spinal anesthesia; bupivacaine isobaric; complications; hyperbaric bupivacaine; local anesthetic