Segmental Epidural Anaesthesia for Percutaneous Kyphoplasty

After obtaining local research ethical committee approval, fifty two ASA class I to III patients aged over 18 years scheduled for percutaneous kyphoplasty were recruited to the study. Severe systemic disease includes ASA class IV or more, pathology in cervical vertebra, known allergy to the study drugs, any contraindication for performing the epidural anaesthesia (bleeding diathesis, anticoagulation, hypovolemia, infection at the site of injection, increased intracranial pressure, severe aortic stenosis, severe mitral stenosis), presence of pregnancy, and cognitive disorders that preventing the cooperation were accepted as exclusion criteria. Patients requiring more than one level of intervention were excluded, also. Written informed consent was taken from the patients. Vascular access was found on the dorsum of the hand and crystalloid fluid infusion was started at a rate of 6 ml/kg/hour. Midazolam 1-1.5 mg was given intravenously as premedication. Patients were monitored for standard electrocardiography (ECG), blood pressure non invasively and peripheral oxygen saturation (SpO2) in the operating room. The patients were randomly allocated, using sealed envelopes, to one of the following 2 groups: 1. Group 1 (Group Epidural, n=26): Patients were placed in sitting position. After skin preparation, local anaesthesia was performed with 2 ml of lidocaine 2%. Segmental epidural anaesthesia was performed using loss of resistance technique with saline. Tuohy needle was introduced into the intervertebral space one segment lower than that of affected one. Aperture of the needle was directed to cranial and 0.5 % concentration of levobupivacaine of 1.25 ml per segment for thoracal and 1.5 ml per segment for lumbar approach was administered. Patients were placed in prone position. Analgesia of the surgical area was assessed using pinprick test. Operation was allowed when adequate analgesia was determined with pinpricks on at least two upper and two lower dermatomal levels of intervention, and it required approximately 15 minutes. Sedation was performed with midazolam 1-1.5 mg intravenously and fentanyl was given as 25 micro.g bolus doses if supplemental analgesia was necessary especially during trocar insertion. In the case of insufficient skin analgesia, general anaesthesia would be performed and the patient would be excluded from the study. 2. Group 2 (Group Control, n=26): General anaesthesia was performed in this group. After preoxygenation, propofol 2 mg/kg and rocuronium bromide 0.6 mg/kg was given for the induction. Endotracheal intubation was applied and anaesthesia was maintained with end tidal 2-2.5% concentration of sevoflurane in nitrous oxide-oxygen mixture (FiO2= 35%). Patients were ventilated with volume-controlled ventilation (Drager Primus, Lubeck, Germany). The respiratory rate was set to maintain an end-tidalCO2 between 4-4.5 kPa. After completation of the surgery, inhalation anaesthesia was discontinued. If adequate spontan ventilation (more than 6 mL/kg) was achieved, endotracheal tube was removed. Patients were observed until cooperation was achieved and then transferred to the post anaesthetic care unit (PACU). Haemodynamic parameters were recorded every 5 minutes during intraoperative and postoperative period. Patients were transferred to the ward when Modified Aldrete Score was greater than or equal to 9. Pain was assessed by an investigator who was blinded to the study groups at hourly intervals during postoperative 4 hours, and postoperative 24. hour. Pain was assessed by using a standard two sided plastic millimetric scale, ranging from 0 mm:no pain to 100 mm: worst pain imaginable. When VAS (visual analog scale) pain scores exceed 30 mm, dexketoprofen tromethamole 50 mg was infused and paracetamol 1 g was given intravenously when the VAS score was persistently higher than 30 mm in the following visit. If these treatments were inefficient, tramadol hydroclorur 25 mg was administered intravenously and repeated as required. Postoperative analgesic requirements, VAS scores, length of stay in PACU and complications were recorded.