Post- Thoracotomy Paravertebral Block

Safety and Efficacy of Ultrasound Guided Paravertebral Dexmedetomidine for Postoperative Pain Relief in Video Assisted Thoracoscopy Surgery

Postoperative pain is the most undesired consequence of surgery, and if not managed adequately, can lead to delayed recovery and increased hospital stay. Surveys continue to reveal that postoperative pain is insufficiently managed throughout the first world, let alone in the Third World. An American survey over 20 years showed that only one in four patients had adequate relief of postoperative pain. This has led recovery room protocols to include pain as a fifth vital sign that needs to be addressed before patients are discharged to the ward

This prospective, randomized, double-blinded, parallel assignment clinical trial will be done after receiving approval from the local ethics committee of the Faculty of Medicine, Assiut University. A written informed consent will be taken after discussing a detailed description of the study with the patients. Patients will be allocated randomly into two equal groups by computer programs and will be contained in sealed opaque envelopes. Patients will be premedicated with midazolam (0.1mg/kg), 30 min before the operation. Patients will be monitored with ECG, non-invasive blood pressure, heart rate, temperature, oxygen saturation, exhaled CO2 (end tidal capnography), and train of four. In both groups, general anesthesia will be induced with propofol (2mg/kg) and fentanyl (1 mcg/kg). Tracheal intubation will be facilitated with cisatracurium 0.1 mg/kg. Anesthesia will be maintained with isoflurane (1-2 %) and cisatracurium (0.05 mg/kg per dose). Fentanyl (0.5mcg/kg) will be repeated if heart rate (HR) and/or mean arterial pressure (MAP) rise 20 % above baseline values. After the end of anesthesia induction and before surgical procedure Technique of ultrasound guided paravertebral block will be done in both groups.

Ultrasound guided paravertebral block with bupivacaine group Thirty patients will be given isobaric bupivacaine 0.5% (0.3ml/kg) via paravertebral route.

Ultrasound guided paravertebral block with bupivacaine and dexmedetomidine group Thirty patients will be given isobaric bupivacaine 0.5% (0.3ml/kg) and dexmedetomidine (1 mcg/kg) via paravertebral route (Bupivacaine plus Dexmedetomidine)

5. Pain scores at rest and on coughing will be recorded using visual analogue scale (VAS) pain intensities at rest and during coughing/movement assessed by VAS score. The quality of effective analgesia will be expressed as VAS values derived from the VAS pain score, at rest and during coughing during each assessment period (2 h, at 4, 8 and 24 h).

Inclusion Criteria: ASA I, II and III. In the age ranged between 18 up to 60 years. Elective video-assisted thoracoscopy Exclusion Criteria: ASA IV and V Liver impairment Renal impairment allergy to the drugs used Known contraindication for regional techniques such as: Infection near the site of the needle insertion Coagulopathy Anti-coagulation therapy,