Effect of epidural dexmedetomidine on intraoperative awareness and post-operative pain after one-lung ventilation.
BACKGROUND
During combined general and regional anaesthesia, it is difficult to use autonomic signs to assess whether wakefulness is suppressed adequately. We compared the effects of a dexmedetomidine-bupivacaine mixture with plain bupivacaine for thoracic epidural anaesthesia on intraoperative awareness and analgesic benefits, when combined with superficial isoflurane anaesthesia (<0.05 maximum alveolar concentration) in patients undergoing thoracic surgery with one-lung ventilation (OLV).


METHODS
Fifty adult male patients were randomly assigned to receive either epidural dexmedetomidine 1 microg/kg with bupivacaine 0.5% (group D) or bupivacaine 0.5% alone (group B) after induction of general anaesthesia. Gasometric, haemodynamic and bispectral index values were recorded. Post-operative verbal rating score for pain and observer's assessment of alertness/sedation scale were determined by a blinded observer.


RESULTS
Dexmedetomidine reduced the use of supplementary fentanyl during surgery. Patients in group B consumed more analgesics and had higher pain scores after operation than patients of group D. The level of sedation was similar between the two groups in the ICU. Two patients (8%) in group B reported possible intraoperative awareness. There was a limited decrease in PaO2 at OLV in group D compared with group B (P<0.05).


CONCLUSIONS
In thoracic surgery with OLV, the use of epidural dexmedetomidine decreases the anaesthetic requirements significantly, prevents awareness during anaesthesia and improves intraoperative oxygenation and post-operative analgesia.
Elhakim
M
M
Department of Anaesthesia, Faculty of Medicine, Ain-Shams University, Cairo, Egypt. mokhtar.elhakim@gmail.com
Abdelhamid
D
D
Abdelfattach
H
H
Magdy
H
H
Elsayed
A
A
Elshafei
M
M
D000316:Adrenergic alpha-Agonists / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D000328:Adult; D018712:Analgesics, Non-Narcotic / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D000767:Anesthesia, Epidural; D000768:Anesthesia, General; D018685:Anesthetics, Inhalation / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology; D001364:Awareness / Q000187:drug effects*; D002045:Bupivacaine / Q000008:administration & dosage; D056805:Consciousness Monitors; D020927:Dexmedetomidine / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D006993:Hypnotics and Sedatives / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D000860:Hypoxia / Q000139:chemically induced / Q000517:prevention & control; D007431:Intraoperative Complications / Q000453:epidemiology / Q000517:prevention & control*; D007530:Isoflurane / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology; D008297:Male; D008875:Middle Aged; D010149:Postoperative Pain / Q000188:drug therapy / Q000517:prevention & control*; D012121:Respiration, Artificial / Q000379:methods*; D016037:Single-Blind Method; D019616:Thoracic Surgical Procedures
D000316:Adrenergic alpha-Agonists; D018712:Analgesics, Non-Narcotic; D018685:Anesthetics, Inhalation; D006993:Hypnotics and Sedatives; D020927:Dexmedetomidine; D007530:Isoflurane; D002045:Bupivacaine