Assessment of thoracic epidural analgesia during general anesthesia using pupillary reflex dilation: a preliminary study.

Autor: Huybrechts I; Department of Anesthesiology, Erasme University Hospital, Free University of Brussels, Brussels, Belgium. isabelle.huybrechts@ulb.ac.be , Barvais L, Ducart A, Engelman E, Schmartz D, Koch M
Jazyk: angličtina
Zdroj: Journal of cardiothoracic and vascular anesthesia [J Cardiothorac Vasc Anesth] 2006 Oct; Vol. 20 (5), pp. 664-7. Date of Electronic Publication: 2006 Aug 08.
DOI: 10.1053/j.jvca.2006.04.004
Abstrakt: Objective: Pupillary reflex dilation (PRD) secondary to noxious stimulation accurately predicts sensory block during combined lumbar epidural/general anesthesia. Therefore, the adequacy of PRD-guided thoracic epidural infusion during general anesthesia for thoracotomy was studied.
Design: Prospective study.
Setting: University hospital.
Participants: Thirteen patients undergoing thoracotomy.
Interventions: An epidural catheter was placed at the T3-T4 level with initial infusion rate of 5 mL/h of ropivacaine 0.5%. Propofol/remifentanil target-controlled infusion was used for induction and maintenance of general anesthesia. Remifentanil effect site concentration was maintained constant at 0.5 ng/mL during surgery. By using a portable pupillometer, PRD secondary to tetanic stimulation of the C8, T2, and T4 segments were evaluated. Ropivacaine flow rate was adapted half hourly, according to PRD testing and a predefined algorithm. At the end of surgery, PRD was tested in the 3 investigated segments, and general anesthesia was stopped. After emergence, these zones were tested for their sensitivity to cold. Pain was evaluated by using the visual analog scale.
Results: Pain scores were <3 of 10 in 84.6% of the patients. Mean PRD was 0.9 +/- 0.6 mm in unblocked levels versus 0.2 +/- 0.5 mm in blocked segments (p = 0.02). PRD >or= 0.5 mm was predictive of incomplete block (sensitivity 76%, specificity 79%, and positive predictive value 86%). PRD >or= 1 mm was highly predictive of inadequate block (sensitivity 73%, specificity 91%, and positive predictive value 94%).
Conclusion: PRD-guided continuous thoracic epidural analgesia under low-dose remifentanil/propofol anesthesia is feasible and ensures good postoperative analgesia.
Databáze: MEDLINE
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