Effect of propofol and remifentanil on a somatosensory evoked potential indicator of pain perception intensity in volunteers

• Type: Article in International Scientific Journal
• Date: 2015

Authors

Fernando Gomes Almeida (Author) FEUP; Ana Castro (Author) FEUP; Catarina S. Nunes (Author) Other; Pedro Amorim (Author) ICBAS

Journal

Title: Journal of Clinical Monitoring and Computing

Vol. 29 No. 5

Pages: 561-567

ISSN: 1387-1307

Publisher: Springer Nature

Indexing

ISI Web of Knowledge - 4 Citations

ISI Web of Science

Scopus - 4 Citations

Other information

Authenticus ID: P-00F-ZJQ

DOI: 10.1007/s10877-014-9632-0

Abstract (EN): Somatosensory evoked potentials (SEPs) have been linked to noxious activation and stimulus intensity. In this exploratory study we investigated the impact of anaesthetic drugs on SEPs and pain ratings, to assess their applicability as an objective measure of the nociception/anti-nociception balance. Following institutional approval and written informed consent, 10 healthy adult volunteers were enrolled (29.5 +/- A 9.1 years, 63.0 +/- A 8.9 kg and 171.4 +/- A 7.2). Median nerve electrical stimulation was adjusted according to volunteers' sensitive, motor and painful thresholds (PT). Baseline SEPs were registered, and remifentanil and propofol administered using a stair scheme TCI. For each drug combination a 1.3xPT stimulus was administered, and volunteers evaluated pain intensity in a numerical rating scale (0-10). SEPs' amplitudes and latencies were normalized by the baseline values, reducing volunteers' intervariability. Stimulation currents varied between 6-52 mA (1.3xPT) and pain ratings between 0 and 9. Cortical SEPs latencies were decreased for higher stimulus intensities (P < 0.01), accompanied by increased pain ratings (P < 0.01). An individually adjusted/normalized ratio based on cortical SEPs amplitude and interpeak latency is proposed(): and NSR were significantly correlated in three out of nine subjects, and and remifentanil Ce were significantly correlated in two (low number of evaluation points). was shown to decrease with increasing doses of propofol and remifentanil (P < 0.05). The proposed metric was depressed by anaesthetics and reflected pain evaluations. Further research is necessary to increase the number of volunteers and drugs' combination, to assess its applicability during surgically adequate anesthetic leves.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 7