Porównanie oceny klinicznej głębokości znieczulenia ogólnego z monitorowaniem za pomocą indeksu bispektralnego

Ewa Wojcieszek¹, Elżbieta Wojarska-Tręda¹, Wanda Woźniakowska¹, Zofia Kołosza¹, Anna Dyaczyńska-Herman², Bożena Lassota-Korba¹

Summary
Background. The bispectral index (BIS) is a continuous processed electroencephalography parameter that has been developed to measure the hypnotic effects of anaesthetic and sedative agents on the brain. The aim of the study was to compare common clinical methods of assessment of the depth of anaesthesia, such as blood pressure (SAP) and heart rate (HR) with BIS index readings. Methods. Thirty adult ASA 1-3 patients, scheduled for thyroidectomy or mastectomy, were included in the study. Anaesthesia was commenced with propofol, titrated to loss of the eyelash reflex. For maintenance, continuous infusion of propofol (1-6 mg kg^-1 h^-1) and nitrous oxide were used. 15 patients in group I received intermittent bolus doses of fentanyl and the other 15, in group II, received a continuous remifentanil infusion (0.1-0.8 ?g kg^-1 min^-1). The depth of anaesthesia was adjusted according to the standard clinical signs of adequacy of anaesthesia including tachycardia, increased blood pressure, sweating, and lacrimation, by an anaesthesiologist blinded to the BIS scores. A 20% increase in blood pressure and/or heart rate were regarded as signs of inadequate anaesthesia. BIS readings, SAP and HR were noted every 5 minutes. The recovery time and the time to return of preoperative baseline cognitive function were assessed by OAAS score. Mann-Whitney and Wilcoxon tests were used for statistical analysis. Results. The average BIS scores during intubation were higher in the fentanyl group (76.6±23.46 vs. 59.5±20.79), but the difference was not statistically significant. Clinical assessment indicated an appropriate depth of anaesthesia. Average OAAS score in group I was 3.5±1.99 vs. 4.13±0.99 in the group II. The difference between the two groups was not statistically significant. During anaesthesia, there were no differences between the groups, in BIS readings or clinical parameters. The association between the clinical assessment and the BIS index was far from being ideal. Discussion and conclusion. BIS monitoring may be a useful adjunct in monitoring during various types of anaesthesia. It is especially useful during severe nociceptive stimulation and recovery, allowing for more precise assessment of the clinical situation.

To jest tylko fragment artykułu. Aby przeczytać całość, przejdź do Czytelni medycznej.