International Journal of COPD (Sep 2018)

Bispectral index in hypercapnic encephalopathy associated with COPD exacerbation: a pilot study

  • Chalela R,
  • Gallart L,
  • Pascual-Guardia S,
  • Sancho-Muñoz A,
  • Gea J,
  • Orozco-Levi M

Journal volume & issue
Vol. Volume 13
pp. 2961 – 2967

Abstract

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Roberto Chalela,1–3 Lluis Gallart,4,5 Sergi Pascual-Guardia,1–3 Antonio Sancho-Muñoz,1,2 Joaquim Gea,1–3 Mauricio Orozco-Levi1–3 1Respiratory Medicine Department, Hospital del Mar-IMIM, Barcelona, Spain; 2Department CEXS, Universitat Pompeu Fabra, Barcelona, Spain; 3CIBERES, ISCIII, Barcelona, Spain; 4Department of Anesthesia, Hospital del Mar-IMIM, Barcelona, Spain; 5Universitat Autònoma de Barcelona, Barcelona, Spain Background: Hypercapnic encephalopathy is relatively frequent in severe exacerbations of COPD (ECOPDs), with its intensity usually being evaluated through clinical scales. Bispectral index (BIS) is a relatively new technique, based on the analysis of the electroencephalographic signal, which provides a good approximation to the level of consciousness, having already been validated in anesthesia. Objective: The objective of the study was to evaluate the utility of BIS in the assessment of the intensity of hypercapnic encephalopathy in ECOPD patients. Patients and methods: A total of ten ECOPD patients were included, and the level of brain activity was assessed using BIS and different scales: Glasgow Coma Scale, Ramsay Sedation Scale (RSS), and Richmond Agitation–Sedation Scale. The evaluation was performed both in the acute phase and 3 months after discharge. Results: BIS was recorded for a total of about 600 minutes. During ECOPD, BIS values ranged from 58.8 (95% CI: 48.6–69) for RSS score of 4 to 92.2 (95% CI: 90.1–94.3) for RSS score of 2. A significant correlation was observed between values obtained with BIS and those from the three scales, although the best fit was for RSS, followed by Glasgow and Richmond (r=-0.757, r=0.701, and r=0.615, respectively; P<0.001 for all). In the stable phase after discharge, BIS showed values considered as normal for a wake state (94.6; 95% CI: 91.7–97.9). Conclusion: BIS may be useful for the objective early detection and automatic monitoring of the intensity of hypercapnic encephalopathy in ECOPD, facilitating the early detection and follow-up of this condition, which may avoid management problems in these patients. Keywords: bispectral index, hypercapnic encephalopathy, exacerbation, COPD

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