Critical care, neurology and analgesia
Evelyne Jacqz-Aigrain, Imti Choonara in Paediatric Clinical Pharmacology, 2021
Assessment of the electroencephalogram (EEG) offers the potential for continuous, non-invasive measurement of brain function. The bispectral index is derived from the EEG, using a sophisticated algorithm, that uses the advanced signal processing of bispectral and power spectral variables in a multivariate analysis to produce a bispectral index number. The bispectral index monitor uses bispectral indexing to calculate a processed multivariate parameter on a scale from 0 (no brain activity) to 100 (fully awake) and has proved useful in monitoring the depths of anesthesia and sedation in the intensive care unit. Poor skin contact, muscle activity or rigidity, head and body motion, sustained eye movements, improper sensor placement or skin preparation, and unusual or excessive interference may cause potential artefacts. Some drugs also affect the bispectral index number; for any given level of sedation, the administration of ketamine causes an increase in the bispectral index number, whilst the administration of nitrous oxide causes a decrease in the bispectral index number.
Processing of Data
Abhaya Indrayan in Research Methods for Medical Graduates, 2019
An index is quantitative and therefore involves calculation that could be a nemesis for some clinicians. Some indexing instruments come ready with software to perform the calculations and directly provide the results. A bispectral index is automatically calculated by software. A high-pressure liquid chromatography automatically calculates the peak area of intensity of signals corresponding to concentrates of drug-evoked potentials. Thus, for some indexes, calculations are not much of a problem. Perhaps a greater problem is their validity and reliability. These two concepts are briefly explained in Chapter 7. A large number of indexes is available and many are being devised every year, but studies that provide evidence of their reliability and validity for different segments of population are rare. For example, the utility of BMI is sometimes questioned in comparison with the waist–hip ratio, which can be seen as a better correlate of coronary events. Thus, the choice of an index can be an issue in situations where two or more indexes are available to assess the same aspect of health, and you need to be judicious in making the choice.
Neuropharmacology: Age-related changes
Hemanshu Prabhakar, Charu Mahajan, Indu Kapoor in Essentials of Geriatric Neuroanesthesia, 2019
Postoperative cognitive dysfunction (POCD) is defined as cognitive decline after surgery and anesthesia (33). Evidence suggests that POCD could develop from amyloid deposition and tau protein. In addition to surgery, other risk factors include age and history of stroke, while cerebral hypoperfusion, duration of anesthesia, and alterations in neurotransmitters increase risk as well. Elderly are more susceptible to POCD, which can present transiently with fluctuating symptoms or follow a more permanent and consistent pattern. Unfortunately, these changes significantly worsen recovery and increase hospital length of stay. Up to 40% of adults will experience some type of POCD postoperatively, with up to 10% of elderly patients having persistent dysfunction after 3 months (53). Preclinical data involving propofol and volatile anesthetics indicate that these agents may cause POCD; however, the evidence is controversial. Bispectral index monitoring is of interest in the elderly population during surgical procedures, as it appears to result in lower total anesthetic doses and less incidence of POCD (33,54).
The maximum value of bispectral index predicts outcome in hypoxic-ischemic encephalopathy after resuscitation, better than minimum or mean value
Published in Brain Injury, 2018
Wenli Miao, Qing Sun, Hongdao Wang, Hailing Li
Bispectral index (BIS) is a non-invasive and real-time measurement of simplified electroencephalographic data and is applied more widely than electroencephalogram (EEG) in critical care because of its objectiveness and practicality. Since BIS has been reported effective in predicting prognostic outcome of patients with brain injury (3–5), evaluating effectiveness on chest compression during CPR (6), the possibility of its application on predicting the severity of brain injury, even the mortality among patients with HIE after CPR, was proposed (7–9), for which, however, the conclusion is not determined (10). Presumably, higher BIS values stand for better neurological outcomes (11); meanwhile, lower BIS values represent the poorer (12). However, which of the BIS values, maximum (BISmax), minimum (BISmin) or mean (BISmean), whatever solely or jointly, should be considered the most dependable in predicting the outcomes among patients with HIE is highly controversial. The study we conducted herein is to provide more clinical evidence in evaluating the practicality of value of BIS on clinical cases with HIE after CPR.
Assessment of sedation level for endoscopic retrograde cholangiopancreatography – a prospective validation study
Published in Scandinavian Journal of Gastroenterology, 2018
Jarno Jokelainen, Harri Mustonen, Leena Kylänpää, Marianne Udd, Outi Lindström, Reino Pöyhiä
Bispectral index (BiS) monitoring is an electroencephalogram (EEG) based-method which analyzes the EEG signal with an algorithm that produces a simple index score that was developed to assess the depth of general anesthesia, but has also been used to monitor the depth of sedation. BiS has been used in studies on ERCP sedation with some success [4–7]. Other methods of assessing the depth of sedation for ERCP have also been used in studies, such as the Richmond Agitation/Sedation Scale (RASS) [8], a modified Ramsay Sedation Scale (mRSS) [9] and modified Observer Assessment of Alertness and Sedation (mOAAS) [4,6]. These are all assessed by clinical evaluation and by verbal, tactile or painful stimuli. Also, these scales are designed to be used in intensive care units and may not be ideal for use during procedural sedation. This study was performed in order to evaluate the usefulness and practicality of the aforementioned methods of assessing the depth of sedation during ERCP.
Pre-, Peri-, and Postoperative Intravenous Ropivacaine versus that of Lidocaine for Analgesia after Hand-Assisted Laparoscopic Surgery of Left Colon Cancer: A Retrospective Analysis
Published in Journal of Investigative Surgery, 2021
All patients were subjected to general anesthesia under 2 mg/kg propofol (Diprivan®, Aspen Pharma Trading Limited, Dublin, Ireland) and 1.5 µG/kg fentanyl (Siegfried Hameln GmbH, Hameln, Germany). Tracheal intubation was performed with rocuronium (Hospira, Inc., Lake Forest, IL, USA). A 0.45 mg/kg intraoperative bolus atracurium (Hikma Farmaceutica (Portugal), S.A, Terrugem SNT, Portugal) was administered and monitored using a nerve stimulator. Heart rate and arterial blood pressure were maintained within 25% of the baseline value. If heart rate and/or arterial blood pressure were increased by 25% of the baseline value, 50 µG of fentanyl was administered. If heart rate and/or arterial blood pressure were decreased by 25% of the baseline value, epinephrine (EpiPen®, Mylan N.V., Canonsburg, Pennsylvania, USA) was administered. Anesthesia was maintained with sevoflurane (Ultane, AbbVie Inc., Chicago, IL, USA) in 40% air and 60% oxygen mixture. The bispectral index was maintained within the range of 40–60 [3]. Twenty-four-hour postoperative analgesia in the surgical intensive care unit and/or the ward was maintained by 100 mL infusion of paracetamol (10 mg/mL, Accord Healthcare Ltd., North Harrow, HA1 4HF, UK; maximum four infusions per day and maximum for 3 days) [10].
Related Knowledge Centers
- Monitoring
- Anesthesia
- Guedel'S Classification
- General Anaesthetic
- Anesthesia Awareness
- Ketamine
- Nitrous Oxide
- Consciousness
- Electroencephalography
- General Anaesthesia