From the Guidelines
The recommended BIS range for propofol sedation is 40-60 for general anesthesia, as stated in the most recent and highest quality study 1. This range is crucial in preventing awareness during anesthesia and excessive sedation. When administering propofol, clinicians should titrate the dose to achieve the target BIS value appropriate for the clinical situation. For general anesthesia, propofol is typically initiated at 1-2.5 mg/kg for induction, followed by 100-200 mcg/kg/min for maintenance, adjusting as needed to maintain the desired BIS range. BIS monitoring provides a numerical value from 0-100 that correlates with depth of sedation, with lower numbers indicating deeper sedation. Some key points to consider when using BIS monitoring with propofol include:
- Maintaining a target BIS range between 40 and 60 can reduce the risk of awareness in high-risk patients 1
- The use of BIS or newer burst suppression monitoring to avoid overdose of anesthesia in the elderly may have a role in reducing the risk of postoperative delirium and postoperative cognitive dysfunction in this patient population 1
- Propofol TIVA may reduce PONV in certain patients, but no definitive recommendation can be made for this currently 1
- The use of short-acting inhalational agents such as sevoflurane or desflurane in oxygen-enriched air is standard practice around much of the world 1
- Nitrous oxide is normally avoided due to its delaying effects on the bowel, although the increased risk of PONV can be markedly reduced with standard PONV prophylaxis 1
From the Research
BIS Values for Propofol
- The bispectral index (BIS) is a processed EEG parameter used to measure the pharmacodynamic anesthetic effect on the central nervous system 2.
- BIS values range from 0 to 100, with 0 indicating no cerebral activity and 100 indicating a fully awake patient 2.
- During propofol-induced sedation, BIS values may be maintained above 75 to prevent airway obstruction and hypoxia 2.
- For propofol intravenous anesthesia, BIS values between 40 and 60 are proposed to maintain the desired level of hypnosis, with values below 50 associated with an insignificant probability of recall 2.
Target BIS Ranges
- A study found that using BIS monitoring to guide propofol administration resulted in a decrease in overall rates of propofol administration and fewer incidences of oversedation 3.
- Another study suggested that BIS values between 40 and 60 are suitable for maintaining hypnosis during propofol anesthesia 2.
- A target BIS range of around 50 was used in a study to guide propofol induction of anesthesia, resulting in a reduction of propofol requirement without side effects 4.
Correlation between BIS and Propofol Concentrations
- Significant correlations between plasma propofol concentrations and BIS values have been reported, with correlation coefficients ranging from 0.68 to 0.78 2.
- A study found that higher BIS values were correlated with higher propofol concentrations, with 95% of propofol target concentrations between 1.5 and 3.5 µg·mL-1 5.