From the Guidelines
For depth of anesthesia (DOA) monitoring, the recommended target is a Richmond Agitation and Sedation Scale (RASS) score of -2 to 0 or a Sedation-Agitation Scale (SAS) score of 3 to 4, which indicates a light level of sedation and the ability to follow commands without agitation. This target range is based on the most recent and highest quality study, which suggests that maintaining lighter levels of sedation in ICU patients is associated with improved clinical outcomes 1. The RASS and SAS scales are the most valid and reliable instruments for assessing adequacy and depth of sedation, and should be used to guide sedation management in critically ill patients 1.
Some key points to consider when targeting this range include:
- Assessing agitation and sedation regularly, using tools such as the RASS or SAS scales
- Using non-benzodiazepines as first-line sedatives, unless there is a specific indication for benzodiazepines, such as alcohol or benzodiazepine withdrawal
- Titrating sedatives to maintain a light level of sedation, and using daily sedative interruption or sedation protocols to facilitate management of pain, sedation, and delirium
- Monitoring patients for delirium, and using strategies such as early mobilization and optimizing the patient's environment to reduce the incidence and duration of delirium 1.
By targeting a RASS score of -2 to 0 or an SAS score of 3 to 4, clinicians can help to improve patient outcomes, reduce the risk of delirium and other complications, and provide more effective and efficient sedation management in the ICU.
From the FDA Drug Label
The FDA drug label does not answer the question.
From the Research
Targets for Depth of Anaesthesia (DoA) Monitoring
The following targets are recommended for monitoring depth of anaesthesia:
- Blood pressure 2
- Pulse oximetry 2
- EKG 2
- Respiratory rate 2
- Oxygen saturation 2, 3
- Level of consciousness 4, 3
- Sedation level 5, 3
Monitoring Parameters
Monitoring parameters for DoA include:
- Heart rate 3
- Non-invasive systolic, diastolic, mean arterial blood pressure 3
- Oxygen saturation (SPO2) 3
- Bispectral Index (BIS) score 3
- Ramsay Sedation Scale (RSS) score 3
Correlation Between Monitoring Parameters
A strong correlation has been observed between BIS and RSS scores in elderly patients undergoing urological procedures under spinal anaesthesia 3. The correlation coefficient between BIS and RSS scores indicates a strong correlation with a magnitude of 70%-80% 3.
Depth of Anaesthesia Monitors
Ideal DoA monitors should be able to suggest personalised drug dosage, predict and provide early warnings when dosages are inappropriate, be portable, and highly cost-effective 6. The latest research results show that the performance of DoA monitors can be improved using up-to-date computing technology and neurophysiology 6.