Forum.
Literature Review
We searched the databases MEDLINE, EMBASE, CINAHL, Allied & Complementary Medicine, British Nursing Index, and PsycINFO using the words sedation, conscious sedation, palliative care, dying, monitor, family, support, communication, clinical trial. Although we had over 200 “hits” with this search strategy, we found no clinical trials.
Morita et al emphasized the importance of family communication and support when considering sedation for symptom control . No mention is made of monitoring, although it is perhaps implied in two of three case examples presented. Müller-Busch et al retrospectively reviewed, with respect to sedation at end of life, the medical records of 548 patients who died in their palliative care unit . Sedated patients were still rated for symptom control, and note was made of the patients’ states of consciousness and communication skills, indicating that some sort of monitoring of depth of sedation had occurred. The results given are not comprehensive but 66% of patients were taking oral fluids, indicating a light level of sedation. This is also implied by the fact that 50% of the sedated patients were able to request help, or report symptoms. Healthcare staff aimed to give the patient good sleep at night and a “more patient-controlled sedative state with communicative skills and reports of comfort during the day”. 50% of patients were able to communicate and ask for help or answer questions. A Taiwanese study monitored sedated patients for adequate symptom relief, but does not refer to other aspects of monitoring a sedated patient .
There are guidelines for sedation under varying circumstances. Cherney and colleagues suggest that patient monitoring at end of life should depend on the goal of care. For example, if the aim is comfort, then comfort, rather than vital signs, should be monitored. If the patient is not imminently dying and wishes to be left sedated at a certain level, then comfort and level of sedation can be monitored.
Guidelines and recommendations exist for conscious sedation during procedures e.g. gastro-intestinal endoscopy , but here the priority is given to monitoring vital signs. In the ICU monitoring is often more intense. Devlin et al reviewed methods for assessing sedation in critical ill adults and found 23 assessment instruments . Of these, only six had been evaluated for validity and seven for reliability, and he concludes that these instruments need further evaluation.
Level of consciousness can be measured using the Glasgow Coma Scale (GCS), which was designed to grade the severity of impaired consciousness in patients with traumatic head injuries and after intracranial surgery. Unfortunately, the assessment involves the response to painful stimuli, which is not appropriate for palliative care patients. The GCS is commonly used to assess level of consciousness of patients in the early and/or minimal response phases after suspected brain injury.
The Richmond Agitation-Sedation Scale (RASS) has been validated in the intensive care setting in patients on mechanical ventilation. It is a 10-point scale using observation, verbal stimulation, and physical stimulation, the last used only to assess the two (out of five) deepest levels of sedation.
The Sedation-Agitation Scale (SAS) provides a symmetric approach to grading patient behaviour. There are three severity levels each for sedation and agitation and one level for the calm patient. Behavioral descriptors provide clinicians assistance with assigning scores.
The Motor Activity Assessment Scale (MAAS) is an entirely observational assessment scale also validated for use in the mechanically ventilated patients. It is a 0-6 scale ranging from unresponsive to dangerously agitated and uncooperative.
The Ramsay Scale has been used for the last 20 years, although it lacks behavioural descriptors to help with assigning a score, and is also an observational 6-point scale.
- The Disorders of Consciousness Scale recently developed by scientists at Chicago's Northwestern University is another scale that involves physical stimulation of the patient and is designed to predict the recovery of consciousness up to one year after injury, with up to 86 percent certainty 16. ( A measure of neurobehavioral functioning after coma. Part I: Theory, reliability, and validity of the Disorders of Consciousness Scale. Journal of Rehabilitation Research & Development Volume 42, Number 1, January/February 2005 p1-18. )
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