Critically evaluate  the role of routine daily interruption of sedation  for all mechanically ventilated patients.

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College Answer

      A daily interruption of sedation may have a role in preventing over-sedation and reducing the duration of mechanical ventilation in selected mechanically ventilated ICU patients. (a reasonable opening summary statement)

Evidence:

There are two clinical trials of interruption of sedation that show
o significant reduction in duration of ventilation (0.5)
o duration of ICU stay (0.5)
o fewer CNS investigations. (0.5)
•    Follow up studies suggested that there was a decrease in a range of complications including:
•     VAP, Upper GIT haemorrhage, bacteraemia, venous thromboembolic disease and sinusitis) in patients who received a daily interruption of sedation. (1)
•    There is also a single observational study of longer term outcomes that suggests that a daily scheduled interruption of sedation is not associated with worse psychological outcomes. (0.5)

Candidates were awarded extra  marks  if they mentioned he names of the two big RCTs or if they offered a critical appraisal  of the most recent evidence.
o   Kress 2000 NEJM
and
o   Girard, Lancet 2008 or Awake and Breathing Controlled (ABC) study
o   Critical appraisal of the Girard RCT: appropriate randomisation with
allocation concealment, intention to treat analysis, unblinded

Potential problems:

Routine daily interruption of sedation is not appropriate for all patients, for example;
•    Those with poorly controlled intracranial pressure
•    Those requiring controlled ventilation
•    Those in whom self extubation is particularly dangerous (e.g., those intubated for airway obstruction)
•    Those patients receiving therapy that is likely to be particularly distressing (burns, permissive hypercapnia

Summary statement

•     Due to the risks involved, particularly the risk of self-extubation (10% is a lot!) the use of the protocol would need to be adapted to local circumstances. Studies to date have been performed in the USA. It could be disastrous if a patient self- extubated when there were not sufficiently skilled personnel available to
appropriately manage the patient’s airway.  Thus “routine” daily interruption may not be necessary if the ICU is closed and the level of sedation required is assessed daily by skilled and knowledgeable staff.

Discussion

This question is identical to Question 1 from the first paper of 2013.