Title

Alpha 2 Agonists for Sedation to Produce Better Outcomes From Critical Illness (A2B Trial)
Alpha 2 Agonists for Sedation to Produce Better Outcomes From Critical Illness (A2B Trial): A Randomised, Parallel-group, Allocation Concealed, Controlled, Open, Phase 3 Pragmatic Clinical and Cost- Effectiveness Trial With Internal Pilot
  • Phase

    Phase 3
  • Study Type

    Interventional
  • Status

    Recruiting
  • Study Participants

    1737
Many patients in intensive care (ICU) need help to breathe on a breathing machine and need pain killers and sedatives to keep them comfortable and pain free. However, keeping patients too deeply sedated can make their ICU stay longer, can cause ICU confusion (delirium) and afterwards may cause distressing memories. Ideally patients should be kept less sedated, but it is difficult to get the balance of sedation and comfort right.

The investigators want to know whether starting an alpha2-agonist drug early in ICU can help keep patients more lightly sedated but still comfortable, and whether patients spend less time on the ventilator. The investigators also want to know how safe they are and if they can improve important outcomes during ICU stay and during recovery. The investigators also want to know if they are value for money.
Many patients in intensive care (ICU) need help to breathe on a breathing machine and need pain killers and sedatives to keep them comfortable and pain free. However, keeping patients too deeply sedated can make their ICU stay longer, can cause ICU confusion (delirium), and afterwards may cause distressing memories. Ideally, the investigators want to keep patients less sedated, but it is difficult to get the balance of sedation and comfort right.

For sedation, most ICUs use a drug called 'propofol' that is good at reducing anxiety and making people sleepy, but is not a pain killer, so additional pain killers are needed. There are two other drugs used less often called 'alpha-2 agonists' that have both sedative and pain-killing actions, which may make it easier for patients to be more awake and comfortable on the ventilator. The two drugs are called clonidine and dexmedetomidine.

The investigators want to know whether starting an alpha2-agonist drug early in ICU, and using this instead of propofol as much as possible, can help keep patients more lightly sedated but still comfortable, and whether patients spend less time on the ventilator with these drugs. The investigators also want to know how safe these drugs are and if improve important outcomes during ICU stay can be improved (like delirium, comfort, and safety) and during recovery (like bad memories, anxiety, and depression). The investigators also want to know if they are value for money.

The trial will include 1737 participants needing to be on a ventilator for at least 2 days. Participants will be allocated to one of three groups by chance. One group will continue to receive propofol; one group will receive dexmedetomidine; and one group will receive clonidine. All participants will receive extra pain relief if needed, and participants in the dexmedetomidine and clonidine groups will continue to receive propofol if they need this in addition. Nurses and doctors will alter the doses of sedation drugs to try and reduce or stop them, but always aiming to have participants lightly sedated and comfortable. The trial will compare if participants on dexmedetomidine or clonidine come off the ventilator quicker than those just on propofol. The trial will examine whether there was a difference between the groups in the number of participants who experienced delirium in ICU, compare how comfortable participants were, and measure if participants memories of being in the ICU differed.

Patients who were in the trial will be followed up for 180 days afterwards because the investigators want to compare if there were differences in the after-effects of being ill in ICU between the groups. Participants will be asked to complete questionnaires that will assess their memories of the ICU experience at 30 and 90 days after entering the trial. At 90 and 180 days, participants will be asked to complete questionnaires so that the investigators can detect how patients feel about their quality of life or if they suffer from anxiety, depression or stress.

Alongside this trial, investigators will be looking at value for money, which is important because clonidine, dexmedetomidine, and propofol costs are quite different. Clonidine, in particular, is relatively inexpensive. ICU nurses' and doctors' views on how easy or difficult it was to adjust and use the drugs will be obtained. This will give valuable practical information that can be shared with other ICUs, particularly if alpha2-agonists are found to be better and other ICUs want to start using them.
Study Started
Dec 10
2018
Primary Completion
Nov 30
2022
Anticipated
Study Completion
May 31
2023
Anticipated
Last Update
Mar 28
2022

Drug Dexmedetomidine

Patients will commence intravenous infusion of open-label study drug according to a weight-based dose regimen as early as possible post-randomisation, and within a maximum of two hours. Bedside clinical staff will transition patients to achieve sedation with the allocated α2-agonist agent as quickly as clinically feasible and safe, to replicate the way these drugs would be used in routine practice. Additional opiate will be used for analgesia using clinical judgement. Once established, additional propofol will only be used when the maximum α2-agonist dose is reached or because cardiovascular or other side-effects limit dose escalation.

  • Other names: Dexdor

Drug Clonidine

Patients will commence intravenous infusion of open-label study drug according to a weight-based dose regimen as early as possible post-randomisation, and within a maximum of two hours. Bedside clinical staff will transition patients to achieve sedation with the allocated α2-agonist agent as quickly as clinically feasible and safe, to replicate the way these drugs would be used in routine practice. Additional opiate will be used for analgesia using clinical judgement. Once established, additional propofol will only be used when the maximum α2-agonist dose is reached or because cardiovascular or other side-effects limit dose escalation.

  • Other names: Catapres

Drug Propofol

Patients will continue to receive intravenous propofol according to current usual care.

  • Other names: Diprivan

Dexmedetomidine Group Experimental

For dexmedetomidine, the regimen will follow the manufacturer's guidance and regimens used in previous trials. Dexmedetomidine will be up and down titrated against sedation targets set by clinical staff and reviewed at regular intervals, and documented at least daily. No loading dose will be administered. The starting dose will be 0.7µg.kg-1.hour-1 titrated to a maximum dose 1.4µg.kg-1 hour-1. Lower starting doses will be used at clinical discretion for patients with cardiovascular instability.

Clonidine Group Experimental

For clonidine, the regimen is designed to be equipotent with dexmedetomidine based on known pharmacokinetics and pharmacodynamics. The chosen regimen is similar to that currently used in many UK ICUs as part of routine 'off label' practice. Clonidine will be up and down titrated against sedation targets set by clinical staff and reviewed at regular intervals, and at least daily. No loading dose will be administered. The starting dose will be 1.0µg.kg-1.hour-1 titrated to a maximum dose of 2µg.kg-1.hour-1. Lower starting doses will be used at clinical discretion for patients with cardiovascular instability.

Usual Care (Propofol) Group Active Comparator

Usual Care Group : Patients will continue to receive intravenous propofol according to usual current care . The sedation targets, weaning, and sedation discontinuation procedures will follow the same clinical targets as for the clonidine and dexmedetomidine groups.

Criteria

Inclusion Criteria:

Patient requiring mechanical ventilation (MV) in an ICU
Aged 18 or over
Within 48 hours of first episode of mechanical ventilation in ICU
Requiring sedation with propofol
Expected to require a total of 48 hours of MV or more in ICU
Expected to require a further 24 hours of MV or more at the time of randomisation in the opinion of the responsible clinician

Exclusion Criteria:

Acute brain injury (traumatic brain injury; intracranial haemorrhage; ischaemic brain injury from stroke or hypoperfusion)
Post-cardiac arrest (where there is clinical concern about hypoxic brain injury)
Status epilepticus
Continuous therapeutic neuromuscular paralysis at the time of screening or randomisation
Guillain-Barre Syndrome
Myasthenia gravis
Home ventilation
Fulminant hepatic failure
Patient not expected to survive 24 hours by responsible clinician
Decision to provide only palliative or end-of-life care
Pregnancy
Known allergy to one of the study drugs
Untreated second or third degree heart block
Transferred from another Intensive Care Unit in which MV occurred for >6 hours
Prisoners
Enrolled on another CTIMP
Previously enrolled on the A2B Trial
Patient known to have experienced a period with heart rate <50 beats per minute for 60 minutes or longer since commencing mechanical ventilation in the ICU
No Results Posted