Alpha 2 Agonists for Sedation to Produce Better Outcomes From Critical Illness (A2B Trial)

Summary

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.

Timeline

Start

2018-12-10

Primary completion

2023-12-14

Completion

2024-07-31

Publications

• Emerson LM, Blackwood B, Kydonaki K, McKenzie C, Walsh TS, Aitken LM. The experiences of bedside nurses delivering an intensive care sedation study: A process evaluation within the A2B trial. J Intensive Care Soc. 2025 Nov 6;27(2):145-154. doi: 10.1177/17511437251381951. eCollection 2026 May.
• Walsh TS, Parker RA, Aitken LM, McKenzie CA, Emerson L, Boyd J, Macdonald A, Beveridge G, Giddings A, Hope D, Irvine S, Tuck S, Lone NI, Kydonaki K, Norrie J, Brealey D, Antcliffe D, Reay M, Williams A, Bewley J, Creagh-Brown B, McAuley DF, Dark P, Wise MP, Gordon AC, Perkins GD, Reade MC, Blackwood B, MacLullich A, Glen R, Page VJ, Weir CJ; A2B Trial Investigators. Dexmedetomidine- or Clonidine-Based Sedation Compared With Propofol in Critically Ill Patients: The A2B Randomized Clinical Trial. JAMA. 2025 Jul 1;334(1):32-45. doi: 10.1001/jama.2025.7200.
• Aitken LM, Emerson LM, Kydonaki K, Blackwood B, Creagh-Brown B, Lone NI, McKenzie CA, Reade MC, Weir CJ, Wise MP, Walsh TS. Alpha 2 agonists for sedation to produce better outcomes from critical illness (A2B trial): protocol for a mixed-methods process evaluation of a randomised controlled trial. BMJ Open. 2024 Apr 5;14(4):e081637. doi: 10.1136/bmjopen-2023-081637.
• Walsh TS, Aitken LM, McKenzie CA, Boyd J, Macdonald A, Giddings A, Hope D, Norrie J, Weir C, Parker RA, Lone NI, Emerson L, Kydonaki K, Creagh-Brown B, Morris S, McAuley DF, Dark P, Wise MP, Gordon AC, Perkins G, Reade M, Blackwood B, MacLullich A, Glen R, Page VJ. Alpha 2 agonists for sedation to produce better outcomes from critical illness (A2B Trial): protocol for a multicentre phase 3 pragmatic clinical and cost-effectiveness randomised trial in the UK. BMJ Open. 2023 Dec 10;13(12):e078645. doi: 10.1136/bmjopen-2023-078645.

Drugs

Indications

No indication recorded.