Co-enrolment is permitted with all observational studies, including those collecting samples.

We have co-enrolment agreements in place for the following trials:

We are happy for co-enrolment with the following trials, but we are not yet aware of the other trial team's decision on co-enrolment:


Q: When are the recruitment start and end dates?
A: 12/04/2022 to 30/06/2024

Q: When is the overall study end/closing date?
A: 31/12/2025

Q: Can we have the SIV slides?
A: The slides are available here.

Q: Who is responsible for sending out the follow-up questionnaires to patients?
A: ICNARC CTU will send the questionnaires to patients. The only exception would be where the patient is still in your hospital at 90 days, in which case we may get in touch with your team to see if you are able to approach the patient in person.


Q: Who can confirm eligibility?
A: A doctor, medical practitioner or nurse can confirm eligibility, as long as they are appropriately qualified, have undergone study training documented on the Training Log and are signed off on the Delegation Log for this task by the PI. There must still be overall oversight by a medically qualified doctor.

Q: Are any level 2 or level 3 patients to be included in screening (as we have a mixed level critical care), or only level 3 as 'ICU' patients?
A: Yes, level 2 and level 3 patients should be included in screening.

Q: Is there a specified time limit between meeting eligibility and randomisation?

A: No, but sites are encouraged to randomise ASAP once eligibility has been confirmed. Patients should meet all inclusion criteria and no exclusion criteria at the point of randomisation.

Q: If a patient has high ketones not caused by diabetes, would this patient be eligible?
A: Yes, this patient would be eligible if they met all inclusion criteria and no exclusion criteria. 

Q: Should patients who have expressed that they do not want KRT be included in the "Deemed unsuitable for KRT" exclusion?
A: Yes. If the patient is deemed unsuitable for clinical reasons or if the patient does not wish to have KRT, please tick the "Deemed unsuitable for KRT" exclusion on the screening log and add a comment detailing whether it was clinician’s decision or the patient’s decision.


Q: Who can randomise?
A: Staff members signed off on the Training and Delegation Logs for this task can randomise. Trial training includes reading the current approved protocol and relevant trial-specific SOPs, and either attending a live SIV or watching the relevant portions of the recording (which is available here). GCP training is not required.

Q: Is a hard copy of the Randomisation Form required?
A: Yes, a hard copy of the Randomisation Form must be completed and signed off for each patient at the point of randomisation. It should then be stored in the ISF.

Q: Is there a specified time limit between randomisation and first dose of sodium bicarbonate?
A: No, but the first dose of sodium bicarbonate should be given ASAP after randomisation.

Q: What if a patient has received sodium bicarbonate prior to randomisation?
A: If they still meet eligibility criteria at the time of randomisation, then they can be randomised into the trial. Please record the volume of sodium bicarbonate received in the 24 hours prior to randomisation on MACRO.



Q: What brand of sodium bicarbonate 8.4% w/v can be used?
A: Any brand with marketing authorisation in the UK may be used in the trial.

Q: Is trial-specific labelling required?
A: No. 

Q: Is a trial-specific prescription required?
A: No, but sodium bicarbonate 8.4% w/v should be dispensed in accordance with a prescription as per routine clinical practice at your site. The investigators recommend that this can be written as 'prn up to a max daily dose of 500ml/24 hours.'

Q: Do prescribers need to be GCP trained if they are only going to prescribe?
A: If prescribing is part of their job, they will not require GCP training. However, they will need to be signed off on the Training Log as having read the current approved protocol and relevant trial-specific SOPs, and either attended a live SIV or watched the relevant portions of the recording (which is available here

Q: Is sodium bicarbonate 8.4% w/v given centrally or peripherally?
A: Ultimately this depends on your Trust guidelines but the investigators agree sodium bicarbonate 8.4% w/v would usually be given centrally, though a dose in an emergency could initially be delivered peripherally.

If the patient is otherwise eligible but does not have a central line and no plans for one for their care, then record this patient as ‘Eligible not randomised’ and document the reason on the screening and enrolment log 

Q: What happens if a patient is discharged and readmitted to ICU?
A: The intervention period begins immediately following randomisation and should continue until discharge from critical care, initiation of KRT or 90 days, whichever comes first. If a patient is discharged and readmitted to ICU, treatment will be at the discretion of clinical staff.

Q: Post-randomisation, if pH<7.30 due to respiratory acidosis subsequently ie several days later, is that an exclusion to giving sodium bicarbonate?
A: If the respiratory acidosis is causing the low pH then yes, this would be an acceptable reason for not giving sodium bicarbonate to a participant in the intervention group – this should be recorded on the Sodium bicarbonate administration deviation form on MACRO.

Q: In the intervention flow, if pH≥7.30 we should monitor pH for duration of critical care stay. If a patient is on ICU for several weeks, we often remove their arterial lines during convalescence – is a venous gas okay?
A: Yes, a venous gas is acceptable. Blood gas values are collected:
  • 6-hourly from Day 1 (from time of randomisation) to Day 5
  • Daily from Day 6+ (record values from the first blood gas after the standard unit charting time) 


Q: Who can approach for consent?
A: Staff members who have been signed off on the Training and Delegation Logs and are trained in GCP can approach for consent. This can include doctors, nurses, other allied health professionals and research/clinical trial practitioners. The PI retains overall responsibility for the informed consent of participants at their site and must ensure that any person delegated this responsibility is adequately trained.

Q: Does the Personal Legal Representative need to be the next of kin?
A: No – the Personal Legal Representative can be a relative or close friend of the patient.

Q: Can the Professional Legal Representative be involved in the patient's care?
A: Yes, but the Professional Legal Representative must not be on the Delegation Log or Training Log for the trial.

Q: Does the witness for the telephone calls need to be GCP trained or on the Delegation Log?
A: No.



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