Answers to Frequently Asked Questions (FAQs) can be found here.


12/04/2022 to 30/06/2024


The slides are available here.

ICNARC clinical trials unit (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


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

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

  • A-STOP
  • ADAPT-Sepsis
  • iREHAB
  • T4P
  • UK-ROX

Please email mosaicc@icnarc.org with any questions about co-enrolment


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. This means the doctor in charge of the patient must be aware of the MOSAICC trial and agree that the patient can be recruited. This should be documented in the patient’s medical records

No. Patients must be admitted to the critical care unit in order to be eligible. Patients can be screened prior to admission so that they can be recruited as soon as they are admitted to the critical care unit. Remember to confirm that the patient meets eligibility at the time of randomisation

Yes, level 2 and level 3 patients should be included in screening

This is defined as high output from the stoma thought to be the predominant cause of the acidosis. The presence of a stoma per se does not exclude potentially eligible participants

This exclusion should only be applied to patients where there is an immediate indication for KRT which cannot be delayed (suggested criteria in section 4.5.3 of the protocol). Otherwise, enrolment into the trial should be considered

The intention of this criterion is to exclude patients with pre-existing kidney failure, defined as documented eGFR<15 ml/min/1.73m2 prior to the current acute illness or those on long-term (chronic) dialysis.

However, confusion has arisen as some patients have been incorrectly excluded because of a low eGFR result taken during this hospitalisation at the time of AKI. It is expected that eGFR will be low at the time of AKI and some patients will have ICU blood tests with eGFR results <15 ml/min/1.73m2, but this does not exclude the patient from participation.

To summarise – when looking at eligibility criteria, review eGFR results from before the current acute illness.

  • If there are multiple results available, use the one closest in date, but prior, to onset of the current acute illness. If there are no prior documented results, assume eGFR is ≥15 ml/min/1.73m2

If a patient with no pre-hospitalisation creatinine values (within 365 days) is admitted to the hospital with a suspected AKI, any creatinine values from that admission are unlikely to be baseline values. Consequently the patient will not meet the inclusion criteria for MOSAICC. Therefore, if the clinical interpretation is that the patient was admitted to hospital  with AKI and there are no pre-hospitalisation values then do not use the current admission values but use the calculator to calculate the patient’s baseline.


However, if the patient has been on the ward and then develops an AKI and is transferred to ICU, that’s when using the lowest creatinine value from the hospital admission would be appropriate

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

Yes, this patient would be eligible if they met all inclusion criteria and no exclusion criteria

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

The trial requires ABG measurements for confirmation of eligibility and administration of the protocol. This could be an arterial stab at first, however insertion of an arterial line is required (and is likely in this patient population).


We recognise that arterial lines may be removed or become displaced, and the clinical decision may be that the patient does not need re-insertion of an arterial line (for example if they have been in ICU a while and are clinical improving / waiting for a ward bed). In this case, record VBGs on the CRF and make a comment against each measurement that the value is from VBG and not an ABG.

Note – that if the patient is randomised to the bicarbonate arm, and the pH falls below 7.3 at any time (ABG value) then ABG values are required for administration of the protocol

It is difficult to assess whether a patient is symptomatic when intubated and ventilated. If the hypocalcaemia was found incidentally, the patient is not being treated clinically for hypocalcaemia, and the treating clinician would be happy to administer sodium bicarbonate then they do not meet this exclusion criteria

If the DKA is corrected and patient meets the inclusion criteria and no exclusion criteria at the time of screening then yes, they can be randomised


Staff members signed off on the Training and Delegation Logs for this task can randomise. GCP training is not required.

They must be appropriately trained which involves reading the eligibility and randomisation short slide set or attending an online eligibility/screening training session run by ICNARC. The staff member may also wish to watch relevant sections of the SIV which can be found on the website

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

No, but the first dose of sodium bicarbonate should be given ASAP after randomisation

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

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

Once randomised the patient should stay in the trial, data collection and consent procedures should be continued as per protocol. If randomised to the sodium bicarbonate arm and local policy does not allow administration of sodium bicarbonate w/c 8.4% via peripheral IV access, then please complete the protocol deviation form on macro with the reason explained in the comments box. This will need to be completed every time the patient should have received sodium bicarbonate


Any brand with marketing authorisation in the UK may be used in the trial


No, but sodium bicarbonate 8.4% w/v should be prescribed and dispensed 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.’

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 relevant sections of the current approved protocol and relevant trial-specific SOPs. The staff member may wish to watch relevant sections of the SIV which can be found on the website

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

Control group: No IV bicarbonate should be administered but if the patient is regularly on any other medication including oral bicarbonate and would usually restart then this is fine

Intervention group: Patients randomised to the intervention group should not start on additional bicarbonate outside of the trial but if they were already regularly on oral bicarbonate then this can be given at clinician discretion (provided there would not be any safety concern with receiving both oral and IV bicarb)

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

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

Yes, a venous gas is acceptable if there is no arterial line. 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)

Please add a comment against the pH on MACRO if the blood gas is venous


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

No – the Personal Legal Representative can be a relative or close friend of the patient

Yes, but the Professional Legal Representative must not be on the Delegation Log or Training Log for the trial

Yes. The witness must be a person who is independent of the trial, who cannot be unfairly influenced by people involved in the trial. Therefore they should not be on the delegation or training log

If the hospital the patient is transferred to is not taking part in MOSAICC and appropriate legal representative consent has been obtained, then patient consent does not need to be obtained. However it would be good practice to keep in contact with the hospital they have been transferred to and inform the patient of their involvement in the trial following discharge, when/ if they regain capacity.

If the patient has been transferred to a hospital that is taking part in MOSAICC then patient consent should be obtained, by the receiving site,  if they regain capacity prior to hospital discharge. If unsure whether the hospital is part in the MOSAICC trial, then please contact the trial management team and we will be able to assist