Carbogen for status epilepticus in children trial

Seizure control via pH manipulation: a phase II double blind RCT of inhaled carbogen as adjunctive treatment of paediatric convulsive status epilepticus.

Status

Recruiting

Phases

Phase 2

Study type

Interventional

Source

ISRCTN

Registry ID

ISRCTN52731862

Enrollment

424

Registered

2022-07-27

Start date

2022-11-01

Completion date

Unknown

Last updated

2026-07-20

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Severe epileptic seizures in children that are not stopping by themselves and require emergency medication to stop them Nervous System Diseases Convulsive status epilepticus in children

Interventions

Carbogen Arm (Intervention) Drug Name/Active Ingredient: Carbogen®

5% CO2: 95% O2 Formulation: Medical Gas Dose: 150 Litres Dose Frequency: Once Route of Administration: Oral Inhalation via standard hospital issued non-rebreather mask. Duration of Treatment: 10 minut

seizure recurrence within 24-hours. 30-day mortality will be recorded as an outcome measure with serious adverse events and reactions recorded from randomisation up to 30-days post-randomisation, with

Eligibility

Sex/Gender

All

Inclusion criteria

Inclusion criteria: 1. Presenting to Paediatric Emergency Department (ED) of a participating site 2. Exhibiting signs of Convulsive Status Epilepticus (CSE) (i.e. ongoing generalised tonic-clonic, generalised clonic or focal clonic convulsive seizure activity) requiring – in the view of the treating physician - emergency treatment either according to standard APLS guidelines or the child’s personalised rescue care plan in order to try and terminate the presenting seizure

Exclusion criteria

Exclusion criteria: 1. Known to have been previously enrolled in CRESCENT 2. Infantile spasms (West Syndrome) 3. Non-epileptic seizure (“pseudo status epilepticus”) 4. Tonic posturing due to suspected brain herniation 5. Has received phenytoin, levetiracetam, phenobarbital or valproate as part of the management of this episode of status epilepticus

Design outcomes

Primary

Measure	Time frame
Current primary outcome as of 10/04/2026: Success of first-line treatment of Chronic Status Epilepticus (CSE) (defined as the seizure terminating without requiring the use of any of intravenous phenytoin, phenobarbital, valproate, or Rapid Sequence Induction (RSI). Previous primary outcome: Success of first-line treatment for presenting Chronic Status Epilepticus (CSE) (i.e. child did not need to receive second-line or rescue therapy as defined within the Acute Paediatric Life Support (APLS) guidelines or their personal treatment plan). Success of first-line treatment for the presenting seizure is defined as not requiring intravenous phenytoin, phenobarbital, valproate, levetiracetam or Rapid Sequence Induction (RSI). Data for the 24hr period post-commencement of the intervention is captured on the Case Report Form (CRF) and completed following medical notes review.	—

Measure

Time frame

Current primary outcome as of 10/04/2026: Success of first-line treatment of Chronic Status Epilepticus (CSE) (defined as the seizure terminating without requiring the use of any of intravenous phenytoin, phenobarbital, valproate, or Rapid Sequence Induction (RSI). Previous primary outcome: Success of first-line treatment for presenting Chronic Status Epilepticus (CSE) (i.e. child did not need to receive second-line or rescue therapy as defined within the Acute Paediatric Life Support (APLS) guidelines or their personal treatment plan). Success of first-line treatment for the presenting seizure is defined as not requiring intravenous phenytoin, phenobarbital, valproate, levetiracetam or Rapid Sequence Induction (RSI). Data for the 24hr period post-commencement of the intervention is captured on the Case Report Form (CRF) and completed following medical notes review.

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Secondary

Measure	Time frame
1. Seizure activity visible at 5 minutes and 15 minutes post-commencement of inhalation captured on the Case Report Form (CRF). 2. Need for rapid sequence induction (RSI) with thiopentone or another agent (e.g. propofol) due to ongoing Chronic Status Epilepticus (CSE) observed in the 24-hours post-commencement of inhalation and captured on the CRF following medical notes review. 3. Need to be admitted to critical care (PICU) or high dependency unit observed in the 24-hours post-commencement of inhalation and captured on the CRF following medical notes review. 4. Seizure recurrence observed in the 24-hours post-commencement of inhalation and captured on the CRF following medical notes review. 5. Serious adverse events and reactions up to 30 days, with an onset within 24-hours of inhalation, captured on the CRF. 6. 30-day mortality post-randomisation captured on the CRF.	—

Measure

Time frame

1. Seizure activity visible at 5 minutes and 15 minutes post-commencement of inhalation captured on the Case Report Form (CRF). 2. Need for rapid sequence induction (RSI) with thiopentone or another agent (e.g. propofol) due to ongoing Chronic Status Epilepticus (CSE) observed in the 24-hours post-commencement of inhalation and captured on the CRF following medical notes review. 3. Need to be admitted to critical care (PICU) or high dependency unit observed in the 24-hours post-commencement of inhalation and captured on the CRF following medical notes review. 4. Seizure recurrence observed in the 24-hours post-commencement of inhalation and captured on the CRF following medical notes review. 5. Serious adverse events and reactions up to 30 days, with an onset within 24-hours of inhalation, captured on the CRF. 6. 30-day mortality post-randomisation captured on the CRF.

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Countries

England, United Kingdom

Contacts

Public ContactCRESCENT Trial Team

crescent-trial@liverpool.ac.uk-

Outcome results

None listed

Source: ISRCTN (via WHO ICTRP) · Data processed: Jul 23, 2026