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. 2019 Nov 27;2019(11):CD012631. doi: 10.1002/14651858.CD012631.pub2

Jakkula 2018.

Methods RCT with a 2‐by‐3 factorial design. We only extracted data from the normoxia and moderate‐hyperoxia groups.
Participants Sample size: 123 (experimental 60, control 63)
Sex (male %): experimental 48%, control 50%
Age: experimental 60, control 59
Country: Finland
Setting: adults admitted to the ICU after OHCA
Disease severity score: APACHE II score median 28
Inclusion criteria

  1. Adults resuscitated from witnessed OHCA with VF or VT as the initial rhythm. In addition, all of the following inclusion criteria had to be met:

    1. ROSC 10 to 45 minutes from the onset of cardiac arrest;

    2. confirmed or suspected cardiac origin of the arrest;

    3. mechanical ventilation upon ICU arrival;

    4. markedly impaired level of consciousness defined as no response to verbal commands and GCS motor score < 5 (withdrawal to painful stimuli at best);

    5. deferred consent from next of kin possible or likely; and

    6. active intensive care and TTM initiated.


Exclusion criteria

  1. Adults with confirmed or suspected acute or pre‐existing intracranial pathology or suspicion of increased intracranial pressure, or both

  2. Adults with severe oxygenation failure defined as PaO2/FiO2 < 100 mmHg upon arrival to ICU and no improvement in oxygenation after adding sufficient PEEP level

  3. Severe COPD

  4. Age < 18 or > 80 years

  5. Pregnancy
Interventions Experimental: target PaO2of 20 to 25 kPa (150 to 187.5 mmHg). Categorized by us as using a high target in the experimental group
Control: target PaO2 of 10 to 15 kPa (75 to 112.5 mmHg) or target SpO2 of 95% to 98%. Categorized by us as using a high target in the control group
Co‐intervention: all adults received TTM at 33 °C or 36 °C and were sedated according to the treating clinicians’ instructions. All adults received standard care, monitoring and assessments based on the protocol of the ICU, including direct blood pressure monitoring via an arterial catheter.
Duration: 36 hours
Outcomes Primary outcome

  1. NSE serum concentration at 48 hours after cardiac arrest


Secondary outcomes

  1. NSE serum concentration at 24 and 72 hours after cardiac arrest

  2. S100 protein serum concentration at 24, 48, and 72 hours after cardiac arrest

  3. TnT concentration at 24, 48, and 72 hours after cardiac arrest

  4. Results of NIRS monitoring during the first 48 hours after admission to the ICU

  5. Results of continuous EEG monitoring for 48 hours after arrival at the ICU and a statement of the findings by an experienced senior neurologist or neurophysiologist

  6. CPC at 6 months after cardiac arrest

  7. Total duration of intensive care

  8. Total duration of mechanical ventilation

  9. Length of hospital stay

  10. Discharge destination

  11. Vital status at hospital discharge (dead or alive)


Feasibility outcomes

  1. Difference in PaCO2 between groups targeting low to normal (4.5 to 4.7 kPa) and high to normal (5.8 to 6.0 kPa) PaCO2

  2. Difference in PaO2 between groups targeting low to normal (10 to 15 kPa) and high to normal (20 to 25 kPa) PaO2

  3. Difference in MAP between groups targeting low to normal (65 to 75 mmHg) and high to normal (80 to 100 mmHg) MAP

  4. Distribution of values for primary and secondary outcomes

  5. Randomized or screened participant ratio

  6. Consent rate

  7. Data completion rate

  8. Recruitment duration
Notes Email sent 6 December 2018 to Dr Jakkula but no reply was received.
The trial was funded by public and private funds. The funding bodies had no input regarding the design, management, or reporting of the trial.
Risk of bias
Bias Authors' judgement Support for judgement
Random sequence generation (selection bias) Low risk Computer‐generated random numbers
Allocation concealment (selection bias) Low risk Web‐based system
Blinding of participants and personnel (performance bias) 
 All outcomes High risk The treating personnel were not blinded to treatment targets.
Blinding of outcome assessment (detection bias) 
 All outcomes Low risk The neurophysiologist analysing the EEG results and the neurologist evaluating the neurologic recovery of the participants were blinded to the study group allocations.
Incomplete outcome data (attrition bias) 
 All outcomes Low risk Less than 5% were lost to follow‐up.
Selective reporting (reporting bias) Low risk The trial was registered prior to randomization (NCT02698917).
Other bias Low risk The trial appeared to be free of other issues that could put it at risk of bias.