ACLS - Post-Cardiac Arrest Care
Summary
- Oxygen Targets: 98-100% initially, and then PaO2 68-105 mmHg (broad range).
- Blood Pressure Targets: Normal targets (>63-65 mmHg).
- Temperature: Avoid hyperthermia/fever.
Post-Arrest Oxygen Targets
Several trials have been done in this space:
- BOX (2022): For survivors of OHCA admitted to the ICU, there were no differences between restrictive (PaO2 68 to 75 mmHg, initial FiO2 0.3) or liberal (98 to 105 mmHg, initial FiO2 0.6) oxygenation strategies. Minimum target SpO2 >= 93%.
- Neurologic outcomes
- 90-day mortality
- EXACT (2022): For survivors of OHCA who achieve ROSC in the field, restrictive (SpO2 90-94%) was not better than liberal (SpO2 98-100%) oxygen targets with regards to survival to hospital discharge. However, the restrictive arm had lower survival (38 vs 48%, p=0.05) and more hypoxic episores (31 vs 16%)
Conclusion: in OHCA, liberal post-ROSC resuscitation targets are reasonable. No evidence for IHCA. Consider SpO2 > 98% early on, or PaO2 68-105 mmHg once admitted to the ICU.
Post-Arrest Blood Pressure Targets
- Usual hemodynamic targets may be utilized (e.g., often aiming for MAP >65 mm).
- The BOX Trial (2022) demonstrated that targeting a higher MAP did not improve neurological outcomes.
Post-Arrest Targeted Temperature Management
Rationale
Risks of Shivering - lactic acidosis - elevated ICP - Rhabdomyolysis - discomfort
Risks of Hypothermic TTM - hemodynamic instability - TdP - Increased paralysis, prolonged ventilation - Delayed awakening
Hypothermic TTM
- This concept was based on two 2002 NEJM studies (HACA, Bernard) that suggested a 14% mortality ARR.
- TTM Trial (2013) showed no difference between TTM33 and TTM36 with regards to survival and neurologic outcome.
- EUROTHERM3235 Trial (2015) showed that in patients with TBI, hypothermia (32-35 Celsius) led to worse neurological outcomes and increased mortality.
- POLAR Trial (2018) showed that in patients with severe blunt TBI, hypothermia (target 35 --> 33 Celsius) was associated with increased mortality, increased pneumonia, increased bradycardia, and increased time on the ventilator.
- HYPERION Trial (2019) showed a small improvement (survival with favourable neuro-status) from 24 hours of hypothermia (33 Celcius) vs normothermia (36.5-37.5 Celcius) among patients with cardiac arrest from a nonshockable rhythm (10% vs. 6% with good neurological outcome, p=0.047)
| Indication | Recommendations (as of 2020) |
|---|---|
| Cardiac arrest | Consider active TTM, target 33-36 deg Celcius. |
| TBI | Do not do TTM. |
Normothermic TTM
The TTM2 Trial (2021) showed that in out-of-hospital cardiac arrest survivors who remain comatose, hypothermia is not better than normothermia (i.e. prevention of fever) with regards to long-term mortality or functional status. Therefore, do not routinely use this in the care of surviving OHCA patients. - maintain <= 37.5°C, treated only if temp >= 37.8°C - time period: up to 40-72 hours post-intervention
| Indication | Recommendations (as of 2022) |
|---|---|
| All | Target avoidance of fever (<37.8) |
Achieving Normothermic TTM
- routine Tylenol for everyone
- If febrile, then: external adaptive cooling device (targe 37.5), buspirone 30 mg per tube q8-12hr scheduled, Mg replacement
- If still shivering: warm the hands and feet, dexmedetomidine +/- PPF +/- ketamine, target Mg 1.2-1.6 mM, Zofran scheduled
- If still shivering: fentanyl boluses, paralysis