Recent years have seen a paradigm shift in cardiac arrest from the traditional mantra of airway, breathing circulation (ABC’s) to circulation, airway, breathing (CAB). This change represents the understanding that circulation is of paramount importance and thus, advanced airway management has been de-emphasized. This change is rational as the only interventions that have been shown to be beneficial in cardiac arrest are high-quality CPR and defibrillation. Both of these measures improve coronary artery perfusion and cerebral perfusion pressure which improves oxygen delivery to the body as opposed to airway interventions which simply improve oxygenation of the lungs. Improving oxygen delivery to the heart makes successful defibrillation more likely and improved oxygen delivery to the brain improves the chance of a good neurologic outcome. The decreased role for advanced airways has not been well studied in in-hospital cardiac arrests.
Is early intubation (within the first 15 minutes) in patients with cardiac arrest associated with improved outcomes.
Patients >/= 18 years of age with an in-hospital cardiac arrest in which chest compressions were delivered.
Intubation in the first 15 minutes of arrest management
No Intubation in the first 15 minutes of arrest management
Primary: Survival to hospital discharge
Secondary: Return of spontaneous circulation (ROSC), Good neurologic outcome (Cerebral Performance Category 1 or 2)
Tracheal Intubation: Insertion of a tracheal or tracheostomy tube during cardiac arrest
Time to Tracheal Intubation: The interval from loss of pulses until tracheal tube was inserted
All times in the GWTG-R are recorded as whole minutes, therefore a time of 0 minutes indicates that the tracheal intubation was performed in the same minute that the pulses were lost
Retrospective analysis of multicenter, prospectively created data
Invasive airway already in place at time of cardiac arrest (i.e. tracheal tube, tracheostomy, laryngeal mask airway, or other invasive airways not including nasopharyngeal or oropharyngeal airways)
Hospital visitors and employees
Patients missing data on tracheal intubation, covariates (except race), and survival
- Propensity matched cohort selected from > 108,000 patients from 668 hospitals
- Propensity matching took into account numerous factors including, time to intubation stratified into 0-4, 5-9 and 10-15 minutes
- Survival to discharge lower in the intubated group
- Overall survival 22.4% of patients
- Intubated: 16.3%
- Non-intubated: 19.4%
- 3.1% absolute difference, RR = 0.84 (CI 0.81-0.87)
- ROSC: lower in the intubated group
- Overall ROSC: 62.5%
- Intubated: 57.8%
- Non-intubated: 59.3%
- 1.5% absolute difference, RR = 0.97 (CI: 0.96-0.99)
- Good functional outcome: lower in the intubated group
- Overall 16%
- Intubated: 10.6%
- Non-intubated: 13.6%
- 3.0% absolute difference, RR = .78 (CI: 0.75 – 0.81)
- Lower likelihood of survival in patients with shockable rhythms who were intubated in the first 15 minutes
- Asks an important question with limited available data
- Large study with a patient centered outcome
- Used time-dependent propensity matching using pre-specified time subgroups
- Unsuccessful intubation attempts were not registered. This may affect outcomes in the intubated and non-intubated group of patients alike
- The study is not prospective or randomized and, thus, can only show an association, not causation
- It is unclear why providers chose to intubate some patients and not others
- Abstractors assessing outcomes from the chart were not blinded to exposure status
- There are a number of potential confounders including the fact that patients who were not intubated were more likely to be on a non-telemetry floor and not in the ICU.
- Epinephrine was more commonly administered in the intubation group but the benefit of epinephrine is not well established.
- Quality of compressions was not documented
- At least one variable required for this study was missing in 25% of the patients included in the study
Among adult patients with in-hospital cardiac arrest, initiationm of tracheal
intubation within any given minute during the first 15 minutes of resuscitation, compared with no intubation during that minute, was associated with decreased survival to hospital discharge. Although the study design does not eliminate the potential for confounding by indication, these findings do not support early tracheal intubation for adult in-hospital cardiac arrest.
In this retrospective analysis, intubation was associated with worse outcomes in patients with in-hospital cardiac arrest.
Potential Impact To Current Practice
This data argues against routine advanced airway placement in patients with in-hospital cardiac arrest.
In the absence of high-quality studies, providers should consider supporting oxygenation in patients with in-hospital cardiac arrest with a bag-valve mask instead of placement of an advanced airway early in management (< 15 minutes). Focus instead should be placed on high-quality compressions and defibrillation when appropriate. Perhaps, advanced airway placement can be deferred to the post-ROSC state.