Airway Management in Cardiac Arrest
- Jun 3rd, 2019
- Shyam Murali
Author: Shyam Murali, MD (@smuramed, Mercy St. Vincent Emergency Medicine Residency) // Edited by: Tim Montrief, MD (@EMinMiami), Alex Koyfman, MD (@EMHighAK), and Brit Long, MD (@long_brit)
Case: EMS wheels in a patient undergoing active compressions with a mechanical CPR device. They give you a quick report: “This is a 63-year-old female who became unresponsive just before dinner. Her son checked to see if she was breathing and began CPR immediately. On our arrival about four minutes after she collapsed, the patient was in ventricular fibrillation on the monitor. We took over CPR and shocked her immediately. She has had two shocks and one dose of epinephrine since we got to her. She has a history of COPD, diabetes, and coronary artery disease. We were right around the corner, so we decided to transport quickly. We haven’t been able to secure an airway yet and have just been bagging on the way. Any questions?”
In your head, you know this patient has a pretty good chance of survival: early chest compressions by a bystander, initial shockable rhythm, relatively young age. You start to think about your next steps…
Each year, nearly 600,000 cardiac arrests occur.1 Much of the management of cardiac arrest has been researched, and strong recommendations exist. Over the past few years, there has been a significant paradigm shift in management from A-B-C to C-A-B, placing increasing importance on minimizing interruptions during chest compressions and decreasing the time to defibrillation.2,3 Airway management during cardiac arrest is still unclear because there is a paucity of high-quality studies. Unfortunately, it is difficult to conduct a randomized clinical trial due to the emergent nature of the situation and the multitude of airway management techniques available to healthcare providers. However, we still have some data to guide us, and it is important to consider the patient factors (patient age, in- vs out-of-hospital, comorbidities, etc.) when determining the appropriate management. Providers must also keep in mind that the priorities are high quality chest compressions, with defibrillation for shockable rhythms during cardiac arrest.
The data explore a variety of outcomes: return of spontaneous circulation (ROSC), sustained ROSC, survival to hospital admission, survival to hospital discharge, and survival with good neurologic outcome. As one of the most patient centered outcomes, good neurologic function is determined by scoring systems such as the Cerebral Performance Category (CPC) or Modified Rankin Scale (mRS) (Table 1).
Table 1. Comparison of Cerebral Performance Category (CPC) and Modified Rankin Scale (mRS)
Out-of-Hospital Cardiac Arrest
Out-of-hospital cardiac arrest (OHCA) currently has the best research with a few randomized clinical trials. However, most of literature consists of retrospective analyses involving large registries, or small cohorts from one or a few sites. Some compare basic airway maneuvers to advanced airway maneuvers, while others compare endotracheal intubation (ETI) use to supraglottic airway (SGA; King LT, LMA, iGel, Combitube, etc.) use.
In general, the data demonstrate consistent support for basic airway maneuvers: bag valve mask with good seal, oropharyngeal and nasopharyngeal airways, appropriate maneuvers to minimize gastric insufflation (jaw thrust, low-pressure squeezes, etc.), and avoidance of hyperventilation.
- In a retrospective observational cohort study by Hanif et al. in southwest Los Angeles County, the investigators found that patients managed with a bag valve mask (BVM) had an odds ratio (OR) of 4.5 (95% CI 2.3–8.9) for survival to hospital discharge when compared to those managed with ETI.4
- Hasegawa et al. performed a registry study in 2013 to analyze the effect of airway management on neurologically favorable survival (CPC 1 or 2) at one month, prehospital return of spontaneous circulation (ROSC), and survival at one month.5 They found a significant negative association between any advanced airway management (ETI or SGA) and all three end-point measures (OR 0.38 [95% CI 0.36-0.39] for favorable neurologic outcome, OR 0.73 [95% CI 0.71-0.75] for one month survival, OR 0.67 for ROSC [95% CI 0.66-0.69]).
- In a study published just this year, Izawa et al. found that favorable functional survival (CPC 1 or 2) was lower in the advanced airway group if the initial rhythm was a shockable rhythm (adjusted risk ratio [aRR] of 0.87 [95% CI 0.79-0.96]).7 Conversely, they found a nonsignificant improvement in favorable functional survival in the advanced airway group with a non-shockable rhythm (aRR of 1.11 [95% CI 0.97-1.26]). This study confirmed the importance of immediate defibrillation and continuous chest compressions for patients with a shockable rhythm; the investigators posit that patients with non-shockable rhythms could benefit from delivery of oxygen with protected airway ventilation. The same team also determined that early intubation had higher functionally favorable survival at one month among patients who received advanced airway management (adjusted odds ratio [aOR] of 1.58 [95% CI 1.24–2.02 for functionally favorable survival).8 Longer time to intubation was associated with lower rates of functionally favorable survival, ROSC, hospital admission, and survival at one month.
- A secondary analysis of the Cardiac Arrest Registry to Enhance Survival (CARES) registry was performed to assess sustained ROSC (>20 minutes or arrival to ED), survival to hospital admission, survival to hospital discharge, and survival to discharge with good neurologic outcome (CPC 1 or 2).6 CARES is a multicenter registry involving over 400 EMS agencies from 40 communities and 10 state-based registries. The study determined that patients receiving no advanced airway management had better outcomes compared to ETI or SGA (no advanced airway had OR 1.31 [95% CI 1.16-1.49] for survival to hospital admission, 2.96 [95% CI 2.50-3.51] for survival to discharge, and 4.24 [95% CI 3.46-5.20] for hospital discharge with good neurologic function). Interestingly, they also noted that ETI was independently associated with increased adjusted odds of all outcomes compared to SGA (OR 1.35 [95% CI 1.19-1.54] for sustained ROSC, OR 1.36 [95% CI 1.19-1.55] for survival to admission, OR 1.41 [95% CI 1.14-1.76] for survival to discharge, OR 1.44 [95% CI 1.10-1.88] for survival to discharge with good neurologic outcome).
On the other hand, some studies show contrasting results:
- In a retrospective registry study by Chiang et al. in Taipei, investigators showed that successful intubation was associated with increased chances of sustained ROSC (aOR 1.91 [95% CI 1.55-2.19]), survival to hospital discharge (aOR 1.98 [95% CI1.57-2.49]), and favorable neurologic outcomes (CPC 1 or 2; aOR 1.44 [95% CI 1.03-2.03).9 A few interesting notes about this study:
- Approximately 18% of OHCA patients were intubated compared with less than 6% in other Asian registry studies. Taipei City paramedics have been trained and authorized to perform intubation since 2000, the earliest among metropolitan Asian areas.
- There was a lower proportion of shockable rhythms compared to the CARES network study (see results of the CARES study above). Shockable rhythms are more likely to achieve ROSC in the field with favorable neurologic outcome.
- The paramedics used a protocol that limited intubation to only a single attempt with a protocol-requested capnography check after intubation. These protocol items alone could improve outcomes by increasing focus on better quality CPR, reduced pauses in chest compressions, and quicker confirmation of correct tube placement.10
- Similarly, a secondary analysis of the Cardiovascular Disease Surveillance (CAVAS) database showed that the likelihoods of survival to discharge (aOR 1.49 [95% CI 1.178-1.885]) and neurologically favorable survival to discharge (aOR 1.405 [95% CI 1.1001-1.971]) were significantly higher in the ETI group compared to BVM group.11 In this study, SGA was associated with worse outcomes than the BVM group.
There are many practical implications of using a supraglottic airway versus endotracheal intubation. Firstly, they are significantly easier to place and have comparable ventilation to endotracheal tubes (ETT) when placed correctly.12 Training prehospital providers to use SGAs takes less time and many countries allow basic life support (BLS) providers to place these devices. Although the device itself is slightly more expensive than the ETT, it does not require extra equipment to perform placement (direct or video laryngoscopes, stylets, bougies, etc.).
However, rates of complications such as aspiration, esophageal laceration, subcutaneous emphysema, tongue edema, and pneumomediastinum are higher with SGAs (in one study, the rates of these complications with prehospital Combitube use were 17%, 3.2%, 0.7%, 0.7%, and 0.3%, respectively).13,14 ETTs, although they take longer to place and require more training, provide added security, remove the risk of gastric insufflation and emesis (if placed correctly), and have less risk of being dislodged. They may also be associated with improved “no flow ratio” (ie. better compression fraction).15 Many studies have compared the two advanced airway interventions:
- In 2012, Wang et al. performed a secondary analysis of the ROC PRIMED study to compare the use of ETI to SGA for out of hospital cardiac arrests.16 Their primary outcome was survival to hospital discharge with a mRS of 3 or less, a great, patient-oriented outcome. They found that survival with good neurologic function was statistically significantly higher with endotracheal intubation than with supraglottic airway with an odds ratio of 1.4 [95% CI 1.04-1.89]. Endotracheal intubation also increased the odds of 24-hour survival and ROSC. However, in a secondary sensitivity analysis, they found higher survival among patients not receiving any successful advanced airway (either ETT or SGA), further supporting basic airway interventions over advanced airway interventions.
We also have a couple systematic reviews and meta-analyses that look closely at the existing research to determine how to manage the airway in a cardiac arrest:
- In 2013, Fouche et al. reviewed the existing research in a systematic review/meta-analysis that compared basic vs. advanced airway interventions.20By examining 17 studies, they found that advanced airway interventions were associated with worse outcomes than basic airway interventions. They also noted that patients who underwent SGA placement did worse than patients who underwent ETI.
- Benoit et al. analyzed 10 observational studies and determined that ETI was associated with improved outcomes after OHCA compared to 14ETI was associated with higher odds of ROSC, survival to hospital admission, and hospital discharge with good neurologic function. However, they noted there was significant study-level heterogeneity with “low” or “very low” quality of evidence for all studies.
While they are useful at putting together and summarizing the existing literature, systematic reviews and meta-analyses are plagued by significant heterogeneity of the studies and must therefore be evaluated carefully.
The best evidence we have that addresses this topic are a few well-designed randomized trials that address the BVM vs. ETI vs. SGA debate:
- Jabre et al. enrolled 2043 patients in a randomized, multicenter, non-inferiority study in France and Belgium, comparing BVM to ETI for initial airway management of OHCA. In their intention-to-treat analysis, survival with good neurologic function (CPC 1 or 2) at 28 days was 4.3% in the BVM group and 4.2% in the ETI group (difference, 0.11% [1-sided 97.5% CI, −1.64% to infinity]). The investigators failed to demonstrate that one technique was worse than the other with respect to this primary outcome. However, they discovered that adverse events (airway management difficulties, failure, and regurgitation) occurred more frequently in the BVM group. This study included physicians in their prehospital system and limits its generalizability to the United States.
- In 2018, Wang et al. performed a multicenter cluster-crossover randomized trial that involved 27 EMS agencies associated with sites of the Resuscitation Outcomes Consortium (“PART” trial).17 The EMS agencies were randomized to either ETI or King Laryngeal Tube (LT) and then crossed over during the study. They found that there was a modestly better 72-hour survival in the LT group that was statistically significant. However, after post hoc adjustment for patient characteristics and randomization, the 72-hour survival difference was no longer statistically significant (adjusted difference of 2.1% [95% CI -0.5%-4.8%]). In this study, initial ETI success rate was very low (33%) compared to a previously reported rate (91%) in a meta-analysis, limiting its generalizability.
- Benger et al. also performed a multicenter cluster randomized clinical trial in which they assessed neurologic function at hospital discharge or at 30 days (whichever occurred sooner).18 Investigators randomized paramedics in England to either the ETI or SGA (i-Gel) group and found no significant difference in good neurologic function (adjusted risk difference -0.6 [95% CI -1.6%-0.4%]). In subsequent analyses, they found some slight but significant improvement in outcomes in the SGA group (OR 1.57 [95% CI 1.18-2.07]). Check out this great Rebel EM review for an in-depth analysis of this study. You can also read this Editorial by Anderson and Granfeldt for a discussion about these last two articles by Wang and Benger.19
Based on the above research, it seems that basic airway interventions, such as jaw maneuvers, airway adjuncts (OPA/NPA), and bag valve masks, are associated with better outcomes than advanced airway interventions (SGA, ETI) in OHCA. At this time, it is still unclear whether an ED physician with more training in airway management would have improved outcomes after intubation compared to a paramedic who performs fewer intubations each year on average, has the increased stresses of an uncontrolled environment, and is frequently working in very small groups. Based on the existing research, when your next cardiac arrest comes in, it seems best to focus your airway efforts on those basic maneuvers; if you choose to use an advanced airway, use what you are most comfortable with. Transport time should also be taken into consideration, as an SGA may be much easier to use for prolonged transports.
In-Hospital Cardiac Arrest
As ER physicians, we usually manage the cardiac arrests that occur in the field. However, many ER physicians in the US staff the entire hospital overnight and must manage arrests that take place within the hospital. Here is what the current literature shows:
- Anderson et al. performed a retrospective analysis of the Get With the Guidelines – Resuscitation registry.21 They found that ETI was more strongly associated with lower likelihood of survival in those with an initial shockable rhythm compared with those who had an initial nonshockable rhythm (RR of 0.68 [95% CI 0.65-0.72]). Interestingly, they noted that in patients without preexisting respiratory insufficiency, intubation was associated with a lower likelihood of survival (RR of 0.78 [95% CI 0.75-0.81]), while there was no association in patients with preexisting respiratory insufficiency. Patients who were in an initial shockable rhythm or had no preexisting respiratory insufficiency did worse if they were intubated. Also, patients intubated within the first 15 minutes had lower survival compared to those who were intubated after the first 15 minutes (RR of 0.75 [95% CI 0.73-0.76]). In a sensitivity analysis, they concluded that tracheal intubation was associated with lower likelihood of positive outcomes (adjusted RR 0.97 [95% CI 0.97-0.98] for ROSC, 0.84 [95% CI 0.81-0.87] for survival to hospital discharge, 0.81 [95% CI 0.79-0.84] for favorable functional outcome with CPC 1 or 2).
- In 2012, Yamada et al. conducted a retrospective review of 105 IHCA over a span of 6 years at a single hospital.22 In their study, BVM use WITH airway adjuncts had an odds ratio of 3.52 (95% CI 1.07-11.5)for good neurological recovery (CPC 1); conversely, ETI had an odds ratio of 0.32 (95% CI 0.12-0.84). Both findings were statistically significant, and the effect persisted when they were adjusted for age and sex.
Unfortunately, we do not have enough studies on the inpatient side of this discussion. Potential reasons for why early ETI might have worsened outcomes include prolonged interruptions of chest compressions, hyperventilation and hyperoxia, delay in other interventions such as defibrillation, and unrecognized esophageal intubation.23 Using what research we do have and considering practical aspects of care, it seems prudent to delay intubation until the most important parts of cardiac arrest management are taken care of or are in process: high-quality chest compressions and early defibrillation, if needed.
Pediatric Cardiac Arrest
The proportion of respiratory causes of arrest is higher in the pediatric population than in adults. As such, it seems intuitive that our pediatric patients would benefit from intubation, but the evidence seems to show the opposite:
- An analysis of the Get With the Guidelines – Resuscitation registry showed that ETI was associated with decreased ROSC (RR 0.84 [95% CI .081-.088]) and worse neurologic outcomes at discharge (RR 0.55 [95% CI 0.48-0.63]).24 A time-dependent propensity score-matched cohort showed that survival to hospital discharge was lower in the ETI group (RR 0.89 [95% CI 0.81-0.99]) and there was no significant difference in ROSC or favorable neurologic outcome. A sensitivity analysis showed that ETI was associated with worse outcomes (decreased survival to discharge RR 0.88 [95% CI 0.79-0.99], decreased favorable neurologic outcome RR 0.85 [95% CI 0.73-0.98]).
- Gupta et al. performed a singly-center retrospective review of medical records from pediatric cardiac arrests that took place in the NICU, PICU, or peds CVICU.25 They found that the presence of an invasive airway before cardiac arrest (OR 0.7 [95% CI 0.42-1.16] for survival to discharge; OR 0.6 [95% CI 0.34-1.05] for good neurologic outcomes) or early placement of one during cardiac arrest (OR 1.05 [95% CI 0.78-1.42] for survival to discharge; OR 1.08 [95% CI 0.77-1.53] for good neurologic outcomes) was not associated with an improvement in survival to discharge or good neurological outcomes. In this study, patients who were already intubated were sicker and had higher rates of hypotension, pulmonary edema, and multiorgan failure.
- A retrospective analysis of the CARES database showed that BVM was associated with higher survival to hospital discharge compared to ETI and SGA (OR 0.39 [95% CI 0.26-0.59] for survival to hospital discharge for ETI compared to BVM; OR 0.32 [95% CI 0.12-0.84] for SGA compared to BVM).26 Although the advanced airway techniques had a nonsignificant increased likelihood of sustained ROSC, they did not improve Pediatric CPC score or survival to discharge.
When a pediatric cardiac arrest comes into or occurs in your department, focus on basic airway interventions in addition to high-quality compressions and defibrillation.
Challenges in studying this topic
There are several difficulties that prevent us from performing high quality randomized controlled trials. Firstly, the urgency of interventions makes it hard to perform a patient-level randomization. Due to the relative infrequency of the event, prospective trials would require coordination across numerous sites to have a large enough sample size to show effects. Observational studies are at risk for various biases including resuscitation time bias (patients undergoing longer resuscitation are more likely to be intubated), confounding by indication (an intervention is indicated by a perceived high risk or poor prognosis; ie. patients who look sick, or dead, got an ETT), and others. In these studies, it is important to address patient-oriented outcomes; survival with good neurologic function is probably the best outcome to evaluate in such studies. Finally, once the patient arrives to the emergency department, about 65% of EMS SGAs are converted to an endotracheal tube and about 33% are reintubated.11 This could possibly alter outcomes in our research.
While this is certainly a difficult area to research, there is a randomized controlled trial currently being conducted to compare ETI and SGA. Hopefully, the study will give us more clarity on airway management during cardiac arrest.
- There is a lack of high-quality evidence and significant difficulty in conducting a randomized controlled trial to determine the best strategy for airway management in cardiac arrest.
- STICK TO THE BASICS: Intubation should have a lower priority compared to high-quality chest compressions and early defibrillation when needed. Remember to consider your reversible causes and treat appropriately.
- For cardiac arrests both inside and outside the hospital, there is moderate-quality evidence that supports basic airway interventions (BVM, maneuvers to minimize gastric insufflation, jaw thrust, low-pressure squeezes, OPA/NPA, and avoidance of hyperventilation) over advanced airway interventions (ETI, SGA).
- In OHCA, consider transport time and EMS comfort with airway devices/procedures.
- If you are placing an advanced airway, utilize the technique you are most comfortable with, as the research is still equivocal.
- Patients without preexisting respiratory insufficiency and patients with a shockable rhythm tend to do worse when intubated.
A few FOAMed posts on this topic to check out:
- The Young Cardiac Arrest Patientby emDOCs
- Intubation during CPR was associated with worse survival and brain healthby PulmCCM
- SGEM#197: Die Trying – Intubation of In-Hospital Cardiacby TheSGEM
- JC: OOHCA and Airway management. Do we need a tube?by Ashley Liebig
- Episode 108.0 – Intubation in In-Hospital Cardiac Arrestby Anand Swaminathan
- Intubation or supraglottic airway in cardiac arrest; AIRWAYS-2by Simon Liang, Rob Fenwick, and James Yates
- EM Nerd-The Case of the Needless Imperativeby Rory Spiegel
- AIRWAYS-2 Reviewby The Bottom Line
- PART Trial Reviewby The Bottom Line
- Association Between Tracheal Intubation During In-Hospital Cardiac Arrest and Survival Reviewby The Bottom Line
References / Further Reading
- National Academy of Sciences. Cardiac survival rates around 6 percent for those occurring outside of a hospital. https://www.sciencedaily.com/releases/2015/06/150630135103.htm. 12 May 2019.
- Berg RA et al. Adverse hemodynamic effects of interrupting chest compressions for rescue breathing during cardiopulmonary resuscitation for ventricular fibrillation cardiac arrest. Circulation 2001; 104 (20): 2465 – 70.
- Cunningham LM et al. Cardiopulmonary resuscitation for cardiac arrest: the importance of uninterrupted chest compressions in cardiac arrest resuscitation. Am J Emerg Med 2012; 30 (8): 1630 – 8.
- Hanif MA, Kaji AH, Niemann JT. Advanced airway management does not improve outcome of out-of-hospital cardiac arrest. Acad Emerg Med 2010;17(9):926-31.
- Hasegawa K, Hiraide A, Chang Y, Brown DF. Association of prehospital advanced airway management with neurologic outcome and survival in patients with out-of-hospital cardiac arrest. JAMA 2013;309:257–66.
- McMullan J, Gerecht R, Bonomo J, Robb R, McNally B, Donnelly J, et al. Airway management and out-of-hospital cardiac arrest outcome in the CARES registry. Resuscitation 2014;85:617–22.
- Izawa J, Komukai S, Gibo K, et al. Pre-hospital advanced airway management for adults with out-of-hospital cardiac arrest: nationwide cohort study. BMJ. 2019;364:l430. Published 2019 Feb 28. doi:10.1136/bmj.l430.
- Izawa J, Iwami T, Gibo K, et al. Timing of advanced airway management by emergency medical services personnel following out-of-hospital cardiac arrest: A population-based cohort study. Resuscitation. 2018;128:16-23. doi:10.1016/j.resuscitation.2018.04.024.
- Chiang WC, Hsieh MJ, Chu HL, et al. The effect of successful intubation on patient outcomes after out-of-hospital cardiac arrest in Taipei. Ann Emerg Med 2018;71:387–96. 10.1016/j.annemergmed.2017.08.008.
- Sandroni C, Santis P, D’Arrigo S. Capnography during cardiac arrest. Resuscitation. 2018;132;73-77.
- Kang K, Kim T, Ro YS, Kim YJ, Song KJ, Shin SD. Prehospital endotracheal intubation and survival after out-of-hospital cardiac arrest: results from the Korean nationwide registry. Am J Emerg Med. 2016;34(2):128–132.
- Nicholson A, Cook TM, Smith AF, Lewis SR, Reed SS. Supraglottic airway devices versus tracheal intubation for airway management during general anaesthesia in obese patients. Cochrane Database of Systematic Reviews 2013, Issue 9. Art. No.: CD010105.
- Vezina MC, Trepanier CA, Nicole PC, Lessard MR. Complications associated with the esophageal-tracheal combitube in the pre-hospital setting. Can J Anaesth. 2007;54:124–8.
- Benoit JL, Gerecht RB, Steuerwald MT, et al. Endotracheal intubation versus supraglottic airway placement in out-of-hospital cardiac arrest: A meta-analysis. Resuscitation 2015;93:20-6. 10.1016/j.resuscitation.2015.05.007.
- Yeung J, Chilwan M, Field R, et al. The impact of airway management on quality of cardiopulmonary resuscitation: an observational study in patients during cardiac arrest. Resuscitation. 2014 Jul;85(7):898-904.
- Wang HE, Szydlo D, Stouffer JA, et al. Endotracheal intubation versus supraglottic airway insertion in out-of-hospital cardiac arrest. Resuscitation. 2012;83(9):1061–1066. doi:10.1016/j.resuscitation.2012.05.018.
- Wang HE, Schmicker RH, Daya MR, et al. Effect of a Strategy of Initial Laryngeal Tube Insertion vs Endotracheal Intubation on 72-Hour Survival in Adults With Out-of-Hospital Cardiac Arrest: A Randomized Clinical Trial. JAMA. 2018;320(8):769–778. doi:10.1001/jama.2018.7044.
- Benger JR, Kirby K, Black S, et al. Effect of a Strategy of a Supraglottic Airway Device vs Tracheal Intubation During Out-of-Hospital Cardiac Arrest on Functional Outcome: The AIRWAYS-2 Randomized Clinical Trial. JAMA. 2018;320(8):779–791. doi:10.1001/jama.2018.11597.
- Andersen LW, Granfeldt A. Pragmatic Airway Management in Out-of-Hospital Cardiac Arrest. JAMA. 2018;320(8):761–763. doi:10.1001/jama.2018.10824.
- Fouche PF, Simpson PM, Bendall J, Thomas RE, Cone DC, Doi SA. Airways in out-of-hospital cardiac arrest: systematic review and meta-analysis. Prehosp Emerg Care. 2014;18(2):244-256.
- Andersen LW, Granfeldt A, Callaway CW, et al. Association Between Tracheal Intubation During Adult In-Hospital Cardiac Arrest and Survival. JAMA. 2017;317(5):494–506. doi:10.1001/jama.2016.20165.
- Yamada A, Takeuchi Y, Nishizaki Y, et al. Bag-valve-mask ventilation with airway adjuncts improves neurological outcomes of in-hospital cardiac arrest. Intern Med. 2012 ;51(12):1517-21.
- Salim Rezaie, “In-Hospital Cardiac Arrest: The First 15 Minutes”, REBEL EM blog, April 27, 2017. Available at: https://rebelem.com/hospital-cardiac-arrest-first-15-minutes/.
- Andersen LW, Raymond TT, Berg RA, et al. Association Between Tracheal Intubation During Pediatric In-Hospital Cardiac Arrest and Survival. JAMA. 2016;316(17):1786–1797. doi:10.1001/jama.2016.14486.
- Gupta P, Rettigant M, Gossett J, et al. Association of presence and timing of invasive airway placement with outcomes after pediatric in-hospital cardiac arrest. Resuscitation. 2015 Jul;92:53-8.
- Hansen ML, Lin A, Eriksson C, et al. A comparison of pediatric airway management techniques during out-of-hospital cardiac arrest using the CARES database. Resuscitation. 2017;120:51–56. doi:10.1016/j.resusci