Review of: Abo BN, Hostler D, Wang HE: "Does the type of out-of-hospital airway interfere with other cardiopulmonary resuscitation tasks?" Resuscitation. 72(2), 234-239, 2007.
Twenty two-paramedic team completed two videotaped advanced cardiac life support (ACLS) scenarios on a human simulator. The simulated patient remained in V-Fib throughout the scenario, and the teams were randomized to either establish an airway using the Combitube or endotracheal intubation. The time to perform three shocks, establish an airway and IV, and deliver the fourth shock were recorded. The time during which no chest compressions were being performed was also recorded. The teams were following the 2000 AHA guidelines.
The study showed that the time required to establish an airway using the Combitube was significantly less than endotracheal intubation (median difference 26.5 seconds). Time without chest compression was less for Combitute than endotracheal intubation (median difference 8.5 seconds). The method did not impact time to establish IV placement, deliver meds or perform the fourth shock.
The authors conclude that the time required to establish an airway and decrease no compression time was better with the Combitube than with endotracheal intubation.
I ll go ahead and present my bias that we should be moving to the non-visualized airways in cardiac arrest. However, I can't use this study to substantiate this. While I respect the authors for their continued attempts to examine the effect of various airway approaches on cardiac arrest, I believe this study only confuses the issues.
First of all, the teams were using the 2000 AHA guidelines, which didn't accent the critical importance of non-stop chest compression. Secondly, the teams of two medics isn't reflective of the typical pre-hospital cardiac arrest scene where first responders, law enforcement, by-standers and other EMS personnel are available to perform chest compressions during airway management. The authors imply the differences they saw in the simulator would be greater in the field given. I'm not so sure.
Although there is no question that a Combitube can be inserted faster than the ET tube, this study doesn't really answer the question it asks: Does airway management in any form interfere with chest compression? In the discussion section of the article, the authors present data from several papers based on the 2005 guidelines. To use the data gained from these medics performing what at the time was "state of the art" CPR doesn't compare apples to apples.
What are necessary are simulations that are more realistic. Place the simulator in the bathroom with poor lighting. Add a couple of "extra" hands like those I listed before and make sure the crews are well trained in the 2005 guidelines. Then we can see the effect. If was some way to avoid the potential liability issues existed, I'd love to do a study with a camera attached to the medic existed s head, record real-life codes and then make recommendations.Until then, we must continue to examine the data but do so using scenarios as close to reality as possible.