Here's a great case submitted by a faithful reader who wishes to remain anonymous. Some minor details have been changed to preserve patient confidentiality and some relevant comments and teaching points have been added.
EMS is called to a barbecue festival for 60 year old male, unconscious and unresponsive, possible cardiac arrest.
En route dispatch advises, "the caller states the patient is breathing, CPR in progress."
While radio transmissions like this often make EMTs and paramedics chuckle, we know that agonal breathing helps predict survival from sudden cardiac arrest.
This is one of the reasons that "look, listen and feel" has been removed from the 2010 AHA ECC guidelines.
"Agonal gasps are common early after sudden cardiac arrest and can be confused with normal breathing. Pulse detection alone is often unreliable, even when performed by trained rescuers, and it may require additional time. Consequently, rescuers should start CPR immediately if the adult victim is unresponsive and not breathing or not breathing normally (ie, only gasping). The directive to "look, listen, and feel for breathing" to aid recognition is no longer recommended."
On arrival, bystander CPR is in progress. Specifically, continuous chest compressions without rescue breathing are in progress. An EMT takes over compressions and the following sequence happens very quickly.
- The LP12 is powered on.
- The combi-pads are deployed and attached to the patient.
- The LEAD button is pushed to get a paddles view.
- The monitor is charged to 200 J.
This is where the "pit crew" concept or "choreographed model" comes into play. There is no reason to hesitate. The monitor should be charged immediately with the expectation that it's a shockable rhythm so that the shock can be delivered as soon as possible.
(Since some are claiming this is "dangerous" please see:
M.S. Lloyd, B. Heeke, P.F. Walter, J.J. Langberg. Hands-on defibrillation: an analysis of electrical current flow through rescuers in direct contact with patients during biphasic external defibrillation. Circulation 117 (2008) (2510 – 2514).
Edelson DP, Robertson-Dick BJ et al. Safety and efficacy of defibrillator charging during ongoing chest compressions: a multi-center study. Resuscitation. 2010 Nov;81(11):1521-6.)
Once these actions are complete, everyone clears the patient with the exception of the chest compression man. When the lead paramedic gives the command (in this case a nod of the head) the chest compression man clears the patient, the lead paramedic confirms that VF is on the monitor, and the shock is delivered with minimal delay between stopping compressions and shocking.
Compressions are resumed immediately. The pulse check does not occur until another complete 2 minute cycle is complete.
Incidentally, some of the highest performing EMS systems in the country handle this in differrent ways. Some perform continuous chest compressions with a non-rebreather mask, some follow the 30:2 recommendation of the AHA (occasionally with a ResQPOD attached to the BVM), others drop a blind insertion airway device like the King LTS-D and deliver asynchronous ventilations at a rate of 8-10/min. (every 6-8 seconds), and some capture the airway with a tracheal tube without interrupting chest compressions.
As the next 2-minute cycle is nearing completion the monitor should be charged again to 300 J (or whatever energy setting your protocols dictate for the second shock). Again, the idea is to avoid ineffficiency.
It shouldn't look like this:
- Stop compressions
- Read the monitor and decide the patient needs a shock
- Start compressions again
- Charge the monitor
- Stop compressions
- Confirm that a shockable rhythm is on the monitor
- Go through a lengthy "I'm clear, you're clear, we're all clear" process
- Deliver the shock
On the other hand, it is very important that the paramedic who interprets the monitor pay close attention to whether or not it's a shockable rhythm before pushing the SHOCK button.
This can be diffficult when the defibrillator is pre-charged, everyone's watching, and you're trying to balance minimizing the delay between stopping compressions and shocking with making sure the shock will confer a benefit to the patient.
After the second shock it was noted that the patient was "pinkening up."
The defibrillator was pre-charged prior to the end of the next 2 minute cycle. However, this time there was a rhythm on the monitor. It looked something like this.
The patient started to breath spontaneously at a rate of about 30/min which was somewhat surprising. The "airway man" attached the waveform capnography to the BVM and timed small bag squeezes with the patient's spontaneous ventilations.
This works beautifully if you haven't tried it! Waveform capnography is a very useful tool.
Once the patient was loaded in the back of the ambulance a 12-lead ECG was captured.
Vital signs were assessed.
Pulse: 150 Irregular
NIBP: 155/123 (presumed spurious)
SpO2: 97 and rising
An EMT attempted to confirm the BP by auscultation but was only able to confirm a BP of 150/P.
At this point it was noted that the patient was moving and there was a small amount of vomit in the patient's mouth.
The patient's airway was suctioned (with difficulty due to a clenched jaw). After a minute or two the patient's jaw relaxed.
The OPA was removed in case the problem was a return of the patient's airway reflexes. By this time the respiratory effort was adequate and the decision was made to switch the patient out to a non-rebreather mask. The patient's head was turned to the side.
This had a positive effect and within a minute or two the patient followed a command to open his eyes.
Another 12-lead ECG was captured.
By arrival at the hospital the patient was confused but talking.
Questions for discussion
Do you follow a "pit crew" concept or choreographed model for sudden cardiac arrest?
What is a normal response in your jurisdiction for sudden cardiac arrest?
Have you read the 2010 AHA ECC Guidelines?
Do you emphasize minimally interrupted chest compressions, controlled ventilations, and shocking in a 2-minute cycle?
Are all other interventions secondary?
Do you think this patient needed antiarrhythmics?
What do you think of the patient's 12-lead ECGs?
What should this patient's post-resuscitation care look like?