Case summary

An ALS crew was called to a 30s male in cardiac arrest.  When the crew arrived, they found bystanders performing CPR and learned an AED had been used to shock the patient twice before they had arrived.  The EMS crew took over CPR and placed the patient on their monitor.  They found that the patient was in ventricular fibrillation (VF) so they immediately shocked the patient and continued CPR.  Mechanical CPR device was placed and they checked the rhythm two minutes after the first shock to find that the patient was still in VF.  Patient was shocked through compressions and worked on an advanced airway and vascular access.  Endotracheal tube (ETT) was placed just before the next rhythm check which again revealed VF, so the crew shocked a third time.  On the next rhythm check, they found the patient to have a strong pulse and that the patient was in sinus rhythm.  They obtained the following vitals after getting return of spontaneous circulation (ROSC):

Vitals: HR 160,  BP 180/100,  RR 7, ETCO2 32,  Sat 99% on 15L

The patient was biting the ETT and breathing over their attempts to bag the patient so they gave the patient IV midazolam for sedation.  The crew also obtained a 12-lead EKG to look for STEMI, but no STEMI was present.  Right after loading the patient in the ambulance, they noted his HR was 220 and he was in a regular narrow complex tachycardia consistent with supraventricular tachycardia (SVT).  The patient had no clinical signs of shock and still had a strong pulse.  The crew called online medical control to discuss giving adenosine or going straight for electrical cardioversion.  Online medical control recommend going straight for electrical cardioversion given tachyarrhythmias in post arrest patients should be presumed unstable.  The crew performed synchronized cardioversion and converted the patient to a sinus rhythm.  Patient remained stable and was transported to the nearest cath lab capable center for further assessment and care. 

 Highlights of the case:

In cardiac arrest care, we use C-A-B, not A-B-C.

For patients in cardiac arrest, there many things we need to do in a short period of time.  Often there is only one medic on scene, so it is important to know what takes priority.  The order in which we do things is: chest compressions, pads to check rhythm, electricity (if indicated), IV/IO access for epi, advanced airway.  Historically we have focused on airway early hence why we have described this care as the A-B-Cs of resuscitation.  However, more recent studies have found that for most cardiac arrests, it should be the C-A-Bs of resuscitation meaning we prioritize support of the heart over airway.  Placing an advanced airway should almost never take priority over the other things listed ahead of it since BLS airway techniques are often sufficient while the more important interventions are being performed first.  If there is enough responders that all of this can be done simultaneously then that is completely fine.  This crew provided amazing cardiac arrest care and performed all key interventions in the proper order.

Continue chest compressions while the monitor is charging.

The goal is to minimize pauses in compression during cardiac arrest.  The longest we should ever pause is 10s, but shorter pauses are better to minimize no flow time to the heart and brain.  This is also why we should NEVER hold compressions for placement of an endotracheal tube.  When we find a patient with a shockable rhythm, we should continue compressions while the device charges in order to minimize these pauses in compressions.  If we are doing manual compressions, we will then pause compression long enough to shock and then immediately get back on the chest without re-checking pulse or rhythm until the next check two minutes later.  If we are using a mechanical compression device, we only need to pause for the pulse and rhythm check.  We can turn the compression device back on for the charge and can defibrillate while compression are ongoing since this does not damage these devices.  This crew ensured the highest compression ratio by restarting manual compressions while their monitor charged.

Cardiovert for unstable tachycardia

Once the crew obtained ROSC, they noticed that the patient was in a regular, narrow complex tachycardia that looked like SVT.  This was the correct decision in this situation.  Given that the patient had just been in cardiac arrest, it is fair to say that this was an unstable tachyarrhythmia.  For all unstable tachyarrhythmias, the treatment is immediate cardioversion.  Medications are only indicated if the patient is completely stable.  There is a chance that this was sinus tachycardia, but if this was the case, cardioversion will not harm this patient.  If you cardiovert sinus tachycardia, the rhythm will not change.  However, if you fail to cardiovert an unstable tachyarrhythmia, the patient can die.  For this reason, if there is any doubt, it is best to cardiovert in these situations.

Involve online medical control when unsure what to do.

This crew was not sure the best way to treat this patient’s SVT.  This patient had a solid BP and no signs of shock pointing towards stable SVT; however, this patient was just in cardiac arrest, and these patients are inherently unstable.  This was a grey area; therefore, it was wise of the crew to discuss with medical control just as they did.  When in doubt it is better to double check something with medical control to make sure our plan of care is optimal.