POCUS in ACLS Algorithm
Multiple protocols have been designed with the intent of integrating POCUS into advanced cardiac life support (ACLS safely). However there is no single best approach is widely accepted as best practice. What is clear though is that time is of the essence in arrest cases and a clinician should avoid exceeding the 10 second pauses between chest compressions. POCUS should not be used for prognostication purposes. As of now it is acceptable to continue resuscitation efforts that end up proving futile than to erroneously terminate resuscitation in a patient who would have otherwise survived.
The following is a concerted attempt at facilitating your differential while following best practices. To learn more about the theory behind the use of POCUS click here. Before you start make sure you have followed best practices here. To proceed click start.
Best Practices for the use of POCUS in ACLS
POCUS should only be used during rhythm check and should not interfere with CPR efforts
Prepare the curvilinear or the phased array probe so that image acquisition lasts 10 seconds. When you click the 'aquire' button, it usually records only 3 seconds of your scan and may not be time enough for you to record.
Appoint a 'Time Keeper' so that POCUS lasts less than 10 seconds.
On pulse check ONLY acquire. Interpret images when chest compressions have resumed.
During the time of chest compressions, the sonographer can look at extra cardiac images such as Lung/Abdomen/ Vascular.
Communicate results with the rest of the team.
You should continue to obtain more scans once you have returns of spontaneous circulation to verify your impression or to change management.
PEA vs Shockable rythms
Your are seeing a True PEA an thus need to continue to look for a reversible cause:
Ultrasound will not be able to help you with the following differential diagnosis and you should tackle them as you proceed with this algorithm:
1. Hydrogen ion. Acidosis.
4. Hypokalemia/ Hyperkalemia.
Based on the images displayed the differential diagnosis:
1. If you see a wide complex QRS, this is VT or VF. In which case defribillation is warranted.
2. If you observe a narrow complex QRS this is SVT. In which case synchronized cardioversion is warranted.
Address hypoxemia by either Mask Ventilation, placing an Laryngeal Mask Airway and performing intubation as recommended by the ACLS guidelines. Ultrasound at this point may help you understand the cause of hypoxemia if the cardiac arrest was secondary. Look at both the lung and the gastric antrum. Pneumothorax determination next:
Presence of normal filled ventricles and a collapsed inferior vena cava is suggestive of hypovolemia. You may not see a collapsed ventricles. Should any of the following images are seen, consider acute blood loss anemia and FAST exam.
Rule out cardiac tamponade by NOT seeing pericardial fluid.