Triage: Cardiac Arrest
History of Present Illness: A man in his early 70’s is brought to the ED by medics after being found down in the garage by his wife, who speaks limited English. He was cyanotic and hypotensive with pulse ox and SBP both in the low 70’s. Medics gave push-dose Epi x 2 and placed an LMA. He then briefly lost a pulse and got one round of CPR before medics obtained ROSC.
Vital Signs: BP and pulse ox now up to low 90’s. HR 132 but remember he got Epi.
Physical Exam: Patient initially unresponsive with bag-valve-mask ventilation but breathing over bag-valve-mask seeming to breathe pretty fast with no palpable pulses and CPR started. Later on patient gradually got his pulses back maintain them gradually woke up and we were able to take out the LMA and now is still a little bit sleepy but is able to answer questions and denies any symptoms.
Initial Diagnostic Testing:
- Imaging: see bedside cardiac US below. Only sub-xiphoid images could be obtained. Multiple attempts at a parasternal view were unsuccessful
- Abdominal US showed no free fluid no enlarged aorta.
- Chest x-ray was negative.
Additional history: After patient started to gradually wake up he was extubated and related that he had been working outside on some fencing and thought he probably fainted. He still felt very weak but had no other symptoms and limited recall of events.
Additional testing: Leg duplex negative. troponin 5.6 repeat troponin 30, potassium 3.2, bicarb 19, lactic acid 6. WBC 18. All of these values could be simply due to epinephrine and/or the prolonged syncopal episode.
What is the most likely diagnosis (may choose more than one)?
- A) Anaphylaxis
- B) PE
- C) CO toxicity
- D) Pneumothorax
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What is the most likely diagnosis?
- A) Anaphylaxis – CORRECT – he was outside, and responded to epi. Once he was fully awake he notices a pain and a welt to the back of his neck, likely from a bee
- B) PE – unlikely as would have enlarged RV on his echo with this severe of a clinical presentation. The view shown is normal
- C) CO toxicity – good thought as found in garage but the CO level was normal.
- D) Pneumothorax – ALSO CORRECT AS UNABLE TO GET PARASTERNAL VIEW ON ECHO – Not seen on CXR but was seen on CT. Was likely from the CPR.
1-Minute EM Consult on the topic for this case from the Emergency Medicine 1-minute Consult Pocketbook
CASE CONCLUSION: There was a small PTX explaining inability to obtain parasternal view on US. Troponin peaked 250 at and lactic acid at 6. Serum tryptase came back a few days later and was elevated at 66 (ULN <11). The literature shows that the incidence of PTX after CPR is as high as 11%, but most are occult on CXR and only seen if CT is done. Click on link below for more.
Post-resuscitation pneumothorax: retrospective analysis of incidence, risk factors and outcome-relevance