Monday, January 11, 2016

The "tunnel vision" of ACS!

This week, I have a case to share. It was a couple of years back when I came across this one.

10:45 AM    33 year old guy walked into the ED complaining of chest pain, sudden onset, left sided, continuous, funny sensation, no aggravating or relieving factors, 6-7/10 scale, no nausea/sweats/vomiting, No fever or any other recent illness. No other co morbidities or similar previous episodes. Not on any medications, No Allergies, Non Smoker, Not an alcohol consumer.

10:54 AM    ED ECG: 92/min, NSR, Normal axis, No ST-T changes

10:58 AM    General Exam: Comfortable, No Pallor, Icterus, Cyanosis
VS: PR 96/min, BP 110/80, SpO2 98%, RA, RR 18/min T 98F
Exam was documented as normal

11:05 AM    He got Paracetamol PO

11: 20 AM    ED ECHO - No RWMA
A few more ECGs were done over next 2-3 hours but they all looked normal. Labs sent.

12:00 PM     First Troponin reported - Normal (CBC, ESR, Renal function - All with normal limits)

12:10 PM     Pain was persisting so Cardiology was called in for their EXPERT opinion, because we were not sure about the cause of chest pain and thought its probably a MSK pain or atypical ACS.

12:50 PM     Cardiology Consultant walked in, Everything happened once again (History, Physical) and then what? Yes, one more troponin and one more shot of pain killer.

01:30 PM     He got a NSAID this time and troponin was sent (once again reported back as normal)

02:00 PM     Time for shift change and handover in the ED. This guy got handed over to a new set of residents who fortunately once again examined him and found something different this time.

Breath Sounds: Decreased (not absent) on the left side, his RR interval was fluctuating on the monitor as well as on the ECG, could be sinus arrhythmia or something else. They decided to do a CXR this time that was not done so far. And here is what the CXR looked like!!

Left sided Spontaneous Pneumothorax 
So, this guy who came with a typical Pnemothorax story was getting worked up for ACS. ECGs, cardiac biomarkers, routine labs and Echo were done but a CXR was skipped! He eventually got admitted, did well and got discharged. But we took about 5 hours to reach the diagnosis for a classical presentation in the ED. Lets see what made us pick this one up eventually and what could have been done to avoid this at the first place:

When the new team of residents took over this patient, a quick re examination made pick this finding. After handover, it is always good to tell patients what you have been told about them. Do they have anything else to tell you? You would be surprised to hear new information many times, that can actually make a difference. Make this a habit.

If you go back and look at the respiratory rate on this man, it was 18bpm. Well that is not normal. Normal RR is 12-14 bpm. 18 is definitely above normal. This can be either tachypnea or dyspnea! Make sure you always count and document the RR. We all like "even numbers" but it is not fair to write just another even number here. Count the RR, look at the respiratory effort and document it. This is a VITAL SIGN. Respect it.

When the RR interval shows quite a bit of fluctuation on the monitor, get a ECG STAT. Things that you should think about are A.Fib, A.Flutter, AV blocks, Pneumothorax or sinus arrhythmia. ECG changes in pneumothorax have not been extensively described in literature (like pulmonary embolism) but do remember that any lung pathology can produce ECG changes. So always think beyond ACS for every chest pain when the first ECG looks normal. 




Chest Pain can be due pathology in any of these organs:
Heart, Lungs, Aorta, Oesophagus, Stomach, Pancreas, Ribs, Pleura, Pericardium etc. But when you call in a consult from any speciality, do not expect a thorough review of the patient by them. Most of them focus only on their area of focus and there is nothing wrong with that. In fact, that was the reason why you called them at the first place, to evaluate the heart (in this case). I am pretty sure that a Pulmonologist would have picked this up instantaneously with examination/ CXR or USG because that is how they are trained.
It is only the internists, emergency and critical care personnel that evaluate the patient completely. With no offence to any specialists and sub specialists, as they specialise more and more, they focus on only a few diagnosis related to their pertinent organs or organ systems. You as a emergency physician, do not have that luxury. The brunt of missing a diagnosis always and always falls on the ED no matter how many specialists have evaluated the patient. 

You might also consider having a ED Chest pain USG protocol which scans all chest pain patients for RWMA, Dilated RV, fluid around the heart/lungs and Pnemothorax. USG is undoubtedly an extension of physical examination, it will take a few more minutes at the bedside and give you vital bits of information. 

Take Home
  • Re-examine patients after you take the handover.
  • RR of 18 is not normal. Count the RR, look at the effort and then document that.
  • PTx may have decreased breath sounds not necessarily absent breath sounds.
  • Every chest pain is not ACS - go beyond it and think PE, PTx, Dissection based on History and examination!
  • Have a chest pain ECHO protocol to look at RWMA, Dilated RV, Fluid around the heart/lungs and a pnemothorax!

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