The Agony of the Beta Agonists PART 2 AUGUST 2015

We left off with a rather critically ill patient. EMS responded to a patient in respiratory failure:

The Agony of the Beta Agonists PART 1 of 2 JULY 2015

This was shared from a friend, provider, and colleague. Interesting case. Details changed to protect the innocent, respect privacy laws, comply with all appropriate regulations, and, well.. you get the picture.

SUBJECTIVE
HPI:
94 yo male requests 911 for shortness of breath. HPI  not obtainable due to patient presenting in extremis. The patient is alert, responsive to verbal stimuli, and is in obvious respiratory distress upon arrival. Providers appreciate audible wheezing. Family members relate that the patient is a "DNR" and was last seen acting "a little tired" 12 hours prior.
Meds: Unknown
PMH: COPD, CHF, HTN, HLD, DM

OBJECTIVE
Pt is slightly diaphoretic. BP: 134/92, R: 32, P: 90. ETC02 via NC is 20.
Supraclavicular and intercostal retractions are present as is mild JVD.

The patient's ECG was similarly concerning:

Let's review this case: 

PREHOSPITAL TREATMENT 

Prehospital treatment should be directed at symptom relief and mitigation of the underlying cause. Audible wheezing does not always indicate COPD, and this patient may be suffering from CHF, cardiac asthma, pneumonia, or a combination of entities! Fortunately, CPAP therapies have utility with respect to reducing the work of breathing and reducing preload. Of course, the concurrent rise in intrathoracic pressure may precipitate hypotension. However, this patient is alert enough to probably warrant a trial of non invasive positive pressure ventilation. Beta agonists may have utility if there is evidence of bronchospasm. However, B1 receptor stimulation may cause an increase of cardiac contractility and irritability. Nitroglycerin

wouldn't be unreasonable, but its probably safe to consider initiating IV access. The take home point in this case is that elderly patients are often highly comorbid. Physical assessment and end tidal C02 readings are often confounded by the critical presentation! Is the patient's end tidal reading low due to tachypnea alone? Is there an underlying metabolic disturbance? Is the wheezing due to bronchospasm or does it represent sequelae of pulmonary edema? Often times, more information is needed in the form of xray and bloodwork to determine the underlying diagnosis- or diagnoses. CPAP and other respiratory treatments represent reasonable therapies, and there is no all inclusive, correct answer. There is really no role for the emergent, prehospital administration of furosemide for suspected acute cardiogenic pulmonary edema. If the patient can follow the occasional verbal commands and swallow without difficulty, 325 mg of chewable aspirin is indicated. 

ECG FINDINGS AND STEMI ALERT? 
The underlying rhythm appears sinus in origin and there is evidence of a left bundle branch block (LBBB). LBBB is a common finding in elderly patients and may simply represent advanced disease. LBBB accompanies a relatively rare number of acute myocardial infarctions and is a maker of illness severity when present. A complete LBBB results from interruption of the anterior and posterior fascicles. Therefore, new onset LBBB in the setting of a critically ill patient should motivate EMS personnel to transport to a facility capable of percutaneous coronary intervention. LBBB often confounds the diagnosis of STEMI but recent literature and AHA guidelines recommend against activating the cath lab for an LBBB of unknown duration. In this setting, however, where providers are confronted with a patient in acute pulmonary edema, it may be wise to choose a cath capable hospital. 

SUBTLE SGARBOSSA

Criteria exist for the prediction of ischemia in the presence of LBBB. The Sgarbossa crtieria function to distinguish ischemia (terrible) from pre-existing conduction delay and established coronary artery disease (less terrible). In this ECG,  specifically in Lead V3, there is evidence of an "excessively discordant ST segment." In previous studies, the presence of discordant ST elevation (in leads with a negatively deflected QRS) was associated with myocardial infarction. This criteria alone is not sufficient to establish the diagnosis of STEMI but may bolster the provider's decision to transport to the cath lab. An excellent discussion of the original Sgarbossa criteria can be found on the Life in the Fast Lane Blog.