Grand Rounds Recap March 30, 2016

M&M with Dr. LaFollette

Modified Sgarbossa Criteria to aid in diagnosing STEMI in the setting of LBBB

LBBB. By Steven Fruitsmaak (Own work) [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0) or GFDL (http://www.gnu.org/copyleft/fdl.html)], via Wikimedia Commons

• Can be used in the setting of induced (paced) LBBB
• Unweighted scoring (any of the following indicates STEMI equivilance)
  • Concordant ST elevation
  • Concordant ST depression in V1,V2,V3
  • Inappropriate discordance of >25% ST elevation / S wave amplitudes
• Improves your test metrics from the original criteria from sens/spec of 36%/96% to 80%/99% respectively in a new validation study

Aortic Dissection and cognitive bias

• Anchoring is something we must constantly be aware of and this is a case of search satisfying in the setting of STEMI, as well as Diagnostic Momentum / Sunk Costs inherent to cath lab activation
• Croskerry et al have a great article regarding these diagnostic biases we encounter daily and must acknolwedge in order to avoid

Proximal Aortic Dissection presenting as STEMI

• Rare - only 15% have involvement of the coronary arteries, only 1/3 of those (5%) present as STEMI
• 50% involve RCA only, while up to 20% effect LAD/LCx only and the remainder involving both

Difficulties diagnosing STEMI in setting of LVH

• Armstrong et al. did a review of 411 STEMI activations in SF Bay area with a 79% false activation rate in the setting of ECG-defined LVH
• This likely owes to precordial repolarization abnormalities intrinsic to LVH that get accentuated in the setting of increased voltages.
• Using a step-wise rule comparing the ST segment to the overall RS amplitude (>25% is STEMI in >3 leads), they were able to  improve the AHA reccomendation's sensitivity and specificity of 73% and 58% to 77% and 91%, respectively> This would significantly decrease false cath lab activations, but is it ready for primetime? Needs some external validation but a step in the right direction
• Continue to use your clinical gestalt of the patient and when in done, repeat EKG, repeat examinations and repeat troponins will be your saving grace.

Blunt Cardiac Injury (BCI) is something we rule out not infrequently; it is worth knowing what the EAST Guidelines recommendations are:

• All patients with suspected BCI should get a screening EKG
• In suspected patients with BCI, EKG and troponin are sufficient to rule out BCI (100% NPV)
• Sternal fracture alone does not predict the presence of BCI

Hepatitis C... acutely? Make sure you're ordering the right tests

• Symptomatic acute Hepatitis C is rare - only 30% of those infected have symptoms
• Only Hep C antibodies are included on an acute hepatitis panel, and these can take up to 7-10 weeks to trigger positive
• Viral RNA for Hepatitis C are present shortly after infection and should be added if high clinical concern

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Taming the SRU: Stroke Mimics with Dr. Mudd

A 71 yo female with fall down stairs, neck pain and cervical fractures and right hemiparesis.

- work quickly through every stroke evaluation as time if of the essence, but keep stroke mimics in the front part of your mind

- spinal epidural hematomas, especially those in the lower cervical spinal cord and superior thoracic spinal cord can compress the spinal cord from one side and cause hemiparesis

- spinal epidural hematomas can occur spontaneously, especially in anticoagulated patients, and can present with hemiparesis without cranial nerve deficits; the only physical exam finding to direct you towards this diagnosis may be new neck pain with onset of symptoms

- approximately 25% of cervical spinal epidural hematomas present with hemiparesis

- situational awareness of all patients in the SRU is important, utilize the resources you have available to get things done quickly and efficiently for your patients

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Case Follow Up: Status Asthmaticus with Dr. Plash

-Severe asthmatics can be extremely difficult to manage. If standard nebs and steroids aren't working, can consider these interventions.

-IM epinephrine, same dosing as anaphylaxis, for life threatening exacerbation

-Magnesium, 2g IV, for life threatening exacerbation, or failure to respond to standard therapy in 1 hour (decreases admission rate)

- BiPAP is reasonable to try given reversible nature, but has never been shown to be beneficial in limited asthma studies

- Intubation should be avoided in asthmatics if possible, but if you have to, vent management is difficult

- Follow plateau pressures, not peak pressures (peaks are dynamic, dependent on airway resistance, and will always be elevated in asthma)

-Possible causes of high plateau pressures- auto-peep/breath stacking and pneumothorax

-Permissive hypercapnia (pH 7.15-7.2)

-Can do bicarb, carbicarb, or THAM drip to increase pH

-Maximize I:E ratio (1:4, 1:5, or more)

-Consider ketamine for induction and sedation if you do decide to intubate given bronchodilatory effects

-Beware secretions with this

-Heliox might decrease airway resistance and deliver nebs better with relative little downside

-ECMO (V-V in general) is a salvage therapy for failure to respond to maximal therapy, but asthma patients very rarely require this

-However, ECMO outcomes are better in asthma than other disease processes, so worth it in someone truly failing to respond