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EMS Today2018

EMS Myths

Corey M. Slovis, M.D.Vanderbilt University Medical Center

Metro Nashville Fire DepartmentNashville International Airport

Nashville, TN

NTG in Inferior AMIcan you use it – even

if RV Infarct?

5 Ways to Diagnose an AMI

1 mm of ST elevation in 2 or more anatomically contiguous leads

Reciprocal ST Depression

Q Waves

Compared to prior ECGs

Compare to next ECG in 15-30 minutes

Reading for AMI3 at a Time, Not 12

2, 3, F Inferior

I, L Lateral

V1, V2, V3 Anteroseptal

V4, V5, V6 Anterolateral

↑ AvR, V1↓, V2 ↓ Left Main, RV, Posterior

R > ST ↑

ST ↓

Posterior AMI

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Optimal AMI Care

• ASA and Plavix (2b-3a at PCI)

• NTG

• Lytic or Lab

• Heparin (LMWH or UFH) or heparinoid

• Beta Blockade (within 24 hours)

Nitrates

• Decrease Preload

• Decrease Afterload

• Decrease O2 Consumption

• Saves Myocardium

• May Decrease Mortality

Acute Hypotension with NTG5 Causes

• Inferior AMI (especially RV involvement)

• Relative or Absolute Volume Depletion

• Viagra, Levitra, Cialis

• Drug Sensitivity (valvular dsx, idiopathic)

• Bezold-Jarisch Reflex

Am J Card 1989 ;64:311-14

Does NTG increase hypotension in inferior AMI and is it worse if RV involvement?

• 40 pts with inferior AMI

• Compared 20 pts who had BP to NTG to 20 patients who did not develop BP to NTG

• Compared 30 mm sys BP to RV involvement

• Used ST in V1-V2 as marker for RV

75% of Inferior AMI pts who developed hypotension had RV

involvement by ECG and/or other methodology

Am J Card 1989 ;64:311-14

“A marked hypotensive response in an Inferior AMI suggests RV involvement”

Am J Card 1989 ;64:311-14

In these patients “nitrates should be administered carefully”

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Nitroglycerin does

NOT

Improve Survival In AMINitroglycerin in AMI

• 1,466 STEMIs, 56% received NTG

• Montreal Quebec EMS 2010-2012

• Evaluated BP changes in Inf vs Non-Inf AMIs

• BP < 90 or BP > 30mm Hg s/p NTG

Prehosp Emerg Care 2016;20:76-81

How dangerous is NTG in Inferior AMI?

0%

5%

10%

15%

20%

25%

STEMI BP Changes Post NTGPrehosp Emerg Care 2016;20:76-81

BP < 90 BP > 30mm Hg

8.2

Inf Not-Inf Inf Not-Inf

23.4

P=NS P=NS8.9

23.9

Does the HR predict BP in chest pain pts treated with nitroglycerin?

• 10,308 pts from Montreal EMS

• 20% of pts (2,057) were tachycardic pre-NTG

• NTG dose was 0.4 mg spray

• NTG repeated Q5 if CP persisted

• 3.1% of all pts developed hypotension s/p NTG

Prehosp Emerg Care 2017;21:68-73

0.0%

0.5%

1.0%

1.5%

2.0%

2.5%

3.0%

3.5%

4.0%

2.9%

NTG and Hypotension

WNL HR

Prehosp Emerg Care 2017;21:68-73

3.9%

HR

35%

P=0.02

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decreased by 36% for every 10 mm Hg of systolic BP

Above 100 mm Hg

Probability of Hypotension NTG and Hypotension

Take Homes

• Inferior and Anterior AMI hypotension equal

• Beware borderline BPs

• Especially if the pt is tachycardic

• EMS and hospital personnel should be prepared for BP especially in those who are tachycardic, regardless of Inf AMI or Ant AMI

Beware ST depression in V1, V2

of RV and/or posterior involvement

ST AVRInferior AMI

R T ↑

ST ↓

and Posterior AMI

R > ST ↑

ST ↓

Posterior AMI

Posterior AMI Nitrates in AMITake Homes

• May cause hypotension, be careful

• Does not affect mortality, only pain

• Excellent if hypertensive

• Be careful especially if tachycardic, with a borderline BP or with ST depression in V1, V2 or signs of a posterior AMI

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EPI

Ann Allergy Asthma Immunol 2017 ;119:108-10

Epinephrine is not used enough in anaphylaxis. Quotes multiple studies:

• UK study: 40% of deaths had no epi

• Only 19% of pts with anaphylaxis got epi in large US study

• Only14% of pts with anaphylaxis in large European study got epi

Ann Allergy Asthma Immunol 2017 ;119:108-10

Epinephrine is not used enough in anaphylaxis. Quotes multiple studies:

• Yet 90% get antihistamines

• And 50% get steroids

Ann Allergy Asthma Immunol 2017 ;119:108-10

How often is epinephrine given before or in ED?

• 408 children with anaphylaxis, x are 7.25 yrs

• Only 1/3 got epi pre-ED

• 2/3 of at school anaphylaxis treated

• Nuts > milk > egg > seafood > unknown

• organ system involvement = of epi

Ann Allergy Asthma Immunol 2017 ;119:108-10

Key Findings

31% of children who had not received epinephrine pre-ED or Urgent Care – did not receive it once they were at the ED or UCC

Twice as many patients who never received epi prior to ED arrival required hospital admission

“Epinephrine administration is not contraindicated in the treatment of anaphylaxis in patients with known

or suspected CAD”

Curr Opin Allergy Clin Immunol 2016;16:352-60

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• 340 normotensive patients with anaphylaxis

• 40 developed hypotension

• Epinephrine use decreased risk by 75%

Adrenaline use resulted in a lower risk of developing hypotension

(OR = 0.254; P = 009; 75% decrease)

Sci Rep 2016;6:20168J Allergy Clin Immunol Pract 2015 ;3:76-80

• 301 pts from Mayo Clinic

• Complications compared for IV vs IM

• 4 ODs and 8 CV events

J Allergy Clin Immunol Pract 2015 ;3:76-80

• IV epi caused all ODshypotension, ischemic ECG and positive Trop

• IM epi no ODs, 2 HTN, 1 angina

• IM epi in 76 yo F + Trop(0.3 IM by pt plus 0.4 mg IM in ED)

• 4 patients all had major complications with epinephrine for anaphylaxis

• Cardiogenic shock, STEMI, coronary dissection, VTach

All patients erroneously got IV Epi at doses of 0.3 IVP to 2 mg IVP

Annal Emerg Med 201055:341-4

1.0 mg IM for anaphylaxis caused STEMI with thrombus

Am J Emerg Med 2013;31:1157.e 1-3Ann Allergy Asthma Immunol 2011 ;106:401-6

• 220 pts from Mayo Clinic with anaphylaxis

• ¼ were older than 50 yo

• 12.7% were older than 65 yo

• Older patients had more hypotension

• Older pts discharged less often with epi injector(1/3 vs 2/3)

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Multicenter online registry of epinephrine administration for

anaphylaxis

Int Arch Allergy Immunol 2017;173:171-7

Stroke

Should you use a stroke scale to decide on going to a

Comprehensive Stroke Center with a Large Vessel Occlusion

(LVO) stroke?

Is there a best prehospital scale to use?

Large Vessel Strokes

Internal Carotid and Middle Cerebral Strokes

• Hemiplegia on opp side

• Face and arm > leg

• Aphasia if dominate side

• Neglect

Vertebrobasilar & Posterior Circulation Strokes

• Acute vision loss

• Confusion

• N/V, dizzy, ataxia

• Headache

• Carotid Artery

• M1-M2 Middle Cerebral

• A1-A2 Anterior Cerebral

• Basilar or P1-P2 Posterior

• Intracranial Vertebral

Large Vessel Occlusion

J NeuroInterventional Surgery Online Feb 17, 2016

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School of Medicine: Case Western Reserve University

Why a comprehensive stroke center is so

important

• 500 patients from the Netherlands• Mechanical therapy vs control with TPA• 89% Rxd with TPA pre-randomization• Used retrievable stents (81.5%)

New Engl J Med 2014;372:11-20

Can a mechanical therapy improve outcome in CVA patients who have distal carotid or

proximal MCA or proximal ACA occlusion?

Business Medical Dialogues

All patients had distal internal carotid or proximal

MCA (M1, M2) or ACA (A1, A2) lesions

The Mr CLEAN Trial

New Engl J Med 2014;372:11-20

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Rankin Score

0 No symptoms

1 No clinically significant disability

2 Slight disabilities- - - - - - - - - - - - - - - - - - - - - - - - - -

3 Moderate disabilities

4 Moderately severe disabilities

5 Severe disabilities

6 Death0123456789

1011121314

6%

Modified Rankin Score 0 – 1 at 90 days0 = no sx, 1 no clinical disability

Control Group Mechanical Rx

11.6%

OR = 2.06(1.08 – 3.92)

New Engl J Med 2014;372:11-20

0

5

10

15

20

25

30

35

40

19.1%

Modified Rankin Score 0 – 2 at 90 days2 = slight disability, can look after self, not at baseline

Control Group Mechanical Rx

32.6%

OR = 2.05(1.36 – 3.09)

New Engl J Med 2014;372:11-20

There was a 13.5% absolute increase in the

likelihood of having a 0 – 2 modified Rankin

Score at 90 days

• Treatment within 4.5 hours of symptoms

• Internal Carotid or Proximal MCA occlusion

• Salvageable tissue on perfusion CTA

• Ischemic Core less than 70 ml

New Eng J Med 2015; 372: 1009-18

Does endovascular thrombectomy improve outcomes in acute stroke patients who are also

receiving TPA – The EXTEND-1A Trial

• Study stopped at 70 patients

• 14 Australian Centers

• Thrombectomy via Solitaire FR

• Median Time to Flow Restorer 210 min

New Eng J Med 2015; 372: 1009-18

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There was greater than 90% reperfusion

achieved in 89% of the Solataire FR Clot Retriever

+ TPA group vs a 34% with TPA alone

P < 0.001

There was a 31% absolute increase

(40% vs 71%) in the likelihood of having a

0 – 2 modified Rankin Score at 90 days

NNT= 3.2 for independent outcome

P = 0.001

Mechanical Device in StrokeTake Homes

Based now on multiple different

studies, t-PA plus mechanical therapy

is the standard of care.

How do you identify who to take to a center offering mechanical stroke therapy?

• Rapid Arterial Occlusion Evaluation (RACE) scale

• Designed based on NIH Stroke Scale (NIHSS)

• Face, Arm, Leg, Gaze, Aphasia, Agnosia

• Score is 0-9

Stroke 2014;45:87-91

Can a “simple” prehospital stroke scale predict large vessel occlusion (LVO) stroke?

RACE

Stroke 2014;45:87-91

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Stroke 2014;45:87-91

Results

• Correlation to NIHSS in retrospective trial: 93%

• Prospective trial:

- 357 pts

- RACE ≥ 5 = 85% sensitive, 68% specific

- The higher the RACE, the higher LVO %

RACE Sensitivity and Specificity

Stroke 2014;45:87-91

RACE Take Homes

• Great scoring system

• Hard to use unless aided

• Called a “simple tool” by authors

• Authors are from Stroke Program

• My bias: too hard for me to remember

“Available data does not allow a strong recommendation to be made…”

“Choice of the instrument depends on intended purpose and the consequences of a

false-negative or false positive result”

Emerg Med J 2016;33:818-22

7 different stroke instruments reviewed:

Prehosp Emerg Care 2018 Jan; ePub ahead of print

Can the Cincinnati Prehospital Stroke Scale reliably identify large vessel (LVO) strokes?

• 138 consecutively enrolled patients

• Used the well established CPSS

• Facial droop, arm drift, slurred speech

• 1 point each: 0-3 CPSS score

• Evaluated for LVO based on CPSS

• Carotid Artery

• M1-M2 Middle Cerebral

• A1-A2 Anterior Cerebral

• Basilar or P1-P2 Posterior

• Intracranial Vertebral

Large Vessel Occlusion

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0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

40%

74%

Specificity for Large Vessel Occlusion vs CPSS

Spec1

Spec2

Prehosp Emerg Care 2018 Jan; ePub ahead of print

88%

Spec3

Cincinnati Stroke Score & LVOTake Homes

• CPSS of 3: very good predictor of LVO

• If last well < 270 min + CPSS = 3then OR is 13.3 for LVO!

• Really easy to use (LAMS spec = 89%)

• CPSS 88% vs LAMS of 89%

• Already a part of many EMS systems

Stroke Scales & LVOTake Homes

• LVOs do better at major centers with mechanical devices

• We need to identify LVOs

• Use a scale you know and can routinely apply to R/O stroke patient

• Go to comprehensive center if available when close to other hospitals and/or if stroke older than 4.5 hours but under 12 hours