Prehospital STEMI Care

Prehospital STEMI CarePrehospital STEMI Care

BREMSS EMS ConferenceBREMSS EMS ConferenceJanuary 14-16, 2010January 14-16, 2010

DefinitionDefinition

ST-elevation Myocardial ST-elevation Myocardial InfarctionInfarction

ST SegmentST Segment

MyocardiumMyocardium

InfarctionInfarction

Irreversible tissue injury due to Irreversible tissue injury due to ischemia, or insufficient blood flow.ischemia, or insufficient blood flow.

Infarct

CausesCauses

Coronary Artery Coronary Artery Disease Disease (CAD)(CAD)

EmbolicEmbolic Coronary VasospasmCoronary Vasospasm Aortic DissectionAortic Dissection OtherOther

PathophysiologyPathophysiology

Typically results from Typically results from thrombosis (clot formation) of thrombosis (clot formation) of a coronary arterya coronary artery

Usually due to spontaneous Usually due to spontaneous rupture of a vulnerable rupture of a vulnerable atherosclerotic plaque.atherosclerotic plaque.

Coronary Thrombosis

Non-occlusive(non-STEMI)

Occlusive(STEMI)

PortraiPortrait of a t of a KillerKiller

How Does MI Kill?

VT/VF Cardiogenic Shock VSD, Cardiac Rupture Stroke CHF

Diagnosis: EKG

Characteristic changes Often changes on a minute-by

minute basis Initial tracing may not be

diagnostic Typical progression as time

passes

Firehats

Tombstones

Normal EKG

MIs Categorized by Location

Anterior Septal Lateral Inferior Combinations

Standard Lead Placement

Septal Anterior Lateral

Inferior Rhythm Strip

Anterior STEMI

Anteroseptal Infarct

Inferior MI

STEMI Mimics

Pericarditis Early Repolarization

Treatment: Reperfusion “Clot-buster”

Medications– AKA

thrombolytics, fibrinolytics

Angioplasty– AKA PTCA, PCI

Treatment Goals

Thrombolytics – 30 minutes from arrival to ED (Door to Needle)

PCI – 90 minutes from arrival(Door to Balloon; D2B)

NB: Non-EMS patients

Why PCI?

Lytics are– Widely available– Readily delivered– Cheaper– No radiation– No contrast (dye) exposure

But . . .

PCI results in– Less mortality– Less reinfarction / reocclusion– Less intracranial bleeding– Less recurrent ischemia

Also, 20% of patients are not eligible for thrombolysis.

Contraindications and Cautions for Fibrinolysis in ST ElevationMyocardial Infarction* Absolute contraindications

– Any prior ICH– Known structural cerebral vascular lesion (e.g., arteriovenous malformation)– Known malignant intracranial neoplasm (primary or metastatic)– Ischemic stroke within 3 months EXCEPT acute ischemic stroke within 3 hours– Suspected aortic dissection– Active bleeding or bleeding diathesis (excluding menses)– Significant closed-head or facial trauma within 3 months

Relative contraindications– History of chronic, severe, poorly controlled hypertension– Severe uncontrolled hypertension on presentation (SBP > 180 mm Hg or DBP > 110

mmHg)†– History of prior ischemic stroke greater than 3 months, dementia, or known

intracranial pathology not covered in contraindications– Traumatic or prolonged (greater than 10 minutes) CPR or major surgery (less than 3

weeks)– Recent (within 2-4 weeks) internal bleeding– Noncompressible vascular punctures– For streptokinase/ anistreplase: prior exposure (more than 5 days ago) or prior

allergic reaction to these agents– Pregnancy– Active peptic ulcer– Current use of anticoagulants: the higher the INR, the higher the risk of bleeding

ICH = intracranial hemorrhage; SBP = systolic blood pressure; DBP = diastolic blood pressure;CPR = cardiopulmonary resuscitation; INR = international normalized ratio; MI =myocardial infarction.

*Viewed as advisory for clinical decision making and may not be all-inclusive or definitive.†Could be an absolute contraindication in low-risk patients with MI (see Section 6.3.1.6.3.2).

2004 STEMI Guidelines

Why Are We Here?

When PCI capability is available, the best outcomes are achieved by offering this strategy 24 hours per day, 7 days per week. The systems goal should be a first medical contact–to-balloon time within 90 minutes.

Circulation, 1/2008: Focused STEMI Update

This Is A Tall Order

Note “medical contact” is defined as “time of EMS arrival on scene” after the patient calls EMS/9-1-1 or “time of arrival at the emergency department door” (whether PCI-capable or non–PCI-capable hospital) when the patient transports himself/herself to the hospital.

BREMSS Region

STEMI System Hospitals

Birmingham VAMC Brookwood Princeton BMC Shelby BMC St. Vincent’s St. Vincent’s East Trinity UAB

Receiving

Chilton Medical Center Cooper Green Mercy Lakeland Community

Hospital St. Vincent’s Blount St. Vincent’s St. Clair UAB Highlands UAB West Walker BMC

Referring

STEMI Chain of Reperfusion

Symptom onset Decision to seek medical attention Access medical system Arrive ED EKG Decision Notify cath lab Cath lab arrival Patient to cath lab PCI

Total Reperfusion Time

Scene Time 8 10

Transport Time 12 12

Door to EKG 5 -14

EKG to Decision 5 5

Decision to Cath Lab 30 30

Cath Lab/PCI Time 15 15

Total 75 58

Fundamental Equation

=

Minutes = Muscle

Obviously, even more time can be saved by diverting from a non-PCI-capable hospital to a PCI center.

Uncertain Risks

ConclusionConclusion