Pre-Hospital Management of Chest Pain Roll of the EMS System in Reducing Morbidity & Mortality from Acute Coronary Syndromes June 25, 2007 Andrew D. McGuire, BS, EMT-P EMS Coordinator Outline • Anatomy & Physiology • ACS Risk Factors • Pathology – Angina – Myocardial Infarction • DH ACS Protocol • 12-Lead ECG Thoracic Cavity Heart Walls and Chambers The Heart • Four Chamber Pump • Blood fed into RA • From RV to Lungs • Back to LA • To Body from LV through Aorta Coronary Arteries • Heart Muscle fed by Coronary Arteries • Originate from base of Aorta • LCA – LAD: Ant LV & septum – LCA: Post LV • RCA: RA & RV Electrical Impulses Physiology • Pump – Diastole – Atrial Systole – Ventricular Systole • Pressure – Starling’s Law Risk Factors • High blood Pressure • Diabetes • High Cholesterol • Immediate Family History (age < 55-60) • Smoking • Gender: Males > Females • Cocaine Use Atherosclerosis Pathology of Acute Coronary Syndrome (what is a heart attack, also called “ACS”) From the pre clinical phase to the acute phase of myocardial infarction From the AHA/ACC STEMI guidelines Pathology • Atherosclerosis • Thrombus/Emboli • Trauma • Spasm • Low/No Oxygen – Anemia – Hypotension – Drugs/toxins (CO, cocaine, opiates, cyanide) – Hypoxia Angina • Pathophysiology – Ischemia of heart muscle due to inadequate oxygen supply • Causes may include partial occlusion, spasm, hypotension and anemia – Transient in nature Angina • Stable: Onset during physical activity, lasting 3 to 5 minutes, relief with rest or self administered nitrates. • Unstable: Onset at rest, occurring more frequently, lasting > 5 minutes, resistance to nitrates. Angina • Signs and Symptoms – Chest Pain/ Pressure – Dyspnea – Diaphoresis – History is Essential Acute Coronary Syndrome / Myocardial Infarction ACS / Myocardial Infarction • Pathophysiology – Death and necrosis of heart muscle due to inadequate oxygen supply. • Causes may include occlusion, spasm, microemboli, acute volume overload, hypotension, acute respiratory failure, and trauma. – Location and size dependent on the vessel involved. ACS / Myocardial Infarction – Effects of a Myocardial Infarction • Dysrhythmias • Heart Failure – Goals of Treatment • Pain Relief • Reperfusion TIME = MUSCLE Prevalence of heart attack • Two types of heart attacks – STEMI – or ST elevation myocardial infarction – NSTEMI – or non-ST elevation myocardial infarction • 0.5 million STEMI’s a year in United States • About 100 per year at Danbury Hospital ED • Mortality from STEMI has been decreasing – Roll of public education – early presentation • Incidence of STEMI decreasing but NSTEMI increasing – Roll of public education – early presentation Prevalence of heart attack declining • Overall reduction from – Aggressive treatment of diabetes – Aggressive treatment of lipid disorders – Aggressive treatment of hypertension – Smoking cessation programs and public pressure for a smoke free environment Facts about ACS presentation • 30 percent of patients present with a lethal arrhythmia • 1 in 300 will fibrillate in the ambulance • Over 50% of acute myocardial infarctions DO NOT take an ambulance to the hospital – but chose to travel by private car instead • Taking an aspirin for symptoms has been associated with a delay in therapy – patients should be instructed to call 911 instead. • The average delay from symptoms to calling 911 is two hours Common Presenting Symptoms • Chest pressure or discomfort • Shoulder, neck, arm or jaw pain • Dyspnea • Syncope • Palpitations • Diaphoresis • Nausea • Anxiety Essential Elements of the History • Specific location of the chest pain (midsternal, etc.) • Radiation of pain, if present (e.g., to the jaw, back, or shoulders) • Duration of the pain • Factors that precipitated the pain (exercise, stress, etc.) • Type or quality of the pain (dull or sharp) • Pain scale (1-10) • Associated symptoms (nausea, dyspnea) • Anything that worsens, intensifies or alleviates the pain (including medications, moving or a deep breath) • Previous episodes of a similar pain (e.g., angina) Items of Immediate Assessment (<10 min) • Check vital signs • Determine oxygen saturation • Obtain 12-lead ECG (Paramedic) • Obtain a brief, targeted history and perform a physical examination Immediate General Treatment (AHA Guidelines) • Oxygen at 4 L/min • Aspirin 160 to 325 mg • IV of Normal Saline (EMT-I or P) • Nitroglycerin SL or spray (EMT-P) – EMT-B may assist with patients NTG • Morphine IV (if pain not relieved with nitroglycerin) (EMT-P) Oxygen Used in Acute Coronary Syndromes Why? • Increases supply of oxygen to ischemic tissue When? • Always when AMI is suspected How? • Start with nasal cannula at 4 L/min • Increase to NRB 10-15 LPM as needed Watch Out! • Rarely COPD patients with hypoxic ventilatory drive will hypoventilate • Administer O2 despite normal pulse-ox readings! Aspirin: Actions Why? (Actions) – Blocks formation of thromboxane A2 (thromboxane A2 causes platelets to aggregate and arteries to constrict) These actions will reduce – Overall mortality from AMI – Nonfatal reinfarction – Nonfatal stroke Aspirin • Mechanism of Action: Aspirin inhibits platelet aggregation, blocks pain impulses in the CNS. • Onset and Duration: Onset: 15 to 30 minutes Duration: 4 to 6 hours Aspirin: Indications, Dose, Precautions When? (Indications) As soon as possible! – Standard therapy for all patients with new pain suggestive of AMI – Give within minutes of arrival How? (Dose) (4) 81 mg tablets taken as soon as possible Watch Out! (Precautions) – Relatively contraindicated in patients with active peptic ulcer disease, asthma or on Coumadin therapy – Contraindicated in patients with known aspirin hypersensitivity – Bleeding disorders Pre-Hospital ACS Protocol 1. Primary BLS Level Care a. Initial assessment b. Oxygen, Vital signs, SpO2 monitoring 2. Aspirin (ASA): a. (4) 81 mg tabs Baby ASA PO b. Do not give ASA if the patient: i. Has a known allergy to ASA ii. Took 324 mg of ASA within last 8 Hours Pre-Hospital ACS Protocol If suspected STEMI/12-Lead ECG transmitted, identify the call to the ED as a “Cardiac Alert” – report to the ED physician (same as Trauma Alert protocol) Aspirin / Chest Pain Documentation of aspirin must be done by the EMT/EMT-I who administered it. The following must be documented on the PCR, in addition to the normal information and data: – Time and dose administered – Route of administration – EMT administering the ASA – Problems or complications (i.e. vomiting) – Response, if any, to the treatment – Vital signs after administration This data needs to be documented on the paramedic intercept PCR as well as the primary responder. Key Issue – the 12 lead ECG • A normal tracing does not preclude a heart attack • Use of primary angioplasty or thrombolytic therapy is restricted to patients with STEMI and typical symptoms of heart attack – Thus the 12 lead is critical for determining acute therapy – Obtaining a 12 lead electrocardiogram in the field and transmitting it to medical control reduces the time of delivery for urgent care 12 Lead ECG examples STEMI = 1 mm ST elevation in limb leads or 2 mm elevation in precordial leads limb leads precordial leads No acute changes – not STEMI could be NSTEMI STEMI = 1 mm ST elevation in limb leads or 2 mm elevation in precordial leads limb leads precordial leads Acute changes – Anterior STEMI STEMI = 1 mm ST elevation in limb leads or 2 mm elevation in precordial leads limb leads precordial leads Acute T wave changes – not STEMI could be NSTEMI STEMI = 1 mm ST elevation in limb leads or 2 mm elevation in precordial leads limb leads precordial leads Acute changes – Inferior STEMI STEMI = 1 mm ST elevation in limb leads or 2 mm elevation in precordial leads limb leads precordial leads Acute changes – Inferior STEMI ST Elevation in Leads II, III & aVF – Inferior Wall MI! In the treatment of Heart Attack the Goal is a Door to Balloon Time of less then 90 minutes • Each year, nearly 400,000 patients have ST- elevation myocardial infarction • Many patients are treated with emergency angioplasty • Recent national guidelines set a goal of door-to- balloon time of less than 90 minutes in 75 % of the time Where are we, where do we want to be, and what can we do to get there? From the AHA/ACC STEMI guidelines In the treatment of Heart Attack less time means lives saved Longer delay times means higher in hospital mortality. NRMI-2 data. from Cannon et al, JAMA 283(22); 2941 How the time is used to get to 90 minutes Seen by MD to Ready for complete care Transfer to Seen by MD Cath. Lab Pt arrives to Call back from EKG to MD then call placed ED to EKG to PAMD PAMD 30 minutes 15 minutes 5 minutes Cath Called by MD to All Cath Ready 30 minutes • Cath Team responds to call • Transportation between • Informed ED and Unit • Procedure Consent • Service Elevator Leaves ED to Stick to Balloon Cath Arrival to Patient Arrives Time Stick Time to Cath Lab 15 minutes 20 minutes 5 minutes How to shorten Door to Balloon Time – Remote ECG Transmission Seen by MD Pt arrives to Call back from EKG to MD then call placed ED to EKG to PAMD PAMD 15 minutes 5 minutes Danbury Hospital – Plans for therapy • Open Heart Surgery – available now • Primary Angioplasty – available now • Thrombolytic therapy – available now • Catheterization and treatment of NSTEMI – available now Danbury Hospital D2B time Q1 October-Decemeber 2005 vs. Q2 January-March 2006 100 D2B time 98 96 minutes 94 92 N= 15 pts N= 14 pts 90 88 Q1 Q2 12 Lead EKG taken in the field vs. not taken in the field Danbury Hospital Door to Balloon time 120 113 12 leads in field 12 lead Not obtained in the field 100 92 80 72 minutes 60 57 40 N=4 N=3 N=4 N=3 20 0 Q1 Q2 ECG transmission from the field saves time and lives in real life bulance EKG Transmission to ED Prior to Arrival 15% of all EKGs were transmitted from Oct 2005 to March 2007 3rdQ: 116.5 min. 103 min. 95.5 90 Minute goal 85 76.25 min. 30 minutes saved when ECG’s 56.5 transmitted from the field n=50 n=43 n=8 WalkIns A mb-No A mb-Yes Ambulance Transfer Ambulance Transfer EKG Transmission? No ECG transmission ECG transmission First 99 AMI treated at Danbury Summary • 50% of ACS patients still self-referring to the ED • Public education on role of 911 system still needed • More aggressive ASA administration by EMS • 12-Lead ECG & Transmit to the ED when STEMI identified • Patch in as a “Cardiac Alert” In a short period of time, we have demonstrated how our role in the pre-hospital setting is having a direct impact in the outcome (decreased morbidity & mortality) of ACS patients in the Greater Danbury Area.