2.3 Protocol 10: Chest Pain & Protocol 19: Heart Problems / AICD
Key Takeaways
- Protocol 10 establishes a clinical age threshold of 35 years or older as an automatic baseline indicator of heightened acute coronary syndrome (ACS) risk.
- Atypical and silent myocardial infarctions—presenting as unexplained shortness of breath, sudden profound weakness, nausea, or cold sweats without chest pain—predominate in women, diabetics, and elderly patients.
- Clamminess (diaphoresis) in a patient with non-traumatic chest pain represents a priority symptom of hypoperfusion and cardiogenic compromise, elevating the call to a DELTA level.
- The MPDS Aspirin Diagnostic protocol guides administration of 160–325 mg of chewed aspirin only after systematically verifying the absence of allergy, active GI bleeding, stroke signs, recent trauma, or prior therapeutic dosing.
- Protocol 19 codes any A.I.C.D. discharge as 19-C-1 (CHARLIE) while the patient stays alert without priority symptoms, escalating to DELTA only on a finding such as not alert or clammy; dispatchers must assure callers that touching the patient during an internal discharge is completely safe.
Protocol 10: Chest Pain & Protocol 19: Heart Problems / AICD
Quick Answer: Protocol 10 (Chest Pain) and Protocol 19 (Heart Problems/AICD) govern suspected cardiac emergencies in conscious patients. In Protocol 10, patients aged 35 and older with chest pain, or patients exhibiting clamminess (cold sweats) or abnormal breathing, are triaged as high-acuity DELTA emergencies. EMDs must recognize atypical 'anginal equivalents' (nausea, isolated dyspnea, extreme weakness) prevalent in women and diabetics. The MPDS Aspirin Diagnostic screen allows dispatchers to instruct chewable aspirin (160–325 mg) after verifying zero contraindications. Protocol 19 handles dysrhythmias and internal defibrillators: an A.I.C.D. discharge is coded 19-C-1 (CHARLIE) while the patient is alert without priority symptoms, escalating to DELTA on findings such as not alert or clammy. Repeated firings still signal a possible electrical storm and must be relayed to responders, and the EMD reassures the caller that touching the patient is safe.
Pathophysiology of Acute Coronary Syndromes (ACS)
Cardiovascular disease remains the leading cause of global mortality. Acute Coronary Syndromes encompass a clinical spectrum ranging from unstable angina to non-ST-segment elevation myocardial infarction (NSTEMI) and catastrophic transmural ST-segment elevation myocardial infarction (STEMI). ACS results when an unstable atherosclerotic plaque within a coronary artery ruptures, triggering platelet aggregation and coronary thrombus formation. As myocardial cells are deprived of oxygen, cellular ischemia causes progressive necrosis, electrical instability, and lethal ventricular arrhythmias (VF/VT).
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| CORONARY ISCHEMIA TIME METRIC |
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| Myocardial necrosis begins: 20 minutes post-occlusion |
| Irreversible transmural death: 2-6 hours |
| Pre-hospital Aspirin Benefit: 23% reduction in vascular mortality |
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Because time-to-reperfusion ("door-to-balloon" or "door-to-needle" time) dictates patient survival, the EMD must rapidly identify ischemic symptoms, dispatch advanced life support resources, and execute pre-arrival antiplatelet protocols without delay.
Protocol 10: Structured Interrogation & Clinical Nuances
Protocol 10 is selected whenever a conscious patient complains of non-traumatic pain, pressure, heaviness, tightness, or discomfort anywhere between the navel and the jaw. The interrogation uncovers both classical and atypical presentations:
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| PROTOCOL 10 KEY QUESTION FOCUS |
| |
| 1. Age of patient (Threshold: >= 35 years standard risk) |
| 2. Breathing status (Normal vs. difficulty / shortness of breath) |
| 3. Perfusion / Diaphoresis ("Are they clammy, or have cold sweats?") |
| 4. Description of pain (Heaviness, squeezing, aching, crushing) |
| 5. Radiation (Left arm, right arm, jaw, neck, back, epigastrium) |
| 6. History of cardiac disease or prior heart attack |
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The Cardiac Age Threshold (Age ≥ 35)
The MPDS establishes 35 years of age as the standard threshold for cardiac risk stratification. Epidemiological data confirms that the incidence of coronary artery disease increases dramatically after age 35. Under Protocol 10:
- Any non-traumatic chest pain in a patient aged 35 or older automatically defaults to an elevated response level (CHARLIE or DELTA), even if the caller describes the pain as mild or musculoskeletal.
- In patients under age 35, chest pain without priority symptoms (normal breathing, dry skin, fully alert) is triaged at the ALPHA level, reflecting the overwhelming statistical likelihood of non-cardiac etiologies (costochondritis, pleurisy, thoracic muscle strain, or gastroesophageal reflux).
Classical vs. Atypical Presentations: The High-Risk Cohorts
Classical cardiac ischemia presents as dull, heavy, substernal crushing pressure—often described as "an elephant sitting on my chest"—radiating to the left shoulder, left arm, or jaw, accompanied by dyspnea and diaphoresis. However, the EMD must maintain extreme clinical vigilance for atypical presentations ("anginal equivalents"):
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| ATYPICAL CARDIAC PRESENTATIONS |
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| High-Risk Groups: Females, Diabetics, Geriatric Patients |
| Primary Symptoms: Shortness of breath, sudden profound fatigue, |
| nausea, vomiting, indigestion, dizziness |
| Underlying Cause: Autonomic neuropathy blunts visceral pain pathways|
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Up to 40% of women and over 50% of elderly diabetic patients suffering an acute myocardial infarction experience no central chest pain. Instead, autonomic neuropathy blunts visceral sensory pathways, causing the ischemic event to manifest purely as sudden dyspnea, overwhelming exhaustion, unexplained vomiting, or epigastric discomfort. When a female or diabetic patient calls complaining of sudden nausea, weakness, and cold sweats, the EMD must suspect ACS and process the call under cardiac protocols.
Priority Symptoms in Protocol 10: Clamminess
In the MPDS vernacular, clamminess (cold sweats / diaphoresis) is not merely an uncomfortable sensation—it is an ominous Priority Symptom. Profuse sweating in cardiac patients reflects massive sympathetic nervous system activation triggered by falling cardiac output and cardiogenic shock. The presence of clamminess in a chest pain patient instantly elevates the determinant code to 10-D-4 (Clammy or cold sweats), commanding an immediate DELTA-level Advanced Life Support response.
The MPDS Aspirin Diagnostic & Instruction Protocol
One of the most consequential clinical interventions an EMD can perform is the delivery of early antiplatelet therapy. Landmark clinical trials (including ISIS-2) demonstrated that early administration of chewable aspirin during an acute myocardial infarction reduces 35-day vascular mortality by 23%.
ASPIRIN MECHANISM OF ACTION:
Irreversibly inhibits platelet Cyclooxygenase-1 (COX-1),
blocking Thromboxane A2 production and halting coronary clot expansion.
The Five-Point Mandatory Contraindication Screening
Because aspirin permanently impairs platelet function for the 7-to-10 day lifespan of the cell, the EMD must rigorously execute the scripted Aspirin Diagnostic tool before authorizing administration. Every single question must be answered with a definitive "NO":
- Aspirin Allergy: "Are they allergic to aspirin?" (History of anaphylaxis, urticaria, or severe bronchospasm following aspirin or NSAIDs).
- Active Gastrointestinal Bleeding: "Have they had any bleeding in their stomach or bowels, or have they vomited blood or passed black, tarry stools?" (Prevents catastrophic exacerbation of active peptic ulcers).
- Stroke Symptoms: "Do they have any signs of a stroke, such as facial droop, arm weakness, or slurred speech?" (Aspirin administered during an acute hemorrhagic stroke is often fatal).
- Recent Major Trauma or Surgery: "Have they had any recent major surgery or head injury?"
- Prior Therapeutic Dosing: "Have they already taken a full dose of aspirin within the last 12 to 24 hours?"
Dosage and Administration Mechanics: The "Chew" Mandate
If the patient passes the diagnostic screen, the EMD instructs the caller:
"Give them 160 to 325 milligrams of aspirin. Instruct them to CHEW the tablets thoroughly before swallowing. Do NOT swallow them whole."
| Administration Form | Time to Peak Platelet Inhibition | Clinical Efficacy in AMI |
|---|---|---|
| Chewed Non-Enteric Aspirin | 5 to 15 minutes | Rapid buccal/gastric absorption halts thrombus |
| Swallowed Whole (Standard) | 60 to 90 minutes | Delayed gastric dissolution loses precious muscle |
| Swallowed Enteric-Coated | 3 to 4 hours | Ineffective for acute pre-hospital coronary occlusion |
Acceptable dosing options include one 325 mg adult non-coated tablet or two to four 81 mg low-dose baby aspirins (totaling 162–324 mg). Enteric-coated aspirin must also be chewed to destroy the acid-resistant polymer coating.
[!IMPORTANT] Parallel Dispatch Principle: Never delay emergency response dispatch to complete the Aspirin Diagnostic. Response units are dispatched in parallel during Case Entry or early Key Questions; aspirin coaching occurs during the pre-arrival phase while responders are en route.
Why EMDs Do Not Direct Nitroglycerin Administration
Callers frequently ask: "Should I give him his nitroglycerin pill?" Protocol standards strictly forbid EMDs from directing or advising nitroglycerin administration. Sublingual nitroglycerin causes profound venodilation. If administered to a patient with a Right Ventricular Infarction or someone who has consumed Phosphodiesterase-5 (PDE-5) inhibitors (e.g., sildenafil/Viagra within 24 hours, tadalafil/Cialis within 48 hours), nitroglycerin causes catastrophic, refractory hypotension and immediate cardiovascular collapse. Paramedics must obtain a 12-lead ECG and verify hemodynamic stability before administering nitrates.
Protocol 19: Heart Problems & Arrhythmias
Protocol 19 addresses conscious patients experiencing cardiac rhythm disturbances, including:
- Palpitations / Tachycardia: Sensation of racing, pounding, or fluttering heart rate ($> 100\text{ bpm}$). Sustained ventricular tachycardia can degenerate into ventricular fibrillation.
- Symptomatic Bradycardia: Heart rate below $60\text{ bpm}$ accompanied by lightheadedness, syncope, or hypotension.
Automated Implantable Cardioverter Defibrillators (AICD / ICD)
An AICD is an implanted electronic device that continuously monitors cardiac electrophysiology. When it detects ventricular tachycardia or ventricular fibrillation, it delivers an internal high-energy biphasic shock (typically 30 to 40 Joules) directly across the myocardium.
PROTOCOL 19: AICD TRIAGE
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Did the internal defibrillator fire?
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SINGLE SHOCK? MULTIPLE SHOCKS?
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CHARLIE (19-C-1) DELTA (19-D-1 .. 19-D-5)
"Firing of A.I.C.D." Priority symptom present:
Patient alert, breathing not alert, difficulty speaking
normally, no priority between breaths, changing
symptoms colour, clammy, or just
resuscitated / defibrillated
- Firing of the A.I.C.D. (19-C-1): The MPDS descriptor is simply "Firing of A.I.C.D." A patient who is alert, breathing normally, and free of priority symptoms is coded 19-C-1 (CHARLIE) whether the device fired once or several times.
- Escalation by Priority Symptom, Not by Shock Count: Repeated firing is a genuine clinical emergency — an electrical storm of refractory ventricular tachycardia/fibrillation, recurrent lethal dysrhythmias, or device malfunction — but in the MPDS the code escalates only when a priority symptom appears. The Protocol 19 DELTA descriptors are 19-D-1 Not alert, 19-D-2 Difficulty speaking between breaths, 19-D-3 Changing color, 19-D-4 Clammy or cold sweats, and 19-D-5 Just resuscitated and/or defibrillated (external). A patient shocked repeatedly who then turns pale, becomes clammy, or stops being alert moves to DELTA on that finding. Either way the EMD records the number of firings in the CAD narrative so responders arrive prepared for an electrical storm.
Bystander Safety: Overcoming the Fear of Electrical Shock
When an AICD fires, the sudden violent muscle jolt frequently terrifies bystanders. Callers often refuse to touch, comfort, or position the patient for fear of being electrocuted. The EMD must firmly deliver scripted reassurance:
"Listen to me: It is completely safe to touch the patient. An internal shock will not harm you."
Because the electrical circuit is completed internally between the defibrillator lead in the right ventricle and the device canister in the pectoral pocket, only an imperceptible micro-current can reach the patient's skin surface. Touching the patient poses zero electrical hazard to bystanders.
Comparative Matrix: Protocol 10 vs. Protocol 19 Clinical Pathways
| Assessment Category | Protocol 10: Chest Pain | Protocol 19: Heart Problems | Protocol 19: AICD Firing |
|---|---|---|---|
| Primary Clinical Focus | Suspected acute myocardial infarction | Dysrhythmia / palpitations | Internal defibrillator discharge |
| Critical Age Baseline | Age $\ge 35$ triggers CHARLIE/DELTA | Age $\ge 35$ elevates acuity | Device firing independent of age |
| Key Priority Symptom | Clamminess / cold sweats (10-D-4) | Sustained racing rate with syncope | A.I.C.D. firing (19-C-1); DELTA only on a priority symptom |
| Atypical Presentations | Dyspnea/nausea in women/diabetics | Silent runs of ventricular tach | Inappropriate firing / lead fracture |
| Pre-Arrival Medication | Aspirin Diagnostic (160–325 mg chewed) | No medications coached | No medications coached |
| Bystander Safety Role | Rest in position of comfort; no nitro | Rest quietly; monitor pulse | Reassure: touching patient is safe |
Aspirin Diagnostic Flowchart & Contraindication Matrix
| Screening Question | Clinical Rationale for Screening | Dispatcher Action if YES |
|---|---|---|
| 1. Aspirin Allergy? | Prevents life-threatening anaphylaxis or severe bronchospasm | WITHHOLD ASPIRIN |
| 2. Active GI Bleeding / Melena? | Prevents exacerbating lethal internal hemorrhagic ulceration | WITHHOLD ASPIRIN |
| 3. Signs of Stroke? | Prevents converting ischemic stroke or worsening intracranial bleed | WITHHOLD ASPIRIN |
| 4. Recent Trauma or Surgery? | Prevents fatal post-surgical or intracavitary hemorrhage | WITHHOLD ASPIRIN |
| 5. Full Dose in Past 12–24h? | Prevents salicylate toxicity without added therapeutic benefit | WITHHOLD ASPIRIN |
| ALL QUESTIONS ANSWERED NO | Patient is eligible for pre-hospital antiplatelet therapy | COACH 160–325 MG CHEWED |
Dispatch Dialogue: Interrogating Atypical Cardiac Chest Pain & Guiding Aspirin Administration
EMD: "9-1-1, what is the address of the emergency?"
CALLER: "712 Maple Grove Boulevard. My mother is really sick!"
EMD: "What is the phone number you're calling from?"
CALLER: "555-8834!"
EMD: "Tell me exactly what happened."
CALLER: "She's 62 years old and has diabetes. About thirty minutes ago, she started sweating like crazy, feeling dizzy, and throwing up!"
EMD: "Is she awake?"
CALLER: "Yes, she's awake on the sofa, but she looks awful."
EMD: "Is she breathing normally?"
CALLER: "She says she feels like she can't catch her breath."
EMD: "Is she complaining of any pain or discomfort between her belly button and her jaw?"
CALLER: "She says her upper stomach and jaw feel tight, but she says it's just indigestion."
EMD: "Are her hands or skin clammy or cold sweating?"
CALLER: "Yes, her shirt is soaking wet with cold sweat!"
EMD: [RECOGNIZES ATYPICAL ACS + CLAMMY -> CODES 10-D-4 -> SENDS ALS RESPONSE]
"Paramedics are being dispatched right now with lights and sirens. Stay on the line. I have some important medical questions."
EMD: "Is she allergic to aspirin?"
CALLER: "No, no allergies."
EMD: "Has she had any bleeding in her stomach or bowels, or vomited blood or passed black, tarry stools?"
CALLER: "No, nothing like that."
EMD: "Does she have any facial droop, arm weakness, or slurred speech?"
CALLER: "No, her speech is totally clear."
EMD: "Has she had any recent surgery or head injuries?"
CALLER: "No."
EMD: "Has she taken any aspirin in the last 24 hours?"
CALLER: "No, she hasn't taken anything."
EMD: "Do you have aspirin there right now?"
CALLER: "Yes, I have baby aspirins in the medicine cabinet!"
EMD: "Get them right now. Give her four low-dose baby aspirins, or one adult aspirin. Tell her to CHEW them thoroughly before swallowing. Chewing is very important to get the medicine into her blood quickly. Do not let her swallow them whole with water."
A 64-year-old female with insulin-dependent diabetes calls 911 complaining of sudden extreme weakness, severe nausea, lightheadedness, and drenching cold sweats that began 45 minutes ago. She denies any pain or pressure in her chest. How should the EMD interpret and process this call?
When screening a conscious 55-year-old chest pain patient for pre-arrival aspirin administration under MPDS, which of the following caller responses constitutes an absolute contraindication that requires withholding the medication?
A caller reports that her 68-year-old husband's internal defibrillator (AICD) has fired four times in the past fifteen minutes. He is conscious, alert, breathing normally and terrified, and his skin is warm and dry. What is the correct MPDS categorization and dispatcher safety advice?