3.4 Protocol 1: Abdominal Pain, Protocol 2: Allergies & Protocol 18: Headache

Protocols 1, 2, and 18: Abdominal Pain, Allergies, and Headache

Emergency medical dispatching often requires uncovering catastrophic, rapidly fatal systemic pathology masked by non-specific caller complaints. Protocols 1, 2, and 18 in the Medical Priority Dispatch System address chief complaints—abdominal discomfort, allergic reactions, and headaches—that can represent minor self-limiting conditions or fatal surgical and medical crises. Dispatchers must master the precise red flags and determinant logic that separate a benign condition from an immediate life threat.

1. Protocol 1: Abdominal Pain / Problems

Abdominal pain is one of the most frequent reasons for emergency medical dispatch. While many cases stem from benign gastroenteritis or constipation, the abdominal cavity houses major vascular structures and reproductive organs whose acute failure results in fatal internal exsanguination.

Occult Life Threats in Abdominal Pain

1. Ruptured Abdominal Aortic Aneurysm (AAA):

   • At-Risk Demographics: Males over the age of 50, especially with a history of hypertension, atherosclerosis, or smoking.
   • Clinical Presentation: Sudden, severe, tearing or ripping pain in the abdomen, flank, or lumbar back, frequently accompanied by syncope (fainting), profound hypotension, and a pulsatile mid-abdominal mass.
   • Acuity: Catastrophic vascular collapse; survival drops with every minute of delayed surgical intervention. In the MPDS, abdominal pain accompanied by fainting or near-fainting in a patient over 50 is coded 1-C-3 (CHARLIE), and a suspected or diagnosed aortic aneurysm is 1-C-1 / 1-C-2. Protocol 1's only DELTA codes are 1-D-1 Not alert and 1-D-2 Ashen or gray color reported (over 50) — so if the caller reports the patient is not alert or has turned ashen, the code moves to DELTA.

2. Ruptured Ectopic Pregnancy:

   • At-Risk Demographics: Any female in the biologically defined childbearing age range (12 to 50 years of age in MPDS standards).
   • Clinical Presentation: Acute lower abdominal, pelvic, or unilateral quadrant pain, accompanied by vaginal spotting or bleeding, dizziness, or syncope. When an ectopic pregnancy ruptures through the Fallopian tube, massive hemoperitoneum (bleeding into the peritoneal cavity) develops rapidly.
   • Acuity: A female aged 12 to 50 with abdominal pain and fainting or near-fainting is coded 1-C-4 (CHARLIE). The code is only CHARLIE, but the clinical implication is a surgical emergency: the EMD must flag the possible ruptured ectopic pregnancy to responders, and escalate to 1-D-1 (Not alert) or 1-D-2 (Ashen or gray color) the moment either appears.

3. Atypical Acute Myocardial Infarction (AMI):

   • In elderly patients, females, and individuals with long-standing diabetic autonomic neuropathy, myocardial ischemia frequently presents without classic crushing substernal chest pressure. Instead, it presents as isolated epigastric discomfort, "indigestion," nausea, diaphoresis, and unexplained weakness. If a patient over 35 presents with upper abdominal pain and clamminess or difficulty breathing, the EMD shunts or upgrades to cardiac triage under Protocol 10.

Protocol 1 Determinant Matrix

Protocol 1 has no ECHO and no BRAVO level. Its two DELTA codes turn on the patient's own condition (not alert, ashen or gray), while the demographic red flags for aortic aneurysm and ectopic pregnancy sit at CHARLIE.

2. Protocol 2: Allergies (Reactions) / Envenomations

Allergic reactions occur on a wide physiological spectrum, ranging from localized type I hypersensitivity reactions to life-threatening systemic anaphylaxis.

Localized Reaction vs. Systemic Anaphylaxis

Epinephrine Auto-Injector (EpiPen) Dispatch Life Support

When severe anaphylaxis is identified and the caller reports that an epinephrine auto-injector is present, the EMD must deliver immediate, scripted administration coaching:

1. Direct the caller to inspect the auto-injector: "Make sure the liquid inside is clear and not cloudy."
2. Instruct: "Grasp the injector in your fist. Never place your thumb over either end. Pull off the safety cap."
3. Position: "Hold the injector perpendicular (at a 90-degree angle) against the outer mid-thigh of the person's leg."
4. Deliver: "Push the tip firmly into the outer thigh until you hear or feel a click. Hold it firmly in place for a full count of 3 to 10 seconds (per device specification) to ensure all medication is injected."
5. Post-injection: "Remove the unit and massage the injection site for 10 seconds. Note the exact time of injection."
6. The Biphasic Risk: Callers must be advised that even if symptoms temporarily improve, field paramedics must evaluate the patient due to the risk of biphasic anaphylaxis, where severe airway edema and shock recur hours after epinephrine wears off.

3. Protocol 18: Headache

Headache complaints range from routine tension headaches and migraines to lethal intracranial catastrophes. The dispatcher's primary objective under Protocol 18 is screening for acute vascular rupture, intracranial space-occupying lesions, central nervous system infections, and acute ischemic cerebrovascular events.

The Red Flag Headache Presentations

1. Subarachnoid Hemorrhage (SAH) and the "Thunderclap" Headache:

   • Pathophysiology: Rupture of an intracranial arterial saccular (berry) aneurysm in the Circle of Willis, bleeding into the subarachnoid space under arterial pressure.
   • Cardinal Presentation: The classic thunderclap headache—an abrupt, explosive headache reaching maximum, unbearable intensity within seconds or minutes. Patients almost universally describe it as "the worst headache of my entire life."
   • Associated Signs: Immediate vomiting, photophobia, nuchal rigidity (neck stiffness), altered mental status, or sudden syncope.
   • Acuity: In the MPDS, a sudden onset of severe headache is coded 18-C-4 (CHARLIE). Protocol 18 has no DELTA and no ECHO level — CHARLIE is its highest determinant. If the patient stops breathing normally or becomes unresponsive, the EMD leaves Protocol 18 and re-triages on Protocol 31 or Protocol 9.

2. Acute Cerebrovascular Accident (Stroke / CVA):

   • Headache associated with unilateral facial droop, hemiparesis (arm or leg weakness), aphasia, dysarthria (slurred speech), or ataxia requires immediate prehospital stroke screening. Dispatchers must identify the exact time last known well and shunt or cross-triage to Protocol 28: Stroke / CVA.

3. Acute Bacterial Meningitis:

   • Severe headache accompanied by high fever, severe nuchal rigidity (inability to touch the chin to the chest), photophobia, and altered consciousness points to acute purulent bacterial meningitis. If a purpuric or petechial rash is present, invasive meningococcal disease (Neisseria meningitidis) is suspected, requiring ALS dispatch and immediate infectious disease scene precautions for field responders.

4. Carbon Monoxide (CO) Poisoning Cluster:

   • If a caller reports headache accompanied by nausea and dizziness affecting two or more individuals within the same dwelling or structure, the dispatcher must instantly recognize an environmental hazard. The call must shunt to Protocol 8: Carbon Monoxide / Hazmat, directing immediate evacuation into fresh outdoor air.

Protocol 18 Determinant Hierarchy

Protocol 18 tops out at CHARLIE. Its seven CHARLIE descriptors are the heart of the protocol:

Like Protocol 28, Protocol 18 carries a stroke-evidence suffix recording the result of the Stroke Diagnostic tool (no test evidence, partial, strong, or clear evidence) together with the time since symptoms started (under 2 hours, over 2 hours, or unknown).

4. Cross-Protocol Comparison of Red Flag Emergencies

To ensure flawless decision-making during fast-paced triage, dispatchers must cross-reference key demographic indicators, pathophysiological markers, and mandatory determinant coding across these acute medical protocols.