Medical Emergencies: Neuro, Endocrine, Blood and Infection

In depth

The one-page summary above is what the PDF prints. These sections go further.

How this page fits with the others

This page covers the medical calls where the Paramedic decision turns on one cue: a meter that cannot be trusted, a pump with no insulin reserve, a fever that cannot wait, a seizure that is not a seizure, or weakness that will stop breathing. Glucose and seizure basics at EMT scope are on emt-by-complaint, the sepsis bundle on prehospital-sepsis and stroke scales and destinations on prehospital-stroke-stemi. Doses on the one-pager are NASEMSO National Model EMS Clinical Guidelines v3.0 (2022) unless named otherwise; local protocol rules.

Diabetes: meters, pumps and look-alikes

• HHS: Merck criteria are glucose 600 mg/dL or more, serum osmolality over 300 mOsm/kg and no significant ketosis; it follows a period of high glucose with too little fluid intake. NASEMSO warns that overly aggressive fluid can cause cerebral edema or dangerous hyponatremia, and that asymptomatic high glucose carries no field risk.
• DKA: NASEMSO lists abdominal pain, fruity breath and Kussmaul respirations, asks for a 12-lead to look for hyperkalemia and gives calcium, sodium bicarbonate and albuterol if it is found. A very low ETCO2 with a normal waveform and clear lungs is compensation for acidosis, not lung failure.
• Euglycemic DKA: a small share of DKA presents with glucose under 200 mg/dL. Pregnancy and SGLT2 inhibitors both lower the glucose at which DKA appears (Merck). In pregnancy, insulin resistance, a lower baseline bicarbonate and short fasts all favor ketosis, and untreated DKA carries a fetal death rate reported at 27-35% (Jaber 2019).
• Insulin pumps hold only rapid-acting insulin, so a kinked tube or dislodged cannula leaves no reserve and DKA can follow quickly (Khin 2026). NASEMSO lists a malfunctioning pump among the insulin causes of high glucose. In hospital an acutely ill patient has the pump removed, labeled and stored and starts IV insulin.
• Pump and low glucose (NASEMSO): stop or disconnect the pump if the patient cannot take oral glucose or ALS is not available; leave it running if oral glucose or ALS treatment can be given.
• CGM reads interstitial fluid, not capillary blood. Compression of the site, dehydration and edema widen the gap, and a capillary check is advised when symptoms do not match the sensor; capillary or venous values guide decisions (Khin 2026).
• Icodextrin (Extraneal) is broken down to maltose, which makes GDH-PQQ, glucose-dye-oxidoreductase and some GDH-FAD meters read falsely high for up to 2 weeks after it is stopped. The FDA label warns this has led to withheld treatment of hypoglycemia and to inappropriate insulin. Only glucose-specific methods are reliable.
• Beta blockers may prevent early warning signs of hypoglycemia such as tachycardia and raise the risk of severe or prolonged lows, especially in diabetes, children and fasting patients (metoprolol label).
• Late dumping is hyperinsulinemic hypoglycemia 1 to 3 hours after a carbohydrate-rich meal, driven mainly by an exaggerated GLP-1 response; about a third of patients in one bariatric cohort had such symptoms (Scarpellini 2020). Early dumping comes within the first hour and is mostly gastrointestinal and vasomotor.

Thyroid storm and myxedema coma

• Thyroid storm is triggered by infection, trauma, surgery, DKA or preeclampsia in an uncontrolled hyperthyroid patient. Merck lists fever, delirium or coma, vomiting, diarrhea, mild jaundice and tachycardia, and notes it can present as cardiovascular collapse and shock. The Japanese criteria use 38 °C and a heart rate of 130 or more; reported mortality is about 8% to over 30%.
• Field care: cooling, IV fluid and acetaminophen. Aspirin is avoided because it competes with thyroid hormone for protein binding and raises free T4 and T3 (Taylor 2026 joint consensus).
• Rate control: beta blockade can precipitate collapse, especially with systolic heart failure; in the Japanese survey, nonselective beta blockers given to patients in Killip class IV failure were linked to deaths. The tachycardia is partly a response to fever and volume loss. NASEMSO lists hyperthyroidism among the causes of tachycardia and says AF rarely needs field cardioversion. The hospital gives a beta blocker, propylthiouracil, iodine after the antithyroid drug, and hydrocortisone.
• Beta blockers can mask hyperthyroid tachycardia, and abrupt withdrawal of a beta blocker can precipitate thyroid storm (metoprolol label).
• Myxedema coma follows illness, infection, trauma, sedating drugs or cold exposure in hypothyroidism. Hypothermia can be missed without a low-reading thermometer; respiratory depression with CO2 retention is common. Rapid rewarming can cause hypotension or arrhythmias. The hospital gives large IV levothyroxine doses and glucocorticoids.

Sickle cell disease and hemophilia

• NASEMSO asks the crew to screen every sickle crisis for acute chest syndrome, stroke, meningitis, septic arthritis, splenic sequestration (young children: left upper pain, big spleen, shock), severe anemia, pneumonia, priapism and clots. Patients on regular opioids may need higher doses, and baseline anemia makes blood loss poorly tolerated.
• Acute chest syndrome is a new lung infiltrate with fever, chest pain, cough or hypoxia. CDC calls it a medical emergency for the hospital right away. Hospital care is oxygen, analgesia, antibiotics covering pneumococcus and atypical organisms, careful fluid at maintenance rates and transfusion (Ramirez 2026; Merck).
• Fever: chronic spleen damage leaves patients open to pneumococcal infection. CDC tells people with sickle cell disease to go to the ED or hospital for 38.5 °C or more, and notes fever may be the only sign of infection in a child. Merck adds that acutely ill patients with fever are admitted for cultures and IV antibiotics.
• Sickle cell stroke is treated with exchange transfusion, and chronic transfusion prevents recurrence (Merck), so the destination needs pediatric hematology and transfusion capability.
• Hemophilia A is factor VIII deficiency and hemophilia B factor IX. Bleeding goes into joints, muscles and the retroperitoneum, and even a trivial blow to the head can cause intracranial bleeding. Merck says treatment starts as soon as symptoms suggest bleeding, before tests are done, including factor before CT for a headache. Aspirin, NSAIDs and IM injections are avoided.

Neuromuscular respiratory failure and spine emergencies

• Guillain-Barre: ascending, fairly symmetric flaccid weakness with lost reflexes, starting 5 days to 3 weeks after a minor infection, surgery or vaccination. About 20% need intubation; the hospital intubates at a vital capacity under 15 mL/kg. Autonomic involvement brings BP swings and arrhythmias.
• Myasthenic crisis affects about 15-20% of patients at least once, often after infection, and respiratory failure may come rapidly once it starts. Aminoglycosides, quinine, magnesium sulfate, procainamide and calcium channel blockers can precipitate weakness. Too much pyridostigmine causes cholinergic crisis (fasciculations, tears, salivation, diarrhea). The hospital gives IVIG or plasma exchange.
• Botulism: symptoms start 18-36 hours after the toxin (range 4 hours to 8 days), symmetric and beginning with the cranial nerves, then descending; no sensory loss and no fever. Distress may not show as the paralysis deepens, even while vital capacity falls. CDC tells clinicians to call the state health department at once and not to wait for laboratory confirmation; Merck gives antitoxin as soon as the diagnosis is clinical.
• Tetanus: incubation 3-21 days, about 8 on average (CDC). Jaw stiffness is the most frequent complaint, and spasms are set off by drafts, noise or movement with a clear mind (Merck). Benzodiazepines are the standard for rigidity and spasms in a quiet room (Merck). Spasms can compromise the airway, and intubation or a tracheostomy with ventilation may be lifesaving (CDC). The hospital gives tetanus immune globulin, wound care and vaccination.
• Back pain red flags (NASEMSO): incontinence or retention, inability to walk from weakness, new limb deficits and saddle numbness point to cord or cauda equina compression from abscess, tumor or hematoma (anticoagulated patients). Injection drug use and immune compromise raise the risk of epidural abscess.
• Spinal epidural abscess (Merck): back pain and percussion tenderness become severe, fever is common, and leg weakness, saddle anesthesia and bladder or bowel dysfunction can follow within hours to days. Diagnosis is MRI; an abscess causing deficits is drained immediately, and delay until deficits appear worsens the outcome. Staphylococcus aureus is the usual organism.

Stroke causes and mimics

• NASEMSO stroke care: last known well with its source, glucose (treat only under 60 mg/dL), O2 to 94-98%, 12-lead if possible, early notification, head up 15-30 degrees if SBP is over 100, and no treatment of hypertension. In children treatment principles are the same, scales are not validated, and the crew calls ahead to confirm the hospital can manage a child.
• Cervical artery dissection causes 10-25% of strokes in young people. Head or neck pain on the side of the tear is the most frequent local sign, Horner syndrome (ptosis and miosis) appears in 28-58% of carotid dissections, and mild head or neck trauma is a reported trigger (Dejakum 2024).
• Cerebral venous thrombosis is more frequent in young women of reproductive age (female-to-male about 3:1 in low-income countries); oral contraceptives are present in 54-71%. Headache occurs in 70-90%, seizures in 30-40%, focal deficits in 30-50% and altered consciousness in 15-25%. Diagnosis is MR or CT venography and treatment is anticoagulation (Ranjan 2023).
• Pontine hemorrhage: intracerebral bleeds usually begin with a sudden headache, and posterior fossa bleeds cause stertorous breathing, pinpoint pupils and coma (Merck), a picture that resembles opioid toxicity. Naloxone that fails in a patient with a thunderclap onset should turn the crew toward a stroke center.
• Post-dural puncture headache usually starts 24-72 hours after the puncture, worsens upright and eases lying down, sometimes with tinnitus. Preeclampsia, eclampsia and cerebral venous thrombosis are the dangerous look-alikes. An epidural blood patch is the definitive treatment (Duran Monge 2026).
• Transient global amnesia (Merck): mean age 62; triggers include sudden cold or hot water immersion, exertion, emotional stress and sex. Patients repeat questions and are disoriented to time and place but keep their identity; the exam is otherwise normal. Episodes last a mean of 6 hours. Hippocampal stroke, transient epileptic amnesia and drug or toxin effects must be excluded with imaging, blood tests and EEG.
• Encephalitis (Merck): fever, headache and altered mental status, often with seizures or focal deficits; meningeal signs are typically mild. Olfactory seizures with foul smells suggest temporal lobe and herpes simplex involvement, and IV acyclovir is not withheld pending tests.
• Acute angle-closure glaucoma (Merck): severe eye pain and redness, blurred vision, colored halos, headache, nausea and vomiting, a fixed mid-dilated pupil and corneal edema; pressure is usually 40-80 mm Hg. Pupil dilation from dilating drops or anticholinergic drugs can start an attack. Treatment is immediate topical and systemic drugs, then laser iridotomy.

Seizure look-alikes

• Long QT: syncope from torsades can bring myoclonic jerks, and some patients are wrongly worked up for epilepsy. Triggers: exertion, especially swimming, or emotion (type 1); sudden loud noise such as an alarm clock (type 2); rest or sleep (type 3). An unexplained cardiac death in a relative under 30 counts toward the diagnosis (Merck). NASEMSO suggests a 12-lead after a seizure in a patient without a seizure history.
• Breath-holding spells start in the first year, peak at age 2 and are gone in almost all children by 8. In the cyanotic type the child cries, exhales, involuntarily does not inhale, turns blue and loses consciousness; a brief self-limited seizure can rarely occur. They do not raise the risk of epilepsy, and iron helps some children (Merck), so brief jerks in a typical spell do not call for an anticonvulsant. NASEMSO's BRUE guideline covers infants under 1 year only. Merck gives no rule for when to transport; the crew treats anything atypical (no trigger, during sleep, slow recovery, abnormal exam) as needing evaluation and transports it, and release of a typical spell with a normal exam to pediatric follow-up follows local protocol.
• Vagus nerve stimulator: a swipe of the magnet over the generator for less than 3 seconds gives an extra burst during a seizure; holding or taping the magnet over it stops stimulation, and normal operation resumes when it is removed (LivaNova). Standard seizure care still follows.

Infections that cannot wait

• Influenza (CDC): antivirals are recommended as soon as possible for anyone hospitalized, with severe or progressive illness or at higher risk of complications, with the greatest benefit within 48 hours; hospitalized patients still benefit later. Oseltamivir is the usual drug.
• Necrotizing soft-tissue infection: the early signs are severe pain out of proportion to the skin findings, swelling that reaches past the redness, and fever, with bullae, crepitus and necrosis later (WSES/SIS-E 2018). Diabetes is a major risk; mortality in treated patients is about 20-30%, and insufficient or late surgery is the most common error (Merck).
• Febrile infants: the AAP 2021 guideline covers well-appearing term infants 8-60 days old with 38.0 °C or more in three age bands (8-21, 22-28, 29-60 days). Serious bacterial infection in young infants often has no focal findings, comfort after an antipyretic does not mean a benign illness, and even low-risk infants 29-60 days have blood and urine cultures (Merck). NASEMSO: NSAIDs are contraindicated under 6 months.
• Septic arthritis (Merck): infants and children may show pseudoparalysis of a limb, irritability and feeding trouble, with high or low fever or none; bacterial arthritis can permanently damage the joint within hours to days, so it needs early drainage and IV antibiotics.
• Viral hemorrhagic fever (CDC EMS guidance): dispatch asks about risk factors and symptoms; one EMS clinician approaches and screens; personnel and procedures are limited to the essential; higher-level PPE for obvious bleeding, vomiting, diarrhea or instability; the receiving facility is notified in advance. The outer limit of incubation is 21 days for Ebola, Marburg, Lassa and South American fevers, and 14 days for Crimean-Congo.
• Malaria (Merck, CDC): falciparum incubation is 6-30 days; fever and chills in a returning traveler prompt immediate assessment. Cerebral malaria ranges from irritability to seizures and coma, hypoglycemia is common, and IV artesunate starts as soon as possible.
• Petechiae (RCH Melbourne): forceful coughing or vomiting can cause petechiae in the superior vena cava distribution above the nipples. Purpura are non-blanching spots over 2 mm. Rapid onset or progression of the rash, abnormal vital signs, shock or an altered conscious state mark the unwell child, who is treated for sepsis.

Exam traps

• Kussmaul breathing with a low ETCO2 and clear lungs: check glucose before any respiratory treatment.
• A normal glucose on a GDH-PQQ meter in an icodextrin patient does not rule out a low.
• A CGM low in a well patient with a normal fingerstick: believe the fingerstick.
• Pump patients have no long-acting insulin: a few hours without the pump can mean DKA.
• Thyroid storm fever: acetaminophen, never aspirin.
• Botulism and Guillain-Barre: SpO2 stays normal until late; watch ETCO2 and the breathing pattern.
• Tetanus spasms with a clear mind are not seizures.
• Hemophilia head bump: factor first, CT second.
• Sickle cell fever of 38.5 °C or more goes to the ED the same night.
• Febrile infant under 60 days goes in, however well the baby looks.
• Pinpoint pupils and coma after a thunderclap headache with no naloxone response: pontine bleed.