Most likely diagnosis: Undifferentiated shock, with septic shock high in the differential. Differential diagnosis • Sepsis • Acute coronary syndrome • Pulmonary embolism • Internal hemorrhage • Anaphylaxis • Adrenal crisis • Severe hypoglycemia • Toxic ingestion Immediate management 1. Activate EMS. 2. Assess and maintain the airway. 3. Administer oxygen when indicated. 4. Apply cardiac, oxygen-saturation and blood-pressure monitoring. 5. Obtain point-of-care glucose. 6. Establish IV access when trained and authorized. 7. Reassess continuously. Botanical and nutritional considerations: No botanical medicine, supplement or oral fluid should delay stabilization or emergency transport. Clinical pearl: A patient can be in shock before profound hypotension develops. NPLEX trap: Do not complete a lengthy history or examination before treating immediate ABC abnormalities.

Diagnosis: Severe foreign-body airway obstruction. Key signs • Inability to speak • Weak or absent cough • Cyanosis • Altered consciousness • Apnea Immediate treatment • Activate the emergency-response system. • Alternate five back blows and five abdominal thrusts. • Use chest thrusts in late pregnancy or when abdominal thrusts cannot be performed. • If unresponsive, start CPR and attach an AED. • Remove only a visible object. Clinical pearl: A patient who is coughing forcefully should usually be encouraged to continue coughing while being closely monitored. NPLEX trap: Do not perform blind finger sweeps.

Diagnosis: Acute severe asthma exacerbation. Differential diagnosis • Anaphylaxis • Foreign-body aspiration • Pulmonary embolism • Pneumothorax • Vocal-cord dysfunction • Acute heart failure Immediate treatment • Activate EMS for severe or life-threatening features. • Administer inhaled rapid-acting bronchodilator. • Add inhaled ipratropium in severe disease. • Give controlled oxygen when hypoxemic. • Administer an early systemic corticosteroid. • Monitor respiratory effort, oxygen saturation, mental status and peak flow when feasible. Pharmacology safety: Excessive beta₂-agonist exposure can cause tremor, tachycardia and hypokalemia, but necessary emergency bronchodilation should not be withheld. Botanical safety: Lobelia, ephedra, essential oils and sedating herbs are not substitutes for emergency bronchodilator and corticosteroid treatment. Clinical pearl: Less wheezing in a deteriorating patient may mean less airflow, not improvement. NPLEX trap: Never interpret a silent chest as resolution of bronchospasm.

Diagnosis: Anaphylaxis with shock. Immediate management 1. Stop exposure to the suspected trigger. 2. Activate EMS. 3. Administer IM epinephrine promptly. 4. Position the patient safely; avoid sudden standing. 5. Provide oxygen and airway support. 6. Establish IV access when authorized. 7. Give isotonic crystalloid for significant hypotension. 8. Repeat IM epinephrine every five minutes if severe symptoms persist. 9. Arrange emergency observation because symptoms can recur. Differential diagnosis • Vasovagal syncope • Acute asthma • Panic attack • Hereditary angioedema • Cardiogenic shock Pharmacology safety: Incorrect use of the 0.1 mg/mL IV cardiac-arrest preparation instead of 1 mg/mL IM epinephrine can cause a dangerous dosing error. Botanical safety: Injectable botanicals can cause severe hypersensitivity. Stop all suspected products and document the reaction. Clinical pearl: Anaphylaxis can occur without hives. NPLEX trap: Do not delay epinephrine while establishing IV access or administering antihistamines.

Diagnosis: Opioid poisoning with respiratory failure. Immediate management • Verify scene safety and use appropriate PPE. • Activate EMS. • Open the airway. • Provide effective ventilations and oxygen. • Administer naloxone. • Start CPR and use an AED if pulseless. • Reassess continuously. • Arrange emergency monitoring after initial reversal. Differential diagnosis • Hypoglycemia • Stroke • Sedative-hypnotic overdose • Head trauma • Carbon-monoxide exposure • Postictal state Pharmacology safety: Naloxone can precipitate acute withdrawal, agitation, vomiting and sympathetic activation, but respiratory rescue remains the priority. Botanical safety: No stimulant herb or essential oil is an appropriate substitute for ventilation and naloxone. Clinical pearl: Treat the respiratory depression, not merely the pupil size. NPLEX trap: Naloxone must never delay ventilation, CPR or AED use.

Diagnosis: Septic shock, likely secondary to pyelonephritis. Key investigations in hospital • CBC • Electrolytes and renal function • Serum lactate • Blood cultures • Urinalysis and urine culture • Glucose • Liver tests • Appropriate imaging for obstruction or another source • ECG and cardiac monitoring when indicated Hospital-level treatment • Immediate resuscitation • Crystalloid fluid with frequent reassessment • Prompt empiric antimicrobial therapy • Source identification and control • Norepinephrine for persistent shock • Serial perfusion and lactate assessment Botanical and nutrition safety: Cranberry, uva ursi, berberine, vitamin C and other natural products must not delay sepsis treatment. Current sepsis guidance suggests against IV vitamin C as a sepsis therapy. Clinical pearl: Confusion may be the presenting feature of sepsis in an older adult. NPLEX trap: Do not manage hypotensive pyelonephritis as an uncomplicated outpatient urinary infection.

Diagnosis: Sudden cardiac arrest, likely related to acute coronary syndrome. Shockable rhythms • Ventricular fibrillation • Pulseless ventricular tachycardia Nonshockable rhythms • Asystole • Pulseless electrical activity Immediate management • Recognize cardiac arrest. • Activate EMS. • Begin high-quality CPR. • Attach and use an AED rapidly. • Minimize pauses in compressions. • Provide appropriate ventilations. • Continue until advanced care assumes management or the patient clearly recovers. Pharmacology safety: Oral aspirin is inappropriate during unconsciousness and must never delay CPR. Clinical pearl: The AED determines whether the rhythm is shockable; the rescuer should follow its prompts. NPLEX trap: Agonal gasping is not adequate breathing.

Diagnosis: Severe insulin-associated hypoglycemia. Symptoms • Sweating • Tremor • Palpitations • Hunger • Behavioural change • Confusion • Seizure • Loss of consciousness Treatment • Assess airway and breathing. • Check glucose promptly. • If conscious and able to swallow, give rapid oral carbohydrate. • If unconscious, use IV dextrose or glucagon. • Recheck glucose. • Provide longer-acting carbohydrate after recovery when appropriate. • Investigate the medication, meal, activity, alcohol and renal-function history. • Arrange emergency assessment for prolonged, recurrent or unexplained episodes. Botanical safety: Glucose-lowering supplements can compound medication-associated hypoglycemia. Clinical pearl: A confused patient with diabetes should be considered hypoglycemic until glucose is checked. NPLEX trap: Never give oral treatment to a patient unable to protect the airway.

Diagnosis: Acute stroke syndrome. B.E. F.A.S.T. warning signs • B: Sudden balance loss • E: Sudden eye or vision change • F: Facial droop • A: Arm weakness • S: Speech difficulty • T: Time to call EMS Immediate management • Activate EMS. • Document last-known-well time. • Assess ABCs. • Check glucose. • Keep the patient NPO. • Monitor neurologic and vital-sign changes. • Do not aggressively lower blood pressure without an appropriate emergency indication and protocol. • Do not give aspirin until hemorrhage has been excluded. Differential diagnosis • Hypoglycemia • Seizure with postictal weakness • Migraine with aura • Bell palsy • Intracranial mass • Functional neurologic disorder Botanical safety: Ginkgo, garlic and other products with antiplatelet effects should not be given during an undifferentiated acute stroke. Clinical pearl: “Time last known well” may differ from the time the patient was discovered symptomatic. NPLEX trap: Improvement or disappearance of symptoms does not eliminate the need for emergency assessment.

Diagnosis: Exertional heat stroke. Key diagnostic feature: Hyperthermia plus altered central nervous system function. Immediate treatment • Activate EMS. • Move the patient away from the heat. • Remove excess clothing. • Begin rapid active cooling immediately. • Maintain airway and ventilation. • Monitor circulation and mental status. • Establish IV access when authorized. • Avoid oral fluids in a confused patient. • Transfer for assessment of renal, hepatic, electrolyte, coagulation and muscle injury. Differential diagnosis • Severe hyponatremia • Hypoglycemia • Seizure • Intracranial hemorrhage • Sympathomimetic toxicity • Serotonin syndrome • Neuroleptic malignant syndrome Pharmacology safety: Antipyretics do not treat the underlying mechanism of heat stroke. Clinical pearl: Sweating may still be present in exertional heat stroke; dry skin is not required for diagnosis. NPLEX trap: Do not delay cooling while waiting for EMS or laboratory confirmation.

Most likely diagnosis: Acute upper gastrointestinal hemorrhage causing hypovolemic shock. Differential diagnosis • Bleeding peptic ulcer • Esophageal or gastric varices • Mallory–Weiss tear • Gastric malignancy • Dieulafoy lesion • Swallowed upper-airway blood • Aortoenteric fistula in a high-risk patient Immediate stabilization 1. Activate EMS. 2. Assess airway protection. 3. Give oxygen when hypoxemic or clinically indicated. 4. Position safely and prepare suction. 5. Obtain cardiac and blood-pressure monitoring. 6. Establish large-bore IV access when authorized. 7. Keep the patient warm. 8. Keep the patient NPO. 9. Communicate medication and bleeding history. 10.Reassess continuously. Key hospital investigations • CBC • Electrolytes and renal function • Coagulation studies • Type and crossmatch • Liver tests • Lactate • ECG when indicated • Urgent endoscopy after stabilization Botanical and supplement safety: Ginkgo, high-dose garlic, dong quai and other products with potential antiplatelet effects should be documented, but obtaining an extensive supplement history must not delay transport. Clinical pearl: A normal early hemoglobin level does not exclude major acute hemorrhage because whole blood is initially lost proportionately. NPLEX trap: Do not give oral fluids to a hypotensive patient with active gastrointestinal bleeding.

Diagnosis: Acute myocardial infarction complicated by cardiogenic shock and pulmonary edema. Differential diagnosis • Mechanical complication of myocardial infarction • Acute severe mitral regurgitation • Ventricular septal rupture • Acute myocarditis • Massive pulmonary embolism • Cardiac tamponade • Aortic dissection • Severe tachyarrhythmia or bradyarrhythmia Immediate stabilization • Activate EMS. • Maintain the airway. • Give oxygen for hypoxemia. • Assist ventilation when required. • Attach cardiac and defibrillation monitoring. • Obtain a 12-lead ECG without delaying transport. • Establish IV access when authorized. • Avoid routine large fluid boluses. • Prepare for cardiac arrest. Definitive management: Hospital treatment may include urgent coronary angiography and revascularization, vasopressor or inotropic support, mechanical circulatory support and treatment of mechanical complications. The 2025 ACS guideline covers emergency management of STEMI, NSTEMI and unstable angina, including invasive management of myocardial infarction complicated by cardiogenic shock. Botanical safety: Hawthorn, coenzyme Q10 or other cardiovascular supplements have no role in acute cardiogenic shock. Clinical pearl: Cardiogenic shock can present with both systemic hypoperfusion and pulmonary fluid overload. NPLEX trap: Do not automatically administer a large crystalloid bolus to every hypotensive patient.

Working diagnosis: Acute coronary syndrome. Possible forms • STEMI • NSTEMI • Unstable angina Immediate management • Activate EMS. • Stop activity and position comfortably. • Assess ABCs. • Attach cardiac monitoring and obtain an ECG when available. • Give aspirin when appropriate under protocol. • Give oxygen only when hypoxemic or in respiratory distress. • Consider nitroglycerin only when blood pressure and medication history permit. • Prepare for arrhythmia or cardiac arrest. Differential diagnosis • Aortic dissection • Pulmonary embolism • Pneumothorax • Pericarditis • Esophageal rupture • Gastroesophageal reflux • Musculoskeletal pain • Panic attack Clinical pearl: Women, older adults and patients with diabetes may present with dyspnea, nausea, weakness or epigastric discomfort rather than classic chest pain. NPLEX trap: Never dismiss potentially ischemic chest discomfort as anxiety before excluding a dangerous cardiovascular cause.

Diagnosis: Hemodynamically unstable regular narrow-complex tachyarrhythmia. Potential rhythms • Supraventricular tachycardia • Atrial flutter with fixed conduction • Atrial tachycardia • Less commonly, another regular narrow-complex rhythm Immediate management 1. Activate EMS or the resuscitation team. 2. Maintain the airway and assist breathing. 3. Give oxygen if hypoxemic. 4. Apply cardiac, blood-pressure and oxygen-saturation monitoring. 5. Establish IV access. 6. Perform synchronized cardioversion. 7. Sedate when feasible without delaying emergency treatment. 8. Reassess after each intervention. Adenosine: It may be considered for a regular narrow-complex tachycardia and, in selected circumstances, a regular monomorphic wide-complex rhythm. It should not delay synchronized cardioversion when the patient is unstable. Clinical pearl: Treat the patient’s perfusion status, not merely the heart-rate number. NPLEX trap: An unstable tachyarrhythmia with a pulse requires synchronized cardioversion—not routine outpatient medication adjustment.

Diagnosis: Unstable symptomatic bradycardia due to high-grade atrioventricular block. Immediate management • Activate EMS. • Maintain airway and breathing. • Give oxygen when hypoxemic. • Attach cardiorespiratory monitoring. • Obtain IV access. • Administer atropine under protocol. • Prepare transcutaneous pacing early. • Consider dopamine or epinephrine infusion if atropine is ineffective. • Investigate and treat reversible causes. Medication causes • Beta-blockers • Non-dihydropyridine calcium-channel blockers • Digoxin • Amiodarone • Certain antiarrhythmics • Cholinergic agents Clinical pearl: High-grade atrioventricular block may respond poorly to atropine, so pacing equipment should be prepared promptly. NPLEX trap: Do not delay pacing in a deteriorating patient while repeatedly attempting ineffective medication treatment.

Diagnosis: High-risk pulmonary embolism with obstructive shock. Differential diagnosis • Acute myocardial infarction • Cardiac tamponade • Tension pneumothorax • Aortic dissection • Severe pneumonia • Acute asthma • Fat embolism Immediate stabilization • Activate EMS. • Provide oxygen and ventilatory support. • Apply cardiac and oxygen-saturation monitoring. • Obtain IV access. • Avoid delaying transport for outpatient investigations. • Prepare for pulseless electrical activity arrest. • Use fluid cautiously because excessive volume may worsen right-ventricular strain. Clinical pearl: Distended neck veins with shock and relatively clear lungs suggest an obstructive process such as pulmonary embolism, tamponade or tension pneumothorax. NPLEX trap: Do not rely on a D-dimer to manage a hemodynamically unstable patient.

Diagnosis: Traumatic tension pneumothorax. Immediate management • Activate EMS. • Administer high-concentration oxygen. • Support airway and ventilation. • Perform emergency decompression when properly trained and authorized. • Arrange definitive chest-tube management in the emergency department. • Monitor continuously. • Assess for other traumatic injuries. Differential diagnosis • Massive hemothorax • Cardiac tamponade • Open pneumothorax • Flail chest • Pulmonary contusion • Traumatic diaphragmatic rupture Clinical pearl: Hypotension plus unilateral absent breath sounds after trauma is tension pneumothorax until proven otherwise. NPLEX trap: Never delay lifesaving decompression to obtain radiographic confirmation in an unstable patient.

Diagnosis: Cardiac tamponade causing obstructive shock. Potential causes • Cardiac procedure complication • Penetrating or blunt trauma • Malignancy • Uremia • Pericarditis • Aortic dissection • Anticoagulant-associated bleeding Immediate stabilization • Activate EMS. • Maintain airway and oxygenation. • Apply cardiac and blood-pressure monitoring. • Obtain IV access. • Prepare for cardiac arrest. • Arrange urgent bedside echocardiography and pericardial drainage. • Avoid interventions that markedly reduce preload. Clinical pearl: Beck triad may be incomplete; point-of-care echocardiography is valuable, but an unstable patient must be treated without unnecessary delay. NPLEX trap: Diuretics and vasodilators can worsen tamponade by further reducing cardiac filling.

Diagnosis: SGLT2 inhibitor-associated euglycemic diabetic ketoacidosis. Precipitating factors • Acute infection • Vomiting or dehydration • Fasting or very-low-carbohydrate intake • Surgery • Missed insulin • Excessive alcohol intake • Pregnancy • SGLT2 inhibitor use Key investigations • Serum beta-hydroxybutyrate • Venous or arterial blood gas • Electrolytes • Anion gap • Glucose • Renal function • Magnesium and phosphate when indicated • ECG • Infection evaluation Hospital treatment • IV crystalloid • IV insulin • Potassium-guided electrolyte management • Dextrose as glucose falls so insulin can continue until ketoacidosis resolves • Treatment of the precipitating cause • Close glucose, electrolyte and acid–base monitoring The ADA identifies fluid replacement, insulin, electrolyte correction and treatment of the precipitating event as the main elements of DKA and HHS management. Botanical and nutrition safety: Do not treat DKA with oral electrolyte products, cinnamon, berberine or fasting. A ketogenic diet may complicate risk assessment in a susceptible patient. Clinical pearl: A relatively normal glucose level does not exclude DKA in a patient taking an SGLT2 inhibitor. NPLEX trap: Do not stop insulin simply because the glucose is not severely elevated.

Diagnosis: Life-threatening hyperkalemia with cardiotoxicity. Possible causes • Acute or chronic kidney failure • ACE inhibitor or ARB • Potassium-sparing diuretic • Potassium supplements • Acidosis • Tissue breakdown • Insulin deficiency • Adrenal insufficiency • Trimethoprim • NSAID use Emergency treatment framework 1. Activate EMS or the resuscitation team. 2. Apply continuous cardiac monitoring. 3. Stabilize the myocardium with IV calcium when indicated. 4. Shift potassium intracellularly with insulin-glucose. 5. Consider nebulized beta₂-agonist as an adjunct. 6. Remove potassium through appropriate binders, diuresis or dialysis. 7. Identify and treat the cause. 8. Recheck potassium, ECG and glucose repeatedly. Medication safety: Insulin-glucose therapy can cause delayed hypoglycemia, especially in patients with kidney failure, lower baseline glucose, older age or low body weight. Botanical safety: Potassium-containing salt substitutes and supplements must be identified. Natural diuretics are not appropriate emergency potassium-removal treatments. Clinical pearl: The severity of ECG abnormalities does not always correlate perfectly with the potassium level; treat the entire clinical presentation. NPLEX trap: IV calcium protects the heart temporarily but does not lower total-body potassium.

Diagnosis: Potentially toxic acute acetaminophen ingestion. Important investigations • Acetaminophen concentration • AST and ALT • INR • Bilirubin • Creatinine and urea • Electrolytes • Blood glucose • Pregnancy testing when applicable • Testing for suspected co-ingestants These investigations assess exposure severity and hepatic, renal and metabolic complications. Rumack–Matthew nomogram: It applies to a single acute ingestion with a reasonably known time. It is not reliable for an unknown time, repeated supratherapeutic ingestion or a clearly staggered overdose. Activated charcoal: It may be considered in selected recent ingestions when recommended by a toxicologist and when the airway is protected. Patients should not attempt charcoal treatment at home. Botanical safety: Milk thistle and other purported liver-support products are not substitutes for N-acetylcysteine. Clinical pearl: Serious acetaminophen toxicity may be clinically silent during the first several hours. NPLEX trap: Do not wait for elevated liver enzymes or jaundice before initiating appropriate overdose management.

Diagnosis: Acute salicylate toxicity. Key investigations • Serial salicylate concentrations • Blood gas • Electrolytes and anion gap • Potassium • Glucose • Renal function • ECG • Chest imaging when pulmonary edema is suspected A single salicylate level must not be interpreted without the ingestion history, acid–base status and clinical trajectory. Emergency management • Activate EMS and consult the Poison Centre. • Stabilize airway, breathing and circulation. • Correct volume depletion. • Maintain serum alkalemia and alkalinize urine with IV sodium bicarbonate. • Correct hypokalemia because low potassium impairs urinary alkalinization. • Give glucose when clinically indicated, even when serum glucose appears normal. • Consider activated charcoal only in selected cases with an adequately protected airway. • Arrange early hemodialysis assessment for severe toxicity. These priorities are outlined by the American College of Medical Toxicology. Indications suggesting dialysis: Severe neurologic manifestations, pulmonary edema, kidney failure, worsening acidemia, clinical deterioration despite alkalinization or very high concentrations can warrant urgent extracorporeal removal. NPLEX trap: A decreasing salicylate concentration does not prove improvement if the patient is becoming acidemic or neurologically worse.

Diagnosis: Severe tricyclic antidepressant poisoning with anticholinergic findings, hypotension and sodium-channel cardiotoxicity. Clinical manifestations • Agitation, delirium or coma • Mydriasis • Dry skin and mucosa • Urinary retention • Tachycardia • Hypotension • QRS widening • Ventricular arrhythmia • Seizures The combination reflects antimuscarinic, alpha-adrenergic and cardiac ion-channel effects. Emergency management • Activate EMS and contact the Poison Centre. • Stabilize airway and breathing. • Obtain continuous ECG monitoring. • Establish IV access. • Give sodium bicarbonate for hypotension, QRS widening or ventricular dysrhythmia. • Treat seizures with benzodiazepines. • Use vasopressors when hypotension persists despite appropriate bicarbonate and supportive therapy. • Consider extracorporeal life support in refractory cardiogenic shock at an equipped centre. The AHA considers extracorporeal support reasonable for poisoning-related refractory shock or cardiac arrest when pharmacologic measures fail. Clinical pearl: The ECG is one of the most valuable early tests in suspected tricyclic antidepressant poisoning. NPLEX trap: Do not select physostigmine merely because the patient appears anticholinergic when the QRS is widened.

Diagnosis: Life-threatening cocaine-associated sympathomimetic poisoning with hyperthermia, hypertensive emergency, chest pain and sodium-channel toxicity. Emergency management • Activate EMS. • Provide benzodiazepine-based sedation. • Begin immediate active cooling. • Assess glucose and electrolytes. • Obtain continuous ECG monitoring. • Treat coronary vasospasm or hypertensive emergency with appropriate vasodilators under advanced-care protocols. • Treat wide-QRS toxicity with sodium bicarbonate. • Manage seizures promptly. • Evaluate for acute coronary syndrome, aortic injury, rhabdomyolysis, kidney injury and intracranial hemorrhage. These treatments align with the AHA’s 2025 recommendations for life-threatening cocaine and sympathomimetic poisoning. Restraint safety: Temporary restraint may sometimes be needed for immediate safety, but prolonged physical restraint without effective sedation is potentially harmful and may worsen hyperthermia and acidosis. Beta-blocker trap: AHA guidance does not recommend beta-adrenergic antagonists for acute cocaine-induced coronary vasospasm or hypertensive emergencies because of uncertain benefit and possible harm. NPLEX trap: Do not treat stimulant hyperthermia as ordinary fever with acetaminophen.

Diagnosis: Severe organophosphate poisoning with cholinergic crisis and impending respiratory failure. Emergency management 1. Protect rescuers with PPE. 2. Remove the patient from exposure. 3. Remove contaminated clothing and isolate it appropriately. 4. Perform dermal decontamination. 5. Suction secretions and support ventilation. 6. Administer atropine immediately. 7. Administer pralidoxime for organophosphate poisoning. 8. Treat seizures or severe agitation with benzodiazepines. 9. Arrange early advanced-airway management. 10.Activate EMS and consult the Poison Centre. These interventions are directly supported by the AHA special-circumstances guidance. Medication safety: Succinylcholine and mivacurium depend on cholinesterase metabolism and are not recommended because paralysis may be markedly prolonged. Clinical pearl: Atropine improves muscarinic manifestations but does not reliably reverse skeletal-muscle paralysis; pralidoxime addresses nicotinic toxicity. NPLEX trap: Do not enter a contaminated area or touch wet clothing without appropriate PPE.

Diagnosis: Carbon monoxide poisoning from indoor generator use. Immediate management • Do not enter an unsafe environment. • Move exposed individuals to fresh air when safe. • Activate fire and emergency services. • Administer 100% oxygen. • Monitor cardiac rhythm and neurologic status. • Obtain carboxyhemoglobin by co-oximetry. • Assess ECG, cardiac biomarkers, blood gas and lactate when indicated. • Consider hyperbaric consultation. • Evaluate every potentially exposed household member. CDC warns that ongoing environmental exposure may place other people at risk, so the source must be identified and the environment declared safe before re-entry. Clinical pearl: Carboxyhemoglobin concentration may decline before testing if the patient has already received oxygen, so the exposure history and clinical findings remain essential. NPLEX trap: A normal conventional oxygen-saturation reading does not rule out carbon monoxide poisoning.

Diagnosis: Generalized convulsive status epilepticus. Immediate management • Note the seizure start time. • Protect the head and clear surrounding hazards. • Do not restrain the patient. • Do not insert anything into the mouth. • Position and suction the airway as needed. • Administer oxygen and assist ventilation. • Check glucose. • Activate EMS. • Give an adequate benzodiazepine dose under protocol. • Escalate to second-line antiseizure therapy if convulsions continue. • Prepare for intubation and continuous EEG when refractory status is suspected. The AES algorithm emphasizes rapid, adequately dosed therapy rather than repeated subtherapeutic doses. Potential causes • Medication nonadherence • Stroke or hemorrhage • Infection • Hypoglycemia • Hyponatremia • Toxic ingestion or withdrawal • Head injury • Eclampsia • Brain tumour Clinical pearl: Persistent unconsciousness after visible convulsions stop may represent a postictal state or ongoing nonconvulsive status epilepticus. NPLEX trap: Do not delay benzodiazepine treatment while attempting to obtain IV access; IM or intranasal routes may be used according to protocol.

Diagnosis: Invasive meningococcal disease causing meningitis, meningococcemia and septic shock. Immediate management • Apply droplet precautions. • Activate EMS. • Stabilize airway, breathing and circulation. • Treat shock. • Obtain blood cultures when this does not delay antibiotics. • Administer prompt empiric IV antibiotics. • Perform lumbar puncture when clinically appropriate and safe. • Do not delay antibiotics for imaging or lumbar puncture in a critically ill patient. • Notify public health according to local requirements. • Identify close contacts requiring prophylaxis. CDC guidance emphasizes immediate effective antibiotic therapy and public-health management of exposed contacts. Differential diagnosis • Pneumococcal meningitis • Viral meningitis • Encephalitis • Subarachnoid hemorrhage • Severe sepsis from another source • Rocky Mountain spotted fever or other rickettsial disease • Drug-induced meningitis Clinical pearl: The complete triad of fever, neck stiffness and altered mental status is not present in every meningitis case. NPLEX trap: Do not wait for lumbar-puncture confirmation before treating a critically ill patient with strongly suspected bacterial meningitis.

Diagnosis: Suspected aneurysmal subarachnoid hemorrhage. Immediate management • Activate EMS. • Assess and support ABCs. • Monitor consciousness, pupils and focal neurologic findings. • Control severe hypertension carefully under emergency protocol while avoiding hypotension. • Treat seizures if they occur. • Provide antiemetic and analgesic care without masking deterioration. • Arrange immediate CT and vascular evaluation. • Transfer to a centre with neurocritical-care and aneurysm-treatment capability when confirmed. The AHA/ASA guideline emphasizes rapid diagnosis, specialized care and prompt treatment of the ruptured aneurysm to reduce rebleeding risk. Differential diagnosis • Reversible cerebral vasoconstriction syndrome • Cervical artery dissection • Cerebral venous thrombosis • Meningitis • Intracerebral hemorrhage • Pituitary apoplexy • Acute angle-closure glaucoma • Migraine Clinical pearl: A “sentinel” sudden severe headache may precede a larger aneurysmal rupture and still requires emergency investigation. NPLEX trap: Do not diagnose migraine solely because the neurologic examination becomes normal or the headache improves.

Diagnosis: Severe symptomatic hypotonic hyponatremia causing seizure. Immediate management 1. Protect the airway and prevent injury. 2. Activate EMS. 3. Treat ongoing seizure according to protocol. 4. Administer a controlled 3% hypertonic-saline bolus in an appropriate monitored setting. 5. Reassess neurologic status and sodium frequently. 6. Stop repeated hypertonic therapy after the targeted initial rise or symptom improvement. 7. Identify the underlying cause. 8. Prevent or actively reverse overcorrection when necessary. The cited endocrine emergency guidance uses 150 mL of 3% saline over 20 minutes, repeated as required to achieve an initial 5 mmol/L rise; regional protocols may instead specify a different bolus volume. Possible causes • Thiazide diuretics • SIADH • Excess free-water intake • Adrenal insufficiency • Hypothyroidism • Heart, liver or kidney failure • Vomiting with hypotonic fluid replacement • Medications such as certain antidepressants or antiseizure drugs Key investigations after stabilization • Serum osmolality • Urine osmolality • Urine sodium • Glucose • Renal function • Thyroid assessment • Cortisol assessment when indicated • Medication and volume-status review Clinical pearl: Treatment urgency is determined by neurologic symptoms and the rate of sodium decline, not by the sodium number alone. NPLEX trap: Do not attempt to normalize the sodium rapidly.

Diagnosis: Severe traumatic brain injury with signs of raised intracranial pressure and possible impending herniation. Immediate management 1. Activate EMS and request trauma-centre transfer. 2. Maintain cervical-spine alignment. 3. Open and protect the airway. 4. Provide oxygen and assisted ventilation when necessary. 5. Avoid hypotension. 6. Check glucose. 7. Control external bleeding. 8. Monitor pupils, GCS and vital signs. 9. Avoid unnecessary stimulation or delays for nonessential office testing. Key hospital investigations • Noncontrast head CT • Cervical-spine imaging • CBC and electrolytes • Coagulation studies • Type and screen • Toxicology testing when indicated Pharmacology safety: Sedatives, opioids and paralytics can obscure neurologic findings but may be necessary for airway control under advanced protocols. Botanical safety: Ginkgo, garlic, fish oil and other products with possible antiplatelet effects should be documented, particularly when intracranial bleeding is suspected. Clinical pearl: A patient with a serious TBI can deteriorate rapidly despite initially preserved blood pressure. NPLEX trap: Do not allow a severely obtunded trauma patient to “sleep it off.”

Diagnosis: Suspected high cervical spinal-cord injury with neurogenic shock. Immediate management • Activate EMS. • Maintain manual spinal alignment. • Assess airway and breathing repeatedly. • Administer oxygen and assist ventilation as needed. • Control any bleeding. • Establish IV access when trained and authorized. • Prevent hypothermia. • Avoid unnecessary rolling, sitting or neck movement. • Transfer to a trauma centre. The ACS spinal-injury guidance emphasizes organized assessment of both spinal-column and spinal-cord injury and rapid management of associated respiratory and circulatory compromise. Differential diagnosis • Hemorrhagic shock • Spinal shock • Neurogenic shock • Brain injury • Medication or substance effect • Cardiac injury Clinical pearl: Neurogenic shock is a hemodynamic condition; spinal shock refers to temporary loss of motor, sensory and reflex function below the injury. NPLEX trap: Do not attribute all hypotension after trauma to spinal injury until internal bleeding has been excluded.

Diagnosis: Flail chest with probable pulmonary contusion. Immediate management • Activate EMS. • Provide oxygen. • Monitor continuously. • Assist ventilation if respiratory fatigue or failure develops. • Treat pain without causing excessive respiratory depression. • Assess for pneumothorax, hemothorax and other trauma. • Avoid tightly taping or binding the chest. • Arrange trauma-centre transfer. Updated ACS chest-wall guidance emphasizes multidisciplinary respiratory care, pain control and management of associated rib and sternal injuries. Clinical pearl: The severity of the pulmonary contusion often determines respiratory impairment more than the visible chest-wall movement. NPLEX trap: Do not tightly strap a flail segment in a manner that restricts chest expansion.

Diagnosis: Suspected splenic rupture with hemorrhagic shock. Immediate management 1. Activate EMS. 2. Maintain the airway and oxygenation. 3. Control external bleeding. 4. Establish IV access when authorized. 5. Prevent hypothermia. 6. Keep the patient NPO. 7. Reassess blood pressure, mental status and perfusion. 8. Transfer for urgent operative or interventional management. Key hospital investigations • FAST examination • CBC and coagulation studies • Type and crossmatch • Lactate • CT in a sufficiently stable patient • Immediate surgical evaluation when instability persists Clinical pearl: Significant internal blood loss can occur without any visible external bleeding. NPLEX trap: Do not delay trauma transfer for a full office-based abdominal workup.

Diagnosis: Major thermal burn with suspected inhalation injury and possible carbon-monoxide exposure. Immediate management • Ensure scene safety. • Stop the burning process. • Remove smoldering clothing and constricting items unless adherent. • Activate EMS. • Give high-concentration oxygen. • Assess for early airway control. • Cover burns with clean dry material. • Prevent hypothermia. • Establish IV access when indicated and authorized. • Transfer to a burn centre. Burn-size estimation: The patient’s palm can approximate 1% of total body surface area for small or scattered burns. Avoid • Ice • Butter • Toothpaste • Adhesive dressings • Routine blister rupture • Delayed airway management • Excessive cooling of a patient with a major burn Clinical pearl: A normal or near-normal conventional pulse-oximetry reading does not exclude carbon-monoxide exposure. NPLEX trap: Do not wait for complete airway obstruction before arranging definitive airway management.

Diagnosis: Lightning injury with respiratory or cardiac arrest. Immediate management • Confirm scene safety. • Call EMS. • Touch and assess the lightning victim without fear of residual charge. • Start CPR when required. • Use an AED. • Treat burns and trauma. • Maintain cervical-spine precautions when a fall or blast injury occurred. • Arrange hospital assessment for cardiac, neurologic and musculoskeletal complications. Official Canadian and CDC guidance confirms that lightning victims do not retain a charge and should receive immediate CPR and AED treatment when indicated. Key hospital investigations • ECG and monitoring • Electrolytes • Creatine kinase • Renal function • Urinalysis for myoglobin • Trauma imaging when indicated • Neurologic and hearing assessment Clinical pearl: In a multiple-casualty lightning event, apparently lifeless patients may have reversible respiratory arrest and can deserve early resuscitation priority. NPLEX trap: Do not delay CPR because you believe a lightning victim remains electrically charged.

Diagnosis: Moderate-to-severe accidental hypothermia. Immediate management 1. Activate EMS. 2. Handle the patient gently and keep horizontal. 3. Remove wet clothing. 4. Dry and insulate. 5. Warm the chest, neck, head and groin. 6. Administer warmed oxygen and warmed IV fluids when available under protocol. 7. Monitor cardiac rhythm. 8. Check glucose. 9. Prepare for prolonged resuscitation if cardiac arrest occurs. 10.Transfer to a centre capable of advanced rewarming when unstable. The Wilderness Medical Society emphasizes gentle movement, core warming and transfer decisions based on consciousness, cardiovascular stability, shivering and core temperature. Avoid • Vigorous extremity massage • Unnecessary walking • Alcohol • Direct intense heat to numb skin • Premature termination of resuscitation Clinical pearl: The cessation of shivering in a deteriorating cold patient is an ominous sign, not evidence of improvement. NPLEX trap: Do not force a confused hypothermic patient to exercise.

Diagnosis: Deep frostbite of the foot. Immediate management • Treat hypothermia and major trauma first. • Remove constricting footwear or jewellery. • Protect the frozen area. • Do not allow walking on a thawed frostbitten foot unless unavoidable for survival. • Rewarm in 37–39°C water when refreezing can be prevented. • Provide pain control. • Apply loose, dry protective dressings. • Separate affected digits with clean material. • Arrange urgent transfer. These steps align with the WMS frostbite summary. Do not • Rub the tissue • Apply snow • Use a fire, heating pad or radiator • Break hemorrhagic blisters in the field • Thaw when refreezing is expected Clinical pearl: Rewarming can be intensely painful and requires adequate analgesia. NPLEX trap: Never rub frozen tissue to restore circulation.

Diagnosis: Drowning-associated hypoxic cardiac arrest. Immediate management • Ensure rescuer safety. • Remove the patient from the water. • Activate EMS. • Open the airway. • Give rescue breaths. • Begin compression–ventilation CPR. • Apply an AED. • Administer oxygen when available. • Treat associated hypothermia. • Consider cervical-spine injury when the mechanism suggests diving, boating or major trauma. The WHO defines drowning as respiratory impairment caused by immersion or submersion, with outcomes of death, morbidity or no morbidity. Avoid • Heimlich manoeuvres to drain water • Hanging the patient upside down • Delaying ventilations • Assuming recovery eliminates the need for assessment • Using the term “near-drowning” as the formal diagnosis Clinical pearl: Ventilation is particularly important because drowning arrest usually begins with hypoxia. NPLEX trap: Do not waste time attempting to expel water from the lungs before beginning ventilation and CPR.

Diagnosis: Snakebite envenomation with progressive local injury, coagulopathy and shock. Immediate management 1. Ensure scene safety. 2. Move away from the snake. 3. Activate EMS. 4. Keep the patient calm and still. 5. Immobilize the affected limb. 6. Remove rings, bracelets and tight clothing. 7. Mark the leading edge of swelling and record the time. 8. Monitor ABCs. 9. Avoid food and drink if consciousness is impaired or procedures may be needed. 10.Transfer for antivenom and supportive care. Do not • Cut the bite • Suck the venom • Apply ice • Use electric shock • Apply herbal preparations • Attempt to capture the snake by hand • Apply a tight arterial tourniquet WHO specifically advises against traditional first-aid methods and herbal medicines that delay hospital care. Hospital management • Species-appropriate antivenom • Coagulation testing • CBC, renal function and urinalysis • Analgesia • Respiratory support for neurotoxicity • Treatment of shock • Monitoring for antivenom reactions • Surgical assessment only when clinically indicated Clinical pearl: A photograph taken from a safe distance may help identification, but no one should risk another bite to catch the snake. NPLEX trap: Do not cut, suck or tightly tourniquet a snakebite.

Diagnosis: Severe foreign-body airway obstruction in an infant. Immediate management 1. Activate emergency assistance. 2. Give five back blows. 3. Give five chest thrusts. 4. Repeat until the object is expelled or the infant becomes unresponsive. 5. Begin CPR if unresponsive. 6. Look for and remove only a visible object. 7. Arrange medical assessment after a significant choking event. Clinical pearl: An infant’s liver and abdominal organs are relatively vulnerable; abdominal thrusts are therefore not the recommended choking treatment. NPLEX trap: Use chest thrusts—not abdominal thrusts—for a choking infant.

Working diagnosis: Prolonged febrile seizure. Differential diagnosis • Meningitis or encephalitis • Hypoglycemia • Hyponatremia • Toxic ingestion • Epilepsy • Head injury • Shivering or rigors misidentified as a seizure Immediate management • Record seizure duration. • Protect the head and clear nearby hazards. • Maintain airway positioning. • Give oxygen and ventilation support when needed. • Check glucose. • Administer a benzodiazepine for a seizure lasting at least five minutes. • Activate EMS. • Assess for meningitis, sepsis and other causes. Febrile seizures typically occur in children between approximately 6 months and 5 years of age, but fever should not automatically be assumed to be the sole cause of prolonged or focal convulsions. Clinical pearl: The first priority is seizure and airway management—not rapid cooling of the child. NPLEX trap: Never place an object in a convulsing child’s mouth.

Diagnosis: Severe gastroenteritis-associated dehydration with hypovolemic shock. Immediate management 1. Activate EMS. 2. Maintain airway and oxygenation. 3. Check glucose. 4. Obtain IV or IO access. 5. Administer isotonic crystalloid in measured aliquots. 6. Reassess after every aliquot. 7. Correct electrolyte and glucose abnormalities. 8. Replace ongoing gastrointestinal losses. 9. Restart oral rehydration when consciousness and circulation permit. WHO Plan C identifies severe dehydration as requiring rapid fluid replacement, usually with IV therapy and admission or urgent referral. Differential diagnosis • Septic shock • Diabetic ketoacidosis • Adrenal crisis • Intestinal obstruction • Intussusception • Hemolytic-uremic syndrome • Toxic ingestion Clinical pearl: Children can maintain blood pressure until late shock; hypotension is therefore an ominous finding. NPLEX trap: Do not give oral fluids to a lethargic child who cannot protect the airway.

Diagnosis: Ruptured tubal ectopic pregnancy with hemorrhagic shock. Immediate management • Activate EMS. • Assess airway and breathing. • Provide oxygen when indicated. • Establish large-bore IV access when authorized. • Keep the patient NPO. • Prevent hypothermia. • Monitor mental status and circulation. • Arrange urgent obstetric and surgical management. • Notify the receiving facility of suspected internal hemorrhage. Key hospital investigations • Quantitative beta-hCG • Transvaginal ultrasonography • CBC • Type and crossmatch • Coagulation studies • Renal and liver function as indicated Clinical pearl: The quantity of visible vaginal bleeding does not reflect the amount of intraperitoneal blood loss. NPLEX trap: Methotrexate is not appropriate for an unstable patient with suspected rupture.

Diagnosis: Postpartum hemorrhage from uterine atony with hemorrhagic shock. Immediate management 1. Call for emergency obstetric and resuscitation support. 2. Massage the uterus. 3. Administer uterotonic therapy under protocol. 4. Assess for retained placenta and genital-tract trauma. 5. Establish large-bore IV access. 6. Begin balanced hemorrhage resuscitation. 7. Obtain blood products rapidly. 8. Prevent hypothermia. 9. Empty the bladder when appropriate. 10.Escalate to balloon tamponade, embolization or surgery when bleeding persists. ACOG identifies postpartum hemorrhage as a potentially life-threatening pregnancy-related emergency that may present in obstetric or nonobstetric settings. Medication safety • Methylergonovine can worsen severe hypertension. • Carboprost can provoke bronchospasm and is generally avoided in significant asthma. • Medication selection must follow the patient’s contraindications and emergency protocol. Clinical pearl: Do not wait for hypotension; pregnancy-related physiologic compensation can initially conceal major blood loss. NPLEX trap: A quantified loss below 1,000 mL can still constitute a dangerous hemorrhage when signs of hypovolemia are present.

Diagnosis: Eclampsia with severe hypertension. Immediate management • Call EMS and obstetric support. • Protect the patient from injury. • Maintain airway and oxygenation. • Position with left uterine displacement when feasible. • Administer magnesium sulfate. • Treat persistent severe hypertension under protocol. • Monitor fetal and maternal status. • Check glucose. • Prepare for delivery after stabilization. ACOG considers severe hypertension and eclampsia high-acuity maternal emergencies requiring appropriate medication access and escalation capability. Magnesium-toxicity monitoring • Respiratory rate • Deep-tendon reflexes • Urine output • Mental status Calcium is used as an antidote for clinically important magnesium toxicity under an emergency protocol. Clinical pearl: Eclampsia can occur before, during or after delivery. NPLEX trap: Do not select diazepam as the preferred routine seizure-prevention medication when magnesium sulfate is available and eclampsia is suspected.

Diagnosis: Acute suicidal crisis with plan, intent and immediate access to lethal means. Immediate management 1. Remain calm and nonjudgmental. 2. Do not leave the patient alone. 3. Remove access to the identified means when this can be done safely. 4. Assess plan, intent, timeframe, previous attempts and substance use. 5. Identify protective factors and available support. 6. Activate emergency psychiatric services. 7. Arrange safe transport. 8. Document the assessment, rationale and disposition. 9. Do not permit the patient to drive alone. SAMHSA’s SAFE-T model uses five steps: identify risk factors, identify protective factors, conduct the suicide inquiry, determine risk and intervention, and document the plan. Clinical pearl: Asking directly about suicide does not create suicidal intent; it allows risk to be identified and addressed. NPLEX trap: Never rely solely on a promise that the patient will not self-harm.

Diagnosis: Occupational percutaneous blood exposure. Immediate management • Wash needlestick and cut injuries with soap and water. • Irrigate mucous membranes with water. • Report the exposure immediately. • Document the device, depth and visible blood. • Test the source patient according to law and policy. • Obtain baseline exposed-worker testing. • Begin HIV PEP promptly when indicated. • Review hepatitis B immunity and provide prophylaxis when needed. • Arrange HCV follow-up testing. • Provide counselling and follow-up care. CDC notes that occupational HIV transmission is rare, but rapid assessment and appropriate PEP remain necessary after a significant exposure. Do not • Use bleach or caustic chemicals • Delay reporting • wait for symptoms • Share the incident unnecessarily outside confidentiality requirements • Assume gloves eliminate all risk Clinical pearl: A deep injury from a blood-filled hollow-bore needle generally carries greater risk than a superficial injury from a solid needle. NPLEX trap: HIV PEP is most useful when started promptly, not after seroconversion testing becomes positive.

Diagnosis: Mass-casualty incident overwhelming routine clinic capacity. Core response priorities 1. Ensure scene and facility safety. 2. Activate the emergency or disaster plan. 3. Establish clear incident command. 4. Request EMS, fire, police and hospital support. 5. Create triage, immediate-treatment and minor-treatment areas. 6. Control catastrophic hemorrhage. 7. Perform only rapid lifesaving interventions during initial triage. 8. Label, document and track patients. 9. Reassess triage categories. 10.Preserve communication and supply chains. WHO emphasizes preparedness, coordinated leadership, emergency-unit surge management and structured triage for mass-casualty events. Clinical pearl: Mass-casualty triage does not abandon individual ethics; it adapts care to extreme resource imbalance with the goal of maximizing survival. NPLEX trap: Do not provide prolonged treatment to the first patient encountered while numerous unassessed casualties remain.

Diagnosis: Shoulder dystocia. Emergency sequence 1. Announce the emergency. 2. Call for obstetric, anesthesia and neonatal help. 3. Note the time of head delivery. 4. Ask the patient to stop pushing briefly. 5. Avoid fundal pressure. 6. Use McRoberts positioning. 7. Apply suprapubic pressure. 8. Escalate to internal rotational or posterior-arm manoeuvres when trained. 9. Consider an all-fours position when appropriate. 10.Prepare for neonatal resuscitation and maternal hemorrhage. RCOG guidance describes McRoberts positioning, suprapubic pressure, internal manoeuvres and all-fours repositioning as established approaches to releasing the impacted shoulder. Potential fetal complications • Brachial-plexus injury • Humeral or clavicular fracture • Hypoxic injury Potential maternal complications • Postpartum hemorrhage • Severe perineal trauma • Uterine or pelvic injury Shoulder dystocia is difficult to predict and may occur even when fetal weight is not markedly elevated. Clinical pearl: The goal is to change the relationship between the fetal shoulders and the maternal pelvis—not to pull harder. NPLEX trap: Never apply fundal pressure during shoulder dystocia.