EM Weeks 9-10

How may posterior circulation strokes present when not following the classic FAST symptoms?

Sudden balance problems, diplopia, visual symptoms, severe gait instability, or vertigo.

When evaluating an acute ischemic stroke, what time point must be established rather than symptom discovery time?

Last known well.

What does the NIHSS measure and what are its key diagnostic limitations?

Measures severity; does not diagnose stroke and may underestimate posterior or disabling deficits.

Does a low NIHSS score automatically indicate that a stroke is minor or nondisabling?

No.

What immediate point-of-care lab test should be checked in a suspected stroke evaluation?

Blood glucose.

What is the primary question answered by a noncontrast head CT in acute stroke?

Is there blood or a large established infarct?

What diagnostic question does CTA head/neck answer during an acute stroke workup?

Is there an LVO, aneurysm, or vascular lesion?

What do CT perfusion or MRI answer in selected late- or unknown-onset stroke patients?

Is there potentially salvageable tissue?

How do IV thrombolysis and endovascular thrombectomy fit together for treatable LVO patients?

They are complementary when qualifying for both; thrombectomy candidacy extends beyond thrombolysis windows.

What is the required blood pressure threshold prior to initiating IV thrombolysis?

What is the target blood pressure threshold during the first 24 hours after IV thrombolysis?

What blood pressure management strategy is often appropriate in acute ischemic stroke without reperfusion therapy?

Permissive hypertension.

How is TIA differentiated from ischemic stroke based on the tissue-based definition?

TIA has transient symptoms without infarction; MRI-proven acute infarct classifies as ischemic stroke.

What is the clinical role and limitation of the ABCD² risk score?

It is a risk tool, not a stand-alone disposition decision.

What clinical factors push a TIA evaluation toward observation or admission rather than discharge?

Recurrent symptoms, high-risk findings, incomplete evaluation, or unreliable follow-up.

What is the anatomical pattern of intracranial hemorrhage (ICH)?

Blood within the brain parenchyma.

What is subarachnoid hemorrhage (SAH) and what is its classic presenting symptom?

Blood in subarachnoid spaces/cisterns, often presenting with thunderclap headache.

What is the characteristic CT appearance and common etiology of a subdural hematoma?

Crescent-shaped extra-axial blood, often following trauma.

What interventions comprise the core management bundle for intracranial hemorrhage (ICH)?

Control BP, reverse anticoagulation, reassess neuro status, involve neurosurgery early, repeat CT if deteriorating.

What defines a thunderclap headache?

Abrupt onset with rapid maximal intensity.

What is the first-line imaging modality for evaluating a suspected thunderclap headache?

Noncontrast head CT.

What distinct diagnostic questions do lumbar puncture (LP) and CTA answer in suspected SAH?

LP looks for evidence of hemorrhage; CTA evaluates for an aneurysm or vascular source.

Besides SAH, what other vascular emergencies belong in the differential for thunderclap headache?

Cerebral venous thrombosis (CVT), RCVS, and cervical artery dissection.

When should cerebral venous thrombosis (CVT) be strongly suspected?

Headache with seizure, focal deficits, papilledema, or a prothrombotic setting like pregnancy/postpartum.

What advanced imaging modalities evaluate the venous system when noncontrast CT is normal in suspected CVT?

CTV or MRV.

Does the presence of hemorrhagic venous infarction in CVT automatically preclude anticoagulation therapy?

No.

What clinical features favor vasovagal syncope over a true seizure?

Vasovagal-type prodrome and rapid return to baseline.

What clinical features favor a seizure diagnosis over syncope?

Prolonged confusion, lateral tongue injury, or a convincing postictal period.

At what duration should ongoing convulsive seizure activity be actively treated as status epilepticus?

At 5 minutes.

What is the first-line medication class for status epilepticus and how should it be administered?

Adequate benzodiazepine dose promptly via any effective route, without waiting for IV access.

What defines refractory status epilepticus and what management escalation is required?

Persistent seizure despite benzodiazepine plus second-line therapy; requires airway control, anesthetics, and EEG.

Which specific patient findings mandate a head CT prior to lumbar puncture in suspected bacterial meningitis?

Focal deficits, new seizure, papilledema, significant immunocompromise, or markedly impaired consciousness.

If a head CT is required prior to LP in suspected bacterial meningitis, what must not be delayed?

Empiric antibiotics and dexamethasone.

What clinical presentation and imaging abnormalities point toward HSV encephalitis?

Fever, personality change, confusion, aphasia/focal findings, seizure, and temporal-lobe abnormalities.

What is the initial treatment strategy for suspected HSV encephalitis?

Start IV acyclovir immediately on high suspicion without waiting for PCR confirmation.

What are the common CT-risk features in minor head injury?

Age, vomiting, skull-fracture findings, altered GCS, dangerous mechanism and anticoagulation.

What are the major preventable secondary insults in significant traumatic brain injury (TBI)?

Hypoxemia, hypotension, abnormal ventilation, and delayed recognition of neurologic deterioration.

What physical exam findings on HINTS testing raise concern for central vertigo?

Normal head impulse, direction-changing/vertical nystagmus, or skew deviation.

Does a normal noncontrast head CT rule out a posterior circulation stroke causing vertigo?

No.

What classic clinical presentation defines cauda equina syndrome?

Urinary retention, saddle anesthesia, and bilateral symptoms or progressive weakness.

What are the required urgent diagnostic and management steps for cauda equina syndrome?

Urgent MRI and spine consultation.

What are the hallmark clinical features and key monitoring parameters in Guillain-Barré syndrome?

Progressive symmetric weakness with decreased reflexes; monitor respiratory mechanics, bulbar function, dysautonomia.

What are the primary treatments for Guillain-Barré syndrome, and what class of drug is ineffective?

IVIG or plasma exchange are treatments; steroids are not.

What physical exam findings indicate brain herniation requiring urgent emergency intervention?

Falling level of consciousness, new fixed pupil, and posturing.

What immediate physiologic priorities should be evaluated first in a poisoned patient?

Airway/ventilation, glucose, vitals/temp, ECG (QRS/QTc), and physical exam (pupils, skin, bowel sounds, tone).

What clinical features characterize the anticholinergic toxidrome?

Hot, dry, mydriatic, agitation/confusion, decreased bowel activity, and urinary retention.

What clinical features characterize the sympathomimetic toxidrome?

Hot, agitated, mydriasis, tachycardia/hypertension, and diaphoresis.

What clinical features characterize the cholinergic toxidrome?

Miosis, secretions, bronchorrhea/bronchospasm, and GI/GU hyperactivity.

What are the key clinical diagnostic clues for serotonin syndrome?

Rapid onset with clonus and hyperreflexia.

What ECG findings suggest sodium-channel blocker toxicity and what is the key medical treatment?

Widened QRS and terminal R in aVR; treated with sodium bicarbonate.

When can you use the Rumack-Matthew nomogram?

Accurate time of a single acute ingestion of acetaminophen and a level draw 4 hours or later. Will tell you whether to start acetylcysteine and the risk of hepatotoxicity from this ingestion. N-acetylcysteine works best when given early.

What constellation of symptoms suggests salicylate toxicity?

Tinnitus, tachypnea/hyperpnea, and altered mental status.

What acid-base abnormality is expected in salicylate toxicity?

A mixed acid-base disturbance.

Why must clinicians exercise caution when intubating a patient with severe salicylate toxicity?

Intubation may disrupt the patient's protective compensatory hyperventilation.

Which substance withdrawal syndromes can become directly life-threatening?

Alcohol and benzodiazepine withdrawal.

What is the mainstay pharmacotherapy for alcohol and benzodiazepine withdrawal?

Benzodiazepines.

How does opioid withdrawal differ from alcohol withdrawal in clinical severity and management?

Opioid withdrawal is uncomfortable rather than fatal; treated symptomatically or with ED-initiated buprenorphine.

What clinical features distinguish delirium from primary psychiatric illness?

Acute onset, fluctuation, inattention, disorientation, and often abnormal vital signs.

New psych symptoms in an older patient or patient with abnormal vitals should make you consider medical, toxicologic, infectious, neurologic or metabolic cause.

What is the preferred initial approach for managing agitation in the ED when safe?

Verbal de-escalation.

What essential components must be included in a true psychiatric safety plan?

Coping strategies, supports, crisis resources, lethal-means restriction, and specific follow-up.

What are the key features of heat exhaustion?

Weak, dizzy, nausea, mental status remains intact.

What key clinical feature distinguishes heat stroke from heat exhaustion?

CNS dysfunction (confusion, delirium, seizure, or coma) present in heat stroke.

What is the preferred cooling method for heat stroke and when should it be initiated?

Ice-water immersion preferred; initiate immediately without waiting for labs, IV access, or imaging. Antipyretics do not treat heat stroke!

What exposures and presentations should raise clinical suspicion for carbon monoxide (CO) poisoning?

Generator, heater, fire, or enclosed space exposure, especially with multiple sick individuals.

What is a key diagnostic limitation of standard pulse oximetry in suspected carbon monoxide poisoning?

Standard pulse oximetry can appear normal.

What is the immediate initial treatment for suspected carbon monoxide poisoning?

High-concentration oxygen.

What are signs that should prompt consideration of hyperbaric consultation?

Significant neurologic or cardiac toxicity.

What are the stages of hypothermia?

Mild: 32-35 C - shivering, alert

Moderate: 28-32 C - shivering stops, increasing CNS depression

Severe:

How do you determine the type of rewarming needed for hypothermia?

Severity determines the type. Mild needs passive external warming, moderate needs active external rewarming (warm IV fluids if needed) and severe needs active internal rewarming (ECLS or ECMO)

What is the fundamental management rule regarding tissue thawing in frostbite?

Do not thaw tissue if it may refreeze. Rewarm rapidly when refreezing is no longer possible. Avoid rubbing or massaging tissue. Severe frostbite deserves early specialty involvement.

What is the definitive medical intervention for serious altitude illnesses (HACE and HAPE)?

Descent.

ACS = stop ascent

HACE = ataxa/AMS; urgent descent

HAPE = dyspnea at rest/hypoxemia; oxygen and descent

What is the primary underlying mechanism of injury in drowning, and what resuscitation aspect is critical?

Drowning is primarily a hypoxic injury; ventilation is critical.

What is the primary mechanism of diving decompression illness?

Decompression illness and arterial gas embolism require high concentration oxygen and early dive/hyperbaric consultation.

Pneumothorax must be treated before recompression.

What pre-hospital interventions are contraindicated in the management of snakebites?

Do not use cutting, suction, ice, or tourniquets.

What are the time-sensitive medical management priorities for neutropenic fever?

Obtain cultures and promptly administer broad antipseudomonal antibiotics.

What electrolyte and lab abnormalities define tumor lysis syndrome?

Hyperkalemia, hyperphosphatemia, hyperuricemia, and hypocalcemia.

AKI, dysrhythmias and seizures can result.

What clinical constellation requires urgent MRI and specialty involvement for suspected malignant spinal cord compression?

History of cancer plus new back pain and neurologic symptoms.

What is the universal first action when a patient develops a transfusion reaction?

Stop the transfusion immediately and assess the patient.

Why requires careful evaluation in nonfatal strangulation even with minimal external findings?

Nonfatal strangulation may cause serious internal injury despite minimal external physical findings.