The Daily Differential — Friday, May 1, 2026

2 of 5

Anxiety / Panic Disorder

Panic attacks are common ED presentations, but “anxiety” is a diagnosis of exclusion when symptoms overlap with ACS, PE, arrhythmia, hypoglycemia,...

At the Bedside

Panic attack features:
Abrupt surge of intense fear/discomfort peaking within minutes.
Palpitations, chest tightness, dyspnea, tremor, diaphoresis, paresthesias, dizziness, derealization, fear of dying/losing control.
Do not anchor early. Screen for mimics:
ACS, dysrhythmia, PE, asthma, pneumothorax.
Hypoglycemia, hyperthyroidism, pheochromocytoma.
Stimulants, cannabis, hallucinogens, caffeine toxicity.
Alcohol/benzodiazepine withdrawal.
Sepsis, anemia, pregnancy-related disease.
Focused history:
Onset, triggers, duration, prior episodes.
Chest pain, exertional symptoms, syncope, unilateral leg swelling, hemoptysis, fever.
Medications/substances, caffeine/energy drinks, withdrawal risk.
Psychiatric history, suicidality, homicidality, psychosis, domestic violence.
Exam/workup guided by risk:
Vitals, cardiopulmonary exam, neuro exam, mental status.
POC glucose for concerning symptoms.
ECG for palpitations/chest pain, older patients, cardiac risk, stimulant use.
Pregnancy test when relevant.
Troponin, D-dimer/CTPA, TSH, CBC/CMP only when clinically indicated.
ED management:
Calm environment, verbal reassurance, normalize physiologic symptoms.
Coach slow breathing/grounding; avoid paper-bag breathing because hypoxia/PE/asthma can be missed.
If severe distress and dangerous causes reasonably excluded, use short-acting anxiolytic cautiously.
Avoid initiating chronic benzodiazepines from the ED when possible.
Consider hydroxyzine for non-benzodiazepine symptomatic relief.
Provide crisis resources, outpatient mental health follow-up, and return precautions.
Disposition:
Discharge if symptoms resolve, medical mimics reasonably excluded, no SI/HI/psychosis, reliable follow-up.
Psychiatric evaluation/admission for suicidality, grave disability, psychosis, unsafe home situation, or inability to care for self.

A Classic Presentation

A 27-year-old woman presents with sudden palpitations, chest tightness, tingling around her mouth, and fear she is dying. Symptoms peaked within 10 minutes after a stressful event. Vitals show mild tachycardia, ECG is sinus tachycardia, glucose is normal, pregnancy test is negative, and she has no PE/ACS risk factors or suicidal ideation. After reassurance, coached breathing, and 0.5 mg lorazepam PO, symptoms resolve and she is discharged with outpatient behavioral health follow-up.

Study Directive

Create a personal “panic mimic” checklist: ACS, PE, arrhythmia, hypoglycemia, thyroid, stimulant intoxication, withdrawal.
Practice a 60-second reassurance script that validates symptoms without prematurely labeling them psychiatric.
Review when to obtain ECG, troponin, D-dimer, pregnancy test, and TSH in anxiety-like presentations.
Learn local outpatient mental health and crisis referral resources.

Key Medications

Lorazepam: 0.5–1 mg PO/SL/IV; may repeat carefully. Higher doses increase respiratory depression/falls, especially with opioids/alcohol.
Diazepam: 2–5 mg PO/IV for acute anxiety; avoid or reduce in older adults and hepatic disease.
Hydroxyzine: 25–50 mg PO/IM every 6 hr PRN; sedating, anticholinergic effects, caution QT prolongation.
Propranolol: 10–20 mg PO for performance-type autonomic symptoms; avoid in asthma, bradycardia, hypotension, decompensated HF.
SSRIs/SNRIs: first-line chronic therapy but usually not an ED acute fix; start only if follow-up and counseling are clear.
Pediatric note: avoid casual benzodiazepine use; evaluate for toxicologic, endocrine, abuse, and psychiatric causes. Dosing is weight-based.

High-Yield Pearls

Panic is common; first-time “panic” in an older patient is a medical diagnosis until proven otherwise.
Hyperventilation causes respiratory alkalosis, which lowers ionized calcium and can produce perioral numbness and carpopedal spasm.
Benzodiazepines work quickly but can worsen dependence, falls, delirium, and respiratory depression.

Board Question

A 24-year-old patient presents with recurrent episodes of sudden fear, palpitations, dyspnea, and paresthesias that peak within minutes. Between episodes she worries about having another attack. Vitals and ECG are normal. Which diagnosis best fits?

APanic disorder
BGeneralized anxiety disorder
CSomatic symptom disorder
DAcute psychosis

Reveal answer

Correct: A

Panic disorder. Panic disorder involves recurrent unexpected panic attacks plus persistent concern or maladaptive behavior related to future attacks. GAD is more chronic excessive worry rather than discrete abrupt episodes.

Recent Literature

Review or guideline Diagnosis and management of generalized anxiety disorder and panic disorder in adults
Am Fam Physician, 2015 · cited 230×
Recent clinical Measuring approach-avoidance behavior in patients with panic disorder using the human elevated plus maze in mixed reality
J Psychiatr Res, 2026

3 of 5

Approach to Altered Mental Status

Altered mental status is a symptom, not a diagnosis, and time-critical reversible causes include hypoglycemia, hypoxia, opioid toxicity, sepsis, stroke,...

At the Bedside

First 60 seconds:
Assess airway, breathing, circulation, disability.
Vitals including temperature and oxygen saturation.
POC glucose immediately.
Consider naloxone if respiratory depression/miosis/opioid exposure.
Treat seizures, hypoxia, hypotension, hyperthermia, and severe agitation.
Rapid differential: AEIOU-TIPS style
Alcohol/acidosis, epilepsy/electrolytes/endocrine, insulin, overdose/oxygen, uremia.
Trauma/temperature, infection, psychiatric/poisoning, stroke/shock.
Key history sources:
EMS, family, pill bottles, medication list, anticoagulants, diabetes meds, substance use, baseline cognition, last known well, trauma/falls.
Exam:
GCS/mental status pattern, pupils, toxidromes, meningismus, skin findings, track marks, trauma, focal neuro deficits.
Check for asterixis, clonus/rigidity, nystagmus, odor, urinary retention.
POC/bedside testing:
Glucose, ECG, temperature, end-tidal CO₂ if sedated/overdose.
Bedside ultrasound for shock/volume status when indicated.
Labs commonly considered:
CBC, CMP, Mg, VBG/ABG, lactate, UA, pregnancy test, ethanol level, acetaminophen/salicylate levels if overdose possible.
TSH, ammonia, cortisol, cultures, toxicology testing selectively.
Troponin/BNP if cardiac concern.
Imaging/procedures:
CT head for trauma, anticoagulation, focal deficit, severe headache, seizure with persistent AMS, immunocompromise, suspected bleed/mass, or unclear unexplained coma.
CTA/CTP for stroke syndromes.
LP for meningitis/encephalitis/SAH after imaging if indicated.
EEG if nonconvulsive status epilepticus suspected.
Empiric ED treatments:
Dextrose for hypoglycemia.
Thiamine in malnourished/alcohol-use patients, ideally before glucose but never delay dextrose.
Naloxone for opioid-induced respiratory depression.
Broad-spectrum antibiotics ± antivirals for suspected CNS infection/sepsis.
Benzodiazepines for seizures, alcohol/benzo withdrawal, sympathomimetic toxicity.
Cooling for hyperthermia; warming for hypothermia.
Disposition:
ICU for airway risk, persistent coma, shock, sepsis, severe metabolic derangement, status epilepticus, severe toxidrome, intracranial catastrophe.
Admit for persistent unexplained AMS, unsafe discharge, delirium, or new neurologic deficits.
Discharge only if reversible benign cause is identified, baseline returns, and safety/follow-up are reliable.

A Classic Presentation

EMS brings a 62-year-old man found confused on the floor. He is febrile, tachycardic, and oriented only to name. Glucose is 42 mg/dL, and after IV dextrose he improves but remains confused with neck stiffness. CT head shows no mass effect, antibiotics and acyclovir are started, blood cultures are obtained, and LP is performed for suspected meningoencephalitis. He is admitted to the ICU.

Study Directive

Memorize a first-minute AMS algorithm: ABCs, vitals/temp, glucose, naloxone if hypoventilating, seizure control.
Build a toxidrome card with pupils, skin, bowel sounds, temperature, and mental status.
Practice listing CT head indications for AMS without looking.
Review local meningitis/encephalitis antibiotic order set and dosing.

Key Medications

Dextrose: D50W 25 g IV; alternative D10W 100–250 mL IV titrated. Pediatrics often D10 5 mL/kg; neonates D10 2 mL/kg.
Thiamine: 100 mg IV/IM commonly; for suspected Wernicke encephalopathy, 500 mg IV TID is often used — check institutional protocol.
Naloxone: 0.04 mg IV initial if opioid-dependent, titrate every 2–3 min to ventilation; typical 0.4–2 mg IV/IN/IM; severe apnea may require 2–4 mg. Infusion often 2/3 effective reversal dose per hour.
Lorazepam for seizure: 0.1 mg/kg IV, usual adult 2–4 mg, repeat once.
Midazolam for seizure: 10 mg IM for adult >40 kg; 5 mg IM for 13–40 kg.
Haloperidol for severe agitation: 2.5–5 mg IM/IV; monitor QT/extrapyramidal effects.
Droperidol: 2.5–5 mg IM/IV for agitation/nausea; monitor QT risk per policy.
Olanzapine: 5–10 mg PO/ODT/IM; avoid IM olanzapine close in time to parenteral benzodiazepines due to respiratory depression risk.
Ketamine for severe excited delirium/agitation: 4–5 mg/kg IM or 1–2 mg/kg IV; monitor airway and emergence. Dosing varies by protocol.
Ceftriaxone for meningitis coverage: 2 g IV q12h.
Vancomycin: 15–20 mg/kg IV; check dosing reference/institutional protocol.
Acyclovir for HSV encephalitis: 10 mg/kg IV q8h using ideal/adjusted body weight per protocol; renal adjust.

High-Yield Pearls

In AMS, glucose is a vital sign.
“Psychiatric” AMS should have normal vitals, normal attention, and no fluctuating consciousness; delirium is medical until proven otherwise.
Nonconvulsive status epilepticus can present as persistent confusion after a seizure or unexplained coma — consider EEG.

Board Question

An obtunded patient has pinpoint pupils and respirations of 6/min. Oxygen saturation is 84%. What is the most appropriate initial antidotal therapy?

AFlumazenil 0.2 mg IV
BNaloxone titrated to adequate ventilation
CPhysostigmine 2 mg IV
DHaloperidol 5 mg IM

Reveal answer

Correct: B

Naloxone titrated to adequate ventilation. Respiratory depression with miosis strongly suggests opioid toxicity. Naloxone should be titrated to restore ventilation, not necessarily full arousal, to avoid acute withdrawal.

Recent Literature

Review or guideline A definition and classification of status epilepticus--Report of the ILAE Task Force on Classification of Status Epilepticus
Epilepsia, 2015 · cited 2320×
Recent clinical Emergency Medicine Residents in the Prehospital Setting: Does this Augment Training?
Prehosp Emerg Care, 2026

4 of 5

Approach to Headache

Most ED headaches are benign primary headache syndromes, but the danger is missing SAH, meningitis, cerebral venous sinus thrombosis, dissection,...

At the Bedside

First classify: primary vs secondary headache.
Primary: migraine, tension, cluster.
Secondary: vascular, infectious, traumatic, pressure-related, toxic/metabolic, ocular, medication-related.
Red flags — SNOOP-style:
Systemic symptoms: fever, cancer, immunosuppression, pregnancy/postpartum.
Neurologic deficit, AMS, seizure, papilledema.
Onset thunderclap/maximal at onset.
Older age >50 with new headache.
Pattern change, positional, precipitated by exertion/sex/Valsalva, post-trauma.
Focused history:
Time to maximal intensity, first/worst, prior similar headaches.
Fever/neck stiffness, trauma, anticoagulants.
Vision loss/eye pain, jaw claudication, pregnancy/postpartum.
CO exposure, toxins, medication overuse.
Exam:
Full neuro exam, mental status, gait if possible.
Fundoscopy if concern for papilledema.
Neck stiffness, rash, temporal artery tenderness.
Eye exam: visual acuity, pupils, IOP if glaucoma concern.
Sinus/ear/dental/TMJ as appropriate.
Workup by suspected diagnosis:
Thunderclap: noncontrast CT head; LP/CTA if needed.
Meningitis/encephalitis: blood cultures, antibiotics early, LP; CT before LP if focal deficits, papilledema, immunocompromise, new seizure, significant AMS.
Giant cell arteritis: ESR/CRP, platelets; start steroids if suspected; arrange biopsy/ultrasound.
CVST: consider in pregnancy/postpartum, OCP, thrombophilia, cancer; CT venogram/MR venogram.
Dissection: unilateral head/neck pain, Horner syndrome, neuro symptoms; CTA head/neck.
Acute angle-closure glaucoma: eye pain, halos, mid-dilated pupil, high IOP; emergent ophthalmology.
Treatment of common primary headaches:
Migraine: dopamine antagonist + NSAID ± acetaminophen/fluids; add dexamethasone to reduce recurrence in selected patients.
Avoid opioids; associated with recurrence, dependence, and worse long-term outcomes.
Cluster: high-flow oxygen + triptan if no contraindication.
Disposition:
Discharge if benign primary headache, improved, normal neuro exam, no red flags requiring inpatient workup.
Admit/consult for secondary headache, abnormal neuro findings, CNS infection, SAH, CVST, dissection, glaucoma, GCA with visual symptoms, intractable pain/vomiting.

A Classic Presentation

A 34-year-old woman with prior migraines presents with unilateral throbbing headache, photophobia, nausea, and no neurologic deficits. The headache built gradually over 2 hours and resembles prior episodes. She has normal vitals, no meningismus, and no red flags. She receives IV fluids, prochlorperazine, diphenhydramine, ketorolac, and dexamethasone with significant improvement and is discharged with return precautions.

Study Directive

Memorize SNOOP red flags and practice applying them to 10 headache cases.
Draw your SAH diagnostic algorithm including CT timing and LP/CTA decision points.
Review diagnostic clues for GCA, CVST, dissection, meningitis, glaucoma, and CO poisoning.
Build a default ED migraine order set and know contraindications to NSAIDs/triptans.

Key Medications

Metoclopramide: 10 mg IV/IM; often give with diphenhydramine if akathisia risk.
Prochlorperazine: 10 mg IV/IM.
Diphenhydramine: 12.5–25 mg IV/PO for akathisia prevention/treatment; may cause sedation.
Ketorolac: 15 mg IV or 30 mg IM; avoid in renal failure, GI bleed, anticoagulation, late pregnancy.
Acetaminophen: 1000 mg PO/IV.
Dexamethasone: 10 mg IV/PO once to reduce migraine recurrence.
Magnesium sulfate: 1–2 g IV over 15–30 min; useful in migraine with aura/pregnancy contexts.
Valproate: 500–1000 mg IV; avoid in pregnancy/liver disease. Use varies — check reference if uncertain.
Sumatriptan: 6 mg subQ once; may repeat after 1 hr, max 12 mg/day. Avoid in CAD, stroke/TIA, uncontrolled HTN, hemiplegic/basilar migraine.
Cluster headache oxygen: 100% O₂ via nonrebreather 12–15 L/min for 15–20 min.
GCA steroids: prednisone 40–60 mg PO daily if no visual symptoms; methylprednisolone 500–1000 mg IV daily for visual loss/high-risk features — consult ophthalmology/rheumatology; protocols vary.
Pediatric note: migraine regimens are weight-based; dopamine antagonists and NSAIDs are commonly used with age-specific dosing.

High-Yield Pearls

Thunderclap headache is SAH until proven otherwise, but also consider RCVS, dissection, CVST, pituitary apoplexy, and exertional causes.
New headache after age 50 is secondary until proven otherwise.
Migraine treatment works best when antiemetic dopamine antagonists, NSAIDs, and fluids are used early; opioids are poor migraine care.

Board Question

A 68-year-old woman presents with new unilateral temporal headache, scalp tenderness, and jaw pain while chewing. She has transient blurry vision. What is the next best step?

ADischarge with NSAIDs and neurology follow-up
BStart corticosteroids immediately and obtain ESR/CRP
CPerform LP before any treatment
DTreat with sumatriptan

Reveal answer

Correct: B

Start corticosteroids immediately and obtain ESR/CRP. This is concerning for giant cell arteritis, which can cause irreversible vision loss. Steroids should not be delayed for confirmatory testing.

Recent Literature

Review or guideline Migraine review for general practice
Aten Primaria, 2022 · cited 124×

Full text · open access
Recent clinical The ketogenic diet is not for everyone: contraindications, side effects, and drug interactions
Ann Med, 2026 · cited 4×

Full text · open access

5 of 5

Benzodiazepine Dependence and Withdrawal

Benzodiazepine withdrawal can be life-threatening, causing seizures, delirium, autonomic instability, and psychosis. It is especially high risk in patients...

At the Bedside

Pathophysiology: chronic benzodiazepines enhance GABA-A inhibition; abrupt cessation causes CNS hyperexcitability.
Withdrawal timing:
Short-acting agents, e.g., alprazolam/lorazepam: symptoms often within 1–2 days.
Long-acting agents, e.g., diazepam/clonazepam: symptoms may begin several days later.
Symptoms:
Anxiety, insomnia, tremor, diaphoresis, tachycardia, hypertension, nausea, perceptual disturbances.
Severe: seizures, delirium, hallucinations, hyperthermia, rhabdomyolysis.
History:
Agent, dose, duration, last use, source, prior withdrawal seizures.
Co-ingestions or withdrawal from alcohol, barbiturates, baclofen, GHB.
Pregnancy, psychiatric comorbidity, suicidality.
Exam/workup:
Vitals, mental status, tremor, tongue fasciculations, diaphoresis, hallucinations, trauma from seizure/fall.
POC glucose, ECG, pregnancy test when relevant.
CMP/Mg/Phos, CK if seizure/agitation, tox labs if overdose possible.
Consider infection, thyrotoxicosis, sympathomimetic toxicity, serotonin syndrome, and alcohol withdrawal mimics.
ED treatment:
Benzodiazepines are first-line despite being the dependence agent; goal is symptom control and seizure prevention.
Prefer long-acting agents such as diazepam/chlordiazepoxide when appropriate.
Use lorazepam in older adults, significant liver disease, or unreliable enteral absorption.
Treat seizures aggressively with benzodiazepines; refractory cases may need phenobarbital/propofol/intubation.
Avoid flumazenil in benzodiazepine-dependent patients; can precipitate seizures/withdrawal.
Disposition:
Admit/ICU for seizures, delirium, severe autonomic instability, high-dose dependence, polysubstance withdrawal, pregnancy, major comorbidity, unreliable follow-up, or suicidal risk.
Discharge may be appropriate for mild withdrawal with stable vitals, no seizure history, reliable follow-up, and a clear taper plan.
Coordinate addiction medicine/psychiatry/primary care; abrupt discontinuation is dangerous.

A Classic Presentation

A 41-year-old man with daily alprazolam use for years ran out 36 hours ago and presents with severe anxiety, tremor, diaphoresis, tachycardia, hypertension, and visual distortions. He had a prior withdrawal seizure. Glucose is normal, ECG shows sinus tachycardia, and labs show mild hypomagnesemia. He is treated with IV lorazepam, magnesium repletion, seizure precautions, and admitted for monitored benzodiazepine taper.

Study Directive

Memorize short- vs long-acting benzodiazepine withdrawal timelines.
Create a withdrawal severity checklist: vitals, tremor, hallucinations, seizures, delirium, prior complicated withdrawal.
Review your hospital’s alcohol/benzodiazepine withdrawal pathway and phenobarbital policy.
Practice converting a chronic benzodiazepine history into a safe ED disposition and taper/consult plan.

Mechanism Pearl of the Day: Several of today’s emergencies are failures of “pattern recognition without exclusion.” Panic, headache, and AMS can be benign — but SAH, withdrawal, CNS infection, hypoglycemia, and toxicologic states can initially look psychiatric or nonspecific. Mechanistically, many produce sympathetic activation through either CNS irritation, catecholamine surge, hypoxia, or loss of GABA inhibition, so tachycardia/anxiety/diaphoresis should trigger a search for dangerous physiology before reassurance.

Key Medications

Diazepam: 5–10 mg PO/IV every 5–15 min for significant symptoms until calm; longer acting, useful for tapering. Reduce/avoid in severe liver disease or frail older adults.
Lorazepam: 1–2 mg IV/PO/IM every 10–20 min for moderate/severe symptoms; preferred in liver disease/older adults. For seizures: 2–4 mg IV, repeat once.
Chlordiazepoxide: 25–50 mg PO every 6 hr initially for mild/moderate withdrawal/taper; avoid in significant liver disease. Taper regimens vary — check institutional protocol.
Phenobarbital: 130–260 mg IV increments or 10 mg/kg IV load in selected severe/refractory withdrawal; dosing varies meaningfully by protocol and requires monitoring.
Thiamine: 100 mg IV/PO if alcohol use/malnutrition; higher dosing if Wernicke suspected.
Magnesium repletion: e.g., magnesium sulfate 1–2 g IV if low or seizure risk; tailor to labs/renal function.
Do NOT use flumazenil in dependent patients, mixed overdoses, seizure disorder, or TCA co-ingestion.
Pediatric note: benzodiazepine withdrawal can occur in chronically treated children; management is weight-based and often requires PICU/toxicology.

High-Yield Pearls

Benzodiazepine withdrawal resembles alcohol withdrawal because both reflect loss of GABAergic tone and unopposed excitatory neurotransmission.
Alprazolam withdrawal can be particularly severe due to short half-life and high potency.
A “normal” urine benzodiazepine screen does not exclude use; many assays miss clonazepam, alprazolam, and some metabolites.

Board Question

A patient with chronic high-dose alprazolam use presents with tremor, tachycardia, hallucinations, and a generalized seizure after abruptly stopping the medication. Which medication should be avoided?

ALorazepam
BDiazepam
CPhenobarbital
DFlumazenil

Reveal answer

Correct: D

Flumazenil. Flumazenil can precipitate acute withdrawal and seizures in benzodiazepine-dependent patients. Benzodiazepines are the first-line treatment for benzodiazepine withdrawal.

Recent Literature

Review or guideline The benzodiazepine withdrawal syndrome
Addiction, 1994 · cited 241×
Recent clinical Benzodiazepines at the crossroads: navigating therapeutic promise and perils of misuse
Ann Gen Psychiatry, 2026 · cited 1×

Full text · open access

TheDaily Differential

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At the Bedside

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Approach to Altered Mental Status

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Benzodiazepine Dependence and Withdrawal

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