AOBEM Emergency Medicine cheat sheet

Acute coronary syndrome: obtain 12-lead ECG within 10 minutes of ED arrival; ST-elevation in two contiguous leads defines STEMI and triggers reperfusion (PCI within 90 min of first medical contact).

Anaphylaxis: epinephrine 0.3-0.5 mg IM (1 mg/mL) into the anterolateral thigh; repeat every 5-15 min as needed; adjuncts (H1/H2 blockers, steroids) never replace epinephrine.

Sepsis: qSOFA (SBP <=100, RR >=22, altered mentation) predicts poor outcome; sepsis with hypotension despite 30 mL/kg crystalloid warrants vasopressors, norepinephrine first-line.

Acute ischemic stroke: IV thrombolysis window 0-4.5 h from last known well; door-to-needle goal <=60 min; exclude hemorrhage by CT before lysis.

Croup vs epiglottitis: barking cough with stridor and steeple sign suggests croup (dexamethasone, nebulized epinephrine); drooling, tripod positioning, and muffled voice suggest epiglottitis (do not agitate the airway).

Boerhaave syndrome: transmural esophageal rupture presents with Mackler triad (vomiting, chest pain, subcutaneous emphysema); contrast study or CT confirms; surgical emergency.

Diabetic ketoacidosis: anion gap = Na - (Cl + HCO3); corrected sodium = measured Na + 1.6 x ((glucose - 100)/100); insulin infusion begins after potassium is >=3.3 mEq/L.

NEXUS criteria for cervical spine imaging: midline tenderness, focal neuro deficit, altered mental status, intoxication, distracting injury - imaging unnecessary only if all five are absent.

START triage: ambulatory patients are green (minor); non-ambulatory without respirations after airway repositioning are black (expectant); apneic with repositioning-assisted breathing or RR >30 are red (immediate).

Destination determination follows the closest appropriate facility principle; trauma triage uses mechanism, anatomy, and physiology (e.g., GCS <=13, SBP <90, RR <10 or >29).

CPR quality targets: compression rate 100-120/min, depth 5-6 cm, full recoil, interruptions <10 s, chest compression fraction >60%.

Defibrillation energy for adult out-of-hospital cardiac arrest: biphasic 120-200 J (manufacturer range); resume compressions immediately after shock without pulse check.

Mass-casualty triage tags: red immediate, yellow delayed, green minor, black deceased/expectant; reassessment occurs at each treatment area.

Scene safety precedes patient contact; hazardous-materials scenes require cold zone treatment and decontamination before transport.

Prehospital 12-lead acquisition with field STEMI activation reduces reperfusion times; transmit to receiving PCI center when available.

EMS documentation elements: dispatch time, response interval, on-scene time, transport interval, and patient care report with interventions and response.

Acetaminophen toxicity: Rumack-Matthew nomogram applies 4 h or more after single acute ingestion; N-acetylcysteine is most effective within 8 h; treat if level exceeds treatment line.

Salicylate toxicity: mixed respiratory alkalosis with anion-gap metabolic acidosis; urine alkalinization (target urine pH 7.5-8) enhances elimination; hemodialysis for severe cases.

Toxic alcohol (methanol, ethylene glycol): elevated osmolal gap early; fomepizole inhibits alcohol dehydrogenase; hemodialysis for significant acidosis or visual/renal injury.

Opioid overdose: naloxone 0.04-0.4 mg IV titrated to respirations; duration may be shorter than the opioid (e.g., methadone), so observe for re-narcotization.

Tricyclic overdose: sodium channel blockade causes QRS >100 ms, terminal R in aVR; sodium bicarbonate 1-2 mEq/kg for QRS widening or ventricular dysrhythmia.

Beta-blocker overdose: glucagon 3-5 mg IV first-line for bradycardia/hypotension; high-dose insulin with dextrose is an alternative in refractory shock.

Digoxin toxicity: hyperkalemia, bradycardia, and yellow-green visual halos; digoxin-specific Fab fragments for life-threatening dysrhythmia or K >5.5 mEq/L.

Carbon monoxide: measure carboxyhemoglobin; 100% oxygen shortens half-life to ~90 min; hyperbaric oxygen for neuro deficits, syncope, or COHb >25%.

Somatic dysfunction is defined by TART: Tissue texture abnormality, Asymmetry, Restriction of motion, and Tenderness.

Counterstrain (positional release): place the tender point in a position of comfort for 90 seconds, then reassess; indirect technique using a monitoring point.

Muscle energy: patient performs isometric contraction against operator resistance for 3-5 seconds, then relaxes; repeat 2-3 times to correct restriction.

High-velocity low-amplitude (HVLA) thrust is contraindicated in unstable cervical spine, vertebral artery insufficiency, and severe osteoporosis; screen for red flags before use.

Visceral referral patterns: gallbladder pain refers to the right scapula and shoulder; diaphragmatic irritation refers to the shoulder tip via the phrenic nerve (C3-C5).

Sympathetic innervation of the heart is T1-T4; upper thoracic somatic dysfunction may accompany angina-like chest pain and must not delay ACS workup.

Lymphatic techniques (thoracic pump, pedal pump) are used adjunctively for edema and congestion; they never substitute for antibiotics or definitive therapy.

Cranial rhythmic impulse is assessed at 6-12 cycles per minute; cranial techniques are contraindicated with acute intracranial hemorrhage or elevated ICP.

Rapid sequence intubation: preoxygenate, give induction agent, then paralytic (succinylcholine 1.5 mg/kg or rocuronium 1.2 mg/kg); confirm with waveform capnography.

Tension pneumothorax is a clinical diagnosis: unilateral absent breath sounds, tracheal deviation, and hypotension; treat with immediate needle decompression before imaging.

PE workup: Wells score with PERC to rule out; D-dimer for low/intermediate probability; CT pulmonary angiography for high probability or positive D-dimer.

Hyperkalemia with ECG changes: IV calcium to stabilize the myocardium, insulin with glucose and albuterol to shift potassium, then elimination via diuresis or dialysis.

Pediatric weight estimation: 2 x (age in years) + 8 kg; pediatric defibrillation energy is 2 J/kg for the first shock and 4 J/kg for subsequent shocks.

Head trauma anticoagulated patients: a normal CT does not exclude delayed hemorrhage; observe or repeat imaging, and reverse anticoagulation when indicated.

Ludwig angina: bilateral submandibular swelling with tongue elevation threatening the airway; requires early airway control and IV antibiotics covering oral flora.

Ovarian torsion and testicular torsion are time-critical surgical emergencies; do not delay surgical consultation for imaging when clinical suspicion is high.

Medical direction types: online (direct radio/phone orders) versus offline (standing protocols and medical director oversight).

Air medical transport criteria include prolonged extrication, inaccessible terrain, and time-dependent surgical needs where ground transport exceeds the benefit of air.

Hypothermia cardiac arrest: withhold epinephrine until core temperature is above 30 C and consider prolonged resuscitation with rewarming; 'not dead until warm and dead'.

Pediatric airway sizing: uncuffed ET tube size = (age/4) + 4 mm; cuffed tube = (age/4) + 3.5 mm.

Prehospital stroke screening (Cincinnati: facial droop, arm drift, speech) triggers transport to a stroke center with pre-arrival notification.

Tourniquet application for extremity hemorrhage: place 2-3 inches proximal to the wound, tighten until bleeding stops, and document time applied.

Mass-casualty incident command uses the incident command system: triage, treatment, transport, and staging are separate functional areas.

EMS refusal of care requires documented capacity assessment, informed refusal, and medical direction involvement when risk is significant.

Toxidrome recognition: anticholinergic (dry, hot, flushed, mydriasis), cholinergic (SLUDGE plus bradycardia), sympathomimetic (tachycardia, hypertension, diaphoresis), opioid (miosis, respiratory depression).

Organophosphate poisoning: atropine titrated to drying of secretions; pralidoxime reactivates acetylcholinesterase and is most effective before aging.

Methemoglobinemia: cyanosis unresponsive to oxygen, chocolate-brown blood, and saturation gap; treat with methylene blue 1-2 mg/kg IV.

Iron overdose: vomiting, GI bleeding, and anion-gap acidosis; deferoxamine chelation for severe toxicity; abdominal radiograph may show radiopaque pills.

Cyanide toxicity: lactic acidosis with normal PaO2 and bitter-almond odor; hydroxocobalamin binds cyanide and is preferred in smoke inhalation.

Serotonin syndrome: clonus, hyperreflexia, and agitation after serotonergic agents; cyproheptadine is an antidote; avoid antipyretics alone.

Alcohol withdrawal: symptom-triggered benzodiazepines guided by CIWA-Ar; thiamine before glucose to prevent Wernicke encephalopathy.

Lithium toxicity: tremor, ataxia, and nephrogenic diabetes insipidus; hemodialysis for severe levels, renal failure, or neurologic toxicity.

Facilitated positional release adds a neutral position (usually flexion) before the comfort position, reducing the hold time to about 3 seconds.

Strain-counterstrain tender points are named for their associated muscle (e.g., anterior tender points of the cervical spine relate to the sternocleidomastoid).

Myofascial release uses sustained light traction until a release is felt; it is a direct technique applied to fascial restrictions.

Chapman points are anterior Chapman reflex points used diagnostically for visceral dysfunction; treatment is circular massage for 10-30 seconds.

Rib somatic dysfunction: exhalation dysfunction treats with a springing force during exhalation; inhalation dysfunction treats with a springing force during inhalation.

Sacral diagnosis: seated flexion test and sacral sulcus symmetry determine torsion direction; L5 mechanics influence sacral motion.

Cervical HVLA contraindications include rheumatoid arthritis with atlantoaxial instability, Down syndrome, and recent whiplash with ligamentous injury.

Osteopathic structural exam in the ED: document segmental dysfunction before and after OMT to demonstrate response and avoid masking a surgical abdomen.

Acute asthma: continuous albuterol, ipratropium, and systemic corticosteroids; magnesium sulfate 2 g IV for severe exacerbation; consider ketamine or epinephrine for near-fatal.

Hypoglycemia: point-of-care glucose, then D50 25 g IV or glucagon 1 mg IM if no IV access; recheck glucose after treatment.

Aortic dissection: sudden tearing chest pain radiating to the back with pulse deficit; obtain CT angiography; give beta-blockade before vasodilators.

Ectopic pregnancy: quantitative beta-hCG with transvaginal ultrasound; empty uterus with beta-hCG above the discriminatory zone requires surgical evaluation.

Status epilepticus: benzodiazepines first-line (lorazepam 0.1 mg/kg IV), then fosphenytoin or levetiracetam; refractory cases need intubation and continuous infusion.

Necrotizing fasciitis: pain out of proportion, crepitus, and rapid spread; immediate surgical debridement plus broad-spectrum antibiotics including clindamycin.

Appendicitis: Alvarado score combines migration, anorexia, nausea, tenderness, rebound, fever, and leukocytosis; CT is the preferred imaging in adults.

Upper GI bleed: Glasgow-Blatchford score guides disposition; IV proton-pump inhibitor and endoscopy within 24 h; transfuse for hemoglobin <7 g/dL.

Triage sieve versus sort: the sieve assigns categories rapidly, then the sort refines treatment priorities for transport.

Burn triage: estimate total body surface area with the rule of nines; patients with >20% TBSA, inhalation injury, or circumferential burns need burn-center transfer.

Spinal motion restriction is indicated for suspected unstable injury; use a rigid collar with backboard only for extrication and remove the board promptly to prevent pressure injury.

Field analgesia options include fentanyl and ketamine; ketamine at subdissociative doses provides analgesia with preserved airway reflexes.

Prehospital sepsis alert criteria commonly include two or more SIRS criteria plus suspected infection to trigger early notification and antibiotics.

Automated external defibrillator use in children: use pediatric pads and attenuator when available; otherwise use adult pads with anterior-posterior placement.

Documentation of refusal must include the risks explained, the patient's stated understanding, and the signature of the patient or surrogate.

Mutual aid and mass-gathering planning: estimate patient volume from crowd size and event risk, and pre-position medical assets accordingly.

Activated charcoal 1 g/kg is most useful within 1 hour of ingestion; contraindicated with unprotected airway, GI obstruction, or caustic ingestion.

Calcium channel blocker overdose: IV calcium salts, glucagon, and high-dose insulin euglycemia therapy; vasopressors for refractory hypotension.

Sulfonylurea-induced hypoglycemia: octreotide suppresses insulin release; dextrose alone risks recurrent hypoglycemia.

Hydrocarbon ingestion: risk of aspiration pneumonitis; avoid gastric lavage and emesis; observe for respiratory symptoms.

Body packer versus body stuffer: packers carry wrapped packets and risk obstruction or rupture; whole-bowel irrigation with polyethylene glycol is used for packets.

Anticholinergic toxicity from Jimson weed or diphenhydramine: physostigmine is reserved for severe delirium with intact cardiac conduction.

Warfarin overdose: elevated INR without bleeding is observed or given vitamin K; major bleeding requires four-factor PCC plus vitamin K.

Heating and smoke inhalation: suspect cyanide and carbon monoxide co-toxicity; give hydroxocobalamin and 100% oxygen empirically.

Spencer technique is a sequence of shoulder and upper extremity articulation used for adhesive capsulitis and shoulder restriction.

Thoracic outlet syndrome evaluation includes Adson, Roos, and Wright tests; OMT targets scalene and pectoralis restriction.

Piriformis syndrome: tenderness over the piriformis with positive FAIR or Freiberg test; muscle energy and counterstrain target the muscle.

Sacroiliac dysfunction: standing flexion test and ASIS compression; innominate rotations are treated with muscle energy or HVLA.

Lymphatic pump contraindications include acute cellulitis, DVT, and decompensated heart failure; use cautiously with infection.

Somatic dysfunction of the lower thoracic spine can mimic biliary or renal colic; always exclude emergent causes before attributing pain to musculoskeletal origin.

Cranial bone motion assessment: sphenobasilar synchondrosis motion is evaluated for flexion and extension; treat gently in infants and the elderly.

Osteopathic manipulative treatment coding: document the specific technique (e.g., muscle energy, HVLA) and the body region treated for accurate billing.

Chest pain risk stratification: HEART score (history, ECG, age, risk factors, troponin) with 0-3 low risk suitable for accelerated discharge pathways.

Pulmonary edema: noninvasive positive-pressure ventilation reduces intubation rates; nitroglycerin is first-line for hypertensive pulmonary edema.

Syncope: San Francisco Syncope Rule and Canadian Syncope Risk Score guide admission; ECG and orthostatic vitals are mandatory.

Compartment syndrome: pain with passive stretch, tense compartment, and paresthesia; measure compartment pressure and consult surgery urgently.

Rabies and tetanus prophylaxis: tetanus booster for contaminated wounds if >5 years since last dose; rabies immunoglobulin plus vaccine for high-risk exposures.

Intussusception in children: colicky pain, currant-jelly stool, and target sign on ultrasound; air or contrast enema is both diagnostic and therapeutic.

Hypothermic patients: use a low-reading thermometer; rewarm actively for moderate to severe hypothermia and handle gently to avoid dysrhythmia.

Acute urinary retention: bladder scan volume, then urethral catheterization; if urethral fails, suprapubic catheterization by trained personnel.

Emergency medical dispatch uses scripted protocols to determine response priority and give pre-arrival instructions such as CPR and hemorrhage control.

Helicopter safety: approach only when signaled, stay clear of the tail rotor, and secure loose equipment before loading.

Pediatric assessment triangle (appearance, work of breathing, circulation) guides rapid prehospital triage of the sick child.

Prehospital hypothermia prevention includes warming blankets, warmed IV fluids, and removing wet clothing during transport.

Protocol for crush injury: fluids, analgesia, and early transport; monitor for compartment syndrome and rhabdomyolysis.

Continuous quality improvement in EMS uses response-time benchmarks, cardiac arrest registry data, and case review with medical direction.

Stroke and STEMI diversion protocols allow bypass of closer hospitals for specialty centers when transport time criteria are met.

Scene time for trauma patients should be minimized; load-and-go for unstable patients with hemorrhage or airway compromise.

Anion gap metabolic acidosis mnemonic: MUDPILES (methanol, uremia, DKA, propylene glycol, isoniazid, lactic acidosis, ethylene glycol, salicylates).

Osmolal gap = measured osmolality - calculated osmolality (2Na + glucose/18 + BUN/2.8); a gap >10 suggests an unmeasured osmole.

Naloxone dosing in opioid-dependent patients should be titrated to avoid precipitated withdrawal; start low and repeat.

Isoniazid overdose causes seizures refractory to standard therapy; pyridoxine (vitamin B6) is the antidote.

Lead poisoning: abdominal colic, anemia with basophilic stippling, and encephalopathy; chelate with EDTA or succimer for severe cases.

Clonidine overdose: miosis, bradycardia, and hypotension; naloxone may reverse some effects; supportive care is mainstay.

Ethanol intoxication: supportive care with thiamine and glucose; check for co-ingestions and trauma before attributing altered mental status to alcohol.

Antidote for benzodiazepine overdose: flumazenil is avoided in chronic users and mixed overdoses due to seizure risk; supportive care is preferred.

Cervical counterstrain tender points: anterior points treat with extension and sidebending; posterior points treat with flexion and rotation.

Rib raising is an indirect technique that improves thoracic mobility and lymphatic drainage; useful adjunct in pneumonia and COPD.

Muscle energy for the thoracic spine uses seated patient positioning with respiratory assistance to improve rib and vertebral motion.

Viscerosomatic reflexes: cardiac T1-T4, stomach T5-T9, gallbladder T5-T9 right, appendix T10-T12 right, and pelvic organs T10-L2.

Contraindications to OMT include acute fracture, dislocation, malignancy at the site, and unstable medical conditions.

Cranial technique is used cautiously in infants for plagiocephaly and in adults for headache; evidence is limited and adjunctive.

Somatic dysfunction of the cervical spine can produce vertigo; exclude posterior circulation stroke before treatment.

Post-OMT reassessment documents changes in tissue texture, motion, and tenderness to confirm treatment response.

Trauma primary survey: airway with cervical spine protection, breathing, circulation with hemorrhage control, disability, and exposure.

Massive transfusion protocol: balanced ratios of plasma to platelets to red cells (approximately 1:1:1) with tranexamic acid within 3 hours of injury.

Intracranial hemorrhage: reverse anticoagulation rapidly; warfarin with four-factor PCC and vitamin K; DOACs with specific reversal agents.

Acute mesenteric ischemia: pain out of proportion with elevated lactate; CT angiography is diagnostic; early surgical consultation.

Thyroid storm: Burch-Wartofsky score; treat with beta-blocker, thionamide, iodine after thionamide, and steroids.

Adrenal crisis: hypotension refractory to fluids; give hydrocortisone 100 mg IV empirically when suspected.

Necrotizing soft tissue infection: LRINEC score supports but does not replace clinical judgment; surgical exploration is definitive.

Pediatric dehydration: ORT for mild-moderate; IV bolus 20 mL/kg for shock; reassess after each bolus.

Defibrillator pad placement: anterolateral or anteroposterior; ensure dry chest and remove transdermal patches before application.

Post-ROSC care: target oxygen saturation 94-98%, avoid hyperventilation, obtain 12-lead ECG, and transport to a cardiac arrest center.

Pediatric CPR ratio is 30:2 for single rescuer and 15:2 for two rescuers; push hard and fast with full recoil.

Prehospital pain assessment uses a validated scale (numeric or Wong-Baker) and reassessment after each analgesic dose.

Airway management: supraglottic devices are alternatives when intubation fails; confirm placement with waveform capnography.

Triage during a mass-casualty incident: reassess patients at each treatment area because categories can change with deterioration.

Documentation of medication administration includes dose, route, time, indication, and patient response.

EMS research and protocol updates follow evidence-based guidelines from national organizations and local medical direction.

Toxidrome for sympathomimetic: tachycardia, hypertension, mydriasis, diaphoresis, and agitation; benzodiazepines are first-line for agitation.

Cholinergic crisis: SLUDGE plus bronchorrhea and bradycardia; atropine for symptomatic bradycardia and secretions.

Ethylene glycol toxicity: oxalate crystals in urine, renal failure, and hypocalcemia; fomepizole and hemodialysis.

Methanol toxicity: visual disturbances and severe anion-gap acidosis; fomepizole and hemodialysis.

Acetaminophen toxicity: check level 4 hours after ingestion; NAC is continued if level above the treatment line; consider liver transplant for fulminant failure.

Salicylate toxicity: avoid intubation unless necessary because it can worsen acidosis; use bicarbonate and hemodialysis.

Iron toxicity: deferoxamine for serum iron >500 mcg/dL with symptoms or >800 mcg/dL regardless of symptoms.

Beta-blocker and calcium channel blocker overdose: high-dose insulin euglycemia therapy improves inotropic support in refractory shock.

Somatic dysfunction of the thoracic spine can refer pain to the chest wall; always obtain ECG to exclude cardiac ischemia before OMT.

Lymphatic pump technique is performed with rhythmic thoracic and pedal pumping to enhance venous and lymphatic return.

Counterstrain for the low back uses flexion and rotation to shorten the affected muscle; hold 90 seconds and reassess.

Muscle energy for the cervical spine uses isometric contraction in rotation and sidebending to improve motion.

HVLA for the lumbar spine requires proper positioning and a short, controlled thrust; avoid in acute fracture or severe osteoporosis.

Visceral techniques address motility and mobility of organs; they are adjunctive and never replace emergency evaluation.

Documentation of OMT includes the segmental diagnosis, technique used, and post-treatment findings.

Contraindications to lymphatic techniques include acute infection, DVT, and decompensated heart failure.

Acute abdominal pain in the elderly: lower threshold for imaging and surgical consultation because presentation is atypical and mortality is higher.

Testicular torsion: do not delay detorsion for ultrasound when clinical suspicion is high; manual detorsion can be attempted.

Ovarian torsion: sudden severe unilateral pelvic pain with nausea; Doppler may be normal; surgical evaluation is definitive.

Acute angle-closure glaucoma: painful red eye with fixed mid-dilated pupil and halos; immediate ophthalmology and IOP-lowering agents.

Central retinal artery occlusion: sudden painless vision loss with cherry-red spot; treat as stroke and obtain urgent ophthalmology evaluation.

Epistaxis: anterior bleeding from Kiesselbach plexus; apply pressure and cautery; posterior bleeding may require packing and ENT.

Dental avulsion: replant permanent tooth within 60 minutes, handle by crown, and store in milk or saline.

Necrotizing fasciitis: immediate surgical debridement plus broad-spectrum antibiotics with clindamycin for toxin suppression.