Emergency Medicine: Critically Ill Medical Patients–Study Notes

Case 1: Acute Decompensated Heart Failure (ADHF)

Presentation:

• 67 y/o M, SOB x several days.

• Orthopnea, PND, JVD, leg swelling, crackles.

• Vitals: hypertensive, tachycardic, tachypneic, hypoxic.

Diagnosis:

• Likely CHF exacerbation.

• BNP: mixed utility → useful if very low (rules out CHF), but can be elevated in renal failure, AFib, sepsis, burns, age, obesity, gender.

• More helpful at bedside: ultrasound.

Ultrasound findings:

• B-lines (hyperechoic artifacts).

• 3 B-lines in both lungs = CHF exacerbation.

• Lung ultrasound sensitivity > chest X-ray (88% vs 73%).

Chest X-ray:

• Often ordered but can be normal (20% of ADHF cases).

• Still useful for alternative diagnoses (pneumonia, pneumothorax, COPD signs).

Respiratory Support:

• Non-invasive ventilation (CPAP/BiPAP):

  • Improves work of breathing, reduces intubation risk.

  • Avoid if vomiting or altered mental status.

• High-flow nasal cannula (HFNC):

  • 60 L/min humidified O₂.

  • Studies: slightly higher “failure” (transition to BiPAP), but fewer intubations (–6%).

  • Reasonable to try.

Pharmacologic Therapy:

• Nitrates:

  • First-line. Reduce preload/afterload.

  • Avoid in RV infarct, tamponade, aortic stenosis, PDE-5 inhibitor use (e.g., Viagra).

  • Sublingual → start IV drip → titrate quickly up, then down.

  • Nitro paste unreliable.

• Loop diuretics:

  • Give if fluid overload.

  • Bolus dosing effective; high vs low dose makes little difference.

  • Guideline-supported (ACC/AHA 2013).

• Morphine:

  • Controversial. Evidence: ↑ mortality, ICU admissions, mechanical ventilation. Avoid.

Cardiogenic Shock:

• Identify: hypotension + tachycardia + hypoxia.

• Management:

  • NIPPV for work of breathing.

  • Vasopressors: norepinephrine (MAP >60).

  • Inotropy: dobutamine.

  • Consider balloon pump/advanced support.

Summary (ADHF):

• Nitrates early & aggressive.

• Early NIPPV.

• Give diuretics (dose doesn’t matter much).

• Avoid morphine.

• Support shock with norepi + dobutamine.

Case 2: Severe Asthma Exacerbation

Presentation:

• 37 y/o, severe SOB, wheezing, speaking 1–2 word sentences.

• Prior intubations.

Initial Management:

• Nebulized bronchodilators: continuous albuterol + ipratropium.

• IV steroids: methylprednisolone.

• IV magnesium sulfate:

  • Dose: 2–4 g over 20 min.

  • Evidence: improved peak flow, ↓ admissions.

  • NNT = 2 (very effective).

Adjuncts:

• Epinephrine:

  • IM 0.3 mg (1:1000).

  • Vasoconstricts, reduces edema.

  • Limited benefit vs bronchodilators but reasonable.

• Ketamine:

  • 0.3 mg/kg (max 25 mg).

  • Provides sedation + bronchodilation.

• NIPPV:

  • Can reduce hospitalization.

  • Reasonable trial if tolerated.

• Heliox:

  • Limited benefit unless as delivery agent for meds.

Intubation (last resort):

• Dangerous in asthma (risk of dynamic hyperinflation, barotrauma, tension pneumo).

• Strategy:

  • Preoxygenate (HFNC or NC “apneic oxygenation”).

  • Induction: ketamine + paralytic.

  • Settings:

    • Low rate (6–8 bpm).

    • Long expiratory time (I:E 1:3 or longer).

    • Low PEEP.

  • Allow permissive hypercapnia.

  • Disconnect to relieve auto-PEEP if unstable.

Summary (Severe Asthma):

• Continuous nebs, IV steroids, magnesium.

• Add ketamine, epinephrine as needed.

• NIPPV trial reasonable.

• Avoid intubation unless absolutely necessary.

Case 3: Diabetic Ketoacidosis (DKA)

Presentation:

• 27 y/o, abdominal pain, N/V, polydipsia.

• Hypotension, tachycardia, dry mucous membranes, somnolent.

• Labs: hyperglycemia, metabolic acidosis, low HCO₃.

Initial Management:

• Fluids:

  • Most important initial step.

  • NS or LR boluses.

• Labs:

  • BMP, VBG, UA (ketones), β-hydroxybutyrate.

  • Search for trigger (infection, missed meds, MI).

Potassium is Key (ADA Algorithm):

• <3.5 → replace K⁺, hold insulin.

• 3.5–5 → start insulin, replace K⁺.

• 5 → insulin, no K⁺, recheck frequently.

• Always check Mg²⁺ (needed for K⁺ repletion).

Insulin Therapy:

• Start IV insulin drip 0.1 U/kg/hr.

• No bolus needed.

• Transition: when glucose <250, add dextrose (D5 ½NS) to prevent hypoglycemia while acidosis resolves.

Resolution Criteria:

• Glucose <200 plus two of:

  • Bicarb ≥15

  • pH >7.3

  • Anion gap closed

Summary (DKA):

• Fluids first.

• Delay insulin until K⁺ known.

• Aggressive K⁺ and Mg²⁺ replacement.

• Follow ADA algorithm.

Global Takeaways

• CHF/ADHF: Nitrates, NIPPV, diuretics, avoid morphine. Ultrasound > CXR.

• Asthma: Continuous nebs, steroids, Mg, ketamine, epinephrine. Avoid intubation.

• DKA: Fluids first, check potassium, insulin after K⁺ known, add dextrose when glucose <250.