Initial assessment and risk stratification

Initial assessment and risk stratification

Initial assessment and risk stratification

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Initial Assessment - First Look, Fast!

  • ABCs First! Secure airway, ensure adequate breathing & circulation.
    • Consider intubation for comatose patients (GCS < 8).
    • Establish two large-bore IV lines for fluid resuscitation.
  • Vitals & Key Signs:
    • Hypotension & Tachycardia suggest severe dehydration.
    • Kussmaul respirations (deep, rapid breathing).
    • Fruity (acetone) breath odor.
  • Immediate Diagnostics:
    • Fingerstick glucose: Confirms hyperglycemia (typically > 250 mg/dL).
    • STAT Labs: VBG/ABG, CMP, serum ketones (β-hydroxybutyrate), urinalysis.
  • Anion Gap: Calculate using $Na^+ - (Cl^- + HCO_3^-)$.
  • Risk Stratification (High Risk):
    • Severe acidosis: pH < 7.1 or HCO₃⁻ < 10 mEq/L.
    • Altered mental status (cerebral edema risk).
    • Critical K⁺ levels: < 3.3 or > 5.2 mEq/L.

⭐ An elevated anion gap (> 12 mEq/L) is a hallmark of DKA and is essential for monitoring therapy until the gap closes.

Pathophysiology of DKA and HHS

Diagnostic Criteria - The DKA Triangle

DKA is defined by three core metabolic derangements. All three must be present for a definitive diagnosis.

  • Hyperglycemia
    • Blood glucose > 250 mg/dL (13.9 mmol/L).
  • Ketosis
    • Presence of ketones in urine or serum.
    • Serum beta-hydroxybutyrate is more specific and preferred.
  • Metabolic Acidosis
    • Arterial pH < 7.3.
    • Serum bicarbonate < 18 mEq/L.
    • Elevated anion gap: $AG = Na^+ - (Cl^- + HCO_3^-)$ > 12.

Euglycemic DKA: Remember that DKA can occur with glucose < 250 mg/dL, classically in patients taking SGLT2 inhibitors, in pregnancy, or with poor oral intake.

Risk Stratification - Sorting the Sick

  • Mild DKA

    • Arterial pH: 7.25-7.30
    • Serum Bicarbonate: 15-18 mEq/L
    • Anion Gap: >10
    • Mental Status: Alert
  • Moderate DKA

    • Arterial pH: 7.00-7.24
    • Serum Bicarbonate: 10-14 mEq/L
    • Anion Gap: >12
    • Mental Status: Alert/Drowsy
  • Severe DKA

    • Arterial pH: <7.00
    • Serum Bicarbonate: <10 mEq/L
    • Anion Gap: >12
    • Mental Status: Stupor/Coma
  • Key Formula:

    • $Anion~Gap = [Na^+] - ([Cl^-] + [HCO_3^-])$
    • Normal AG is 4-12 mEq/L.

High-Yield: As the anion gap closes during treatment, a normal anion gap metabolic acidosis (hyperchloremic) may emerge due to IV fluid chloride content and renal bicarbonate loss. This is typically transient.

High‑Yield Points - ⚡ Biggest Takeaways

  • Initial assessment prioritizes ABCDEs, volume status, and mental status evaluation.
  • Crucial initial labs include blood glucose, serum ketones (β-hydroxybutyrate), and an anion gap metabolic acidosis calculation.
  • An ECG is vital to assess for hyperkalemia (peaked T waves) and rule out ischemic triggers.
  • Identify and treat precipitating causes like infection (most common), MI, or insulin non-compliance.
  • Severe DKA is marked by pH <7.0, bicarbonate <10 mEq/L, or altered mental status.

Practice Questions: Initial assessment and risk stratification

Test your understanding with these related questions

A 19-year-old man with a history of type 1 diabetes presents to the emergency department for the evaluation of a blood glucose level of 492 mg/dL. Laboratory examination revealed a serum bicarbonate level of 13 mEq/L, serum sodium level of 122 mEq/L, and ketonuria. Arterial blood gas demonstrated a pH of 6.9. He is admitted to the hospital and given bicarbonate and then started on an insulin drip and intravenous fluid. Seven hours later when his nurse is making rounds, he is confused and complaining of a severe headache. Repeat sodium levels are unchanged, although his glucose level has improved. His vital signs include a temperature of 36.6°C (98.0°F), pulse 50/min, respiratory rate 13/min and irregular, and blood pressure 177/95 mm Hg. What other examination findings would be expected in this patient?

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Flashcards: Initial assessment and risk stratification

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Which part of medicare provides basic medical bills (e.g. doctor's fees, diagnostic testing)? _____

TAP TO REVEAL ANSWER

Which part of medicare provides basic medical bills (e.g. doctor's fees, diagnostic testing)? _____

Part B

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