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🌱 來自: Huppert’s Notes
Diabetic Ketoacidosis (DKA) and Hyperosmolar Hyperglycemic Syndrome (HHS)🚧 施工中
Diabetic Ketoacidosis (DKA) and Hyperosmolar Hyperglycemic Syndrome (HHS)
DKA and HHS are medical emergencies that require prompt triaging, evaluation, and treatment, often in the ICU, due to the need for close monitoring, frequent lab draws, and IV insulin therapy.
Diabetic ketoacidosis (DKA)
• Definition:
- Hyperglycemia (glucose >250 mg/dL), ketonemia, anion gap metabolic acidosis
• Clinical presentation:
- Acute onset with symptoms of hyperglycemia (polyuria, polydipsia)
- GI symptoms: Nausea, vomiting, abdominal pain
- Fatigue, lethargy → coma if severe in later stages
- Hypovolemia: Dry mucous membranes, reduced skin turgor, tachycardia, hypotension if severe
• Etiology:
- Common: Infection, medication nonadherence, insufficient insulin, new-onset type 1 diabetes
- Less common: Acute illness (MI, CVA, pancreatitis), substance use (especially cocaine), glucose pump malfunction, medications (SGLT2i, antipsychotics, steroids)
• Evaluation and diagnostics:
- History: Focused history to determine underlying trigger
- Physical exam: Vital signs, hemodynamic assessment, mental status, volume exam
- Laboratory evaluation: Serum glucose, CBC with differential, BMP (calculate the anion gap), plasma osmolarity, serum ketones (often beta hydroxybutyrate), ABG (or VBG), urinalysis, ECG, CXR, +/− blood and urine cultures if signs of infection, HgA1c
• Management: Follow institutional guidelines if present. General principles are as follows:
- Fluids
• Resuscitation: Patients are volume depleted (deficit often 3–8 L) and require resuscitation; isotonic crystalloids (Plasma-Lyte or NS) given first for volume expansion
• Avoiding hypoglycemia (later in course): When fingerstick glucose (FSG) <250 mg/dL, switch to dextrose-containing solution (often D5 1/2 NS)
- Electrolytes
• Potassium
- Serum potassium can be low, normal, or elevated
• Regardless, patients are total body potassium down if their pH is low
• Both insulin deficiency and acidemia will raise serum potassium
- Insulin administration and correction of acidemia will shift potassium intracellularly and risk hypokalemia and potentially fatal arrhythmias
- Potassium repletion is based on current serum potassium
• If K <3.3 mEq/L, replete K BEFORE giving insulin
• If K 3.3–5.3 mEq/L, then given K (20–40 mEq/L of fluids) and insulin
• If K >5.3 mEq/L, give insulin alone with close trending of serum K
• Magnesium: Replete to >1.6 mg/dL to enable proper K repletion
• Phosphorus: Goal >1.0 mg/dL
• Bicarbonate: Use is not well studied, but can consider if pH <6.9
- Insulin
• Dosing: Intravenous bolus (0.1 units/kg or 5–10 units) and continuous drip (often started at 0.1 units/kg/hr); most institutions have titration protocols for DKA
• Goal: Reduction of FSG by 10% or 50 mg/dL absolute points per hour
- If not achieving goal, can either rebolus or increase gtt rate
• Transitioning from gtt to SQ insulin:
- When FSG <250 mg/dl, reduce gtt rate by 50% (and transition to dextrose containing solution, as noted earlier)
- Determine basal SQ insulin dose
• Note: Patients with DKA have HIGHER insulin needs acutely, often due to stressors such as infection, and thus some methods for estimating insulin needs will overestimate and may risk hypoglycemia
• Total daily dose (TDD) is total insulin needs with roughly 50% given as basal and 50% as prandial
- Method 1: Use home regimen to estimate needs
- Method 2: Weight-based dosing with TDD = 0.5–0.6 units/kg
- Method 3: If patient is on stable, low rate of insulin gtt (ideally <5 units/hr), take total insulin used over the last 6 hours × 4 to estimate TDD. Then take 80% of that calculation for safety purposes (this method will often overestimate insulin needs).
- Combination method: Compare TDD from the methods earlier. If significant discrepancies exist, consider averaging or using the lower, more conservative estimate to avoid hypoglycemia.
- Transition to basal insulin when 1) Anion gap closed; 2) Patient eating; and 3) FSG <250 mg/dL
• Often requires delay until morning or evening to get the patient back on a normal medication schedule
- Continue insulin drip until 1–2 hours AFTER basal SQ insulin dose is given to ensure overlap
- Monitor FSG and labs to ensure anion gap does not reopen
Hyperosmolar hyperglycemic syndrome (HHS)
• Definition: Hyperglycemia (often FSG >600 mg/dL) without ketones or acidemia
• Clinical presentation:
- Often more insidious onset than DKA with days of symptoms
- Symptoms of hyperglycemia: Polyuria, polydipsia
- Hypovolemia: Dry mucous membranes, poor skin turgor, tachycardia, hypotension if severe
- Neurologic symptoms (including seizure and coma in severe cases) arise from high serum osmolarity due to extreme hyperglycemia
• Etiology:
- Can be triggered by infection, medication nonadherence, MI, CVA, substance use, medications (steroids, antipsychotics)
• Evaluation and diagnostics:
- Initial triage, evaluation, and diagnostics are the same as for DKA (see prior section)
- Hemodynamic assessment, neurologic exam, and volume exam are essential
• Management: Principles of treatment and management of HHS are generally the same as in DKA with a focus on adequate and aggressive fluid resuscitation, close monitoring of electrolytes, and IV insulin therapy
- Fluids
• Patients with HHS are typically more profoundly dehydrated than those with DKA and require aggressive IVF resuscitation
• Total body water deficits often approaching 5–10 liters
• Based on corrected sodium, often have residual free water deficit needing hypotonic solutions even after patient is euvolemic
- Electrolytes
• Potassium: In the absence of acidemia, potassium depletion is less pronounced
• Sodium: Hyponatremia from osmotically active glucose pulling in water requires calculating corrected sodium
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• Osmolarity: Patients have hyperosmolarity, which is responsible for neurologic symptoms
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- Resolution of HHS, in addition to correction of electrolyte disturbances and hyperglycemia, includes resolution of any neurologic symptoms and serum osmolarity correction to usually <315 mg/dL
- Insulin
• General insulin management is the same as that for DKA
- Intravenous bolus (0.1 units/kg or 5–10 units) + continuous drip (often started at 0.1 units/kg/hr)
- Follow hospital-specific guidelines for insulin drip management
- For transition from drip to SQ insulin, see the DKA section