Diabetic ketoacidosis

Background

• Hyperosm and insulin deficiency > hyperkalemia
  • As reverses K+ goes back into cell
• Most pts 3-6L depleted
• Look for causes:
  • Insulin non-compliance
  • Infection
  • Ischemia
  • Intra-abd process
  • Iatrogenic (steroids)
  • ETOH/drug abuse

Workup

• CBC
• Chem 10
• UA
• Serum ketones
• hCG
• ECG
• ?VBG
• ?CXR

Treatment

Classification

1. Mild (ketosis): gap <12
2. Mod: gap 12-18
3. Severe: gap >18

Initial

• Labs
  • Glucose check Q1hr
  • Chem 10 Q4hr
  • Corrected Na:
    • Add 1.6 for each glucose of 100 >100
• Fluids
  • If severe hypovolemia: 1L NS / hr for up to 3 hr
  • If mild dehydration then evaluate corrected Na+
    • If hypernatremic: 1/2NS @ 250-500ml/hr
    • If hyponatremic: NS @ 250-500ml/hr
  • When BS < 200 switch to D51/2NS@ 150-200 ml/hr(+/- KCl)
  • Bolus NS as needed for unstable VS
• Insulin
  • Check K prior to insulin Tx!
    • If K < 3.3 do not administer insulin
  • IV Route
    • IV gtt 0.14 U/kg/hr = 10 U/hr in 70kg pt
      • Bolus dose unnecessary
    • If BS does not decrease by 50-70/hr then double infusion rate qhr until achieved
    • When BS <200, reduce to 0.02-0.05 U/kg/hr IV OR give subQ 0.1 U/kg q2hr
      • Maintain BS between 150 and 200 until resolution of DKA
  • SubQ route (appropriate only for mild DKA)
    • Insulin lispro or aspart 0.3 U/kg initially
      • 0.2 U/kg one hr later
        • 0.2 U/kg q2hr thereafter
    • If BS does not decrease by 50-70/hr then double dose qhr until achieved
• Potassium (initial)
  • >5.5: don't give, but recheck q2hr
  • 3.3-5.5: give 30 meq/hr in each liter bag
    • 1/2NS is preferred b/c adding 30meq to NS = hypertonic soln
  • <3.3: hold insulin and give 30 meq/hr until K >3.3
• Bicarb
  • if pH <6.9: 100 meq NaHCO3 in 400mL H2O @ 200 mL/hr
    • Dose as needed until pH > 7.00
• Phosphate
  • Repletion is controversial
    • Hypophosphatemia following insulin tx usually asymptomatic
      1. Repletion is associated with hypoCa and hypoMg
  • Consider repletion (KPO4 20-30 meq/L)if:
    • Phosphate <1.0
    • Cardiac dysfunction
    • Respiratory dysfunction
    • Evidence of hemolysis or rhabdo

Secondary

• When gap closes and patient able to eat:
  • Begin multidose insulin regimen
  • Continue IV infusion for 1-2 hr after SC insulin tx is begun

Complications

• Cerebral Edema
  • Almost all affected pts are <20yrs
  • Associated with initial bicarb, not rate of glucose drop
• Noncardiogenic pulmonary edema

Sliding Scale

• 200-250 = 4u sq
• 251-300 = 6
• 301-350 = 8
• 351-400 = 10

Source

Adapted from Chavira, Rosen, Mistry, Ip, Donaldson, Pani, UpToDate