Diabetic ketoacidosis

Background

Hyperosmolality and insulin deficiency causes hyperkalemia; as reverses K+ goes back into cell

Most pts 3-6L depleted

Look for precipitating causes:

1. Insulin non-compliance
2. Infection
3. Ischemia
4. Intra-abd process
   1. (Lipase/amylase not specific in pts w/ DKA)
5. Iatrogenic (steroids)
6. Etoh/drug abuse

Workup

PRECIPITANT

Fever is rare even in the presence of infection due to peripheral vasoconstriction 2/2 hypovolemia

1. CBC
2. Chem 10
3. Urine acetone/b-OH
   1. If urine ketones + then obtain serum ketones
4. Plasma osmolality
5. hCG
6. UA
7. ECG
8. ?VBG
9. ?CXR

Treatment

Classification

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

Initial

1. Labs
   1. Glucose check Q1hr
   2. Chem 10 Q4hr
   3. Corrected Na+
      1. Add 1.6mEq for each glucose 100mg/dl >100)
2. IV Fluids
   1. If severe hypovolemia: 1L NS / hr for up to 3 hr
   2. If mild dehydration then evaluate corrected Na+
      1. If hypernatremic: 1/2NS @ 250-500ml/hr
      2. If hyponatremic: NS @ 250-500ml/hr
   3. When BS < 200 switch to D5½NS@ 150-200 ml/hr(+/- KCl)
   4. Bolus NS as needed for unstable VS
3. Insulin
   1. Check K+ prior to insulin Tx!
      1. If K < 3.3 do not administer insulin
   2. IV Route
      1. IV gtt 0.14 U/kg/hr =10 U/hr in 70kg pt
         1. Bolus dose unnecessary
      2. If BS does not decrease by 50-70/hr then double infusion rate qhr until achieved
      3. When BS <200, reduce to 0.02-0.05 U/kg/hr IV OR give subQ 0.1 U/kg q2hr
         1. Maintain BS between 150 and 200 until resolution of DKA
   3. SubQ route (appropriate only for mild DKA)
      1. Insulin lispro or aspart 0.3 U/kg initially
         1. 0.2 U/kg one hr later
            1. 0.2 U/kg q2hr thereafter
      2. If BS does not decrease by 50-70/hr then double dose qhr until achieved
4. Potassium (initial)
   1. >5.5: don't give, but recheck q2hr
   2. 3.3-5.5: give 30 meq/hr in each liter bag
      1. 1/2NS is preferred b/c adding 30meq to NS = hypertonic soln
   3. <3.3: hold insulin and give 30 meq/hr until K >3.3
5. Bicarb
   1. if pH <6.9: 100 meq NaHCO3 in 400mL H2O @ 200 mL/hr
      1. Dose as needed until pH > 7.00
6. Phosphate
   1. Repletion is controversial
      1. Has not been shown to be beneficial
      2. Hypophosphatemia following insulin tx usually asymptomatic
      3. Repletion is associated with hypoCa and hypoMg
   2. Consider repletion (KPO4 20-30 meq/L)if:
      1. Phosphate <1.0
      2. Cardiac dysfunction
      3. Respiratory dysfunction
      4. Evidence of hemolysis or rhabdo

Secondary

When gap closes and patient able to eat:

1. Begin multidose insulin regimen
2. Continue IV infusion for 1-2 hr after SC insulin tx is begun

Complications

• Cerebral Edema
  • Almost all affected pts are <20yrs
• Noncardiogenic pulmonary edema

SLIDING SCALE

200- 250- 4u sq

251- 300- 6

301- 350- 8

351- 400- 10

> 400- call MD

Source

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