Guidelines for management of DKA

Classification of DKA

Management

1. Initial Volume Expansion/Fluid Resuscitation
• Give 10 cc/kg 0.9% NaCl over 20 to 60 minutes (may need to be given faster).
2. Poor perfusion, hypotension, or shock
• Give 20 cc/kg 0.9% NaCl over 20 to 60 minutes (time depends on amount of compromise)
• REASSESS
• If patient still shocky, give another 20 cc/kg NaCl over 20 to 60 minutes
• REASSESS
• Most patients will not require more than 20 cc/kg NaCl for initial rehydration, however some patients will need more.
• Frequent reassessment of patient's status will help guide fluid therapy.  Too little fluid will hinder resolution of shock and acidosis, too much fluid may contribute to the development of cerebral edema.
• Often, very high glucose levels (> 500) and BUN > 30 mg/dL are indicative of severe dehydration.

Maintenance IV fluids and rehydration

1. Maintenance = 1500 to 2000 cc/m²/day or use cc/kg body weight (refer to Harriet Lane Handbook).  May need to increase if patient is febrile or hyperventilating. 
2. For deficit replacement, assume at least a 10% dehydration (100 cc/kg) at admission.
3. Give maintenance fluids plus 1/2 of deficit in the first 24 hours, and plan to replace total deficit over 48 hours.  Include PO intake.
4. Most suitable replacement fluid is 0.45% NaCl with 20 - 40 mEq/L potassium.  Give potassium usually as half KCl and half K₂HPO₄ (dibasic potassium phosphate) or K₃PO₄ (if dibasic form unavailable). 
• If initial K⁺ is > 6 mEq/L, do not add K⁺ to the IV fluid.
• Monitor K⁺ frequently and add K⁺ to IV fluids when K⁺ has fallen to less than 5 mEq/L range and patient urinating.  Use 10 - 40 mEq/L K⁺ depending on patients duration of symptoms and serum K⁺.  The vast majority of patients will need 40 mEq/L K+ (see potassium section for more details).
5. Assess intake and output hourly until stable.  If there are excessive fluid losses (via GI or urine) you may need to increase IV rate above initialy calculated rate.
6. Remember that hyponatremia can be can be artificial in the face of severe hyperglycemia and hyperlipidemia.  Sodium declines 1.6 mEq/L for every 100 mg/dL 
 

Example:  Na+ is 127 mEq/L, glucose is 600 mg/dL.  True Na+ is 600 - 100 = 500  5 x 1.6 = 8 mEq/L  True Na+ concentration = 127 + 8 = 135 mEq/L

 

Insulin

1. Begin fluid resuscitation prior to initiation of insulin.
2. Start insulin infusion as 0.1 units/kg/hour.  No need to give an IV bolus.
3. Mix insulin in 0.9% NaCl (equals 1 unit/cc), and flush tubing with 25 cc of insulin drip prior to use.  Insulin should be administered via medfusion syringe pump.
4. Maximum insulin infusion should not exceed 5 units/hour, unless approved by PICU attending physician.
5. If no improvement in pH or HCO₃^- is noted by 4 hours of 0.1 units/kg/hour, increase insulin drip.  Consult PICU attending before making an adjustment in IV insulin drip.
6. With insulin infusion and IV replacement, glucose should decline 75-100 mg/dL/hour.  With the initial volume expansion, the glucose may fall to 300 mg/dL in the first hour secondary to extracellular volume expansion. 
7. Once blood glucose declines to about 200 - 250 mg/dL, add 5% dextrose to the IV solution to avoid hypoglycemia.  DO NOT DECREASE THE INSULIN DRIP UNLESS THE pH, HCO₃^-, AND KETONES are improving.  Do not use glucose concentrations above D₅ without contacting the PICU attending. 
8. The pH and HCO₃^- should normalize within 8 to 12 hours of therapy.  Ketonemia and ketonuria may continue for 24 hours.  If pH and HCO₃^- have improved (pH > 7.30 and HCO₃^- > 15) and the glucose is in the 150 - 250 range with D₅ in the IV solution, the insulin drip may be decreased to 0.03 to 0.05 units/kg/hour. 
9. Once the patient is taking PO, pH and HCO₃^- have normalized, and ketones are clearing you may consider transitioning the patient from continuous IV insulin to a subcutaneous regimen.  Consult the Endocrinology attending for the transition regimen.  The usual approach is to give 0.1 to 0.2 units per kg of regular insulin, subcutaneously, preferably around a meal time such as breakfast.  Stop the IV glucose but keep the insulin drip running for 15 minutes after subcutaneous insulin is given.  Then discontinue insulin drip and give the patient a meal.  Once transitioned to subcutaneous insulin, the patient can be transferred to the pediatric floor.  There is no need to overlap the IV and SC insulin, provided blood glucose is around 150 mg/dL.  The transition patients, use Humalog instead or regular insulin, if available.

Dextrose

1. Add D₅ to IV fluid when blood glucose is around 250 mg/dL.
2. Remember that the goal of therapy is to resolve ketoacidosis.  If blood glucose is not falling and ketoacidosis is not improving, either dehydration is still present, more insulin is required, or infusion may not be correct.
3. If the glucose is falling more than 150 mg/dL per hour, recheck the dilution of the insulin drip to make sure it is correct.  If so, the dose should be changed to 0.05 to 0.075 units/kg/hour to prevent rapid decline in glucose concentration.  Remember, if the acidosis is not clearing but glucose is dropping in the patient, you need to consider increasing the concentration of glucose rather than decreasing the insulin drip.  Glucose concentration of more than 5% should not be used without contacting the PICU attending first.
 

Electrolytes and bicarbonate

Potassium

• The patient has a total body K⁺ depletion regardless of the initial serum K⁺.
• Correction of acidosis and the use of insulin and glucose cause intracellular shift of K⁺ and decline of serum K⁺.
• If the patient is in renal failure or if the serum K+ is greater than 5 mEq/L, withhold K⁺ from initial IV fluids.  Remember that the serum creatinine can be falsely reported as high by the lab in severe DKA.  If no K⁺ is added initially, monitor K+ carefully as it can fall precipitously as DKA is treated.  Add K⁺ to IV solution when K⁺ is 5.0 mEq/L and the patient is urinating.
• Available potassium salts include KH₂PO₄, KCl and K₂HPO₄.  Dibasic potassium phosphate, K₂HPO₄, is the preferred salt at GUH.
• Hypokalemia (K less than 3.5 mEq/L) is dangerous because of the possibility of cardiac arrhythmias.  If the patient is hypokalemic, consider increasing the K⁺ to 60 to 80 mEq/L in the IV fluids (this is a lot of K⁺ and probably requires a central line -- do not do this without talking to the PICU attending first -- also see general guidelines for the use of intravenous potassium ).  The making of glycogen from glucose also enhances potassium entry into cells, therefore if hypokalemia develops, keep glucose-containing IV fluids at less than 100 cc/m2/hour.  You may need to decrease the concentration of glucose in the IV fluids to 2.5%.

Phosphate

• PO₄ depletion occurs because of acidosis and urinary losses.  This can lead to decreased ATP and 2,3 DPG levels.
• Usually give 10-20 mEq/L PO₄ as K₂HPO₄ (dibasic potassium phosphate).

Bicarbonate (NaHCO₃)

• The use of NaHCO₃ in the treatment of DKA in children is usually contraindicated.  Its use can worsen CNS acidosis and contribute to the development of cerebral edema. 
• However, if the patient is suffering from shock or cardiac insufficiency and the pH is less than 7.00, NaHCO₃ may be useful to improve cardiac performance.  The usual dose is 1 mEq/kg NaHCO₃^- over 60 minutes.  Remember, 1 ampule of 8.4% NaHCO₃ is 44 mEq of Na ⁺, therefore if an ampule of NaHCO₃ is added to each liter of IV fluid, you need to use 0.45% NaCl to avoid a hyperosmolar solution (this makes a solution of 124 mEq/L).
• If you give NaHCO₃ in the IV solution, remember to take it out once critical acidosis and shock have been corrected.
• DO NOT give NaHCO₃ without talking to the PICU attending first.
• DO NOT give NaHCO₃ as a rapid bolus

Monitoring

1. Monitoring of BP, pulses, respiratory rate and HR and rhythm per patient classification or as ordered by a physician.
2. Accurate intake and output with urine ketones as ordered.  Record all laboratory results and clinical responses on PICU nursing flow sheet or diabetic flow sheet (C5-3).
3. Initial CBC, Chem-7 (lytes, BUN, Creatinine), glucose, pH (venous OK).  Placement of a large bore IV line to obtain frequent blood samples should be considered.
4. Blood glucose (one touch) every hour if on insulin infusion or as ordered by physician.
5. Chem-9 (lytes, BUN, Creatinine) at 2-4 hour intervals depending on severity of DKA.
6. Assess and document state of consciousness and neurological status (Glasgow Coma Scale) every 1-2 hours.  Remember that signs of cerebral edema occur once therapy has begun and may not be present initially.  Notify physician immediately of any change in neurological status.
7. Venous blood gases (for pH and HCO₃) should be monitored every 2 to 4 hours in severe DKA (pH < 7.25, HCO₃ < 15).
8. If vomiting is present or bowel sounds are absent, patient should be NPO.  If persistent vomiting and/or obtunded, patient should be NPO with an NG tube.

Cerebral Edema

1. Cerebral edema is the most dreaded complication of DKA.  It can result in herniation and death if not recognized and treated immediately.
2. Cerebral edema usually occurs within the first 8 to 12 hours of treatment.
3. Suspect cerebral edema if
• Complaint of headache
• Fluctuating mental status, agitation or development of comatose state.
• Sluggish or unequal pupils
• Papilledema
• Hypertension which was not present at admission (be especially nervous is you see hypertension and bradycardia).
• Loss of control of bladder/bowel function.

Therapy for cerebral edema

• Mannitol 0.5 to 1 g/kg IV bolus (give in large bore IV, can cause severe necrosis and sloughing of tissue).
• Consider CT scan, if patient is obtunded or comatose.
• If patient comatose, consider urgent intubation for hyperventilation.  Use elevated ICP precautions.  Manually bag the patient for hyperventilation while intubation equipment and medications are being gathered.
• Consider changing the IV fluid to isotonic solution and run at maintenance rate.
• Neurology Consult.