Diabetic Ketoacidosis
Pt with h/o DM type 1 presents with sub-acute onset of polyuria/polydipsia with concomitant weight loss, fatigue, dyspnea, N/V, abdominal pain, polyphagia. Reports recent pneumonia, UTI, cocaine/alcohol abuse. Medications include second generation antipsychotics. Has not been taking insulin as instructed due to pump failure, financial issues, confusion about insulin regimen. Febrile and stuporous with dry mucous membranes on exam. Initial labs show serum bicarbonate < 18 mEq/L, glucose > 250 mg/dL, anion gap (AG) > 16 mEq/L, serum osmolality > 320, pH on ABG < 7.3.
Labs
Obtain CBC, CMP, ABG, U/A
Obtain serum beta-hydroxybutyrate, amylase, lipase, lactic acid, creatinine kinase
Obtain HbA1c if not performed within previous 3 months
Timed
Obtain BMP, phosphorus, magnesium q4 hours until AG < 12
Obtain fingerstick glucose q1 hour x 4
Report intake and output q4 hours
IV fluid
Initial progression
Normal saline (0.9%) at 1 L/h x 1h, then 500 mL/h x 2h then
0.45% saline at 500 mL/h x 2h then
0.45% saline at 200 mL/h maintenance
When WBG < 250 mg/dL, start D5 0.45% saline at 200 mL/hr
If initial potassium
4 to 5.2: Infuse KCl at 10 mEq/h IV x 2h
3.3 to 4: Infuse KCl at 10 mEq/hr IV x 3h
3.2 or lower: Replete as appropriate and start KCl at 10 mEq/hr IV x 3h
Insulin
Start insulin infusion at 0.1 u/kg/h; max 10 u/h
When WBG < 250 mg/dL and decreased 100 mg/dL from starting value, decrease infusion rate by half and recheck WBG in 30 min
When WBG < 200 mg/dL and decreased 60 mg/dL in previous 2 hours, decrease insulin rate by half
When WBG <100mg/dL, decrease insulin rate by half and change to D10 0.45% saline at current rate
Administer long-acting insulin SQ when AG < 12 and serum CO2 > 14
Continue insulin infusion for 30 minutes after starting long acting insulin
Additional evaluation and treatment
Obtain EKG
Zofran 4 mg IV q8h PRN for nausea
Monitor for s/sx of cerebral edema
Pt's family advised that fatality rate is up to 5%
Educate pt and family about insulin adjustment during illness, blood glucose monitoring, and importance of medication compliance
Notes
Febrile illness precedes 40% of DKA cases
AG = anion gap = Na - (Cl + CO2)
Serum osmolality = 2(Na + K) + (glucose/18) + (blood urea nitrogen/2.8)
Bicarbonate therapy is has not be shown to improve outcomes
Rule out
10-15% of DKA patients have concomitant pancreatitis; rule in/out with serum amylase, lipase
Other high anion-gap metabolic acidosis, e.g. lactic acidosis, uremia, rhabdomyolysis, toxic alcohol ingestion (alcohol, ethylene glycol, methanol)
HHS
diagnosis = serum glucose >600, osmolarity >300, absent/minimal ketonse, arterial pH>7.3, serum bicarb>20
-high flow NS; add dextrose 5% when WBG <200
-serum potassium <= 5.2; add IV potassium
-serum potassium >=3.3; start initial continuous insulin infusion
-consider bicarbonate if pH < 6.9
-consider phosphate for serum phosphate <1.0 mg/dL, cardiac dysfunction, respiratory depression
-frequent monitoring of serum Ca
-tolerates PO intake, WBG<200mg/dL, anion gap<12 and serum HCO3 >15; d/c start SQ basal bolus insulin and d/c IV insulin in 1-2 hours
(true for DKA as well)