DKA Flashcards
What % of patients with T1DM will experience DKA?
5%
What is the pathophysiology of DKA?
Catabolic condition that results from severe insulin deficiency, often associated with stress and activation of counterregulatory hormones (eg catecholamines, glucagon)
What are precipitating factors of DKA?
- Inadvertent or deliberate interruption of insulin therapy
- Sepsis
- Trauma
- MI
- Pregnancy
What type of patient education should you provide for T1DM regarding prevention of DKA?
- Reinforced at every opportunity, with special emphasis on:
- Self-management skills during sick days
- The body’s need for more, rather than less, insulin during illness
- Testing of blood or urine for ketones
- Procedures for obtaining timely preventive medical advice
What are sx of DKA?
- Polyuria
- Polydipsia
- Weight loss
- N/V
- Vaguely localized abdominal pain
What do you find on PE in a patient with DKA?
- Tachycardia
- decrease in cap filling
- rapid, deep, and labored breathing (Kussmaul respiration)
- fruity breath odor
- Prominent GI sx and abdominal tenderness
- Dehydration is invariable and resp. distress, shock, and coma
What is the lab workup for someone with DKA and what do you expect to see reflected in those labs?
- Labs: anion gap metabolic acidosis and positive serum B-hydroxybutyrate or ketones
- Plasma glucose level elevated but may be moderate (<300mg/dL) in 10-15%
- Urine ketones
- Hyponatremia, hyperkalemia, azotemia, hyper osmolality
- Serum amylase, transaminase, and/or triglycerides may be elevated
- Focused search for precipitating infection if clinically indicated
- ECG for electrolyte abnormalities and unsuspected MI
What are the three main focuses of DKA management?
- Fluid replacement
- Adequate insulin administration
- Potassium repletion
What are the two main interventions/goals of fluid resuscitation?
Restoration of circulating volume
Replenish total body water deficits
Which type of fluid should be used to restore circulating volume?
At what rate is the fluid restoring circulating volume infused?
Rapidly (if cardiac function is normal) and should be followed by additional fluids at a rate of 0.5-1.0L/hr until vital signs have stabilized and UO has been established
What type of fluid should be used to replenish total body water deficits?
- 45% saline if the corrected serum sodium level is normal or elevatd
- 9%NaCl if corrected serum sodium level is low
At what rate is the fluid to replenish total body water deficits infused?
Infusion at 150-500 mL/hr: rate depends on degree of dehydration, cardiac and renal status
What are end targets for replenishing total body water deficits?
- Not exceeding a change in osmolality >3 mOsm/kg/hr
- Success is judged by improvement of BP, UO, and clinical examination
How long does it typically take for fluid replacement to occur in the typical DKA patient?
12-24 hours
Which type of insulin is used in DKA?
Regular Insulin
How is insulin for DKA dosed?
IV bolus 10-15 U administered immediately followed by a continuous infusion of regular insulin at an initial rate of 5-10 U/hr
What is the target rate of decrease in blood sugar levels in DKA?
50-75mg/dL/hr
If dropping quicker than the above answer, what do you need to be concerned about?
If corrected at rates >100mg/dL, can increase risk of osmotic encephalopathy
How long do you continue maintenance infusion rates in DKA?
Maintenance insulin infusion rates of 1-2 U/hr can be continued until the patient is clinically improved, the serum bicarb levels rise >15meq/L, and the anion gap has closed
How do you manage insulin and fluid therapy once glucose reaches 250 in DKA?
Dextrose (5%) in 0.45% saline should be infused and the insulin infusion rate should be decreased to 0.05U/kg/hr to prevent dangerous hypoglycemia
Why are we concerned about potassium levels in DKA and its management?
- Insulin admin results in rapid shift of potassium into the intracellular compartment
- Goal is to maintain plasma potassium level in the normal range to prevent the potentially fatal cardiac effects of hypokalemia
Discuss management of potassium levels in DKA
K should be added routinely to the IV fluids (starting with 2nd or 3rd L of fluid replacement) at a rate of 10-20 meq/hr except in patients with hyperkalemia, renal failure, or oliguria
How often do you monitor glucose levels in DKA? How often do you monitor other labs?
- BG: hourly
- Serum electrolytes: 1-2 hours
- Arterial blood gas: as often as necessary for a severely acidotic or hypoxic patient
Why is it pertinent to monitor sodium levels in the treatment of DKA?
Serum sodium tends to rise as hyperglycemia is corrected and failure to observe this trend suggests that the patient is being overhydrated with free water
How often do you monitor ketone levels in DKA?
Not necessary
ketonemia may persist after clinical recovery and because the most commonly used assays measure all ketones and not just B-hydroxybutyrate
When is bicarb therapy indicated in DKA?
- Not routinely necessary and may be deleterious in certain situations
- May be considered for DKA patients who develop
- Shock or coma
- Severe acidosis (pH<6.9)
- Severe depletion of buffering reserve (plasma bicarb <5meq/L)
- Acidosis-induced cardiac or resp. dysfunction
- Severe hyperkalemia
Name complications of DKA and their clinical presentations
- Lactic acidosis: results from prolonged dehydration, shock, infection, and tissue hypoxia
- Suspected with refractory metabolic acidosis and a persistent anion gap despite therapy for DKA
- Management: adequate volume replacement, co troll of sepsis, judicious use of bicarb constitutes the approach to management
- Arterial thrombosis: manifests as stroke, MI, or ischemic limb
- Cerebral edema: observed more frequently in children
- Sx: increased intracranial pressure (HA, altered mental status, papilledema) or sudden deterioration in mental status after initial improvement
- Risk factors: over hydration with free water and excessively rapid correction
- CT scan can establish dx
- Tx: recognition and IV mannitol
- Rebound ketoacidosis from premature cessation of IV insulin infusion or inadequate doses of SC insulin after infusion d/c.
