Endocrine and Electrolytes Flashcards
Hyperglycemia is defined as (on this website):
Fasting Blood Glucose (for 8 hrs) > ________ mg/dL
Postprandial Blood Glucose > _______ mg/dL
90 – 130
180
What are the most common precipitating factors to cause DKA?
infections, disruption of insulin therapy, or as the presentation of new onset diabetes
- DKA more common in younger pts
Which has higher mortality, DKA or hyperglycemic hyperosmolar state (HHS)?
HHS
- More common in older pts
Review these causes of hyperglycemia 2/2 increase in insulin counter-regulatory hormones.
Cocaine use Infection / sepsis Myocardial ischemia / infarction Surgery Trauma
Patients with mild hyperglycemia may in fact be asymptomatic. Once the blood glucose level rises above ~ ____ mg/dL (renal threshold), patients will start to develop an osmotic diuresis.
180 mg/dL
List the early sx of hyperglycemia
Polyuria Polydipsia Polyphagia Weight loss Tachycardia Dizziness Lightheadedness Weakness
As the degree of hyperglycemia progresses leading to marked volume depletion, electrolyte disturbance, acidosis, ketosis, etc. additional sx may be seen including:
Abdominal pain Kaussmaul respirations Hypotension Fruity breath (if DKA, from ketones) Marked tachycardia Neurologic sx (seizures, focal weakness, lethargy, coma, death)
Are neurologic sx of severe hyperglycemia (seizures, focal weakness, lethargy, coma) more common in DKA or HHS?
HHS
What labs/tests should be ordered in hyperglycemia?
- Why would you get an EKG?
- bedside glucose
- UA (look for ketones)
- BMP (lytes and AG)
- CBC (infxn)
- ABG
- Phos/Mg2+ (may be off if dehydrated)
- *EKG (extracellular K+ shifts)
- Other (based on presentation)
List how the following values differ b/w DKA and HHS:
Plasma glucose (> what value?) Arterial pH (< or > 7.30) Serum bicarbonate (< or > 18?) Urine ketones (yes or sometimes?) Serum ketones (yes or sometimes?) Serum osmolality (elevated or severely elevated?) Anion gap (yes or no) Mental Status?
DKA HHS - Plasma glucose (mg/dL) >250 >600 - Arterial pH <7.30 >7.30 - Serum bicarbonate(mEq/L) <18 >18 - Urine ketones +++ – or faintly + - Serum ketones +++ – or faintly + - Serum osmolality (mOsm/kg) ↑ ↑↑↑ - Anion gap >>>12 Normal (12-16) - Mental Status Variable -- from alert to coma (DKA) Stupor/coma (HHS)
Treatment for DKA and HHS is centered around correcting these 4 measures:
- intravascular volume depletion
- management of electrolyte abnormalities
- insulin replacement therapy
- identification of and treatment of any underlying precipitants.
*Discuss the fluid replacement strategy in DKA/HHS (3 steps)
- Start with isotonic saline (0.9%) at 15-20 mL/kg/hour for the first FEW HOURS (in the average adult this will be approximately 1 liter/hr)
- Switch to one-half isotonic saline (0.45%) when the serum SODIUM normalizes
- Add dextrose to the intravenous fluids when serum GLUCOSE reaches 250 mg/dL
In hyperglycemia, what do you need to do before giving insulin?
Correct electrolyte abnormalities
Once electrolytes are corrected, how do you start correcting insulin/glucose?
What should you do if the blood glucose does not fall by 50-70 mg/dL in the first hour?
Start with an infusion of regular insulin at 0.1 U/kg/hour (can give loading dose if you want)
Double the dose of insulin
In correcting hypoglycemia, if the initial potassium is < 3.3 mEq/L, should you correct the potassium or insulin first?
Potassium (delay insulin)
Why is bicarbonate replacement in hyperglycemia tx controversial?
Correction may cause a paradoxical fall in cerebral pH and neurologic deterioration
Certain situations may warrant the use of bicarbonate, such as:
- Severe acidosis with pH < 6.90
- Severe life-threatening hyperkalemia
- Seizures
- Cardiac or persistently hypotensive patient
What requires frequent monitoring in the DKA/HHS pt?
- Blood glucose every hour until stable, then every 2–4 hours
- BMP and blood pH every 2–4 hours during therapy until patient stabilizes
- One very serious complication of DKA/HHS is cerebral edema, with a high degree of morbidity and mortality.
- What types of pts is it seen in?
- When does it occur?
- What sx is it preceded by ?
- It is mainly seen in children and young adults
- Occurring 4-12 hours into tx
- Often preceded by headache, lethargy, then neurologic deterioration (seizures, coma) with bradycardia and respiratory arrest.
Although not completely understood development of cerebral edema is correlated with ___________________ and ___________________.
bicarbonate administration and massive fluid resuscitation
Another name for glucophage?
Metformin
Which hyperglycemia pts always require hospital admission?
DKA
HHS
- Less severe can often be d/c’d w/close f/u
*What range should potassium be kept within during severe hyperglycemia tx?
*4-5
*When treating hyperglycemia, why do you need to make sure to start dextrose containing fluids once the glucose level is lowered to 250 mg/dL
Avoid hypoglycemia
What is the most common condition leading to hyperkalemia?
Missed dialysis in a patient with ESRD
Think of some conditions a/w hyperkalemia.
- Acute renal failure
- Extensive burns
- Trauma
- Severe rhabdomyolysis
- Severe acidosis.
- Acute digoxin toxicity
- Adrenal insufficiency