BMP Flashcards
What are the main components of a BMP?
- Sodium (Na)
- Potassium (K)
- Chloride (Cl)
- Bicarbonate (HCO3)
- Creatinine (Cr)
- Blood Urea Nitrogen (BUN)
- Calcium (Ca)
What main information does a BMP provide?
- Fluid and electrolyte status
- Renal function
What is the normal value of Potassium (K)?
3.5-5.0 mEq/L
What is the main role of potassium?
-Body’s major intracellular cation
-Main determinate of resting cell membrane potential
*important for cardiac b/c action potentials
What is hypokalemia?
-Low potassium
<3.5
What are signs and symptoms of hypokalemia?
-Typically vague –> generalized weakness, malaise, paresthesias (pins and needles sensation)
What is the most common cause of hypokalemia?
Diuretic induced renal or diarrheal induced gastrointestinal losses of potassium
(AKA fluid loss or being on a diuretic)
What is the treatment for hypokalemia?
\<3.2 = supplement with oral potassium \<3.0 = supplement with IV potassium (this is very painful)
What is hyperkalemia?
High potassium
>5.5
What are the signs and symptoms of hyperkalemia?
- Typically vague –> generalized weakness, muscle fatigue, nausea
- More significant with moderate to severe hyperkalemia (>6.0) –> palpitations, chest pain
What are the causes of hyperkalemia?
- Decreased excretion (renal failure, addison’s disease)
- Increased production (aka tissue injury) (burns, rhabdomyolysis, crush injury)
- Transcellular shift (metabolic acidosis, hyperglycemia)
- Fictitious (pseudohyperkalemia)
- Drugs (digoxin)
- Rarely ever from increased K intake
What patient population would be at an increased risk for hyperkalemia?
Patients on dialysis (specifically patients who skip dialysis can have severe hyperkalemia)
What is the normal range of Sodium (Na) and what is the role of sodium?
- 135-145 mg/L
- Predominant extracellular cation
What is the role of ASH and aldosterone?
- ADH (pituitary) → H2O retention
- Aldosterone (kidneys) → sodium reabsorption
What is hyponatremia?
Sodium <135
-Disorders of ECF volume (volume status, serum osmolality)
What are signs and symptoms of hyponatremia?
Headache, fatigue, difficulty concentrating, cramping, confusion, lethargy, agitation, N/V, seizures, dehydration, tachycardia, dry mucous membranes, sunken fontanelles
What are the causes of hyponatremia?
- Hypertonic (hyperglycemic) increased solute
- Isotonic (hyperlipidemia, hyperproteinemia)
- Hypotonic (diuretic use, GI loss, renal failure, CHF, nephrotic syndrome, cirrhosis)
What is hypernatremia?
High sodium
>145
What are the signs and symptoms of hypernatremia?
Lethargy, irritability, restlessness, spasticity, seizure, tachycardia, orthostasis, dry mucous membranes, diminished skin turgor, oliguria
What are some causes of hypernatremia?
- Hypervolemia (glucocorticoid excess, cushing syndrome)
- Hypovolemia (volume loss, GI, renal, diabetes indipidus)
What is the role of chloride (Cl) and what is the normal range?
Anion involved in acid-base regulation and fluid balance
95-100
What is hypochloremia and what are the signs and symptoms?
Cl <95
- Rarely occurs in absence of other metabolic abnormalities
- Vomiting, diarrhea, dehydration (tachycardia, poor skin turgor, dry mucous membranes, sunken fontanelles)
What are the causes of hypochloremia?
- Primarily volume contraction
- Vomiting, diarrhea, NG tube, diuretic overuse, CF
What is hyperchloremia and what are signs and symptoms?
Cl >105
-Often asymptomatic, may have signs of hypernatremia
What are some causes of hyperchloremia?
- Advanced dehydration
- Kidney disease
- Carbonic anhydrase inhibitors
- Over agressive IVF’s
What is bicarbonate (HCO3) and what are the normal values?
22-28 (24 is good)
- Anion involved in acid-base regulation and fluid balance
- Important part of buffering system
- BASIC
- Regulated by renal tubules of kidneys and lungs
What is hypobicarbonemia and what are signs and symptoms?
Bicarb <22
*Sx not caused by hypobicarbonemia, but but the acid-base imbalance
-N/V, abdominal pain, weakness, dizziness, AMS, tachycardia, orthostasis, poor skin turgor, Kussmaul respirations, fruity odor
What are the causes of hypobicarbonemia?
Metabolic acidosis, chronic diarrhea, kidney disease, adrenal insufficiency
What is hyperbicarbonemia and what are signs and symptoms?
Bicarb >28
-Very rare, seen when the body has lost volume so the bicarb appears high
-N/V, diarrhea, SOB, dehydration
What are some causes of hyperbicarbonemia?
-Metabolic alkalosis
- Chronic respiratory acidosis
- Conn’s syndrome
- Cushing’s syndrome
What is creatinine and what are the normal values?
Male = 0.5-1.5
Female = 0.6-1.2
- Byproduct of creatine phosphate
- Primarily used to determine renal function
What is hypocreatinemia, signs and symptoms and causes?
Creatinine <0.5 (not really a problem)
- Possibly signs of starvation, muscle atrophy
- Causes: decreased muscle mass, inadequate protein intake
What is hypercreatinemia, signs and symptoms and causes?
Creatinine >1.2 (females) >1.5 (males)
- Fatigue, vomiting, diarrhea, dry mucous membranes, shortness of breath, edema, confusion
- Beginning of kidney failure!!
- Causes = kidney disease (look at BUN:Cr ratio)
What is BUN and what is the normal range?
8-20 mg/dL
Blood Urea Nitrogen
- Liver makes urea, kidneys excrete it
- Primarily used to determine renal function
What are signs and symptoms of decreased BUN and causes?
BUN <8
- Possibly signs of starvation, muscle atrophy
- Causes: decreased muscle mass, inadequate protein intake, liver disease, aggressive IVF
What are signs and symptoms of increased BUN and causes?
BUN >20
- Vomiting, diarrhea, melen/hemtochezia, dehydration, uremic “frost”
- Causes: kidney disease, hypovolemia, GI hemorrhage, CHF
*Increased BUN means liver is working but kidneys are NOT (because liver makes urea and kidneys excrete it)
What are the normal ranges of the BUN:Cr ratio?
10:1-20:1
How do you calculate BUN:Cr ratio?
(BUN #) / (Cr #) :1
What is a BUN:Cr ratio >20:1 indicative of?
PRERENAL - before the kidneys
→ renal artery stenosis
→ dehydration
→ Blood loss (not enough blood to the kidneys, usually a ratio of 30:1 or greater)
-Azotemia (buildup of waste products in the blood), hypoperfusion/dehydration, GI bleed, CHF
What is BUN:Cr ratio 10-20:1 indicative of?
Postrenal or normal
→ Stone (anything blocking)
→ BPH (do a bladder scan)
What is a BUN:Cr ratio <10:1 indicative of?
INTRINSIC (in the kidney’s)
→ kidney failure
→ Medications (NSAIDs)
→ Renal tubular acidosis
→ Nephritis
BUN = 42
Cr = 1.5
What is the BUN:Cr ratio and what might this indicate?
42/1.5 = 28
28:1 (increased BUN:Cr)
GI BLEED
What is the function and normal range of calcium?
- 5-10.5 mEq/dL
- Important cation → comprises main mineral component of bone
- Parathyroid hormone → key controller of serum calcium concentration
- Vitamin D → stimulates calcium absorption in gut
How do albumin levels affect calcium levels?
- 50% of blood calcium is bound by protein (mostly albumin)
- Decrease in albumin → decrease in total serum calcium
(decrease of 0.8mg serum Ca for every 1g decrease in albumin)
-Does NOT affect the ionized (free form) calcium concentration
What is the value and signs/symptoms of hypocalcemia?
Ca <9
-Neuromuscular irritability (hallmark of hypocalcemia)
-Acute symptoms seen <7
-Severe hypocalcemia = prolonged QT interval leading to Torsades
-tetany, paresthesias, muscle cramps, spasms, seizures, hyperreflexia, Chovestek’s sign and Trousseau’s sign
What is Chvostek’s sign?
Twitching of the facial muscles in response to tapping over the area of the facial nerve
What is Trousseau’s sign?
Hand muscle spasm caused by inflating the BP cuff to level over systolic pressure for 3 minutes
What is the value and signs/symptoms of hypercalcemia?
Ca > 10.5
-Symptoms appear with Ca >12
-Stones, bones, groans and moans
→ Bones = Ca pulled from bones (aches, pains, fractures)
→ Moans = GI complaints (constipation, nausea, decreased appetite)
→ Stones = kidney, flank pain, frequency (extra Ca can form kidney stones)
→ Groans = psych (confusion, dementia, memory loss, depression)
What are some causes of hypercalcemia?
-Hyperparathyroidism
-Malignancy
- Medications
- Adrenal insufficiency