Disorders of Calcium: Physiology
Form mg/dL Percentage of total Total 10 100 Ionized 5 50 Protein-bound 4 40 Complexed 1 10 Ca2+ plays a significant role in cellular metabolic functions; such as muscle and…
Form mg/dL Percentage of total Total 10 100 Ionized 5 50 Protein-bound 4 40 Complexed 1 10 Ca2+ plays a significant role in cellular metabolic functions; such as muscle and…
Cause Mechanism Decreased intake Protein-calorie malnutrition Poor Mg2+ intake Starvation Poor Mg2+ intake Prolonged i.v. therapy without Mg2+ Poor Mg2+ intake Chronic alcoholism Possible mechanisms include: (1) poor dietary intake;…
Fig. 20.1 Phosphate homeostasis in an adult subject. (The filtered load of phosphate equals the free plasma concentration of 3.5 mg/dL multiplied by the GFR of 180 L per day, i.e., 180 L × 35 mg/L = 6,300 mg/day.)…
Type pCO2 (mmHg) Expected renal response (compensation) Expected serum [HCO3 −] pH (calculated from Henderson equation) Normal 40 – 24 7.40 Acute 20a For each mmHg decrease in pCO2, HCO3…
Cause Mechanism Pseudohypocalcemia MRI with contrast agents (gadodiamide and gadoversetamide) interferes with colorimetric determination of Ca2+ Low serum albumin levels (for each gram decrease in serum albumin from 4.0 g/dL, serum…
Type pCO2 (mmHg) Expected secondary response (compensation) Expected serum [HCO3 −] pH (calculated from Henderson equation) Normal 40 – 24 7.40 Acute 70a For each mmHg increase in pCO2, HCO3…
Subjects Amount (mEq) of filtered HCO3 − Amount (mEq) reabsorbed in the proximal tubule Amount (mEq) delivered to distal segments Amount (mEq) of HCO3 − excreted Urine pH Normal 4,320…
Cause Mechanism Systemic diseases Acute kidney injury ↓ excretion Chronic kidney disease stages 4–5 ↓ excretion Familial hypocalciuric hypercalcemia ↓ excretion Adrenal insufficiency ↑renal absorption Acromegaly ↓ excretion Mg 2+…
Cause Mechanism Addition of phosphate to ECF compartment Endogenous Hemolysis Release from hemolyzed red blood cells Rhabdomyolysis Release from muscle cells Tumor lysis syndrome Release from tumor cells due…
GI gastrointestinal tract, PTH parathyroid hormone Some Specific Causes of Hypercalcemia Primary Hyperparathyroidism Primary hyperparathyroidism (PHPT) is the most underlying and leading cause of hypercalcemia in the general population More…