Disorders of Magnesium: Physiology
Fig. 23.1 Mg2+ homeostasis in an adult subject. (Filtered load of Mg2+ equals plasma free Mg2+ concentration of 1.1 mg/dL times GFR of 180 L/day; i.e., 180 L × 11 mg/L = 1,980 mg/day. Note that the intake of…
Disorders of Phosphate: Hypophosphatemia
Cause Mechanism Shift from extracellular to intracellular compartment Glucose Transcellular distribution Insulin Transcellular distribution Catecholamines Transcellular distribution Hyperalimentation Glucose-induced cellular uptake Respiratory alkalosis Transcellular distribution Refeeding syndrome Glucose and insulin-induced…
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…
Disorders of Magnesium: Hypomagnesemia
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;…
Disorders of Phosphate: Physiology
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.)…
Respiratory Alkalosis
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…
Disorders of Calcium: Hypocalcemia
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…
Respiratory Acidosis
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…
Hyperchloremic Metabolic Acidosis: Renal Tubular Acidosis
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…
Disorders of Magnesium: Hypermagnesemia
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+…
