Michael Laposata, Author at Renal and Urology News - Page 2

Michael Laposata

All articles by Michael Laposata

Metabolic Alkalosis: Arterial Blood pH Elevated with Increased Arterial pCO2

Differential Diagnosis Vomiting or nasogastric suction Ingestion of certain drugs, such as diuretics Numerous endocrine disorders, including Cushing syndrome and hypoparathyroidism Suggested Additional Lab Testing Serial blood gases to assess arterial pH, arterial h2co3 and arterial pco2 are important when the disease is evolving or resolving. Tests relevant to the diagnosis of Cushing syndrome and…

Metabolic Acidosis: Low Arterial pH and Low Arterial H2CO3-

Differential Diagnosis Uncontrolled diabetes Renal failure from a variety of causes Tissue hypoxia GI h2co3 loss from diarrhea Methanol intoxication Suggested Additional Lab Testing Urinary ketones might be valuable to show increased ketoacids in uncontrolled diabetes. Urinary changes that show impaired hydrogen excretion suggest renal failure. Increased lactic acid in the blood is suggestive of…

Low TSH – Hyperthyroidism

Differential Diagnosis Graves disease Toxic multinodular goiter Toxic adenoma Subacute thyroiditis Chronic thyroiditis Suggested Additional Lab Testing Graves disease: T4 is high and in some cases T3 is elevated and T4 is normal. Toxic multinodular goiter: T4 and T3 are high with suggestive radioactive iodine uptake and thyroid scans. Toxic adenoma: T4 and T3 are…

Low Serum or Plasma Sodium

Differential Diagnosis Increase in extracellular fluid volume as produced by congestive heart failure, cirrhosis and ascites, producing dilutional hyponatremia GI loss of sodium from vomiting, diarrhea, or malabsorption, especially with replacement of fluid and not electrolytes Renal sodium loss from diuretic use or chronic renal insufficiency Addison’s disease producing adrenal insufficiency Syndrome of inappropriate antidiuretic…

Low Serum or Plasma Potassium

Differential Diagnosis Treatment with drugs Loop or thiazide diuretics Mineralocorticoids such as aldosterone and corticosterone Antibiotics such as carbenicillin and ticarcillin GI losses of potassium from vomiting, diarrhea, malabsorption Hyperaldosteronism Aldosteronism may be primary or secondary, as in renal artery stenosis. Endogenous or exogenous increase in corticosteroids from Cushing syndrome or dietary or parenteral potassium…

Low Serum or Plasma Glucose – Hypoglycemia

Differential Diagnosis Reactive hypoglycemia is usually observed in diabetics but also is found in nondiabetics following ingestion of a high-carbohydrate meal. Pts w/ hypoglycemia caused by an insulin-producing tumor may have signs & symptoms associated w/ malignancy. For surreptitious insulin injection, seek a history of insulin use or access to insulin. For excess administration of…

Low Serum Cortisol

Differential Diagnosis Primary adrenal insufficiency Secondary adrenal insufficiency with underlying disorder Suggested Additional Lab Testing Primary adrenal insufficiency Exogenous ACTH does not stimulate cortisol secretion, and the plasma ACTH is elevated. Serum aldosterone is low in cases in which destruction of the adrenal gland affects both cortisol and aldosterone production. Testing for antibodies against the…

Low Serum Calcium

Differential Diagnosis Decreased exposure to sunlight, milk allergies, and adherence to a strict vegetarian diet can lead to vitamin D deficiency. Vitamin D deficiency state or abnormal metabolism of vitamin D: A deficiency can also occur from malabsorption of vitamin D. Abnormal metabolism of vitamin D, ultimately to 1,25-dihydroxy vitamin D, is found most commonly…

Low pO2 (Hypoxemia or Low O2 in Blood)

Differential Diagnosis Chronic bronchitis Emphysema Asthma Pneumoconioses Central or peripheral neuromuscular disorders Right-to-left shunts of great vessels Pulmonary embolism and pulmonary infarction Sarcoidosis Selected lung cancers Suggested Additional Lab Testing If there is a need to monitor blood gases, pCO and blood pH would be useful. In most of these circumstances, the testing is performed…

Low Hemoglobin or Hematocrit

Differential Diagnosis Iron deficiency anemia Thalassemia Anemia of chronic disease Acute blood loss Lead poisoning Anemia from folate or vitamin B12 deficiency Sickle cell anemia Hereditary spherocytosis or elliptocytosis Hemoglobinopathies other than sickle cell disease Autoimmune hemolytic anemia Hemolytic disease of the newborn Microangiopathic hemolytic anemia Glucose-6-phosphate dehydrogenase (GGPD) deficiency Pyruvate kinase deficiency Paroxysmal nocturnal…

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