Respiratory alkalosis results from increased alveolar respiration ( hyperventilation) leading to decreased plasma carbon dioxide concentration. This leads to decreased hydrogen ion and bicarbonate concentrations.
Additional recommended knowledge
There are two types of respiratory alkalosis: chronic and acute.
In acute respiratory alkalosis, increased levels of carbon dioxide are "blown off" by the lungs, which are hyperventilating. During acute respiratory alkalosis, the person may lose consciousness where the rate of ventilation will resume to normal.
In chronic respiratory alkalosis, for every 10 mM drop in pCO 2 in blood, there is a corresponding 5 mM of bicarbonate ion drop. The drop of 5 mM of bicarbonate ion is a compensation effect which reduces the alkalosis effect of the drop in pCO 2 in blood. This is termed metabolic compensation.
Causes of the alveolar hyperventilation seen in respiratory alkalosis include:
anxiety, hysteria and stress
moving into high altitude areas, when the low atmospheric pressure of oxygen stimulates increased ventilation
pyrexia in fever, which stimulates the respiratory centre in the brainstem
drugs, including doxapram and large doses of aspirin, which also stimulate the respiratory centre
CNS causes, including stroke, subarachnoid haemorrhage, meningitis
a hypoxic drive in lung disease, such as pneumonia
caffeine overdose and coffee abuse
In addition, a respiratory alkalosis is often produced accidentally by doctors (
iatrogenically) during mechanical ventilation of patients.
Symptoms of respiratory alkalosis are related to the decreased blood carbon dioxide levels, and include peripheral
paraesthesiae. In addition, the alkalosis may disrupt calcium ion balance, and cause the symptoms of hypocalcaemia (such as tetany) with no fall in total serum calcium levels.
Metabolic pathology / Inborn error of metabolism ( E70-90, 270-279) Amino acid Aromatic ( Phenylketonuria, Alkaptonuria, Ochronosis, Tyrosinemia, Albinism, Histidinemia) - ( Organic acidemias Maple syrup urine disease, Propionic acidemia, Methylmalonic acidemia, Isovaleric acidemia, 3-Methylcrotonyl-CoA carboxylase deficiency) - Transport ( Cystinuria, Cystinosis, Hartnup disease, Fanconi syndrome, Oculocerebrorenal syndrome) - Sulfur ( Homocystinuria, Cystathioninuria) - ( Urea cycle disorder N-Acetylglutamate synthase deficiency, Carbamoyl phosphate synthetase I deficiency, Ornithine transcarbamylase deficiency, Citrullinemia, Argininosuccinic aciduria, Hyperammonemia) - Glutaric acidemia type 1 - Hyperprolinemia - Sarcosinemia Carbohydrate Lactose intolerance - Glycogen storage disease ( type I, type II, type III, type IV, type V, type VI, type VII) - fructose metabolism (Fructose intolerance, Fructose bisphosphatase deficiency, Essential fructosuria) - galactose metabolism ( Galactosemia, Galactose-1-phosphate uridylyltransferase galactosemia, Galactokinase deficiency) - other intestinal carbohydrate absorption ( Glucose-galactose malabsorption, Sucrose intolerance) - pyruvate metabolism and gluconeogenesis ( PCD, PDHA) -
Pentosuria - Renal glycosuria Lipid storage Sphingolipidoses/ Gangliosidoses: GM2 gangliosidoses ( Sandhoff disease, Tay-Sachs disease) - GM1 gangliosidoses - Mucolipidosis type IV - Gaucher's disease - Niemann-Pick disease - Farber disease - Fabry's disease - Metachromatic leukodystrophy - Krabbe disease
Neuronal ceroid lipofuscinosis ( Batten disease) - Cerebrotendineous xanthomatosis - Cholesteryl ester storage disease ( Wolman disease) Fatty acid metabolism Lipoprotein/lipidemias: Hyperlipidemia - Hypercholesterolemia - Familial hypercholesterolemia - Xanthoma - Combined hyperlipidemia - Lecithin cholesterol acyltransferase deficiency - Tangier disease - Abetalipoproteinemia
Fatty acid: Adrenoleukodystrophy - Acyl-coA dehydrogenase (Short-chain, Medium-chain, Long-chain 3-hydroxy, Very long-chain) - ( Carnitine Primary, I, II) Mineral Cu Wilson's disease/ Menkes disease - Fe Haemochromatosis - Zn Acrodermatitis enteropathica - PO Hypophosphatemia/ 4 3− Hypophosphatasia - Mg 2+ Hypermagnesemia/ Hypomagnesemia - Ca 2+ Hypercalcaemia/ Hypocalcaemia/ Disorders of calcium metabolism Fluid, electrolyte and acid-base balance Electrolyte disturbance - Na + Hypernatremia/ Hyponatremia - Acidosis ( Metabolic, Respiratory, Lactic) - Alkalosis ( Metabolic, Respiratory) - Mixed disorder of acid-base balance - H 2O Dehydration/ Hypervolemia - K + Hypokalemia/ Hyperkalemia - Cl Hyperchloremia/Hypochloremia − Purine and pyrimidine Hyperuricemia - Lesch-Nyhan syndrome - Xanthinuria Porphyrin Acute intermittent, Gunther's, Cutanea tarda, Erythropoietic, Hepatoerythropoietic, Hereditary copro-, Variegate Bilirubin Unconjugated ( Lucey-Driscoll syndrome, Gilbert's syndrome, Crigler-Najjar syndrome) - Conjugated (Dubin-Johnson syndrome, Rotor syndrome) Glycosaminoglycan Mucopolysaccharidosis - 1:Hurler/ Hunter - 3:Sanfilippo - 4:Morquio - 6:Maroteaux-Lamy - 7:Sly Glycoprotein Mucolipidosis - I-cell disease - Pseudo-Hurler polydystrophy - Aspartylglucosaminuria - Fucosidosis - Alpha-mannosidosis - Sialidosis Other Alpha 1-antitrypsin deficiency - Cystic fibrosis - Amyloidosis ( Familial Mediterranean fever) - Acatalasia