Hypocalcemia
Classification according to ICD-10 | |
---|---|
E83.5 | Disorders of calcium metabolism |
e58 | Alimentary calcium deficiency |
P71.0 | Newborn cow milk hypocalcemia |
P71.1 | Other neonatal hypocalcaemia |
ICD-10 online (WHO version 2019) |
Hypocalcemia (also hypocalcemia, hypocalcemia, or hypocalcemia ) is abnormally low levels of calcium in the blood. In humans, one speaks of hypocalcemia, when the calcium level in the blood serum of below 2.2 mmol / l (9 mg / dl) or the content of calcium - ion below 1.1 mmol / l (4.5 mg / dl) is located. It causes a disruption of the balance between different electrolytes and can lead to an over-excitability of the nervous system , which manifests itself in cramps in the skeletal muscles . In some cases, one is spasm of smooth muscle triggered. In general, the parathyroid hormone counteracts hypocalcemia in the short term, calcitriol serves to adjust the calcium level to normal values over the long term.
Etiology and pathogenesis
Possible causes of hypocalcemia are:
- Underactive parathyroid gland and thus a lack of parathyroid hormone ( hypoparathyroidism )
- increased calcium requirement during pregnancy / pregnancy and lactation ( milk fever )
- Calcium deficiency or excess phosphorus in the diet
- increased calcium loss via the kidneys in renal insufficiency
- decreased effect of the parathyroid hormone , the main function of which is to increase the calcium concentration in the blood plasma (see pseudohypoparathyroidism )
- Hypomagnesaemia (magnesium deficiency)
- Poisoning with ethylene glycol
- Pancreatitis (inflammation of the pancreas)
- Lack of albumin (a blood protein) ( hypoalbuminemia )
- Overactive C cells of the thyroid ( Hyperkalzitonismus )
- Bulimia (vomiting)
- Hyperventilation (actually this is a pseudo-hypocalcemia: the more breathing increases the pH value of the blood, the calcium binding to albumin is increased and there is less free calcium available in the blood)
- Celiac disease (poor absorption)
- osteoblastic metastases (e.g. prostate or breast cancer )
- high, iatrogenic citrate levels during blood transfusions and apheresis
Symptoms
The main symptom of hypocalcemia is hypocalcemic tetany , a seizure while conscious as a result of hyperreactivity of the muscle spindle , often associated with paresthesia , paws and glottis . Another sign is the Chvostek sign , in which tapping the facial nerve in front of the temporomandibular joint causes the corners of the mouth to twitch. The Trousseau sign can also appear. A few minutes after applying a blood pressure cuff to the arm, paws are inflated using the systolic blood pressure.
The ECG shows a QT prolongation.
Differential diagnosis
A possible differential diagnosis is hyperventilation tetany , in which total calcium is normal, but ionized calcium is reduced as a result of respiratory alkalosis .
therapy
Therapy must turn off the triggering reason. If there is an acute need for treatment, calcium is administered intravenously (about 5–10 mg / kg over several minutes); for long-term treatment, calcium and vitamin D are administered orally.
See also
literature
- G. Herold and others: Internal medicine. Self-published, Cologne 2005, OCLC 314915893 .
- Deetjen, Speckmann, Hescheler: Repetitorium Physiologie. 1st edition. Urban & Fischer, 2005, ISBN 3-437-41314-7 .
- RF Schmidt, F. Lang, G. Thews: Physiology of humans. 29th edition. Springer, Berlin et al. 2005, ISBN 3-540-21882-3 .
Individual evidence
- ^ ME Meininger, JS Kendler: Images in clinical medicine. Trousseau's sign . In: The New England Journal of Medicine . tape 343 , no. December 25 , 2000, pp. 1855 , PMID 11117978 .
- ↑ Reinhard Larsen: Anesthesia and intensive medicine in cardiac, thoracic and vascular surgery. (1st edition 1986) 5th edition. Springer, Berlin / Heidelberg / New York et al. 1999, ISBN 3-540-65024-5 , p. 56.