Chvostek's sign
Chvostek’s sign is an abnormal spasm of the facial muscles that’s elicited by lightly tapping the patient’s facial nerve near his lower jaw. (See Eliciting Chvostek’s sign.) This sign usually suggests hypocalcemia but can occur normally in about 25% of patients. Typically, it precedes other signs of hypocalcemia and persists until the onset of tetany. It can’t be elicited during tetany because of strong muscle contractions.
Usually, eliciting Chvostek’s sign is attempted only in patients with suspected hypocalcemic disorders. However, because the parathyroid gland regulates calcium balance, Chvostek’s sign may also be tested in patients before neck surgery to obtain a baseline.
Emergency Actions
Test for Trousseau’s sign, a reliable indicator of hypocalcemia. Closely monitor the patient for signs of tetany, such as carpopedal spasms or circumoral and extremity paresthesia.
Be prepared to act rapidly if a seizure occurs. Perform an electrocardiogram to check for changes associated with hypocalcemia, which can predispose the patient to arrhythmias. Place the patient on a cardiac monitor.
History
Obtain a brief history. Find out if the patient has had the parathyroid glands surgically removed or if he has a history of hypoparathyroidism, hypomagnesemia, or malabsorption disorder. Ask him or his family if they have noticed any mental changes, such as depression or slowed responses, which can accompany chronic hypocalcemia. Question the patient about tingling around the mouth and in the fingertips and feet.
Physical assessment
During your assessment, observe the patient’s behavior. Anxiety and irritability may signal hypocalcemia. Also observe him for seizures, tetany, and facial spasms. Observe his skin for dryness or scaling, brittle nails, and dry hair. Take your patient’s vital signs. Be alert for an irregular pulse and hypotension, which suggests low calcium levels. Auscultate the patient’s lungs. Note any signs of bronchospasm, laryngospasm, and airway obstruction. Increased GI motility produces hyperactive bowel sounds.
Medical causes
Hypocalcemia
Chvostek’s sign may indicate hypocalcemia. The degree of muscle spasm elicited reflects the patient’s serum calcium level. Initially, hypocalcemia produces paresthesia in the fingers, toes, and circumoral area that progresses to muscle tension and carpopedal spasms. The patient may also complain of muscle weakness, fatigue, and palpitations. Muscle twitching, hyperactive deep tendon reflexes, choreiform movements, and muscle cramps may also occur. The patient with chronic hypocalcemia may have mental status changes; diplopia; difficulty swallowing; abdominal cramps; dry, scaly skin; brittle nails; and thin, patchy scalp and eyebrow hair.
Other causes
Treatments
A massive blood transfusion can lower serum calcium levels and allow Chvostek’s sign to be elicited.
Special considerations
Collect blood samples for serial calcium studies to evaluate the severity of hypocalcemia and the effectiveness of therapy. Such therapy involves oral or I.V. calcium supplements. Also, look for Chvostek’s sign when evaluating a patient postoperatively.
Pediatric pointers
Because Chvostek’s sign may be observed in healthy infants, it isn’t elicited to detect neonatal tetany.
Geriatric pointers
Always consider malabsorption and poor nutritional status in the elderly patient with Chvostek’s sign and hypocalcemia.
Patient counseling
Inform patients who will be undergoing thyroidectomy or parathyroidectomy about the early signs and symptoms of hypocalcemia, such as numbness, tingling, and muscle cramps, and tell them to seek immediate medical attention if these
occur.
Pictures
Book Source Details
- Book Title: Signs & Symptoms: A 2-in-1 Reference for Nurses
- Author(s): Springhouse
- Year of Publication: 2007
- Copyright Details: Signs & Symptoms: A 2-in-1 Reference for Nurses, Copyright © 2007 Lippincott Williams & Wilkins.
Other Book Chapters Related to Hypocalcemia
Read excerpts from these other book chapters related to Hypocalcemia:
Medical Books Excerpts
- Carpopedal spasm
- "Alarming Signs and Symptoms: Lippincott Manual of Nursing Practice Series" (2007)
- [ read ]
Copyright Details: Signs & Symptoms: A 2-in-1 Reference for Nurses, Copyright © 2008 Williams & Wilkins.
More About Causes of Hypocalcemia
» Next page: Carpopedal spasm (Nursing: Interpreting Signs and Symptoms)
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