Trousseau Sign
The Trousseau sign is a physical symptom indicating a mineral deficiency in the body of a person. Typically, a mineral deficiency is detected through a blood test. However, if the deficiency is severe, it can cause some physical symptoms in the body. For example, a calcium deficiency can lead to a positive trousseau’s sign appearing as flexion of the wrist.
But what is the Trousseau sign? How is it caused? And what is its clinical significance?
We discuss all there is to know about Trousseau’s and its relation to the Chvostek sign in this post. You may also want to check out other nursing tips such as identifying HELLP syndrome, or performing a BUBBLE HE assessment.
What is the Trousseau Sign of Latent Tetany?
Named after French internist Dr. Armand Trousseau, the Trousseau sign of latent tetany is one of the few clinical signs associated with hypocalcemia. Hypocalcemia is the insufficiency of calcium in the blood.
First defined in 1861, the symptom refers to the carpopedal spasm (involuntary contraction of hand and wrist muscles) in patients with hypocalcemia when their upper arm is compressed with a blood pressure cuff for 3 minutes.
More specifically, Armand Trousseau stated that that cuff must be inflated to 20mmHg over their systolic pressure for 3 minutes for the symptom to appear.
The sign is sometimes referred to as “main d’accoucheur,” French for “hand of the obstetrician.” This is because the symptom resembles the hand positioning of obstetricians when they deliver babies.
What is the Difference Between Trousseau's Sign and Trousseau Symdrome?
It is necessary to differentiate Trousseau’s sign from Trousseau syndrome. The Trousseau syndrome, also called the Trousseau sign of malignancy or migrating thrombophlebitis, occurs when blood clots unexpectedly emerge in the superficial veins. These blood clots move to different locations in the body over time.
What is the Chvostek Sign?
In clinical medicine, Chvostek’s and Trousseau’s signs are the two of the most recognized signs of hypocalcemia.
While the Trousseau sign refers to the carpopedal spasm that appears when blood pressure is measured, the Chvostek sign refers to the twitching of the facial muscles when the patient’s cheek is tapped gently.
You can find images in clinical medicine of both of these signs on Google or in studies that appear in the Journal of Medicine.
How Does a Blood Pressure Cuff Cause Trousseau’s Sign?
The neurons of individuals with hypocalcemia are not as stable and fire more spontaneously than normal. Therefore, when the cuff is inflated on the patient’s arm, it reduces the arterial supply to the forearm by blocking the brachial artery. The neuronal irritability leads to tetany, which appears as spasms in the hand and wrist in the case of the Trousseau's.
In the case of the Chvostek sign, the increased neuromuscular excitability causes the muscles in the face to twitch when the facial nerve, located just in front of the ear, is tapped gently.
94% of patients with hypocalcemia show this symptom when the blood pressure is checked. That being said, between 1% and 4% of healthy individuals without a calcium deficiency show the Trousseau sign when checked.
Getting into the causes of hypocalcemia itself — the condition is most common in individuals that have a vitamin D deficiency or hypoparathyroidism.
However, hypocalcemia may also be caused due to severe infection, kidney failure, acute pancreatitis, or heavy medication. In addition, metabolic abnormalities such as alkalosis or a magnesium deficiency can also contribute to hypocalcemia.
How to Check for Trousseau’s
Medical professionals typically check for Trousseau’s sign when monitoring a patient’s vital signs.
As mentioned earlier, Trousseau’s is triggered when the sphygmomanometer cuff is placed on an individual’s arm and inflated to a higher pressure than their systolic pressure. By convention, the pressure is maintained at 20mmHg for between two and three minutes.
If the individual has a calcium deficiency, the wrist, thumb, and joints between the palm and fingers will flex involuntarily. This flexion is referred to as a positive Trousseau sign.
Issues of Concern
Hypocalcemia can be an indicator of numerous conditions with varying severity. The Trousseau sign may indicate:
- Hypomagnesemia or metabolic alkalosis, if the gastrointestinal system has lost a large volume of acid
- Vitamin D deficiency
- Parathyroid gland insufficiency
- Hemorrhagic shock
- Rhabdomyolysis
- Tumor lysis syndrome
- Sepsis
Clinical Significance of Trousseau’s Sign
When an individual comes to the emergency department or sees a doctor, vital signs are obtained first by convention.
If the Trousseau’s sign appears, the healthcare professional must make a note of it so the patient can have the issue addressed.
Making a note of the symptom is critical in settings where an allied health professional takes the patient’s vital signs. Communicating the sign’s appearance to the appointed clinician may be the patient’s only chance to address the issue.
Lindsay Smith
Lindsay is an Adult-Gerontology Primary Care Nurse Practitioner with Nephrology Associates in Nashville, Tennessee. She is passionate about working with patients with End-Stage Renal Disease (ESRD) to maximize their function and wellness.
