Lecture on Trousseau's Sign

Speaker: Sarah from NurseRN.com

What is Trousseau's Sign?

• A specific type of muscle spasm in the hand and wrist
• Due to neuromuscular irritability
• Indicative sign of low calcium in the blood (hypocalcemia)
• Can also be caused by low magnesium levels in the blood

Assessing for Trousseau's Sign

• Look for a positive or negative sign
  • Positive: Patient has Trousseau's sign
  • Negative: Patient does not
• Required Equipment: Manual blood pressure cuff
• Key Factor: Be aware of the patient's latest systolic blood pressure reading (top number)

Steps to Assess:

1. Place the blood pressure cuff on the patient's arm.
2. Inflate the cuff to a pressure greater than the patient's systolic blood pressure.
3. Hold the pressure for about three minutes.
4. Observe the hand and wrist on the arm with the cuff:
   • Positive Sign: Hand draws inward, flexion at wrist, thumb, and MCP joints; fingers remain extended.
   • Negative Sign: No reaction occurs.

Why Does Trousseau's Sign Occur?

• Inflating the cuff occludes the brachial artery
• The brachial artery supplies blood to the forearm, wrist, and hand
• Low calcium levels make nerves and muscles irritable and overexcited
• Occluding blood flow (ischemia) triggers muscle spasms in those structures

Conclusion

• Understanding Trousseau's sign is important for diagnosing hypocalcemia
• For more review lectures, refer to the link in the YouTube description below