Idiopathic Carpal Spasm (Trousseau's Sign) After Intraoperative Arm Tourniquet Inflation in an Intubated Patient.

We present a case of a 38-year-old male who sustained a laceration from a knife to the volar aspect of his left index and middle fingers. He had clinical injury to his flexor digitorum profundus tendons to both digits. He underwent operative exploration and repair of the tendons under general anaesthetic. An arm tourniquet was inflated to allow for haemostasis in the operative field. A few minutes after inflation, the patient's hand went into carpal spasm. The tourniquet was deflated and the spasm resolved. Intraoperative serum calcium and carbon dioxide levels were normal. The operation proceeded with the tourniquet deflated. Postoperatively serum calcium and magnesium levels were within normal limits, as was serum vitamin D and parathyroid hormone levels. It has been reported that carpal spasm can occur with tourniquet use in the anxious patient due to hyperventilation and resultant metabolic alkalosis. This however is the first reported case of carpal spasm in the setting of tourniquet use and normal serum electrolytes and respiratory parameters in an intubated patient.