Hyperventilation

what is the mechanism of a muscle spasm and why does the person have pain?

carpopedal spasms are pretty specific to a condition called hypocalcemia (low serum blood calcium). i saw these spasms once during my career in a post thyroidectomy patient and the poor woman was in absolute agony, a world of pain and scared to death. if you've ever had a charley horse you have an idea what a muscle spasm feels like. the surgeon had accidentally removed one of the parathyroid glands during the surgery causing the sudden drop in calcium and this is how the condition was discovered. we ended up giving her iv injections of calcium and her spasms stopped most dramatically. she is on calcium replacement for the remainder of her natural life.

calcium is needed for blood coagulation, the activation of many enzymes, the maintenance of acid-base balance, for the rigidness of teeth and bone, lactation, the function of nerves and muscles (particularly the heart), and cell membrane permeability. vitamin d is needed for the body to absorb and activate calcium for use by the body. calcium is also an electrolyte where about half of it circulates in the blood as a usable ion and must be constantly replaced by what we ingest through eating (foods that are high in calcium include natural foods such as many of the dried legumes and vegetables, salmon, tofu, rhubarb, sardines, collard greens, spinach, turnip greens, okra, white beans, baked beans, broccoli, peas, brussels sprouts, sesame seeds, bok choy, almonds). the other half of calcium in the body is stored in the teeth and bones. the calcium ion in circulation can be lost through the renal track and any calcium entering the gi track can exit through the intestines. therefore, it can be depleted very rapidly and must be constantly replaced. the parathyroid glands help to maintain the balance between the calcium that is stored in places like teeth and bone and the blood. if that balance is interrupted in some way (ex: renal failure, cirrhosis, hypoparathyroidism, malabsorption, vitamin d deficiency) then hypocalcemia results. other symptoms of hypocalcemia are:

• cardiovascular
  
  • arrhythmias
    
  • hypotension
    

  [*]gi

  • increased gi motility
    
  • diarrhea
    

  [*]musculoskeletal

  • paresthesias (may increase in severity and spread up the arms and to the face, leading to numbness, muscle spasms, and pain)
    
  • tetany
    
  • painful tonic muscle spasms
    
  • facial spasms
    
  • abdominal cramps
    
  • muscle cramps
    
  • spasmodic contractions
    

  [*]neurologic

  • anxiety
    
  • irritability
    
  • twitching around the mouth
    
  • laryngospasm
    
  • seizures
    
  • chvostek's sign - tapping the person just in front of the earlobe and below the zygomatic arch and the corner of the mouth will produce twitching of that corner of the mouth to twitching of all facial muscles on that side of the face
    
  • trousseau's sign - a blood pressure cuff is inflated to between the diastolic and systolic pressures and allowed to remain inflated for 3 minutes while watching the patient for evidence of carpal spasm in that arm which is positive evidence of trousseau's sign
    

  [*]blood clotting abnormalities

  [*]fractures may occur because of the loss of calcium from the bones