Hey there! Sign in to join this conversationNew here? Join for free to post

hypocapnia, hypocalcemia and great flexion in wrists

Announcements Posted on
Four hours left to win £100 of Amazon vouchers!! Don't miss out! Take our short survey to enter 24-10-2016
REMINDER: Do not post your personal statement on TSR, otherwise you may have to rewrite it from scratch. Click here for more info. 12-10-2016
    • Thread Starter

    Why would hypocapnia cause hypocalcemia, and then cause great flexion in wrists?

    Hyperventilation > blows of CO2 > hypocapnia > respiratory alkalosis > increased binding of ionised calcium to serum proteins because of increased pH > less free ionised calcium available in the serum > hypocalcaemia > increased excitability of nerves > carpopedal spasm.

    Search Google images for "main d'accoucheur" (hand of the obstetrician) for the classical appearance of carpopedal spasm in hypocalcaemia. I remember seeing an otherwise-well patient on ITU whose only complaint was that both wrists were resting in this position. She was in ITU after a bleed following an elective operation and had subsequently received a massive blood transfusion - the citrate added to packed red cells sequesters calcium ions and so can lead to a similar set of signs as acute hypocapnia.

    (Original post by kesun)
    Why would hypocapnia cause hypocalcemia, and then cause great flexion in wrists?
    Name:  screen_shot_2013-12-10_at_105132_pm-142DFC91F90262559B9.png
Views: 62
Size:  15.4 KB

    Something about large calcium ions being unavailable to block sodium ion entry to thus cause nerve depolarisation also rings a bell. Meh.
Write a reply…


Submit reply


Thanks for posting! You just need to create an account in order to submit the post
  1. this can't be left blank
    that username has been taken, please choose another Forgotten your password?
  2. this can't be left blank
    this email is already registered. Forgotten your password?
  3. this can't be left blank

    6 characters or longer with both numbers and letters is safer

  4. this can't be left empty
    your full birthday is required
  1. Oops, you need to agree to our Ts&Cs to register
  2. Slide to join now Processing…

Updated: May 2, 2016
TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

What do wear to bed?

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.