TTL tips 3: Giving Blood products? Think Calcium!

This is the third in series of short, case-based learning posts for trauma team leaders (TTL). These tips, based on our real-world experience with injured patients, will help you get the best out of your team when it matters most.

You are ten minutes into an intense resuscitation. The patient is a twenty-seven year-old stabbing victim, and you are trying to gain control of a major haemorrhage.

So far, six units of packed red blood cells have been given, alongside four units of fresh frozen plasma, tranexamic acid, and a platelet transfusion.

You notice that your patient has become bradycardic, and is making some strange wrist movements when the blood pressure cuff inflates. A repeat venous blood gas shows two severe electrolyte abnormalities.

You wonder why this has happened, and if there was anything you could done earlier to prevent it……

What is going on!

This patient has become hypocalcaemic and hyperkalaemic.

Unfortunately, calcium depletion is common in major trauma patients with acute traumatic coagulopathy, and this matters, because calcium is required for many of the reactions involved the coagulation cascade. We actually make the hypocalcaemia worse when we transfuse these patients. Packed red blood cells and FFP contain citrate, which binds and (thus depletes) free calcium.

Packed red blood cells also contain high levels of potassium: (it may be as high as approximately 20mmol/L !!)

The take-home message here is clear: bleeding patients need calcium. So here are some tips for managing hypocalcaemia as a trauma team leader. If you would rather read these on a PDF, click on the link below.

3 TTL tip calcium and MHP stemlyns Download

Check the gas…

The adjusted / corrected calcium level on the bone profile is not the “gold-standard” for diagnosing hypocalacemia. This is actually found on your venous or arterial blood gas! Blood gas analysers contain selective electrodes for calcium in its ionised form — which is the biologically active calcium that we care about.

Check the ionised calcium when the first calcium is done. A level below 1.0 is considered severe hypocalcaemia.

…and check it again!

Take serial blood gases as the resuscitation continues, and keep an eye on the calcium and potassium levels.

You may be focused on other results (e.g. lactate, Hb) but these electrolytes remain crucial!

Top your patient up

If you don’t have access to a blood gas then we recommend giving CaCl 10ml with every second two units (this is controversial though as there is no real consensus on this, follow your local protocol).

This should be 30ml of 10% calcium gluconate, or 10ml of 10% calcium chloride. The latter may be logistically easier, as it is found in most crash trolleys.

This will simultaneously address hypocalcaemia and the arrythmogenic effects of hyperkalaemia.