Ionised calcium from blood gas measurements, often overlooked

Ionised hypocalcaemia in emergency and acute medicine

“…What might be causing clinicians to under-use the blood gas calcium?6 We suggest two cognitive biases. The first is a straightforward authority bias: omission of ionised calcium from expert guidelines1 may have led clinicians to regard the test as non-valued by experts.…”

“…Our interest was in studies using ionised calcium in the treatment or prognosis of patients in the emergency department or on acute medical wards. In total, 2585 records were screened and eight relevant articles were identified 6–13. Major trauma studies were excluded as comprehensive reviews have been published on ionised calcium in these settings 14 15…”

“…This may not be an uncommon occurrence. Kalidindi et al 6 found that only half of patients with ionised hypocalcaemia on their admission blood gas underwent treatment or repeat testing. In a subsample of patients described by Çap et al ,11 19 had ionised hypocalcaemia and a prolonged QT interval.…”

“…Modern blood gas machines now provide a rapid assessment of ionised calcium 3–5. However, this test is frequently under-valued in acute settings6 and is not included in major adult treatment guidelines (eg,1). Overall, the usefulness of ionised calcium is appreciated more in the literature than it is in clinical practice.…”