What is one of the urgent biochemical investigations that should be conducted immediately after a cardiac arrest?

Electrolytes and glucose are crucial biochemical investigations that should be performed immediately after a cardiac arrest because they provide essential information about the patient’s metabolic state and can significantly impact resuscitation efforts. After a cardiac arrest, abnormal levels of electrolytes—such as potassium, calcium, and sodium—can lead to life-threatening arrhythmias or contribute to the patient’s condition if not addressed promptly. Furthermore, measuring blood glucose is vital, as both hyperglycemia and hypoglycemia can adversely affect cardiac function and patient outcomes. These tests help guide immediate management and treatment decisions.

Other tests like a complete blood count (CBC), prothrombin time (PT), or thyroid function tests, while useful for assessing other aspects of a patient's health, do not provide the immediate and critical information needed to stabilize a patient right after a cardiac arrest. They are generally not prioritized in the urgent setting, where rapid assessment and correction of metabolic derangements take precedence.