Certified Pediatric Emergency Nurse (CPEN) Practice Exam

Which lab tests are crucial in the assessment of poisoning?

1. Urinalysis and complete blood count

2. Blood toxicology screen and serum electrolytes

3. Chest X-ray and CT scan

4. Urine culture and drug screen

The correct answer is: Blood toxicology screen and serum electrolytes

The assessment of poisoning is critical in emergency settings, and certain lab tests provide key information to guide treatment and management. A blood toxicology screen is essential as it helps identify the specific substances involved in the poisoning, which is crucial for determining the appropriate antidotes or interventions. This test can detect a wide array of drugs and toxins in the bloodstream, enabling healthcare providers to tailor treatment to the specific poisoned agent. Serum electrolytes are also vital in this context because many toxic ingestions can lead to significant metabolic derangements, such as alterations in sodium, potassium, calcium, and bicarbonate levels. Monitoring these electrolytes is important for recognizing complications like arrhythmias or renal failure, which can arise from certain poisons. In contrast, other tests like urinalysis and complete blood count, while useful for general health assessments, do not specifically address the immediate needs related to poison identification or severe metabolic disturbances that can arise from poisoning. Imaging studies like chest X-rays and CT scans may provide insight into structural injuries or specific foreign bodies but do not directly assess for toxicological emergencies. Urine cultures are typically reserved for infections and do not aid in the assessment of poisoning situations. Therefore, the combination of a blood toxicology screen and serum electrolytes encompasses the