This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: JIPMER 2017, Subject name: Pediatrics
A 6 - year - old boy with lymphoreticular malignancy has come for a cycle of chemotherapy. Which of the following investigatins need to be done for next 4 hours to diagnose tumour lysis syndrome? 
Select and explain. 
A. Urea, creatinine, chloride, Ca2+ and K+, B. Urea, creatinine, phosphate, Ca2+ and K+, C. Urea, creatinine, magnesium, Ca2+ and K+, D. Urea, creatinine, sodium and phosphate
B: Urea, creatinine, phosphate, Ca2+ and K+
Answer: B: Urea, creatinine, phosphate, Ca2+ and K+ 
Explanation: Tumour lysis syndrome (TLS) - -Uric acid, phosphate and potassium are released in large quantities from death of tumour cells. -Hyperuricemia can lead to impairment of renal function, which fuher exacerbates the metabolic abnormalities. -Hypocalcaemia is a consequence of acute hyperphosphatemia with subsequent precipitation of calcium phosphate in soft tissues. 'TLS can occur before therapy in patients with a large tumour burden (e.g., Burkitt lymphoma, Hyperleukocytosis) It is usually seen within 12-48 hr of initiating chemotherapy.