The following data refer to a 67-year-old male 8 days following initiation of treatment for acute leukaemia:
| Parameter | Patient Value | Normal Adult Range |
| Haemoglobin | 102 g/L* | 130 – 180 |
| White Cell Count | 111 x 109/L* | 4 – 11 |
| Platelets | 21 x 109/L* | 150 – 350 |
| Blasts | 100 x 109/L* | 0 |
| Sodium | 136 mmol/L | 136 – 145 |
| Potassium | 6.1 mmol/L* | 3.5 – 5.0 |
| Chloride | 95 mmol/L* | 98 – 106 |
| Bicarbonate | 17 mmol/L* | 23 – 28 |
| Urea | 21.8 mmol/L* | 2.9 – 7.1 |
| Creatinine | 209 μmol/L* | 60 – 120 |
| Calcium (corrected) | 2.48 mmol/L | 2.20 – 2.60 |
| Phosphate | 2.76 mmol/L* | 0.80 – 1.45 |
| Magnesium | 0.81 mmol/L | 0.60 – 1.10 |
| Urate | 0.84 mmol/L* | 0.20 – 0.42 |
| Total protein | 59 g/L* | 60 – 78 |
| Albumin | 27 g/L* | 35 – 55 |
| Bilirubin | 9 μmol/L | < 20 |
| Alkaline phosphatase (ALP) | 587 U/L* | 36 – 92 |
| Alanine transferase (ALT) | 42 U/L* | < 35 |
| Gamma glutamyl transferase (GGT) | 110 U/L* | < 30 |
| Lactate dehydrogenase (LDH) | 7157 U/L* | 60 – 100 |
a) Give the underlying cause of the above abnormalities and give your reasoning to explain these findings. (20% marks)
b) List the treatment options for this condition. (30% marks)
a)
Tumour lysis syndrome
Renal impairment with hyperkalaemia, hyperphosphataemia, hyperuraecamia and increased LDH
b)
Resuscitation – Adequate IV hydration
Treatment of hyperkalaemia – Calcium chloride, bicarbonate if ECG changes, dextrose- insulin, dialysis, resonium
Renal replacement therapy – metabolic acidosis, hyperkalaemia and hyperphosphataemia Allopurinol
Rasburicase
Let us dissect the results systematically.
The abnormalities and their potential explanations are:
The patient also has a white cell count of 111. This gives rise the the supicion that the hyperkalemia may be "pseudohyperkalemia of malignancy". The presence of haematological malignancy generally means a high white cell count; these extra cells are immature blasts which are structurally unsound, being exempt from normal cellular quality control mechanisms. The very act of aspirating these fragile cells into a syringe or vacutainer may give rise to wholesale cellular destruction by shear stress. The result is a falsely elevated potassium level. Kintzel and Scott presented a case report of this (2012) where the potassium level was 9.8mmol/L in the badly lysed sample and 4.1 mmol/L in the heparinised tube.
The treatment options are:
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Oda, Masako, et al. "Loss of urate oxidase activity in hominoids and its evolutionary implications." Molecular biology and evolution 19.5 (2002): 640-653.
Kintzel, Polly E., and William L. Scott. "Pseudohyperkalemia in a patient with chronic lymphoblastic leukemia and tumor lysis syndrome." Journal of Oncology Pharmacy Practice 18.4 (2012): 432-435.
Izumi, Masakazu, et al. "Increased serum alkaline phosphatase activity originating from neutrophilic leukocytes." Clinical chemistry 51.9 (2005): 1751-1752.