Friday, 27 April 2007

clinical chemistry case-study1&2


These are the answers for our CChem case-study

case study1:

•Age: 56 Gender: Male Ethnic: Indian
•Diagnosis: Suspected Lung Cancer
•Test requested: Blood gases
•Sample: Heparinzed syringe
•Sample collected: 9am Sample received in lab: 10am
•Sample upon received in lab: Not sent in ice and blood sample appeared dark red
•pH = 7.12 (7.35 – 7.45)
•pO2 = 50.0 mmHg (75.0 – 100)
•pCO2 = 50.0 mmHg (35.0 – 45.0)


•Absence of ice
>>Continued biological activity
---continued metabolism of RBC
---homocysteine produced
---embden-meyerhof(EM pathway) continues
>>2,3-DPG produced as side product by Luebering-Papport Shunt
>>2,3-DPG binds to hemoglobin, causes releases of oxygen from RBC, maintains deoxyl state
>>Hence, lower amount of oxygen(pO2 lower than average)
>>% of CO2 in blood increases, pCO2 content is higher than usual
>>Thus results in a more acidic pH values as stated.

Conclusion: His reading are invalid as his sample was not properly prepared for testing purpose

case study 2:

•Age: 23 Gender: Female Ethnic: Chinese
•Diagnosis: Routine check-up
•Test requested: Renal function test (Sample: Plain)
•Sample collected: 2pm Sample received: 2.30pm
•Comment: Sample is hemolyzed.
•Urea = 3.0mmol/L (2.8 – 7.7)
•Creatinine = 50umol/L (44 – 141)
•Sodium = 135 mmol/L (135 – 145)
•Potassium = 7.0 mmol/L (3.5 – 4.5)
•Bicarbonate = 20 mmol/L (19 – 31)
•Chloride = 110 mmol/L (96 – 108)


•Pseudohyperkalaemia à haemolysis
• Possible Reasons why trace of blood can be found in the urine sample:
>>Permeability of Gomerular
>>Infection occur at the urinary tract
>>Staff that collected the urine sample mishandled the sample, causing haemolysis

A trace amount of RBC is found in urine under normal conditions
>>High potassium level
---large amount of k+ inside RBC, when RBC in urine is lysed, K+ moves to the surrounding urine
>>High chlorine level
---CL- present in RBC (small amount)
---In RBC, HCO3- is pumped out from the cell, and CL- moves in which explains the high level of chlorine in urine when RBC is lysed

Therefore another test should be taken.
The sample sample should not be hemolyzed



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