Sunday, 29 April 2007

LMQA - External Quality Control Systems

Hey guys,

So far, i have found some information regarding external QC systems. Apparently, it's more of getting external companies to review your systems from what i understand. I might be wrong, do let me know your input.

I've complied it as below:

External Quality Control Systems (EQAS)


[ISO/REMCO N. 231, 1991]
External quality assessment (EQA) refers to a system of objectively checking laboratory results by means of an external agency, including comparison of a laboratory’s results at intervals with those of other laboratories, the main objective being the establishment of trueness.


To ensure the reliability of test results between different laboratories- Required by CLIA for laboratory accreditation- Provide a check on internal quality control- Detect errors in a lab's methods- Provides comparison of different testing methods to determine best suitable one.


To improve and standardize the quality of accuracy and precision via:
- Improvement of analytical capabilities
- Standardization [inter-laboratory comparability]
- Introduction of a world-wide efficiency proficiency testing system.

Key issues

• Samples:
– Sample state [Stable for the period of the exercise]
– Real or commutable
– characterize sample, maintain database
– Different endogenous/ spiked content covering the range of concentrations of interest

• Regular frequency; Panel preparation
–Select sample for retest

• Sample distribution
– Coordinate shipping, review sample state, documentation

• Resources
– Lab facilities, staff, equipments, lab layout, materials

• Data analysis including:
– methods to identify deviations from normal distribution
– methods to identify outliers or robust statistics

• Performance evaluation


- Standards set by WHO, or Relevant health organizations/associations (CSAP, CLIA etc).

- Used to evaluate the accuracy of participating laboratory routine testing methods in adhering to standardized test methods.

- Several (8-10) bacterial/viral strains/clinical samples are sent out to participating laboratories annually.

- For stereotyping or antimicrobial susceptibility testing to be done

- Laboratories will report their findings to WHO

- WHO will determine how accurate the findings are in correlation to their own true results

- The evaluations of the laboratory testing systems will be sent to them in individual reports
o Mean results of sample analysis
o Number of labs using same method
o Standard deviation index
o Lower and upper limits of acceptability of results
o standard deviation of results by the comparative method

- Used to determine if their routine methods are up to standard or need to be rectified.

- must be tested with the laboratory's regular patient load (in Clinical Laboratories context)
- number of times that patients' samples are tested routinely should not differ from when participating in external quality control programme/system
- Laboratories in external quality control programme must not compare results with each other.
- Laboratories may not send samples to another company for analysis
- All steps carried out must be documented accordingly

EVALUATION (external quality control review):

Report or evaluation sent:

- contain transmittal letter
- standardized language
- opinion paragraph
- required/supporting exhibits

May be from:
- 1 organisation (WHO)
- Peer evaluation (in some unions such as EU), in participating countries.

Generally 3 types of opinions:

1) Unmodified Opinion
- Issued when the review team finds company’s quality control system to be adequate and designed properly

2) Modified Opinion
- Issued when quality control system did not function satisfactorily as prescribed, causing significant deficiencies

3) Adverse Opinion
- Issued when quality control system was inadequate as prescribed, not functioning adequately

Disclaimer opinion
- may be present when review team could not successfully assess some procedures due to limiting conditions present.


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



Wednesday, 25 April 2007

MMic - Tutorial 1-4 solution


List of good websites

Suspected Disease

1) Thypus:

2) Zoonotic Diseases:

3) Flea-borne diseases:

4) Scabies:

5) Brucellosis:



Our group's expectations.

Our group of 6 consisting of Cheng Hong, Debra, Elaine, Eunice, Pei Shan and Yeng Ting, all from Tg02 aim to act as a cohesive team and aspire to work together well, for the benefit of ourselves and one another in our shared learning journey.

We hope that through our different exposures that are inevitable to come from our SIPs will enable us to impart and learn from one another via blog postings. We also hope to use this as a method of continued communication of important information during SIP whereby we will probably see each other less. As such, this will become an anchor of sort, or imformation hub, as a neccessary reminder of school during SIP.

Although this blog is majorly intended for communication during SIP for exchange of knowledge, prior to that in our first 6 weeks of this semester, we intend to use this to post our group soloutions for all subjects as per stated for both the lecturer's and our future reference. We hope to establish a line of communication here with the lecturers as well so that we can gain feedback and better improve ourselves.