Basingstoke and north hampshire hospital pathology user handbook

Reference Ranges and Turnaround Times

Please refer to the test index. These are also available on the ward enquiry computer terminals alongside the results.

Sample storage and Time Limit for requesting Additional Tests

The laboratory stores blood samples for 48 hours after the final report has been issued.

Requests for retrospective testing on blood samples is not recommended but will be considered if the request is made within 36 hours of sample collection.

Samples that may be required for further investigations or forensic reasons can be stored for several months but it is important that a specific request is made by the doctor to the laboratory staff to keep such samples.

Telephoned Results
Results falling below the lower limit or above the upper limit given in table below will be telephoned.

Analyte	Lower action limit	Upper action limit
Sodium (mmol/L)	125	155
Potassium (mmol/L)	2.8	6.0 (see below)
Glucose (mmol/L)	2.5	25.0
Urea (mmol/L)		30.0 (OPD/GP or in-patient 1^st result) 10.0 if patient less than 16yrs old
Creatinine (umol/L)		400 (OPD/GP or in-patient 1^st result) 200 if patient less than 16 yrs old
Calcium-corrected (mmol/L)	1.80	3.20
Phosphate (mmol/L)	0.30
Magnesium (mmol/L)	0.40
AST (IU/L)		800
ALT (IU/L)		800
Bilirubin (umol/L)		300 (Paediatric only)
CK (IU/L)		3000
Amylase (IU/L)		500 (OPD/GP or in-patient 1^st result)
Digoxin (ug/L)		3.0
Phenytoin (mg/L)		25
Theophylline (mg/L)		25
Phenobarbitone (mg/L)		70
Carbamazepine (mg/L)		15
Lithium (mmol/L)		1.2
Triglycerides (mmol/L)		20.0
CRP (mg/L)		400 (OPD/GP or in-patient 1^st result)
Free T3 (pmol/L)		30
Free T4 (pmol/L)	5
Cortisol (When not post dex) (nmol/L)	100
Troponin (ug/L)		0.05 (GP/OPD only)
Ammonia (umol/L)		100 (Neonate 0 – 3 days 47 (> 3 days, 1^st result)
Bile Acids (umol/L)		14.0

Useful clinical information - Common causes of spurious results

Please ensure that you follow instructions when collecting and storing samples. Inappropriate sample collection, storage and transport can interfere with a number of results. Some examples are given in the table below:

Problem	Common causes	Effect
Inappropriate collection site	Sample taken from drip arm	Increased drip analyte e.g. K , Glucose Dilution effect, low results
Incorrect container or anticoagulant	No fluoride oxalate	Decreased glucose
	E.D.T.A. contamination	Decreased Ca and Alk P Increased K
	Li sample collected into Li Heparin	Increased Li
Incorrect tube fill/mixing		ALL analytes may be compromised
Delay in separation of serum/plasma	overnight storage delay in transit	Increased K, PO4, LDH
Labile analytes	Not immediately separated and frozen	Decreased ACTH, Insulin, C Peptide and Gastrin
Storage	Biochemistry samples in a fridge	Increased K
Haemolysis	Expelling blood through a needle into the tube Vigorous shaking Extremes of temperature	Increased K, PO4, AST, LDH, Iron, Par, CPK, TP, Trig Decreased AMY, ALP

Andrology

The Andrology Laboratory is an integral part of the Fertility Service offered within this hospital. Andrology investigations include basic semen analysis and semen assessment following vasectomy.

Reference values for semen assessment are defined by the World Health Organization: Manual for the Examination and processing of Human Semen (FIFTH EDITION) 2009 and have been generated from several prospective, cross-sectional studies of semen quality and fertility. The attached table provides lower reference values of semen characteristics of recent fathers, whose partner became pregnant within 12 months of stopping use of contraception.

Parameter	Lower reference mean
Semen volume (ml)	>1.5
Total sperm number (106 per ejaculate)	>39
Sperm concentration (106 per ml)	>15
Total motility (PR+ NP, %)	>40
Progressive motility (PR, %)	>32
Sperm morphology (normal forms, %)	>4
pH	≥ 7.2
*MAR test (motile spermatozoa with bound particles, %) <50% reported as negative >50% positive)	< 50
**Vitality (live spermatozoa, %)	>58

Cooper TG et al. (2009) World Health Organization reference values for human semen characteristics. Human Reproduction Update.

High viscosity samples can interfere with sperm motility and concentration

*The mixed anti-globulin reaction or MAR test uses IgG- coated latex particles and anti-serum to human IgG. In the presence of spermatozoa with IgG antibodies the spermatozoa adhere to the latex particles. WHO considers that testing for IgG antibodies is adequate, since IgA antibodies almost never occur with out IgG antibodies. Low sperm concentrations and / or reduced sperm motility can give unrepresentative results and will not be reported.

**Test only performed if the number of immotile sperm is greater than 50%
It is important to note that semen characteristics are highly variable, both within and among men, and are not the sole determinants of a couple’s fertility; the ranges therefore provide only a guide to a man’s fertility status.

THE SERVICE:

• 
  The Fertility laboratory has been a CPA enrolled laboratory since 2005
  
• 
  Member of the UK national NEQAS quality control scheme since 1998
  
• 
  Samples are received by appointment only, enabling prompt analysis within a limited time window
  
• 
  Early morning appointments are available, offering as little disruption as possible in a friendly, relaxed surroundings
  
• 
  The Fertility department is open between 08.30am and 15.00pm Monday to Thursday with a 24hr answering service to pick up messages
  
• 
  Client confidentiality and wellbeing is paramount
  
• 
  Samples are initially analysed within one hour of receipt and generally reported within 3 working days
  

For further information, specimen requirements and request forms please contact:
Denise Riddell MSc FIBMS

Senior Biomedical Scientist Andrology Unit

Tel: [phone] E- mail: [e-mail]