Turnaround times
The quoted turnaround time is from sample receipt in the laboratory, to results authorisation in the Laboratory Information Management system. The times do not include transport of specimen to the laboratory or the administrative process to print and post/email reports. Service users must allow for transport and reporting time when ordering tests.
Clinical background:
Pleural effusion:-In health, glucose diffuses freely across the pleural membrane and the pleural fluid glucose concentration is equivalent to blood. Although fluid glucose is usually low in pleural infection, it is a significantly less accurate indicator for chest fluid drainage than fluid pH. Rheumatoid arthritis is unlikely to be the cause of an effusion if fluid glucose is >1.6 mmol/L.
Peritoneal (ascitic) effusion:- Ascitic fluid glucose concentration should reflect the prevailing plasma concentration unless it is being metabolised by bacteria or white blood cells present in the fluid.
Specimen container paediatric:
Fluoride oxalate tube
Specimen container adult:
| Fluoride oxalate tube |
Minimum volume paediatric:
0.5 mL
Minimum volume adult:
0.5 mL
Special requirements:
Fluid in fluoride oxalate tube
Interpretation:
Pleural effusion:-
Pleural fluid glucose <3.4 mmol/L, clinical indication:- Complicated parapneumonic effusions, empyema, rheumatoid pleuritis, TB, malignancy, oesophageal rupture
Pleural fluid glucose <1.6 mmol/L, clinical indication:- Rheumatoid arthritis, empyema
Peritoneal (ascitic) effusion:-
Decreased ascitic fluid glucose has been reported in TB peritonitis, malignancy and spontaneous bacterial peritonitis. A fluid/blood glucose ratio of <0.7 is virtually diagnostic of TB ascites (100% sensitivity and specificity). (Bansal et al, 1998).
Factors affecting result:
Samples which are too viscous and/or contain particulate matter after centrifugation are unsuitable for analysis.