Our personnel are responsible for ensuring that urgent cases are prioritised when specimens are received in the laboratory. In general, priority is given to specimens from the Emergency Department (ED), Intensive Care Unit (ICU/CCU), Acute Assessment Unit (AAU) and Operating Theatre (OT), followed by Specialist Outpatient Clinics (SOC), then Acute and Community Hospital (AHCH) wards.
Specimens from various locations can be easily distinguished by the colour of the specimen labels or bags:
-
Red: Emergency Department, Intensive Care Unit, Acute Assessment Unit (AAU)
and
Operating Theatre (OT)
-
Blue: Specialist Outpatient Clinics
-
White or clear: Acute and Community Hospital wards
- Please do not call the laboratory.
- Order test as STAT. Order status are captured by the laboratory automation system and prioritised for STAT test requests. For other specimen types other than blood, indicate ‘Urgent’ on the biohazard bag.
The turn-around time target for reporting urgent specimens is within
one hour from the reception of the specimen in the laboratory.
We send specimens for particular test requests out to external laboratories. These tests are usually either simple but uncommonly requested, or highly specialised. We plan to expand the range of tests we perform in future, if there is sufficient demand from clinical departments, or we have developed the necessary expertise.
There are specimens that are not handled by us and should be sent directly from the requesting location to the referral laboratories. If required, we can assist in arranging transport for these specimens. They include:
- Medico-legal specimens referred to Health Sciences Authority (HSA)
- Human Organ Transplant Act (HOTA) specimens referred to HSA
If specimens are not collected and transported to the laboratory according to the recommended procedures, we reserve the right to reject the specimens for testing.
LIST OF REASONS FOR SPECIMEN REJECTION
Clinical rejection criteria
- Insufficient or underfilled specimen
- Haemolysed specimen that is unsuitable for analysis
- Clotted specimen
- Overfilled citrated specimen
- Specimen container received as empty
- No specimen received with request form
- Unlabelled specimen
- Specimen leaked en route to laboratory and unsuitable for analysis
- Specimen not sent in ice and received after collection beyond stability period of analyte
- Air gap seen in ABG syringe
- Haematocrit >55%: citrate volume adjustment required for coagulation tests
- Test menu restriction for high risk specimen
- pH of 24-hour urine specimen received unsuitable for analysis, to send acid/plain urine specimen
- Missing identification
- Specimen is on defined exclusion list
- Formed stool unsuitable for testing
- Requested test unavailable
- Sputum culture rejected due to poor quality of specimen
- AFB tests rejected as CSF protein, glucose and WBC are within normal range
- Inability to perform analysis of specimen due to technical error
Administrative rejection criteria
- Specimen unsuitable for test requested
- Mismatch between request form and specimen
- No specimen collector's signature on patient's label for specimens requiring signature
- Specimen unsuitable for add-on test request
- No counter-signature on request form for requests requiring two signatures
- Duplicate test request within specified time-frame
- Request by clinician to cancel tests
- Orders received by laboratory at time beyond allowable period after specimen collection
- Test request only available during office hours or as specified, and specimen cannot be kept due to stability
- Duplicate request for specimens that must be collected on separate days
- Routine stool parasitology not indicated for patients hospitalised for more than 3 days
- Routine stool culture not indicated for patients hospitalised for more than 3 days
Non-recollectable specimens which do not comply with the specimen acceptance criteria may be analysed at the discretion of qualified and competent laboratory personnel, or by criteria specified by each laboratory section. Requesting clinician is required to come to the laboratory personally to verify the correct patient identification.
For any rectifications performed, an incident report is filed in PRISM. The test report must have a clear disclaimer detailing the shortcomings of the specimen and/or request, and the requestor will be held responsible for the results and for any action taken as a result of the report.
Radioactive specimens are
not accepted for testing.
Laboratory personnel inform the ordering clinician of the rejection via secured messaging system. During secured messaging system downtime, laboratory personnel call the ordering location and inform the nurse-in-charge.
Specimens received by the laboratory including rejected specimens are discarded and therefore not returned to requesting locations except for tissue specimens that are exempted from pathologic examination. Specimens listed in the Anatomic Pathology exclusion list will not be accepted by the laboratory but returned to the sending location for disposal.
ANATOMIC PATHOLOGY EXCLUSION LIST
The following specimens are exempted from histopathologic and cytopathologic examination, and should not be sent to the laboratory:
- Specimens for which a pathological examination does not contribute to patient care, and which are of no medico-legal significance, such as:
- Cataracts removed by phacoemulsification
- Rib segments or other tissues removed only for purposes of gaining surgical access in patient without a history of malignancy
- Saphenous vein segments harvested for coronary artery bypass
- Skin or other normal tissue removed during a cosmetic or reconstructive procedure, e.g. blepharoplasty, cleft palate repair, abdominoplasty, rhytidectomy, and syndactyly repair, provided that the specimen is not contiguous with a lesion and that the patient does not have a history of malignancy - Teeth without attached soft tissue - Normal toenails and fingernails that are incidentally removed - Middle ear ossicles
- Foreskin from circumcisions of newborns
- Fat removed by liposuction
- Bone segments removed as part of corrective or reconstructive orthopaedic procedures (e.g., rotator cuff repair, synostosis repair, spinal fusion)
- Non-pathologic amputation specimens
-
Traumatically injured and gangrenous members that have been amputated and for which pathologic examination for either medical or legal reasons is considered unnecessary
-
Dental appliances
-
Medical devices, such as catheters, gastrostomy tubes, myringotomy tubes, stents and sutures, that have not contributed to patient illness, injury or death
-
Foreign bodies, such as bullets, or other medico-legal evidence given directly to law enforcement personnel
-
Orthopaedic hardware and other radio-opaque mechanical devices since there is an alternative policy documenting their surgical removal.
-
Therapeutic radioactive sources
When in doubt, the clinician-in-charge should discuss the matter with the pathologist-in-charge of Histopathology.
The clinician-in-charge should ensure that there is an alternative procedure for documenting the removal and disposal of any specimen or devices not submitted to Anatomic Pathology for examination.
Add-on test requests are accepted
only for certain tests within the specified timing indicated and recommended by the manufacturer.
Add-on test requests involve a lot of work for laboratory personnel (i.e. retrieval of specimen, re-ordering of test, and re-analysis of specimen). Hence, add-on test requests should be made sparingly, and on the understanding that they are not routine practice. Add-on test requests are not considered urgent. If an urgent result is required, clinicians should order a new test and send a new specimen.
ADD-ON TEST LIST
| TEST NAME | ADD – ON TEST TIMING: FROM TIME OF SPECIMEN COLLECTION |
|---|
| Cytopathology - Fluids, non-gynaecology | If sufficient specimen for cell block preparation. |
| Cytopathology – FNA, Non-gyn (with and without cytotech assistance) | 2 weeks, if sufficient specimen for cell block preparation. |
| Cytopathology – Gyn liquid pap smear | If sufficient specimen for cell block preparation |
| Histopathology - Routine | Yes |
| 25-Hydroxy Vitamin D, Total | 24 hours |
| Acetaminophen (Paracetamol) | 24 hours |
| Alanine Transaminase | 24 hours |
| Albumin | 24 hours |
| Alkaline Phosphatase | 24 hours |
| Alphafetoprotein | 24 hours |
| Amikacin | 24 hours |
| Amylase | 24 hours |
| Aspartate Transaminase | 24 hours |
| Beta-Human Chorionic Gonadotropin, Total | 24 hours |
| Bilirubin, Direct | 24 hours |
| Bilirubin, Total | 24 hours
|
| C-Reactive Protein | 24 hours |
| Calcium Panel | 24 hours |
| Carbamazepine | 24 hours |
| Carcinoembryonic Antigen | 24 hours |
Cerebrospinal Fluid FEME
| 4 hours |
| Chloride | 24 hours |
| Cholesterol, Total | 24 hours |
| Creatine Kinase | 8 hours |
| Creatine Kinase - MB | 24 hours |
| Creatinine | 24 hours |
| Digoxin | 24 hours |
| Ferritin | 24 hours |
Fluid FEME
| 4 hours |
Joint Fluid FEME
| 4 hours |
Peritoneal Fluid FEME
| 4 hours |
Pleural Fluid FEME
| 4 hours |
| Folate | 24 hours |
| Gamma-Glutamyl Transferase | 24 hours |
| Gentamicin | 24 hours |
| Glucose | 4 hours |
| Glucose, CSF | 4 hours |
| HDL Cholesterol | 24 hours |
| Hepatitis A IgM Antibody | 24 hours |
| Hepatitis B Surface Antibody | 24 hours |
| Hepatitis B Surface Antigen | 24 hours |
| Hepatitis C Antibody | 24 hours |
| Iron | 24 hours |
| Iron Panel | 24 hours |
| Lactate Dehydrogenase | 24 hours |
| Lipid Panel | 24 hours |
| Liver Panel | 24 hours |
| Magnesium | 24 hours |
| Osmolality | 24 hours |
| Phenobarbital | 24 hours |
| Phenytoin | 24 hours |
| Phosphate | 24 hours |
| Potassium | 24 hours |
| Procalcitonin | 24 hours |
| Prostate-Specific Antigen | 24 hours |
| Renal Panel | 24 hours |
| Salicylate | 24 hours |
| Sodium | 24 hours |
| Testosterone, Total | 24 hours |
| Theophylline | 24 hours |
| Thyroid Panel | 24 hours |
| Thyroid-Stimulating Hormone | 24 hours |
| Thyroxine, Free | 24 hours |
| Total Protein | 24 hours |
| Total Protein, CSF | 4 hours |
| Total Protein, Fluid | 4 hours |
| Transferrin | 24 hours |
| Triglycerides | 24 hours |
| Troponin I, High-Sensitivity | 24 hours |
| Urea | 24 hours |
| Uric Acid | 24 hours |
| Valproic Acid | 24 hours |
| Vancomycin | 24 hours |
| Vitamin B12 | 24 hours |
| Activated Partial Thromboplastin Time (APTT) | • On unfractionated heparin (UFH): 2 hours • Not on unfractionated heparin (UFH): 4 hours |
| Activated Partial Thromboplastin Time (APTT) Mixing Study | On unfractionated heparin (UFH): 2 hours Not on unfractionated heparin (UFH): 4 hours |
| D-Dimer | 4 hours |
| DIC Screen | On unfractionated heparin (UFH): 2 hours Not on unfractionated heparin (UFH): 4 hours |
| Erythrocyte Sedimentation Rate (ESR) | 4 hours |
| Fibrinogen (FIB) | 4 hours |
| Full Blood Count | 4 hours |
| Malaria Parasite Screen | 4 hours |
| Microfilaria Microscopy | 4 hours |
| Peripheral Blood Film | 4 hours |
| Prothrombin Time (PT-INR) | 4 hours |
| Prothrombin Time (PT) Mixing Study | 2 hours |
| PT/APTT Profile | On unfractionated heparin (UFH): 2 hours Not on unfractionated heparin (UFH): 4 hours |
| Reticulocyte Count | 4 hours |
| Thrombin Clotting Time (TCT) | 4 hours |
| Cerebrospinal Fluid (CSF) Culture | 3 days |
| Ear Culture | 3 days |
| Eye Culture | 3 days |
| Fluid Culture | 3 days |
| Respiratory Culture | 3 days |
| Miscellaneous Culture | 3 days |
| Tissue Culture | 3 days |
| Wound Culture | 3 days
|
The laboratory does not accept requests for cancellation of recollectable specimens after they have been received by the laboratory. The only exemption to this is for mislabelled specimens and deceased patients, billing charged to requesting location.
For cancellation the requestor must complete the Cancellation form and send it to the laboratory. An incident report is filed in PRISM.