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	If sufficient specimen for cell block preparation.
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.