Laboratory Urgent Investigations

Study Notes

Laboratories should be consulted and samples flagged as urgent if test results are required immediately to alter patient's clinical management.
Panic limits are highly abnormal test results that indicate a potentially life-threatening condition, requiring immediate contact with medical staff.

Consider whether the result is correct for the patient.
Check if the result fits with clinical findings; treat the patient, not just the laboratory numbers.
If it's the first time the test has been performed, check if the result is normal with the appropriate reference range.
If the result is abnormal, determine if it's diagnostically significant or non-specific.
If it's one of a series of results, check for changes and their clinical significance.
Abnormal results, especially if unexpected, should be repeated.

Monitoring is necessary when clinical response is not enough to determine treatment effectiveness (e.g., renal failure).
Tumor markers are measured serially during cancer treatment.

Measurements can be done for medico-legal reasons (e.g., drug levels in athletes, poisoning cases).
Research is necessary for medical advancements, but consent must be obtained from participants.

The frequency of investigations depends on how quickly significant changes are likely to occur and if changes will alter treatment.

Laboratory investigations are rarely needed more than once daily, except in intensive therapy cases.
Only essential tests should be repeated if done frequently.

Pathology is the study of normal states to detect abnormal conditions.
Chemical pathology (also known as Clinical Chemistry, Clinical Biochemistry, etc.) applies chemistry, biochemistry, and other fields to study human disease.
Chemical pathology measures biochemical substances in body fluids to detect abnormality and disease risk.

Substances include proteins, carbohydrates, lipids, minerals, vitamins, enzymes, and hormones.
Measurements assess organ function (e.g., liver, kidneys, heart, lungs, gastrointestinal tract, endocrine system, skin, bone, and brain).
Measurements can indicate risk of impending disease in these organs.