Clinical diagnostics is diagnosis made on the basis of knowledge obtained by medical history and physical examination, sometimes without benefit of laboratory tests or x-rays.
CLINICAL DIAGNOSTIC PRODUCTS
This contains a great deal of information about the patient which is extremely helpful for medical professionals. It includes medical history of the patient, medical history of the patient’s family and test results throughout the patient’s life. The chart can be shared by different medical professionals to better understand the patient.
Essential clinical diagnostic equipment includes the following;
• Hammer, brush and needle
• Tongue depressor
• Weighing scale
Positron emission tomography (PET) is a nuclear medicine imaging technique which produces a three-dimensional image of processes in the body. This is accomplished by injecting such substances as glucose or oxygen into the bloodstream after they have been labelled with special indicators called radioscopes. These radioscopes emit positrons that can be detected by a scanner. The information is then converted into a coloured diagram by a computer. The diagram shows tissue activity and this can be used to detect brain tumours.
These diagnostic products use sound waves to retrieve information about soft or fluid-filled tissues. It is ineffective in areas of the body surrounded by bone or containing gas. Ultrasound is used to determine information about a foetus, gallstones or thyroid cysts.
This method uses electromagnetic radiation to produce images of bones, organs and tissues. It is one of the most widely used diagnostic methods; however, exposure can be hazardous.
Magnetic resonance images (MRI’s) is another diagnostic product. It is a large scanner which produces cross-sectional or three-dimensional images of the body. To do this the scanner uses a powerful electromagnet and a radio wave detector. The patient who is undergoing an MRI scan is slid into the machine. It is used to examine such parts of the body as the brain, inner eye or tendons.
Medical professionals, such as doctors, will physically examine a patient before using any of the aforementioned machines. The purpose of the examination is to detect any physical signs of disease or illness, and investigating the patient’s problem. This may involve taking the patient’s temperature, blood pressure, listening to the patient’s heart etc. After the physical examination, if there are no problems detected the further methods may be considered, such as blood tests, urine tests, MRI scan, ECG etc.
In the initial examination the doctor will follow a number of procedures to identify the problem the patient is complaining of, this sequence is as follows;
• physical examination
• selection of laboratory tests and interpretation of results
• use of diagnostic facilities, e.g. X-ray, ultrasound
• processing of answers, findings or other results
Medical History Taking
A medical history is as follows;
• history of complaint
• review of systems (systemic inquiry)
• past history
• social history
• family history
• drug history
The medical professional will ask the patient questions in order to gain this information, which is then made into a record for future reference. Some questions which may be asked include the following;
• Where is the pain?
• Does it spread elsewhere?
• How severe is it? Does it prevent you from going about your daily activities?
• What is the pain? (Stabbing, burning, dull, etc?)
• How long have you had this pain?
METHODS/TECHNIQUES USED IN A DIAGNOSTIC PROCEDURE
This is the consideration of all possible causes/reasons for a patient’s complaint, weighing them up, doing medical tests which correspond with the possibilities and then process of elimination. This can help rule out any life threatening conditions.
This is the detection of a familiar pattern of clinical characteristics that the medical professional might recognise due to their experience in the field or their education.
This is when the medical professional determines the correct diagnostics through the use of an already constructed combination of signs, symptoms and test results. This is in the format of a guide.
Clinical Decision Support Systems
These are computer programs which are interactive. The medical professional can utilise these programs in order to aid decision-making. This essentially combines the knowledge of the medical professional with the computer software, resulting in better decision-making than either of them could achieve independently. The computer suggest options for the medical professional and the medical professional chooses information he/she deems useful and removes erroneous suggestions.
Some of these laboratory methods are aforementioned but the following physiological and/or behavioural conditions of the patient which may influence laboratory methods include the following;
• genetic and ethnic disposition
• geographical factors
• biorhythmic fluctuations
• physical exercise
• use of drugs and traditional medicines
Medical algorithms can be used by medical professionals. Another method which may be used is a process known as the “exhaustive method” where all possible questions asked and all possible information is collected.
The three processes involved in the diagnostic investigation are as follows
• Pre-analytical phase
• Analytical phase
• Post-analytical phase
The pre-analytical phase includes the time and processes for the preparation of a patient for a diagnostic investigation up to the time when the investigation is made. The analytical phase includes the time and all processes of a diagnostic investigation. The post-analytical phase includes the time and processes involved for reporting the results of the diagnostic investigation to the person who then undertakes the medical management of the patient. The medical professional must take great care in ensuring that no errors are made during each of these phases as these errors influence the diagnostic report’s clinical relevance.
CLINICAL DIAGNOSTICS – THE FUTURE
Pharmacogenomics Research Advances
Pharmacogenomics uses knowledge of the patient genetic profile to give information which will be used to decide treatment. It is possible that it may hold the key to the future of drug research.
A biomarker is a characteristic that is objectively measured or evaluated as an indicator of a normal biologic process, a pathogenic process or a pharmacological response to a therapeutic intervention. Newly determined biomarkers in clinical diagnostics will probably become an interdependent dynamic between new diagnostics and new drugs.
Comprehensive Disease Management Programs
These programs will monitor a patient’s disease progression and influence decisions about treatment options through better clinical assessments. It will take into account a patient’s well-being and quality of life, drug treatment and other services.
Changing Market Dynamics
New medicines to treat extended diseases will mean that the market will evolve. As the population grows, the demand for drugs and diagnostics will also increase.