OVERVIEW OF CHEMICAL PATHOLOGY AND USES OF BIOCHEMICAL.pptx

CHEMICAL PATHOLOGY AND USES OF BIOCHEMICAL INVESITIGATIONS PROFESSOR ADEKUNLE BASHIRU OKESINA HEAD DEPARTMENT OF CHEMICAL PAHOLOGY AND IMMUNOLOGY, UNIVERSITY OF ILORIN. OVERVIEW OF CHEMICAL PATHOLGY AND IMMUNOLOGY  CH...

CHEMICAL PATHOLOGY AND USES OF BIOCHEMICAL INVESITIGATIONS PROFESSOR ADEKUNLE BASHIRU OKESINA HEAD DEPARTMENT OF CHEMICAL PAHOLOGY AND IMMUNOLOGY, UNIVERSITY OF ILORIN. OVERVIEW OF CHEMICAL PATHOLGY AND IMMUNOLOGY  CHEMICAL PAHOLOGY and IMMUNOLGY subjects are introduced to Medical Students at the University of Ilorin at 400L  Students are expected to have attained a good level of understanding of the basic medical sciences ; Anatomy, Physiology and Biochemistry which will serve as foundation for understanding of pathology in general. Where a substantial deficit exists in the knowledge of candidate in these basic sciences he must read them concurrently during this posting so as to be able to understand the pathology OVERVIEW OF CHEMICAL PATHOLGY AND IMMUNOLOGY  It will be thought as block posting with the other pathology subjects in three blocks referred to as block 1(INTORODUCTORY), block 11 and block 111 postings.  In addition to bullet 2 in the previous slide, students are expected to have been exposed to introductory clinical clerkship during which they have been put through the simple techniques of history, physical examination which will prompt appropriate clinical laboratory investigations in order to make a diagnosis. If not so, there is need to concurently do some introductory clinical clerkship for proper understanding of pathology OVERVIEW CONTS. WHAT IS PATHOLOGY  Pathologyis the study, using measurements or detections of substances in tissues and body fluids to identify abnormal physiology, anatomy and biochemistry at the gross anatomical level, biochemical level and molecular level in order to indicate presence or rule out disease in a patient and when diseases are present to determine the severity, response to treatment and presence of complication. OVERVIEW CONTS. WHAT IS PATHOLOGY  In summary, pathology is the study of normal in order to detect presence of abnormal state. WHAT IS CHEMICAL PATHOLOGY  Chemical pathology has been given different names depending on the institution. Such names include: Clinical Chemistry, Clinical Biochemistry, Clinical Pathology etc. and defined as the diagnostic application of chemistry, biochemistry, immunochemistry, biochemical of haematology, toxicology and molecular biology to the study of human disease in body tissues, fluids and cells.  In chemical pathology, we measure level of biochemical substances in the body fluids as a means of pointing out abnormality which will indicate presence or increased risk of disease in an WHAT IS CHEMICAL PATHOLOGY  Substances measured include the three major food substances such as protein, carbonhydrate and lipids. Also, minerals, vitamins, enzymes and hormones are measured.  We use combination of these measurements to assess function of organs such as: liver, kidneys, heart,lungs Gastrointestinal, endocrine, skin, bone and brain  Sometimes the measurement may indicate risk of impending disease of these organs. REASONS FOR BIOCHEMICAL LABORTATORY INVESTIGATIONS  Screening when indicated  diagnosis  monitortreatment or detect complications,  medicolegal reasons  research SCREENING  Patient with symptoms pointing towards a particular disorder: tests may be performed to confirm diagnosis or rule out presence of disease. There are some age related conditions that may indicate such screening in certain group of individuals  Population screening for common metabolic diseases: e.g diabetes mellitus using measurement of fasting blood glucose (FBG) or glycated haemoglobin.  Inborn errors of metabolism: many disorders are inherited and if allowed to establish may lead to permanent damage in the child. Many countries have therefore put in place screening programmes of all newborn babies to detect those with such problems so that treatment can be commenced before permanent damage occurs. A good example is hypothyroidism which is not uncommon if allowed to establish will cause permanent brain damage in the child. In this environment another important disease is sickle cell disease. DIAGNOSIS  Symptoms may point to particular type of disorder and unless diagnostic test is carried out, the doctor will not be able to confirm that patient is suffering from that particular disease and appropriate treatment instituted. An example is a case of thyroid disorders which may develop in a very gradual manner and measurement of thyroid hormones will be required to make the diagnosis. If for instance that student starts performing poorly in class or an increase in sleeping pattern is noticed. It may be due to hypothyroidism which can be treated. DIAGNOSIS  Sometimes a patient is sick and the cause of the illness is not immediately obvious. Test will be ordered to determine the ailment the patients is suffering from ie diagnosis of the disease. For example a patient may present in comma. A good history, and clinical examination will point to various differential diagnosis, however, a good clinician will collect blood and urine samples before starting treatment so as not to miss an important biochemical diagnosis which may be life saving for the patient at the point of treatment. Also, it will prevent future episode because appropriate therapeutic measures will be put in place. A good example is that of a patient in coma due to hypoglycaemia. MONITORING OF TREATMENT AND DETECTION OF COMPLICATIONS  Many times during treatment patient will require biochemical tests to be carried out to monitor response to treatment. Several treatments fall into these category clinician cannot always rely on clinical response during treatment because it may be too late to prevent catastrophe in the patient. For example, in patients with renal failure on treatment, the only way to know the response is to monitor serum levels of urea and creatinine. Some tumour markers are measured serially during treatment of such cancers. MEDICOLEGAL AND RESEARCH  MEDICOLEGAL REASONS Measurement are sometimes carried out for medico legal reasons. Measurement of drug levels among sports men. Also, in cases when poison is suspected.  RESEARCH For advancement in medical practice research has to be carried out to determine the best option for management of patient. However, consent must be secured from participants before data from them can be used for research. HOW OFTEN MUST I INVESTIGATE MY PATIENTS? This depends on the following:  How quickly numerically significant changes are likely to occur: for example, concentrations of the main plasma protein fractions are unlikely to change significantly in less than a week, similarly for plasma thyroid- stimulating hormone.  Whether a change, even if numerically significant, will alter treatment: for example, plasma transaminase activities may alter within 24 h in the course of acute hepatitis, but, once the diagnosis has been made, this is unlikely to affect treatment. By contrast, plasma potassium concentrations may alter rapidly in patients given large doses of diuretics and these alterations may indicate the need to instigate or change treatment. Laboratory investigations are very rarely needed more than once daily, except in some patients receiving intensive therapy. If they are, only those that are essential should be repeated. WHEN IS THE INVESTIGATION URGENT?  The main reason for asking for an investigation to be performed ‘urgently’ is that an early answer will alter the patient’s clinical management. This is rarely the case and laboratory staff should be consulted and the sample ‘flagged’ as clearly urgent if the test is required immediately.  Laboratories usually have ‘panic limits’, when highly abnormal test results indicate a potentially life threatening condition that necessitates contacting the relevant medical staff immediately. To do so, laboratory staff must have accurate information about the location of the patient and the person to notify. RESULT INTERPRETATION HOW? Ask the following questions:  Is the result the correct one for the patient?  Does the result fit with the clinical findings? Remember to treat the patient and not the ‘laboratory numbers’. RESULT INTERPRETATION HOW? Cont.  If it is the first time the test has been performed on this patient, is the result normal when the appropriate reference range is taken into account?  If the result is abnormal, is the abnormality of diagnostic significance or is it a non-specific finding?  If it is one of a series of results, has there been a change and, if so, is this change clinically significant?  Abnormal results, particularly if unexpected and indicating the need for clinical intervention, are best repeated. THE END THANKS FOR LISTENING AND WELCOME TO PATHOLOGY