CHAPTER 15

1. CHAPTER 15 INTRODUCTION TO THE CLINICAL LABORATORY

2. PRETEST True or False • When the body is in homeostasis, an imbalance exists in the body. • A routine test is performed to assist in the early detection of disease. • The laboratory request form provides the outside laboratory with information needed to test the specimen. • The clinical diagnosis is indicated on a laboratory request to correlate laboratory data with the needs of the physician. • The purpose of a laboratory report is to indicate the patient's diagnosis.

3. PRETEST, CONT. True or False • A patient who is fasting in preparation for a laboratory test is permitted to drink diet soda. • A small sample taken from the body to represent the nature of the whole is known as a specimen. • A laboratory report marked QNS means that the patient did not prepare properly. • Fecal occult blood testing is an example of a CLIA-waived test. • The purpose of quality control is to prevent accidents in the laboratory.

4. Content Outline Laboratory tests: Used along with the health history and physical examination to diagnose patient's condition Laboratory tests: Provide objective and quantitative information regarding status of body conditions and functions Introduction to Clinical Laboratory

5. Introduction to Clinical Laboratory 2. Homeostasis:state in which body systems are functioning normally Internal environment of the body is in equilibrium Body is in a healthy state Normal or reference range:An established range within which laboratory test results of a normal person are expected to fall

6. Introduction to Clinical Laboratory, cont. 4. Body in homeostasis: • Physical and chemical characteristics of body substances fall within normal range • Body substances include: • Fluids • Secretions • Excretions

7. Introduction to Clinical Laboratory, cont. 5. Pathologic condition: • Alters the normal functioning of the body • Results in imbalance in the body • Causes patient to experience symptoms of that particular pathologic condition (e.g., iron-deficiency anemia)

8. Introduction to Clinical Laboratory, cont. • May cause alteration in body substances • Chemical content of blood or urine • Antibody level • Cell counts • Cellular morphology • May result in abnormal values laboratory test results • Certain pathologic conditions cause abnormal values for specific laboratory tests

9. Introduction to Clinical Laboratory, cont. 6. Abnormal value for a particular test: may be seen with more than one pathologic condition • Example: Decrease in hemoglobin levels seen with: • Iron-deficiency anemia • Hyperthyroidism • Cirrhosis of the liver

10. Introduction to Clinical Laboratory, cont. • Physician cannot rely solely on laboratory tests to make a final diagnosis • Must use a combination of data from: • Health history • Physical examination • Laboratory/diagnostic test results

11. Laboratory Tests • Number of tests ordered: depends on physician's clinical findings (health history and physical examination) • May only need to order one test (e.g., urine culture for a urinary tract infection) • May need to order a series of tests to diagnose a condition • Many diseases have more than one alteration in: • Physical and chemical characteristics of body substances

12. Laboratory Tests, cont. • Not all pathologic conditions require use of laboratory tests to arrive at a final diagnosis • Diagnosis can be made from patient's symptoms and physical examination (e.g., otitis media) • MA should have knowledge of laboratory tests performed most often • Purpose of tests • Normal value or range

13. Laboratory Tests, cont. • Advance patient preparation or special instructions • Any substances that might interfere with accurate test results • Food • Medication • Make sure physician is alerted to abnormal results on laboratory tests as soon as possible

14. Purpose of Laboratory Testing • Assist in diagnosis of pathologic conditions: most frequent use of laboratory tests • Confirm clinical diagnosis • Clinical diagnosis: A tentative diagnosis of a patient's condition obtained through evaluation of the: • Health history • Physical examination • Patient's symptoms may provide strong clinical diagnosis (e.g., diabetes) • Laboratory tests are used to confirm that diagnosis (glucose tolerance test)

15. Purpose of Laboratory Testing, cont. • Assist in differential diagnosis • Two or more diseases may have similar symptoms • Laboratory tests ordered to determine which disease is present

16. Purpose of Laboratory Testing, cont. • Obtain information regarding patient's condition • May not be enough evidence to support a clinical diagnosis • Patient may be exhibiting vague symptoms • Example: Nonspecific abdominal pain • Series of laboratory and diagnostic tests ordered to pinpoint cause of patient's problems

17. Purpose of Laboratory Testing, cont. • Evaluate patient's progress and to regulate treatment: after making the final diagnosis • Based on laboratory results: therapy may need to be adjusted or further treatment prescribed • Examples: • Complete blood count on patient with iron-deficiency anemia to assess response to iron therapy • Adjusting Coumadin therapy based on results on physical therapy (PT) test

18. Purpose of Laboratory Testing, cont. • Establish patient's baseline • Age, gender, race, geographic location: cause individuals to have different normal levels within established normal range • Laboratory tests establish each patient's baseline against which future results can be compared

19. Purpose of Laboratory Testing, cont. • Prevent or reduce the severity of disease by early detection of abnormal findings (e.g., hyperlipidemia, anemia, diabetes) • Known as a routine test: a test performed on a routine basis on apparently healthy patients to assist in the early detection of disease • Easy to perform • Usually part of general physical examination

20. Purpose of Laboratory Testing, cont. • Common routine tests • Urinalysis • Complete blood count (CBC) • Cholesterol • Routine blood chemistries

21. Purpose of Laboratory Testing, cont. • Requirement by state law • Example: Statutes of most states require gonorrhea and syphilis tests be performed on pregnant women • Purpose: to protect mother and fetus from harm

22. Types of Clinical Laboratories • Medical office may use outside laboratory or have its own laboratory (physician's office laboratory) • Most offices use a combination of both Physician's Office Laboratory (POL) • For tests that are convenient to perform and commonly required (e.g., glucose, urinalysis) • Time-consuming and expensive to perform complex tests in the office

23. Outside Laboratories • MA works closely with outside laboratory • Outside laboratories include: • Hospital laboratories • Privately owned commercial laboratories • Laboratory provides office with supplies and forms to collect and prepare specimens for transport • MA responsible for checking and reordering supplies

24. Laboratory Directory • Reference source for proper collection and handling of specimens • Provided to office by outside laboratory

25. Laboratory Directory, cont. • Information included: • Names of tests performed by laboratory • Normal range for each test • Instructions on completion of forms (e.g., laboratory request) • Patient preparation required for each test

26. Laboratory Directory, cont. • Supplies required for collection of each specimen • Amount and type of specimen required for each test • Techniques for collection of specimen • Proper handling and storage of specimen • Instructions for transporting specimen • If MA has any questions: Call laboratory

27. Laboratory Directory

28. Collection and Testing Categories • Categories: • Specimen collected and tested at office • Specimen collected at office and transferred to outside laboratory • Patient given laboratory request to have specimen collected and tested at outside laboratory • Responsibilities of MA depend on which method is used

29. Laboratory Requests Purpose • Laboratory request:Printed form containing a list of most frequently ordered laboratory tests a. Can be completed manually • MA writes in all required information b. Can be completed on a computer screen • MA enters information on a keyboard

30. Laboratory Requests, cont. 2. Required when a specimen is: • Collected at office and sent to outside laboratory for testing • Collected and tested at an outside laboratory • Request given to patient at office to take to laboratory

31. Laboratory Requests, cont. • Provides laboratory with information for: • Accurate testing • Reporting of results • Billing • Format of laboratory requests varies depending on laboratory

32. Laboratory Request Form

33. Parts of a Laboratory Request Form • Physician's name and address • Facilitates reporting of results to physician • May be preprinted on form

34. Parts of a Laboratory Request Form, cont. • Patient's name and address • Needed for: • Identifying report • Billing purposes

35. Parts of a Laboratory Request Form, cont. • Patient's age and gender • Normal ranges for some tests vary based on age and gender • Example: Hemoglobin • Female: 12 to 16 g/dL • Male: 14 to 18 g/dL

36. Parts of a Laboratory Request Form, cont. • Date and time of collection of specimen • Date: • Indicates number of days that have passed since specimen was collected • Provides information regarding freshness of specimen • Too long of a time lapse can result in inaccurate results

37. Parts of a Laboratory Request Form, cont. • Time: • Normal range for some tests vary based on whether test is an AM or a PM specimen

38. Parts of a Laboratory Request Form, cont. • Laboratory tests desired • Usually indicated by marking a box adjacent to tests • Mark box clearly • Space designated for additional tests is provided • Use to specify a test not listed on request form

39. Parts of a Laboratory Request Form, cont. • Profile: contains many laboratory tests • Profiles performed by laboratory and tests included in each: listed in laboratory directory • Specific profile: all tests relate to specific organ • Used when physician has a good idea of what organ is involved in patient's condition • Example: Hepatic profile tests assist in diagnosis of liver conditions

40. Parts of a Laboratory Request Form, cont. • General profile: contains routine laboratory tests • Used for routine health screens or when patient's symptoms are vague • Example: comprehensive metabolic profile

41. Laboratory Profiles

42. Laboratory Profiles

43. Parts of a Laboratory Request Form, cont. • Source of specimen (e.g., throat, wound, ear, eye, urine, vagina) • Tells laboratory where specimen came from • May not be possible to determine by looking at specimen • Method laboratory uses to test specimen: based on source of specimen

44. Parts of a Laboratory Request Form, cont. • Physician's clinical diagnosis • Assists the laboratory in correlating clinical laboratory data with the needs of physician • Further testing may be needed if one test method proves inconclusive • Alerts laboratory to possibility of presence of a dangerous pathogen (e.g., hepatitis) • Required for billing

45. Parts of a Laboratory Request Form, cont. • Medications • Certain medications may interfere with accuracy and validity of test results • Must be indicated on request to inform laboratory

46. Parts of a Laboratory Request Form, cont. • STAT • Performed as soon as possible • Results telephoned or faxed to office • Place completed request form with specimen for transport to laboratory • Without request: laboratory does not have info to carry out orders • Results in delay in completing tests and reporting results

47. Laboratory Reports • Purpose • Relay laboratory test results to physician • May be: a. Preprinted form: • Results are printed on form by computer b. Computer report • Entire report (tests and results) are printed by the computer

48. Laboratory Report

49. Laboratory Reports, cont. • Includes: • Name, address, and telephone number of laboratory • Physician's name and address • Patient's name, age, and gender • Patient's accession number • Provides positive identification of each specimen and access to patient's laboratory records

50. Laboratory Reports, cont. • Date specimen received by laboratory • Date results reported by laboratory • Names of tests performed • Results of tests