In this section of the NCLEX-RN examination, you will be expected to demonstrate your knowledge and skills of diagnostic tests in order to:

  • Apply knowledge of related nursing procedures and psychomotor skills when caring for clients undergoing diagnostic testing
  • Compare client diagnostic findings with pre-test results
  • Perform diagnostic testing (e.g., electrocardiogram, oxygen saturation, glucose monitoring)
  • Perform fetal heart monitoring
  • Monitor results of maternal and fetal diagnostic tests (e.g., non-stress test, amniocentesis, ultrasound)
  • Monitor the results of diagnostic testing and intervene as needed

Applying a Knowledge of Related Nursing Procedures and Psychomotor Skills When Caring for Clients Undergoing Diagnostic Testing

Diagnostic tests can be invasive and noninvasive. Registered nurses perform some aspects of both noninvasive and invasive diagnostic tests such as an ECG and a blood sample for blood glucose testing, for example.

Regardless of the nature of the diagnostic test, some of the general rule and procedures relating to all client diagnostic tests include:

  • The verification of the doctor's order for the particular diagnostic test
  • The verification and validation of the client's identity using at least two unique identifiers
  • Providing the client and/or significant others with an explanation of the diagnostic test, the purpose of the diagnostic tests and the procedure that will be followed for the specific diagnostic test, in addition to any specific preparation such as NPO after midnight, as indicated for the particular diagnostic test
  • The verification of the client's consent to the diagnostic test, as indicated
  • The proper adherence to universal precautions, medical or surgical asepsis as indicated by the type of the diagnostic test
  • Proper handwashing before and after each specimen collection and/or bedside diagnostic testing
  • The proper, complete and accurate labeling of all specimens that are obtained by the nurse at the bedside that minimally includes the client's full name, the date and time of the specimen collection
  • The proper preservation and transportation of the specimen to the laboratory in a timely manner along with the proper laboratory requisition slip
  • The use of the proper receptacle or container for the specific specimen that contains any necessary preservatives, chemical or anticoagulants
  • The proper disposal of all supplies and equipment that was used for the diagnostic test

Performing an Electrocardiogram (EKG/ECG)

An electrocardiogram traces the electrical activity of the heart over a period to time with an electrocardiograph which is connected to the patient with the external application of electrocardiogram leads. The procedure for performing a 12 lead electrocardiogram is:

  • Assist the client into a comfortable supine position
  • Ask the client to remain as still as possible while the ECG is being done
  • Expose the client's chest, lower legs and lower arms
  • Cleanse the skin and allow it to dry in the areas that the leads will be placed

The chest or precordial leads are placed as show below:


The limb leads are placed as shown below:Limbs

  • Secure the electrodes to flat areas on each of the patient's extremities above wrists and ankles
  • Place the other six electrodes on the chest in the correct areas.
  • Run the ECG strip
  • Print the electrocardiogram data off and then place it into the client's medical record, according to the particular facility's policy or procedure
  • Notify the doctor of any unexpected or abnormal findings

Oxygen Saturation

Oxygen saturation reflects the amount of oxygen saturation in arterial blood. It is measured and monitored by placing a sensor on a client's finger or, when necessary, on their forehead, nose, or ear. Oxygen saturation levels are often checked with the same frequency as the patient's vital signs using a pulse oximeter and this noninvasive procedure can be done by trained and competent certified nursing assistants in the same manner that they can take and record patients' vital signs.

Fecal Occult Blood

Fecal occult blood testing, also referred to as guaiac screening, is a screening tool for colon cancer and it is also used as part of the diagnostic tests used to determine the source of anemia that can be related to a gastrointestinal bleed.

Fecal occult blood testing is done by collecting two small portions of the patient's stool and placing them on a commercially prepared slide. A drop of reagent liquid is then placed on the slide. The test is positive for occult hidden blood when the slide turns blue within 60 seconds.

Blood Glucose Monitoring

The procedure for checking the client's blood glucose levels is as follows:

  • Verify and confirm that the code strip corresponds to the meter code.
  • Disinfect the client's finger with an alcohol swab.
  • Prick the side of the finger using the lancet.
  • Turn the finger down so the blood will drop with gravity.
  • Wipe off the first drop of blood using sterile gauze.
  • Collect the next drop on the test strip.
  • Hold the gauze on the client's finger after the specimen has been obtained.
  • Read the client's blood glucose level on the monitor.

Routine Stool Specimens

The procedure for collecting routine stool specimens is as follows.

  • Get the proper container for the stool specimen.
  • Ask the patient to void before the stool specimen is collected so that the stool is not mixed with any urine.
  • Ask the patient to eliminate their stool in a clean bedpan, bedside commode, or in the toilet using a high hat.
  • Collect the specimen.
  • Tighten the lid on stool specimen container.
  • Label the specimen with the data that is required according to your facility's policy and procedure.
  • Transport the specimen to the laboratory as quickly as possible.

Routine Urine Specimens

The procedure for collecting a routine urine specimen is to:

  • Get the proper container for the urine specimen.
  • Ask the patient to void into a clean bedpan, a bedside commode, or on the toilet using a high hat.
  • Tighten the lid on the receptacle after the specimen is obtained.
  • Label the specimen with the data that is required according to your facility's policy and procedure.
  • Transport the specimen to the laboratory as quickly as possible.

Obtaining a Clean Catch or Midstream Urine Specimen

Collecting a clean catch or midstream urine specimen varies among the genders. Males should cleanse the penis from the urinary meatus to the peripheral area using a circular pattern and using only one disposable antiseptic wipe for each swipe. Females should use one antiseptic wipe for each swipe from the front to the back and from the inner labia to the outer labia. Then,

  • Ask the patient to void a small amount of urine into the toilet without collecting it.
  • Then ask the patient to void into the laboratory collection bottle.
  • Tighten the lid on the receptacle and use a disinfectant to clean the outside of container.
  • Transport the specimen to the laboratory as quickly as possible.

Obtaining a Timed Urine Specimen Such as a 24 Hour Urine

Timed urine specimens are collected during a specified period of time, as indicated in the doctor's order. For example, urine is collected for a full day when a twenty 24 hour urine specimen is ordered. Nurses will then collect all urine passed during this period of time or they will ask the patient to collect all voided urine so that the nurse can place it into the correct urine collection container. When the duration of collection has been reached, all the collected urine is then labeled and delivered to the diagnostic laboratory for testing.

Obtaining a Sputum Specimen

Sputum specimens are collected by providing the patient with a specimen collection container and asking the client to deep breath, cough and expel sputum into the container. They should also be instructed to not allow saliva into the container. Once the specimen is collected, it is then labeled and delivered to the diagnostic laboratory for testing.

Collecting a Throat Culture

  • Instruct the client to open mouth widely and then stick their tongue out.
  • Insert the sterile swab into the back and wipe across tonsil area, pharynx, or any other region that is red, swollen, or contains exudate.
  • Place the swab into the specimen container, tighten the lid and send it to the laboratory.

Nurses educate clients about the purposes, required preparation, procedures, results and the implications of abnormal and normal diagnostic tests including the results of all laboratory tests and testing.

Performing Fetal Heart Monitoring

Fetal heart monitoring was fully discussed previously under "Checking and Monitoring the Fetal Heart during Routine Prenatal Exams and During Labor".

Monitoring the Results of Maternal and Fetal Diagnostic Tests

The results of maternal and fetal diagnostic tests such as a non-stress test, amniocentesis and ultrasound was fully discussed previously under "Providing Prenatal Care and Education".

Monitoring the Results of Diagnostic Testing and Intervening as Needed

Throughout the course of care, nurses monitor the results of diagnostic tests and modify the plan of care, as indicated. They also notify the physician when laboratory results are outside of normal limits and/or a significant change for the client.


SEE - Reduction of Risk Potential Practice Test Questions