Diagnostic Tests for Oxygenation Disorders Flashcards
Diagnostic Tests for Oxygenation Disorders
- Arterial Blood Gases
- Pulse Oximetry
- Capnography and Capnometry
- Sputum Analysis
- Chest x-rays
- Pulmonary Function Tests
- Bronchoscopy
- Thoracentesis
- Lung Biopsy
Arterial Blood Gases
include: partial pressure of carbon dioxide (PaCO2), pH, bicarbonate (HCO3), and partial pressure of oxygen (PaO2), and SaO2
- blood gases are used to assess acid-base balance
- used to determine oxygenation status because PaO2 is the most accurate assessment, but pulse oximetry is an easier, non-invasive way to assess oxygenation
What do abnormal or low PaO2 levels indicate?
hypoxemia
What indicates an acid-base imbalance?
the bodys compensatory mechanism of increasing the respiratory rate in response to hypoxemia decreases PaCO2 value, impacting the acid-base balance
- higher CO2 levels indicate acidosis
- lower CO2 levels indicate alkalosis
Where is An ABG sample taken from?
directly from an artery through an arterial line or peripheral needle puncture
-usually via the radial or femoral artery, or through an indwelling arterial line or pulmonary artery catheter
ABG normal levels
- PaO2= 80 to 95 mmHg
- PaCO2= 35 to 45 mmHg
- pH= 7.35 to 7.45
- HCO3= 22 to 26 mEq/L
Pulse Oximetry
utilizes wavelengths of light to measure the saturation of hemoglobin with oxygen
- it is a noninvasive way to monitor changes in the patient’s oxygenation status
- can be used intermittently or continuously
Normal Pulse oximetry readings
between 95-99%
-below 95% may be someone with chronic respiratory distress
Nursing implications with Pulse Oximetry Readings
the nurse must confirm the accuracy of oximetry readings by evaluating the waveform and ensuring the pulse obtained through pulse oximetry correlates with the patients heart rate
- the patient experiencing carbon monoxide poisoning may have a pulse ox of 100%; but the hemoglobin is saturated with carbon dioxide not oxygen
- a person with a pulse ox of 100% with decreased hemoglobin level will still not have adequate tissue oxygenation
- place on finger, but earlobe, bridge of the nose, or the toe can be used
Capnography
continuously monitors the PaCO2 in the airway during inhalation and exhalation and provides a written tracing
Capnometry
measures the amount of CO2 exhaled without continuous tracing
Most valuable CO2 readings in capnometry device
is the end-tidal CO2 level
-measure the maximal partial pressure of CO2 obtained at the end of an exhaled breath
Abnormal capnography and capnometry values indicate what?
dysfunction of the respiratory system expelling CO2
Increase end-tidal CO2 levels may be from what?
an increase in cellular metabolism, resulting in an increased CO2 production or hyperventilation that causes an increase in the exertion of CO2 from the lungs
Disease processes that that result in increased CO2 levels are
hyperthermia, trauma, burns, and sepsis
Decrease in end-tidal CO2 levels result from what?
inadequate ventilation, respiration, or pulmonary perfusion
-conditions that cause this are slow cellular metabolism, resulting in less CO2 production; hypoventilation, resulting in a decrease excretion of CO2 from the lungs; and finally, conditions that cause an increase in alveolar dead space and shunt, which causes inadequate pulmonary capillary perfusion; this limits the diffusion of CO2 into the alveoli, that results in lower end-tidal CO2 levels
Where can Capnography devices be applied?
to the end of an artificial airway or noninvasive oxygen delivery device such as a nonrebreather mask
-device should be calibrated and zeroed
Capnometry is typically utilized for what?
endotracheal tube placement after intubation
- it is applied to the end of the endotracheal tube
- the device will show a color change to blue, indicating the presence of CO2 and intubation of the trachea
Sputum Analysis
is done to check for microorganisms and/or abnormal cell growth
- if microorganisms are indicated, then a sensitivity test is performed to determine effective antibiotic therapy
- if abnormal cells are identified, analysis to determine if the cells are malignant or non-malignant is indicated
What does a sputum analysis positive for microorganisms indicate?
indicates the presence of an infectious process such as TB or pneumonia
What does the presence of abnormal cells indicate in a sputum analysis?
a malignancy
How to collect a sputum culture for someone with a natural airway
- will be given a sterile collection device and asked to cough and deposit expectorated sputum into the container
- prior to the collection, patients should rinse the mouth to limit the contamination of normal mouth flora in the culture
- patients should be structured to collect sputum as early in the morning as possible because secretions accumulate overnight, increasing the volume of sputum collected and increasing the potential to identify microorganisms
- during the collection, the patient to be instructed to deeply inspire and expire, with the patient coughing during expiration
How to collect sputum culture with someone from a endotracheal tube or tracheostomy?
collected by suctioning the airway and placing the contents into a sterile collection device
-suctioning may cause discomfort
Patient who require suctioning for the collection of a sputum sample will require what?
hyperoxygenation prior to suctioning
- once the patient is hyper-oxygenated, the nurse inserts the suction catheter connected to suction into the tracheostomy or endotracheal tube utilizing sterile technique
- during the procedure the nurse monitors respiratory rate and heart rate
- if vital sign abnormalities are noted, the procedure is stopped and the patient is hyper-oxygenated until the vitals return to baseline
Chest x-rays
diagnostic studies of the thorax that may identify problems with the lungs, heart, and pleural space
-normally the first-line diagnostic test for patients with respiratory complaints because they are widely available and relatively inexpensive
What will a chest x-ray show?
will show if there are abnormalities of the heart or lungs
- for the heart, chest x-rays are only able to identify the size, shape, or placement of the heart ; if abnormalities are noted, additional diagnostic tests are indicated
- for the lungs, chest x-rays identify masses, air or fluid in the pleural space, pneumonia, atelectasis, and possible TB infections; many times, additional diagnostic tests are needed to confirm chest x-ray results; for example, a chest x-ray may identify possible TB, which is confirmed with a positive sputum culture
What can a chest x-ray show when evaluating the heart?
chest x-rays are only able to identify the size, shape, or placement of the heart; if abnormalities are noted, additional diagnostic tests are indicated
What can a chest x-ray show when evaluating the lungs?
chest x-rays can identify masses, air or fluid in the pleural space, pneumonia, atelectasis, and possible TB infections
-many times, additional diagnostic tests are needed to confirm chest x-ray results; for example: a chest x-ray may identify possible TB, which is confirmed with a positive sputum cultures
Patient preparation before a chest x-ray
- remove any necklaces or jewelry that covers the neck or thorax
- remove bra
- any metal objects will obscure the view of the chest and thus the x-ray image
Nursing implications regarding chest x-rays
- remove metal; necklaces and jewelry, and bra
- drape all body areas not being x-rayed in a lead shield to minimize radiation exposure
- women who are pregnant should receive education regarding the risk to fetus prior
Pulmonary Function Tests
evaluate lung volumes to determine the functioning of the lungs
- the patient is asked to inspire and exhale into a mouthpiece
- during the test, the patient is given instructions to alter his or her breathing patterns, allowing for different tests to be obtained
- before the test, normal values based on gender, weight, height, and smoking history are calculated to ensure accuracy of the readings
What do pulmonary function test values aid in?
the diagnosis of respiratory condtions
Patient preparation for Pulmonary Function Tests
- needs to refrain from smoking and eating for 8 hours
- patient should abstain from bronchodilators (beta 2- agonists) for 4 to 6 hours prior to the test
Nursing Implications for a patient for a Pulmonary Function Test
patient should be carefully monitored during the test to avoid any complications such as SOB or bronchospasm
Bronchoscopy
allows for direct visualization of the respiratory tract down to the level of the secondary bronchi
-the two types of bronchoscopy is flexible and rigid; flexible are used to take tissue specimens or replace an endotracheal tube, rigid is used to remove obstructions or large amounts of secretions from respiratory tract
Flexible Bronchoscopy
used to take tissue specimens or replace an endotracheal tube
-can be performed at the bedside with the patient receiving moderate sedation
Rigid Bronchoscopy
used to remove obstructions or large amounts of secretions from respiratory tract
-requires general anesthesia and is performed in the OR
Bronchoscopy abnormal findings help assist in?
diagnosis of respiratory conditions
-tissue specimens are analyzed to determine the presence of infectious processes or cellular abnormalities
Patient preparation for a bronchoscopy
because of the invasive nature of the procedure, patient consent should be obtained
-because of the need for sedation and the risk for aspiration, patients should not eat (remain NPO) for at least 8 hours prior to the procedure
Nursing Implications for a bronchoscopy procedure
prior to the procedure, the nurse should ensure that the appropriate consents have been signed and that the time-out procedure has been completed; the time-out should confirm the patients identity and the procedure being performed
Moderate sedation involves what?
giving the patient an IV pain medications and sedative
- depending on protocol, sedation may be administered by a nurse who has received specialized training in moderate sedation or an advanced practiced nurse (certified nurse anesthetist)
- patients who are moderately sedated are able to respond to verbal stimuli or gentle touch
What will a patient need for flexible and rigid bronchoscopies?
IV access and continuous cardiac monitoring, pulse oximetry, and blood pressure monitoring
-prior to starting, the nurse or OR staff needs to ensure that all emergency equipment is available at the bedside including oxygen and suctioning
During the recovery period of a bronchoscopy what should the nurse do?
assess for complications of the procedure, such as bleeding or hypoxia, and should remain NPO until patient is alert and gag reflex is intact
Thoracentesis
can be used as a diagnostic test or treatment depending on the disease process
- a needle is inserted into the pleural space to remove excess fluid/air
- can be used as a treatment option to remove fluid and/or air from the pleural space
Thoracentesis: What happens if fluid is aspirated from the pleural space?
it can be analyzed to determine if microorganisms or abnormal cells are present
Thoracentesis: What happens if air is aspirated from the pleural space?
this is consistent with a pneumothorax diagnosis
Patient preparation for a thoracentesis
the patient needs to sign a consent form and be informed of the benefits and risks of the procedure
-normally completed under local anesthesia, so the patient is fully awake during the procedure; instructed not to move but to remain as still as possible
-patient is placed to a sitting position, with a bedside table in-front of them, and the patient leans against the table
the need to cough is normal and advised to try to deep breathe to avoid coughing
Nursing Implications for thoracentesis
prior to starting, the nurse ensures that the patient signed appropriate consent forms and that a time-out procedure is completed
- assist client to a seated position on the side of the bed with the bedside table in front of them
- assess for potential complications that may arise during the procedure by monitoring vital signs and pulse ox
- the output from the site should be monitored because excess (more then 500 mL) may cause hypotension
- most patients that report SOB prior, report immediate relief of symptoms once fluid or air is removed
What does the nurse do at the end of a thoracentesis procedure?
reevaluate vital signs and lung sounds to assess for possible pneumothorax
- a chest x-ray should also be obtained because of high risk of pneumothorax
- the patient should be encouraged to cough and deep breathe following the procedure to decrease the risk of atelectasis and promote good lung expansion
Patients should report these symptoms after a thoracentesis
- elevated heart rate/ heart palpitations
- dyspnea/ SOB
- chest pain
- hemoptysis (bloody secretions)
Education regarding wound care following a thoracentesis
a dry sterile dressing is applied to the site
- the area should be assessed for drainage and bleeding immediately following the procedure and before discharge
- a minimal amount of blood noted is normal
Lung Bopsy
allows for a small piece of lung tissue to be removed an analyzed under a microscope
- can be performed percutaneously or through an open procedure
- type of biopsy performed is based on the location and size of the tissue requiring biposy
When is a lung biopsy ordered?
to confirm lung cancer, sarcoidosis, or pulmonary fibrosis
Abnormal values of a lung biopsy indicate what?
an infectious process or malignancy
Patient Preparation for a lung biopsy
patients receiving an open biopsy will need to be NPO for at least 8 hours prior because they will be receiving general anesthesia
- patient will need to be educated about the post operative period (open biopsies require the use of a chest tube in postop period)
- depending on type of open biopsy performed and the patients respiratory function, the patient may require intubation and mechanical ventilation in post op period
Nursing Implications for a lung biopsy
for percutaneous and open biopsies, there must be consent from the patient, and a time-out should be performed
Nursing Implications for percutaneous biopsies
assist the patient to a position that is utilized for a thoracentesis
- patient will receive local anesthetic injected at site of biopsy
- during the procedure, monitor vitals signs, pulse ox, for any complications
- remind patient not to move or cough during procedure
Nursing Implications for open lung biopsy
patients will receive general anesthesia and will be monitored by a anesthesiologist during procedure
-a thoracotomy will be performed, which will require a chest tube to allow for re-expansion of the lungs; the nurse will monitor the patient during post op period to assess for complications arising from he surgery and aesthesia
