Download Bonewit: Clinical Procedures for Medical Assistants, 8

Bonewit: Clinical Procedures for Medical Assistants, 8th Edition
Chapter 12: Cardiopulmonary Procedures
1. Electrocardiograph:
2. Electrocardiogram (ECG):
3. Cardiovascular disorders;
a. Can cause abnormal changes on ECG
4. Purpose of electrocardiography:
a. Evaluate the following symptoms:
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•
•
•
b.
c.
d.
e.
f.
g.
h.
i.
j.
k.
5. ECG cannot detect all cardiovascular disorders
a. Cannot always detect impending heart disease (e.g., MI)
6. ECG is taken with patient in resting state
a. Only records 10 seconds of heart’s activity
•
If patient has an intermittent dysrhythmia
- May not occur during this brief time
a. Patient with angina pectoris
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Does not usually have symptoms in a resting state
- ECG may appear normal
7. To obtain a complete assessment of cardiac functioning
a. ECG must be used in combination with:
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•
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8. MA responsible for running ECG, which includes
a. Preparation of patient
b. Operation of electrocardiograph
c. Identification and elimination of artifacts
d. Care and maintenance of electrocardiograph
9. ECG machine formats
a. Single-channel format: one lead recorded at a time
b. Three-channel format: three leads recorded at one time
• Most offices use
Structure of the Heart
1. Heart consists of
a. Small upper chambers
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•
b. Large
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2. Pathway of blood through the heart
a.
•
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Brought back to heart after circulating in the body
Deoxygenated: contains very little oxygen and high in CO2
b.
c.
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By way of the
- In lungs
(1)
(2)
d.
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e.
f.
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Nourishes tissues with oxygen and nutrients
Conduction System of the Heart
1.
a. Located
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Just below opening of superior vena cava
b.
• Known as
a. Normal individual
• Generates impulse at rate of 60–100 times per minute
2. Path of impulse from SA node
a. Electrical impulse discharged by SA node
b. • Blood forced through cuspid valves and into ventricles
c. Impulse picked up
- Located at base of right atrium
d. AV node delays impulse momentarily
• Allows for:
e. Impulse transmitted
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Bundle of His is divided into
f. Bundle branches: relay impulse to the
g. Purkinje fibers: distribute
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Causes ventricles to contract
- Forces blood out of ventricles
(1) From right ventricle: blood is forced into pulmonary artery
(2) From left ventricle: blood is forced into aorta
(a) Causes BP and pulse to be produced
h.
i.
j. Cycle repeats
Cardiac Cycle
1. Represents
2. Consists of
a. Contraction
b. Contraction
c. Relaxation
3. ECG: records electrical activity that causes cardiac cycle to occur
4. ECG cycle: graphic representation of cardiac cycle
Waves
1. P wave
a.
b. Known as atrial depolarization
2. QRS complex (consists of Q, R, S waves)
a. Represents
•
Known as ventricular depolarization
b. Ventricles are larger than atria
• Requires a stronger electrical stimulus to depolarize ventricles
- Causes R wave to be taller than P wave
3. T wave
a.
• Known as ventricular repolarization
a. Muscle cells are recovering in preparation for another impulse
c. Atrial repolarization (electrical recovery of the atria)
• Occurs following P wave
• Occurs at same time as ventricular depolarization (QRS complex)
- Causes it to be masked by the QRS complex
- Therefore does not appear as a separate wave on ECG cycle
4. U wave
a.
b.
•
•
c. May be associated with repolarization
Positive deflection: wave deflects upward
Negative deflection: wave deflects downward
Electrocardiograph Leads Show students
1. Consists of
a. Lead:
2. Each lead:
a.
b.
•
Facilitates thorough interpretation of the heart’s activity
3. Electrode
a.
b.
•
Conducts impulse into the machine by lead wires
4. Four limb lead wires
a.
b.
c.
•
•
: ground
Not used for recording
Serves as an electrical reference point
d.
5. Chest lead wires
a. Abbreviated
b. Uses
Electrodes
1. Used to record a resting 12-lead electrocardiogram
2.
a.
1.
a.
•
1.
Contain a thin layer of a metallic substance
Good conductor of electricity
Square in shape
Tab extends from one end
Allows for firm attachment of alligator clip
Electrolyte gel combined with an adhesive
a. Located on back of electrode
•
Electrolyte: a substance that facilitates the transmission of the heart’s electrical impulse
Patient Preparation
1. Minimal preparation required for an ECG
2. Purpose
a.
Facilitate placement of electrodes
b.
Ensure good adhesion of the electrodes to the skin
1. Instruct patient in the following:
a.
Do not apply body lotion, oil, or powder on the day of test
• May make it more difficult to apply electrodes
a.
Wear comfortable clothing
b.
Wear a shirt or blouse that can easily be removed
c.
Women should not wear full-length hosiery (e.g., panty hose or tights)
Artifacts
1. Important to produce a clear and concise ECG
a. Can be read and interpreted by computer and physician
2. Occasionally artifacts appear in the recording
a. Artifact:
• Interferes with the normal appearance of ECG cycles
3. Affects quality of recording
• Makes it difficult to manually measure ECG cycles
4. May cause a false-positive ECG on ECGs analyzed by a computer
5. Artifacts must be identified and corrected by the MA
6. Most common artifacts
a.
b.
c.
7. If unable to correct artifacts: machine may be broken
a. Contact service technician with the following information
• What has already been done to locate and correct the problem
• Leads in which artifact occurs
• Sample of the artifact
Cardiac Dysrhythmias
1. Normal ECG: consists of
a. Repeats in a regular pattern
2. Normal sinus rhythm: ECG that is within normal limits
a. Waves, intervals, segments, and cardiac rate fall within normal range
3. Normal heart rate range:
4. Sinus bradycardia:
5. Sinus tachycardia:
6. Cardiac dysrhythmia:
a.
b.
7. Categories of cardiac dysrhythmias:
a.
b.
c.
8. MA should be able to identify dysrhythmias on ECG
a. Alert the physician
Premature Atrial Contraction
1. Description
a. Beat that comes before next normal beat is due
b. P wave has a different shape from P wave of normal beat
c. Normal QRS complex and T wave
2. Clinical significance
a. Common in healthy individuals
b. Often caused by intake of stimulants (caffeine, tobacco)
c. Also can be associated with
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Serious atrial dysrhythmias
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Structural heart disease
Paroxysmal Atrial Tachycardia
1. Description
a. Abrupt episode of tachycardia
b. Heart rate: 150 to 250 beats/min
c. Sudden onset and termination
d. Lasts only a few seconds, then heart rate returns to normal
e. ECG cycles are very close together
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As a result of increased heart rate
f. Patient experiences
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Sudden pounding or fluttering of chest
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Weakness and breathlessness
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Acute apprehension
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Occasionally may experience syncope
2. Clinical significance
a. One of most common rhythm disorders
b. Often occurs in healthy patients
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Especially young adults with normal hearts
c. Also can occur in patients with organic heart disease
Atrial Flutter
1. Description
a. Rapid regular fluttering of the atrium
b. Heart rate: 250 to 350 beats/min
c. More than one P wave precedes QRS complex
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Can range from 1 to 8
d. P wave appears as saw-toothed spikes between QRS complexes
e. QRS complexes are normal
f. T wave usually lost in P waves
2. Clinical significance
a. Rarely occurs in healthy individuals
b. Found in patients with underlying heart disease
c. Can occur in patients with
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Mitral valve disease
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Coronary artery disease
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Acute myocardial infarction
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Chronic lung disease
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Hypertensive heart disease
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Pulmonary emboli
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Patients who have undergone cardiac surgery
Atrial Fibrillation
1. Description
a. P waves have no definite pattern or shape
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Appear as irregular, wavy undulations between QRS complexes
b. QRS complexes are normal, but do not have a definite pattern
c. Atria contract 400 to 500 times per minute
d. Ventricular rate may be normal or rapid (150 to 180 beats/min)
2. Clinical significance
a. Common dysrhythmia that occurs in healthy individuals
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Caused by stress, excessive alcohol consumption, vomiting
b. Can occur in patients with heart disease
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Individuals younger than 50 years: may be caused by
- Congenital heart disease
- Rheumatic heart disease with mitral valve involvement
Individuals older than 50 years: may be caused by
- Coronary artery disease
- Mitral valve disease
- Hypertension heart disease
Premature Ventricular Contraction (PVC)
1. Description
a. Most common rhythm disturbance seen on ECG
b. Beat comes early in the cycle
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Not preceded by a P wave
c. Wide and distorted QRS complex
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Easily stands out on ECG
d. T wave opposite in direction to R wave
e. Baseline distance after PVC: usually longer than normal
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Means PVC is followed by a pause before next normal beat
2. Clinical significance
a. Seen in normal individuals in all age groups
b. Caused by
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Anxiety
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Smoking
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Caffeine
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Alcohol
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Certain medications (e.g., epinephrine)
c. Also can occur with any type of heart disease
d. Seen most often with
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Hypertensive heart disease
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Ischemic heart disease
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Lung disease with hypoxia
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Digitalis toxicity
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Mitral valve prolapse
Ventricular Tachycardia
1. Description
a. Series of three or more consecutive PVCs
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Occur at a rate of 150 to 250 beats/min
b. May occur suddenly and last for a short time
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Or may last for a long time
c. QRS complexes are bizarre and widened
d. No P waves present
e. Sustained VT: life-threatening
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Prevents adequate filling time for heart
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May degenerate into ventricular fibrillation and cardiac arrest
2. Clinical significance
a. Usually seen in patients with acute or chronic heart disease
b. Runs of VT indicate coronary artery disease
c. Also occurs as a complication of myocardial infarction
Ventricular Fibrillation (V-fib)
1. Description
a. Most serious dysrhythmia
b. Ventricles do not beat in a coordinated manner
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Instead they twitch or fibrillate
c. Virtually no blood is ejected into systemic circulation
d. Appears as irregular, chaotic undulations of baseline
e. No recognizable P waves, QRS complexes, or T waves
f. No effective ventricular pumping action
g. Must be treated STAT
h. Can lead to sudden death
2. Clinical significance
a. Most common cause: acute myocardial infarction
b. Also can occur in patients with
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Organic heart disease
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Cardiac dysrhythmias
c. May be preceded by PVCs or ventricular tachycardia, or may occur spontaneously
Pulmonary Function Tests
1. Purpose of PFT:
2. Assists in
3. PFT tests include
a. Spirometry
b. Lung volumes
c. Diffusion capacity
d. Arterial blood gas studies
e. Pulse oximetry
f. Cardiopulmonary exercise tests
Spirometry
1. Noninvasive screening test often performed in the medical office
2. Spirometer:
a. Measures
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b. Report printed out as a table and graph
3. Considered a screening test
a. Abnormal results require:
- Additional PFT tests
- Possibly a CT scan
4. Indications for performing spirometry
a.
b.
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Smoking
Exposure to environmental pollutants
- Coal dust
- Asbestos
- Exhaust fumes
c.
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Asthma
Chronic bronchitis
Emphysema
d.
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To assess probable lung performance during an operation
e.
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For a compensation program (e.g., coal miner)
Spirometry Test Results
1. Spirometry: provides numerous measurements to assess lung function
2. Forced vital capacity (FVC): maximal volume of air that can be expired when patient
exhales as forcefully and rapidly as possible for as long as possible (measured in liters)
a. FVC breathing maneuver
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Patient takes a deep breath until lungs are completely full
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Patient blows all air out of lungs into a mouthpiece
- As hard and fast as possible
- Until no more air can be expelled
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To be considered an adequate test
- Patient must forcibly blow out all air and continue smooth, continuous
exhaling for 6 seconds
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Minimum of three acceptable efforts must be obtained
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Some patients have trouble performing breathing maneuver due to:
- Physical impairment
- Poor motivation
- Do not understand instructions
• Be patient and work with patient to help perform the maneuver
• If unable to perform the maneuver after eight attempts: discontinue testing
- Fatigue may affect accuracy of results
3. Forced expiratory volume after 1 second (FEV1): volume of air that is forcefully exhaled
during first second of the FVC breathing maneuver
a. Automatically determined by the spirometer
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From FVC maneuver
4. FEV1/FVC ratio: comparison of FEV1 with FVC
a. Patient with healthy lungs: 70% to 75% of air (FVC) is exhaled
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In the first second (FEV1) of breathing maneuver (expressed as a percentage)
- Example: patient with healthy lungs may have a ratio of 85%
- Means that 85% of exhaled air was exhaled during the first second
of the breathing maneuver
b. Patients with COPD: ratio is less than 70% to 75%
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Patient unable to move exhaled air out of lungs during first second
- Because of an obstruction to the airflow
- Examples: inflammation, damaged lung tissue
c. Categories of airflow obstruction
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Mild obstruction: 61% to 69%
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Moderate obstruction: 45% to 60%
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Severe obstruction: less than 45%
5. Evaluation of results
a. Demographic factors used to evaluate results entered into the machine
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Age
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Sex
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Weight
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Height
b. Based on demographic factors: spirometer automatically calculates predicted values
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Predicted value: what the results should be for a patient with healthy lungs
c. When test is run: physician compares measured values with predicted values
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Values are printed out on the spirometry report
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Assists physician in detecting pulmonary disease
6. Patient preparation
a. Do not eat a heavy meal for 8 hours before test
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Full stomach: interferes with performing breathing maneuver
b. Stop smoking at least 8 hours before test
c. Do not take bronchodilators 4 hours before test
d. Do not engage in strenuous activity 4 hours before test
e. Wear loose, nonrestrictive clothing: keeps chest area free
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Easier to perform breathing maneuver
Peak Flow Measurement
Asthma
1.
a. Affects
2. Trachea divides
a. After primary bronchi enter lungs
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Branch into smaller bronchi (secondary and tertiary bronchi)
- Then into smaller passages:
b. Bronchioles continue to branch
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Finally lead into microscopic
- Terminate in clusters of tiny air sacs:
3. Asthma affects
4. Can occur at any age (but more common in children and young adults)
a. Affects:
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Boys more frequently before puberty
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Girls more frequently after puberty
5. Characteristics of asthma:
a.
b. Recurrent attacks of:
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- Wheezing:
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c. Asthma attack usually followed by a symptom-free period
d. Can be controlled by:
Recognizing warning signs and symptoms of an attack
Treating symptoms when they first occur
e. Failure to treat asthma
Can lead to serious complications
- Example: Permanent lung damage
f. Cause of asthma: not known
Thought to be caused by:
- Genetics
- Certain childhood respiratory infections
- Contact with allergens
- Exposure to certain viral infections in infancy or early childhood.
Peak Flow Meter
1.
2. Used to
3. Manual peak flow meter
4. Digital peak flow meter
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5. Available in two ranges:
a. Low range
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Ranges from 0 to 300
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Used by young children and some older patients
b. Full range
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Ranges from 0 to 800
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Used by older children, teenagers, and adults
•
Adult has much larger bronchial tubes than a child
- Needs the wider range
Purpose of Peak Flow Measurements
1. Used to monitor
a.
1.
•
To determine how well asthma is being controlled
High number
1.
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Low number
•
- Results in a decrease in oxygen available to the body
4. Use of peak flow measurements:
a. Monitor how
• Assists physician in knowing what medications to prescribe
b.
5. Recognize early
1. Determine the
1.
a.
•
Can sometimes identify asthma triggers by measuring PFR
Before and after exposure to a trigger suspected of causing the asthma
Content Outline
Copyright © 2012, 2008, 2004, 2000, 1995, 1990, 1984, 1979 by Saunders, an imprint of Elsevier Inc.
Copyright © 2012, 2008, 2004, 2000, 1995, 1990, 1984, 1979 by Saunders, an imprint of Elsevier Inc.