Respiratory Assessment and OSA Key Points Flashcards
Primary Purpose of Resp System
gas exchange
Gas exchange
involves the transfer
of oxygen and carbon dioxide between the atmosphere and the blood
Upper Resp Tract
nose, mouth, pharynx, adenoids, tonsils, epiglottis,
larynx, and trachea
Nose
warms, cleanses, and humidifies air before it enters lungs
Voice
Vibrational sounds originating in the larynx lead to vocalization
Anatomical Dead Space
The trachea, bronchi, and bronchioles are passages that conduct air to the alveoli. These passages are called anatomic dead space because the air is not involved in gas exchange.
Lower Resp Tract
The lower respiratory tract consists of the bronchi, bronchioles, alveolar ducts, and alveoli.
Gas Exchange Diffusion
Across the alveolar-capillary membrane
Surfactant
lipoprotein that helps to keep the alveoli open, thus preventing alveolar collapse
Decreased Intrathoracic Pressure
Contraction of the diaphragm results in decreased intrathoracic pressure, allowing air to enter the lungs.
Diaphragm
Major muscle of respiration
Oxygenation
involves the delivery of oxygen from the atmospheric air to alveolar capillaries and eventual diffusion into the alveoli.
Ventilation
involves inspiration and expiration
Inspiration
Movement of air into the lungs
Active process
Involves muscle contraction
Expiration
Movement of air out of the lungs
Passive process
Labored Expiration
When recoil is reduced, the expiration becomes more active
Tidal Volume
Volume of air exchanged with each breath
Adults Normal VT
500 mL
Compliance
The ability of the lungs to expand
With decreased compliance, it is harder for the lungs to inflate
Resistance Increase
When resistance increases, there is often some type of impairment to air flow into the lungs, such as narrowed airways or presence of secretions.
Arterial Blood Gases (ABGs)
Measured to assess oxygenation, ventilation, and acid-base balance status
ABG Analysis
Includes measurement of the partial pressure of O2 in arterial blood, arterial pressure of carbon dioxide, acidity, bicarbonate, and arterial oxygen saturation in the arterial blood.
Arterial Blood
PaO2
Arterial Pressure of Carbon Dioxide
PaCO2
Acidity
pH
Bicarbonate
HCO3-
Arterial Oxygen Saturation
SaO2
Pulse Oximetry Probe
Monitors arterial oxygen saturation continuously
Applied to finger, toe, ear, or bridge of the nose
Transcutaneous Carbon Dioxide
PtCO2
End-tidal CO2
PetCO2
CO2 Monitoring
PtCO2 and PetCO2 capnography
Capnography
Transcutaneous measurement of CO2 capnography is a noninvasive method of estimating PaCO2. It is presented as a graph of expiratory CO2 plotted against time.
Medulla in Brainstem
Respiratory center
Responds to chemical and mechanical signals from the body
Chemoreceptor
a receptor that responds to a change in the chemical composition (PaCO2 and pH) of the fluid around it
Mechanical Receptor
are stimulated by a variety of physiologic factors, such as irritants, muscle stretching, and alveolar wall distortion
Respiratory Defense Mechanism
include filtration of air, mucociliary clearance system, cough reflex, reflex bronchoconstriction, and alveolar macrophages
Age-Related Changes
Changes in structure, defense mechanisms, and respiratory control
Variability
There is much variability in the extent of these changes in persons of the same age. The older adult patient who has a significant smoking history, is obese, and has a chronic illness is at greatest risk of adverse outcomes
Assessment of Resp System
Use judgment to decide whether all or part of the history and physical assessment will be completed, based on your immediate evaluation of the patient and the degree of respiratory distress
Respiratory Distress
If respiratory distress is severe, only obtain pertinent information and defer a thorough assessment until the medical management is started and the patient’s condition stabilizes
Health History
consists of the health history, medications, surgery or other treatments, family health history, psychosocial history, and a review of systems using functional health patterns
Respiratory Problems
Explore and document common signs of respiratory problems (e.g., cough, dyspnea). Describe the course of the patient’s illness, including when it began, the type of symptoms, and factors that relieve or worsen symptoms.
Cough
Evaluate a cough by the quality of the cough and presence or absence of sputum.
Vital Signs
Obtain vital signs prior to the physical assessment. Assess the nose, mouth, pharynx, neck, thorax, and lungs and observe the respiratory rate, depth, and rhythm.
Air Entry
Adequate, slightly decreased, decreased, or absent
3 Normal Breath Sounds
Presence of Absence
Vesicular, bronchovesicular, and bronchial
Adventitious Sounds
Determine the presence of abnormal sounds including fine crackles, coarse crackles, wheezes, strider, and pleural friction rub
Oximetry
measurement of the blood’s O2 saturation. It can be measured in both arterial and venous blood. There are noninvasive and invasive means to measure both
Classic Diagnostic Tests
SpO2 monitoring and ABG analysis are classic diagnostic tests used to evaluate the respiratory system
SpO2 issues
Accurate SpO2 measurements may be hard to obtain on patients who are hypothermic, receiving IV vasopressor therapy, or have hypoperfusion and vasoconstriction
Catheters
Both CVP and PA catheters can include sensors to measure oxygen saturation of hemoglobin in venous blood termed central venous oxygen saturation (ScvO2) and SvO2
Balance of oxygenation
SvO2 and ScvO2 reflect the balance among oxygenation of the arterial blood, tissue perfusion, and tissue O2 consumption
Sustained decreases
may indicate decreased arterial oxygenation, low CO, low hemoglobin level, or increased O2 consumption or extraction
CO2 Monitoring
using transcutaneous CO2 (PtCO2) and end-tidal CO2 (PetCO2) capnography
Chest X-Ray
most common test for assessing the respiratory system, as well as the progression of disease and response to treatment
Sputum Studies
examined to identify infecting organisms or help confirm a diagnosis
Skin Tests
test for allergic reactions or exposure to tuberculosis or fungi
Bronchoscopy
a procedure in which the bronchi are visualized through a fiberoptic tube. It may be used for diagnostic purposes, to obtain biopsy specimens, and assess changes resulting from treatment
Thoracentesis
the insertion of a large bore needle through the chest wall into the pleural space to obtain specimens for diagnostic evaluation, remove pleural fluid, or instill medication into the pleural space
Pulmonary Function Tests
PFTs
Measure lung volumes and airflow
PFT Results
can diagnose pulmonary disease, monitor disease progression, evaluate disability, and evaluate response to bronchodilators
Acute PFT
In the acute setting, more specific PFT parameters are used to determine the ability to wean and extubate from mechanical ventilation
Ecercise Testing
used in diagnosis, measuring functional capacity and response to treatment, and determining level of activity tolerance
Sleep-Disordered Breathing
SDB
Abnormal respiratory patterns associated with sleep
Obstructive Sleep Apnea
OSA
The most commonly diagnosed sleep-disordered breathing problem
Clinical Manifestations of OSA
partial or complete upper airway obstruction during sleep, frequent arousals during sleep, insomnia, excessive daytime sleepiness, snoring, and witnessed apneic episodes
Mild Sleep Apnea
May respond to simple measures like changing sleeping positions
Continuous Positive Airway Pressure
CPAP
For patients with severe sleep apnea
By mask
Treatment of choice
OSA Hospitalization
be aware that the use of opioid analgesics and sedating medications may worsen OSA symptoms by depressing respiration. Patients should continue CPAP use in the hospital
