Determinants and Assessment of Pulmonary Function Flashcards
What does the surfactant layer consist of and what does it do?
Type 2 cells secrete surfactant which is a lipoprotein that lines the inner wall of alveoli, reducing surface tension to precent alveolar collapse. SURFACTANT KEEPS ALVEOLI OPEN
What is anaerobic metabolism?
The making of energy (glucose) in an environment absent of O2
What happens to our muscles when anaerobic metabolism occurs?
Our muscles get sore because there is not enough air which leads to lactic acid build up
Define Ventillation
It is the actual work of breathing and movement of air from outside to inside the lung tissues. (the amount go gas reaching alveoli)
Define Diffusion
Exchange of gases at the alveolar membrane
Define Perfusion
Pumping of blood to organs and tissues, systemic and pulmonary systems. (the blood flow in pulmonary capillaries)
What are the 3 determinants of O2 status?
PaO2, SaO2, Hemoglobin
What is PAO2
partial pressure of oxygen in alveoli
normal range 100-105 mmHg
What is PaO2
partial pressure of O2 dissolved in arterial blood
normal range 75-100 mmHg
What is PvO2
partial pressure of O2 dissolved in venous blood
normal range 40 mmHg
What is tidal volume
amount of air that moves in and out of lungs with each normal breath
What is vital capacity
maximum amount of air expired after a maximal inspiration
What is SaO2
O2 saturation; the measure of the % of O2 combined with hemoglobin
Why is SaO2 important
degree of saturation is important in determining amount of O2 available for delivery to tissues
What is hemoglobin
major carrier of O2 in blood and an important factor in tissue oxygenation - composed of protein and heme and a major component of RBC
What is the normal range for hemoglobin?
females 12-15 g/dL
males 13.5-17 g/dL
What does abnormally low hemoglobin indicate?
that tissue perfusion is also low
In the oxyhemoglobin dissociation curve what is a left shift?
- alkalosis; increase pH, decrease PaCO2 (hypocapnia)
- increased affinity to hmg in O2; in lungs hmg binds to O2
- at tissues hmg does not readily release O2
- ABG increased SaO2, O2 sat increased, increased SvO2
In the oxyhemoglobin dissociation curve what is a right shift?
- acidosis; decrease pH, increased PaCo2 (hypercapnia)
- decreased affinity of hmg for O2; in lungs hmg does not easily bind with O2
- at tissues hmg readily releases O2
- ABG decreased SaO2, decreased SpO2, decreased SvO2
Pulmonary Vascular Resistance
measures the resistance to blood flow in pulmonary vascular system, a low-resistance system
What 3 main factors determine pulmonary resistance
length of vessels
radius of vessels
viscosity
Cor Pulmonae
R ventricular hypertrophy and dilation secondary to pulmonary disease - is a complication of both restrictive and obstructive pulmonary diseases
Oxygenation occurs as a result of what 3 processes
O2 intake
O2 delivery
use of O2 for metabolic processes
what is the VQ ratio
ventilation (v) must match perfusion (Q)
What happens when VQ ratio is mismatched
impaired gas exchange
Why is nutritional history important when assessing respiratory system
malnutrition can contribute to developing respiratory failure
where do you hear vesicular sounds on auscultation
peripheral fields
where do you hear bronchial sounds on auscultation
trachea and larynx
where do you hear bronchovesicular sounds on auscultation
all lobes near major airways
What is orthopnea
state in which pt assumes a head up position to relieve dyspnea
Difference between cardiogenic pain and pleuritic chest pain
Cardiogenic pain is unaffected by breathing, pleuritic pain is sharp pains on inhalation
What is capnography
noninvasive measurement of CO2 concentration in expired gases
Arterial Blood Gases
provide valuable information on pts acid-base and oxygenation status
Kidney function
is a slow but powerful response
Lung function
is a rapid but limited response
normal pH
7.35-7.45
normal PaCO2
35-45
normal HCO3
24-28
normal PaO2
80-100
normal SaO2
greater than 95%
Compensation occurs when
another value is outside its normal range
No compensation occurs when
other value is within normal range
buffer systems prevent
major changes in H+
in respiratory/metabolic acidosis increased ____ is attempt to get rid of _____
respiration; CO2
in respiratory/metabolic alkalosis decreased ___ is to retain _____
respirations; CO2
kidneys regulate ____ level in ECF
HCO3-
in respiratory/metabolic acidosis the kidneys
excrete hydrogen ions and conserve HCO3 to restore balance
in respiratory/metabolic alkalosis the kidneys
retain hydrogen ions and excrete HCO3 ions to restore balance
uncompensated =
abnormal pH with one abnormal value and one normal value
partially compensated =
abnormal pH with 2 abnormal values
compensated (chronic) =
normal pH with 2 abnormal values
corrected =
normal pH and 2 normal values. No acid-base disturbance currently exists
common causes of acute respiratory acidosis
respiratory depression, decreased ventilation, altered diffusion/ventilation/perfusion mismatch
restrictive pulmonary disease =
reduced total lung capacity
obstructive pulmonary disease
air moves in and out at reduced rate
pneumonia arises from
micro-aspiration of colonized organisms in the upper airway
pneumonia infection results in
pulmonary inflammation -> congestion
red hepatization of pneumonia
blood vessels and capillaries dilate and fill with exudate and organisms
grey hepatization of pneumonia
blood flow decreases and leukocytes and fibrin consolidate
resolution of pneumonia
exudate becomes lysed and macrophages clean up
consolidation in grey hepatization means
worsening, not a bad things but shown progression
signs and symptoms of pneumonia
cough, fever, pleuritic chest pain, weight loss, muscle aches and pains, fatigue, decreased air entry, hemoptysis, night sweats, crackles/congestion on auscultation
goals in pneumonia pt
improve gas exchange and improve airway patency
clinical manifestations of restrictive pulmonary disorders
increased resp rate, decrease tidal volume, SOB, cough, chest pain/discomfort, fatigue, history of weight loss
types of COPD
emphysema, chronic bronchitis, cystic fibrosis, asthma
pathophysiology of obstructive disorders (COPD)
air is able to flow into lungs but then becomes trapped, difficult to exhale so air moves in and out at a decreased rate
respiratory insufficiency
maintains oxygenation, acid base imbalance persists, normal pH + increased PaCO2 and increased HCO3 = compensated respiratory acidosis
- live with impeding respiratory failure
COPD is characterized by
exacerbations caused by triggers
clinical features of obstructive pulmonary disorders (COPD)
bronchospasm, bronchoconstriction, airway obstruction
physical findings of obstructive pulmonary disorders (COPD)
diminished breath sounds (often related to pneumonia), increased accessory muscle use, rhonchi, wheezes, prolonged expiration, increased sputum production, pursed lip breathing, cough, crackles not cleared by coughing and deep breathing
COPD treatment is aimed at
(1) improving airway obstruction
(2) providing relief of symptoms
(3) modifying or preventing exacerbations
(4) altering disease progression
using O2 therapy in pts with COPD increases risk for
hypoxemia
pharmacotherapy for pulmonary disorders
beta 2 agonsits, anti cholinergic bronchodilators, corticosteroids, mucolytics, pulmonary vasodilators
NPPV is
noninvasive positive pressure ventilation
what is NPPV for
reduces intubation, used in exacerbations and ICU setting
BREATH AIR acronym
Bronchospasm
Rales
Effusions
Airway obstruction
Thick secretions
Hemoglobin (low)
Anxiety
Interpersonal issues
Religious concerns
external respiration
bulk flow of air into and out of the lungs
internal respiration
capillary gas exchange in body tissues
alveolar gas exchange
- surface area
- partial pressure gradient of gases
- matching of ventilation and perfusion
in emphysema alveoli are ____________, surface area is _______, and ________ _________
gradually reduced; reduced; diffusion decreases
gas exchange in lungs happens at the
alveoli-capillary membrane
alveoli-capillary membrane has a large surface area for
efficient gas exchange
ARDS is
acute respiratory distress syndrome aka acute lung injury
pathophysiology of ARDS
widespread damage to alveolar capillary membrane causes widespread inflammatory event, can be fatal
acute respiratory failure
cardiopulmonary system fails to maintain gas exchange
- oxygenation failure and ventilation failure
ARDS can affect all organs because of
hypoxemia
if ARDS is accompanied by decreased CO2 it can lead to
hypoperfusion and shock
ventilatory failure can result in
hypercapnia and respiratory acidosis
ARDS can be ____ stage of someone with COPD and/or penumonia
end stage
clinical manifestations of pt in respiratory failure
cyanotic, pallor, high resps, breath sounds diminished, high BP, high pulse, increased temp (due to infection), CXR would show consolidation
acute respiratory failure =
oxygenation failure
in acute respiratory failure PO2 is less than
60
CO2 can diffuse ____ times faster than O2
20 times
acute respiratory failure causes
acute respiratory acidosis, alveolar hypoventilation, build up of CO2
complications of respiratory failure
oxygenation failure and ventilation failure
oxygenation failure
organ hypoxia, hypoperfusion/hypoxic organ
ventilation failure
severe hypercapnia, severe respiratory acidosis
pulmonary embolism
large thrombi obstructs perfusion in the pt artery or its branches
small PE
may be asymptomatic
large PE
lodge in main pulmonary artery - severe, immediate symptoms
may have several ____________ cause obstruction of multiple tiny pulmonary vessels
micro-emboli
blockage in pulmonary artery causes
increased pulmonary pressure, increased resistance to blood flow in right ventricle = increased R ventricle workload and decreased lung perfusion
if R ventricle cannot pump against the pressure
right heart failure occurs
inflammatory response is
increased neutrophils and increased platelet activating factors (clots)
manifestations of pulmonary embolism
hypotension, hypoxemia, SOB, dyspnea, wheezing, pleuritic pain, orthopnea
common outcome of pulmonary embolism
impaired gas exchange
___% of those with a PE have pre-existing confirmed DVT
44%
types of emboli
thromboembolism, fat embolism, amniotic, venous air embolism
thromboembolism
fat embolism
amniotic
venous air embolism
more than 80% if PE originates as DVT in the ___ ______
lower extremities
management of PE includes
anticoagulant therapy, vena cava filter, thromboembolytic therapy, embolectomy
ABGs for PE would look like
low PaO2 and low PCO2 because no exchange of CO2 and/or O2 happens
catheter directed thrombolysis
thrombolytic agent is administered directly into the pulmonary artery via a pulmonary artery catheter, the usual thrombolytic agent is full dose heparin
