Oxygenation Flashcards
1
Q
Blood is oxygenated through which mechanisms?
A
- Ventilation
- Perfusion
- Transport of respiratory gases
2
Q
What controls the rate and depth of respiration in response to changing tissue oxygen demands?
A
- neural regulators
- chemical regulators
3
Q
Which system provides the the transport mechanism to distribute oxygen to cells and tissues of the body?
A
cardiovascular system
4
Q
Where does the exchange of respiratory gases occur?
A
between the environment and the blood
5
Q
What is respiration?
A
the exchange of oxygen and carbon dioxide during cellular metabolism
6
Q
What are the three steps in the process of oxygenation?
A
- Ventilation
- Perfusion
- Diffusion
7
Q
What moves gases into and out of the lungs?
A
pressure changes
8
Q
What causes air to flow into the lungs?
A
Intrapleural pressure becomes more negative, setting up a pressure gradient between the atmosphere and the alveoli.
9
Q
Which muscles are used for inspiration?
A
- diaphragm
- intercostal muscles
note: these muscles contract to create a negative pleural pressure and increase the size of the thorax for inspiration.
10
Q
What is the process of moving gases into and out of the lungs?
A
Ventilation
11
Q
What is the major inspiratory muscle of respiration?
A
diaphragm
12
Q
Which nerve innervates the diaphragm?
A
phrenic nerve
note: exists in the spinal cord at the fourth cervical vertebra.
13
Q
What is the term that relates to the ability of the cardiovascular system to pump oxygenated blood to the tissues and return deoxygenated blood to the lungs?
A
Perfusion
14
Q
How is inspiration stimulated?
A
Chemical receptors in the aorta
15
Q
What is the chemical produced in the lungs to maintain the surface tension of the alveoli and keep them from collapsing?
A
Surfactant
16
Q
What is the collapse of alveoli that prevents normal exchange of oxygen and carbon dioxide?
A
Atelectasis
17
Q
Which observation of a patient’s breathing can indicate ventilatory fatigue, air hunger, or decreased lung expansion?
A
elevation of the patient’s clavicles during inspiration
18
Q
What is the term for the ability of the lungs to distend or expand in response to increased intraalveolar pressure?
A
Compliance
19
Q
How do diseases such as pulmonary edema, insterstitial and pleural fibrosis, and congenital or traumatic structural abnormalities such as kyphosis or fractured ribs effect respiratory compliance?
A
decreases compliance
20
Q
What is the term for the increase in pressure that occurs as the diameter of the airway decreases from mouth/nose to alveoli?
A
Airway Resistance
21
Q
What is tidal volume?
A
the amount of air exhaled after normal inspiration
22
Q
What is residual volume?
A
the amount of air left in the alveoli after a full expiration
23
Q
What is forced vital capacity?
A
the maximum amount of air that can be removed from the lungs during forced expiration.
24
Q
What is the process for exchange of respiratory gases in the alveoli and the capillaries?
A
Diffusion
25
How does the thickness of the alveolar capillary membrane effect diffusion?
increased thickness impedes diffusion.
26
What are the three factors that influence the capacity of the blood to carry oxygen?
1. The amount of dissolved oxygen in the plasma
2. The amount of hemoglobin
3. The tendency of hemoglobin to bind with oxygen
27
Which physiological process produces CO2
cellular metabolism
28
Which characteristics of respiration does the CNS control?
respiratory rate, depth, and rhythm
29
Which characteristics of respiration does the cerebral cortex regulate?
voluntary control of respiration (delivers impulse to the respiratory motor neurons by way of the spinal cord)
30
Which characteristics of respiration is controlled by chemicals?
rate and depth: changes in CO2, O2, H ions (pH)
stimulate the chemoreceptors located in the medulla, aortic body, and carotid body, which in turn stimulate neural regulators to adjust rate & depth.
31
What is stroke volume?
the volume of blood ejected from the ventricles during systole
32
How does hemorrhage and dehydration effect stroke volume?
decrease in volume = decrease in stroke volume
33
What is the Frank-Starling (Starling's) law of the heart?
As the myocardium stretches, the strength of the subsequent contractions increases
34
What happens when the myocardium is stretched beyond the physiological limits of the heart?
Results in insufficient stroke volume
35
What does an insufficient stroke volume lead to?
back up in the pulmonary (left heart failure) or systemic (right heart failure) circulation
36
What is cardiac output?
the amount of blood ejected from the left ventricle
37
What is the normal CO in a healthy adult at rest?
4-6L/min
38
What is the term for the amount of blood in the left ventricle at the end of diastole?
Preload
39
What is the term for the resistance to left ventricular ejection?
Afterload
40
Which part of the Autonomic nervous system increases the rate of impulse generation and speed of transmission?
sympathetic
41
Which part of the Autonomic nervious system decreases the rate of impulse generation and speed of transmission?
parasympathetic
42
Where does the conduction system of the heart originate?
SA node
43
What are four factors that influence adequacy of circulation, ventilation, perfusion, and transport of respiratory gasses to the tissues?
1. Physiological
2. Developmental
3. Lifestyle
4. Environmental
44
How does anemia and inhalation of toxic chemicals effect respiratory function?
Decreases the oxygen-carrying capacity of blood by reducing the amount of available hemoglobin to transport oxygen.
45
What is the physiological response to hypoxemia?
The development of increased red blood cells (polycythemia)
46
What is the most common toxic inhalant that decreases the oxygen-carrying capacity of blood?
Carbon monoxide
47
how does CO toxicity effect oxygen carrying capacity?
Hemoglobin strongly binds with CO, creating a functional anemia.
48
What is the term for abnormally low circulating blood volume?
hypovolemia
49
How does the body adapt to significant fluid loss?
- peripheral vasoconstriction
- increased HR
- increased CO
50
What is FiO2?
fraction of inspired oxygen
51
What causes decreases in FiO2?
upper and lower airway obstruction, or hypoventilation
52
How does increased metabolic activity effect oxygen demand?
increases oxygen demand
53
How does the body adapt to increases in CO2?
increases rate and depth of respiration
54
Which patients are at a greater risk for hypoxemia?
patients with pulmonary diseases
55
What are the three primary alterations in respiratory functioning?
1. hypoventilation
2. hyperventilation
3. hypoxia
56
What is the normal arterial CO2 tension (PaCO2) range?
35-45 mmHg
57
What is the normal arterial O2 tension (PaO2) range?
80-100 mmHg
58
What is the normal SpO2?
greater than or equal to 95%
59
What happens when alveolar ventilation is inadequate to meet the oxygen demand of the body or eliminate sufficient carbon dioxide?
Hypoventilation
60
What is the maximum 02 administration for a patient with COPD?
24% to 28% (1-3L/min)
61
What does excessive retention of carbon dioxide lead to?
respiratory acidosis and respiratory arrest
62
What are the initial symptoms of hypoventilation?
- mental status changes
- dysrhythmias
- potential cardiac arrest
63
What happens if hypoventilation is left untreated?
- status rapidly declines
- convulsions
- unconsciousness
- death
64
What is the state of ventilation in which the lungs remove carbon dioxide faster than it is produced by cellular metabolism?
Hyperventilation
65
Which 4 conditions induce hyperventilation?
- severe anxiety
- infection
- drugs
- acid/base imbalance
66
What does excessive ventilation of carbon dioxide lead to?
respiratory alkalosis
67
What are signs and symptoms of hyperventilation?
- rapid respirations
- sighing breaths
- numbness and tingling of hands/feet
- lightheadedness
- loss of consciousness
68
What is the term for inadequate tissue oxygenation at the cellular level?
Hypoxia
69
What are 6 possible causes of hypoxia?
- decreased hemoglobin
- diminished concentration of inspired oxygen
- inability of the tissues to extract oxygen from blood
- decreased diffusion of O2 from alveoli to the blood
- poor tissue perfusion with oxygenated blood
- impaired ventilation
70
What are the clinical signs and symptoms of hypoxia?
- apprehension
- restlessness
- inability to concentrate
- decreased LOC
- dizziness
- behavioral changes
71
How are vital signs affected by hypoxia?
- increased pulse rate
| - increased rate/depth of respiration
72
What causes cyanosis?
presence of desaturated hemoglobin in capillaries
73
How does a nurse assess hypoxia via cyanosis?
central cyanosis as observed in the tongue, soft palate, and conjunctiva of the eye where blood flow is high
74
What does peripheral cyanosis indicate?
often result of vasoconstriction and stagnant blood flow
75
What is the term for a deviation from the normal sinus rhythm caused by electrical impulses that do not originate from the SA node?
dysrhythmias
76
How are disrhythmias classified?
By cardiac response and site of impulse origin.
77
What makes atrial fibrillation irregular?
multiple pacemaker cites and the unpredictable conduction to the ventricles
78
What are abnormal impulses originating above the ventricles called?
supraventricular dysrhythmias
79
What is the sudden, rapid onset of tachycardia originating from above the AV node called?
Paroxysmal supraventricular tachycardia
80
What are the disrhythmias caused by an ectopic site of impulse formation within the ventricles called?(2)
- Ventricular tachycardia
| - Ventricular fibrillation
81
Why is ventricular tachycardia life-threatening?
decreased CO and the potential to deteriorate into ventricular fibrillation or sudden cardiac death
82
What are clinical findings of left-sided heart failure?
- crackles at base of lungs
- hypoxia
- dyspnea during exertion
- cough
- paroxysmal nocturnal dyspnea
83
What are clinical findings of right-sided heart failure?
- weight gain
- distended neck veins
- hepatomegaly and splenomegaly
- dependent peripheral edema
84
What are the two types of impaired valvular function?
- stenosis (hardening)
| - regurgitation (impaired closure)
85
What are two common outcomes of myocardial ischemia?
- angina pectoris
| - MI
86
Why are infants and toddlers at risk for upper respiratory tract infections?
- frequent exposure to other children
- immature immune system
- exposure to secondhand smoke
87
What are the 4 characteristics of chest pain that a nurse needs to assess for?
- location
- duration
- radiation
- frequency
88
What is the term for an abnormal condition in which a person must sit or stand to breathe comfortably?
orthopnea
89
What is hemoptysis?
blood sputum
90
What are characteristics of abnormal sputum?
- green
- bloody (hemoptysis)
- think/thin
- foul odor
- increased/decreased
91
If hemoptysis is present, where are likely sources of blood?
- upper respiratory tract
- sinus drainage
- GI tract (hematemesis)
92
How can pH testing help to determine the source of bloody sputum?
blood from upper respiratory/sinus will have alkaline pH, blood from GI will be acidic.
93
What are the most common sources of environmental exposure in the home?
- cigarette smoke
- CO
- radon
94
What do clubbed nails often indicate?
- prolonged oxygen deficiency
- endocarditis
- congenital heart defects
95
what is the term for the when the chest wall contracts during inspiration and expands during exhalation?
paradoxical breathing (asynchronous breathing)
96
What is the term for an increased rate and depth of respirations?
Kussmaul respiration
97
What is the term for the absence of respirations for a period of time?
apnea
98
What is the term for when the respiratory pattern has periods of apnea followed by periods of deep breathing and then shallow breathing followed by more apnea?
Cheyne-Stokes respiration
99
What causes Cheyne-Stokes respiration?
decreased blood floow or injury to the brainstem
100
What is the cause of xanthelasma (yellow lesions on the eyelids)?
hyperlipidemia
101
What is the cause of corneal arcus (whitish opaque ring around junction of cornea and sclera)?
Abnormal finding in young to middle-age adults with hyperlipidemia (normal finding in older adults with arcus senilis)
102
What is the cause of pale conjunctivae?
anemia
103
What is the cause of cyanotic conjunctivae?
hypoxemia
104
What is the cause of petechiae on conjunctivae?
fat embolus or bacterial endocarditis
105
What is the cause of cyanotic mucous membranes?
hypoxia
106
What is the cause of pursed-lip breathing
associated with chronic lung disease
107
What is the cause of neck vein distention?
associated with right-sided heart failure
108
What is the cause of flaring nares?
air hunger, dyspnea
109
What is the cause of chest retractions?
increased WOB, dyspnea
110
What is the cause of chest asymmetry?
chest wall injury
111
What is the cause of peripheral cyanosis?
vasoconstriction and diminished blood flow
112
What is the cause of central cyanosis?
hypoxemia
113
What is the cause of decreased skin turgor?
dehydration (normal in older adults d/t decreased skin elasticity)
114
What is the cause of dependent edema?
associated with right and left-sided heart failure
115
What is the cause of periorbital edema?
associated with kidney disease
116
What is the cause of cyanosis in the fingertips and nail beds?
decreased CO or hypoxia
117
What is the cause of splinter hemorrhages in the nail beds?
bacterial endocarditis
118
Why are cardiac enzymes tested?
To diagnose acute myocardial infarcts
119
What is the normal range for the cardiac enzyme creatinine kinase (CK)?
male: 55-170 units/L
female: 30-135 units/L
120
Why are cardiac troponins tested?
value elevates as early as 3 hours after myocardial injury. Value for cardiac troponin I often remains elevated for 7-10 days; value for cardiac troponin T for 10-14 days
121
What is the normal range for cardiac troponin I?
<0.03 ng/mL
122
What is the normal range for cardiac troponin T?
<0.1 ng/mL
123
Why is myoglobin tested?
Early index of damage to myocardium in myocardial infarction or reinfarction. increases within 3 hours.
124
What is the normal range for myoglobin?
<90mcg/L
125
What is the normal range for serum potassium?
3.5-5 mEq/L
126
Patients taking ACE inhibitors are at risk for an increase in which electrolyte?
potassium (hyperkalemia)
127
What is the normal range for fasting cholesterol?
<200mg/dL
128
What is the normal range for LDLs?
<130
129
What is the normal range VLDLs (very low density lipoproteins)?
7-32mg/dL
130
What is the normal range for HDLs?
male: >45 mg/dL
female: >55 mg/dL
131
What is the normal range for triglycerides?
male: 40-160 mg/dL
female: 35-135 mg/dL
132
What is the normal range for pH?
7.35-7.45
133
What is the normal range for PCO2?
35-45 mmHg
134
What is the normal range for HCO3?
21-28 mEg/L
135
What is the normal range for PO2?
80-100 mmHg
136
What is the normal range for SaO2 saturation?
>95%
137
What is the normal range for Base excess?
0 ± 2 mEq/L
138
At what O2 rate is humidification necessary?
> 4L/min
139
What is the procedure that adds moisture or medication to inspired air by mixing particles of varying sizes with the air?
Nebulization
140
How does a nurse evaluate the effectiveness of coughing?
- sputum expectoration
- patient's report of swallowed sputum
- clearing of adventitious lung sounds
141
What are the 4 coughing techniques
- deep breathing and coughing
- cascade cough
- huff cough
- quad coughing
142
What are the 3 types chest physiotherapy (CPT) techniques?
- postural drainage
- chest percussion
- vibration
143
What are two examples of NPPV?
NPPV= noninvasive positive-pressure ventilation
1. Continuous positive airway pressure (CPAP)
2. Bilevel airway presure (BiPAP)
144
Which patients are treated with CPAP?
- obstructive sleep apnea
- heart failure
- preterm infants with underdeveloped lungs
145
What is the term for a catheter inserted through the thorax to remove air and fluids from the pleural space?
chest tube
146
What are chest tubes commonly used to treat?
pneumothorax or hemothorax to promote lung reexpansion
147
What is the term for a collection of air in the pleural space?
pneumothorax
148
What causes a pneumothorax?
The loss of negative intrapleural pressure which causes the lung to collapse
149
What does PEEP stand for?
Positive end-expiratory pressure
150
What is the term for the accumulation of blood and fluid in the pleural cavity between the parietal and visceral pleura?
hemothorax
151
What is the most serious tracheostomy complication?
airway obstruction
152
What is the junction where the trachea branches into the right and left mainstem bronchi?
carina
