Oxygenation Flashcards
Characteristics of the Trachea
-4 – 5 inches long
-Extends from the larynx to the primary bronchi
What is the primary function of the lungs?
transfer oxygen from the atmosphere into the alveoli and carbon dioxide out of the body as a waste product
What is the function of the alveolar capillary membrane?
oxygen transfers to the blood, and carbon dioxide transfers from the blood to the alveoli.
Alveoli
Where o2 is exchanged for co2
Name and explain the steps of oxygenation
Ventilation: The process of moving gases into and out of the lungs
Perfusion: The ability of the cardiovascular system to pump oxygenated blood to the tissues and return deoxygenated blood to the lungs
Diffusion: Exchange of respiratory gases in the alveoli and capillaries
Inspiration/Expiration
An active process stimulated by chemical receptors in the aorta; a passive process for expiration
Pulmonary Circulation
Moves blood to and from the alveolar capillary membranes for gas exchange
Carbon dioxide transport
Diffuses into red blood cells and is hydrated into carbonic acid
How are normal lung values determined?
Age
Gender
Height
Tidal Volume
Amount of air exhaled after normal inspiration
Residual Volume
The amount of air left in the alveoli after a full expiration
Forced Vital Capacity (FVC)
Maximum amount of air that can be removed from the lungs during forced expiration
Spirometry
Measures the volume of air entering or leaving the lun
What are two types of respiratory regulation?
Neural Regulation (CNS)
-rate, depth and rhythm
Chemical Regulation
-Maintain rate and depth of respirations based on changes of CO2 and O2, and in hydrogen ion concentration (pH) in blood
Why is respiratory regulation necessary?
To ensure sufficient oxygen intake and carbon dioxide elimination to meet the demands of the body (e.g., during exercise, infection, or pregnancy
What is diffusion in the respiratory system?
Process for exchange of respiratory gases in the alveoli and capillaries of the body tissues. Takes place at alveolar capillary membrane
What can affect the thickness of the alveolar membrane and why does that matter?
Increased thickness of the membrane impedes diffusion because gases take longer to transfer across the membrane. Patients with pulmonary edema, pulmonary infiltrates, or pulmonary effusion have a thickened membrane, resulting in slow diffusion, slow exchange of respiratory gases, and decreased delivery of oxygen to tissues. Chronic diseases (e.g., emphysema), acute diseases (e.g.,
What is hemoglobin?
Carrier for oxygen and carbon dioxide, transports most oxygen (approximately 97%)
Cardiac Output
Amount of blood ejected from the left ventricle each minute
Normal: 4-6 L/m
Stroke Volume
Amount of blood ejected from the left ventricle with each contraction
Cardiac output (CO) =
Stroke volume (SV) × Heart rate (HR)
Preload
End-diastolic pressure
Afterload
Resistance to left ventricular ejection
What are some examples of physiological factors that affect oxygenation?
Decreased oxygen-carrying capacity
Hypovolemia
Decreased inspired oxygen concentration
Increased metabolic rate
What are some conditions that affect chest wall movement?
Pregnancy, obesity, neuromuscular disease, musculoskeletal abnormalities, trauma, CNS alterations
Chronic Diease
Respirtory Assessment
Hyperventilation
Ventilation in excess of that required to eliminate carbon dioxide produced by cellular metabolism
Hypoventilation
Alveolar ventilation inadequate to meet the body’s oxygen demand or to eliminate sufficient carbon dioxide
What can cause hyperventilation?
anxiety, infection, drugs, acid-base imbalance, fever, aspirin poisoning, or amphetamine use.
What can cause hypoventilation?
atelectasis and collapsed alveoli
What are some causes of hypoxia?
anemia, carbon monoxide poisoning, septic shock, cyanide poisoning, pneumonia atelectasis, cardiomyopathy, spinal cord injury, and head trauma
What are causes of cyanosis?
Late stages of hypoxia
What are examples of life threatening arrhythmias?
Ventricular tachycardia is a life-threatening dysrhythmia caused by decreased cardiac output with the potential to deteriorate into ventricular fibrillation or sudden cardiac death.
What causes backflow of blood and what assessment supports that diagnosis?
Valvular dysfunction
On assessment, pt. would present with murmur or whooshing sound
What are some developmental factors that affect oxygenation in infants and toddlers?
upper respiratory infections (URIs), nasal congestion
What are some developmental factors that affect oxygenation in school aged children and adolescents?
exposed to respiratory infections and secondhand smoke; plus danger of starting cigarette smoking
What are some developmental factors that affect oxygenation in young to middle aged adults?
exposed to cardiopulmonary factors, unhealthy diet, lack of exercise, stress, cigarette smoking, illegal substances; over-the-counter (OTC) and prescription drugs not used as intended
What are some developmental factors that affect oxygenation in older adults?
calcification of valves, SA node, and costal cartilages; osteoporosis; atherosclerosis; enlarged alveoli, trachea, and bronchi
What are things to include during the cardiopulmonary assessment of a pt?
Past impairments in circulatory/respiratory function
Oxygenation uses
Physical exams
Lab/diagnostic tests
What do we inspect during the physical exam?
Skin and mucous membranes, level of consciousness (LOC), breathing patterns, chest wall movement
What do we palpate during a physical exam?
Chest, feet, legs, pulses
What does percussion asses?
Presence of abnormal fluid or air; diaphragmatic excursion
What do we listen for during auscultation?
Normal and abnormal heart and lung sounds
How can nurses promote lung expansion?
mobility, positioning, incentive spirometry, and chest tube insertion
What position promotes lung expansion and why?
45 degree semi-fowlers uses gravity to assist in lung expansion and reduces pressure from the abdomen on the diaphragm
What does the incentive spirometer treat/prevent?
Prevent/treats atelectasis
How do we instruct patients when using the incentive spirometer?
A patient inhales slowly and with an even flow to elevate the balls and keep them floating as long as possible to ensure a maximally sustained inhalation.
What pts. does the CPAP treat?
obstructive sleep apnea, those with congestive heart failure, and preterm infants with underdeveloped lungs
What is orthopnea Posture and why is it seen in pts with respiratory problems?
Pt. sits upright with hands/elbows resting upon some support. It is easier to breathe while sitting upright and give space for the lung to expand greater
True/False
Oxygen is a drug
True
What is important to assess with pts. on oxygen?
Skin integrity of the ears, nares, and bridge of the nose
What is Fio2
Percentage of oxygen-inspired concentration
What is the highest flow on the nasal cannula?
up to 6L
When is a humidfer indicated for pts on o2?
Any flow rate above 4Ls and if as pt complains of dry nares
What is the highest flow rate of a high-flow nasal cannula? What color should the tubing be?
Up to 60L
Green
Fio2 percentage for 1-6L on the nasal cannula?
1L/minute = 24%
2L/minute = 28%
4L/minute = 36%
6L/minute = 44%
