Oxygen and Respiratory Function in Older Adults

• Oxygen, approximately 21% of Earth's atmosphere, is essential for sustaining life
• Each human cell utilizes it to metabolize nutrients and produce energy
• Oxygen deprivation rapidly leads to cell death

Gerontologic Considerations

• Reduced gas exchange and ventilation efficiency are age-related changes impacting respiratory function in older adults
• Functional respiratory changes include diminished cough/gag reflexes, increased accessory muscle use, reduced gas exchange efficiency, and more mouth breathing/snoring
• Lung volume changes can result in decreased efficiency and increased energy expenditure in older adults
• Confusion or restlessness in older adults requires careful assessment to differentiate inadequate oxygenation from delirium or dementia
• Older adults on home oxygen need encouragement to socialize to prevent isolation/depression and education on portable oxygen
• Assess the skin behind the ears for breakdown from oxygen equipment tubing
• Weight loss impacting facial seal may affect prescribed oxygen amounts via mask in older adults
• Older adults should receive annual influenza immunizations and pneumonia immunizations after age 65, or earlier with chronic illness
• A booster dose is recommended for those who received initial pneumonia immunization 5+ years prior

Anatomy and Physiology of Breathing

• Lung tissue elasticity allows stretching during inspiration and return to resting position after expiration
• Ventilation (air movement in/out of lungs) facilitates respiration(gas exchange)
• External respiration occurs between alveolar and capillary membranes
• Internal respiration occurs at the cellular level via hemoglobin and body cells
• Increased carbon dioxide and hydrogen ions stimulate breathing neurologically and chemically in people without respiratory disease
• Ventilation occurs due to pressure changes in the thoracic cavity from respiratory muscle contraction & relaxation
• Inspiration involves diaphragm contraction/downward movement and intercostal muscle elevation of ribs/sternum, expanding the thoracic cavity
• Chest cavity expansion reduces lung pressure, drawing air in
• Expiration involves respiratory muscle relaxation, thoracic cavity decrease, and elastic lung tissue recoil, increasing intrathoracic pressure and expelling air
• Abdominal muscle contraction can forcibly exhale additional air

Assessing Oxygenation

• The nurse assesses oxygenation quality with data from physical assessments, arterial blood gases (ABGs), and pulse oximetry
• A combination of these measures identifies hypoxemia (insufficient oxygen in arterial blood) and hypoxia (inadequate oxygen at the cellular level)

Physical Assessment

• Respiratory rate monitoring and breathing pattern/effort observation is key to assessing oxygenation
• Chest symmetry check & lung sound auscultation are important
• Assessing heart rate, blood pressure, consciousness level, skin color, mucous membranes, lips and nail beds is key
• Common signs of inadequate oxygenation include decreased energy, restlessness, rapid/shallow breathing, rapid heart rate, needing to sit up, nasal flaring, accessory muscle use, hypertension, sleepiness, confusion, stupor, and coma

Artery Blood Gases

• ABG assessment is a laboratory test using arterial blood to evaluate/assess oxygenation, ventilation, and acid-base balance
• Measures partial pressure of oxygen in plasma (PaO2), hemoglobin oxygen saturation(SaO2), partial pressure of carbon dioxide in plasma(PaCO2), blood pH and bicarbonate(HCO3)levels
• Arterial blood is preferred for sampling because arteries have more oxygen content
• Initial and subsequent ABGs assess acute respiratory distress or monitor client medical treatment progress
• A laboratory technician and the nurse collaboratively collect arterial blood
• The nurse notifies the lab of blood test needs, records assessments on the request form, prepares the client, assists with specimen collection, and prevents puncture complications emergently
• Key steps for ABG assistance include performing Allen's test to ensure adequate ulnar arterial blood supply, resting the client, recording temperature, respiratory rate, activity level, and supplemental oxygen information
• To assist with an ABG draw, hyperextend the wrist, comfort the client, expel air bubbles from the specimen, rotate the specimen, place the sample on ice, apply direct manual pressure and a pressure dressing, and assess/report lab findings

Promote Oxygenation

• Positioning and breathing techniques are common nursing interventions
• Adhesive nasal strips can improve oxygenation by reducing nasal airway resistance and improving ventilation

Positioning

• Patients with hypoxia are placed in High Fowler's position to promote ease of breathing
• Tripod position can also be utilized to promote breathing capacity.
• Orthopneic position can also promote room for maximum vertical and lateral chest expansion.

Breathing exercise

• Various breathing techniques encourage clients to breathe more efficiently
• Deep breathing maximizes ventilation
• Incentive spirometry is deep breathing using a calibrated device
• Pursed-lip breathing prolongs expiration to eliminate more carbon dioxide
• Diaphragmatic breathing uses the diaphragm instead of upper chest muscles.

Oxygen Therapy

• Oxygen therapy requires an oxygen source, regulator, and delivery device
• Oxygen sources include wall outlets, portable tanks, liquid oxygen units, and oxygen concentrators
• Oxygen therapy supports interventions to improve blood-oxygen saturation.

Oxygen administration equipment

• A flow meter is a gauge used to regulate the volume of oxygen delivered to the patient.
• An oxygen analyzer measures the percentage of delivered oxygen
• A humidifier may be used during oxygen administration.

Oxygen Delivery Devices:

• Nasal Cannula
• Masks
• Face Tent
• Tracheostomy collar
• T-piece

Nasal Cannula

• A nasal cannula is a hollow tube with ½ inch prongs placed in the client's nostrils held in place by wrapping the tubing around the ears.
• Provides low concentration oxygen
• High oxygen percent is not indicated in chronic disease patients

Masks

• The masks allows for administration of higher levels of oxygen.
• Simple Masks: Fitm over the nose and mouth and allows atmospheric air in.
• Partial Rebreather Mask: Oxygen delivery device in which the client inherits a mixture of atmospheric air oxygen from its source, and oxygen contains within a reservoir bag.
• Nonbreather Mask: Oxygen delivery device which all exhaled air leaves the mask rather than partially entering the reservoir bag.
• Venturi mark: Mixes precise amount of oxygen and atmospheric air.
• Face Tent: Provides oxygen without discomfort or mask.
• Tracheostomy collar: Delivers oxygen hear an artificial opening in the neck, provides oxygen and humidification.
• T-piece: Fits security onto a tracheostomy tube or endotracheal tube.

Oxygen Hazards

• Includes oxygen's capacity to support fires
• Long term use of oxygen may lead to oxygen toxicity

Hypoxia

• Hypoxia involves lung damage
• Administer the lowest FIO2 possible for the least amount of time.
• Use Positive Airway Pressure Machines
• Water-seal Tube Drainage
• Hyperbaric Oxygen Therapy

Positive Airway Pressure Machines

• Relief impaired oxygen levels caused by temporary relaxation of the muscles
• CPAP: (Continuous Air Pressure Machines) CPAP's Mask is a portable ventilator.
• BiPAP: (Bilevel Positive Airway Pressure) Device provides two different levels of airway pressure.

Nursing Implications

• Altered breathing patterns
• Impaired gas exchange
• Activity Intolerance
• Chronic/acute anxiety
• Risk for ineffective airway clearance