Respiratory Care & Oxygenation

• Respiratory Care & Oxygenation is examined

Respiratory Physiology

• Intercostal muscles are present
• The lung has a pleural sac, parietal pleura and visceral pleura
• The diaphragm and pleural cavity are part of Respiratory Physiology

Upper Respiratory Tract

• Consists of the nose, mouth, pharynx, epiglottis, larynx, and trachea.

Lower Respiratory Tract

• Includes the bronchi, bronchioles, alveolar ducts, alveoli, and lung lobes.

Conducting Airways & Respiratory Unit Structure

• The trachea is part of the conducting airways
• Generations for the trachea is 0
• Bronchi and segmental bronchi have a generation of 8
• Sub-segmental bronchi have a generation of 15
• Non-respiratory bronchioles have a generation of 21-22
• Respiratory bronchioles have a generation of 24
• Alveolar ducts and alveoli have a generation of 28

Mechanism of Respiration: Inspiration

• The diaphragm descends and intercostal muscles contract leading to ribcage expansion
• Thoracic cavity volume increases, which leads to an increase in intrapulmonary volume and a decrease in intrapulmonary pressure
• With inspiration, air enters through the nose and mouth

Mechanism of Respiration: Expiration

• The diaphragm rises and intercostal muscles relax, causing the rib cages to descend.
• Thoracic cavity volume decreases, causing a decrease in intrapulmonary volume and an increase in intrapulmonary pressure.
• During expiration, gas flows out of the lungs

Regulation of Respiration

• Neural regulation involves the central nervous system controlling the respiratory rate, depth, and rhythm.
• The cerebral cortex regulates the voluntary control of respiration.
• Chemical regulation maintains the rate and depth of respirations based on changes in blood concentrations of CO2 and O2, as well as hydrogen ion concentration (pH)
• Chemoreceptors in the medulla, aortic body, and carotid body sense changes in the chemical content.

Steps in Oxygenation

• Ventilation is the process of moving gases into and out of the lungs.
• Diffusion is the exchange of respiratory gases in the alveoli and capillaries.
• Perfusion is the ability of the cardiovascular system to pump oxygenated blood to the tissues and return deoxygenated blood to the lungs.

Respiratory Gas Exchange

• The thickness of the alveolar capillary membrane affects the rate of diffusion.
• Oxygen transport involves the lungs and cardiovascular system.
• Hemoglobin carries both O2 and CO2.
• Carbon dioxide transport is important

Respiratory Defense Mechanism

• The respiratory system uses filtration of air, the mucociliary clearance system, cough reflex, reflex bronchoconstriction, and alveolar macrophages to defend itself

Terminology

• Work of breathing is the effort required to expand and contract the lungs during inspiration and expiration.
• Surfactant is the chemical produced in the lungs to maintain the surface tension of the alveoli and keep them from collapsing.
• Atelectasis is the collapse of the alveoli which prevents normal exchange of oxygen and carbon dioxide.
• Hypoxia is inadequate tissue oxygenation at the cellular level that is life-threatening and can lead to fatal cardiac issues if untreated.

More Terminology

• Hypercapnia is excessive CO2 in the bloodstream.
• Hyperventilation is inadequate alveolar ventilation to meet the oxygen demand or eliminate sufficient CO2, which leads to decreased CO2 and more alkaline blood
• Hypoventilation is a state of ventilation in which the lungs remove CO2 faster than produced by cellular metabolism. This leads to increased CO2 and more acidic blood
• Cyanosis is bluish discoloration of the skin and mucous membranes due to low oxygen levels.

Cardiovascular Physiology

• The cardiovascular system includes pulmonary arteries, pulmonary veins, the superior vena cava, and the aortic arch.
• The system also contains lobar branches to both the right and left lungs, capillary beds, the right and left lungs, the right and left ventricles, the right and left atria, and the inferior vena cava.

Cardiovascular Physiology Breakdown

• The myocardial pump consists of two atria and two ventricles.
• As the myocardium stretches, the strength of the subsequent contraction increases (Starling's law).
• Myocardial blood flow is unidirectional through four valves: S1 (mitral and tricuspid close) and S2 (aortic and pulmonic close)
• Coronary artery circulation involves the coronary arteries which supply the myocardium with nutrients and remove wastes.
• Systemic circulation involves the arteries and veins delivering nutrients and oxygen and removing waste products.

Ventilation and Oxygenation Diagnostic Studies

• The diagnostic studies that can be performed are arterial blood gases, mixed venous blood gases, the pulmonary Function Test, the Peak Expiratory Flow Rate, a Bronchoscopy, Pulse Oximetry and a Sputum specimen

Critical Blood Gas Values

• Adequate unless patient is hemodynamically unstable, or hemoglobin (Hgb) has difficulty releasing O2 to the tissues: PaO2 is ≥70 (%), SpO2 is ≥94 (%)
• Adequate in almost all patients, providing adequate oxygenation but with less margin for error: PaO2 is 60 (%), SpO2 is 90 (%)
• Adequate for patients with chronic hypoxemia if no cardiac problems occur: PaO2 is 55 (%), SpO2 is 88 (%)
• The values are used as criteria for prescription of continuous O2 therapy, and inadequate but may be acceptable on a short-term basis if the patient also has CO2 retention: PaO2 is 40 (%), SpO2 is 75 (%)
• Tissue hypoxia and cardiac dysrhythmias can be expected: PaO2 is <40 (%), SpO2 is <75 (%)
• The same critical values apply for SpO2 and SaO2 and pertain to rest or exertion.

Normal Arterial and Venous Blood Gas Values

• Assuming the patient is ≤60 yr of age and breathing room air: normal pH is 7.35-7.45
• At sea level BP of 760 mm Hg: normal PaO2t is 80-100 mm Hg, normal SaO2t is >95%+, normal PaCO2 is 35-45 mm Hg, normal HCO3 is 22-26 mEq/L (mmol/L)
• At 1 Mile Above Sea Level BP of 629 mm Hg: normal PaO2t is 65-75 mm Hg, normal SaO2t is >95%+, normal PaCO2 is 35-45 mm Hg, normal HCO3 is 22-26 mEq/L (mmol/L)
• Normal pH is 7.32-7.43, normal PvO2 is 38-42 mm Hg, normal SvO2 is 60%-80%+, normal PvCO₂ is 38-55 mm Hg, normal HCO3 is 22-26 mEq/L (mmol/L)

Factors Affecting Oxygenation

• Physiological factors
• Developmental factors
• Lifestyle factors
• Environmental factors

Physiological Factors

• Physiological factors are disorders that affect the body to meet oxygen demands, including respiratory and cardiac disorders.
• Respiratory disorders and cardiac disorders such as conduction disturbances (dysrhythmias) or impaired valvular function(stenosis or regurgitation) can play a role.
• Myocardial ischemia (angina pectoris/myocardial infarction) and altered cardiac output, such as heart failure (left or right), are factors that can affect oxygenation.

More Physiological Factors

• Physiological factors such as decreased oxygen-carrying capacity (anemia, carbon monoxide poisoning), hypovolemia (shock and severe dehydration), and decreased inspired oxygen concentration (high altitude, hypoventilation) can affect oxygenation.

Even More Physiological Factors

• Increased metabolic rates (pregnancy, wound healing, exercise, fever) can affect oxygenation.
• Conditions that reduce chest wall movement (pregnancy or obesity), and musculoskeletal abnormalities (flail chest, cerebral palsy) are also physiological factors
• Neuromuscular diseases (Guillain-Barre syndrome, myasthenia gravis, poliomyelitis) are factors affecting oxygenation.
• Conditions that affect the central nervous system (disease or trauma to the medulla oblongata, cervical trauma to C3-C5), phrenic nerve damage (controls diaphragm movement) are also factors

Developmental Factors

• Infants and toddlers have immature immune systems and have frequent upper respiratory infections.
• School-age children and adolescents also have risk of frequent upper respiratory infections and face risks associated with cigarette smoking in adolescents.
• Young and middle aged adults may have cardiopulmonary risk factors like unhealthy diet, lack of exercise, stress, smoking, and illegal substances
• Older adults are at higher risk for respiratory infections

Lifestyle Factors

• Nutrition, obesity which leads to decreased lung expansion and increased tissue oxygen demands. Malnourishment may also be a facture since it results in respiratory muscle wasting and decreased respiratory excursion and even anemia.
• 30-60 minutes of exercise increases efficiency of myocardial muscle
• Smoking can cause Nicotine, and it can also cause vasoconstriction, worsening peripheral vascular and coronary artery disease and COPD

Environmental Factors

• Urban areas can lead to pollution
• Exposure to occupational pollutants like asbestos, talcum powder, dust, and airborne fibers can affect oxygenation.
• Tobacco smoke can lead to a higher incidence of pneumonia, ear infections and asthma in children

Nursing Assessment - History

• Assess for chest pain, angina pectoris; immediate evaluation, location, duration radiation and frequency.
• Men feel pain on the left side of the chest with radiation to the left arm, women: less definitive symptoms: nausea, fatigue, breathlessness Pleuritic chest pain; inflammation or infection of the pleural space, which worsens with inspiration that is knifelike, lasting from minutes to hours
• Musculoskeletal pain; costochondritis (from prolonged coughing episodes), and/ or exercise

Nursing Assessment History includes Assessment for

• Fatigue: Subjective loss of endurance or can be an Early sign of worsening chronic disease, rating should be from 0-10
• Dyspnea, difficulty breathing, can be a clinical sign of hypoxia, can occur with exertion, stress or respiratory infections.
• Orthopnea the # of pillow needs or use Accessory muscles, nasal flaring or marked increase in rate and depth of respiration also rate from 0-10

Nursing Assessment - History

• Assess for; cough, to determine if it is Productive or nonproductive sputum, noting the Color, blood-tinged, consistency, odor, and amount.
• In case of hemoptysis, check for Bloody sputum, Alkaline pH
• In case of hematemesis, check for GI tract, and Acidic pH
• Note the duration of cough during assessment; Early morning or when rising: GERD or sinusitis
• Assess if the patient is wheezing

Nursing Assessment History includes

• Environmental geographical Exposures:
  • Carbon monoxide (CO)
  • Smoke
  • Occupational
• Determine; smoking: direct or indirect exposure to tobacco with a Pack-year history (packages per day x years)

Nursing Assessment - History

• Respiratory infections: noting the frequency and duration of respiratory tract infection (average: 4 per year), history of Vaccinations (pneumococcal, influenza), and HIV infection: opportunistic infections (P. carinii pneumonia)
• Note any Allergies and assess health risk:
• History of lung cancer or cardiovascular disease
• TB exposure
• Check if the patient is on any medication

Physical Examination – Inspection

• Check patients level of consciousness
• Note the patients Chest wall movement; any retractions – sinking in of soft tissues of chest between intercostal space and use of Accessory muscles
• Note the patients Breathing pattern; Apnea, Paradoxical breathing - chest wall contracts during inspiration and expands during exhalation, Kussmaul respiration – metabolic acidosis, Cheyne-Stokes respirations – periods of apnea with deep breathing
• Does pt use Tripod position, and what are that rate of Respirations:Normal adult: 12 to 20 regular breaths/min

Physical Examination - Palpation

• Palpation: Thoracic excursion, Fremitus Thrills Heaves, Cardiac point of maximal impulse (PMI)
• Peripheral Extremities: Capillary refills Peripheral pulses, Skin temperature and color
• Auscultation: Adventitious lung sounds

Nursing Diagnosis and Planning

• Activity intolerance: Impaired gas exchange or Risk for aspiration
• Fatigue; Impaired verbal communication or Ineffective health maintenance
• Decreased cardiac output; Impaired spontaneous ventilation or Ineffective breathing pattern or Risk for infection or Risk for suffocation
• Risk for imbalanced fluid volume

Goal Setting

• The Nursing diagnosis for goal setting is; Ineffective airway clearance related to the pulmonary secretions
• A goal should be; pulmonary secretions will return to baseline levels within 24 to 36 hours;
• A goal should be; patient's oxygenation status will improve in 36 hours

Implementation: Health Promotion

• Provide vaccinations for; influenza, pneumococcal
• Encourage a healthy lifestyle by; eliminating risk factors, eating right, regular exercise to promote patient wellness
• Educate environmental pollutants such as secondhand smoke, work chemicals, and pollutants

Acute Care Implementation

• Pharmacological agents; Bronchodilators, inhaled steroids, mucolytic, low dose anti-anxiety medications
• Oxygen therapy
• Physical techniques: Breathing techniques, Cough control and Relaxation techniques

Airway Management

• Ensure the Trachea, bronchi, large airways are free from obstruction
• Mobilization of pulmonary secretions; maintain clear airways by coughing or suctioning and decreases long recovery time and complications
• Hydration; Thins out secretions and is easily removable, and maintain 1500-2500 ml/day unless contraindicated
• Humidification, Necessary if patient is receiving oxygen (>4 L/min)
• Nebulization; Adds moisture and medication to inspired air by mixing particles of varying size to the air and Enhances mucociliary clearance for removal of mucus and cellular

Airway Management Techniques

• Coughing-Deep breathing; Post-operative with Q 2 hours while awake to prevent accumulation of secretions
• Cascade cough;Huff cough Quad cough during acute phase of mucus production
• Deep breathing Q 2 hours while awake with Cough Q 1 hour while awake and Cough Q 2 - 3 hours at night time. Deep inhalation increases lung volume and airway diameter and Allows air to move and pass through partially obstructed mucus plugs or foreign matter
• Chest physiotherapy (CPT)

Postural Drainage

• Refer to Table 40-6 in book, pg. 843 for positions for postural drainage.
• Positions are dependent on the area of the lung needing draining.

Suctioning Techniques

• Sterile technique required for suctioning; Oropharynx and trachea, and Suction oral secretions last
• Oropharyngeal and nasopharyngeal, Used when the patient can cough effectively, but is not able to clear secretions
• Suctioning of Orotracheal, nasotracheal patients; Used when the patient is unable to manage secretions
• In the case for Tracheal Suctioning Used with an artificial airway

Artificial Airways

• Oral airway, Prevent obstruction of the trachea by displacement of the tongue into the oropharynx
• Endotracheal-tracheal airways, Short term use, ventilate, relieve upper airway obstruction protect against aspiration, clear secretions
• Tracheostomy, Long term assistance, surgical incision made into trachea

Maintenance and Promotion of Lung Expansion

• Ambulation
• Positioning: Reduces pulmonary stasis and maintains ventilation and oxygenation
• Incentive spirometry: Encouraged voluntary deep breathing
• Noninvasive ventilation: Maintains positive airway pressure and improves alveolar ventilation

Maintenance and Promotion of Oxygenation

• Oxygen therapy should be used to prevent or relieve hypoxia
• Make sure the patient follows all safety precautions
• Supply of oxygen such as; Tanks or wall-piped system and Method of oxygen; Nascal canal or Oxygen mask

Oxygen Delivery Device

• Nasal Cannula; Flow rate up to 6 L/min, FIO2 range 24-40% oxygen, Flow rates >4 L/min must need humidifier and Be aware of skin breakdown over ears and nostrils from cannula and tight application
• Simple face mask (short term oxygen delivery) Flow rate: 6 to 10 L/min, Levels below 5 L/min can cause rebreathing of CO2 and FIO2 ranges from 40-60% and Contraindicated for patients with conditions with CO2 retention such as COPD)
• Non-Rebreather (Flow Rate: 10 L minimum range or FiO2 range: 60-80% with Valve between the bag and mask prevents exhaled air from returning into and the Bag should at least 1/3 to ½ full on inspiration and Deflated bag = breathing in large amount of exhaled CO2)
• Venturi mask withFlow rate: 4 to 12 L/min depending on flow meter selected and FiO2 range 24-60%

Atelectasis

• It a collapse of full or partial lung (alveoli) and it is mostly caused by post surgical procedures
• Can be avoided with Encourag[ing] deep breathing and incentive spirometer usage

Asthma

• Asthma is the chornic inflamatory disorder of air ways
• Leading to reversible episodes of wheezing, breathlessness, chest tightness and cough with triggers such as; allergies, exercise, cigarette smoking and GERD

Chronic Obstructive Pulmonary Disease (COPD)

• COPD is generally progressive with Irreversible airflow limitations during forced exhalation due to loss of elastic recoil and Airflow obstruction due to mucous hypersecretion, mucosal edema, and bronchospasm.
• Risk factors are; cigarette smoking, age >40 years, History: more than 10 years of smoking, occupational chemical and dust and or air pollution
• There area to types which are; Emphysema and Bronchitis which can be determined via observation

Question

• A nurse is caring for a patient whose temperature is 101.5 F. and expects patient to have rapid breathing this is due to increased metabolic demands
• What assessment finding is the earliest signs of hypoxia; restlessness and increased respiratory rate
• The nurse needs to closely monitor the oxygen status of an elderly patient undergoing anesthesia because of age-related change and also Decreased lung defense mechanisms cause ineffective airway clearance
• The nursing intervention that is most effective in preventing pneummonia in an elderly patients is assisting them to cough, turn and deep breathe every 2 hours