NCLEX-RN: Medical–Surgical Nursing

Medical–Surgical Nursing: Respiratory System

Focus topic: Medical–Surgical Nursing

The respiratory system is the body process that accomplishes pulmonary ventilation. The act of breathing involves an osmotic and chemical process by which the body takes in oxygen from the atmosphere and gives off end products, mainly carbon dioxide, formed by oxidation in the alveolar tissues. The respiratory system also works in conjunction with the kidneys in regulating acid–base balance.

Medical–Surgical Nursing: Anatomy of Respiratory System

Focus topic: Medical–Surgical Nursing

Medical–Surgical Nursing: Upper Airway

Focus topic: Medical–Surgical Nursing

A. Nasal passages.

  • Filter the air.
  • Warm the air.
  • Humidify the air.

B. Nasopharynx.

  • Tonsils: filter and destroy microorganisms.
  • Eustachian tube: opens during swallowing to equalize pressure in the middle ear.

C. Oropharynx.

  • Part of both the respiratory tract and the digestive tract.
  • Swallowing reflex initiated here.
  • Epiglottis closes entry to trachea as foodstuff passes en route to the stomach.

Medical–Surgical Nursing: Lower Airway

Focus topic: Medical–Surgical Nursing

A. Larynx.

  • Protects the tracheobronchial tree from aspiration of foreign materials.
  • Cough reflex initiated here, whether voluntary or involuntary.
  • Houses the vocal cords, which are considered to be the dividing point between the upper and lower airways.

B. Trachea.

  • Flexible cartilaginous tubular structure.
  • Extends from the cricoid cartilage into the thorax, branching into the right and left mainstem bronchi.

C. Right lung.

  • Contains three distinct lobes: upper, middle, and lower.
  • Lobes are divided by interlobar fissures.

D. Left lung.

  • Contains two lobes—upper and lower.
  • Lingula is part of the upper lobe but is sometimes referred to as the middle lobe of the left lung.
  • Lobes are divided by one interlobar fissure.

E. Bronchi.

  • Right mainstem bronchus (RMSB): shorter and wider than left bronchus; nearly vertical to trachea.
    a. Most frequent route for aspirated materials.
    b. Endotracheal tube might enter the RMSB if tube is passed too far.
  • Left mainstem bronchus (LMSB): branches off the trachea at a 45-degree angle.
  • The bronchi subdivide into bronchioles, terminal bronchioles, respiratory bronchioles, and alveoli.

F. Alveoli.

  • Air cells surrounded by pulmonary capillaries in which gas exchange takes place: oxygen, carbon dioxide.
  • Contain a substance known as surfactant, which keeps the alveoli expanded. Without surfactant, the alveoli would collapse.

G. Pleura.

  • Each lung enclosed in double-walled membrane sac. The parietal pleura lines the chest cavity. The visceral pleura lines the lungs. Space between the pleural layers is the intrapleural space and is filled with pleural fluid.
  • The pleural fluid is a thin film of fluid, encasing each lung, which allows for a smooth, gliding motion between the lung and the chest wall and facilitates expansion of lung during inspiration.

Medical–Surgical Nursing: Principles of Ventilation

Focus topic: Medical–Surgical Nursing

Medical–Surgical Nursing: Respiration

Focus topic: Medical–Surgical Nursing

Definition: A process in which oxygen is transported from the atmosphere to the cells and carbon dioxide is carried from the cells to the atmosphere.

A. Respiration is divided into four phases.

  • Pulmonary ventilation—air movement caused by intrathoracic pressure changes in relation to the pressure at the airway opening.
  • Diffusion of oxygen and carbon dioxide between alveoli and blood.
  • Transportation of oxygen and carbon dioxide in blood to and from cells.
  • Regulation of ventilation via respiratory center in medulla.

B. Respiratory cycle.

  • Inspiration (active process)—diaphragm descends and external intercostal muscles contract; alveolar pressure decreases, allowing air to flow into the lungs.
  • Expiration (normally a passive process)—muscles relax, alveolar pressure increases, allowing air to flow from the lungs.

Medical–Surgical Nursing: Respiratory Pressures

Focus topic: Medical–Surgical Nursing

A. At inspiration the intra-alveolar pressure is more negative than the atmospheric pressure.
B. At expiration the intra-alveolar pressure is more positive, thereby pressing the air out of the lungs.
C. A negative pressure exists in the intrapleural space and aids in keeping the visceral pleura of the lungs against the parietal pleura of the chest wall. Lung space enlarges as the chest wall expands.
D. Recoil tendency of the lungs is due to the elastic fibers in the lungs and the surfactant.

A. Surface-active material that lines the alveoli and changes the surface tension, depending on the area over which it is spread.
B. Surfactant in the lungs allows the smaller alveoli to have lower surface tension than the larger alveoli.

  • Results in equal pressures within both and prevents collapse.
  • Production of surfactant depends on adequate blood supply.

C. Conditions that decrease surfactant.

  • Hypoxia.
  • Oxygen toxicity.
  • Aspiration.
  • Atelectasis.
  • Pulmonary edema.
  • Pulmonary embolus.
  •  Mucolytic agents.
  • Hyaline membrane disease.

A. Relationship between pressure and volume: elastic resistance.

  • Measure of elasticity of lungs and thorax.
  • When compliance is decreased, lungs are more difficult to inflate.

B. Conditions that decrease chest wall compliance.

  • Obesity—excess fatty tissue over chest wall and abdomen.
  • Kyphoscoliosis—marked resistance to expansion of the chest wall.
  • Scleroderma—expansion of the chest wall limited when the involved skin over the chest wall becomes stiff.
  • Chest wall injury—as in crushing chest wall injuries.
  • Diaphragmatic paralysis—as a result of surgical damage to the phrenic nerve, or disease process involving the diaphragm itself.

C. Conditions that decrease lung compliance.

  • Atelectasis—collapse of the alveoli as a result of obstruction or hypoventilation.
  • Pneumonia—inflammatory process involving the lung tissue.
  • Pulmonary edema—accumulation of fluid in the alveoli.
  • Pleural effusion—accumulation of pleural fluid in the pleural space, compressing lung on the affected side.
  • Pulmonary fibrosis—scar tissue replacing necrosed lung tissue as a result of infection.
  • Pneumothorax—air present in the pleural cavity; lung is collapsed as volume of air increases.

Airway Resistance
A. Opposition or counterforce. Resistance depends on the diameter and length of a given tube (respiratory tract).

  • Flow may be laminar (smooth) or turbulent.
  • Resistance equals pressure divided by flow (Poiseuille’s law).

B. Conditions that increase airway resistance.

  • Secretions.
  • Bronchial constriction.

Lung Volumes
A. Total lung capacity (TLC)—total volume of air that is present in the lungs after maximum inspiration.
B. Vital capacity (VC)—volume of air that can be expelled following a maximum inspiration.
C. Tidal volume (TV)—volume of air with each inspiration.
D. Inspiratory reserve volume (IRV)—volume of air that can be inspired above the tidal volume.
E. Inspiratory capacity (IC)—volume of air with maximum inspiration; comprises tidal volume and inspiratory reserve volume.
F. Expiratory reserve volume (ERV)—volume of air that can be expelled following a resting expiration.
G. Reserve volume (RV)—volume of air remaining in the lungs at the end of maximum expiration.

H. Functional reserve capacity (FRC)—volume of air remaining in the lungs at the end of resting expiration; comprises ERV and RV.
I. Forced expiratory volume (FEV1)—volume of air of the vital capacity that is expelled within the first second.

Alveolar Ventilation
Definition: The rate at which the alveolar air is renewed each minute by atmospheric air—the most important factor of the entire pulmonary ventilatory process.

A. Rate of alveolar ventilation.

  • Alveolar ventilation is one of the major factors determining the concentrations of oxygen and carbon dioxide in the alveoli.
  • Alveolar ventilation per minute is the total volume of new air entering the alveoli each minute; equal to the respiratory rate times the amount of new air that enters the alveoli with each breath.

B. Anatomic dead space.

  • Dead space air is the air that fills the respiratory passages with each breath (nose to bronchioles).
  • The volume of air that enters the alveoli with each breath is equal to the tidal volume minus the dead space volume; usually 150 mL in adults. Air is not available for gas exchange.
  • Anatomical dead space refers to the volume of all spaces of the respiratory system besides the gas exchange areas (the alveoli and terminal ducts).
  • Physiological dead space refers to alveolar dead space (occurring because of nonfunctioning or partially functioning alveoli); included in the total measurement of dead space.
  • In the normal person, anatomical and physiological dead space are equal because all alveoli are functional.

Medical–Surgical Nursing: Oxygen and Carbon Dioxide Diffusion and Transportation of Respiratory Gases

Focus topic: Medical–Surgical Nursing

A. The first phase in respiration is ventilation, which is the constant replenishment of air in the lungs.
B. Composition of alveolar air.

  • Alveolar air is only partially replenished by atmospheric air each inspiratory phase.
    a. Approximately 350 mL of new air (tidal volume minus dead space) is exchanged with the functional residual capacity (FRC) volume each respiratory cycle (FRC = 2300 mL).
    b. Sudden changes in gaseous concentrations are prevented when alveolar air is replaced slowly.
  • Alveolar air contains more carbon dioxide and water vapor than atmospheric air.
  • Alveolar oxygen concentration depends on the rate of oxygen absorbed into the blood and the ability of the lungs to take in carbon dioxide.
  • Carbon dioxide content is likewise affected by the rate at which carbon dioxide is passed into the alveoli from the blood and the ability of the lungs to expire it.

Diffusion of Gases
A. The next phase is movement of oxygen from the alveolar air to the blood and movement of carbon dioxide in the opposite direction.
B. Movement of gases through the respiratory membrane depends on the following factors:

  • Thickness of membrane.
  • Permeability of membrane (diffusion coefficient).
  • Surface area of the membrane.
  • Differences in gas pressures in the alveolar and blood spaces.
  • Rate of pulmonary circulation.
  • The production of surfactant as it reduces the surface tension and aids in keeping the alveoli open.

C. Blood low in carbon dioxide and high in oxygen leaves lungs.
D. Throughout the body there again is exchange of respiratory gases in the capillary beds.

  • Oxygen out of the blood and into the cells.
  • Carbon dioxide from cells into the blood.

Oxygen Transport in the Blood
A. About 3% of the oxygen is carried in a dissolved state in the water of plasma and cells.
B. About 97% is carried in chemical combination with hemoglobin in red blood cells (RBCs).

  • The percentage of oxygen combined with each hemoglobin molecule depends on the partial pressure of oxygen (PO2).
  • The relationship is expressed as the oxygen–hemoglobin dissociation curve.
    a. It shows the progressive increase in the percentage of hemoglobin that is bound with oxygen as the PO2 increases.
    b. When the PO2 is high, oxygen binds with hemoglobin; when PO2 is low (tissue capillaries), oxygen is released from hemoglobin.
    c. This is the basis for oxygen transport from the lungs to the tissues.
  • Febrile states and acidosis permit less oxygen to bind with Hgb, thereby limiting the amount of oxygen available for the tissues.
  • The amount of oxygen that is available to the tissues depends on the oxygen content of the blood and the cardiac output.

C. Inadequate oxygen transport to the tissues—hypoxia.

  • Hypoxic hypoxia: low arterial PO2.
    a. Alveolar hypoventilation.
    b. Ventilation–perfusion inequalities.
    c. Diffusion defects.
    d. Fraction of inspired oxygen (FIO2) is less than atmosphere, such as in high altitudes.
  • Anemic hypoxia: decreased oxygen-carrying capacity to the blood.
    a. Anemia—less Hgb; therefore, less oxygen is able to combine with it.
    b. Carbon monoxide poisoning—carbon monoxide combines with Hgb, preventing oxygen from combining with Hgb.
  • Circulatory hypoxia: circulatory insufficiency.
    a. Shock—decreased cardiac output.
    b. Congestive heart failure.
    c. Arterial vascular disease—localized obstruction to arterial blood flow.
    d. Tissue need for oxygen surpasses supply available.
  • Histotoxic hypoxia: prevents tissues from utilizing oxygen.

Carbon Dioxide Transport in the Blood
A. A small amount of carbon dioxide is dissolved in plasma and red blood cells in the form of bicarbonate.
B. Inside the red blood cells, carbon dioxide combines with water to form carbonic acid.

  • It is catalyzed by the enzyme called carbonic anhydrase.
  • The enzyme accelerates the rate to a fraction of a second.

C. In another fraction of a second, carbonic acid dissociates to form hydrogen ions and bicarbonate in the red cells.
D. Carbon dioxide combines with the hemoglobin molecule.

  • The hemoglobin molecule has given off its oxygen to the tissues, and carbon dioxide attaches itself.
  • The venous system carries the combined carbon dioxide back to the lungs, where it is expired.

Medical–Surgical Nursing: Regulation of Respiration

Focus topic: Medical–Surgical Nursing

A. Respiratory centers.

  • Pons—two respiration areas: pneumotaxic and apneustic.
  • Medulla oblongata—major brain area controlling rhythmicity of respiration.
  • Spinal cord—facilitatory role in maintaining respiratory center.
  • Hering Breuer reflexes—stretch receptors located in lung tissue that assist in maintaining respiratory rhythm and prevent overstretch of the lung. Afferent fibers are carried in the vagus nerve.

B. Humoral regulation of respiration (chemical).

  • Central chemoreceptors.
    a. Directly stimulated by an increase in hydrogen ion concentration (acidity) in the cerebrospinal fluid.
    b. An increase in arterial PCO2 causes a rapid change in pH of the cerebrospinal fluid, increases the depth and rate of respiration, and decreases the PCO2 level.
    c. Changes in hydrogen ion and bicarbonate ion concentrations are not as quickly recognized as changes in the PCO2 by the central chemoreceptors; therefore, responses to metabolic imbalances are slower.
    d. Receptors are located in the medulla oblongata and adjacent structures.
  • Peripheral chemoreceptors.
    a. Receptor cells are located in the carotid body at the bifurcation of the common carotid arteries and at the aortic arch.
    b. Impulses from the aortic arch are transmitted to the brain via the vagus nerve.
    c. Impulses from the carotid body are transmitted to the brain via the glossopharyngeal nerve.
    d. The peripheral chemoreceptors primarily respond quickly to a decreased PO2 (below 50 mm Hg) and, to some extent, to alteration of the PCO2 and hydrogen ion concentration in the arterial blood.

Medical–Surgical Nursing: System Assessment

Focus topic: Medical–Surgical Nursing

A. Check for airway patency.

  • Clear out secretions.
  • Insert oral airway if necessary.
  • Position client on side if there is no cervical spine injury.
  • Place hand or cheek over nose and mouth of client to feel if client is ventilating.

B. Listen to lung sounds.

  • Absence of breath sounds: indicates lungs not expanding, due to either obstruction or deflation.
  • Crackles (rales): Indicate vibrations of fluid in lungs.
  • Rhonchi (coarse sounds): Indicate partial (fluid) obstruction of airway.
  • Decreased breath sounds: Indicate poorly ventilated lungs.
  • Detection of bronchial sounds that are deviated from normal position: Indicates mediastinal shift due to collapse of lung.
  • Where breath sounds are heard.
    a. Bronchovesicular—heard over mainstem bronchi.
    b. Vesicular (normal)—heard over lung parenchyma.
    c. Bronchial—heard over trachea above sternal notch.

C. Determine level of consciousness; decreased sensorium can indicate hypoxia.
D. Observe sputum or tracheal secretions; bloody sputum can indicate contusions of lung or injury to trachea and other anatomical structures.
E. Evaluate vital signs for temperature, respiratory rate, pulse, and changes in skin color.
F. Evaluate for tightness or fullness in chest.
G. Determine degree of pain client is experiencing.
H. Observe for PVCs if client is on monitor.
I. Assess for respiratory complications.

  • Breathing patterns.
  • Evaluate cough.
    a. Normally a protective mechanism utilized to keep the tracheobronchial tree free of secretions.
    b. Common symptom of respiratory disease.
  • Assess for bronchospasm.
    a. Bronchi narrow and secretions may be retained.
    b. Condition may lead to infection.
  • Observe for hemoptysis—expectoration of blood or blood-tinged sputum.
  • Assess for cyanosis—late sign of hypoxia, due to large amounts of reduced hemoglobin in the blood (PaO2 of about 50 mm Hg).
  • Observe for hypoxia (anoxia)—a deficiency of oxygen in the body tissues.
  • Evaluate for hypercapnia.
    a. Occurs when carbon dioxide is retained.
    b. High levels of oxygen depress and/or paralyze the medullary respiratory center.
    c. Peripheral chemoreceptors (sensitive to oxygen) become the stimuli for breathing.
  • Assess for presence of respiratory alkalosis or acidosis.

J. Assess for other system complications.

  • Evaluate for polycythemia—increase in RBCs as a compensatory response to hypoxemia.
  • Observe for clubbing of fingers. Pathogenesis is not well understood.
  • Evaluate for cor pulmonale—enlargement of the right ventricle as a result of pulmonary arterial hypertension following respiratory pathology.
  • Evaluate for chest pain.
  • Assess for atelectasis.
  • Check for abdominal distention.
  • Assess for hypertension.
  • Evaluate cardiac status: CHF, cerebral edema, arrhythmias.
  • Assess for trauma to thorax.

K. Assess oxygen concentration with noninvasive pulse oximetry.

  • Sensor probe on earlobe, finger, or toe registers light passing through vascular bed.
  • Allows continual monitoring of arterial oxygen saturation.

L. Assess for conditions associated with respiratory failure.

  • Infectious diseases: tuberculosis, pneumonia.
  • Obstruction of airway: pulmonary embolism, chronic bronchitis, bronchiectasis, emphysema, asthma, cardiac disorders leading to pulmonary congestion.
  • Restrictive lung disease: pleural effusion, pneumothorax, atelectasis, pulmonary tumors, obesity.
  • CNS depression: drugs, head injury, CNS infection.
  • Chest wall trauma: flail chest, neuromuscular disease, congenital deformities.

Medical–Surgical Nursing

Medical–Surgical Nursing: Diagnostic Procedures

Focus topic: Medical–Surgical Nursing

Radiologic Studies
A. Chest x-ray.
B. Lung scintigraphy: measures concentration of gamma rays from lung after intake of isotope.

C. Perfusion studies: outline pulmonary vascular structures after intake of radioactive isotopes IV. (Check for dye allergy.)
D. Computed tomography (CT).
E. Magnetic resonance imaging (MRI)—have client remove any metal before tests.

A. A flexible fiber-optic scope to visualize the interior of the tracheobronchial tree.
B. Used as a therapeutic tool to remove foreign materials; and for diagnosis, biopsy, specimen collection.
C. Nursing care.

  • Keep client NPO 6–8 hours before procedure.
  • Explain sedation and local anesthesia of nasal and oral pharynx.
  • Postprocedure: check client’s ability to control secretions. Keep NPO until gag reflex returns.
  • Observe for potential complications of laryngospasm, laryngeal edema, anesthesia complications, subcutaneous emphysema.
  • Client may expect hoarseness and sore throat.

Biopsy of Respiratory Tissue
A. May be done by needle, via bronchoscope, or an open lung procedure biopsy.
B. Nursing care: observe for hemothorax and/or pneumothorax.

A. A needle puncture through the chest wall to remove air or fluid.
B. Used for diagnostic and/or therapeutic purposes.
C. Nursing care: observe for possible pneumothorax postprocedure (↑ pulse, pallor, chest pain, dyspnea, tachycardia).

Pulmonary Function Tests
A. Measure of body’s ability to mechanically ventilate and to effect gaseous exchange.
B. Tests include spirometry, measurement of gas volume and airway resistance, diffusing capacity, and arterial blood gases.
C. Nursing care.

  • Avoid scheduling immediately after meals.
  • Hold bronchodilators (inhaled) for 6 hours prior to tests.

TB Tests
A. Mantoux skin test for tuberculosis.

  • The most reliable test to confirm infection.
  • 0.1 mL tuberculin injected intradermally—PPD is standard-strength purified protein derivative.
  • Test read 48–72 hours postintradermal wheal production.
  • Erythema not important.
  • Area of induration is more than 10 mm: indicates positive reaction (client has had contact with the tubercle bacillus). For HIV or severely immune suppressed, test is positive if induration is 5 mm or greater.
  • When skin test is positive, chest x-ray and sputum cultures important to rule out active TB or old, resolved TB lesions.
  • Reactions of 5–9 mm require retest.

B. Tine test not used.
C. Interferon gamma release assay (IGRA)—TB blood test.

  • This is a blood test used to determine if a person has been infected with TB bacteria.
  • Two IGRAs are approved by the U.S. Food and Drug Administration (FDA) and are available in the United States.
    a. QuantiFERON®–TB Gold In-Tube test (QFT–GIT).
    b. T–SPOT®.TB test (T–Spot).
  • Positive IGRA: Means the person has been infected with TB bacteria. Additional tests are needed to determine if the person has latent TB infection or TB disease.
  • Negative IGRA: This means that the person’s blood did not react to the test and that latent TB infection or TB disease is not likely.

Arterial Blood Studies
A. Arterial blood gases (ABGs).

  • Indicate respiratory function by measuring:
    a. Oxygen (PO2).
    b. Carbon dioxide (PCO2).
    c. pH.
    d. Oxygen saturation.
    e. Bicarbonate (HCO3).
  • Determine state of acid–base balance.
  • Reveal the adequacy of the lungs to provide oxygen and to remove carbon dioxide.
  •  Assess degree to which kidneys can maintain a normal pH.

B. Normal arterial values.

  • Oxygen saturation: 93–98%.
  • PaO2: 95 mm Hg.
  • Arterial pH: 7.35–7.45 (7.4).
  • PCO2: 35–45 mm Hg (40).
  • HCO3 content: 24–30 mEq (25).
  • Base excess: –3 to +3 (0).

Medical–Surgical Nursing: System Implementation

Focus topic: Medical–Surgical Nursing

A. Maintain patent airway.

  • Suction.
  • Intubation.
    a. Oral airway.
    b. Endotracheal intubation.

B. Maintain adequate ventilation.

  • Place in Fowler’s position to facilitate lung expansion.
  • Encourage coughing and breathing exercises.
  • If client needs help breathing, a ventilator may be used.
    a. Ventilator simulates breathing action usually provided by diaphragm and thoracic cage.
    b. Type of ventilator depends on specific needs of client.

C. Administer oxygen therapy using specific oxygen equipment according to the percentage of oxygen required by client with humidity therapy.
D. Monitor blood gases to determine how well client’s oxygen needs are being met.

E. Maintain fluid and electrolyte balance.

  • When blood and fluid loss are replaced, watch carefully for fluid overload, which can lead to pulmonary edema.
  • Record intake and output.

F. Maintain acid–base balance; make frequent blood gas determination as acid–base imbalances occur readily with compromised respirations or with mechanical ventilation.
G. Provide for relief of pain.

  • Analgesics should be used with caution as they depress respirations. (Demerol [meperidine] is the drug of choice.)
  • Atropine, morphine sulfate, and barbiturates should be avoided.
  • Nerve block may be used.

H. Perform electrocardiogram to establish associated cardiac damage.
I. Provide for incentive spirometry and chest physiotherapy.
J. Maintain hydration status.

  • Necessary to liquefy secretions or prevent formation of thick, tenacious secretions.
  • Monitor oral intake of fluids, IV administration of fluids, or humidification to tracheobronchial tree.

K. Administer appropriate drug therapy for respiratory condition.

Medical–Surgical Nursing: Hypoxic Condition

Focus topic: Medical–Surgical Nursing

Definition: Oxygen deficiency—the primary indication for initiation of oxygen therapy.

A. Check to see if client has a patent airway.
B. Assess client’s vital signs.
C. Observe existence of PVCs if client is on monitor.
D. Observe client for any of the following signs. If these signs are evident, you may need to administer oxygen.

  • Tachycardia.
  • Gasping and/or irregular respirations (dyspnea).
  • Restlessness.
  • Flaring nostrils.
  • Cyanosis.
  • Substernal or intercostal retractions.
  • Increased blood pressure followed by decreased blood pressure.
  • Abnormal ABGs.

E. Assess for side effects of oxygen therapy.

  • Atelectasis.
    a. Nitrogen is washed out of the lungs when a high FIO2 is delivered to client.
    b. In alveoli free of nitrogen, oxygen diffuses out of the alveoli into the blood faster than ventilation brings oxygen into the alveoli.
    c. This results in a collapse (atelectasis) of the affected alveoli.
  • Pulmonary oxygen toxicity.
    a. High FIO2 delivered over a long period of time (48 hours) results in destruction of the pulmonary capillaries and lung tissue.
    b. The clinical picture resembles that of pulmonary edema.
  • Retrolental fibroplasia.
    a. Blindness resulting from high FIO2 delivered to premature infants.
    b. This condition is seen in prolonged FIO2 of 100% when high levels of oxygen are not needed.
  • Carbon dioxide narcosis.
    a. Carbon dioxide narcosis can develop if hypoxic drive is removed by administering FIO2 to return the arterial PO2 to normal range.
    b. Symptoms of carbon dioxide narcosis.
    (1) Decreased mentation.
    (2) Flushed, pink skin.
    (3) Flaccid (sometimes twitching) extremities.
    (4) Shallow breathing.
    (5) Respiration arrest.

F. Evaluate client for clinical manifestations of COPD.

  • Ventilatory drive is hypoxemic.
  • Oxygen administration requires critical observation. Start at 2 L/min.

Medical–Surgical Nursing


A. Monitor lung sounds for adequate ventilation.
B. Monitor client for signs of oxygen toxicity.
C. Provide skin care for areas surrounding oxygen equipment.
D. Administer oxygen at appropriate flow with specified equipment.

  • Nasal prongs and cannula.
    a. Easily tolerated by clients.
    b. The FIO2 will vary depending on the flow.
    (1) FIO2: 24–28%. Flow: 1–2 L.
    (2) FIO2: 30–35%. Flow: 3–4 L.
    (3) FIO2: 38–44%. Flow: 5–6 L.
  • Simple face mask.
    a. Requires fairly high flows to prevent rebreathing of carbon dioxide.
    b. Accurate FIO2 difficult to estimate.
    c. FIO2: 35–65%. Flow: 8–12 L.
  • Mask with reservoir bag.
    a. Higher FIO2 is delivered because of the reservoir.
    b. At flows less than 6 L/min, risk of rebreathing carbon dioxide increases.
    (1) Partial rebreathing mask:
    FIO2: 40–60%. Flow: 6–10 L.
    (2) Nonrebreather: FIO2: 60–100%. Flow: 6–15 L.
  • Venturi mask.
    a. Delivers fixed or predicted FIO2.
    b. Utilized effectively in clients with COPD when accurate FIO2 is necessary for proper treatment.
    c. FIO2: 24–50%.
  • Face tent.
    a. Well tolerated by clients but sometimes difficult to keep in place.
    b. Convenient for providing humidification with compressed air in conjunction with nasal prongs.
    c. FIO2: 28–100%. Flow: 8–12 L.
  • Oxygen hood.
    a. Hood fits over child’s head.
    b. Provides warm, humidified oxygen at high concentrations.
    c. FIO2: 28–85%. Flow: 5–12 L.
  • Intratracheal oxygen device for long-term therapy.




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