Chapter 20: Respiratory Management and Mechanical Ventilation

Chapter 20: Respiratory Management and Mechanical Ventilation

Oxygen Basics

• Oxygen is a tasteless, colorless gas.

• Makes up ~21% of atmospheric air.

Purpose of Oxygen Therapy

• Maintains adequate cellular oxygenation.

• Used to treat acute and chronic respiratory conditions.

Oxygen Administration Goals

• Maintain SaO₂ between 95%–100%.

• Use the lowest effective oxygen concentration.

• Prevent oxygen-related complications (oxygen toxicity, CO₂ retention).

Mechanical Ventilation Overview

• Required when a client cannot breathe spontaneously.

• Provides respiratory support in the following situations:

  • Severe respiratory disease (impaired ventilation or gas exchange).

  • General anesthesia (suppressed respiratory drive).

  • Trauma (neurologic or thoracic impairment).

  • Other critical illnesses affecting breathing.

Key NCLEX Focus

• Oxygen is a medication.

• Always titrate oxygen to the lowest dose that achieves target saturation.

• Mechanical ventilation replaces or supports spontaneous breathing, not just oxygen delivery.

Oxygen Delivery Devices

Supplemental oxygen is delivered based on the client’s condition and oxygenation needs.

Oxygen concentration is expressed as FiO₂ (fraction of inspired oxygen).

Continuously monitor vital signs and SaO₂.

Adjust therapy based on response and clinical status.

Nasal Cannula

Tubing with two small prongs inserted into the nares.

FiO₂ 24%–44% at 1–6 L/min.

Advantages

• Safe, simple, comfortable, well tolerated.

• Allows eating, talking, and ambulation.

Disadvantages

• FiO₂ varies with flow rate and depth of breathing.

• Prolonged use can cause skin breakdown and dry mucous membranes.

• Easily dislodged.

Nursing Actions

• Assess patency of nares.

• Ensure proper prong fit.

• Use water-soluble lubricant for dry nares.

• Add humidification at ≥4 L/min.

Simple Face Mask

Covers nose and mouth.

FiO₂ 35%–60% at 5–10 L/min.

Minimum flow 5 L/min to flush CO₂.

Advantages

• Easy to apply.

• May be more comfortable than a nasal cannula.

Disadvantages

• Flow <5 L/min causes CO₂ rebreathing.

• Poor tolerance with anxiety or claustrophobia.

• Interferes with eating, drinking, talking.

• Aspiration risk with vomiting or decreased LOC.

• Moisture and pressure can cause skin breakdown.

Nursing Actions

• Ensure snug fit over nose and mouth.

• Switch to nasal cannula during meals.

Partial Rebreather Mask

Covers nose and mouth.

FiO₂ 50%–90% at 10–15 L/min.

Advantages

• Reservoir bag without valves allows rebreathing of up to one-third exhaled air.

Disadvantages

• Reservoir bag deflation causes CO₂ buildup.

• FiO₂ varies with breathing pattern.

• Poor tolerance with anxiety or claustrophobia.

• Interferes with eating and talking.

• Aspiration risk.

Nursing Actions

• Keep reservoir bag inflated.

• Assess mask fit and skin integrity.

• Monitor bridge of nose and mask edges.

• Use nasal cannula during meals.

Nonrebreather Mask

Covers nose and mouth.

FiO₂ 80%–95% at 10–15 L/min.

Reservoir bag should remain two-thirds full.

Advantages

• Highest oxygen concentration without intubation.

• One-way valves prevent room air entry.

Disadvantages

• Valves and flaps must function properly.

• Poor tolerance with anxiety or claustrophobia.

• Interferes with eating and talking.

• Aspiration risk.

Nursing Actions

• Check valves and flaps at least hourly.

• Ensure proper seal.

• Monitor skin integrity.

• Use nasal cannula during meals.

Low-Flow Oxygen Delivery Systems

Nasal Cannula

• Tubing with two small prongs inserted into the nares.

• FiO₂ 24%–44% at 1–6 L/min.

Advantages

• Safe, simple, comfortable, well tolerated.

• Allows eating, talking, and ambulation.

Disadvantages

• FiO₂ varies with flow rate and depth of breathing.

• Prolonged use can cause skin breakdown and dry mucous membranes.

• Easily dislodged.

Nursing Actions

• Assess patency of nares.

• Ensure proper prong fit.

• Use water-soluble lubricant for dry nares.

• Add humidification at ≥4 L/min.

Simple Face Mask

• Covers nose and mouth.

• FiO₂ 35%–60% at 5–10 L/min.

• Minimum flow 5 L/min to flush CO₂.

Advantages

• Easy to apply.

• May be more comfortable than a nasal cannula.

Disadvantages

• Flow <5 L/min causes CO₂ rebreathing.

• Poor tolerance with anxiety or claustrophobia.

• Interferes with eating, drinking, talking.

• Aspiration risk with vomiting or decreased LOC.

• Moisture and pressure can cause skin breakdown.

Nursing Actions

• Ensure snug fit over nose and mouth.

• Switch to nasal cannula during meals.

Partial Rebreather Mask

• Covers nose and mouth.

• FiO₂ 50%–90% at 10–15 L/min.

Advantages

• Reservoir bag without valves allows rebreathing of up to one-third exhaled air.

Disadvantages

• Reservoir bag deflation causes CO₂ buildup.

• FiO₂ varies with breathing pattern.

• Poor tolerance with anxiety or claustrophobia.

• Interferes with eating and talking.

• Aspiration risk.

Nursing Actions

• Keep reservoir bag inflated.

• Assess mask fit and skin integrity.

• Monitor bridge of nose and mask edges.

• Use nasal cannula during meals.

Nonrebreather Mask

• Covers nose and mouth.

• FiO₂ 80%–95% at 10–15 L/min.

• Reservoir bag should remain two-thirds full.

Advantages

• Highest oxygen concentration without intubation.

• One-way valves prevent room air entry.

Disadvantages

• Valves and flaps must function properly.

• Poor tolerance with anxiety or claustrophobia.

• Interferes with eating and talking.

• Aspiration risk.

Nursing Actions

• Check valves and flaps at least hourly.

• Ensure proper seal.

• Monitor skin integrity.

• Use nasal cannula during meals.

Venturi Mask

Covers nose and mouth.

FiO₂ 24%–60% at 10–15 L/min using color-coded adapters.

Advantages

• Most precise oxygen concentration without intubation.

• No humidification required.

• Ideal for chronic lung disease (controlled oxygen delivery).

Disadvantages

• More expensive.

Nursing Actions

• Verify correct adapter and flow rate.

• Ensure tubing is free of kinks.

• Monitor skin around mask and nares.

• Use nasal cannula during meals.

Aerosol Mask, Face Tent, Tracheostomy Collar

Loose-fitting devices for face or tracheostomy.

FiO₂ 24%–100% at ≥10 L/min.

Provide high humidification.

Advantages

• Useful when masks are not tolerated.

• Ideal for facial trauma, burns, thick secretions.

Disadvantages

• Requires frequent monitoring due to high humidity.

Nursing Actions

• Empty condensation from tubing frequently.

• Ensure adequate water in humidifier.

• Verify visible mist during inspiration and expiration.

• Prevent tubing from pulling on tracheostomy.

T-Piece

Used with tracheostomy, laryngectomy, or ET tube.

FiO₂ 24%–100% at ≥10 L/min.

Advantages

• Delivers humidified oxygen directly to artificial airway.

Disadvantages

• High humidification requires frequent monitoring.

Nursing Actions

• Keep exhalation port open.

• Prevent traction on tracheostomy or ET tube

• Ensure visible mist during inspiration and expiration.

High-Flow Oxygen Delivery Systems

Deliver precise FiO₂ when properly fitted.

Venturi Mask

• Covers nose and mouth.

• FiO₂ 24%–60% at 10–15 L/min using color-coded adapters.

Advantages

• Most precise oxygen concentration without intubation.

• No humidification required.

• Ideal for chronic lung disease (controlled oxygen delivery).

Disadvantages

• More expensive.

Nursing Actions

• Verify correct adapter and flow rate.

• Ensure tubing is free of kinks.

• Monitor skin around mask and nares.

• Use nasal cannula during meals.

Aerosol Mask, Face Tent, Tracheostomy Collar

• Loose-fitting devices for face or tracheostomy.

• FiO₂ 24%–100% at ≥10 L/min.

• Provide high humidification.

Advantages

• Useful when masks are not tolerated.

• Ideal for facial trauma, burns, thick secretions.

Disadvantages

• Requires frequent monitoring due to high humidity.

Nursing Actions

• Empty condensation from tubing frequently.

• Ensure adequate water in humidifier.

• Verify visible mist during inspiration and expiration.

• Prevent tubing from pulling on tracheostomy.

T-Piece

• Used with tracheostomy, laryngectomy, or ET tube.

• FiO₂ 24%–100% at ≥10 L/min.

Advantages

• Delivers humidified oxygen directly to artificial airway.

Disadvantages

• High humidification requires frequent monitoring.

Nursing Actions

• Keep exhalation port open.

• Prevent traction on tracheostomy or ET tube

• Ensure visible mist during inspiration and expiration.

A nurse is caring for a client who has dyspnea and will receive oxygen continuously. Which of the following oxygen devices should the nurse use to deliver a precise amount of oxygen to the client?

a

Non-rebreather mask

b

Nasal cannula

c

Venturi mask

d

Tracheostomy collar

c

Venturi mask

NCLEX Focus

Low-flow systems deliver variable FiO₂.

High-flow systems deliver precise FiO₂.

Nonrebreather masks are for short-term, high-acuity oxygen needs.

Humidification is essential with high flows or artificial airways.

Oxygen Therapy

Indications

• Treatment of hypoxemia and hypoxia.

Potential Diagnoses

• Hypoxemia

  • Inadequate oxygen level in the blood.

  • Caused by hypovolemia, hypoventilation, or impaired arterial blood flow.

• Hypoxia

  • Decreased tissue oxygenation.

Client Presentation

Early Findings

• Tachypnea

• Tachycardia

• Restlessness

• Pale skin and mucous membranes

• Elevated blood pressure

• Signs of respiratory distress:

  • Use of accessory muscles

  • Nasal flaring

  • Tracheal tugging

  • Adventitious lung sounds

Late Findings

• Confusion or stupor

• Cyanotic skin and mucous membranes

• Bradypnea

• Bradycardia

• Hypotension

• Cardiac dysrhythmias

Oxygen Therapy Considerations

Preparation of the Client

• Explain procedures to reduce anxiety.

• Position in semi-Fowler’s or Fowler’s (improves chest expansion).

• Verify oxygen equipment is functioning properly.

Ongoing Care

• Administer oxygen at the lowest flow rate that corrects hypoxemia.

• Monitor:

  • Respiratory rate, rhythm, effort

  • Lung sounds

  • SaO₂

• Assess for:

  • Hypoxemia: dyspnea, anxiety, tachypnea, tachycardia, restlessness, pallor or cyanosis, adventitious sounds, confusion.

  • Hypercarbia (↑ CO₂): restlessness, hypertension, headache.

• Review diagnostics related to oxygenation (ABGs).

• Promote oral hygiene.

• Encourage turning, coughing, deep breathing, incentive spirometry, suctioning as needed.

• Promote rest and reduce environmental stimuli.

• Provide emotional support for anxiety.

• Assess nutritional status and provide supplements as prescribed.

• Monitor skin integrity and use pressure-relief or moisture-barrier measures.

• Document response to oxygen therapy.

• Titrate oxygen to prescribed saturation goals.

• Discontinue supplemental oxygen gradually.

Interventions

Respiratory Depression

• Monitor for decreased respiratory rate and decreased level of consciousness.

• Notify the provider if present.

Respiratory Distress

• Position in Fowler’s or semi-Fowler’s.

• Perform focused respiratory assessment.

• Encourage deep breathing.

• Administer supplemental oxygen as prescribed.

• Stay with the client to reduce anxiety.

• Promote airway clearance (coughing, oral or oropharyngeal suctioning).

Oxygen Therapy Complications

Oxygen Toxicity

• Risk factors:

  • FiO₂ >50%

  • Prolonged therapy (>24–48 hours)

  • Underlying lung disease

• Manifestations:

  • Nonproductive cough

  • Substernal chest pain

  • Nasal stuffiness

  • Nausea and vomiting

  • Fatigue

  • Headache

  • Sore throat

  • Hypoventilation

Nursing Actions

• Use the lowest FiO₂ needed to maintain prescribed SaO₂.

• Monitor ABGs and notify provider of abnormal results.

• Use CPAP or BiPAP if prescribed to reduce oxygen requirement.

• Use PEEP during mechanical ventilation as prescribed.

Oxygen-Induced Hypoventilation

• Occurs in COPD clients with chronic hypoxemia and hypercarbia.

Nursing Actions

• Monitor respiratory rate, pattern, LOC, and SaO₂.

• Use the lowest effective oxygen flow rate.

• Prefer Venturi mask for precise FiO₂ if tolerated.

• Notify provider for signs of respiratory depression.

Combustion Risk

• Oxygen supports combustion.

Nursing Actions

• Post “No Smoking” or “Oxygen in Use” signs.

• Know location of fire extinguisher.

• Educate client and visitors about fire hazards.

• Use cotton gowns (reduce static electricity).

• Ensure electrical devices are functioning properly.

• Ensure equipment is grounded.

• Avoid flammable products near oxygen (alcohol, acetone).

Noninvasive Positive Pressure Ventilation

Continuous Positive Airway Pressure (CPAP)

• Provides continuous positive pressure via a leak-proof mask.

• Keeps airways open throughout the respiratory cycle.

• Improves alveolar gas exchange.

• First-line therapy for sleep apnea.

Bi-Level Positive Airway Pressure (BiPAP)

• Provides:

  • Higher inspiratory pressure

  • Lower expiratory pressure

• Requires a leak-proof mask.

• Commonly used in COPD requiring ventilatory assistance.

Nursing Actions

• Assess skin around mask for breakdown.

• Verify oxygen concentration and pressure settings.

Transtracheal Oxygen Therapy

• Delivers oxygen directly into the lungs via a small catheter inserted into the trachea.

• Less visible than nasal cannula.

• Reduces irritation from nasal prongs.

Endotracheal Tube and Endotracheal Intubation

Tube inserted through the mouth or nose into the trachea for emergency airway management.

Oral intubation

• Fastest and easiest method.

• Common in emergency settings.

Nasal intubation

• Used with facial or oral trauma.

• Contraindicated with clotting disorders.

Placement

• Performed by:

  • Nurse anesthetist

  • Anesthesiologist

  • Critical care or emergency physician

  • Pulmonologist

• Placement confirmation:

  • Chest x-ray (gold standard).

• ET tubes may be cuffed or uncuffed.

  • Inflated cuff forms a seal against the tracheal wall.

  • Prevents air leakage.

  • Ensures adequate tidal volume delivery.

• Client cannot speak when cuff is inflated.

Nursing Actions

• Keep manual resuscitation bag with face mask at bedside at all times.

• Limit intubation attempts to ≤30 seconds.

• Reoxygenate between attempts.

• Verify placement:

  • End-tidal CO₂

  • Chest x-ray

• Auscultate bilateral breath sounds.

• Observe for symmetrical chest rise.

• Secure tube with holder or tape.

• Monitor for hypoxemia, dysrhythmias, aspiration.

Mechanical Ventilation

Provides breathing support until lung function improves.

Delivers warmed, humidified oxygen.

FiO₂ range 21%–100%.

Positive-pressure ventilation keeps alveoli open and prevents collapse.

Benefits

• Forced lung expansion.

• Improved oxygenation.

• Decreased work of breathing.

Routes

• Endotracheal tube.

• Tracheostomy tube.

Ventilator Cycling

• Pressure

• Volume

• Time

• Flow

Indications

• Maintain patent airway and SaO₂ ≥95%.

Potential Diagnoses

• Hypoxemia

• Hypoventilation with respiratory acidosis

• Airway trauma

• COPD exacerbation

• Acute pulmonary edema (MI or heart failure)

• Asthma attack

• Head injury, stroke, coma

• Neuromuscular disorders (MS, myasthenia gravis, Guillain-Barré)

• Obstructive sleep apnea

• Postoperative respiratory support

• General anesthesia or heavy sedation

Mechanical Ventilation Considerations

Preparation of the Client

• Explain the procedure.

• Establish communication method:

  • Yes/no questions

  • Writing tools

  • Communication board

  • Lip reading

Ongoing Care

Airway Management

• Assess tube position and placement.

• Keep tubing free of condensation.

• Document tube depth at teeth or lips.

• Use two staff members to reposition tube.

• Use caution when moving the client.

Ventilation and Assessment

• Suction oral and tracheal secretions as needed.

• Support ventilator tubing to prevent erosion or displacement.

• Assess respiratory status every 1–2 hr:

  • Breath sounds

  • Symmetry

  • Respiratory effort

• Verify ventilator settings each shift and hourly:

  • Rate

  • FiO₂

  • Tidal volume

  • Mode

  • PEEP or CPAP

  • PIP or plateau pressure

  • Alarm limits

Ventilator Alarms

• Never turn off alarms.

• Volume (low pressure):

  • Disconnection

  • Cuff leak

  • Tube displacement

• Pressure (high pressure):

  • Secretions

  • Kinked tubing

  • Biting tube

  • Coughing

  • Pulmonary edema

  • Bronchospasm

  • Pneumothorax

• Apnea:

  • No spontaneous breaths detected.

Cuff Management

• Maintain minimal occlusive pressure.

• Check cuff pressure at least every 8 hr.

• Target <20 mm Hg or 20–30 cm H₂O.

• Signs of cuff leak:

  • Air hissing

  • Client vocalizing

  • Decreasing SaO₂

Medications

• Analgesics: morphine, fentanyl.

• Sedatives: propofol, diazepam, lorazepam, midazolam, haloperidol.

• Neuromuscular blockers:

  • Pancuronium

  • Atracurium

  • Vecuronium

  • Require sedation and analgesia.

• Ulcer prevention: famotidine, lansoprazole.

• Antibiotics as indicated.

Skin and Oral Care

• Reposition ET tube every 24 hr or per protocol.

• Provide oral care at least every 12 hr.

• Older adults require frequent gentle skin care.

Nutrition

• Assess GI function every 8 hr.

• Monitor bowel habits.

• Administer enteral or parenteral nutrition as prescribed.

Weaning Monitoring

• RR >30 or <8/min.

• HR or BP change >20% from baseline.

• SaO₂ <90%.

• Dysrhythmias or ST elevation.

• Decreased tidal volume.

• Increased work of breathing.

• Diaphoresis.

• Anxiety or decreased LOC.

Extubation Care

• Keep bag-mask and oxygen at bedside.

• Keep reintubation equipment available.

• Suction oropharynx and trachea.

• Deflate cuff and remove tube during peak inspiration.

• Monitor closely for airway obstruction:

  • Stridor

  • Dyspnea

  • Ineffective cough

• Monitor SpO₂ and vital signs every 5 min initially.

• Encourage coughing, deep breathing, incentive spirometry.

• Reposition frequently to mobilize secretions.

• Older adults need more frequent repositioning.

Mechanical Ventilation Complications

Trauma

• Barotrauma: pneumothorax, subcutaneous emphysema, pneumomediastinum.

• Volutrauma: lung damage from excessive volume.

Fluid Retention

• Caused by decreased cardiac output and RAAS activation.

• Monitor intake/output, weight, breath sounds, secretions.

Oxygen Toxicity

• Risk with FiO₂ >50% or prolonged therapy.

• Monitor for:

  • Fatigue

  • Restlessness

  • Severe dyspnea

  • Tachycardia

  • Tachypnea

  • Crackles

  • Cyanosis

Hemodynamic Compromise

• Increased intrathoracic pressure reduces venous return.

• Monitor for:

  • Hypotension

  • Tachycardia

  • Urine output ≤30 mL/hr

  • Cool, clammy skin

  • Decreased LOC

Aspiration

• Keep HOB ≥30° at all times.

• Check enteral feeding residuals every 4 hr.

Gastrointestinal Ulceration (Stress Ulcer)

• Monitor drainage and stool for occult blood.

• Administer ulcer prophylaxis.

Infection

• Related to intubation or suctioning.

• Monitor for:

  • Fever

  • Sputum changes

  • Crackles or rhonchi

  • Elevated WBCs

• Use strict aseptic technique during suctioning.

NCLEX Focus

Always confirm ET tube placement.

Alarms signal problems first, patient assessment comes first.

Bag the patient first if ventilator failure occurs.

Sedation does not equal pain control.

Keep HOB elevated to prevent aspiration.

Modes of Ventilation

Assist-Control Ventilation (AC)

• Preset respiratory rate and tidal volume.

• Client initiates a breath, ventilator delivers full preset breath.

• Ventilator can fully control ventilation in intubated clients.

• Risk of hyperventilation and respiratory alkalosis.

• Sedation may be required to reduce respiratory rate.

Synchronized Intermittent Mandatory Ventilation (SIMV)

• Preset respiratory rate and tidal volume for mandatory breaths.

• Client can initiate spontaneous breaths with variable tidal volume.

• Mandatory breaths are synchronized with client effort.

• Used as a primary mode or as a weaning mode.

• Allows more spontaneous ventilation than AC.

• Can increase work of breathing and cause respiratory muscle fatigue.

Inverse Ratio Ventilation (IRV)

• Prolongs inspiratory time to improve oxygenation.

• Used for severe hypoxemia refractory to PEEP.

• Often requires deep sedation or neuromuscular blockade.

• Risks include volutrauma and decreased cardiac output due to air trapping.

Airway Pressure Release Ventilation (APRV)

• Allows spontaneous breathing throughout the ventilatory cycle.

• Time-triggered and pressure-limited.

• Uses brief releases in pressure to allow exhalation.

• May reduce ventilator-induced lung injury.

• Fewer adverse cardiovascular effects compared with other modes.

Independent Lung Ventilation (ILV)

• Uses double-lumen endotracheal tube.

• Allows each lung to be ventilated separately.

• Indicated for unilateral lung disease.

• Requires two ventilators.

• Requires sedation and often neuromuscular blockade.

High-Frequency Ventilation

• Delivers very small tidal volumes at rapid rates (up to 3,000 cycles/min).

• Commonly used in pediatric or neonatal clients.

• Requires sedation and or neuromuscular blockade.

• Breath sounds are difficult to assess.

Adjunctive Therapies

Positive End-Expiratory Pressure (PEEP)

• Preset pressure applied at end of expiration.

• Added to ventilator settings to treat persistent hypoxemia.

• Keeps alveoli open and prevents collapse.

• Improves oxygenation by enhancing gas exchange.

• Typical range: 5–15 cm H₂O.

Weaning Modalities

Pressure Support Ventilation (PSV)

• Provides positive pressure during inspiration.

• Prevents alveolar collapse during expiration.

• Decreases work of breathing.

• Allows lower FiO₂ requirements.

• Can be used alone or with SIMV or AC.

• Typical setting: 5–20 cm H₂O.

• Pressures >20 cm H₂O increase risk of lung injury.

Continuous Positive Airway Pressure (CPAP)

• Delivers constant positive pressure during spontaneous breathing.

• Client breathes independently without set ventilator breaths.

• Often used with SIMV during weaning.

• Risks include volutrauma, decreased cardiac output, and increased intracranial pressure.

NCLEX Focus

• AC provides full ventilatory support.

• SIMV and PSV are common weaning modes.

• PEEP improves oxygenation but can reduce cardiac output.

• High pressures increase risk of barotrauma and hypotension.

• Always correlate ventilator mode with patient work of breathing and hemodynamic status.