Critical Care Nursing A Holistic Approach Part 5.

Critical Care Nursing A Holistic Approach

Part 5

Anatomy and Physiology of the Respiratory System

Chapter 23

Copyright © 2005 Lippincott Williams & Wilkins. Instructor's Resource CD-ROM to Accompany Critical Care Nursing: A Holistic Approach, eighth edition.

ThoraxThorax

• Thoracic cage

– Ridged and flexible; protects organs

• Muscles of ventilation

– Diaphragm, external/internal intercostal muscles

• Lungs

• Pleural space

– Parietal pleura, visceral pleura

• Mediastinum

– Contains the heart, esophagus, vessels, thymus


Airways Airways

• Nasopharynx – warms, filters, and moisturizes

• Oropharynx

• Trachea – passageway, smooth muscle, cricoid cartilage

• Bronchi – right, left, carina (neuronal tissue)

• Bronchioles

• Terminal bronchioles

• Alveoli – gas exchange


Pulmonary CirculationPulmonary Circulation

• Deoxygenated blood from right ventricle

• Pulmonary artery – arteriole

• Capillaries

– Wrap around every alveoli

– Thin-walled for efficient gas exchange

• Venules

• Pulmonary vein

• Left atrium


Physiology of Respiration Physiology of Respiration

• Ventilation

– Movement of air between the alveoli and atmosphere

• Diffusion

– Movement of CO2 and O2 between alveoli and capillaries

• Transport

– Movement of O2 from the alveoli to the cells

– Movement of CO2 from the cells to the alveoli


Process of Ventilation Process of Ventilation

• Movement of the diaphragm

• Changes in the transpulmonary pressure

• Lung compliance

• Airway resistance


Balance of Ventilation to PerfusionBalance of Ventilation to Perfusion

• Alveolar dead space

– Collapsed alveoli from pneumonia or atelectasis

• Shunting

– Anatomical

• Blood moves from the right side to left side of the heart without being oxygenated

– Physiological

• Blood moved by alveoli without picking up oxygen


VQ Mismatch VQ Mismatch

• Physiological shunt

– Low ventilation–perfusion ratio

• Alveolar dead space

– High ventilation–perfusion ratio

• Silent unit

– Both ventilation and perfusion are decreased

Patient Assessment: Respiratory System

Chapter 24


HistoryHistory

• Dyspnea

• Chest pain

• Sputum production

• Cough

• Past history

• Family history

• Personal and social history


InspectionInspection

• Respiratory rate, depth, and pattern of respiration

• Labored breathing, use of accessory muscles

• Cyanosis of skin

• A/P diameter of chest, and patient posture

• Chest expansion

• Chest deformities or scars

• IE ratio

• Clubbing of the fingers


Palpation Palpation

• Tactile fremitus

• Subcutaneous emphysema

• Thoracic expansion

• Trachea


Percussion Percussion

• Audible vibrations

• Tactile vibrations


AuscultationAuscultation

• Tracheal breath sounds

– Over trachea, loud and harsh

• Bronchial breath sounds

– Over large airways they are normal; anywhere else they are not normal

• Bronchovesicular breath sounds

– Medium in pitch; heard over bronchioles

• Vesicular breath sounds

– Heard over distal airway; quiet, low pitched


Pulse Oximetry Pulse Oximetry

• Reflects the arterial oxygen saturation of hemoglobin

• Saturations of 93% to 99% are normal

• Not reliable in patients

– Using vasoconstricting meds

– With known dyshemoglobins (carboxyhemoglobin or methemoglobin)

– In shock, cardiac arrest

– With severe anemia


End-Tidal Carbon Dioxide MonitoringEnd-Tidal Carbon Dioxide Monitoring


Arterial Blood GasesArterial Blood Gases

• pH: 7.35–7.45

• PaO2: 80–100 mm Hg

• PaCO2: 35–45 mm Hg

• HCO3: 22–26 mm Hg

• SaO2: 93–99%


Acid–Base BalanceAcid–Base Balance

• Respiratory acidosis

• Respiratory alkalosis

• Metabolic acidosis

• Metabolic alkalosis


Other Diagnostic TestsOther Diagnostic Tests

• Chest X-ray

• Ventilation-perfusion scan

• Pulmonary angiogram

• Pulmonary function test (PFT)

• Bronchoscopy

• Thoracentesis

• Sputum culture

Patient Management: Respiratory System

Chapter 25


Pulmonary ToiletPulmonary Toilet

• Cough and deep breathing

• Chest physiotherapy

– Positioning

– “Good lung” down

– Postural drainage

– Percussion or vibration


Oxygen Delivery Systems Oxygen Delivery Systems

• Nasal cannula

– For children, blow-by

• Simple face mask

• Venturi mask

• Face tent

• Non-rebreather mask


Artificial AirwaysArtificial Airways

• Nasopharyngeal / Oropharyngeal

– Size by placing device from ear lobe to corner of mouth

• Endotracheal tube

– Uncuffed tubes for children younger than 10 years of age

• Laryngomask airway (LMA)

– Sizes 1,2,3,4, and 5

– Sizes 3 and 4 for most of the population

• Tracheostomies


Chest Tubes Chest Tubes

• Remove air and fluid from the pleural space

• Re-expand a collapsed lung

• Restore negative pressure to the pleural space


Reasons for a Chest Tube Reasons for a Chest Tube

• Hemothorax

• Pneumothorax

• Tension pneumothorax or hemothorax

• Fistula


Pharmacological Interventions Pharmacological Interventions

• Bronchodilators

• Anti-inflammatory agents

• Antibiotics

• Sedative agents


50/50 Rule of Respiratory Failure50/50 Rule of Respiratory Failure

• pH less than 7.25

• PaCO2 greater than 50 mm Hg

• PaO2 less than 50 mm Hg


Mechanical VentilatorsMechanical Ventilators

• Negative–pressure ventilator

• Positive–pressure ventilator

• Pressure ventilator

• High-frequency ventilator


Modes of Ventilation Modes of Ventilation

• Assist-control

• Synchronized intermittent mandatory ventilation (SIMV)

• Pressure-support

• Pressure-controlled ventilation

• Volume-guaranteed pressure option

• Continuous positive airway pressure (CPAP)

• Positive end-expiratory pressure (PEEP)


Ventilator Settings Ventilator Settings

• FiO2

• Respiratory rate

• Tidal volume

• Peak flow

• Pressure limit

• PEEP

• Sensitivity


Complications Complications

• Aspiration

• Barotrauma

• Ventilator–associated Pneumonia (VAP)

• Decreased cardiac output

Common Respiratory Disorders

Chapter 26


PneumoniaPneumonia

• Community-acquired pneumonia

• Hospital-acquired pneumonia

• Bacteria

• Viruses

• Mycoplasma

• Fungi

• Chemical


Pneumonia is an inflammatory response

to the uncontrolled multiplication of

microorganisms invading the lower respiratory tract.


PneumoniaPneumonia

• Studies

– CXR, sputum culture, bronchoalveolar lavage

• Management

– Antibiotics, oxygen, pulmonary toilet

• Supportive care

– Nutrition, hydration, rest

• Prevention

– Pneumococcal and influenza vaccines


Pleural EffusionPleural Effusion

• Accumulation of pleural fluid secondary to increased fluid formation

– Increased capillary permeability

– Deceased colloid osmotic pressure of the blood

– Increased intrapleural negative pressure

– Impaired lymphatic drainage

– Increased pressure in the capillaries or lymphatics


Assessment of Pleural Fluid Assessment of Pleural Fluid

• H/P finding

– Shortness of breath, chest pain

– Tachypnea, hypoxemia, pleural rub

• Diagnostic studies

– CXR – lateral decubitus

– Thoracentesis


Pneumothorax Pneumothorax

• Sudden onset of pleuritic chest pain

– Dyspnea, shortness of breath, increased work of breathing

• Diagnostic test

– CXR

• Management

– Oxygen

– Possible placement of chest tube


Pulmonary Embolism Pulmonary Embolism

• Part of a deep vein thrombosis that has traveled and lodged in the pulmonary arteries

• Severity depends on the extent of occlusion

• Mismatch of ventilation and perfusion

• Testing

– VQ scan or a pulmonary angiogram

• Management

– Anticoagulation


COPDCOPD

• History

– Exposure to risk factors, comorbidities, current medical treatment (beta blockers)

• Tests

– Spirometry, ABGs

• Management

– Oxygen, education, drug therapy, nutrition, exercise, surgical intervention


AsthmaAsthma

• A chronic inflammatory disease of the airways

• Airway hyperresponsiveness

• Variable airway obstruction

• Resolves spontaneously or after using a bronchodilator


AsthmaAsthma

• Testing

– Spirometry

– Pulmonary function testing

• Management

– Education, prevent exacerbation, optimize pharmacotherapy


Acute Respiratory FailureAcute Respiratory Failure

• A sudden and life–threatening deterioration in gas exchange

• Type I – Acute hypoxemic respiratory failure

• Type II - Acute hypercapnic respiratory failure

• Type III – Combined hypoxemic and hypercapnic failure


Acute Respiratory FailureAcute Respiratory Failure

• Tests

– ABGs, CXR, PFTs, CT, thoracentesis

• Management

– Correction of gases, oxygen therapy

– Reversal of any narcotics

– Possible mechanical ventilation

Acute Respiratory Distress Syndrome

Chapter 27


ARDSARDS

• Complex clinical syndrome

• Acute hypoxic injury

• Caused by direct or indirect pulmonary injury

– Direct injury - aspiration, pulmonary infection, near drowning, thoracic trauma or toxic inhalation

– Indirect injury – shock, sepsis, hypothermia, DIC, multiple transfusion eclampsia, pancreatitis, burns


Phases of ARDSPhases of ARDS


Diagnostic StudiesDiagnostic Studies

• Blood cultures

• Bronchoalveolar lavage – detection of interleukin-1 and tumor necrosis factor-

• Blood gas

• CXR

• Lung compliance, airway resistance, and pressure

Critical Care Nursing A Holistic Approach Part 5.

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Transcript of Critical Care Nursing A Holistic Approach Part 5.