bled ppt ch27 part01

Copyright 2006 © Pearson Education Canada 27:1-1

Chapter 27, Part 1

Pathophysiology and Respiratory

Disorders


Lecture Outline

Introduction Physiology review Pathophysiology Assessment Management Specific respiratory diseases


Introduction

More than 20 000 people die each year due to respiratory complaints

Intrinsic factors Heredity

Extrinsic factors Smoking Environmental pollutants


Physiologic Processes Gas exchange

The process by which oxygen is taken in and carbon dioxide is eliminated Ventilation Diffusion Perfusion


Ventilation Mechanical process of moving air

in and out of the lungs Requires body structures to be

intact Inspiration

Air drawn into lungs

Expiration Air leaves the lungs


Body Structures for Ventilation


Inspiration


Expiration


Diffusion Process by which gases move

between alveoli and pulmonary capillaries

Gases flow from areas of high to low concentration

O2 and CO2 Move across the membrane according to

their concentration gradients


Diffusion Respiratory membrane must remain

intact Affected by

Disease process that damage alveoli Fluid accumulation in interstitial space Diseases that cause thickening of the endothelial

lining Oxygen therapy

Improves concentration gradient Medications

Address inflammation and fluid accumulation


Lung Perfusion Circulation of blood through the

pulmonary capillaries Effective perfusion

Adequate lung volume Adequate concentration of hemoglobin

Oxygen transport 2% in solution 98% bound to hemoglobin


Hemoglobin

Four iron heme and one protein globin molecules

Oxygen binds to heme molecule As oxygen binds

More readily accepts additional oxygen molecules

Relationship described in oxygen dissociation curve


Oxygen Dissociation Curve


Oxygen Dissociation Curve

Alterations Temperature Blood pH Carbon dioxide partial pressure

Allows for oxygen to be released at tissues and bound at lungs


Carbon Dioxide Majority transported as bicarbonate

ions Transported in red blood cells and released at

lungs

Rest transported Bound to hemoglobin Dissolved in plasma

Haldane effect As heme is saturated with O2, more CO2 is

released


Disruption in Ventilation Upper and lower respiratory tracts

Obstruction due to trauma or infectious processes

Chest wall and diaphragm Trauma Neuromuscular disease

Nervous System Trauma Poisoning or overdose Disease


Abnormal Respiratory Patterns

Cheyne-Stokes respirations Progressively increasing then declining

respiration, separated by period of apnea Terminal illness or brain injury

Kussmaul’s respirations Deep rapid breaths Corrective measure for metabolic acidosis

Central neurogenic hyperventilation Deep, rapid respirations Stroke or injury to brainstem



Ataxic (Biot’s) respirations Repeated episodes of gasping separated by

apnea Increased intracranial pressure

Apneustic respirations Long deep breaths, stopped during inspiratory

phase Separated by periods of apnea Stroke or severe central nervous system disease


Pathophysiology

Disruption in diffusion Hypoxia Damaged alveoli

Disruption in perfusion Alteration in blood flow Alterations in hemoglobin Pulmonary shunting


Assessment

Scene assessment Safety BSI Identify rescue environments having

decreased oxygen levels Gases and other chemical or biological agents

Clues to patient information


General Impression of the Patient

Position Color Mental status Ability to speak Respiratory effort


Signs of Respiratory Distress

Nasal flaring Intercostal retraction Use of accessory muscles Cyanosis Pursed lips Tracheal tugging


Airway Noisy breathing means partial airway

obstruction Obstructed breathing is not always noisy Brain can only survive minutes in asphyxia Ventilation is useless if the airway is blocked A patent airway is useless if the patient is

apneic Act on airway obstruction


Breathing Signs of life-threatening problems

Alterations in mental status Severe central cyanosis, pallor, or

diaphoresis Absent or abnormal breath sounds Speaking limited to 1–2 words Tachycardia Use of accessory muscles or presence of

retractions


History SAMPLE History OPQRST History

Paroxysmal nocturnal dyspnea and orthopnea

Coughing and hemoptysis Associated chest pain Smoking history or exposure to

secondary smoke

Similar Past Episodes


Physical Examination Neck

Swelling JVD

Inspection Symmetry/asymmetry Increased diameter Paradoxical motion Scars, lesions, wounds, deformities

Palpation Tenderness Subcutaneous emphysema Tracheal deviation Tactile fremitus


Auscultation Normal breath sounds

Bronchial Bronchovesicular Vesicular

Abnormal breath sounds Snoring Stridor Wheezing Rhonchi Crackles Pleural friction rub


Extremities Peripheral cyanosis Swelling and redness, indicative of a venous clot Finger clubbing, which indicates chronic

hypoxia.


Vital Signs Heart Rate

Tachycardia

Blood pressure Pulsus paradoxus

Respiratory rate Observe for trends Assume as elevated rate is caused by hypoxia Assume a slow rate is impending respiratory

arrest


Pulse Oximetry

Offers rapid and accurate measure of oxygen saturation

Difficult or inaccurate Peripheral vasoconstriction

Hypothermia Sepsis

Carbon monoxide Hypovolemia


Sensing unit for pulse oximetry


Peak Flow Handheld device for

determining patient peak expiratory flow rate


Capnometry Continuous waveform or colorimetric Detect carbon dioxide at end of expiration Roughly equal to partial pressure in blood Reflects adequacy of ventilations


Management Principles Maintain the airway

Protect the cervical spine if trauma is suspected

Any patient with respiratory distress should receive oxygen

Any patient suspected of being hypoxic should receive oxygen

Oxygen should never be withheld from a patient suspected of suffering from hypoxia.


Upper-Airway Obstruction Common Causes

Tongue, foreign matter, trauma, burns Allergic reaction, infection

Assessment Differentiate cause

Conscious patient If the patient is able to speak, encourage

coughing If the patient is unable to speak, perform

abdominal thrusts


Upper-Airway Obstruction Unconscious Patient

Open the airway Attempt to give two ventilations

If they fail, reposition the head and reattempt Administer abdominal thrusts Attempt finger sweeps if foreign body is

visualized If foreign body is removed, resume ventilation If unsuccessful, continue abdominal thrusts and

sweeps Visualize the airway with the laryngoscope

Remove foreign body with Magill forceps and resume ventilations


Adult Respiratory Distress Syndrome

Disorder of lung diffusion Inability to maintain proper fluid

balance in interstitial space Disruption of alveolar-capillary

membrane Non-cardiogenic pulmonary edema High mortality



Sepsis Aspiration Pneumonia Pulmonary Injury Burns/Inhalation Injury Oxygen Toxicity Drugs High Altitude Hypothermia

Near-Drowning Syndrome Head Injury Pulmonary Emboli Tumor Destruction Pancreatitis Invasive Procedures

Bypass, hemodialysis Hypoxia, Hypotension, or

Cardiac Arrest



Manage the underlying condition Provide supplemental oxygen Support respiratory effort

Provide positive pressure ventilation if respiratory failure is imminent

Monitor cardiac rhythm and vital signs Consider medications

Corticosteroids


Obstructive Lung Diseases Widespread in society

Abnormal ventilation Some elements may be reversible

Asthma Chronic Obstructive Pulmonary

Disease Chronic bronchitis Emphysema


Emphysema

Destruction of alveolar walls distal to the terminal bronchioles

Contributing factors Heredity Cigarette smoking Environmental factors


Pathophysiology Destruction of alveolar surfaces

Decreased area for gas exchange Hypoxia

Cor pulmonale Decreased number of pulmonary capillaries Hypoxia constricts pulmonary vessels Increased resistance to right cardiac output Right heart failure


Cor Pulmonale


Pathophysiology Weakening of alveolar walls

Loss of elastic recoil Air trapping Pursed lipped breathing Barrel chest

Unable to expel carbon dioxide Chronic increased respiratory rate and accessory

muscle use SOBOE Polycythemia


Assessment History

Recent weight loss, dyspnea with exertion Cigarette and tobacco usage Lack of cough

Physical Exam Barrel chest Prolonged expiration and rapid rest phase Thin Pink skin due to extra red cell production Hypertrophy of accessory muscles “Pink Puffers


Chronic Bronchitis

Increased number of goblet cells in the respiratory tree

Production of large quantity of sputum

Often occurs after prolonged exposure to cigarette smoke


Pathophysiology

Alveoli not severely affected Gas exchange is compromised

Decreased alveolar ventilation

Hypoxia Pulmonary vasoconstriction Cor pulmonale

Vital capacity is decreased


Chronic mucous production and plugging of the airways


Assessment History

Frequent respiratory infections Productive cough

Physical Assessment Often overweight Rhonchi present on auscultation Jugular vein distention Ankle edema Hepatic congestion “Blue Bloater.”


Management For both emphysema and chronic

bronchitis Relieve hypoxia

Maintain airway Support breathing

Find position of comfort Monitor oxygen saturation Be prepared to ventilate or intubate

Reverse bronchoconstriction Bronchodilators


Asthma

Chronic inflammatory disorder of the airways

Approximately 20 children and 500 adults die each year

50% die before reaching hospital Most deaths could be prevented

with education


Pathophysiology Inflammation causes widespread

variable airflow obstruction Airways become hyperresponsive

Induced by a trigger (varies by individual) Release of histamine Bronchoconstriction and bronchial edema 6–8 hours later, immune system cells

invade the bronchial mucosa Additional edema.


Assessment Identify immediate threats History

SAMPLE & OPQRST History History of asthma-related hospitalization History of respiratory failure/ventilator use

Physical Exam Presenting signs may include dyspnea, wheezing, cough

Wheezing is not present in all asthmatics Speech may be limited to 1–2 consecutive words

Hyperinflation of the chest and accessory muscle use Carefully auscultate breath sounds and measure peak

expiratory flow rate.


Management Treatment goals:

Correct hypoxia Reverse bronchospasm Reduce inflammation

Maintain the airway Support breathing

High-flow oxygen or assisted ventilations as indicated Monitor cardiac rhythm Establish IV access Administer medications

Beta-agonists Ipratropium bromide Corticosteroids


Special Cases of Asthma Status Asthmaticus

A severe, prolonged attack that cannot be broken by bronchodilators

Greatly diminished breath sounds Recognize imminent respiratory arrest

Aggressively manage airway and breathing Transport immediately

Asthma in Children Pathophysiology and management similar Adjust medication dosages as needed


Upper Respiratory Infection Upper Respiratory Infections (URIs)

Frequent patient complaint Common pediatric complaint Rarely life threatening

Pathophysiology Frequently caused by viral and bacterial

infections Affect multiple parts of the upper airway Typically resolve after several days of symptoms


Upper Respiratory Infection

Assessment Look for underlying illness Evaluate pediatrics for epiglottitis

Management Maintain the airway Support breathing Treat signs and symptoms


Pneumonia

Infection of the lungs Particularly dangerous in immune-

suppressed patients

Usually a bacterial or viral infection Spreads to other parts of lung Fluid and inflammatory cells collect Disorder of ventilation May spread to entire lung


Assessment

Focused history and physical exam SAMPLE & OPQRST

Recent fever, chills, weakness, and malaise Deep, productive cough with associated pain

Tachypnea and tachycardia may be present Breath sounds

Presence of rales/crackles in affected lung segments

Decreased air movement in the affected lung


Management Maintain the airway Support breathing

High-flow oxygen or assisted ventilation as indicated

Monitor vital signs Establish IV access

Avoid fluid overload

Medications Antibiotics, antipyretics, beta-agonists


Lung Cancer

Leading cause of cancer death among men and women

Linked to cigarette smoking and environmental pollutants

Causes: Spread from somewhere else in the body Carcinogen


Lung Cancer Types

Adenocarcinoma Epidermoid Small-cell, and large-cell carcinomas

Assessment Focused history and physical exam

SAMPLE & OPQRST History• Cancer-related treatments and hospitalizations

Physical Exam• Evaluate for severe respiratory distress


Lung Cancer

Management Administer oxygen Support ventilation Be aware of any DNR order Provide emotional support


Toxic Inhalation Pathophysiology

Includes inhalation of heated air, chemical irritants, and steam

Airway obstruction due to edema Laryngospasm due to thermal and chemical

burns

Assessment Focused history and physical exam

SAMPLE & OPQRST History• Determine nature of substance.• Length of exposure and loss of consciousness


Toxic Inhalation Ensure scene safety

Enter a scene only if properly trained and equipped

Remove the patient from the toxic environment

Maintain the airway Early, aggressive management may be indicated

Support breathing Establish IV access Transport promptly.


Carbon Monoxide Odorless, colourless gas

Results from the incomplete combustion Often builds up to dangerous levels in

confined spaces Hazardous to Rescuers

Pathophysiology Binds to hemoglobin Prevents oxygen from binding and

creates hypoxia at the cellular level.


Carbon Monoxide

Assessment Determine source and length of exposure Headache Confusion Agitation Lack of coordination, Loss of consciousness Seizures


Management Ensure the safety of rescue personnel Remove the patient from the exposure

site Maintain an open airway Provide high-concentration oxygen Consider transport to hyperbaric

chamber


Pulmonary Embolism Pathophysiology

Obstruction of a pulmonary arteryEmboli may be of air, thrombus, fat, or amniotic fluidForeign bodies may also cause an embolus

Risk FactorsRecent surgery, long-bone fractures, pregnancyPregnant or postpartumOral contraceptive use, tobacco use


Assessment Focused history and physical exam SAMPLE and OPQRST History

Presence of risk factors Sudden onset of severe dyspnea and pain Cough, often blood-tinged

Physical Exam Signs of heart failure, including JVD and

hypotension Warm, swollen extremities (DVT)


Management Maintain the airway Support breathing

High-flow oxygen or assist ventilations as indicated

Intubation may be indicated

Establish IV access Monitor vital signs closely Transport to appropriate facility


Spontaneous Pneumothorax

Occurs in absence of trauma Risk factors

Rare but high recurrence rate More males than females (5:1) Tall, thin stature Between 20 and 40 years COPD (ruptured bleb)


Spontaneous Pneumothorax

Pathophysiology Disease of ventilation Pneumothorax occupying 15-20% of chest

cavity generally well tolerated

Assessment Presence of risk factors Rapid onset of symptoms Sharp, pleuritic chest or shoulder pain Often precipitated by coughing or lifting


Management

Maintain the airway Support breathing Monitor for tension pneumothorax Pleural decompression JVD Tracheal deviation away from the

affected side.


Hyperventilation Syndrome

Characterized by rapid breathing Chest pains Numbness Other symptoms associated with anxiety

Many serious diseases cause hyperventilation Consider it to be an indicator of a serious

medical condition



Assessment SAMPLE & OPQRST history

Fatigue, nervousness, dizziness, dyspnea, chest pain

Numbness and tingling in hands, mouth, and feet

Presence of tachypnea and tachycardia Spasms of the fingers and feet.



Management Maintain the airway Support breathing Provide high-flow oxygen or assist

ventilations as indicated Do not allow the patient to rebreathe

exhaled air Reassure the patient


CNS Dysfunction Pathophysiology

Traumatic/atraumatic brain injury Tumours Drugs

Assessment Evaluate potentially treatable causes

Narcotic drug overdose CNS trauma.

Carefully evaluate breathing pattern.


Pathophysiology PNS problems affecting respiratory function

Trauma Polio Myasthenia gravis Viral infections Tumours

Assessment Rule out traumatic injury, and assess for

numbness, pain, or signs of PNS dysfunction.

Dysfunction of the Spinal Cord, Nerves, or

Respiratory Muscles


Management

Follow general management principles.

Maintain the airway and support breathing.

Use cervical spine precautions if indicated.


Summary

Review of Respiratory Physiology Pathophysiology Assessment Management Specific Respiratory Diseases

bled ppt ch27 part01

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