Meccanismi di difesa dell’apparato respiratorio

Prof. Carlo Vancheri Cattedra di Malattie dell’Apparato Respiratorio Ex Istituto di Malattie dell’Apparato Respiratorio – Via Passo Gravina 187, Catania Ospedale Tomaselli

Meccanismi di difesa dell’apparato respiratorio

Anatomy of the Cough Reflex

Cough Mechanics

• Inspiratory Phase

• Glottis reflexly opens

• Deep inspiration to a high lung volume > FRC

• This allows the optimisation of length tension relationships of expiratory muscles

• Higher expiratory pressures and flows can thus be generated

Cough Mechanics

• Compressive Phase

• Characterised by glottic closure and near simultaneous onset of expiratory muscles in the rib cage and abdomen

• High intrathoracic pressures are generated up to 300 cm H20

• These pressures are 50-100% > than that obtained during other forced expiratory manoeuvres, and permits generation of flow rates needed for an effective cough

Cough Mechanics

• Expiratory Phase

• Glottis opens after 0.2 sec, and high expiratory flow rates up to 15 l/sec are generated

• Associated passive oscillations of tissue and gas

• Rapid fall in central airway pressure, and sustained high intra-alveolar and intrapleural pressures allow high gas velocities up to Mach 0.6

• High kinetic energy, fluid shear forces and wall accelerations are important in suspending and accelerating secretions which are adherent to the bronchial walls towards the mouth

Respiratory Presentations

• Acute breathlessness

• Chronic breathlessness

• Cough

• Sputum

• Haemoptysis

• Chest pain

Respiratory Presentations

• Acute breathlessness

• Chronic breathlessness

• Cough

• Sputum

• Haemoptysis

• Chest pain

Characteristics of Normal Breathing

• Normal rate and depth

• Regular breathing pattern

• Good breath sounds on both sides

• Equal rise and fall of chest

• Movement of the abdomen

Signs of Abnormal Breathing

• Rate < 8 or > 24 breaths/min

• Muscle retractions

• Cool, damp (clammy), and pale or blue skin

• Shallow or irregular respirations

• Pursed lips

• Nasal flaring

Causes of Dyspnea

• Upper or lower airway infection

• Infectious diseases may affect all parts of airway.
• Usually some form of obstruction to air flow or the exchange of gases

• Acute pulmonary edema

• Fluid build-up in the lungs

Causes of Dyspnea

• Chronic obstructive pulmonary disease (COPD)

• Result of direct lung and airway damage from repeated infections or inhalation of toxic agents
• Bronchitis and emphysema are two common types of COPD.

Causes of Dyspnea

• Spontaneous pneumothorax

• Accumulation of air in the pleural space

• Asthma or allergic reactions

• Either can result in acute spasms of the bronchioles.

• Pleural effusion

• Collection of fluid outside lung

Causes of Dyspnea

• Mechanical obstruction of the airway

• Obstruction may result from the tongue, aspiration, vomitus, or foreign body.

• Pulmonary embolism

• Blood clot in pulmonary circulation

Dispnea polmonare e cardiaca

• DP acuta:polmonite,pneumotorace,asma, corpi estranei

• DP insorgenza attenuata ma in rapida progressione:vers. Pleurici,tumori, TBC

• DP a lenta progressione: BPCO, interstiziopatie

• DC acuta: tromboembolia polmonare, edema polmonare

• DC a rapida progressione: tromboembolia polm. Ricorrente, insufficienza cardiaca congestizia

Respiratory Presentations

• Acute breathlessness

• Chronic breathlessness

• Cough

• Sputum

• Haemoptysis

• Chest pain

Cough - features

• Duration

• Frequency

• Productive/non-productive

• Pleurisy

Cough - features

• Duration

• Frequency

• Productive/non-productive

• Pleurisy

Cough - diagnostic aspects

• Duration

• If recent onset, more likely new diagnosis
• bronchial carcinoma, acute infection
• If long-standing, more chronic condition likely
• chronic bronchitis, bronchiectasis

Cough - features

• Duration

• Frequency

• Productive/non-productive

• Pleurisy

Cough - diagnostic aspects

• Frequency (I)

• Predominantly nocturnal
• asthma, LVF
• Daily, especially in mornings
• chronic bronchitis
• Daily, affected by posture
• bronchiectasis

Cough - diagnostic aspects

• Frequency (II)

• Sudden onset
• inhaled foreign body
• Exacerbated by swallowing
• aspiration

Cough - features

• Duration

• Frequency

• Productive/non-productive

• Pleurisy

Cough - diagnostic aspects

• Productive/non-productive

• Productive
• chronic bronchitis, bronchiectasis, lung abscess
• Non-productive
• asthma, laryngitis, tracheitis, bronchial carcinoma, early acute bronchitis or pneumonia

Cough - features

• Duration

• Frequency

• Productive/non-productive

• Pleurisy

Cough - diagnostic aspects

• Pleurisy

• Associated with pleuritic pain
• pneumonia, bronchial carcinoma, pneumothorax
• Less likely to be associated with pleuritic pain (distinguish from muscoloskeletal pain)
• acute and chronic bronchitis, asthma, LVF, laryngitis, tracheitis,
• (cough fractures)

Cough as a symptom of Asthma

• Cough as the only symptom of asthma occurs in 6.5% to 57.0% of patients

• Termed “Cough Variant Asthma”

• Defined as “Cough as the only symptom of asthma in patients with demonstrable airway hyperresponsiveness” Johnson et al, J Asthma 1991

• Definitive diagnosis is only made when cough resolves with specific asthma medications

ACE-I Cough

• Peptidase inhibition

• Bradikinin rising stimulates the cough’s reflex nerves

Chronic Persistent Cough

• Cough for at least 3 weeks

• Cough being the only presenting symptom

• Cough is not associated with haemoptysis

• The absence of prior history of chronic respiratory disease to account for the cough

• Current Chest X-ray does not contribute to the diagnosis

• Cough may be with or without sputum production

Causes of Chronic Cough

Respiratory Presentations

• Acute breathlessness

• Chronic breathlessness

• Cough

• Sputum

• Haemoptysis

• Chest pain

Sputum - features

• Amount

• Character

• Taste/Odour

Sputum - features

• Amount

• Character

• Taste/Odour

Sputum - diagnostic aspects

• Amount

• Only rarely accurately assessed by patient
• Not usually diagnostically useful to know precise quantity!
• Large volumes of sputum suggest certain conditions:
• bronchiectasis, lung abscess, chronic bronchitis

Sputum - features

• Amount

• Character

• Taste/Odour

Sputum - diagnostic aspects

• Character (I)

• Thin/serous/frothy
• LVF (pink), hysterical (saliva)
• Mucoid, grey/white/clear
• Chronic bronchitis

Sputum - diagnostic aspects

• Character (II)

• Mucoid, yellow
• Chronic bronchitis, asthma
• Mucoid, green
• Bacterial infection e.g. acute bronchitis, bronchiectasis, pneumonia, lung abscess

Sputum - features

• Amount

• Character

• Taste/Odour

Sputum - diagnostic aspects

• Taste/Odour

• Muco-purulent sputum
• Bacterial infection e.g. acute bronchitis, bronchiectasis, pneumonia, lung abscess
• Highly offensive and putrid
• anaerobic infection e.g. lung abscess, bronchiectasis

Respiratory Presentations

• Acute breathlessness

• Chronic breathlessness

• Cough

• Sputum

• Haemoptysis

• Chest pain

Definition

• Expectoration of blood from the respiratory tract

• Varies from blood streaking of sputum to coughing up massive amounts of blood

• Very frightening to the patient and to the treating physician especially when acute

Definition

• Assessment of severity of hemoptysis can be based on amount of blood lost during episode

• Mild: Less than 60 cc of blood lost for the whole episode

• Massive: More than 100 cc to 600cc of blood lost in a 24 hour period

• Life-threatening: More than 120 cc of blood lost in an hour

Where is it from??

Where is it from??

• Upper airway bleeding can only be excluded by a good ENT examination

• Blood from the upper GIT can be aspirated and coughed up

• Blood from the lungs can be swallowed and vomited

Significance

• Hemoptysis is an important sign of an underlying disease

• Massive hemoptysis is life threatening due to Asphyxia

• Mortality rate can be as high as 80%

Etiology

• Source other than the lower respiratory tract

• Upper airway (nasopharyngeal) bleeding
• Gastrointestinal bleeding

• Tracheobronchial source

• Neoplasm (bronchogenic carcinoma, endobronchial metastatic tumor, Kaposi's sarcoma, bronchial carcinoid)
• Bronchitis (acute or chronic)
• Bronchiectasis
• Airway trauma
• Foreign body

Etiology

• Pulmonary parenchymal source

• Lung abscess
• Pneumonia
• Tuberculosis
• Mycetoma ("fungus ball")
• Goodpasture's syndrome
• Idiopathic pulmonary hemosiderosis
• Wegener's granulomatosis
• Lupus pneumonitis
• Lung contusion

Etiology

• Primary vascular source

• Arteriovenous malformation
• Pulmonary embolism
• Elevated pulmonary venous pressure (esp. mitral stenosis)
• Pulmonary artery rupture secondary to balloon-tip pulmonary artery catheter manipulation

• Miscellaneous/rare causes

• Pulmonary endometriosis
• Systemic coagulopathy or use of anticoagulants or thrombolytic agents

Causes of Massive Hemoptysis

• Tuberculosis

• Bronchiectasis

• Fungal Infections

• Other Lung Infection

• Bronchogenic Carcinoma

• Chemotherapy and Bone Marrow Transplantation

• Immunologic Lung Disease

• Cardiac or Vascular Disease

Diagnostic Approach

• Patient’s with massive hemoptysis need rapid establishment of airway patency, prevention of suffocation and control of bleeding

• The secondary goal is to determine the site of bleeding and cause

BPCO TBC CA

• 4,4 94.4 0.2 (1932)

• 24.3 72,7 3 (1960)

• 33,6 20.8 45.6 (1980)

History and Physical

• History, physical examination, and chest x-ray are not very reliable but important

• Important points in the history:

• Hx of prior lung, cardiac or renal disease
• Hx of smoking
• Hx of prior hemoptysis, pulmonary symptoms or infectious symptoms
• Family history of hemoptysis
• Skin rash

History and Physical

• Hx of exposure to organic chemicals
• Travel history
• Hx of exposure to asbestos
• Hx of bleeding disorders, use of aspirin or NSAIDS, or anticoagulants
• Upper airway or upper GI symptoms

Respiratory Presentations

• Acute breathlessness

• Chronic breathlessness

• Cough

• Sputum

• Haemoptysis

• Chest pain

Chest pain - features

• Pleuritic (worse on inspiration and coughing)

• Onset

• Other diagnoses

Chest pain - features

• Pleuritic (worse on inspiration and coughing)

• Onset

• Other diagnoses

Chest pain - diagnostic aspects

• Pleuritic pain

• Due to stretching of inflamed parietal pleura
• Needs to be distinguished from cardiac pain and GOR and spasm
• Pneumonia, PE, pneumothorax, rib fractures, tumours

Chest pain - features

• Pleuritic (worse on inspiration and coughing)

• Onset

• Other diagnoses

Chest pain - diagnostic aspects

• Onset

• Sudden onset
• pneumothorax, PE, rib fracture
• acute pneumonia can cause sudden onset pain
• Gradual onset, dull dragging chest pain initially becoming more acute, may be associated breathlessness if pleural effusion
• malignancy, primary (mesothelioma) or secondary

Chest pain - features

• Pleuritic (worse on inspiration and coughing)

• Onset

• Other diagnoses

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Laboratory Evaluation

• CBC with differentials

• Electrolytes, BUN, and Creatinine

• Liver functions

• PT, PTT

• Urinalysis

• ABG

• Drug levels when suspected

• Blood grouping and cross matching

• Sputum stain and culture for M. Tuberculosis and Fungi

• Cytology

• Bedside Spirometry to assess the fitness of the patient for surgery

Initial Management

• The patient should be monitored in an ICU setting

• Early pulmonology and thoracic surgery consultation

• If bleeding decreases and patient stabilized, mild sedation and cough suppression

Initial Management

• If the bleeding site is known, the patient should be put in a lateral decubitus position with the bleeding side down to protect the other lung from spillage and drowning

• If oxygenation is compromised or bleeding continues, the patient should be intubated

Diagnostic Procedures

• Bronchoscopy

Bronchoscopy

Other Diagnostic Procedures

• Arteriography

• CT Scan of the Chest

• NEVER MOVE AN UNSTABLE PATIENT FROM THE ICU FOR THE SAKE OF DOING A CT

• Other less important and less yielding test such radionuecleotide studies

CT Scan

Diagnostic Approach for Non Massive Hemoptysis