Meccanismi di difesa dell’apparato respiratorio


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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



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




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