Session 3 - Respiration

• What causes upper respiratory tract infections?

  viruses: influenza/other viruses

  bacterial: streptococcus A/pathogens
• pathphysiology of upper resp tract infections (URTIs)?

  1. pathogen enters body
  2. body elicits immune response
  3. releases WBC and inflammatory mediators (prostaglandins, histamine, bradykinin, leukotrienes) to kill foreign body
  4. this results in inflammation, increased capillary permeability and leakage, redness, swelling, pain
• 4 important lung volumes?

  Tidal volume, inspiratory reserve volume, expiratory reserve volume, residual volume.
• normal tidal volume?


  500ml-750ml
• normal inspiration reserve values?

  3L
• normal expiratory reserve values?

  1.5L
• normal total lung volume?

  6L for adult males, 4.5L for adult females
• what does V/Q stand for?

  Ventilation/Perfusion
• What is V/Q shunting?

  portion of pulmonary blood is shunted away from alveoli, resulting in ventilation without perfusion
• what is a V/Q mismatch?

  happens when part of lung receives oxygen without blood flow OR blood flow without oxygen
• what are the alveoli response for?

  Gas exchange. Where lung ands and blood exchange oxygen and carbon dioxide during inspiration and expiration
• what is end tidal capnography?

  measures amount of carbon dioxide
• is carbon dioxide is present, it means gas is being produced leading to some form of circulation through lungs and ability for diffusion into the alveoli to occur
• what are the primary indications for using end tidal capnography?

  monitoring respiratory status and confirming correct placement of endotracheal tube
• pulse oximetry measures the amount of oxygen attached to red blood cells
• gas exchange features:

  1. very thin
  2. moist lining
  3. good blood supply
  4. good ventilation
  5. large surface area
• pathophysiology of pleural effusion?

  Fluid accumulation in pleural space.

  Becomes noticeable at 300ml and can reach up to 1500ml
• what causes pleural effusion?

  1. changes in blood proteins leading to osmotic fluid shifting from cancer or liver disease
  2. Heart failure
  3. Trauma
• Signs and symptoms of pleural effusion?

  1. chest pain (esp when taking a deep breath)
  2. dry cough
  3. difficulty breathing (esp when taking deep breath/lying down)
  4. fever
  5. reduced breath sounds on auscultation
• You are providing bag/valve/mask positive pressure ventilation. What information can be sought to indicate when the patient is being hyperventilated?

  End tidal capnometry values are diminishing 
• Pleural effusions can be described as being?

  Frequently due to a change in blood proteins leading to osmotic fluid shifting 
• what is NOT a use for end tidal capnography?

  Detecting levels of carbon monoxide when poisoning is suspected
• A blood pH of 7.25 and a PaCO2 of 60mmHg is indicative of which of the following?

  Respiratory acidosis
• Which of the following is true of V/Q mismatch?

  To combat it, the body vasoconstricts blood vessels to poorly ventilating alveoli 
• Upper respiratory tract infections are almost always?

  Highly contagious and easily transmitted to others 
• End tidal capnography waveforms increasing in size can indicate which of the following?

  Rapid rise in body temperature