Take a Deep Breath – Focus on the air- Where is it going? How does it move? What purpose does it serve?

Airway Defenses: Nose: Mucociliary clearance: Cough: Reflexive bronchoconstriction: Alveolar macrophages:

Ventilation Inhalation Exhalation

Rate and volume control: Respiratory control center in the brain stem Responds to chemoreceptors CO2, pH, O2 – all trigger responses Which would cause what?

Work of Breathing Lung Compliance: Ability of lung tissue and chest wall to expand Surfactant – key facilitator Chest injuries? What would they causes?

Work of Breathing Elastic recoil – Promotes expiration Elastin fibers are present around the alveoli which act just like an elastic Elastin fibers are damaged in patients with emphysema – leads to air trapping. What does this do for ventilation? Diffusion?

Work of Breathing Increased Airway Resistance: Asthma – results in bronchoconstriction, airway hyperreactivity, edema COPD – (emphysema) Most common cause is smoking – chronic inflammation leads to loss of elastic recoil. Cystic fibrosis – genetic – results in massive mucus production What impact do these have on ventilation?

Measuring ventilation Tidal volume Vital capacity Forced vital capacity Forced expiratory volume – 1 sec Residual volume Total lung capacity

Impaired ventilation Something interferes with the movement of air What might cause a narrowing or compression of the airways – anywhere along the way? What about neuronal stimuli – how might it be a cause of problems?

Diffusion Where alveoli interact with vascular – one cell thick! Diffusion – down the concentration gradient

Diffusion

Diffusion Enhanced by: Pressure – concentration gradient Solubility of gases: CO2 more soluble = diffuses more easily Distance from alveoli to capillary = super short Surface area What impact does accumulation of fluids have on the ability of gases to diffuse? What condition result in fluid accumulations?

PaCO2 – PaO2 – HbO2/saO2 Gases consist of particles – when they get in the serum they move about – this creates a pressure. How is this lab reported? The body can use this oxygen – it diffuses – Oxyhemoglobin = oxygen bound to hemoglobin The body cannot use this oxygen – Until it comes off the hemoglobin Hemoglobin is the delivery truck

Impaired diffusion Pressure/Solubility: O2 pressure Increases w/ Increased barometric pressures Temperature increases So – when would this decrease? High elevations Hypothermia Inadequate supply Membranes: Fluid or exudate = increased diffusion distance Decrease in surface area Fibrosis/thickening of either/both membranes

V/Q mismatch Either ventilation (V) or Perfusion (Q) is not adequate to facilitate gas exchange. No oxygen – but perfusion is present No perfusion – but oxygen is present

Results of decrease vent/diffusion Hypoxemia/hypoxia What is the end result? Brain is super sensitive – what will you see? Hypercapnia What PaCO2 values will you see? What type of acid/base imbalance do you have? What are some results of this?

Manifestation of impaired ventilation/diffusion Cough Excess mucus production Hemoptysis Dyspnea – subjective “patient reports…..” Accessory muscles use - objective Chest pain Barrel chest Adventitious breath sounds - objective

Systemic manifestations Cyanosis – late sign! ABG values What does ____________ tell you? PaCO2 PaO2 SaO2 Mental status – restless, irritable…..lethargy Finger clubbing

Pneumonia What does this do for: Ventilation? Diffusion? Red vs gray hepatization

COPD diseases Asthma, emphysema, chronic bronchitis

COPD diseases Asthma, emphysema, chronic bronchitis

COPD diseases Asthma, emphysema, chronic bronchitis

Acute respiratory distress syndrome

How does this impact ventilation/diffusion? Chest trauma Pneumothorax How does this impact ventilation/diffusion?

How does this impact ventilation? Chest trauma Flail chest How does this impact ventilation?

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