Cardio

10/11/99

 

Respiratory Physiology

• Going to be looking at volumes and capacities
• Classification of obstructive and restrictive
• Obstructive ds

1.      Bronchitis

2.      Asthma

3.      Emphysema

• Restrictive ds
• Pneumothorax
• Cancer
• Pneumonia—rapid shallow breathing
• Pleural effusion
• Pulmonary fibrosis
• The ds that links the two is cystic fibrosis—more obstructive than restrictive
• Difference b/w obstructive and restrictive
• Obstructive means airway ds
• Often use dis-ease (except for emphysema)
• Restrictive is interstitial
• Interstitium is the area b/w the epithelial layer of the alveoli and the endothelial layer of the capillaries—this is where gas exchange occurs
• Fever w/an upper respiratory condition leads to pneumonia
• Hypoxemia—deficient O2 in the blood
• Take a blood gas
• O2 levels are decreasing
• Concerned w/O2 and CO2
• ABG—arterial blood gas
• Hypercapnia—CO2
• Levels are on the rise
• May lead to respiratory acidosis if it is not taken care of
• Pt can be a little low in O2 before the CO2 will start increasing
• Getting rid of CO2 is for pH control
• Respiratory failure—decreased O2 and increased CO2
• In the long term, the pt's kidneys will try to compensate for the acidosis w/carbonate
• For example in a COPD pt, will have low O2, high CO2 and high bicarbonate
• SaO2—saturation of O2 on the RBC in a % (does not directly measure O2 or CO2)
• PaO2—arterial pressure of O2
• PaO2 may be low even if SaO2 is normal—anemia
• SaO2 decreased and PaO2 normal at 95mmHg—leads to polycythemia as a solution—occurs b/c of the lung disorder

 

V/Q

• V=ventilation
• Q=perfusion (or blood)
• In order to sustain life, have to have air and blood in the same place at the same time
• V/Q imbalance is when the air and blood are not in the same place together
• Ventilation is the
• Perfusion—pumping of the blood
• Look at blood gas and saturation levels
• If ­SaO2, then ­ PaO2—assumed until blood gases are performed
• Restrictive lung ds leads to trouble inflating lungs
• Scoliosis is restrictive lung ds (trouble inflating lungs)
• Pulmonary embolism—low Q
• Figure from library
• Ad is alveolar ducts
• As is alveolar sacs
• Trachea
• BR—bronchi
• BL—bronchioloes
• TBL—terminal bronchioles
• RBL—respiratory bronchioles
• Conducting Zone—no gas exchange
• Trachea
• Bronchi
• Bronchioles
• Terminal bronchioles
• Transit and Respiratory zone—where gas exchange takes place
• Respiratory bronchioles
• Alveolar ducts
• Alveolar sacs
• Asthma affects this area esp. at respiratory zone
• Emphysema
• Why these ds have changes in blood gases
• Acinus—same as the respiratory zone