Cardio

10/15/99

 

Restrictive Ds

• All interstial ds are restrictive
• All restrictive ds are not interstial
• ¯ Inhalation
• ¯ Compliance (lungs get bigger b/c filled w/trapped air)
• ¯ SaO2, ­ venous admixture

Obstructive

• ¯ Exhalation
• Surface tension leads to the collapse of lungs in exhalation
• ­ Compliance
• ¯ Recoil

• W/problem increase inspiration: expiration 1:4 (normal is 1:2)
• Usually push air out pursed lips
• This can use back pressure to open bronchioles
• When become O2 deprived, becomes 1:1—regular is 2%, 98% are fully oxygenated

 

La Place Law

 

• Residual volume—trapped air
• Ventilation—mechanical air in and out
• In asthma, emphysema and bronchitis does not have good ventilation
• The residual air is not good for gas exchange b/c full of CO2

 

Obstructed lung is poorly ventilated

• Becomes acidic b/c trapped CO2
• Vasoconstrict the areas w/increased CO2
• Innate's solution

1^st Solution—Changevaso breathing pattern (1:4 breathing pattern) decreased ratio

2^nd solution—vasoconstriction

COPD—developing cor pulmonale—hypertrophy of R side of heart

o       Get Right axis deviation

o       Pulmonary hypertension—edema

o       Blood gases will show ­ CO2 and ¯ O2

o       Acidosis—metabolic and respiratory

o       Diabetes and kidney failure cause metabolic acidosis

o       Acute metabolic acidosis—might benefit from artificial ventilation

o       Artificial ventilation causes damage

o       IPPB—intermittent positive pressure breathing

o       Drugs are also used

o       Bronchodilator

o       Can destroy alveolar walls

 

Restrictive

• No problem w/airway
• Interstitium will not work
• ¯ Compliance
• Lungs will not inflate
• ¯ Ventilation
• ¯ O2
• CO2 readily goes into the alveoli and builds
• End up w/the same situation
• Inverse relationship b/w compliance and recoil
• Tissues become hypoxic and need O2
• Increase the number of RBC's
• Do this w/the hope of increasing the amount of O2 to the area

3^rd Solution—Polycythemia—increase in number of RBC's

• If do not increase ventilation, only are sending more RBC's to an area
• Further ¯ SaO2
• Blood is getter thicker—runs risk of clotting
• Have RBC's w/decreased hemoglobin—reduced hemoglobin
• Pt starts looking blue
• Thicker blood makes the heart work harder

4^th solution--2-3DPG, ¯ affinity for CO2, makes it difficult to pick up O2, formed on RBC