Cardio

10/18/99

 

¯V_a acinus

• Restrictive--¯ compliance, ­ recoil
• Obstructive
• ¯ S_a
• Saturation 95% is the expected value
• ¯ P_aO₂—hypoxemia
• Normal is 95mmHg
• ABG—arterial blood gas
• The assumption is that S_a and P_aO₂ are proportional
• In anemia, pressure would be down w/the saturation normal
• ­ PaCO2—hypercopnia--¯ pH
• Normal is 45mmHG
• ¯ pH leads to respiratory acidosis
• Atelectasis
• Collapse of the respiratory zone, esp. the acinus
• Resorptive—tissues is resorped
• Can't be ventilated, creates a vacuum, and collapses
• Mucus plug can block air,

 

 

 

 

           

Residual Volume

 

Expiratory

Reserve

Volume

 

 

Tidal

Volume

 

 

 

Inspiratory

Reserve

Volume

Lung Volumes

• Volumes make capacities
• There are four lung volumes
• Inspiratory reserve volume  (IRV)—the air that can brought in if you have to, can over inflate the lungs—normal volume in the adult male is 3000mL
• Tidal volume—the normal amount of air that is brought and out at normal quiet breathing—normal is 500mL
• Total inspiratory capacity—total air that is allow to be brought in to the lungs, this is a combination of inspiratory reserve + tidal volume =TIC this is about 3500mL
• Expiratory reserve volume—the air that can be forced out after normal tidal volume, can be gotten ride of 1100mL
• Residual volume—the air that can never be removed no matter what—1200mL—can't be ventilated
• Total lung capacity—is 5800mL in the adult male, ¯ 5-10% for a female, this is all four volumes put together—TLC = TV + ERV + RV + IRV
• Vital capacity—expiratory reserve + tidal volume + inspiratory reserve volume, this is the portion of the lungs that can be controlled—area that can be ventilated
• Functional residual capacity—expiratory reserve volume + residual volume
• ¯ V = ¯VC which is vital capacity—measured by spirometery
• Seen in both restrictive and obstructive ds
• Air doesn't go in and out—related to vital capacity
• Respiration goes down, O2 ¯, CO2 ­
• FVC—forced vital capacity
• Take a deep breath in and blow it all the way out
• How does VC go down?
• Obstruction
• Block the air way
• Mucus and bronchoconstriction
• Air can get passed through the negative pressure
• It cannot exhale (this is passive)
• Residual capacity is on the rise b/c air is trapped
• One solution—expand the area of vital capacity—make the lungs bigger
• Barrel chest
• Gets to large—have to start using muscles to exhale
• Residual volume continues to grow and VC still decreases
• FEV₁—force expiratory volume for 1 sec
• A timed volume
• 80% of air can be removed in the first second
• This will only happen if the airways are open
• In obstructive ds, this will be greatly down
• Normal HCO3 is 21 milliparts
• Dyspnea (Shortness of Breath)—is not related to chemicals put to mechanics
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