finition: TLC decreased by 20% compared to predict lues based on height, age, gender RESTRICTIVE DISEASES OF THE LUNG
Dec 14, 2015
Definition: TLC decreased by 20% compared to predictedvalues based on height, age, gender
RESTRICTIVE DISEASES OF THE LUNG
CAUSES OF PULMONARY EDEMA
1. Cardiogenic• Myocardial infarction• Hypertensive left heart failure
2. Increased capillary permeability• Inhaled or circulating toxins
• Endotoxin• High O2 over long periods of time• Radiation• SO2, NO2
• Bacterial and viral pathogens
left atrial pressure
pressure in pulmonary vein
Pcap
fluid flux across the endothelium
Cardiogenic pulmonary edema
Usually self correcting:•increased fluid flux increases PIF
•increased fluid flux concentrates proteins in capillaries, increasing cap
Increased capillary permeability
Inflammation
Increased permeability of pulmonary capillaries
Increased protein leak across capillaries
↓ cap
↑ fluid flux across capillaries
Usually not self limiting•fluid that leaks out has protein in it, increasing the oncotic pressure of the interstitial spaces
Symptoms
•dyspnea•cough (particularly in the recumbent position)•the cough is often non-productive in the early stages, but in the advanced stages, it may bring up pink foam,and cyanosis may be present
Pulmonary Function
•the PV curve of the lung is shifted downward and to the right•resistance to flow through airways may increase -(fluid forms around airways and isolates them from retractive forces
of the lung parenchyma)•TLC, VC, FRC decrease
Fluid andpus
Air
“Good” lung“Bad” lung(very stiff)
Breath only goes to good lung
Compliance = V/ P 2
Gas Exchange
If only interstitial edema is present•little change in blood gases
If alveolar edema is present•decreased PaO2 (due to shunt)•PaCO2 normal or even low (hyperventilation).•Reason for hyperventilation:
•low PaO2
•stimulation of lung receptors by high transpulmonary pressures (lung is stiffer, so it requires greater pressures for ventilation)
systemicinflammation
mechanicalunloading
adipocytederived hormones
FRC
VT
leptin
adiponectin
PAI-1
lungdevelopment
systemicinflammation
mechanicalunloading
adipocytederived hormones
FRC
VT
leptin
adiponectin
PAI-1
lungdevelopment
systemicinflammation
mechanicalunloading
adipocytederived hormones
FRC
VT
leptin
adiponectin
PAI-1
lungdevelopment
How does obesity impact:
1. Pulmonary mechanics
2. Pattern of breathing
3. Blood gases
4. Pulmonary Disease
How does obesity impact:
1) Pulmonary mechanics• Lung volumes• Airway caliber• Airway responsiveness
2) Pattern of breathing
3) Blood gases
4) Pulmonary disease
How does obesity impact:
1) Pulmonary mechanics• Lung volumes• Airway caliber• Airway responsiveness
2) Pattern of breathing
3) Blood gases
4) Pulmonary disease
www.lib.mcg.edu/.../4ch2/4ch2ques/4q2pg9.htm
www.lib.mcg.edu/.../4ch2/4ch2ques/4q2pg9.htm
Obesity makes thechest wall stiffer
Obese FRC
Chest wall in obesity
Lean FRC
Lean Obese
FRC
TLC
ERV
RV
Adapted From: Rubinstein et al Ann Intern Med 112:828-832, 1990.
(293 subjects)
RV airway closure
VC
How does obesity impact:
1) Pulmonary mechanics• Lung volumes• Airway caliber• Airway responsiveness
2) Pattern of breathing
3) Blood gases
4) Pulmonary disease
From: King et al: Eur. Respir. J. 25:896-901, 2005
Gaw is corrected for absolute lung volume Gaw = 1/Raw
The airways of obese subjects are narrowed. The airwaynarrowing is more than could be expected on the basis of reduced lungvolume alone.
Interim conclusion
What else is causing airway narrowing?
FACTORS PRODUCED BY ADIPOSE TISSUE
CYTOKINESTNFIL-6IL-1
PBEFTGFIL-10
CHEMOKINESIL-8
EotaxinMCP-1MIP-1
ENERGY REGULATING HORMONES
LeptinAdiponectin
Resistin
ACUTE PHASE REACTANTSSerum amyloid AC-reactive protein
PAI-11-acid glycoprotein
OTHER FACTORSAngiotensinogen
Complement B, C3, DAcylation-stimulating protein
VEGFIL-1RA
Retinol-binding protein-4
How does obesity impact:
1) Pulmonary mechanics• Lung volumes• Airway caliber• Airway responsiveness
2) Pattern of breathing
3) Blood gases
4) Pulmonary disease
How does obesity impact:
1) Pulmonary mechanics
2) Pattern of breathing
3) Blood gases
4) Pulmonary disease
Adapted from Sampson and Grassino, J. Appl. Physiol. 55:1269-1276, 1983.
Obesity leads to decreased tidal volume and increased frequency
How does obesity impact:
1) Pulmonary mechanics
2) Pattern of breathing
3) Blood gases
4) Pulmonary disease
work to move larger body weight
CO2 production
Most obese increase VE to maintain normal PaCO2
What about PaO2?
Lean Obese
FRC
TLC
ERV
RV
Adapted From: Rubinstein et al Ann Intern Med 112:828-832, 1990.
(293 subjects)
RV airway closure
VC
“Airway closure occurred within a tidal breath in 9 out of 10 (obese) subjects during spontaneous breathing”
“PaO2 correlated with the magnitude of airway closure”
Acta Anesthesiol Scand 20:334-42, 1976.
Airway closure
Shunt
↓PaO2
How does obesity impact:
1) Pulmonary mechanics
2) Pattern of breathing
3) Blood gases
4) Pulmonary disease
Obesity and Pulmonary Disease
•Asthma
•COPD
•Obstructive Sleep Apnea
•Obesity Hypoventilation Syndrome
•Pulmonary Hypertension
Obesity and Pulmonary Disease
•Asthma
•COPD
•Obstructive Sleep Apnea
•Obesity Hypoventilation Syndrome
•Pulmonary Hypertension
Obesity and COPD
From: Guerra et al, Chest 122:1256 - 1263 , 2002
Issues: lack of exercise, lifestyle factors
Obesity and Pulmonary Disease
•Asthma
•COPD
•Obstructive Sleep Apnea
•Obesity Hypoventilation Syndrome
•Pulmonary Hypertension
Sleep
muscles relax
tongue and soft palate fall against back of throat
obstruction
hypoxemia
arousal
Obstruction can occur 5-50 times per hour!
Outcomes:
•Loss of sleep•Excessive daytime sleepiness•Headaches upon awakening•Depression•Hypertension•Cardiovascular disease•Stroke
sleephelpusa.com/images/brewster-ginger.jpg
Obesity
Fat deposition in soft palate, uvula, neck area, pharynx
Increased risk of obstruction
Obesity and Pulmonary Disease
•Asthma
•COPD
•Obstructive Sleep Apnea
•Obesity Hypoventilation Syndrome
•Pulmonary Hypertension
Obesity Hypoventilation Syndrome (Pickwickian syndrome)
•Arterial hypercapnia (increased PaCO2) while awake•Hypersomnolence•Fatigue•Morning headaches•Hypoxemia•Polycythemia•Pulmonary hypertension•Right ventricular failure
Cause?
Sleep disordered breathing combined with chronic hypoxemia andhypercapnia leading to blunting of chemoreceptor responsiveness
Obesity and Pulmonary Disease
•Asthma
•COPD
•Obstructive Sleep Apnea
•Obesity Hypoventilation Syndrome
•Pulmonary Hypertension
Low PAO2 leads to constriction of pulmonary arterioles
“96% of obese subjects living at altitude have pulmonary hypertension”
Valencia-Flores et al Int. J. Obesity 28:1174-1180, 2004