Module 8: Disorders of Ventilation and Gas Exchange Flashcards
Bronchiectasis
Abnormal permanent dilation of the large bronchi
An obstructive issue like COPD - hard to get the air out/CO2 out
Bronchiectasis is associated with…
infection and destruction of the bronchial walls
Why does infection occur in bronchiectasis?
Usually bronchi are straight, but this weakening can allow outpouching that fills with debris and can become a medium for bacterial growth and lead to lung and bronchial tube infections
Causes for Bronchiectasis
- local airway obstructions like tumors and foreign bodies
- congenital abnormalities
- lung infections (tb, fungal, lung abcess etc)
- cystic fibrosis
- immunodeficiency states
- exposure to toxic gases
Where can bronchiectasis occur?
It can be localized or generalized
Can be bilateral
Bronchiectasis impacts __ lobes more than __ lobes
lower ; upper
As bronchiectasis progresses what things can it develop and progress into?
Bronchial obstruction atelectasis smooth muscle relaxation dilation of the airway walls airway remains patent infection inflammation impaired mucociliary function pooling of secretions chronic inflammation development of new infections
Atelectasis
Alveolar collapse (no surfactant to prevent collapse)
“Empty Balloon syndrome”
can lead to complete or partial lung collapse and leads to less oxygenation in the body
Does atelectasis only occur with Bronchiectasis?
no it can happen with other things like post surgically
What happens if there is impaired mucociliary function
the secretions can pool and not push debris out and this allows a vicious cycle of infection to occur
chronic bronchitis can occur leading to more COPD
Is there a cure for Bronchiectasis?
No the only thing to do is detect it early to prevent permanent damage
Manifestations of Bronchiectasis
Fever
Recurrent Bronchopulmonary infection
Coughing
Production of copious amounts of foul smelling purulent sputum
Hemoptysis (from damage to the bronchial wall)
Weight Loss
Anemia
Marked Dyspnea and Cyanosis
Foul breath in bronchiectasis may lead to …
a bad taste in the mouth and not wanting to eat leading to subsequent weight loss
How does anemia relate to bronchiectasis
it could be an underlying factor leading to bronchiectasis or something that the bronchiectasis caused
Bronchiectasis is an ___ disorder by nature
obstructive
Why does cyanosis and dyspnea occur in bronchiectasis?
There is inability to exchange gasses from atelectasis or mucus
Cystic Fibrosis
An autosomal recessive genetic defect affecting the exocrine glands and cells leading to large amounts of thick mucous
These secretions collect and inspissate in ducts
How does Cystic Fibrosis work genetically?
Autosomal recessive
1 in 29 carry the gene on chromosome 7
there are 200 different types of defects
most fatal genetic disease in Caucasian newborn (1:2000)
Dx usually around 1 mo to 2 yrs
Not sex linked
Median survival age is 38
___ does not always go with cystic fibrosis but commonly does go with it?
Bronchiectasis
Inspissate
To thicken by evaporation or absorption of fluid
So this is the mucus in cystic fibrosis getting thick and acting like a sponge thus causing some atelectasis
There is ion channel dysfunction with CF, so what would this mean?
there are increased concentrations of sodium and chloride in the sweat of a patient with CF
Absorption Atelectasis
Thick secretions in CF causing fluids to be pulled into them - this also pulls fluids/surfactant in the alveoli causing decreased surface tension and collapse
What are the effects of CF on the pulmonary system?
Blocks alveolar ventilation
Absorption atelectasis
Chronic inflammation
Edema of capillary-alveolar interface
Bronchial scarring and fibrosis destroying the bronchial airways
Reduced lung compliance
Developing overinflated barrel chest
Increased risk of pneumonia and chronic bronchitis
Bronchiectasis
Increased incidence of nasal polyps and URIs
Digit Clubbing in severe cardiopulmonary disease
What does the edema of the capillary-alveolar interface impact the body in CF?
fluid/mucus fathers between cells of the alveoli and blood - building up in the interstitial space - and this leads to increased distance between O2 and CO2 to diffuse (increased diffusion capacity)
This leads to making it harder for CF to oxygenate tissues
In CF, Scarring from repeated infection leads to…
bronchial airways being destroyed from not stretching
What happens if you cannot get the bronchi and alveoli to stretch?
Usually sucking air down the bronchus will make the diaphragm flatten but if they cannot stretch then you lose a major way of getting air into the lungs leading to reduced lung compliance
What effects does CF have on the pancreas?
Pancreatic Ducts Clog
Digestive Enzymes do not reach S intestine
Pancreas gets destroyed - digestion of pancreatic parenchymal tissue occurs
decreased insulin secretion and diabetes can occur
What effects does CF have on the Liver?
Small bile duct obstruction
Biliary cirrhosis
Portal HTN (hard knotty liver means greater HTN leading to blood going through collateral vessels not detoxed)
Liver failure
What effects does CF have on the intestine?
Blocks digestion and absorption
Malabsorption of fats, carbs, and proteins
FTT (Failure to thrive) is a common complication
Poor nutritional status
Why does CF lead to malnutrition, liver failure, and potential diabetes?
There is a block in the common bile duct for the pancreas and liver, the enzymes from the pancreas cannot get through to digest food causing issues with the alpha, beta, and gamma cells potentially leading to diabetes.
The block also makes bile back up leading to not being able to digest fats either, and the backup causes increased pressure in the liver leading to destruction, disease, cirrhosis, and inflammation which will lead to portal hypertension
Portal Vein
3-4 inch long vein that branches let and right into the liver
It moves blood from the spleen and GI tract to the liver for detoxification (75% of blood)
Portal Hypertension
an issue of pressure buildup and destruction in the liver leading to issues in getting blood through the portal vein
the blood will travel through collateral vessels instead, and bypass the liver, and this causes unfiltered blood to circulate
Effects of CF on the Cardiac System
Cor Pulmonale (R Sided HF)
Effects of CF on the Reproductive System
Male - obstructed vas def –> aspermia
Female - thick mucus secretion in cervix blocking entrance –>sterility
Effects of CF on sweat glands
impaired reabsorption of Na and Cl in sweat ducts
Excessive salt loss in sweat
Heat prostration (exhaustion)
Dehydration
Hyponatremia
Hypochloremia
Effects of CF on Dentition
gingivitis
dental caries
Why does CF lead to cor pulmonale
The pressure builds up in the lungs, and the right ventricle is not strong enough to move against it and this causes right sided heart failure
What do normal sweat glands release
isotonic fluids with sodium and chloride in it as salt and water
What do CF sweat glands release
Normal sweat ducts are permeable to Cl, but CF sweat ducts are relatively impermeable to Cl
Cl makes the sweat excessively negatively charged and this attracts Sodium (positive) to come with it leading to blood hyponatremia and hypochloremia
How much more is the concentration of salt in CF sweat compared to those without it?
4-5x more
Why do dental issues occur with CF?
The salivary ducts are clogged and cannot make saliva to clear out bacteria and protect teeth
Respiratory manifestations of CF
wheezing
chronic cough
dyspnea
tachypnea
barrel chest
cyanosis
Developmental manifestations of CF
delayed weight gain
retarded bone growth
delayed sexual development
GI manifestations of CF
inspissated meconium in fetal gut
meconium ileus
chronic recurrent abdominal pain
GERD
abdominal distention
frequent steatorrhea
vitamin deficiencies (ADEK)
rectal prolapse
inspissated mucofecal masses
chronic constipation
voracious appetite
What is neonate meconium ileus?
an emergency situations where the infant cannot pass their meconium leading to bowel obstruction that becomes toxic and requires immediate surgical intervention
Can occur in CF
Why does Steatorrhea occur in CF?
They have no bile breaking down fat, so the stool becomes large, greasy, and bulky since fat is coming through
It is pale since bile usually gives the brown color and malodorous
Why is impaired fat digestion so serious in CF?
we need fat for our myelin sheathes on our nerves
we need fat to get fat soluble vitamins like ADEK
Why should babies never have only skim milk?
a lack of fat in the diet can cause impairments in cognition and development because of impaired development of the CNS that still occurs post partum
Rectal prolapse
large intestine coming out of the anus
comes from straining and issues passing stool (especially with CF)
Mucofecal Masses
very hard to pass masses of mucus leading to prolapsed anus, hemorrhoids, and chronic constipation
What ways is CF diagnosed?
Sweat Test
Genetic Screening
CXR
Stool Sample
Sweat Test
test done between 1 month old and 20 years old to check for CF
If there is failure of the ion channels there will be too much Cl- in the sweat
What value of Cl- is indicative of CF
> 60 mEq/L
What sort of genetic tests can be done to check for CF?
recombinant DNA
amniocentesis
What may a CXR look for in a patient with suspected CF
Hyperinflation - from barrel chest dev
Widespread consolidation - from fibrotic changes and scarring
Blebs
Bronchiectasis
RUL involvement and pulmonary infiltrates
What is the most common location of pulmonary infiltrates?
R Upper Lobe
Blebs
lung blister filled with fluid
What is absent in the stool of someone with CF?
The digestive enzymes trypsin and chymotrypsin
What is normal fecal fat levels compared to CF fecal fat levels?
Normal -4g
CF - 15-30g
When do CF patients take pancreatic enzymes and why?
They need to take the enzymes with food to prevent malabsorption
This is because the enzymes and food must reach the duodenum at the same time
CF is Autosomal ___
recessive
What are the odds for children between 2 heterozygous parents for CF?
25% of CF
50% of carrier
25% of no disease or carrier
(total 75% chance of no disease)
What is the chances for a person to have CF if the parents are Homozygous dominant and recessive respectively?
100% chance of being a carrier
What are the odds for children between someone with CF and a heterozygous carrier?
50% chance of carrier
50% chance of CF
Pulmonary arteries carry…
deoxygenated blood from the heart to the lungs (unlike normal arteries)