module 6: respiratory disorders Flashcards
what is dyspnea and signs of it?
discomfort in breathing (SOB)
- signs:
- flaring of the nostrils
- use of accessory muscles for respiration
what is orthopnea dyspnea?
dyspnea upon lying down
- causes abdominal contents to put pressure on the diaphragm
what is paroxysmal nocturnal dyspnea (PND)
awakening at night with dyspnea
- doesn’t last too long.. catch breath and all good
what are 7 other symptoms/signs of respiratory disease
- cough
- abnormal sputum
- hemoptysis
- abnormal breathing pattern
- cyanosis
- clubbing
- pain
why would a cough be a sign/symptom of respiratory disease?
can build up mucous because irritant receptors are lower down the “respiratory tree”, so the body doesn’t recognize it right away = secretion build up
what is abnormal sputum?
mix of saliva and mucous… changes in the amount, colour, and consistency depending on infection
what is hemoptysis?
expectoration (coughing) of blood
what is cyanosis?
bluish discoloration of the skin and mucous membranes
- caused by deoxygenated hemoglobin in the blood
what is clubbing?
selective bulbous enlargement of the end of a digit and irregularity of nail bed
- often seen with cystic fibrosis
- chronic lack of O2
Define hypercapnia (hypercarbia)
increased carbon dioxide in the arterial blood
- too much CO2
- CO2 normally diffuses way easier… problem is not CO2 diffusion to alveoli, the problem is ventilation into the lungs
what is the immediate cause of hypercapnia?
- hypoventilation of the alveoli
- CO2 passes very easily from the blood to the alceolar space = NOT the problem
- problem is with the echange in the alveolar gasses that occurs with ventilation
what are 3 occurances that can bring the immediate cause to happen with hypercapnia?
- drugs
- diseases of the medulla (because responsible for breathing pattern/functions that keep us alive)
- physiologic dead space (areas where we are not able to have normal gas exchange)
Define hypoxemia and explain the difference from hypoxia
- hypoxemia = reduced oxygenation of arterial blood (lack of o2 in blood stream)
- hypoxia = reduced oxygenation of cells
what are the 3 mechanisms of hypoxemia?
- oxygen delivery to the alveoli
- diffusion of oxygen from the alveoli into the blood
- anatomical right to left shunting
explain how oxygen delivery to the alveoli can reduce oxygenation of the blood
- not enough o2 in the atmosphere
- not vetilating O2 properly to hold air in (not able to draw air fully)
By what two means can oxygen delivery to the alveoli be decreased? Be familiar with examples of conditions/diseases that can cause this
- balance between alveolar ventilation (V) and perfusion (Q):
- perfusion = the amount of blood passing through the alveolar capillaries
- V/Q imbalance/mismatch causes hypoxemia
- inadequate perfusion of well-ventailated area (high V/Q), producing alveolar dead space (blod not going anywhere)
- low ventilation, but high perfusion (low V/Q) = physiologic right to left shunt (figure 1) = blood flow is fine, but at lungs, there is a disruption, so not picking up o2
- decreased diffusion across the alveolocapillary membrane
- due to thickened membrane brought about through edema or fibrosis
- alveolocapillary = area that is diffusing there to disrupt o2 movement
what is the difference between the physiologic right to left shunt and an atomic right to left shunt?
- physiologic right to left shunt = blood flow is fine, but at lungs, there is a disruption = not picking up o2 (look at figure)
- problem with drawing air in
- anatomic right to left shunt = hole in heart septum = instead of blood pushing to lungs fully, some goes to the left side of the heart = problem with blood flow
What does V/Q refer to?
- alveolar ventilation (V) = bringing air to lungs/alveoli
- perfusion (Q) = ability of blood to get to capillaries and out
- high V/Q = inadequate perfusion of well-ventilated area, producing alveolar deadspace
- low V/Q = inadequate ventilation of well-perfusion area of lung (AKA physiologic right to left shunt)
What is the most common cause of hypoxemia?
V/Q mismatch
what are examples of diseases that cause low and high V/Q
- high V/Q = pumonary embolism
- low V/Q = atelectasis, asthma, pulmonary edema
What conditions can decrease diffusion across the alveolocapillary membrane?
- thickened membrane brought on through edema or fibrosis
how can an uncorrected left-to-right shunt progress to a right-to-left shunt?
- muscle through LV is a lot thicker because it is pumping blood to the whole body, whereas RV pump blood to lungs only
- since left-to-right shunt = blood pushing to right side of heart (more preload to RV), the right side will start to pump harder to compensate for the increased blood flow = increase of RV muscle size
- increase of RV muscle size eventually shifts the left-to-right shunt to a right-to-left-shunt
What causes, and is the result of, chest wall restriction?
- cause - when the chest wall is:
- deformed
- traumatized
- immobilized
- heavy from the accumulation of fat
- results - a decrease in tidal volume
- amount of air taken in and released during normal breathing in reduced
Describe flail chest
- multiple consecutive ribs that are broken (example of trauma to the chest)
- if you break ribs, it disrupts the attachment onto ribs = no attachment of muscle = can’t move well = loses structure
Define pneumothorax and its effect on the lung
- air in the pleural space caused by a rupture in the visceral or parietal pleura
- effect on lung:
- air pushes on the outside of the lung and makes it collapse
what is open pneumothorax?
- air comes in through pleura on the side
- when we inhale, diaphragm pulls down, but air coming from the side pushes collapsed lung and shfits everything over
explain tension pneumothorax
- when inhaling, air comes in and shifts everythign over
- air is not able to leave during expiration (due to flap/opening closing) = huge amount of air iin lung, causing major compression on both lungs
- the tissue folds over and blocks opening as. we exhale and opens as we inhale
Define pleural effusion and how it usually occurs
- excess fluid in pleural space from pressure of membranes in pleura
- occurs through migration of fluid through walls of capillaries bordering the pleura
Define empyema and how it can occur
- infection of pleural space/effusion = a collection of pus in pleural space
- can occur through complications of pneumonia, surgery, etc.
what is atelectasis?
- collapsed lung by external compression, obstructed airways (alveoli colllapses), inhalation of concentrated oxgen, or decreased production of surfactant (lungs stick is there is lack of surfactant)
what are the causes of atelectasis?
- post-surgery
- patients in pain
- breathe shallowly
- produce viscous secretions
what are the manifestations of atelectasis?
- dyspnea
- cough
- fever
- leukocytosis
What medical procedure often results in atelectasis and what measures can be taken to improve patients’ condition?
- surgery
- measures taken:
- breathe deeply
- become ambulatory (up and moving) asap
- change positions frequently when lying down to avoid obstruction of airway
Describe bronchiectasis and identify some causes
- permanent dilaion of the bronchi
- con’t move air through trees well and damage epithelial lining = lack of circulation = can’t kill pathogens as well
- causes: chronic inflammation = destruction of elastic and muscular components on bronchi walls = permanent dilation
Describe the pathophysiology behind cystic fibrosis and its treatment
- autosomal (chromosomes that aren’t sex chromosomes) recessive disorder
- Pathophysiology:
- mutation of chromosome (2 bad genes) produces inability of cell membranes to transport chloride ion = series of events happen = increased absorbance of sodium and water from respiratory secretions
- increased sodium and water = production of thick mucous that cilia has trouble moving
- mucous accumulaes and increases risk of infections
***CAN HAVE 1 BAD GENE AND NOT NOTICE A DIFFERENCE.. If parents both have shitty chromosome, can have 25% chance of having child with cystic fibrosis***
- treatment:
- antibiotics to control infection
- possible replacement of pancreatic enzymes
What is a pulmonary embolism and of what is the most common embolus comprised?
- occlusion of a portion of the pulmonary vascular bed by an embolus
- embolus went from deep vein thrombosis to the heart
- most common embolus comprised = a clot from deep venous thrombosis involving the lower leg
What does obstruction of blood flow cause in the lung and what is the result if the clot is not dissolved soon enough?
- obstruction causes pulmonary vessels to constrict = impaired gas exchange (V/Q mismatch- high V/Q problem)
- right heart failure can happen if clot is not dissolved soon enough