2-1: Respiratory Flashcards
Which nerve innervates the diaphragm and where does it originate?
the phrenic nerve, originating at C3-C5
What are factors that can affect oxygen’s affinity for hemoglobin?
- oxygen levels
- carbon dioxide levels
- temp
- 2, 3 - DPG
- pH
What does 2, 3 - DPG do to the oxygen?
it encourages it to offload from the hemoglobin
What does a left shift in the ODC mean for oxygen delivery?
hgb holds tighter to oxygen and there is less oxygen released to the tissues
What does a right shift in the ODC mean for oxygen delivery?
hgb releases oxygen easier resulting in more oxygen released to the tissues
What is the V/Q ratio and what does a V/Q mismatch most commonly cause?
- the balance between ventilation in the lungs and perfusion in the body
- mismatch is the most common cause of respiratory failure
What does a low V/Q look like?
- poor ventilation
- there is adequate blood flow, but the alveoli aren’t inflated to capacity to exchange gas
What does a high V/Q look like?
- good ventilation
- poor blood flow to alveoli makes them less able to get rid of what they need to get rid of
What is FiO2?
the concentration of oxygen in the gas mixture
What is PEEP?
Positive end-expiratory pressure (PEEP) is the alveolar pressure above atmospheric pressure that exists at the end of expiration. There are two types of PEEP:
●Extrinsic PEEP – PEEP that is provided by a mechanical ventilator is referred to as applied PEEP
●Intrinsic PEEP – PEEP that is secondary to incomplete expiration is referred to as intrinsic PEEP or auto-PEEP
What is the normal tidal volume for an adult?
400-500 mL
What are the indications for using oxygen?
- saturation of <92%
- known or expected anemia (trauma, GI bleed)
- altitude sickness
- paraquat/diquat, CO, or cyanide
- abruptio placenta or prolapsed cord
What is COPD
a condition which results in a decreased forced expiratory volume per second
COPD - Chronic Emphysema
what happens physiologically and what can happen?
- permanent enlargement of the air spaces that are distal to the terminal bronchioles
- destruction of the alveolar walls
- partial collapse of terminal
bronchioles - loss of elastic recoil of the lungs
What are some abnormalities associated with emphysema?
- increased air trapping
- loss of recoil
- loss of alveolar surface area due to alveolar and capillary destruction
- bullae formation
- increased dead space
- increased work of breathing
What might you hear upon auscultation of a pt with emphysema?
distant, diminished breath sounds and diffuse wheezing
What will the radiograph of a pt with emphysema show?
flattened, low diaphragm
hyperlucent lung fields
wide intercostal spaces
long, narrow heart shadow
What is the clinical definition of chronic bronchitis?
the presence of a productive cough for three months out of the year for two years in a row.
What is the pathophysiology of chronic bronchitis?
chronic irritation results in hyperplasia of the tracheobronchial mucus glands and goblet cells
this results in an increase in mucus production
What will you hear when listening to the chest of someone with chronic bronchitis?
course crackles, wheezing over smaller airways, ronchi over larger airways
What circumstances will cause hyperglycemia in a pt with chronic bronchitis? What will cause hypoglycemia?
hyperglycemia:
- stress response/elevated cortisol levels
- use of B-agonists/corticosteroids
hypoglycemia:
- increased work
- poor stores
When should you consider RSI for your COPD patient?
- respiratory failure
- fatigue
- AMS
- worsening respiratory acidosis
- hypoxemia refractory to supplemental O2 administration
What are your vent settings for a COPD patient?
TV:
Rate:
Mode:
FiO2:
TV: 5-8 mL/kg
Rate: 12-18/min
Mode: VC or PRVC
FiO2: 1.0 (1.0 means 100% oxygen, 0.8 means 80% oxygen, and so on…)
How long do corticosteroids such as methylprednisolone take to have effect?
6-8 hours
what does AMS in the asthma patient indicate?
severe hypoxia and impending respiratory arrest
What might you hear when listening to the lungs of an asthma patient?
diffuse wheezing
ronchi may be heard if mucus present
“silent chest” ominous finding
Treatment for an asthma patient is similar to that for a COPD patient EXCEPT?
- asthmatics don’t require antibiotics
- mag sulfate used more in asthma
What is pulmonary arterial hypertension?
the pulmonary arteries have a higher-than-normal pressure, causing an increased workload for the right side of the heart.
What are factors that can cause PAH?
- decreased prostacyclin
- increased thromboxane
- vasoconstriction —> thrombosis
less severe PAH patients can be managed with what medications (3)?
calcium channel blockers, endothelin antagonists, and phosphodiesterase inhibitors
More severely ill PAH patients require what kind of therapy?
What are some other meds?
prostacyclin therapy
flolan
veletri (epoprostinol)
remodulin (treprostinil)
ventavis (Iloprost)
What two things should you NEVER do when transporting a patient with PAH on a med pump?
- NEVER titrate infusion without med control
- NEVER flush the IV line in which the med is being administered
What is the second most common cause of sudden unexpected natural death at any age?
pulmonary embolus (second to CAD)
What is a pulmonary embolism?
the occlusion of the pulmonary artery or one of its branches by an embolus carried by the bloodstream.
What type of V/Q mismatch do we see in patients with a PE?
- blood flow decreased to the alveoli
- ventilation unaffected
What does a PE do to the RV afterload?
increases it
What are the most common symptoms of a PE?
- dyspnea
- pleuritic chest pain
- cough
- hemoptysis
What is the most important diagnostic tool in the investigation of a pulmonary embolism?
the history
What is the gold standard diagnostic test for identifying a PE?
CT scan or CT angiography
What do the early and late radiographs of a PE show?
early: initially normal
late:
- atelectasis
- westermark sign (pulmonary vessel dilation and a sharp cutoff)
- pleural effusion
How do we feel about using ABGs in the setting of a PE?
don’t use em, they can be unreliable
What are the most common EKG abnormalities seen with PE?
- sinus tachycardia
- non-specific ST changes
the ABSENCE of EKG abnormalities doesn’t mean anything in the setting of a PE
What can happen if you give fluids to someone with a massive PE?
a drop in BP
What is the priority after securing the airway and ensuring adequate ventilation in someone with a massive PE?
eliminating the clot and preventing further thrombosis
What can cause ARDS?
any condition that produces a systemic inflammatory response:
- increased ICP
- sepsis (most common)
- COVID
- prolonged hypotension/shock
- and more
Is ARDS an inflammation process or an infection process?
inflammation
How might you describe the lungs in the acute phase of ARDS?
congested and heavy
Which study findings will point towards a clinical diagnosis of ARDS?
gas exchange values and radiograph
Is a radiograph reliable for distinguishing ARDS?
No, don’t know if the bilateral infiltrates are from ARDS or cardiogenic pulmonary edema
What happens if the vented ARDS pt is positioned laying supine and why?
the ventral alveoli are over-inflated and the dorsal alveoli are collapsed under the weight of the fluid in the lungs.
Why are vented ARDS patients put in the prone position?
gravity causes the fluid to shift into the ventral aspect of the lungs, which doesn’t affect as many of the lung fields
more alveoli are recruited
What are the two types of pneumonia?
- community-acquired
- hospital-acquired
What are some risk factors associated with aspiration pneumonia?
- stroke with deficits
- esophageal motility/swallowing disorders
- seizures/syncope
- intubation
What are some risk factors associated with bacteremia pneumonia?
indwelling devices:
- vascular devices
- GI/GU devices
- intrathoracic devices
What will auscultation of the pneumonia pt sound like?
crackles, ronchi, diminished breath sounds
The head of the bed should be elevated ____ degrees for pneumonia patients?
30
What does iatrogenic mean?
illness caused by a medical treatment or procedure
What things might cause a spontaneous and iatrogenic pneumothorax?
- PPV
- mechanical ventilation
- central line placement
- NG tube placement
- tracheostomy
- bronchoscopy
- CPR
What disease is most commonly associated with spontaneous pneumothorax?
COPD
What is the pathophysiology of a pneumothorax
- air in the intrapleural space
- there are negative pressures in the intrapleural space and greater pressures in the alveoli
- in a pneumo, air moves from the alveoli into the pleural space
- as the lung collapses, the pneumo increases
How do young and healthy people usually tolerate a pneumothorax?
“quite well” with mild tachycardia and tachypnea
Which types of patients are at risk for developing a simple pneumothorax?
- mechanically ventilated patients
- patients flown at altitude
What diagnostic studies are required for the dx of tension pneumo?
none
what is the immediate treatment of a tension pneumothorax?
needle decompression
What is a tube thoracostomy used for?
removal of abnormal accumulations:
- blood
- air
- fluid
What position should the head of the bed be raised for a stable patient receiving a tube thoracostomy?
30 - 60 degrees
Where is a tube thoracostomy placed when the goal is air removal? what size tube?
2nd intercostal space at the midclavicular line
- 16-20 Fr
Where is a tube thoracostomy placed when the goal is fluid removal?
What size tube?
4th/5th intercostal space at the midaxillary line
- 20-36 Fr
If unsure of the patient’s anatomy, it is better to place a thoracostomy tube ______ (high or low). Why?
High
too low may result in:
- injury to the diaphragm
- intra-abdominal placement
what are the contraindications to tube thoracostomy?
none in the unstable trauma patient
What is the valve in a tube thoracostomy called and why is it used?
Heimlich valve
- one way valve allows for flow outside of the chest, prevents air from entering the chest
What is the mnemonic for assessing the drainage unit of a chest tube?
FOCAL
F- fluctuation (height of fluid level in drainage tube fluctuates with respiration)
- Absence of fluctuation indicates that the system is blocked or the lung is fully expanded
O- output (assess amount and consistency)
C- color
A- air leak (if present, repair)
L- levels
Ensure adequate water levels in the chambers and proper negative pressure levels
What are some ways you can troubleshoot a tube thoracostomy
- look/listen for air leak
- make sure all connections are tight
- make sure all distal fenestrations of the tube are within the thorax
- tape connections where a leak is possible
- clamp tube to the chest
What is the difference between anaphylaxis and anaphylactoid
Anaphylaxis is immune-mediated (by Ig-E) and anaphylactoid is a similar reaction but is not immune-mediated
What is a normal inspiration to expiration (I:E) ratio?
1:2 - expiration is 2x as long as inspiration
what is characterized by increased air trapping secondary to bronchiole collapse and loss of recoil and reduction of total alveolar-capillary membrane surface area secondary to alveolar and capillary destruction?
Chronic emphysema
Which disease is characterized by cyanosis and peripheral edema, giving rise to the “blue bloater” phrase?
chronic bronchitis
What are three pathological changes that contribute to airflow obstruction in the asthmatic
- mucous plugging
- bronchospasm
- airway inflammation and edema
What is the number 1 cause of ARDS?
Sepsis
What skills do prehospital providers do that may result in an iatrogenic pneumothorax?
- CPR
- PPV
- NG tube placement
What are the s/s of a pneumo in a mechanically vented patient?
- fighting the vent
- tachycardia
- hypotension
- hypoxia
- acute increase in the inspiratory and/or static airway pressure
- cardiovascular collapse
what methods can be used to confirm chest tube placement?
- drag a finger along length of tube as finger is removed from pleural space
- observe condensation in the tube
- free flow of blood or fluid
- ability to rotate tube freely
- pt is improving
- auscultation of lung sounds
- chest radiograph
Will a vented COPD patient require higher or lower vent rates and why?
lower, to prevent breath stacking
What is the reason for death occurring in a tension pneumothorax?
due to decreased preload leading to decreased cardiac output
What is the typical amount of wall suction required for a chest tube?
20 cmH2O
