Respiratory Flashcards
(24 cards)
Common causes of transudative pleural effusion.
CHF, cirrhosis with ascites, nephrotic syndrome
Fluid is sterile, pushed out of vessels into pleural space due to hydrostatic pressure.
Troubleshooting the PLEUR VAC
If there’s and increase of bubbling amount and frequency in the water chamber, there’s air in the pleural space. Look for big changes.
Troubleshhooting: look for kinks, obstruction, tube migration and leaks
What is the MRC dyspnea scale?
Grades severity of dyspnea in respiratory disease
For bonus points:
0) breathless with strenuous exercise
1) SOB when hurrying on level ground or walking uphill
2) walk slower than others in own age group on level ground, or stop for breath when walking at own pace
3) stop for breath after 100 meters or a few minutes on level ground
4) too breathless to leave the house or breathless when dressing/undressing
Hemoptysis treatment considerations
- If bleeding source is known, position bleeding side down.
- Manipulate intubation to ventilate “good” lung, i.e. right mainstem. If this is done, reduce Vt to avoid overpressurizing the one good lung.
- Anticoagulant reversal
- PPV with PEEP may assist.
What are the commonly prescribed antibiotics for pneumonia?
Azithromyacin and ceftriaxone
Significance and determination of empyema
Watch for empyema as it’s a common sepsis source!
Serum will show pH <7.3, increased lactate, proteins and/or LDH compared to blood sample.
Suspect empyema if pt is febrile, hemodynamically unstable, or has productive cough.
Empyema tx is drainage, antibiotics and possibly thrombolytics into pleural space to break off loculated empyemas. Thoracic surgery in severe cases.
Hemoptysis causes and concerns
Bleeding is either localized or diffuse due to alveolar damage.
Most often caused by CA, TB, PE or pneumonia.
Over 150cc of blood in 24 hours is very concerning as there is always more blood below than what is brought up. Biggest concern is asphyxiation.
RARELY causes hypovolemia
Common causes of exudative pleural effusion
- Infection (TB/pneumonia/abcess)
- Malignancy
- Pulmonary embolism
- Pancreatitis
- Post cardiac injury syndrome
Inflammatory process causes effusion
What are the two antifibrotics prescribed for interstitial lung disease?
Perfedinone & Ninetedanib
We care, because if a patient has these prescribed they are likely ILD patients.
Which prescribed medication for pulmonary hypertension should NEVER be stopped?
It’s delivered by pump…
Epoprostenol: a pulmonary vasodilator that has a very short half life. Discontinuing may cause a sudden increase in RV afterload leading to acute RV failure.
Mech Vent strategies in pulmonary hypertension
- Avoid hypoxemia, hypercarbia and acidosis as they will worsen PVR (further vasoconstriction) and therefore RV function.
- Avoid high inspiratory pressure and auto PEEP to keep intrathoracic pressure as low as possible.
- Ketamine is a preferred induction agent due to its bronchodilatory properties. Use lower end of dosing to prevent any adverse effects.
- Give pressors prior to intubation. Norepi provides a balance of inotropic support without increasing heart rate or PVR. Vasopressin can also be considered as it may actually reduce PVR while increasing SVR.
- Be prepared for PEA arrest shortly after intubation.
Most pressing is the demand on the RV, and the conflicting increase in RV afterload that comes with PPV. Efforts should be made to reduce RV afterload and PVR prior to intubating.
5 mechanisms of hypoxia
and possible treatments
1) Decreased atmospheric pressure
increase FiO2
2) V/Q mismatch
position for perfusion, adress hemodynamics, O2 and ventilation
3) R-L shunt (extreme V/Q, ASD or VSD), suspect in failure of PaO2 to rise despite increased FiO2.
4) Increased O2 extraction
reduce demand
5) Diffusion impairment
Increase surface area, reduce membrane thickness
Hypoventilation may be considered as a 6th mechanism, though this is more associated with hypercapnia.
Treatments for COPD exacerbations
Similar to asthma, with exclusion of epi* and higher suspicion of infectious cause so earlier antibiotic administration.
See pulmonary hypertension considerations for mechanical ventilation. NIPPV may be effective.
*COPD is an alveolar disease, and epi works on bronchioles, so considering risk/benefit profile in these patients - who often have comorbidities, epi is relatively contraindicated here.
What rating scales are used for pneumonia patients?
The PSI (pneumonia severity scale) helps determine the need for ICU care, and CURB-65 predicts mortality.
COPD ABG considerations
These patients are usually hypercapnic at baseline. A derangement in pH indicates an acute-on-chronic exacerbation, as new metabolic compensation takes 3-5 days to actualize.
Describe FEV1/FVC ratio and its significance
Compares fraction of exhaled air in 1st second to total amount exhaled forcefully after a deep breath. Should be <0.7. If the FEV1 is <50%, this indicates severe obstructive disease.
What’s the cause of obstructive shock leading to cardiac arrest in a tension pneumothorax?
Compression of the cavo-atrial junction.
Patho, signs and treatment for re-expansion pulmonary edema
Occurs when rapid re-expansion causes negative pressure in the alveoli, dragging fluid into them.
Patients develop SOB/CP, crackles, increased rate and amount of fluid in chest tube.
- clamp tube (release can then be titrated to pt. symptoms)
- sit upright to drain edema to bases
- O2 & supportive care
Common causes of COPD exacerbation
- Infection (50%)
- CHF/MI
- Allergen exposure
- PE (20-25%!)
- unknown
Risk factors and causes of interstitial lung disease (ILD)
Risks are age >50, male, smoking hx, reflux and genetics.
Caused by:
* exposures birds, mold, farms
* meds amiodarone, metotrexate
* connective tissue disease scleroderma
* granulomas sarcoid, TB, fungal
May also be idiopathic
What is the significance of clubbing?
Usually occurs in chronic conditions. Most common causes are malignancy, TB and liver disease.
Structural clues for differing etiologies in chest xrays
Think heart, diaphragm, trachea
Is it collapse, cells or fluid/pus?
Atalectasis will “suck in” structures
A mass will push them away
Consolidation will keep them the same
What is the A-a gradient
Difference betwen alveolar (A) and arterial (a) oxygen content. Usually between 5-15mmHg
Cardiac consequences of pulmonary hypertension, AKA: the vicious RV overload cycle
- As PH progresses, the RV becomes overloaded, whic eventually decreasesLV preload through septum shift and reduced LV contractility, as well as “tugging” on the LV.
- This causes reduced CO, leading to,
- Systemic hypotension, and,
- Reduced RV tissue perfusion and RV free wall ischemia, and then,
- Reduced RV contractility - which brings us back to No. 1 again!
