Respiratory Flashcards
Respiratory Failure
What can cause the pulse oximetry to be inaccurate?
Compromised peripheral perfusion
True or false: you should rely on arterial blood gases in emergent settings.
False
Glasgow Coma Scale score of what indicates loss of protective airway reflexes and mandates intubation?
8 or less
What does a low paCO2 imply?
Respiratory compensation
What does an elevated paCO2 imply?
Respiratory failure
A 57 y.o. male presents with dyspnea. The ABG’s reveal a pH of 7.30, paCO2 of 55 mmHg, and a paO2 of 45 mmHg. What is the diagnosis?
Acute respiratory acidosis
A 57 y.o. male presents with dyspnea. He is one week post total hip arthroplasty. The ABG’s reveal a pH of 7.50, paCO2 of 25 mmHg, and a paO2 of 60 mmHg. What is the diagnosis?
•Acute respiratory alkalosis (P.E., pneumonia, CHF?)
A 57 y.o. male presents with dyspnea, hypotension and fever. UA reveals many WBC’s. ABG’s reveal a pH of 7.2, paCO2 of 20 mmHg, and a paO2 of 65 mmHg with an HCO3 of 10 mmol/L. What is the diagnosis?
•Acute respiratory alkalosis and metabolic acidosis.
A 57 y.o. male presents with dyspnea. SaO2 is 100%. ABG’s reveal a pH of 7.55, a paCO2 of 20 mmHg, and a paO2 of 92. What is the diagnosis?
•Acute respiratory alkalosis.
What are the clinical hallmarks of ARDS?
- Hypoxemia
- Bilateral radiographic opacities
What are the pathologic hallmarks of ARDS?
- Diffuse alveolar damage
- may or may not have focal hemorrhage
- Acute inflammation of alveolar walls
- Hyaline membranes
See differential diagnosis of ARDS (slide 19)
What factor distinguishes ARDS from ALI?
- ALI: PaO2/FIO2 < 300 mmHg
- ARDS: PaO2/FIO2 <200 mmHg
Both:
- Acute onset
- Bilateral alveolar or interstitial infiltrates
- PCWB < or = 18
- No evidence of increased LA pressure (signals CHF)
What are the management strategies for ARDS?
- Initiate volume/pressure limited ventilation
- Oxygenate
- Minimize acidosis
- Diuresis to decrease bp
PE/DVT
What score on the Modified Wells test indicates likely PE?
>4
Which method of D-Dimer assay is best? What does a positive assay indicate?
- Best test: quantitative rapid ELISA
- Positive assay: PE is likely
Where are most DVTs found? In which veins?
- Most found in the proximal veins of the legs
- Popliteal v
- Superficial femoral v
DVT is common in what type of cancer discussed in class?
Colorectal cancer
Pneumonia
What is used to determine how to treat pneumonia patients?
Demographics until the organism can be known
What defines pneumonia?
- New or progressive infiltrate (radiographic)
- Clinical evidence the infiltrate is infectious
- fever over 38
- leukocytosis or leukopenia
- purulent secretions
What is the test of choice to diagnose influenza?
Real-time reverse-transcriptase PCR
What is SIRS?
Systemic Inflammatory Response Syndrome
- Fever > 100.4 (38) or < 96.8 (36)
- HR > 90 bpm
- Resp. > 20 breaths/min or PaCO2 < 32mm
- Abnormal white blood cell count
What is sepsis?
SIRS + Infection
For what is the CURB 65 test used?
Determine the severity of illness
- Confusion
- Urea > 20 mg/dL
- Respirations (>30/min)
- Bp low (90/60)
- Age over 65
2 pts = moderate severity
3-5 = High severity
What are common pathogens causing HAP, VAP, and HCAP?
- Aerobic gram (-) bacilli
- pseudomonas
- E coli
- Klebsiella
- Acinetobacter species
- MRSA/staph aureus
If, during treatment, a pneumonia patient develops diarrhea, they should be tested for which bacteria?
C. diff
RISK FACTORS FOR MULTIDRUG-RESISTANT PATHOGENS CAUSING HOSPITAL-ACQUIRED PNEUMONIA, HEALTHCARE-ASSOCIATED PNEUMONIA, AND VENTILATOR-ASSOCIATED PNEUMONIA
- Antimicrobial therapy in preceding 90 d
- Current hospitalization of 5 d or more
- High frequency of antibiotic resistance in the community or in the specific hospital unit
- Presence of risk factors for HCAP:
- Hospitalization for 2 d or more in the preceding 90 d
- Residence in a nursing home or extended care facility
- Home infusion therapy (including antibiotics)
- Chronic dialysis within 30 d
- Home wound care
- Family member with multidrug-resistant pathogen
- Immunosuppressive disease and/or therapy
Pulmonary Function Tests
What does a concave flow-volume curve suggest?
Concave = mild to moderate airway obstruction
What does a prolonged finish “rat tail shape” flow-volume curve suggest?
Severe airway obstruction
What does a gradual volume-time curve that never plateaus suggest?
Airway obstruction
In a V/T curve, if the effort stops before 6s in adults or before 3s in children, what is indicated?
FVC may be underestimated
not a reasonable duration of effort
A low FEV1% (FEV1/FVC) of <70% predicted value indicates what?
Airway obstruction
A normal FEV1% (FEV1/FVC) with a low (<80% pred) FVC and FEV1 suggests what?
Restriction without obstruction
What classification of asthma severity is described?
- Normal FEV1 between exacerbations
- FEV1 >80% predicted
- FEV1% normal
Intermittent Asthma
What classification of asthma severity is described?
- FEV1 > 80% predicted
- FEV1% normal
Mild asthma
What classification of asthma severity is described?
- 60% < FEV1 < 80% predicted
- FEV1% reduced 5%
Moderate Asthma
What classification of asthma severity is described?
- FEV1 <60% predicted
- FEV1% reduced >5%
Severe asthma
What does spirometry measure?
Forced expiration
What is FVC?
Forced Vital Capacity: the max amount of air able to be exhaled on a single breath
What is FEV1?
Forced Expired volume in 1 Second
What is considered a positive response to administration of a bronchodilator?
an increase of >10% in either FVC or FEV1 in spirometry testing
What does a Helium Dilution test measure?
total amount of gas in the lungs after a complete inspiration
What does a body plethysmograph measure?
total amount of gas in the lungs after a complete inspiration
What is a normal range for:
- FEV1
- FVC
- FEV1/FVC
- TLC
- FRC
- RV
- DLCO
- FEV1 = 80-120%
- FVC = 80-120%
- FEV1/FVC > 0.70
- TLC = 80-120%
- FRC = 75-120%
- RV = 75-120%
- DLCO = 75-120%
***Remember 80%
What does a single breath diffusing capacity (DLCO) test measure?
the ability of the lungs to diffuse oxygen into, and carbon dioxide from, the bloodstream
What causes increased DLCO?
****More blood going to the chest****
- ¨Muller maneuver
- ¨Erythrocytosis
- ¨Under measured height or overstated age
- ¨Exercise
- ¨Supine position
- ¨Asthma
- ¨Alveolar hemorrhage
- ¨Left-to-right cardiac shunts
- ¨Obesity
- ¨CHF
What causes a decreased DLCO?
****Less blood or Hb going to the chest ****
- ¨Anemia
- ¨Elevated COHGB
- ¨Cigarette smokes
- ¨Emphysema
- ¨ILD
- ¨Valsalva Maneuver
- ¨Incorrect height or age
What drug is used in bronchial challenge tests?
Methacholine
TB
What is the characteristic histology in TB?
caseating granulomatous inflammation
(necrotizing)
How is TB spread?
Via respiratory route
Where are TB lung lesions located?
at the apex of the lung
What is the gold standard for TB diagnosis?
Positive acid fast culture
In TB infxn, what is abnormal about the body fluids?
- High proteins
- Mononuclear cells
How many drugs should initially be given to TB patients? What is the normal length of treatment?
- 4 drugs given until resistance is known
- duration: 6-9 months
When are TB patients no longer infectious?
3 negative AFB stains in a row
What are some modern day risk factors associated with development of asthma?
- Lack of physical activity
- Less time outside (exposure to Ags)
- Genetically engineered food
- Different and increased proteins in foods
- Obesity
What age group is most commonly affected by allergic asthma?
children < 16 yo
What are some red flags of allergic asthma?
- Family history of allergy
- Seasonal variation
- Rhinitis
- Eosinophilia
Aspirin-induced asthma is associated with what symptoms?
- Nonallergic rhinitis
- Nasal polyps
- Sinusitis
Omalizumab is an Ab against what? What does it treat?
Ab against IgE
Treats severe allergic asthmatics
What are the most common causes of Pulmonary effusion in the US?
(in order)
- CHF
- Infection (pneumonia)
- Malignancy
- PE
What pressure changes can cause pleural effusion? What are causes of these pressure changes?
- Increased capillary hydrostatic pressure (most common)
- CHF
- Decreased intravascular oncotic pressure
- hypoalbuminemia
- cirrhosis
What are the two clinical symptoms of pulmonary effusion?
- Dyspnea (effusion at least 500mL)
- Chest pain (worse with deep inspiration, signifies pleural irritation
What is tactile fremitus? What causes increased fremitus? What causes decreased fremitus?
Tactile fremitus is a vibration that you can feel with the palm of your hands when someone says “blue moon” or “99”.
- increased fremitus
- consolidation.
- decreased fremitus
- pneumothorax
- pleural effusion
What is egophony?
Egophony is the Greek word for “Voice of the Goat”. This sound is the “EEEEE” to “AAAAA” conversion that a person will make when being asked to say “EEEEE” while the auscultator listens to the lungs which is heard by the auscultator as “AAAAA” through the stethoscope.
Occurs with pleural effusion
When is diagnostic thoracentesis recommended? When is observation preferred?
- Diagnostic thoracentesis
- new and unexplained effusions
- Observation
- obvious CHF
- viral pleurisy
- recent surgery
What are the top causes of transudative etiologies?
- CHF
- Cirrhosis
- Renal failure
***usually benign***
What are the top causes of exudative effusions?
- Pneumonia
- Malignancy
- Infection
***malignant (not benign)***
What are Light’s criteria for exudate vs transudate?
- Pleural fluid protein / serum protein > 0.5
- Pleural fluid LDH / serum LDH > 0.6
- serum LDH = ULN (upper limit of normal)
Exudate if any of the above criteria apply
Transudate if none of the above apply
What levels of LDH, Cholesterol, and Protein are indicative of exudate?
- pleural fluid LDH > 0.45 ULN serum LDH
- Pleural cholesterol > 45 mg/dL
- Pleural protein > 2.9 g/dL
If a pleural effusion has an LDH > 1000 IU/L and a glucose < 30 mg/dL, what is the diagnosis?
Empyema
or
Rheumatoid arthritis
If a pleural effusion has an LDH > 1000 IU/L and a glucose 30-50 mg/dL, what is the diagnosis?
Malignancy
If a pleural effusion has a glucose of 30-50 mg/dL, ADA > 43 U/mL and a normal LDH, what is the diagnosis?
TB
What is the pH of transudate fluids?
Of exudate fluids?
- Transudate = 7.4 - 7.55 (goes down only a little)
- Exudative = 7.3 - 7.45 (goes down a lot)
- Normal = 7.6
At what pH does an effusion necessitate drainage?
pH < 7.1 - 7.2
Normal = 7.6
What does salivary amylase in a pleural effusion indicate?
Esophageal rupture