Respirology Flashcards
Discuss signs of consolidation
- filling of airspace with fluid, pus, blood or cells
Radiological Signs
- increased opacity obsuring pulmonary vessels
- air bronchogram sign
- silhouette sign
- RML = right heart border
- RLL = right hemi-diaphragm
- Lingula = left heart border
- LLL = left-hemidiaphragmDiscuss signs of atelectasis
- collapse of alveoli
Radiological Signs - volume loss indicating elevated hemidiaphragm, mediastinal and tracheal shift toward ipsilateral side
- increased opacity of the collapsed part of lung with straight margin
- no air bronchogram
Discuss signs of pleural effusion
- increased pleural fluid that may displace the lung
Radiological Signs - blunting of costophrenic angle
- increased opacity with a meniscus
- tracheal shift towards contralateral side
Discuss signs of lung mass
- nodule: discrete focal opacity <3cm in diameter, benign 65% of time
- mass: discrete focal opacity >3cm in diameter, malignant 95% of time
- benign lesions tend to be small <1cm, have stable size for 2 years, have smooth margins and have diffuse or central calcifications
Discuss signs of pneumothorax
- air in pleural space Radiological Signs - air outside of lung - no vessel marking - sharply demarcated edge - tracheal shift to contralateral side
Discuss signs of pulmonary edema
- increased fluid in interstitial space Radiological Signs - reticular markings - Kerley B lines - bronchial wall thickening - vascular indistinctness of hila - vascular redistribution - cardiomegaly and bilateral pleural effusion
Discuss findings in the Pulmonary Function Test
Flow Volume Loop
- scooped flow volume loop suggest obstructive disease
- peaked flow volume loop suggest restrictive disease
Look at FEV1/FVC, FVC, and TLC
- FEV1/FVC <70% predicted then obstructive or mixed
- TLC <80% then mixed
- FVC >80% and TLC >80% then obstructive
- FEV1/FVC >70% then restrictive or normal
- FVC >80% and TLC >80% then normal
- FVC <80% and TLC <80% then restrictive
Look at DLCO to narrow differential
- normal with DLCO >80% then normal
- normal with DLCO <80% then pulmonary vascular disease, anemia, smoking, early interstitial lung disease
- restrictive with DLCO >80% then chest wall or neuromuscular disease
- restrictive with DLCO <80% then interstitial lung disease
- obstructive with DLCO >80% then asthma, chronic bronchitis
- obstructive with DLCO <80% then emphysema
Discuss the severity by PFT results
Obstructive - FEV1 >80% mild - FEV1 50-80% then moderate - FEV1 30-50 then severe - FEV1 <30 then very severe Restrictive - TLC <80% then mild - TLC 50-80% then moderate - TLC <50 then severe DLCO - 60-80% then mild - 40-60% then moderate - <40% then severe
Discuss the causes of hypoxemia
Low FiO2
- low fraction of inspired O2
- normal Aa gradient
- high altitude
Hypoventilation
- Decreased minute ventilation
- normal Aa gradient, corrected with supplemental O2
V/Q Mismatch
- abnormal ventilation to perfusion ratio
- increased Aa gradient, corrected with low to moderate O2 supplementation
- asthma, COPD
- pneumonia
- interstitial lung disease
- pulmonary hypertension or pulmonary embolism
Diffusion Block
- abnormal alveolar capillary interface that decrease gas diffusion
- increased Aa gradient, exercise induced/exacerbated hypoxemia
- pneumonia, pulmonary edema
- interstitial lung disease
Shunt
- right to left shunt when blood passes from right to left side of heart without being oxygenated
- increased Aa gradient, cannot be corrected with O2
- atelectasis
- severe pneumonia, pulmonary edema
- right to left cardiac shunt
Discuss the Aa gradient
Aa= [FiO2(Patm-PH2O)-(PaCO2/RQ)] - PaO2
Aa=[150-1.25(PaCo2)]-PaO2
- normal <15mmHg
List the common pathogens for community acquired pneumonia
Typical - Strep pneumonia - haemophilus influenza - moraxella catarrhalis - enterobacteria including Kliebsiella, E coli - staph aureus Atypical - Chlamydia pneumonia - Mycoplasma pneumonia - Legionella pneumonia Aspiration - anaerobes Ventilator Acquired Pneumonia - pseudomonas aeruginosa - klebsiella - acinebacter - enterobacter - proteus
Discuss the pathophysiology and complications of pneumonia
Pathophysiology
- pathogen enter respiratory tract through direct inhalation, aspiration, direct spread from upper respiratory tract, or hematogenous spread
- pathogen colonize and proliferate
- immune system cause inflammation and migration of neutrophils into air space
Complications
- pleural effusion which can be transudate or exudate (empyema)
- lung abscess
- pneumatocele
- necrotizing pneumonia
- right heart failure
- dehydration
Discuss the presentation and investigations for pneumonia
Presentation
- productive cough with colored sputum
- SOB
- pleuritic chest pain
- fever, chills
- dullness to percussion
- increased tactile fremitus
- crackles and decreased air entry
- increased whispered pectoriloquy
- egophany
Investigations
- CBC, electrolytes, BUN, blood glucose and blood gas
- Chest x-ray
- bronchopneumonia: diffuse patchy consolidation with multiple foci of isolated consolidation
- lobar pneumonia: localized continuous consolidation of distinct region
- intersitial pneumonia: reticular nodular pattern with increased lung markings throughoutDiscuss the indications for hospitalization for pneumonia
Pneumonia Severity index - class 1 and 2 as outpatient - class 3 treated in observation or short hospitalization - class 4 and 5 as inpatient CURB65 - Confusion - Urea >7 - Respiratory Rate >30 - BP <90 or <60 - Age >65 - <=1 can be treated as outpatient, 2 as inpatient, >=3 in ICU
Discuss antibiotic choice for inpatient pneumonia
Choice
- Ceftriaxone 1g IV Q24H + Azithromycin 500mg IV Q24 if
- severely ill with HR>125 or hypotension <90, tachypnea >30 or hypoxic <90%
- allergy to quinolone
- received quinolone within last 3 months
- Otherwise Levofloxacin 750mg PO Q24H
Switch from IV to PO
- hemodynamically stable
- clinical improvement
- ability to tolerate PO
- normal functioning GI tract
Stepping Down Ceftriaxone + Azithromycin
- Cefuroxime 500mg PO Q12H +/- Azithromycin 250-500mg PO Q24H
- Levofloxacin 750mg PO Q24H
Duration
- discontinue if patient afebrile for 2-3 days and have <=1 of the CAP associated signs of instability
- temperature >37.8
- HR >100
- Systolic BP <90
- RR >24
- O2 Sat <90% on room air or PaO2 <60
- Altered mental status
- 5 days for patients that are not immune compromised or do not have structural lung disease
- 7 days for patients who are moderately immune compromised or structural lung disease
- 10 days for slow clinical response or significant immune compromised
Discuss signs and investigations for pleural effusion
Presentation
- possibly asymptomatic
- SOB
- asymmetric chest expansion
- dullness to percussion, decreased tactile fremitus
- decreased air entry
Investigation
- Chest x-ray
- Thoracocentesis (if >1cm of fluid on lateral decubitus x-ray)
- appearence of pleural fluid
- cell count and differential
- biochemistry: LDH, protein, glucose, pH, albumin
- gram stain, acid fast stain, culture
- cytology
Discuss the Light’s criteria for transudative vs exudative pleural effusion
Exudative if any of the following
- pleural fluid protein/serum protein >0.5
- pleural fluid LDH/serum LDH >0.6
- pleural fluid LDH >2/3 upper normal limit of serum LDH
Discuss the differential for transudative vs exudative effusion
Transudative - CHF - nephrotic syndrome - hypoalbumin (liver failure) Exudative - infection - malignancy - pulmonary embolism
Differentiate between para-pneumonic effusion and empyema
Parapneumonic effusion is pleural effusion related to pneumonia abscess or bronchiectasis
- can progress to empyema
- Pleural fluid >=7.2 in parapneumonic
- glucose >=3.33
- LDH <1000
- Gram stain negative
- No frank pus
Discuss the pathophysiology of Asthma
- variable airflow limitation and airway hyperresonsiveness represented by exaggerated contractile response of the airway to variety of stimuli
- atopic march: eczema, food allergies, environmental allergies
- strongest predictor for development
Discuss the symptoms and diagnosis of asthma
Signs and Symptoms
- Wheezing
- Cough
- Dyspnea
- Reduce air entry on auscultation
Diagnosis
- obstrutive pattern on spirometry
- Children 6-11 have FEV1/FVC <0.8 and increased FEV1 post-bronchodilator >=12%
- Adults have FEV1/FVC <0.75 and increase in FEV1 post-bronchodilator by >=12% and >=200mL
- scooped flow volume curve
- high residual volume RV/TLC >0.35
- methacholine challenge where have >20% drop in FEV1 with <4mg/mL of methacholine
- FEV1 drop of >10% at 80% of maximum HR
Discuss possible triggers for asthma exacerbation
- Allergens exposure
- Respiratory infection
- Cigarettes
- Animal dander
- Dust mites
- cold/dry air
- exercise or emotional factors
- B Blockers/ASA/NSAIDs
Discuss the management of asthma
- Environmental control
- Education
- Action plan
Medication - Short-Acting Bronchodilator on demand for very mild
- Inhaled Corticosteroid for maintenance therapy for mild asthma (symptoms 3x per week)
- leukotriene receptor antagonist second line
- start at low dose and progress - Long acting bronchodilator used as third line add on
- must be on ICS if using LABA
- if less than 12 then increase ICS before - Third line to add LTRA
- Fourth line prednisone
Discuss the characteristics of good asthma control
- Daytime Symptoms <4x/week
- Nighttime symptoms <1x/week
- Normal physical activity
- Infrequent and mild exacerbation
- No absences due to asthma
- Need for SABA <4dose/week
- FEV1 >=90% best
- sputum eosinophils <2-3%
Discuss the pathophysiology and symptoms of COPD
Pathophysiology
- airflow limitation caused by inflammatory response to inhaled toxins
Signs and Symptoms
- Productive cough
- Dyspnea
- Decreased breath sounds
- Wheezes
- Prolonged expiratory phase of breathing
Investigations
- PFT: FEV1/FVC <0.7 with no improvement with bronchodilator
- Spirometry increased FRC, RV and decreased VT
- CXR: hyperinflation of lung with flattended diaphragm
Discuss the Triggers and Signs of COPD exacerbation
Triggers - Respiratory infection - Environmental pollution - pulmonary embolism - comorbid respiratory or cardiac condition Signs - Change in amount or color/purulence of sputum - More short of breath - change in mood - Fatigue
Discuss the MRC dyspnea scale of symptoms and impairement of lung function
Normal
- MRC 1 dyspnea only with strenuous exercise
- Normal spirometry
Mild
- MRC 2 dyspnea when hurring on level ground or walking up hill
- FEV1 >80% predicted and FEV1/FVC <0.7
Moderate
- MRC 3 walk slower than people because of breathlessness or has to stop for breath
- MRC 4 stop for breath after walking 100m
- 50% <= FEV1 < 80% predicted
- FEV1/FVC <0.7
Severe
- MRC 5 too breathless to leave house or breathless with dressing
- 30%
Discuss the management of COPD
Education - inhaler - action plan Smoking Cessation - most important intervention to slow lung decline Exercise or Pulmonary Rehabilitation - All patients should exercise Vaccination - influenza - Pneumovax <65 or Prevnar >65 Pharmcotherapy - Mild: SABA prn - Moderate: SABA and LABA/LAAC prn - Severe (>1 AECOPD/year): Long acting anticholinergic + ICS/LABA + SABA prn Oxygen - severe hypoxemia (PaO2 <55mmHg or SaO2 <88%) - PaO2 <59mmHg or SpO2 <89% with evidence of right heart failure or cor pulmonale or erytrhocytosis (Hct >55%) Surgery - lung volume reduction surgery Lung Transplant - FEV1 <25% - PaCO2 >55 - pulmonary hypertension
Discuss the indications for hospitalization for AECOPD
Hospitalized if any of the following
- inadequate response to outpatient emergency department management
- marked increase in dyspnea
- severe underlying COPD, FEV1 <50%
- inability to eat or sleep
- new cyanosis or worsening hypoxemia
- Acute respiratory acidosis
- Change in mental status
- Insufficient home support
- High risk comorbidities
Discuss the in-hospital management of AECOPD
Treatment
- target O2 >90%
- albuterol 2.5mg by nebulizer Q1-4H or 4-8 puffs with spacer
- Ipratropium 500mcg nebulizer Q4H or 2-4 puffs
- systemic steroids (prednisone 40mg PO for 5 days)
Non-Invasive Positive Pressure Ventilation
- respiratory distress: tachypnea >25 RR or use of accessory muscles
- respiratory acidosis: pH <7.35 or PaCo2 >45
Antibiotics
- uncomplicated (<65yo, FEV1 >50%, <3 exacerbations a year, no cardiac disease)
- Azithromycin 500mg POx1d then 250mg Q24H for 4d
- Cefuroxime 500mg PO Q12H
- Doxycycline 100mg PO Q12H x1d then 100mg Q24H
- Septra 1 tab PO Q12H
- Complicated (any of above risk factors)
- Levofloxacin 750mg Q24H
- Amox-Clav 875mg Q12H x1d then 100mg Q24H
- Pseudomonas then Cirpofloxacin
- Abx for 5d if mild-mod, 7d for severe
List the Common Asthma/COPD Inhalers and their side Effects
SABA (blue) - Salbutamol (ventolin) - tachycardia - arrhythmia - irritability - difficulty sleeping - muscle cramps LABA (orange) - formoterol (oxeze) - salmeterol (serevent) - same as SABA ICS (red) - Fluticasone (flovent) - Beclomethasone (ovar) - hoarseness - sore throat - thrust ICS + LABA - Fluticasone + Salmeterol (Advair - purple) - Pulmicort + Oxeze (Symbicort - red) - shaky hands - tachycardia - thrush - sore throat - hoarse Short-Acting Anticholinergic - Ipratropium bromide (atrovent) - dry mouth - urinary retention Long-Activing Anticholinergic - Tiotropium (spiriva) - same as SAAC
Discuss the presentation and consequences of OSA
Symptoms - snoring, apnea, choking - morning headache - GERD - poor quality of sleep resulting in daytime sleepiness, impaired memory/concentration and depression Long-term - systemic hypertension - increased risk of stroke or MI - increased risk of AF or CHF - increased risk of pulmonary hypertension as have vasopasm of pulmonary arteries from decreased desats - increased risk of diabetes - increased risk of depression - daytime hypercapnia and hypoxemia
Discuss the management of OSA
Indications - symptomatic - AHD >=15 as incrase cardiovascular risk - occupation - presence of comorbid condition Non-Specific - weight loss - avoid substances - positional therapy (side sleeping) - avoid sleep deprivation Nasal continuous Positive Airway Pressure (CPAP) - 1st line - continuous blowing of room air into airway splinting it open - BiPAP for larger adults requiring greater pressure Surgery - for underlying anatomical problem
Discuss the diagnosis of OSA
Must have A or B and C
A: Excessive daytime sleepiness that cannot be explained
B: >=2
- recurrent choking or gasping in sleep
- recurrent awakening from sleep
- daytime fatigue
C: Apnea hypopnea index (apnea + hypopnea/hrs asleep) >5 (mild:6-15/hr, mod:16-30/hr, sev: .30/hr)
- hypopnea is decreased airflow by 50% with decreased O2 sat by >4% or EEG arousal
List the definition and risk factors for apnea
Apnea: cessation of airflow for >10 seconds or 2 breath cycles
- obstructive: cessation >10s despite respiratory efforts
- central: cessation for >10s with no respiratory effort
Risks for OSA
- male
- older age >45
- obesity, including pregnancy
- increased neck circumference (normal is 17.5 in men and 15.5 in women)
- substances (smoking, alcohol, sedative, opioid)
- medications
- any structural abnormality with airway
- increased mallampati score
- family history
Discuss the differential for Chronic Cough
Mechanical - post-nasal drip - GERD Infection - TB - pneumonia Inflammation - COPD - Asthma Medication - ACE inhibitor Neoplasm - Bronchogenic carcinoma - lung cancer - lung metatasis Other - intersitial lung disease
Discuss the investigation for chronic cough
PFT with Methcholine Challenge
- if hx suggest asthma
PPI
- for GERD
Abx
- pneumonia: purulent sputum, systemic signs of infection
Smoking Cessation
Stop ACE Inhibitor
Non of the Above
- CXR
- Normal CXR then 3 week empiric anti-histamine for post-nasal drip
- if partially effective add nasal glucocorticoid
- CT
- Bronchoscopy
- Cardiac Studies
