Pulmonary Medicine




(1)
Division of Pulmonary Medicine, Department of Medicine, University of Alberta, Edmonton, AB, Canada

 




Asthma Exacerbation



Differential Diagnosis of Wheezing



EXTRATHORACIC AIRWAY OBSTRUCTION





  • oropharynx—enlarged tonsils, retropharyngeal abscess, obesity, post-nasal drip


  • larynx—laryngeal edema, laryngostenosis, laryngocele, epiglottitis, anaphylaxis, severe laryngopharyngeal reflux, laryngospasm


  • vocal cords—vocal cord dysfunction, paralysis, hematoma, tumor, cricoarytenoid arthritis


INTRATHORACIC AIRWAY OBSTRUCTION





  • tracheal obstruction—tracheal stenosis, tracheomalacia, tracheobronchitis (herpetic, fungal), malignancy, benign tumor, aspiration, foreign body


  • tracheal compression—goiter, right-sided aortic arch


  • lower airway obstruction—asthma, COPD, bronchiolitis, bronchiectasis, carcinoid tumor, aspiration, malignancy


  • parenchyma—pulmonary edema


  • vascular—pulmonary embolism


Pathophysiology



EXACERBATORS OF ASTHMA





  • infections—viral, bacterial, fungal


  • outdoors—respirable particulates, ozone, sulfur dioxide, cold air, humidity, smoke


  • indoors—smoke, dust mites, air conditioners, humidity, perfumes, scents, mold, animal dander


  • non-adherence


Clinical Features



HISTORY

—history of asthma and any life-threatening exacerbations, number of ER visits/hospital admissions in the last 6 months (or ever), any ICU admissions, previous prednisone use, triggers for attacks, usual peak expiratory flow rate, change in peak flow rates, wheezing, cough, dyspnea, decreased function, exercise limitation, nocturnal symptoms, absenteeism from work/school, postnasal drip, recurrent sinusitis, GERD, past medical history, medication history, psychosocial issues, occupational and work environment, home environment (pets, heating source, filter changes)


PHYSICAL

—HR ↑, RR ↑, pulsus paradoxus, O2 requirement, moderate-severe dyspnea, barrel chest, cyanosis, hyperresonance, decreased breath sounds, wheezing, forced expiratory time


TYPES OF WHEEZING

—inspiratory wheeze and expiratory wheeze are classically associated with extrathoracic and intrathoracic airway obstruction, respectively. However, they are neither sensitive nor specific and cannot help to narrow differential diagnosis


Investigations



BASIC





  • labs—CBCD, lytes, urea, Cr, troponin/CK


  • microbiology—sputum Gram stain/AFB/C&S, nasopharyngeal swab for viral studies


  • imaging—CXR


SPECIAL





  • ABG—if acute respiratory distress


  • peak flow meter—need to compare bedside reading to patient’s baseline


  • spirometry/PFT (non-acute setting)—↑ FEV1 >12% and an absolute ↑ by 200 mL post-bronchodilator suggests asthma


  • methacholine challenge (non-acute setting)—if diagnosis of asthma not confirmed by spirometry alone. A decrease of FEV1 >20% after methacholine challenge suggests asthma. Sens 95%


  • sputum eosinophil counts (non-acute setting)—performed in specialized centres for monitoring of asthma control in patients with moderate to severe asthma

Can Resp J 2012 19:2


Acute Management



ABC

—O 2 to keep sat >92%, IV


BRONCHODILATORS

—salbutamol 100 μg MDI 2 puffs q6h ATC + q1h PRN and ipratropium 20 μg MDI 2 puffs q6h ATC (frequency stated is only a guide, may increase or decrease on a case by case basis)


STEROID

—prednisone 0.5–1 mg/kg PO daily × 7–14 days (may be shorter depending on response) or methylprednisolone 0.4–0.8 mg/kg IV daily (until conversion to prednisone)


OTHERS

—if refractory case and life-threatening, consider IV epinephrine, IV salbutamol, theophylline, inhaled anesthetics, MgSO4


MECHANICAL VENTILATION

—BiPAP, intubation


Long-Term Management



EDUCATION

—smoking cessation (see p. 480). Asthma action plan. Puffer technique education and review


ENVIRONMENTAL CONTROL

—avoidance of outdoor/indoor allergens, irritants, and infections; home environment cleanliness (e.g. steam cleaning)


VACCINATIONS

—influenza vaccine annually and pneumococcal vaccine every 5 years


FIRST LINE

—SABA (salbutamol 100 μg MDI 2 puffs PRN). Proceed to second line if using more than 2×/week or 1×/day for exercise-induced symptoms, symptoms >2×/week, any nocturnal symptoms, activity limitation or PEF <80%


SECOND LINE

—low-dose ICS plus short-acting β2-agonist PRN


THIRD LINE

—moderate-dose ICS, combined ICS plus LABA (note that long-acting β2-agonist should never be used alone in asthma), or leukotriene receptor antagonist (most effective in asthma complicated with sinus disease and exercise-induced asthma). May also consider using single inhaler budesonide/formoterol combination therapy as both a controller and an acute reliever


FOURTH LINE

—anti-IgE therapy (omalizumab) for refractory allergic asthma, administered subcutaneously q2–4 weeks, dosed by IgE level and body weight, for add-on therapy or inadequately controlled moderate-to-severe allergic asthma despite use of high doses of inhaled corticosteroid therapy

NEJM 2009 360:10

Can Resp J 2012 19:2


Treatment Issues



ASTHMA CONTROL CRITERIA







































Characteristic
Frequency or value

Daytime symptoms
<4 days/week

Night-time symptoms
<1 night/week

Physical activity
Normal

Exacerbations
Mild, infrequent

Absence from work or school due to asthma
None

Need for a SABA
<4 doses/week

FEV1 or PEF
≥90% personal best

PEF diurnal variationa

<10–15%

Sputum eosinophils
<2–3%


aDiurnal variation is calculated as the difference between the highest and lowest PEF divided by the highest PEF multiplied by 100 for morning and night (determined over a 2 week period)


COMMON INHALED MEDICATIONS





  • short-acting β–agonists (SABA)—salbutamol MDI 100 μg 1–2 puffs PRN or 2.5 mg NEB PRN, fenoterol MDI 100 μg 1–2 puffs PRN, terbutaline 500 μg INH PRN


  • short-acting anticholinergics—ipratropium MDI 20 μg 2 puffs QID or 500 μg NEB QID


  • long-acting β–agonists (LABA)—formoterol 6–24 μg INH BID, salmeterol diskus 50 μg i puff BID


  • long-acting anticholinergics—tiotropium 18 μg INH daily


  • inhaled corticosteroids—beclomethasone 125–250 μg INH BID, budesonide turbuhaler 200–400 μg INH BID or 0.5–1 mg NEB BID, fluticasone 125–250 μg INH BID, ciclesonide MDI 100–400 μg INH daily (only indicated for asthma at this time, not COPD), mometasone twisthaler 100–400 μg INH BID


Related Topics

Chronic Obstructive Pulmonary Disease (p. 4)

Pulmonary Function Tests (p. 25)


ADMISSION CRITERIA









































 
FEV1 (L)
PEF (L/min)
PaO2

Action

Very severe
–
–
<90% with O2

Admit

Severe
<1.6 (<40%)
<200 (<40%)
<90%
Admit

Moderate
1.6–2.1
200–300
>90%
Admit?

Mild
>2.1 (>60%)
>300 (>60%)
>90%
Send home




  • DISCHARGE CRITERIA—consider discharging patient if peak flow >70% of usual (or predicted) value for at least 1 h after bronchodilator


OXYGEN DELIVERY DEVICES






































































Device
Flow rates
Delivered O2

Nasal cannula
1 L/min
21–24%
 
2 L/min
25–28%
 
3 L/min
29–32%
 
4 L/min
33–36%
 
5 L/min
37–40%
 
6 L/min
41–44%

Simple oxygen face mask
6–10 L/min
35–60%

Face mask with oxygen reservoir (non-rebreather mask)
6 L/min
60%
 
7 L/min
70%
 
8 L/min
80%
 
9 L/min
90%
 
10–15 L/min
95 + %

Venturi mask
4–8 L/min
24–40%
 
10–12 L/min
41–50%




  • NOTE: delivered O2 (FiO2) is approximate. Oxygen delivery can approach 100% with intubation and mechanical ventilation


Specific Entities



EXERCISE-INDUCED ASTHMA





  • pathophysiology—mild asthma with symptoms only during exercise due to bronchoconstriction as a result of cooling of airways associated with heat and water loss


  • diagnosis—spirometry. Exercise or methacholine challenge may help in diagnosis


  • treatments—prophylaxis with salbutamol 2 puffs MDI, given 5–10 min before exercise. Consider leukotriene antagonists or inhaled glucocorticoids if frequent use of prophylaxis


TRIAD ASTHMA

(Samter’s syndrome)—triad of asthma, aspirin/NSAIDs sensitivity, and nasal polyps. Cyclooxygenase inhibition → ↓ prostaglandin E2 → ↑ leukotriene synthesis → asthma symptoms. Management include ASA/NSAIDs avoidance and leukotriene antagonists (montelukast)


ALLERGIC BRONCHOPULMONARY ASPERGILLOSIS (ABPA)





  • pathophysiology—associated with asthma and cystic fibrosis. Due to colonization of the airways by Aspergillus fumigatus, leading to an intense, immediate hypersensitivity-type reaction in the airways


  • clinical features—history of asthma, recurrent episodes of fever, dyspnea, and productive cough (brownish sputum). Peripheral eosinophilia. CXR findings of patchy infiltrates and central bronchiectasis, CT chest findings of central bronchiectasis, “finger-in-glove” appearance (i.e. mucous-filled dilated bronchi)


  • diagnosis—above clinical features plus Aspergillus extract skin test, serum IgE level, sputum for Aspergillus and/or serologic tests (IgE and IgG against Aspergillus)


  • treatments—systemic glucocorticoids, itraconazole


COPD Exacerbation


NEJM 2004 250:26


Differential Diagnosis of Acute Dyspnea



RESPIRATORY





  • airway—COPD exacerbation, asthma exacerbation, acute bronchitis, infectious exacerbation of bronchiectasis, foreign body obstruction


  • parenchyma—pneumonia, cryptogenic organizing pneumonia (COP), ARDS, acute exacerbation of interstitial lung disease


  • vascular—pulmonary embolism, pulmonary hypertension


  • pleural—pneumothorax, pleural effusion


CARDIAC





  • myocardial—HF exacerbation, myocardial infarction


  • valvular—aortic stenosis, acute aortic regurgitation, mitral stenosis, endocarditis


  • pericardial—pericardial effusion, tamponade


SYSTEMIC

—sepsis, metabolic acidosis, anemia


OTHERS

—neuromuscular, psychogenic, anxiety


Pathophysiology



PRECIPITANTS OF COPD EXACERBATION

—infections, lifestyle/environmental (10% [cigarette smoke, dust, pollutants, cold air]), non-adherence, pulmonary embolism, pulmonary edema, pneumothorax, progression of COPD


Clinical Features



RATIONAL CLINICAL EXAMINATION SERIES: DOES THE CLINICAL EXAMINATION PREDICT AIRFLOW LIMITATION?



















































































































 
LR+
LR–

History

Smoking >40 pack-years

12

0.63

Smoking ever
1.8
0.16

Sputum >1/4 cup
4
0.84

Chronic bronchitis Sx
3
0.78

Wheezing
3.8
0.66

Any exertional dyspnea
2.2
0.83

Coughing
1.8
0.69

Any dyspnea
1.2
0.55

Physical

Barrel chest
10
0.90

Decreased cardiac dullness
10
0.88

Match test
7.1
0.43

Rhonchi
5.9
0.95

Hyperresonance
4.8
0.73

FEV1 >9 s
4.8
–

FEV1 6–9 s
2.7
–

FEV1 <6 s
0.45
–

Subxyphoid cardiac apical impulse
4.6
0.94

Wheezing

4.4

0.88

Maximum laryngeal height ≤4 cm

4.2

0.70

Pulsus paradoxus (>15 mmHg)
3.7
0.62

Decreased breath sounds

2.6

0.66

Accessory muscle use
–
0.70

Clinical Judgement

Overall Clinical Prediction of Moderate-Severe Disease

5.6

–

Overall Clinical Prediction of Mild Disease

2.3

–




  • APPROACH—“no single item or combination of items from the clinical examination rules out airflow limitation. The best findings associated with increased likelihood of airflow limitation are objective wheezing, FEV1 >9 s, positive match test, barrel chest, hyperresonance and subxyphoid cardiac impulse. Three findings predict the likelihood of airflow limitation in men: years of cigarette smoking, subjective wheezing and either objective wheezing or peak expiratory flow rate”

    JAMA 1995 273:4




  • UPDATE—multivariate ‘Rule In’ Obstructive Disease Model (history of obstructive airways disease, smoking >40 pack-years, age ≥45, and laryngeal height ≤4 cm) has posterior odds of disease of 220. Multivariate ‘Rule Out’ Obstructive Disease Model (smoking <30 years, no wheezing symptoms, and no auscultated wheezing) has posterior odds of disease of 0.02.

The Rational Clinical Examination. McGraw-Hill, 2009


Investigations



BASIC





  • labs—CBCD, lytes, urea, Cr, troponin/CK, Ca, Mg, PO4


  • microbiology—sputum Gram stain/AFB/C&S/fungal, nasopharyngeal swab for viral studies


  • imaging—CXR


  • ECG—left atrial enlargement, atrial fibrillation, sinus tachycardia


  • spirometry / PFT—FEV1/FVC <0.7, may be partially reversible. Severity based on FEV1


  • ABG—if acute respiratory distress


SPECIAL





  • BNP—if suspect HF


  • D-dimer, CT chest—if suspect PE


  • echocardiogram


Prognostic Issues



PROGNOSIS OF PATIENTS WITH ACUTE EXACERBATION OF COPD

—in-hospital mortality 5–10%


GOLD CLASSIFICATION 2007

—all have FEV1/FVC <0.7



  • stage I ( mild )—FEV1 ≥ 80% predicted


  • stage II ( moderate )—FEV1 50–79% predicted


  • stage III ( severe )—FEV1 30–49% predicted


  • stage IV ( very severe )—FEV1 < 30% predicted, or <50% predicted + cor pulmonale


BODE INDEX





  • BMI—0 points = >21, 1 point = ≤21


  • obstruction (post-bronchodilator FEV1)—0 points = ≥65% predicted, 1 point = 50–64%, 2 points = 36–49%, 3 points = ≤35%


  • distance walked in 6 min—0 points = ≥350 m, 1 point = 250–349 m, 2 points = 150–249 m, 3 points = ≤149 m


  • exercise MMRC dyspnea scale—0 points = 0–1, 1 point = 2, 2 points = 3, 3 points = 4


  • scoring—total BODE score calculated as sum of all points. Relative risk for death (any cause) is increased by 34% per one-point increase in BODE score. Relative risk for death (from respiratory failure, pneumonia, or pulmonary embolism) is increased by 62% per one-point increase in BODE score

NEJM 2004 350:10


Acute Management



ABC

—O 2 to keep sat >90%, or 88–92% if CO2 retainer, IV


BRONCHODILATORS

—salbutamol 100 μg MDI 2 puffs q4h ATC + q1h PRN and ipratropium 20 μg MDI 2 puffs q4h ATC


STEROIDS

—prednisone 40–60 mg PO daily × 5–14 days (tapering dose not always necessary) or methylprednisolone 60–125 mg IV q6-12 h (inpatient)


ANTIBIOTICS

—give if any two of the following criteria are met: ↑ sputum purulence, ↑ dyspnea or ↑ sputum volume. Other considerations include the need for non-invasive mechanical ventilation and “at risk” for poor outcome (substantial comorbidities, severe COPD, frequent exacerbations >3/year, recent antibiotics within 3 months); choices depend on clinical circumstance (levofloxacin 500 mg PO daily × 7–10 days [or 750 mg PO daily × 5 days if no renal disease], doxycycline 100 mg PO BID × 7–10 days, amoxicillin 500 mg PO BID × 7 days, cefuroxime 250–500 mg PO BID × 10 days, or azithromycin 500 mg PO × 1 day then 250 mg PO daily × 4 days)


MECHANICAL VENTILATION

—BiPAP, intubation


OTHERS

—DVT prophylaxis (unfractionated heparin 5000 U SC q8-12 h, enoxaparin 40 mg SC q24h, dalteparin 5000 U SC q24h), physiotherapy

NEJM 2002 346:13


Long-Term Management



EDUCATION

—smoking cessation (see p. 480). Disease-specific self-management program. Puffer technique education and review


VACCINATIONS

—influenza vaccine annually and pneumococcal vaccine booster every 5 years


REHABILITATION

—education and exercise training (increases quality of life and exercise tolerance); pulmonary rehabilitation associated with ↓ risk of recurrent exacerbation in patients with moderate to very severe COPD and recent AECOPD (<4 weeks)


FIRST LINE

—SABA or short-acting anticholinergic on an as-needed basis


SECOND LINE

—LABA or long-acting anticholinergic (tiotropium 1 puff [18 μg/puff] INH daily) plus SABA PRN. Consider early initiation of long-acting agents if requiring regular PRN short-acting agents as long-acting agents are superior


THIRD LINE

—LABA plus long-acting anticholinergic, with SABA PRN


FOURTH LINE

—long-acting anticholinergic plus LABA/ICS (e.g. Advair, Symbicort). No role for ICS monotherapy. Consider phosphodiesterase-4 inhibitor (roflumilast 500 μg PO daily) as adjuvant maintenance therapy in moderate to severe COPD with ≥1 exacerbation in previous year. Consider mucolytic agents (N-acetylcysteine 10–20% solution NEB TID-QID, carbocysteine 375–750 mg PO TID) if ≥2 exacerbations in previous 2 years. Chronic antibiotic therapy generally not recommended


FIFTH LINE

—fourth line plus theophylline 400 mg PO daily × 3 days, then 400–600 mg PO daily, therapeutic level 10–20 μg/mL


SIXTH LINE—

fifth line plus home O 2


SEVENTH LINE

—lung volume reduction surgery (may be beneficial if upper lobe involvement and poor functional capacity) or lung transplant

Canadian Thoracic Society COPD Guidelines 2007

American College of Chest Physicians (CHEST) and

Canadian Thoracic Society (CTS) Joint Guidelines 2014


Treatment Issues



FACTORS FOR IMPENDING INTUBATION

—cardiac or respiratory failure, hemodynamic instability, markedly elevated respiratory rate (>35/min), fatigue and labored respiration, use of accessory muscles, worsening hypercapnia, acidosis (especially lactic), stridor (impending upper airway obstruction), agonal breathing (impending respiratory arrest)


LIFE-PROLONGING MEASURES FOR COPD

—smoking cessation, supplemental O2, lung transplant


INDICATIONS FOR SUPPLEMENTAL HOME O2

—ABG done at room air. PaO2 <55 mmHg alone or PaO2 <60 mmHg in the presence of bilateral ankle edema, cor pulmonale, or hematocrit >56%


Specific Entities



α1-ANTITRYPSIN DEFICIENCY





  • pathophysiology—production of an abnormal protease inhibitor (homozygous ZZ) with impaired transport out of the liver. Serum level is only 10–15% of normal → increased protease activity leads to emphysema and cirrhosis (10%)


  • diagnosis—α1-antitrypsin levels; targeted testing should be considered in patients with COPD diagnosed before 65 years of age or with a smoking history of <20 pack years


  • treatments—similar to COPD, α1-antitrypsin replacement


BRONCHIOLITIS OBLITERANS





  • pathophysiology—severe inflammation of bronchioles → airflow obstruction. Very different from bronchiolitis obliterans organizing pneumonia (BOOP)/cryptogenic organizing pneumonia (COP), a parenchymal lung disorder


  • causes—infection (viral, mycoplasma), inflammatory (ulcerative colitis, rheumatoid arthritis), transplant (bone marrow, lung), toxic fumes, idiopathic


  • treatments—bronchiolitis obliterans (with an organizing intraluminal exudate and proliferative granulation tissue polyp) is usually steroid responsive. Constrictive bronchiolitis (late, fibrotic, concentric) is not responsive to glucocorticoids


BRONCHIECTASIS





  • pathophysiology—airway obstruction, destruction, altered immunity → ↑ cellular and mediator inflammatory response → ↑ elastase, sputum production → recurrent infections → vicious cycle → permanent dilatation of bronchi. Major types of bronchiectasis include



    • cylindrical or tubular bronchiectasis—dilated airways alone, sometimes represents residual effect of pneumonia and may resolve


    • varicose bronchiectasis—focal constrictive areas along the dilated airways


    • saccular or cystic bronchiectasis—most severe form. Progressive dilatation of the airways, resulting in large cysts or saccules


  • causes



    • focal—broncholith, post-infectious, tumor, extrinsic lymph node compression, post-lobar resection, recurrent aspiration


    • diffuse



      • post-infectious—bacterial (Pseudomonas, Haemophilus), mycobacterium, fungal, viral (adenovirus, measles, influenza, HIV)


      • immunodeficiency—cancer, chemotherapy, hypogammaglobulinemia, immunosuppression, sequelae of toxic inhalation or aspiration of foreign body


      • interstitial lung disease—traction bronchiectasis


      • inflammatory—RA, SLE, Sjogren’s syndrome, relapsing polychondritis, IBD


      • inherited—α1-antitrypsin deficiency, cystic fibrosis, primary ciliary dyskinesia (Kartagener’s syndrome, Young’s syndrome), tracheobronchomegaly (Mounier–Kuhn syndrome), cartilage deficiency (Williams–Campbell syndrome), Marfan’s syndrome


  • diagnosis—high-resolution CT chest (signet ring sign), PFT (obstruction ± reversibility)


  • treatments—exercises, chest physiotherapy, and bronchodilators similar to COPD; however, if reversible, inhaled corticosteroids should be given early. Ensure adequate systemic hydration. Effective treatment of exacerbations

NEJM 2002 346:18


Related Topics

Cryptogenic Organizing Pneumonia (p. 18)

Pulmonary Function Tests (p. 25)

Smoking (p. 480)


Pneumonia


NEJM 2002 345:25; NEJM 2001 344:9


Types of Pneumonia



COMMUNITY-ACQUIRED PNEUMONIA





  • bacterial—Streptococcus pneumoniae, Staphylococcus aureus, Haemophilus, Moraxella


  • atypical—Mycoplasma, Chlamydia, Legionella, TB, community-acquired MRSA


  • viral—influenza, parainfluenza, metapneumovirus, RSV, adenovirus


  • fungal—blastomycosis, cryptococcus, histoplasmosis


ASPIRATION PNEUMONIA





  • polybacterial including anaerobes—Bacteroides, Peptostreptococcus, Fusobacterium species and other Gram-positive bacilli


  • chemical pneumonitis


PNEUMONIA IN THE IMMUNOCOMPROMISED

(see p. 291)


NOSOCOMIAL PNEUMONIA

—begins in non-intubated patient within 48 hours of admission





  • polybacterial—Staphylococcus aureus, MRSA, Pseudomonas aeruginosa, Enterobacteriaceae (Klebsiella, Escherichia coli, Serratia), Haemophilus, Acinetobacter


  • viral—influenza


VENTILATOR-ASSOCIATED PNEUMONIA

—begins >48 hours after the patient is intubated (see p. 107)


HEALTHCARE ASSOCIATED PNEUMONIA

—pneumonia that (A) occurs within 90 days of hospitalization of 2 days or more, a stay at nursing home, or a visit to an oral puncture care facility, hospital-based clinic or hemodialysis facility; or (B) occurs within 3 days of receiving antibiotics, chemotherapy, or any type of wound care


Pathophysiology



COMPLICATIONS OF PNEUMONIA





  • pulmonary—ARDS, lung abscess ± cavitary formation, parapneumonic effusion/empyema, pleuritis ± hemorrhage


extrapulmonary

—purulent pericarditis, hyponatremia (from SIADH), sepsis


Clinical Features



RATIONAL CLINICAL EXAMINATION SERIES: DOES THIS PATIENT HAVE COMMUNITY-ACQUIRED PNEUMONIA?





































































 
LR+
LR–

History

Cough
1.8
0.31

Sputum
1.3
0.55

Dyspnea
1.4
0.67

Fever
1.7–2.1
0.59–0.71

Asthma
0.1
3.8

Dementia
3.4
0.94

Immunosuppression
2.2
0.85

Physical

RR >25
1.5–3.4
0.78–0.82

Dullness to percussion
2.2–4.3
0.79–0.93

Decreased breath sounds
2.3–2.5
0.64–0.78

Crackles
1.6–2.7
0.62–0.87

Bronchial breath sounds
3.5
0.9

Egophony
2.0–8.6
0.76–0.96




  • PREDICTION RULE—Diehr model (rhinorrhea = −2 points, sore throat = −1 point, night sweats = +1 point, myalgias = +1 point, sputum all day = +1 point, RR >25 = +2 points, temp ≥37.8 °C [≥100 °F] = +2 points. If score ≥3, LR 14; if ≥1, LR 5.0; if < −1 LR 0.22)


  • APPROACH—“individual or combinations of symptoms and signs have inadequate test characteristics to rule in or rule out the diagnosis of pneumonia. Decision rules that use the presence or absence of several symptoms and signs to modify the probability of pneumonia are available, the simplest of which requires the absence of any vital sign abnormalities to exclude the diagnosis. If diagnostic certainty is required in the management of a patient with suspected pneumonia, then chest radiography (gold standard) should be performed”

JAMA 1997 278:17

Update: The Rational Clinical Examination. McGraw-Hill, 2009


SURFACE LUNG MARKINGS





  • inferior margin of the lungs—level of 6th rib at the mid-clavicular line, level of 8th rib at the mid-axillary line, and level of 10th rib at the mid-scapular line


  • oblique (major) fissures—draw a line diagonally from T3 vertebral body posteriorly to the 6th rib anteriorly


  • horizontal ( minor ) fissure—draw a horizontal line at the level of right anterior 4th rib


Related Topics

Hypoxemia (p. 102)

Parapneumonic Effusion and Empyema (p. 12)

Ventilator-Associated Pneumonia (p. 107)


Investigations



BASIC





  • labs—CBCD, lytes, urea, Cr, troponin/CK, AST, ALT, ALP, bilirubin, urinalysis


  • microbiology—blood C&S, sputum Gram stain/AFB/C&S/fungal, urine C&S


  • imaging—CXR ± CT chest


  • ABG—if respiratory distress, and for PSI if deciding on possible hospitalization


SPECIAL





  • bronchoscopy


  • nasopharyngeal swab—if suspect viral infection, check for influenza A/B, parainfluenza, human metapneumovirus, RSV, adenovirus


  • mycoplasma I gM


  • urine for L egionella antigen


Diagnostic and Prognostic Issues



PNEUMONIA SEVERITY OF ILLNESS (PSI) SCORE





  • scoring—age, female (−10), nursing home (+10), cancer (+30), liver disease (+20), heart failure (+10), CVA (+10), renal failure (+10), altered mental status (+20), RR >30 (+20), SBP <90 mmHg (+20), temp >40°C [>104°F] (+15), HR >125 (+10), pH <7.35 (+30), BUN >10.7 mmol/L [>30 mg/dL] +20, Na <130 mmol/L (+20), glucose >13.9 mmol/L [>250 mg/dL] +10, hematocrit <30% (+10), PaO2 <60 mmHg or O2 saturation <90% on room air (+10), pleural effusion (+10)


  • utility—originally developed as a prognostic tool. Consider admission if PSI score >90. Clinical judgment more important than PSI in determining admission

NEJM 2002 347:25


Management



ACUTE

—ABC, O 2 , IV, consider salbutamol 100 μg MDI 2 puffs q6h + q1h PRN


ANTIBIOTICS



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Mar 26, 2017 | Posted by in GENERAL & FAMILY MEDICINE | Comments Off on Pulmonary Medicine

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