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APPROACH TO A PATIENT WITH ACUTE RESPIRATORY INFECTION
Learning Objectives
• Spectrum• Pathophysiology• Classification• Approach • Clinical syndromes• Case discussion
Impact
• Sixth most common cause of death
• Second biggest cause of DALY(disability adjusted
life years)
• Most common infectious cause of death
• Most common cause of intravenous antibiotic
use in hospitals
ATS Global Scholars program, Pneumonia in children and adults, 2016
ATS Global Scholars program, Pneumonia , in children and adults, 2016
SpectrumRhinitis
Tonsillitis
Sinusitis
Otitis media
Pharyngitis
Epiglottitis
Laryngitis
Tracheitis
Bronchitis
Bronchiolitis
Pneumonia
Pleurisy
Upper respiratory tract infection
Etiology
Rhinovirus(45)Influenza(25)Coronavirus(10)Adenovirus(10)Metapneumovirus(5)Enterovirus(10)RSV(5)
Mandell 8th edition
Acute rhinosinusitis
• Inflammation of nasal cavity and sinuses• <4 weeks
Symptoms Suggesting Bacterial InfectionProlonged symptoms (> 10 days)Unilateral maxillary sinus tendernessUnilateral purulent nasal dischargeDouble sickening (symptoms improve then worsen)
Chow et al. Clin Infect Dis. 2012; 54(8):e72-112
Acute Pharyngitis
Sudden onset
High fever
Lymph nodes
Treatment: Penicillin V 500mg BD x 10 days or Amoxicillin 1000mg OD x 10 days
Influenza virus
Pneumonia
• Inflammation of the pulmonary parenchyma plus clinical evidence that the infiltrate is of an infectious origin, which include new onset of – Fever(< 7 days)– Purulent sputum– Leukocytosis – Decline in oxygenation
ATS 2005 HAP/VAP Guildelines
Classification
•Viral•Bacterial•FungalEtiological
•Lobar•Broncho•Interstitial
Morphological
•Community acquired•Hospital Acquired•Ventilator acquired
Clinical syndrome
Epidemiological triad
AgeNormal floraGlottis reflexImmunityEpithelial sheddingMucociliary clearance
Condition OrganismIn almost all cases Strep and H. influenzae are predisposed as they are most common.In Indian settings, most conditions also pre dispose to Tuberculosis
Bat exposures, Bird droppings Histoplasma, Cryptococcus
Paddy fields, farmers, rodent exposure Leptospira
Hilly areas(Himalyan belt) Scrub typhus
Birds Chlamydia psittaci
Farm animals Q fever(Coxiella)
North America travel
Aspiration risk/Alcohol Anaerobes
Structural lung disease Pseudomonas, Burkholderia, NTM, fungal
Injection drug users Staphylococcus, Anaerboes
Influenza outbreak Influenza, Staphylococcus
Air conditioners, cooling towers, pot water
Leigionella
COPD Moraxella, Pseudomonas
Fishmans Pulmonary Medicine 5th edition
Physical examination• Respiratory system examination– Respiratory rate– Bronchial sounds, dullness to percussion, crackles
• Additional exam– Cutaneous abscess– Skin lesions– Lymph nodes– Periodontal hygiene– Gag reflex– Ear examination
Investigations
NONINVASIVE
INVASIVE
Hematological
1. CBC with DLC
2. KFT3. LFT4. Biomarkers
Microbiology
1. Sputum2. Nasal Swab3. Blood
cultures4. ET aspirate5. Newer test
Radiology1. Chest X-ray2. CT scan
1. Bronchoscopy2. Lung Biopsy
Biomarkers
• Erythrocyte sedimentation rate(ESR)• C- Reactive Protein(CRP)• Procalcitonin(PCT)• Trigerring receptor expressed on Myeloid
cells(sTREM1)
Procalcitonin• Precursor of calcitonin – Thyroid and K cells of lung• CAP – Only role may be to differentiate from decompensated
heart failure and non infective causes• HAP/VAP – Not used for diagnosis and initiation of antibiotics
but clinical as well as Procalcitonin may be used to stop antibiotics
• Sequential use of Procalcitonin for levels maybe useful
Sensitivity Specificity False Positive False negative
67% 83% 33% 17%
Negative Positive Sepsis Severe sepsis<0.05ng/ml >0.5ng/ml >2 ng/ml > 5 ng/ml
Gilbert N. D. , Procalcitonin in Respiratory Tract Infections d CID 2011:52 S347
Kidney dysfunction??
Sputum examination
• Collection– Morning before breakfast– Induced or spontaneous– Deep breath– Direct into container
• Adequacy– <10 squamous ep. Cells/lpf– >25 or more PMNL/lpf
• ProcessingWashington Murray grading system
• Stains– Gram stain– Ziehl-Neelsen(AFB**)– Fungal wet mount(KOH)– Giemsa
• Culture (Agar)– Blood – Mac Conkey – Chocolate
Culture methods
Quantitative Semi- Quantitative
In terms of cfu/mlCut offs1. Sputum – 105-106
2. ET aspirate – 105-106
3. Mini Bal – 103-104
4. BAL – 103-104
5. PSB - >103
Types1. 1+ 2+ 3+ 4+ 2. Rare /Light /Mod
/Heavy
Moderate or 3+ areconsidered significant
Ref
Newer tests• Urinary Antigen – Streptococcus(X) and Gp 1 Legionella (Room 2079)– Sensitivity – 75%, Specificity - >95%– Early(<15 min), no effect with antibiotics
• Serological tests(Anaerobe lab)– IgM for Chlamydia and Mycoplasma
• Molecular diagnostics– Sensitive but no resistance pattern and costly(X)
Radiological tests
• Chest X ray – 75% sensitivity– Lateral view
• CT scan – Gold standard– Definite indications – fungal, unclear CXR, COPD
patient, non resolving pneumonia
Radiological classification
• Alveolar pneumonia• Bronchopneumonia• Interstitial pneumonia
Common X-rays
CT(Computed tomography) scan
Lung Ultrasound
• Sensitivity – 60-90%, Specificity – >90%• Advantages– Radiation free, bedside and quick – Pregnant women– Dynamic evaluation
• Appearence– Serrated margins with hepatization– Air bronchogram(dynamic)– Pleural shred sign
Chaves MA et al. , Lung ultrasound for the diagnosis of pneumonia in adults: Respir Res 2014; 15:50
Flexible Bronchoscopy• Endoscopic procedure to visualise
tracheobronchial tree• Various specimens:– Bronchial brush– Bronchial washing– Bronchoalveolar lavage(BAL)– Endobronchial biopsy– Transbronchial(TB) lung biopsy– TB needle aspiration– Endobronchial ultrasound
Other samples
ET aspirate**
•Non invasive•No special equipment required
Mini BAL(mBAL)
•Advantage: Possible bedside, cheaper •Disadv: Blind procedure
PSB•Newer technique•Less chances of contamination
ET- EndotrachealPSB – Protected specimen brush
Clinical syndromes
• Community Acquired pneumonia– Typical and atypical
• Hospital acquired pneumonia• Ventilator acquired pneumonia
• Health care associated pneumonia
Community Acquired Pneumonia
LRTI mortality Tuberculosis Infectious diseases0
50
100
150
200
250
Mortality per year /1,00,000 people
Etiology
Gupta D et al. Guidelines for diagnosis and management of community-and hospital-acquired pneumonia in adults: Joint ICS/NCCP(I) recommendations. Lung India. 2012
Streptoco
ccus(3
-51)
Mycoplas
ma(4-24)
Chlamyd
ia(2-23)
H. Influenzae
(5-21)
Viruses(1
0-36)
Leigi
onella(1-6)
Staphylo
coccu
s(1-2)
0
10
20
30
40
50
6040-71% had a microbiological diagnosis
B. A. Cunha et al. Clin Microbiol Infect 2006; 12 (Suppl. 3): 12–24
Atypical pneumonia
• Walking pneumonia• Difference: – Systemic manifestations**– Minimal sputum – Sub acute progression– Chest X ray pattern – Fever and leukocytosis less common
• Mycoplasma(25%), Chlamydia(12-21%), Legionella, Q fever
Admission decisionCURB 65(BTS)
Confusion
Urea(>20mg/dL)
Respiratory rate >30
Blood pressure <90 systolic ; or < 60 diastolicAge>65 years
Pneumonia Severity IndexGenderDemographyCo morbiditiesPhysical examinationLab and radiographic findingsScored in points I – 0-50II – 51-70 III – 71-90IV – 91-130V – 131-395
Fine MJ et al. N Engl J Med. 1997;336:243-250.Capelastegui A et al. Eur Respir J. 2006;27:151-157
Each gets one point
BTS – British Thoracic society
Severity AssessmentPneumonia
Severity Index30 day mortality(%)
CURB-65 30 day mortality(%)
Where to manage?
I 0.1 0 0.7 Outpatient
II 0.6 1 2.1 Outpatient
III 0.9 2 9.2 Inpatient(Short observation)
IV 9.3 3 15 Inpatient
V 27 4 40 Inpatient-ICU
Fine MJ et al. N Engl J Med. 1997;336:243-250.Capelastegui A et al. Eur Respir J. 2006;27:151-157
Physicians decision
IDSA 2007 severity assessment
1 MAJOROR
3 MINOR
ICU/HDU
IDSA/ATS Guidelines for CAP in Adults, Mandell A. L et al CID 2007:44 (Suppl 2)
TreatmentClinical Profile Antibiotic
Outpatient
Previously healthy and no antibiotic in last 90 days
Macrolide(Aithromycin/Clarithromycin/Erythromycin) OR Doxycycline
Comorbidity or antibiotic in 90 days Respiratory Fluoroquinolone(Gemifloxacin/Moxifloxacin/ Levofloacin)Or β-lactam + macrolide
Inpatient
Non ICU Same as above
ICU admission β-lactam + Fluoroquinolone/AzithromycinOr Aztreonam + Fluoroquinolone
ICU with ? Pseudomonas Antipneumococcal, antipseudomonal β-lactam plus Ciprofloxacin/LevofloxacinOr Aminoglycoside + Azithromycin
ATS/IDSA Guidelines 2007
Clinical response of pneumonia
Pneumonia
Tachycardia and hypotension
Fever, tachypnea and arterial oxygenation
Cough and fatigue
Radiological resolution
2 days
3 days
14 days
3-4 weeks
Highly variable1. Co morbidity2. Age3. Severity
Marrie TJ, et al. Resolution of symptoms in CAP on ambulatory basis, J Infect 2004; 49:302
Other considerations
• Role of steroids
• IV to oral shifting
• Duration of antibiotics
1.No role in non severe(2A)2. Role in severe CAP with severe inflammation(CRP>15mg/dL), septic shock or ARDS2. Mortality risk reduction3. Contraindications to be ruled out4. Dose regimen
5-7 days, if MRSA/Leigionella/ pneumococcal sepsis; may require for longer time, but clinical stability and 48-72 hours afebrile
Patient is cinically better
ATS 2007 Guidelines and 2012 Lung India guidelines
Non community acquired
Hospital acquired Ventilator associated
Non - ICU ICU Early Late(>4)
48 48-72
Healthcare associated pneumonia • Hospitalization for more than 48 hours in the last 90 days• residence in a nursing home or extended care facility• home infusion therapy• chronic dialysis within one month• home wound care• a family member with a multi-drug resistant organism.
Controversy
Next guidelines of CAP will likely include it
ATS /IDSA HAP/VAP Guidelines 2005
EtiologyIncidence of VAP is much higher in developing countries
Study at AIIMS, 478 BAL samples tested, 192(40%) showed isolates
Ritu Singhal, Srujana Mohanty. Profile of bacterial isolates from patients with VAP. Indian J Med Res 121, January 2005, pp 63-64Khilnani GC, Jain N. Ventilator-Associated pneumonia. Indian J Crit Care Med 2013;17:331-2.
Organism NumberAcinetobacter 86(44.8%)
Psudomonas 77(40.1%)
Others- E. Coli 8(4.2%) ; Citrobater 4(2.1%) ; Enterobacter – 3(1.6%)
Staph. Aureus 2 (1.1%)
Diagnosis of HAP/VAPRadiology Sign/Symptoms/Lab
2 or more serial X-rays with at least one of the following: 1. New or Progressive and persistent infiltrates2. Consolidation3. Cavitation
At least one :1. Fever2. Leukopenia or leucocytosis3. If age>70; altered mental statusAt least 2 of the following:1. Sputum ( new onset/ change in
character) or increased secretions increased suctioning requirement
2. Worsening gas exchange(desaturation/increased oxygen requirement/ increased ventilatory requirements)
3. New onset dyspnea/cough/tachypnea4. Rales or bronchial breath sounds
2013 CDC definitions for Healthcare associated infections
At least 2/3Persistent infiltrates
+1. Leucocytosis
2. Change in oxygen/ventilatory requirement
3. Secretions
Risk factors for MDR VAP 1. Prior antibiotic use in 90 days
2. Septic shock at time of VAP
3. ARDS preceding VAP
4. >5 days of admission before VAP
6. Dialysis before VAP
Risk factors for MDR HAP/MRSA or MDR Pseudomonas in HAP or VAP
Injectable antibiotic use in last 90 days
Risk of death in HAP1. Ventilatory support2. Septic shock
ATS Guidelines for HAP/VAP Management, 2016
ATS/IDSA Guidelines for HAP/VAP 2016
7
Prevention of VAP
Nancy Munro et al. Ventilator-Associated Pneumonia Bundle, AACN 2014 Vol 25 175-183
Changes in 2016 guidelines
• Removal of HCAP
• Equal efficacy of non invasive sampling(like endotracheal aspirate) and semiquantitative culture
• Systemic colistin used only with inhaled colistin
• Use dual antibiotics(for Pseudomonas) even after culture if patient has septic shock or high risk of death.
Fungal pneumonia• Mortality – 50-90%• Structural lung disease• Risk factors:
• Broad spectrum antibiotics• TPN, Central catheters• Prolonged ICU stay• Renal/hepatic dysfunction• Large BT requirements
• Leading causes –Aspergillus, Mucor, Candida• Endemic fungi(Cryptococcus, Histoplasma etc)
Pneumocystis jiroveci(PJP)
• Immunocompromised • (A-a) gradient• Induced sputum (Variable), BAL(90% yield)• Treatment needs to be started empirically• Treatment – 15-20mg/kg/day of
Cotrimoxazole QID (2tab DS TDS) x 21 days• Steroids-PaO2<70, A-a gradient>35, hypoxia
Aspergillus
ABPA
• Refractory asthma
• Mucus plugs
• NOT A TRUE INFECTION
Aspergilloma
• Patients withprior co morbidities
• Sub acute pneumonia with constitutional symptoms
CNPA
• History of disease suggestive of cavity ?TB
• Asymptomatic or hemoptysis
• Rarely fever
Invasive Aspergillosis
• Immunocompromised patients
• Rapidly progressive pneumonia
ABPA- Allergic bronchopulmonary aspergillosisCNPA- Chronic Necrotizing Pulmonary Aspergillosis
• Specific criteria
• Fleeting opacities, HAM
• Treat with steroids and if reuired Itraconazole
• Chest X ray and CT shows cavity with soft tissue density
• Itraconazole, inhaled KTZ
• Other antifungals
• Tissue and sputum needs to demonstrate Aspergillus (GMS stain)
• Serial Galactomannan monitoring
• CT signs – Halo sign • DOC- Voriconazole
ABPA Aspergilloma CNPA Invasive Aspergillosis
ParasiticFocal
Consolidation
Paragonimus
Cystic
Entamoeba
Coin lesion
Dirofilaria
Diffuse
Transient(Loeffler’s)
Hookworm
Roundworm
Alveolar
Schistosoma
Strongyloides
Tropical Pulmonary
eosinophilia
Mycobacteria
• As community acquired pneumonia 3-16% but even as high as 30%
• Fluoroquinolones – Do not use as earlly resistance(5-10 days)
• Clues – Endemic, co morbidities, pleural effusion, chronicity of symptoms, upper lobe, cavity, norrmal TLC
L.M. Pinto et al. / Respiratory Medicine (2011) 138e140R.F. Grossman et al. / International Journal of Infectious Diseases 18 (2014) 14–21
TAKE HOME MESSAGES
• Investigate in a planned way• Know the interpretation• Lung USG is a must
• “Pneumonia” or “LRTI” is not the complete diagnosis
• Evidence based management and de escalation
• Never forget “TB” and avoid Levofloxacin