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Respiratory Infections. Caroline Kowal Preceptor: Dr. Rhonda Ness Core Rounds Dec 11, 2003. Objectives. Alberta Clinical Practice Guidelines Community Acquired Pneumonia Adult/Child Nursing home acquired Pneumonia Immunocompromised Alcoholics. Guidelines not prospectively validated
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Respiratory Infections Caroline Kowal Preceptor: Dr. Rhonda Ness Core Rounds Dec 11, 2003
Objectives • Alberta Clinical Practice Guidelines • Community Acquired Pneumonia Adult/Child • Nursing home acquired Pneumonia • Immunocompromised • Alcoholics
Guidelines not prospectively validated • Prior studies of pneumonia guidelines have reported: • decreased lengths of stay, admission rates, and costs • no change in clinical outcomes.
Definitions • Community Acquired Pneumonia (CAP) – Pneumonia in pt not hospitalized last 14d, OR hospitalized <4d prior to onset sx Adult - >16 y age
Community Acquired PneumoniaAdults Incidence: • #1 cause of infectious related deaths • #6 cause of death overall • 12/1000 adults (US stats) • 80% outpt tx • Mortality <1% for outpt, 14% for admitted • 50% pneumonia cases and 90% mortality in pt >65 years age
2-27% (50% APG) CAP is S.pneumoniae • Risk factors for resistant S.pneumo: • Beta-lactam/quinolone i.e.cipro/macrolide use in last 3 months • EToH • >65 y.o. • Immunosupressed • Exposure to children in childcare facility • Resident of long term care facility • Worry if it is a highly resistant S.pneumo (invasive) 7% or 27% pt • Outpt DO NOT need antimircobial activity against highly resistant S.pneumo. Use macrolides or B lactam monotx
Mycoplasma pneumonia 20% CAP (esp younger) • Chlamydia pneumoniae 10% CAP and may be co-pathogen in elderly • Influenza A and B, parainfluenza, adenovirus in 2-15% CAP • 20% cases TB in residents of long term care facilities (20-30X increased risk TB)
Presentation • In elderly, may not have classic S&S, may be afebrile. May present with delerium/confusion (44.5% pneumonia pt) • RR> 25 has sensitivity 90% and specificity of 95% for dx pneumonia • Single temp 38.3 C has sens 40% (37.8C has sens 70%)
Investigations • Blood culture only if pt has hx of chills/rigors • Blood culture within 24h presentation associated with a decreased 30d mortality in CAP (Meehan, TP, et al. Quality of care, process, and outcomes in elderly patients with pneumonia JAMA 1997;278:2080-2084) • Do 3 sets: • 1aerobic/1 anaerobic • 1 aerobic from 2nd site at same time
Blood culture evidence? • Mortality rate from bacteremic pneumococcal CAP has shown little improvement in the past three decades, remaining between 19% and 28%, (depending on the population and institution studied) • Helpful in 15% pt
Blood gases • SaO2 <90% or pt has COPD take ABG on room air or baseline 02 level if on chronic O2 therapy • Thoracentesis if effusion >10mm on lateral XR • Recurrent pneumonia – need w/u for immunosupression or structural abN
Gram stain • Adequate if < 25 epithelial cells per low-powered field • >10 gram-positive, lancet-shape diplococci in a hpf is a sensitive and specific predictor of pneumococcal pneumonia • Gram stain not helpful for other types pneumonia • NPV 80%
Fine et al. Prediction Rule to identify low risk pt with CAP. NEJM 1997;336:243 • 14, 199 adult in pt with CAP • 5 classes of risk of death in 30d • Validated with 38.039 in pt • PORT cohort 2287 in and outpt • Detemined 20 factors independently related to mortality in an additive fashion • Limits: • Medical/psychosocial C/I • Immunosuppressed • May oversimplify, clinical judgement NB • No SaO2 in class I
PORT Score • Risk classes 1 (lowest) to 5 (highest) • Class 1 -2 younger pt (35 – 59y) • Class 3 -5 older pt (72- 79y) • Based also on comorbidities, abnormal physical findings, lab values • Outpt mx for class 1 and 2 • Brief in pt observation class 3 • Admission class 4 and 5
PORT score Hypotension (SBP < 90, DBP < 60) Tachypnea Low sats Elevated BUN (>20) or Cr > 120 Altered LOC WBC <4 or >30 ANC <1 Elevated PT or PTT Low plts Multilobar involvement Cavitation Rapid spreading Who to admit?
Who goes to ICU?American Thoracic Society Guidelines • RR > 30 • Severe Respiratory Failure (PaO2/FiO2 <250) • Ventilated • Bilateral infiltrates or multilobar • Shock • Vasopressors • Oliguria (<20cc/h) • Presence of one factor 98% sens, 32% specific
Management CAP • Hydration • Wt loss >5-10% associated w increased mortality • Abx to cover S.pneumo, M.pneumo, C.pneumo • 1st choice macrolide or doxycycline • Macrolide resistance for S.pneumo ~10% and may have suboptimal coverage for H. influenzae . . . Avoid in pt with chills/rigors • Floroquinolones – use for failed first line tx or for elderly with significant comorbidity • BIPAP (Dean et al. Chest 2000)
Which antibiotics and why?To“Risk stratify” and “Drug stratify” • Increasing evidence that pneumococcus needs double coverage • BASICS TO COVER FOR ALL CAP: • S.pneumo, H.flu, M.catarrhalis are principal bugs (B LACTAM) • Atypicals include Mycoplasma, Legionella, and C. pneumoniae (MACROLIDE)
Inpatient Mx • Cephalosporin iv (i.e., ceftriaxone, cefotaxime, etc.) with significant activity againstS. pneumoniae, H. influenzae, and M. catarrhalis PLUS • Macrolide iv to provide activity against atypical organisms
Cipro NOT for CAP • Inadequate coverage S.pneumo • Hydrophilic molecule as opposed to hydophobic molecules of other quinolones • Activates efflux pumps which may be initial step in quinolone resistance • Chen et al found that the prevalence of ciprofloxacin-resistant pneumococci (MIC ≥ 4 mcg/mL) increased from 0% in 1993 to 3.7% in 1998 • Combination of reduced susceptibility and increased resistance! • Floroquinolones (levo) monotx in critically ill has not been established (but likely would work as covers gm +, gm - , atypicals and some anaerobes) Chen D, McGeer A, de Azavedo JC, et al and The Canadian Bacterial SurveillanceNetwork. Decreased susceptibility of Streptococcus pneumoniae tofluoroquinolones in Canada. N Engl J Med 1999;341:233-239.
When to use “Vitamin L” • Floroquinolones (levofloxacin, gatifloxacin, moxifloxacin) • Reserved for selected pts with: (CDC-DRSPWG) • Inpt who failed ceftriaxone + macrolide • Allergic 1st line agents • Documented infection with highly resistant S.Pneumo (penicillin MIC 4 mcg/ml)
Abx coverage • 1st gen cephalosporins – gm (+) • 2nd gen cephalosporing - Cefoxitin, cefotetan, and cefmetazole, provide coverage against Bacteroides • 3rd gen cephalosporins – more gm (–) rod coverage • Ceftazidime for Pseudomonas • Imipenem has broad coverage against aerobic and anaerobic organisms. • Aztreonam good for gm (-) bacilli such as Pseudomonas Clindamycin, Metronidazole - anaerobes, e.g. B. fragilis.
S.Pneumo Resistance Capital Health Region • Penicillin 15.8% • Amoxicillin 4.7% • Cefuroxime 9.8% • Cefotaxime/ceftriaxone 3.9% • Macrolide 13% • TMP-SMX 21% • Levofloxacin <1% • Vancomycin 0%
S.Pneumo % Sensitivity Antibiotogram CalgaryCommunity vs Nursing Home vs PLC vs FMCvs RVG • Penicillin 87%, 100%, 73%, 95%, 85% • Amoxil 100%,100%,100%,100%,100% • Ceftiaxone 100%,100%,100%,100%,94% • Erythro 60%, 100%, 60%, 84%, 66% • SXT 60%, 100%, 60%, 75%, 51% July 1, 2001 – June 30, 2002
S. pneumoniae with penicillinresistancealso has resistance to (all on same gene): • Macrolides • Augementin • TMP-SMX • 2nd and 3rd generation cephalosporins • No resistance to vancomycin or quinolones • Various levels of resistance (minimal with cephalosporins, may be intermediate with macrolides)
BUT . . . Greatest growth in resistance is to floroquinolones • Greatest risk for emergent resistance during tx and resultant tx failures so also has largest increased tx duration because of resistance and big decrease clinical response to emerging infections • Risk factors for resistance to floroquinolones: • >64y.o • COPD • Past fluoroquinolone use
Is Resistant S.pneumo clincially significant? • Tx failures reported with AOM and meningitis • Relationship with resistance and pneumococcal pneumonia unclear • *Ceftriaxone (1 g/day iv) or cefotaxime (1.5-2 g/8 h iv) work well in adult patients with systemic nonmeningeal pneumococcal infections caused by strains with ceftriaxone/cefotaxime MIC up to 1 mcg/mL (or even 2mcg/ml) • 429 episodes CAP correlated the ceftriaxone/cefotaxime MICs and antibiotic therapy with 30 d mortality rate • In 185 episodes treated with 1 g/d of ceftriaxone (n = 171) or 1.5-2 g/8 h of cefotaxime (n = 14) • 18% (26/148) sensitive strain mortality rate • 13% (3/24) intermediate resistant strain mortatlity rate • 15% (2/13) resistant strain mortality rate • respectively (P = 0.81) * Pallares R, Capdevila O, Liñares J, et al. Hospital Bellvitge, University of Barcelona, Spain; Clinical Relevance of Current NCCLS Ceftriaxone/Cefotaxime Resistance Breakpoints in non-Meningeal Pneumococcal Infections. Abstract Poster, 2001.
Elderly and CAP • Susceptible gm (-) enteric organisms such as: • Klebsiella • Escherichia coli • Pseudomonas • Increased risk infection with DRSP • Need macrolide + cephalosporin or fluoroquinolone
Risk Factors for DRSP or atypical pathogens in the Elderly 1) Increasing fragility (> 85 years of age, comorbid conditions, previous infection, etc.) of the patient 2) Acquisition of the pneumonia in a skilled nursing facility 3) Presence of an aspiration pneumonia, suggesting gram (-) or anaerobics 4) Chronic alcoholism (Klebsiella pneumoniae) 5) Pneumococcal pneumonia in pt with comorbidities and no Pneumovax vaccine 6) Hx of infection with gram (-), anaerobic, or resistant species of S. pneumoniae 7) Hx of treatment failure 8) Previous hospitalizations for pneumonia 9) Previous ICU hospitalization for pneumonia 10) Caught pneumonia in area with known DRSP 11) Immunodeficiency and/or severe underlying disease.
Admission Criteria • Pneumonia Severity of Illness score • Give abx within 8 hours of arrival to hospital (decreases mortality)
Poor Outcome Risk Factors • RR > 30 • SBP <90, DBP <60 • ARF • Malnourished or >5% wt loss in past month • Functional impairment • Age/comorbid conditions
. • Numerous studies showing that pneumonia guidelines can reduce mortality and reduce unnecessary use of resources
Case AJ: 11yo male • N/V/D x 1 day • 6x vomitting, 2x diarrhea • Periumbilical abdo pain • “Dizzy” • Rhinitis, cough • 38C, HR 117, RR 28, 105/75, 96% RA
AJ’s Exam • Pale • Small cervical nodes • Abdo exam nontender • No indrawing • Decreased breath sounds RLL, crackles
Pediatric CAP • Bronchopneumonia – acute inflammation smaller bronchial tubes and peribronchiolar alveoli • Pneumonitis Syndrome – Infants 1 – 3 months old, afebrile with cough, tachypnea and progressive respiratory distress. • CXR shows diffuse pulmonary infiltrates and air trapping • Single or mutlipathogens involved
Incidence • 35-45/1000 kids <5 y.o. • 16-20/1000 in 5 - 9 y.o. • 6-12/1000 >9 y.o. • No specific cause of pneumonia identified in 40-60% cases
Age best predictor for the offending BUG • As we all know, VIRUSES #1 age 1month to 2 years • RSV 50% • Parainfluenza 25% • Small number influenza A, B and adenovirus
Neonatal Period GBS Listeria E.coli Infants 1 – 3 months Usu have pneumonitis syndrome Chlamydia trachomatis Bordetella pertussis RSV 3 months – 2 years Usu viral S.pneumo Non typable H.flu M.catarrhalis Mycoplasma pneumonia C.pneumonia Increasing incidence C.Pneumonia (1-15%) **Hib vacccine offers no protection against NTHI**
2-5 yr Viral S.pneumo H.flu (Hib) Nontypable H.flu M.pneumoniae C.pneumoniae 6-18 yr M.pneumoniae S.pneumo C.pneumo NTHI Influenza A and B Adenovirus
Bugs that get you into the ICU • All ages: • S.pneumo • Staph • GAS • Hib • M.pneumoniae • Adenovirus • RSV
C & M pneumoniae • C.pneumo 15-18% PCAP aged 3-12 • Most asx • Only 10% cases result in clinically apparent pneumonia • Fever, malaise, headache, pharyngitis • Some authors state wheezing more common with viral and C & M pneumoniae • ? Increased incidence conjunctivitis
Risk Factors • Recent URTI • Exposure to cigarette smoke • Daycare • Prematurity (up to 1 year) • Malnutrition • Recent hospitalization (last 3 months) • Immunocompromised, cardiopulm or neurologic disorders • Low socioeconomic status • Cystic fibrosis
2 classic presentations • Typical: fever, chills, pleuritic chest pain, productive cough • Atypical: gradual onset over days to weeks, domination of sx of h/a and malaise, nonproductive cough, low grade fever
Fever, rigors, pleuritic chest/abdominal pain suggest pneumococcal pneumonia • Temp >38.5C • RR >50/min in <11 months • RR >40/min in >11 months • RR >28 in 5 -16 years
What makes you suspicious of pneumonia vs the good ol’ virus? • Absence of sx cluster of: • Resp distress • Tachypnea • Crackles • Decreased breath sounds excludes pneumonia • 100% specificity (level II) Based on Lethenthal’s paper: 133 pt aged 3 mo – 15y (26+ pneumonia)
Symptom Tachypnea Cough Toxic Crackles Retractions Flaring Pallor Grunting Sn Sp 92% 15% 92% 19% 81% 60% 44% 80% 35% 82% 35% 82% 35% 87% 19% 94% Sn and Sp of Sx to IC PCAPLeventhal. Clinical predictors of pneumonia as a guide to ordering chest roetgenograms. Clin Pediatr 1982; 21:730-734. Findings most sens for predicting infiltrates – tachypnea, cough, toxic look Findings most spec for + infiltrate – flaring, pallor, grunting