pneumonia

Hey all,

Here are some notes from a recent morning report on pneumonia. Enjoy!
 

Diagnosis:

·       Hallmark symptoms are cough, fever, sputum production, pleuritic chest pain

·       Physical exam described by Laennec (1819, inventor of stethoscope, died of TB which was diagnosed by nephew with Laennec’s stethoscope)

·       Findings: cachexia (LR 4), vital signs normal (LR .3), asymmetrical chest expansion (LR 44), dullness (LR 3), bronchial sounds (LR 3.3), egophany (LR 4.1)

·       CXR imaging required; pulse oximetry helpful

·       Remember classic lobar, typical bug vs. interstitial, atypical bug is not really useful

·       Can search for microbe with following tests if it will change abx coverage or will likely be positive: blood cultures (+ 10%), sputum culture (14 % useful in all comers, a good sample has < 10 squamous cells / LPF), legionella urine antigen (serogroup 1), pneumococcus urine antigen (70 % sens, > 90 % spec), np swab (60 % sen, 100 % spec), bronchoscopy: consider if immunosuppressed, critically ill, non-responders

Who needs admission/ CURB-65:

·       CURB 65 from Lim W et al, thorax, 2003 (excluded NH residents)

·       Confusion (disorientation to person, place, time), uremia > 7, RR greater or equal to 30, BP < 90 / <=60, age 65 or older.

·       30 day mortality: 0 = .7 %, 1 = 2.1%, 2 = 9.2 %, 3 = 14.5 %, 4 = 40%, 5 = 57%

·       Generally 0,1 for outpt rx; 2s to ward; 3 + to ICU

·       Pneumonia severity index (PSI) stratifies into 5 mortality levels, 3-5s need admission, maybe a bit better at ruling in low risk patients but need !20! variables

·       Remember scores are only a guide, need to consider comorbidities, ability to take meds, hypoxia

Bugs:

·       Strep pneumonia, Haemophilus influenza, Moraxella catarrhalis, staph aureus

·       Atypicals (not on stain): Mycoplasma pneumonia, Chlamydophila pneumonia, legionella species

·       Viruses: A/B influenza, adenovirus, parainfluenza, RSV

·       Anaerobes: only if frank aspiration +- patients with gingival disease

Fun scenarios:

·       Bat/bird droppings: histoplasmosis

·       Exposure to rabbits: F. tularensis

·       HIV/ AIDS: PCP, MAC, histoplasmosis, Cryptococcus and all else

·       Bronchiectasis: pseudomonas, staph, burkholderia cepacia

·       Cough > 2 weeks with whoop or post-tussive vomiting: bordetella pertussis; children or adults with waning immunity

·       Hotel + cruise ship: legionella (from central AC,water towers), first outbreak at legionnaires conference, Philadelphia, 1976

·       Bioterrorism: bacillus anthracis, Yersinia pestis (plague), francisella tularensis (tularemia)

Empirical therapy

·       Outpt / healthy / no abx last 3 months : Macrolide, doxycycline

·       R.Fs for macrolide resistant pneumococcus: old age, recent abx in 3 mos, medical comorbidities, alcoholic, immunosuppressed

·       Outpt / comorbidities / abx in last 3 months (use diff class): resp. FQ or B-lactam + macrolide

·       Inpt/ non-icu: resp FQ or B lactam + macrolide (better survival v. only macrolide)

·       Inpt/ icu: B lactam (3^rd gen cephalosporin) + [macrolide or resp FQ), better survival with double pneumococcus coverage in some studies in really sick pts

·       If worried about pseudomonas i.e alcoholic, frequent abx: use B lactam (that covers pseudomonas and pneumococcus = tazocin, carbapenems, cefipime) + FQ

·       If MRSA: add vanco or linezolid

·       If viral pneumonia: early treatment (within 48 hrs) with oseltamivir, zanamivir recommended by both IDSA + Canadian guidelines, may reduce shedding after 48 hr. N.B remember you can check Ontario respiratory virus bulletin for information about was occurring.

Controversy

·       Cochrane review conducted on antivirals for influenza found lots of problems with data

·       Over 60% of data from phase 3 trials never published, much of it withheld by drug makers

·       42 of 67 studies not used because of discrepancies in data like not including serious adverse events

·       Found antivirals shortened symptom duration by 21 hrs

Management considerations:

·       May not be improving because insufficient time, insufficient dose, resistant bug, wrong diagnosis, metastatic infection (endocarditis, meningitis)

·       Switch to oral therapy when improving, able to tolerate PO, and stable

·       Treat for minimum of 5 days, as long as afebrile for 48-72 hrs + stable

·       Halm E et al Arch Intern Med assessed stability for d/c by using 7 RFs: Temp, HR, RR, sBP, oxygenation, PO intake, mental status. If 2 or more markers at d/c, higher rate of mortality, readmission, any adverse event (OR 7.4)

Hospital acquired pneumonia / healthcare associated pneumonia:

·       Who: Hospitalization within 90 days, NH, home wound care or infusions, dialysis etc.

·       Bugs: gram negative bacilli

·       Drugs: (antipseudomonal drug, PCN, cephalosporin, carbapenem) + FQ + MRSA drug