Ventilator Associated Pneumonia: New for 2008

Transcription

1 Ventilator Associated Pneumonia: New for 2008 Jeanine P. Wiener-Kronish, MD Henry Isaiah Dorr Professor of Research and Teaching in Anaesthetics and Anaesthesia Department of Anesthesia and Critical Care Anesthetist-in-Chief Massachusetts General Hospital

2 Objectives for Talk Endotracheal tubes are a conduit from the mouth to the lung What is an infection in a organ filled with bacteria Ideas regarding management

3 TAKE HOME POINTS We do not have optimal dx tests or gold standard for VAP Therefore it should not be used as a quality measure Always use gloves and use alcohol based soaps before and after examining each patient Patients should be extubated as quickly as possible--daily wake-up from sedation-- consider daily weaning trials/ non-invasive ventilation Consider quantitative cultures as a method of discontinuing un-necessary tx

4 VAP-Wrong Benchmark No consensus as to clinical dx CDC criteria is very subjective Difficult to modify hospital processes and eliminate VAP ATS, SCCM, ACCP will be coming out with letter protesting VAP as a benchmark Klompas M Ann Intern Med 2007;147:803-5

5 The Major Issues Antibiotic treatment of ventilator associated pneumonia( VAP) has to be early and appropriate to improve patient outcomes ~30% of intubated patients develop VAP Fifty percent of ICU patients receive broadspectrum antibiotics, for VAP. This practice has contributed to a crisis of increasing antibiotic resistance in pathogenic bacteria Antibiotic resistance is like second-hand smoke in the ICU

6 Antibiotic Tx Failure to start appropriate antibiotic treatmentincreased costs, increased healthcare utilization, increased morbidity and mortality Unnecessary administration of antibiotics-- increased costs, increased risks for adverse drug reactions, selection of resistant microbial flora, poorer outcomes Use of antibiotics alters ecology in ICU--increases cross-colonization and increases infections with resistant pathogens in ICU [Affects study design] Lisboa Curr Opin Infect Dis 2008;21: Hurley J Antimicrobial Chemotherapy Epub ahead March 8, 2008

7 Antibiotic Resistance Netherlands, Canada, Scandinavia do not have increasing antibiotic resistance. Strict isolation and restricted antibiotic administration appears to help control resistance.

8 Conclusion for Introduction What objective data identify the intubated patients that are truly infected? Goal should be both to treat people who are infected and not to treat people who do not need antibiotics

9 Definitions

10 Infection vs Colonization Infection -Finding bacteria in a normally sterile environment; Defined as a decrease in host fitness; the patient has sustained some decrement in organ function due to bacterial-induced injury Colonization - bacterial present but no decrement in organ function

11 Evaluation of ET tube Colonization Evaluated 10 healthy men (mean age 35) intubated for trauma 9/10 colonized within 12h with rapid increase in numbers of bacteria over 24h and peak at 96h Organisms in lung come from oropharynx and gut Feldman- Eur Resp J 1999;13:

12 Evaluation of ET tube Colonization Evaluated 10 healthy men (mean age 35) intubated for trauma 9/10 colonized within 12h with rapid increase in numbers of bacteria over 24h and peak at 96h Organisms in lung come from oropharynx and gut Feldman- Eur Resp J 1999;13:

13 Molecular Characterization of Oral Flora Obtained tongue swabs from trauma victims right before bronchoscopy performed Compared cultures of tongue swabs and BAL Compared molecular characterization of bacteria in mouth and in BAL Bahrani-Mougeot FK JClin Micro 2007; 45:

14 16S rrna gene Differs between bacteria Identical in all bacteria PCR to obtain the 16S rrna gene from all bacteria in a sample 16S F 16S R

15 Findings from Tongues 88% of bacteria found on tongue swabs identified using molecular tools --also present in BAL Data suggests oral secretions source of bacteria in lungs 56% bacteria found with molecular tools not found by microbiology lab Bahrani-Mougeot FK JClin Micro2007; 45:

16 Teeth and Plaque 25% of nursing home patients(nhp) have respiratory pathogens in their dental plaques 11/49 NHP had dentures and were significantly less colonized (27% vs 66%) Dental plaque cultures obtained prior to development of VAP documented the same bacteria (PFGE) in plaque that then appeared in VAP cultures El-Solh Chest 2004:126:

17 Bacteria in Mouthwash Report of administration of alcohol-free mouthwash that was contaminated with Burkholderia cenocepacia Ventilated patients died of respiratory infections with this bacteria; others had respiratory illness with this bacteria Documents aspiration of oral flora and importance of oral flora Consider using alcohol-containing mouthwash, esp. chlorhexidine Kutty Chest 2007; epub ahead of print

18 Conclusions RE: Colonization Oropharyngeal colonization, which may be due to dental plaque and/or placement of ET (or NG) tubes, appears to be the major source of bacteria for bacterial-induced VAP Bacteria form biofilms on tubes within hours of placement How do we know when patients are just colonized or when they have become infected?? Gorman Eur J Clin Microbiol Infect Dis 1993;12:9-17

19 Diagnosis

20 Diagnosis of VAP 48 Hours of Hospitalization- Patients develop 2 of 3 of the following: Fever > 38.5 o C or hypothermia; Leukocytosis >10,000 or leukopenia <4000 Purulent secretions and new and persistent/progressive infiltrate on chest radiograph (except ARDS)

21 Diagnosis of VAP Criteria have high sensitivity but very low specificity Will overtreat if use only these criteria-- only 50% of patients diagnosed with VAP using the clinical criteria have lung infections How to confirm the dx? Lisboa Curr Op Infect Dis 2008;21:

22 Postmortem vs clinical dx VAP 25 patients had autopsy evidence of VAP CXR-13/25 had localized infiltrates;7 had diffuse;5 had no chest radiograph findings WBC-15/25 had increased-- 10 did not Purulent secretions-16/25 had some- 9 did not Fabregas N Thorax 1999;54:

23 How to tell if there is VAP?? CRP and Procalcitonin-- no adequate cut-off for definitive dx CRP does go down with adequate antibiotic tx Combining biomarkers with clinical signs may be valuable Lisboa Curr Op Infect Dis 2008;21:

24 Thresholds for Quantitative Cultures

25 Bacterial Thresholds for Infections Obtained BALs and Protected brush specimens in patients who had just diedsamples within 1 hour of death Did thoracotomies and took lung out that had been sampled Cultured lungs--infected lungs grew 10 4 cfu/gram of lung Chastre J Am Rev Respir Dis 1984;130:924-9

26 Sensitivities/Specificities of Tests Bronchoscopic BAL at 10 4 cfu/ml- 91% sensitive and 78% specific Chastre J Am Rev Respir Dis 1984;130:924-9 Blind Mini-BAL at 10 3 cfu/ml was 78% sensitive and 86% specific --used 20ml and retrieved 2ml Bregeon F.Eur Respir J 2000;16:

27 Comparisons to Bronchoscopic BAL Perform repeated BALs-75% reproducibility Quantitative Cultures of endotracheal aspirates- if use threshold of 10 6 cfu/ml has a sensitivity of 68% and specificity of 84% Jourdain B Am J Respir Crit Care Med 1995;152:241-6

28 Threshold in VAP in Trauma Patients Performed fiberoptic bronchoscopy and BAL- 100 ml on 526 patients Stopped antibiotics if BAL cultures were less than 10 5 cfu/ml Followed patients, if became febrile again then had another BAL--if then had a culture with 10 5 cfu/ml first BAL called a falsenegative study Croce MA J Trauma 2004;56:

29 Outcomes of Trauma Patients Highest mortality in patients with 10 5 cfu/ml-- 17% vs 15% for 10 4 cfu/ml and 13% for 10 3 cfu/ml or less; not statistically different 43/1372 BALs considered false negative as next BAL[within 7 days] over threshold;36 had 10 4 cfu/ml and 8 had fewer than 1000 cfu/ml They suggest they accept 10 4 cfu/ml for Pseudomonas and Acinteobacter Croce MA J Trauma 2004;56:

30 Chronic Ventilator Patients 14 patients in chronic ventilator facility; all have tracheostomies and had been on for > 5 months All 14 had > 10 4 cfu/ml in distal airways without fever, white count or chest radiograph findings After tracheostomies and on chronic ventilation see high bacterial burdens constantly Baram D Chest 2005;127:

31 Use Test Data Heyland compared invasive, quantitative cultures of BAL to noninvasive, nonquantitative culture of tracheal aspirate No differences in antibiotic administration or outcomes --excluded MRSA and P.aeruginosa No de-escalation of antibiotics even when cultures were negative! Did not use data from tests Canadian Critical Care Trials Group N Engl J Med 2006;355:

32 Conclusions on Thresholds Quantitative Cultures may allow you to discontinue antibiotics--and may help decrease antibiotic resistance Maybe able to use higher thresholds in trauma patients Appears safe to with-hold antibiotics if patient not have large quantity of bacteria, if patient is getting better and lack of ongoing data that patient has lung infection

33 Prevention

34 DECREASE SEDATION Documentation that daily interruption of infusions of analgesics and sedatives led to: Significant reduction of mechanical ventilation Shorter ICU length of stay Fewer diagnostic tests for mental status --With less posttraumatic stress disorder (PTSD) Kress JP Am J Respir Crit Care Med. 2003:168: ; Schwickert WD Crit Care Med 2004;32:

35 Development of VAP Day 5 Day 10 Day 15 Day 20 Rello, CCM 2003.

36 Prone Position? Meta-analysis of prone position trials Found a non-significant trend to decrease VAP [23% reduction in the odds for VAP] Could be due to decreased aspiration of secretions Abroug Intensive Care Med 2008 Epub ahead of print March 19

37 Tracheostomy Advantages of tracheostomy- Decreases airway resistance Fewer oral-labial ulcerations Better oral hygiene Improves airway security Better patient comfort Maybe fewer pulmonary infections Combes A Crit Care Med 2007;35:802-7

38 Tracheostomies in France Retrospectively analyzed 1629 consecutive patients ventilated for more than 3 daysfound 506 patients 166 tracheostomized after a median ventilation of 12 days Increased mortality in patients without trachs- -48% vs 37% in hospital mortality [p=.03] Matched case-control-trach patients again lower in hospital mortality[36% vs 50%] Combes A Crit Care Med 2007;35:802-7

39 More on Tracheostomies Kollef studied 521 patients ventilated for > 12h and the 51 patients with trachs had lower ICU and hospital mortality rates Rumbak- prospective, randomized trial of 120 patients where patients had trach within 48h;the patients with early trachs had 32% mortality with 62%mortality with later trach Rumbak MJ Crit Care Med 2004;32: Kollef MH Crit Care Med 1999;27:

40 Why Trach? Less sedation--so probably less aspiration of both oral and GI flora Endotracheal Tube in mouth leads to more changes in oral flora with probably more pathogenic flora colonizing mouth and being aspirated Safer when moving patient--patient gets out of bed more

41 Chlorhexidine Koeman et al: Decreased VAP if use Chlorhexidine in gel on teeth and gums Segers et al: Decreased VAP if use chlorhexidine rinses 4 times a day and put into nares Chlorhexidine has been shown to be a superior antiseptic rinse in periodontal literature Segers P JAMA 2006;296: Koeman M Am J Respir Crit Care 2006;173:

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43 Subglottic Suction Devices New device coming from the makers of LMA-- in anesthetized patients, 5% vs 67% VAP with standard cuffs Studies with CAS System have shown an absolute decrease of VAP by 5% and prolongs the time to VAP Young PJ Crit Care Med 2006;34: Valles J Ann Intern Med 1995;122:179-86

44 Surveillance Cultures W/in 12 h of admission, blinded minibal ; 20-30mL sterile saline Repeated every 48 h and then 3 times a week; not done on >70% Fi02 Did gram stains and % of intracellular organisms Daily screening with CPIS Boots Respirology 2008;13: 87-96

45 Surveillance Cultures cont Surveillance cultures predicted up to 90% of the organisms causing VAP Concordance of 90% if specimen within 48 h of VAP Did not find quantification of cultures helpful Found high and stable concentrations of MRSA and P.aeruginosa-- no change with antibiotic therapy Boots Respirology 2008;13: 87-96

46 Conclusions RE: Prevention Consider tracheostomies by 14 days- If new study results compelling, more trachs Consider chlorhexidine- downside is possible discoloration of teeth that can be cured with polishing teeth Consider subglottic suctioning systems

47 Predictions for Future Antibiotics should be given only to patients who are infected Infections will be diagnosed quickly using molecular techniques to identify patients with a high burden of bacteria and signs of infection using objective data, which will include biomarkers

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