VAP prevention – non-antimicrobial methods

Monday 6 th September 2010
London
VAP prevention – non-antimicrobial methods
Dr Duncan Wyncoll, Guy’s & St Thomas’ NHS
Foundation Trust, London, UK
Conflicts of Interest
In the last 5 years I have acted as consultant,
or received honoraria/research grants from:
Abbott, AstraZeneca, Aqix, Bard, Bioproducts,
ConvaTec, Cook, Covidien, Eli Lilly, Fresenius, GSK, Iskus
Health, Kimberly-Clark, Pfizer, Sage, Takeda, Venner &
Zassi

ICU acquired infections are common
SOAP study. Crit Care Med 2006; 34: 344-53

1970 –
1980’s
VAP is an iatrogenic ‘syndrome’

Almost Universal Failure with HVLP Cuffs
Photograph courtesy of Dr Peter Young

Pepsin – in the lungs!
• Intra-tracheal pepsin used as marker for gastric
aspiration in critically ill intubated patients
• >6,000 tracheal aspirates (360 patients)
• 89% of patients had pepsin detected at some
stage
• Aspiration was the most significant independent
risk factor for pneumonia
9/10 patients aspirate stomach contents
Methany NA et al, Crit Care Med 2006; 34: 1007-15

PREVENTION STRATEGIES FOR VAP
Hand hygiene
Avoid unnecessary antibiotics
Shorten antibiotic courses
Avoid ulcer prophylaxis
Use sucralfate if required
Closed circuit suctioning
Chlorhexidine oral rinse
Consider SDD
Consider NIV
Shorten duration of MV
Semi-recumbent position
Avoid circuit manipulation
Avoid patient transportation
Reduce accidental extubation
Subglottic suctioning
Optimize cuff design/pressure
Coating the catheter
PATHOGENESIS OF VAP
Bacterial Colonisation
(oropharynx, stomach, sinuses)
Aspiration of Contaminated
Secretions
(& ventilator circuit condensate/aerosol)
VAP
The relationship between pathogenesis and prevention strategies for VAP
Modified from Kollef M, Crit Care Med 2004; 32: 1396-1405

Supine body position as a risk factor for nosocomial
pneumonia in ventilated patients: a randomized trial.
Drakulovic MB et al, Lancet 1999; 354: 1851-8
%
P=0.003
P=0.018
• n=86
• Semi-recumbent vs.
supine
• Supine body position &
enteral nutrition were
independent risk factors
for pneumonia

Feasibility and effects of the semirecumbent position to
prevent VAP: a randomized study.
van Nieuwenhoven CA et al, Crit Care Med 2006; 34: 396-402
• Prospective multicentre
trial of 221 patients
• 45 o vs. 10 o
NS
NS
• Target of 45 o not achieved
85% of the time
• On average achieved 28 o
vs. 10 o

Benefits seen in ‘Drakulovic’ trial were not sustained…
%
Valencia M et al, Crit Care Med 2007; 35: 1543-9

Efficacy & safety of a paired sedation & ventilator weaning
protocol for mechanically ventilated patients in ICU
(Awakening & Breathing Controlled trial).
Girard TD et al, Lancet 2008; 371: 126-34
• 4 centres, 336 ventilated patients – ‘daily awakening & SBT’
Intervention
N=168
Control
N=168
P Value
Days w’out breathing assistance 14.7 11.6 0.02
ICU LOS 9.1 12.9 0.01
Hosp LOS 14.9 19.2 0.04
Self extubation 16 6 0.031
Reintubation after self-extub 5 3 NS
• Interruption of sedatives & daily SBT reduces time on MV
No reported effect on VAP, but if the patient isn’t intubated…

Oropharyngeal cleansing with 0.2% chlorhexidine for
prevention of pneumonia in critically ill patients: a
randomized trial.
Panchabhai TS et al, Chest 2009; 135: 1150-6
• CHX 0.2% vs. 0.1% potassium permanganate applied BD in
471 patients
0.2% CHX
N=224
Control
N=247
P Value
VAP incidence 16 (7.1%) 19 (7.7%) NS
Day of development of
pneumonia (median)
5 5 NS
• No difference in any other outcome measured
What about higher concentrations used more frequently…

Randomized controlled trial & meta-analysis of oral
decontamination with 2% CHX for the prevention of VAP.
Tantipong H et al, Infect Control Hosp Epidemiol 2008; 29: 131-6
• CHX 2% applied QDS to teeth whilst intubated
2% CHG
N=102
Control
N=105
P Value
VAP incidence 5 12 0.08
VAP/1000 vent days 7 21 0.04
Irritation of oral mucosa 9.8% 0.9% 0.001
• Combined results with other similar study
• Relative risk for VAP 0.53 (0.31-0.9; p=0.02)
Cheap intervention, 90% tolerance & its widely practiced…

Draft High Impact Intervention No 5 – 2010
(Care bundle to reduce ventilation-associated pneumonia)
3. Oral Hygiene
• The mouth is cleaned with chlorhexidine
gluconate (≥1-2% gel or liquid) 6 hourly
• Teeth are brushed 12 hourly with standard
toothpaste

Cuff Shape/Material & VAP
Coefficient of variation of
cuff pressure
PVC
n=26
CPU
n=22
TPU
n=28
P value
82 ± 48 92 ± 47 135 ± 67 0.002
Pepsin level, ng/ml 408 ± 282 217 ± 159 178 ± 126

Silver-coated ET tubes & VAP

Silver-coated ET tubes & VAP
Kollef MH et al, JAMA 2008; 300: 805-13

Silver-coated ET tubes & VAP
VAP @ anytime
- Intubated ≥ 24 hrs
VAP @ anytime
- All Intubated
VAP within 10 days
of intubation
- Intubated ≥ 24 hrs
Silver tube
Uncoated
tube
RRR %
P value
4.8% 7.5% 36 0.03
3.8% 5.8% 34 0.04
3.5% 6.7% 48 0.005
VAP within 10 days
of intubation
- All Intubated
2.8% 5.2% 46 0.007
Kollef MH et al, JAMA 2008; 300: 805-13

Silver-coated ET tubes & VAP
(Microbiology)
Silver tube
Uncoated tube
Staphylococcus Aureus 9 16
MRSA 3 7
Pseudomonas Aeruginosa 8 11
Enterobacteriaceae 10 5
Yeasts 5 7
Streptococcus species 4 7
Haemophilus Influenza 3 3
Acinetobacter Baumannii 1 5
Other 5 17
Kollef MH et al, JAMA 2008; 300: 805-13

Pneumonia in intubated patients: role of respiratory
airway care.
Rello J et al, Am J Respir Crit Care Med 1996; 154: 111-5
• 83 consecutive intubated patients undergoing continuous
aspiration of subglottic secretions (CASS)
• Failure of CASS (RR = 7.5, 95% CI = 1.5-38) & persistent
intracuff pressure below 20 cm H 2 O (RR = 4.2, CI = 1.1-16)
were factors independently associated with VAP
• Colonized subglottic secretions around the cuff are the
most important risk factor for VAP in the 1 st 8 days of
intubation
• Study confirmed the importance of maintaining adequate
cuff pressure & effective subglottic aspiration to prevent
pneumonia

Automatic control of tracheal tube cuff pressure in
ventilated patients in semirecumbent position.
Valencia M et al, Crit Care Med 2007; 35: 1543-9

Subglottic Secretion Drainage Tubes

National Recommendations
Year
30 o Bed
elevation
Subglottic
secretion
drainage
NICE (UK) 2008 Yes No Yes
Brit Soc Antimicrob Chemotherapy 2008 Yes Yes No
Scottish ICS 2008 Yes Yes Yes
European HAP working group 2008 Yes Yes Yes
Canadian Clinical Trials Group 2008 Yes Yes Yes
Canadian Critical Care Society 2008 Yes Yes No
American Assoc for Resp Care 2008 Yes Yes No
IHI (US) 2006 Yes Yes No
American Thoracic Society 2005 Yes Yes No
American Assoc of Crit Care Nurses 2004 Yes Yes No
CDC (US) 2003 Yes Yes No
Oral
CHX

Subglottic Secretion Drainage & VAP
Study n SSD (%VAP) Control (%VAP) p
Mahul 1992 145 13 29 p

Subglottic Secretion Drainage Tubes
• Are slightly stiffer & the cuffs are still not 100%
effective
• 48% failure rate – due to prolapse of mucosa into
the suction port [Dragoumanis et al, 2007]
• Design is improving rapidly; now 3 rd generation
• Highly cost-effective
• They don’t yet ‘eliminate’ VAP, but may be the
most effective single non-antimicrobial
intervention

Kimberly-Clark
£~15 ~£6
~£10
Covidien
Taperguard
Teleflex
~£10
Portex SACETT
~£5
Malinckrodt
~£140
~$90
Bard Argento
Young Lotrac

Nosocomial pneumonia risk & stress ulcer prophylaxis: a
comparison of pantoprazole vs. ranitidine in
cardiothoracic surgery patients.
Miano TA et al, Chest 2009; 136: 440-7
• SUP is associated with ↑ risk of VAP
• PPIs are linked to ↑ risk of CAP
• Retrospective review of 824 patients receiving SUP
PPI
N=377
H 2 RA
N=457
Nosocomial pneumonia 9.3% 1.5% 6.6 (2.9-14.9)
OR
• Multivariate logistic regression – pantoprazole was only
factor +ve for pneumonia: OR 2.7 (1.1-6.7)
SUP unlikely to have major effect on VAP, but some effect…

Stress ulcer prophylaxis & VAP
VAP/CDT
Bleeding
Limit prophylaxis to high-risk patients: e.g.
• Acute kidney injury/acute hepatic failure
• Patients with INR >1.5, or platelets

Early vs. late tracheostomy to prevent VAP
‣ Day 6-8 vs. Day
13-15
‣ [i.e. UK practice
vs. US]
Terragni PP et al, JAMA 2010; 303: 1483-7

The UK TracMan trial
N=909 Early (Day1-4) Late (>10 days)
30d mortality 30.8% 31.5%
ICU LOS 13 13
Hosp LOS 33 34
Antibiotic use
• Identical
Sedation
• Lower in early arm
• Mean 6.9 vs. 9.3 days
54% of ‘late’ arm (wait & see arm) never needed a
tracheostomy!

Timing of VAP onset
Number of patients with VAP
Average timing of
tracheostomy in UK
‣ 6-month
study
‣ 175 patients
‣ VAP in 56
Apostolopoulou E et al, Respir Care 2003; 48: 681-8

Tight glucose control to prevent VAP
Conventional ~ 8 mmol/L
Intensive ~ 5.5 mmol/L
NICE-SUGAR Investigators. NEJM 2009; 360: 1283-97

Tight glucose control to prevent VAP
NICE-SUGAR Investigators. NEJM 2009; 360: 1283-97

Tight glucose control to prevent VAP
NICE-SUGAR Investigators. NEJM 2009; 360: 1283-97

Selective Decontamination to prevent VAP
De Smet A et al, NEJM 2009; 360: 20-31

Selective Decontamination to prevent VAP
De Smet A et al, NEJM 2009; 360: 20-31

Reducing VAP – non-antimicrobial interventions
Semirecumbency
has limited effect
Cuff pressure &
shape is important
Microaspiration
is common
CHG 2% seems to ↓VAP
Subglottic
secretion drainage
is reliably effective
Early
tracheostomy
may ↓VAP, but
not before day 7
Stress ulcer
prophylaxis has
uncertain effect
on VAP
But
is best
reserved for
high-risk pts
Application of
common sense
& technology