Transcript Ventilator Associated Pneumonia and SDD

Ventilator Associated Pneumonia
Dr. Hany V. Zaki
Lecturer of Anaesthesia and ICU Department
Ain Shams University
Introduction

Most
patients
who
receive
mechanical
Ventilatory support for a protracted period
develop microbial colonisation of the airway

A subset of these patients develops invasive
infection requiring antibiotics

VAP is the commonest ICU acquired infection
Definition

Pulmonary infection acquired in hospital, at least 48
hours after intubation and ventilation.

Traditional clinical features (pyrexia, leucocytosis,
pulmonary infiltrates on CXR, positive endobronchial
sputum culture) may be inadequate.
Incidence and Risk Factors

Incidence:

In
2002,
an
estimated
250,000
healthcare-associated
pneumonias developed in U.S. hospitals and 36,000 of these
were associated with deaths.

For the year 2010, NHSN facilities reported more than 3,525
VAPs and the incidence for various types of hospital units
ranged from 0.0-5.8 per 1,000 ventilator days
(Dudeck MA, Horan TC, et. al. National Healthcare Safety Network (NHSN) Report, Data
Summary for 2010)
Mortality
Mortality ranges from 20 to 41%,
depending on infecting organism,
antecedent antimicrobial therapy, and
underlying disease(s)
COST OF VAP

Strikingly, VAP adds an estimated cost of
$40,000 to a typical hospital admission

Risk Factors:

Duration of ventilation. 3% per day in first week, 2% per
day in second, 1% per day after

Severity of illness: high APACHE II scores (>16)
correlate with risk of VAP

Head injury or other cause of coma

Burns and trauma

Acute of chronic respiratory condition, ARDS

Male sex and increasing age
Early vs Late

Early onset pneumonia occurs during the first four
days of hospitalization and is often caused by Moraxella
catarrhalis, H. influenzae, and S. pneumoniae.

Late onset pneumonia are frequently gram negative
bacilli or S. aureus, including methicillin-resistant S.
aureus. Viruses (e.g., Influenza A and B or Respiratory
Syncytial Virus), yeasts, fungi, legionellae, and
Pneumocystis carinii.
VAP Etiology


Most are bacterial pathogens, with Gram
negative bacilli common
Pseudomonas aeruginosa





Proteus
Acinetobacter
Staphylococcus aureus
Early VAP associated with non-multi-antibioticresistant organisms
Late VAP associated with antibiotic-resistant
organism
VAP Prevention
General measures
- Universal Precautions and Hygiene
- Feeding
Kinetic therapy
- Stress ulcer and DVT prophylaxis
- Team Approach
Prevention of Aspiration
- Head up
- Cuff pressure of ETT
- Avoid circuit manipulation
- Drainage of secretions
Preventive
measures
for VAP
Decontamination
- Oral decontamination
- GI decontamination
- Silver ETT
Early Extubation
- Early weaning protocol
- Daily sedation brakes
Prevention of VAP
General measures
Prevention of Aspiration
- Universal Precautions and Hygiene
- Head up
- Feeding
- Cuff pressure of ETT
- Kinetic therapy
- Avoid circuit manipulation
-Stress ulcer prophylaxis
- Drainage of secretions
- Team Approach
Preventive
measures for
VAP
Decontamination
- Oral decontamination
- GI decontamination
- Silver ETT
Early Extubation
- Early weaning protocol
- Daily sedation brakes
Hand washing
Wash hands or use an alcohol-based waterless
antiseptic agent before and after suctioning,
touching ventilator equipment, and/or
coming into contact with respiratory
secretions.
CDC Guideline for Prevention of Healthcare Associated Pneumonias
2004
AACN Practice Alert for VAP, 2007
Entral Feeding and VAP

Enteral feeding may predispose to aspiration of gastric
contents and the subsequent development of VAP.

It has been suggested that placement of a post-pyloric
feeding tube might reduce the risk of aspiration and VAP.

A meta-analysis of seven studies found that post-pyloric
feeding showed a trend toward lower incidence of VAP and
mortality than gastric feeding. however, the differences
were not statistically significant

The timing of initiation of enteral feeding has also been
reported to be associated with the development of
VAP. In a large retrospective multicenter analysis, early
feeding (i.e., within 48 hours of onset of mechanical
ventilation) was found to be associated with an
increased risk of VAP, although ICU and hospital
mortality were decreased in the early feeding group
Probiotics and VAP

Probiotics are commercially available preparations of
live non-pathogenic microorganisms administered to
improve microbial balance resulting in health benefits
for the host.

Administration of probiotics has been advocated as a
means of preventing a variety of infections including
VAP in the ICU.

The potential beneficial effect of probiotics in
prevention of VAP may be in their competition with
VAP-producing microorganisms in the oropharynx and
stomach.

In addition, it has been suggested that the benefits of
probiotics might be explained by their immunomodulatory properties.

Administration of probiotics was also found to be
beneficial in reducing length of stay in the ICU and
colonization of the respiratory tract by Pseudomonas
aeruginosa.
Stress ulcer and VAP


The use of acid-suppressive medications and the
subsequent increase in gastric pH allows
bacterial growth in the stomach, increasing the
risk of colonization in case of aspiration of
gastric contents.
A cohort study of more than 60,000 patients
showed an increased risk of hospital-acquired
pneumonia when acid-suppressive medications
were used
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
However, no definitive recommendation can be
provided about the use of acid-suppressive
medications in relation to VAP in the ICU
setting, and stress-ulcer prophylaxis is still
suggested as part of the bundle treatments for
VAP prevention published by the Institute for
Healthcare Improvement
Herzig SJ, Howell MD, Ngo LH, Marcantonio ER: Acid-suppressive medication
use and the risk for hospital-acquired pneumonia.
JAMA 2009, 301:2120-2128
Kinetic therapy

Immobility of the intubated critically ill patient may
impair mucociliary clearance

Mechanical rotation of patients with 40° turns (kinetic
therapy) may improve pulmonary function more than
the improvement in function achieved via standard care
(i.e., turning patients every 2 hours). Kinetic therapy is
believed to improve movement of secretions and to
avoid the accumulation of mucus in dependent lung
zone
Nakagawa NK, Franchini ML, Driusso P, de Oliveira LR, Saldiva PH, Lorenzi-Filho
G: Mucociliary clearance is impaired in acutely ill patients. Chest 2005, 128:27722777
Team Approach

The prevention of VAP is a multidisciplinary
team approach that should involve all health
care givers from doctors, nurses, assistants,
porters, housekeeping as all should act together
with the same protocol to decrease the incidence
of VAP
Prevention of VAP
General measures
Prevention of Aspiration
- Universal Precautions and Hygiene
- Head up
- Feeding
- Cuff pressure of ETT
- Kinetic therapy
- Avoid circuit manipulation
- Stress ulcer prophylaxis
- Drainage of secretions
- Team Approach
Preventive
measures for
VAP
Decontamination
- Oral decontamination
- GI decontamination
- Silver ETT
Early Extubation
- Early weaning protocol
- Daily sedation brakes
Oral Care




Role of oral care, colonization of the
oropharynx, and VAP unclear – dental plaque
may be involved as a reservoir
Limited research on impact of rigorous oral care
to alter VAP rates
Surveys indicate most nurses use foam swabs
rather than toothbrushes in intubated patients
Oral chlorhexidine washes decrease the
incidence of VAP
CDC Guideline for Prevention of Healthcare Associated Pneumonias
2004
Grap M. Amer J of Critical Care 2003;12:113-119.
Silver ETT

Coating the endotracheal tube with silver is theoretically
attractive because silver has broad-spectrum antimicrobial
activity in vitro, reduces bacterial adhesion to devices in

A silver-coated tube has been developed with silver ions
microdispersed in a proprietary polymer on both the inner
and outer lumen, permitting ion migration to the tube
surface to provide a sustained antimicrobial effect.

The polymer may add to the antimicrobial activity of silver
by blocking bacterial adhesion to the endotracheal tube

However, despite numerous studies of various
such interventions, there is insufficient evidence
upon which to base strong recommendations, and
important safety concerns remain regarding the
use of some devices. Most importantly cost
effectiveness data are lacking for modified ETTs
designed to prevent VAP
Respir Care 2010;55(8):1046 –1055. © 2010
Selective Digestive Decontamination


VAP often have an endogenous source of
infection. Colonisation of the digestive tract and
the oropharynx correlates with development of
VAP
SDD = Selectively eliminating potentially
pathogenic organisms (not normal anaerobic
flora) in the digestive tract and oropharynx with
the aim of decreasing the incidence of VAP and
it’s associated mortality

SDD usually involves:
Topical application of non absorbable agents (such
as polymyxin B, tobramycin and amphotericin B)
that have activity against G negative organisms and
fungi.
 Initial use of broad spectrum IV antibiotics for 3-4
days, such as cefotazime.

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Potential benefits:


Decreased VAP, improved mortality, less time in
ITU
Potential problems:

Increased resistant organisms, cost, side effects.
Prevention of VAP
General measures
Prevention of Aspiration
- Universal Precautions and Hygiene
- Head up
- Feeding
- Cuff pressure of ETT
- Kinetic Therapy
- Avoid circuit manipulation
- Stress ulcer and DVT prophylaxis
- Drainage of secretions
- Team Approach
Preventive
measures for
VAP
Decontamination
- Oral decontamination
- GI decontamination
- Silver ETT
Early Extubation
- Early weaning protocol
- Daily sedation brakes
HOB Elevation
HOB at 30-45º
CDC Guideline for Prevention of Healthcare Associated
Pneumonias 2004 ATS / IDSA Guidelines for VAP 2005
36
Primary Route of Bacterial Entry into
Lower Respiratory Tract

Micro or macro aspiration
of
oropharyngeal pathogens

Leakage of secretions
containing bacteria around
the ET cuff
Cuff pressure and VAP


Cuff pressures of less than 20 cm H2O represent a modifiable
risk factor for VAP. Usually cuff pressure is measured
intermittently with the use of a manometer.
The target cuff pressure level was 25-30 cm H2O
Continuous Removal of Subglottic
Secretions
Use an ET tube with
continuous suction
through a dorsal lumen
above the cuff to prevent
drainage accumulation.
CDC Guideline for Prevention of
Healthcare Associated Pneumonias 2004
ATS / IDSA Guidelines for VAP 2005
Circuit manipulation and VAP

Warm expired air condenses in ventilator tubing.
Microbial growth occurs rapidly in the pooled
condensate. Disconnection of the circuit and
manipulation to drain the tubing can cause the
contaminated condensate to dump directly into
the lungs.



Condensation traps permit drainage without
opening the circuit, preventing both microbial
dump and contamination from the external
environment.
Opening the circuit for other procedures should
be avoided. Accumulation of condensate can
also be reduced by heat-moisture exchanger
(HME).
However, care must be taken not to allow
patient secretions to dry, which can cause
endotrachael and tracheostomy tube blockage
Early extubation

The risk of developing VAP increases with
prolonged intubation, and re-intubation is a
known risk factor

Since the ETT is believed to be involved in the
pathogenesis of VAP, many clinicians avoid
intubation when possible.

The early use of NIV with the aim of avoiding
intubation may be worth considering, particularly in
fragile patients.

Although a reduction in VAP incidence has not been
demonstrated, the early use of CPAP reduced the need
for ICU admission and ventilatory support
Squadrone V, Massaia M, Bruno B: Early CPAP prevents evolution of acute lung
injury in patients with hematologic malignancy. Intensive Care Med 2010, 36:16661674

Reduced administration of sedatives is associated with
shorter ICU stays and fewer days of intubation.
Although no data are currently available to prove that
VAP occurrence is decreased by reduced sedative
administration, daily suspension of sedative drugs has
been suggested as a preventive measure.
Blackwood B, Alderdice F, Burns KE, Cardwell CR, Lavery G, O'Halloran P:
Protocolized versus non-protocolized weaning for reducing the duration of
mechanical ventilation in critically ill adult patients. Cochrane Database Syst Rev
2010, 12:CD006904
Coppadoro A *, Bittner E and Berra L. Novel preventive strategies for
ventilator-associated pneumonia. Critical Care 2012, 16:210

However, only a few have been demonstrated to be effective,
and many others still need evaluation in large randomized clinical
trials before definitive recommendations can be made.

Among others, modifications to the ETT (e.g., subglottic
secretion drainage systems, antimicrobial coating, alternative cuff
shapes and materials), continuous maintenance of proper cuff
inflating pressures, ETT secretion removal, patient positioning in
the lateral horizontal position, kinetic therapy, and
administration of probiotics are measures worthy of
consideration and further study in the ongoing battle to reduce
the rates of VAP.