Ventilator Associated Pneumonia

Dr Hazilawati Hussin

Microbiologist

Hospital Wanita & Kanak-kanak Kuala Lumpur

Outline

• Definition

• Pathogenesis

• Risk factor

• Control and Prevention

Ventilator-associated pneumonia (VAP)

• Pneumonia that develops within 48 hours

of initiation of mechanical ventilation and

which was not developing at the time of

initiation of mechanical ventilation VAP

HAP

• Patients on mechanical ventilation have 6–20X the risk for hospital-acquired pneumonia compared with patients not on ventilatory support

Epidemiology

• Incidence of VAP: 10% to 25%

• Criteria of diagnosis varies from study to study and

difference in standards and practice

• Rates for VAP : per 1,000 ventilator days

• Cumulative incidence of 1 – 3% per ventilator days

Chastre J, Fagon JY. Ventilator-associated pneumonia. Am J Respir Crit Care Med 2002; 165: 867–903.

Implications

VAP increases :

Ventilator days

ICU ( ~ 7d) and hospital LOS

Mortality rates

- 46% (ventilated with VAP) vs 32% (ventilated without VAP)

- 2- to 10-fold higher risk of mortality

- Crude ICU mortality rates is 24 – 76%

Medical costs-additional $10,000 per case

Ibrahim Chest 2001

Chastre . Am J Respir Crit Care Med 2002Rello Chest 2002, Worrall et al J Trauma Injury Infect Crit Care 2010

VAP: Source of infection

ENVIRONMENT

STAFF

PATIENT

(endogenous)

EQUIPMENT

OTHER

PATIENTS

bacteria colonising the oropharynx or GIT

Pathogenesis

Colonisation of the aerodigestive tract

with pathogenic bacteria

• Primary route of bacterial entry into

lower respiratory tract is either from

micro or macro aspiration of

oropharyngeal pathogens

-Aspiration of contaminated

secretions/fluids (eg ventilator

tubing condensate) into the lower airway

-Leakage of secretions containing

bacteria around the ETT cuff

Causative organisms

• Early-onset (< 4 days)

- S.pneumoniae

- H. influenzae

- MSSA

- Antibiotic-sensitive

enteric GNB

- E.coli

- K.pneumoniae

- Enterobacter spp

- Proteus spp

- Serratia marcerans

• Late-onset (>4 days)

plus MDR pathogens

- P.aeruginosa

- K.pneumoniae (ESBL)

- Acinetobacter spp

- MRSA

RISK FACTORS

CLINICAL

Clinical suspicion of VAP

• Presence of >2 of the following 4 criteria

fever >38.5°C or < 36°C within last 24 hr

TWBC > 12,000/mm3within last 24 hr

purulent tracheobronchial secretions within last 24 hr

reduction of PaO2/FiO2>15% in the last 48 hrs

Microbiological-Bad bugs:Pathogen in VAP

Early–Onset Pneumonia (< 4 days of intubation or ICU admission)

• Community-acquired

• Pathogens:

-Streptococcus pneumoniae

-Haemophilus influenzae

-Staphylococcus aureus

• Antibiotic-sensitive

- Enteric GNR

Late-Onset Pneumonia(> 4 days of intubation or ICU admission)

• Hospital-acquired • Pathogens:

• Pseudomonas aeruginosa

• (MRSA)

• Acinetobacter

• Enterobacter

• Antibiotic-resistant ; MRO,ESBL

Microbiological Dx: suitable specimen

Non-bronchoscopictechniques

Tracheal aspiration

Percutaneous needle aspiration

Blind bronchial sampling (“Blind” BAL)

Bronchoscopic techniques

• Protected specimen brush (PSB)

• Bronchoalveolar lavage(BAL)

Microbiological diagnosis

• Tracheal colonisation is common in intubated patients

• In absence of clinical findings of infection, does not require therapy or diagnostic evaluation

• Samples of lower respiratory tract secretions should be obtained from all patients with suspected VAP prior to antibiotic changes

• Choice of diagnostic test depends on local expertise, experience, availability, and cost

CONTROL AND PREVENTION OF VAP

Interventions for VAP prevention:

Colonisation of the aerodigestive tract

Aspiration

Contaminated equipment

designed to interrupt the 3 most common

mechanisms by which VAP develops:

General strategies

• Conduct active surveillance for VAP

• Adhere to hand-hygiene guidelines published by the CDC and WHO

• Use non-invasive ventilation whenever possible-to consider Non invasive positive pressure ventilation

• Minimize the duration of ventilation

• Perform daily assessments of readiness to wean and use weaning protocols

• Educate HCW who care for patients undergoing ventilation about VAP

Staffing ratio

• influence the length of stay

• inverse relationship between the adequacy of staffing levels and duration of stay and subsequent development of HAP/VAP

• Prevention of cross infection

Strategies: Prevent aero digestive tract colonisation

• Avoid unnecessary antibiotic administration

• Short-course antibiotics

• Avoid unnecessary stress ulcer prophylaxis

• Oral intubation

• Chlorhexidine oral rinse

• Hand hygiene

Strategies: Prevent aspiration

• Use non invasive ventilation whenever possible

• Semi recumbent positioning (head elevation 30-45 degrees)

• Avoid unnecessary manipulation/changes of the ventilator circuit. Don’t routinely change ventilator circuits unless soiled

• Drain ventilator circuit condensate

• Avoid patient transports

• Prevent accidental extubation

• Avoid gastric over distension

• Subglottic suctioning

Strategies: Minimize contamination of equipment

• Use sterile water to rinse reusable respiratory equipment

• Remove condensate from ventilator circuits. Keep the ventilator circuit closed during condensate removal

• Change the ventilator circuit only when visibly soiled or malfunctioning

• Store and disinfect respiratory therapy equipment properly

VENTILATOR CARE BUNDLE

Care Bundles

What is a Care Bundle?

A set of individual components which when combinedmake a set of quality indicators for a specific system, procedure or treatment

E.g: Ventilator care bundle

Central venous line bundle

Sepsis bundle

Definition of a Bundle

A collection of things or quantity of material tied or wrapped up together

Concise Oxford English Dictionary

Ventilator care bundle

• Head of bed elevation 30-45˚

• Sedation vacation

• Peptic ulcer disease prophylaxis or treatment

• Deep vein thrombosis prophylaxis (heparin) and treatment

Sedation vacation

• Patients with daily interruption of sedative infusions appear to have a lower complications related to prolonged mechanical ventilation

eg VAP, bacteraemia, barotrauma, venous thromboembolism, cholestasis and sinusitis

THANK YOU