15.10 VAP Flashcards
a) What is meant by the term ventilator associated pneumonia (VAP)? (3 marks)
Nosocomial lung infection
occurring more than 48 hours
after commencement of ventilation
via endotracheal tube.
There are a range of different scoring
systems to aid diagnosis
that include clinical,
microbiological and radiological factors.
The lack of a universally accepted diagnostic tool for VAP causes problems
when comparing rates between units or evaluating interventions to reduce its
incidence. The CDC (see reference at the end of this question) has produced
an algorithm for diagnosing ventilator associated events for the purposes
of surveillance. After a period of 48 hours of stability or improvement on
ventilation, deterioration in oxygenation qualifies as a ventilator associated
event. Further clinical and microbiological findings are then used to determine
whether this is a ventilator-associated condition, infection-related ventilatorassociated
complication, or possible ventilator-associated pneumonia.
b) List the factors that increase the risk of the development of VAP. (10 marks)
> > Endotracheal tube
(loss of cough reflex,
biofilm development on the inner surface of tube,
pooling of secretions on top of cuff that then gain access
via channels caused by folds in the cuff).
> > Nasogastric tube
(colonisation,
predisposition to sinusitis and,
therefore, a pool of infected secretions
on cuff of tube).
> > Nasal intubation
(predisposition to sinusitis and
therefore a pool of
infected secretions).
> > Positive pressure ventilation
(forces bacteria to distal airways).
> > Long duration of mechanical ventilation.
> > Dysfunctions in immune response
associated with critical illness,
e.g. reduced level of salivary fibronectin,
which normally protects against
oropharyngeal colonisation with
aerobic gram negative bacilli and
Staphylococci.
> > Severe burns.
> > Supine position (risk of gastro-oesophageal reflux).
> > Low GCS/excessive sedation.
> > Enteral feeding
(due to risk of aspiration, but for the purposes of overall
morbidity and mortality, enteral feeding is still preferable overall to no/ parenteral feeding).
c) What measures may reduce the risk of development of VAP? (7 marks)
> > Avoidance of intubation,
reducing the duration of intubation where feasible
> > Minimisation of risk of introduction of
pathogens to breathing circuit:
• Hand hygiene.
• Closed suctioning.
• Limit disconnections in circuit.
> > Modifications to tube design:
• Subglottic suction port.
• Tapered cuff of ultra-thin
polyurethane to avoid channelling.
• Antimicrobial coating to
discourage biofilm development.
> > Ventilator care bundle checked at each shift change:
• Nurse 30–45 degrees head
up to reduce risk of aspiration.
Daily sedation hold reduces overall number of ventilated days, facilitates more rapid wean, may help preserve some cough reflex.
• Histamine 2 receptor blocker
is associated with reduced ICU
complications and length of stay,
therefore reduces number of
ventilated days.
• Thromboprophylaxis –
reduced complications reduces
length of stay and ventilated days.
• Oral hygiene with chlorhexidine mouthwash.
• Cuff pressure check
(20–30 cm H2O or 2 cm
H2O above peak inflation
pressure).
> > Ensuring ventilator tubing
positioned so that the condensate does not
drain into the patient.
Care bundles?
A care bundle is a group of evidence-based interventions that relate to a particular aspect of patient care.
The strength of evidence supporting the
individual components varies;
some elements may just be accepted as good
practice.
Nonetheless, the aim of care bundle
use is that the implementation
of all of the components together
should result in better patient outcomes.
Care bundles are readily auditable.
Think about the care bundles for sepsis
management or reduction of surgical infection
(part of the WHO checklist).
