Question 25

Your intensive care unit has had a noticeable increase in the rate of ventilator - associated pneumonia (VAP). A number of cases involve multi - resistant organisms.

Outline the strategies you would recommend implementing in your unit in an effort to reduce the incidence of VAP.

Explain the rationale for each recommended quality improvement strategy in your answer.

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College Answer

Infection control procedures

Review routine infection control procedures e.g. hand washing, personal protection (gloving, gowning etc.), isolation policies for MDR organisms and airborne pathogens.

Benefits include a reduction in transmission of organisms from patient to staff and staff to patients hence reducing colonisation. Generally evidence of benefit exists for many of these strategies (e.g. hand washing) and there is also evidence of poor or less than perfect compliance.

Robust infection control governance and systems are also mandatory under new National Standards for Safety and Quality in Healthcare (Standard 3) including the need for regular audit and feedback.

Direct patient care strategies to prevent VAP

The presence of an endotracheal tube, micro aspiration and poor clearance of respiratory secretions is thought to the key to pathogenesis of VAP. Therefore the implementation of a so- called ‘VAP bundle’ or similar is worth considering (although not all elements have a high level of evidence).

Strategies include:

  • Remove tube at earliest possible time
  • Elevate head of bed >30 degrees
  • Daily mouth care (meticulous dental care and/or Chlorhexidine mouthwash)
  • Minimise circuit manipulation
  • Appropriate cuff pressures

May also consider:

  • ETTs with subglottic suctioning
  • Selective digestive decontamination
  • Limiting the use of PPIs
  • Weaning and sedation protocols

Antibiotic stewardship

Implement antibiotic stewardship including review of current prescribing practice, consideration of regular infectious diseases input, ICU and hospital specific antibiogram to guide antibiotic use and possible regulation of prescription of certain antibiotic classes.

No high level evidence of benefit for individual patients but generally considered to be important to avoid overuse of broad spectrum antibiotics in particular and limit the development of MDR pathogens. Good antibiotic stewardship may also increase the adequacy of empiric antibiotic cover, which is associated with improved mortality.

Environmental cleaning and decontamination

Review of cleaning procedures and compliance with Australian regulations regarding the surrounding environment is warranted.

For example:

  • Staphylococcus remains viable on dry surfaces and be transmitted to staff and patients hence the entire bedspace including high surfaces must be cleaned regularly.
  • Aspergillus may be transmitted via airborne spread of spores particularly to immunosuppressed patients in the setting of construction or renovation.
  • Serratia has been linked to spread via sinks particularly if non-compliant with current design regulations.

Ongoing measurement and audit program

Ongoing measurement and feedback of clinically relevant processes and outcomes is a key to any quality improvement strategy and essential to demonstrate future improvement.

Problems exist with definitions for VAP including poor reliability and gaming of results. Even so review of existing data and data quality with appropriate statistical measures is important to be able to distinguish common cause from special cause variation.

It should not necessarily be assumed that the current increase in cases is based on reliable data or that it is statistically significant.

Equally important is allocation an appropriate clinician (nurse or doctor) with the responsibility and time to champion the cause and provide regular feedback to other staff.

This would likely be included in a wider quality and safety or infection control portfolio.

Additional comments:
Candidates were expected to give a clear statement of each strategy with a mature explanation
of the rationale, not just state, for example, “VAP bundle”

Discussion

Below, a table is reproduced from the ventilator-associated pneumonia (VAP) chapter in the required reading section of the site. It concerns the organisation-level strategies to reduce the risk of VAP. In addition to this, there are direct bedisde strategies, which are as follows:

Strongly evidence-based advice

  • Early extubation, avoidance of intubation
  • Avoidance of reintubation
  • Avoid NG tubes
  • Use of higher cuff pressures (~ 20cmH2O)
  • Use of above-the-cuff subglottic suction
  • Minimised sedation and paralysis
  • Sit them up to 45° (avoid being supine)

Advice based on weak evidence

  • Consider using post-pyloric feeds
  • Consider selective digestive decontamination
  • Reduce the use of stress ulcer propylaxis.
Organisation-Level Strategies for the Prevention of VAP
Strategies Specific interventions Rationale and literature support
Education
  • Distribution of materials
  • Meetings
  • Outreach visits

According to the abovequoted review (Crnich et al, 2005) this has a  modest and shortlived effect on the process of care. Furthermore, most survey respondents (in a 2004 systematic review) felt that they were only sufficiently resourced to disseminated printed material and to hold informal lunchtime meetings.

Infection control procedures
  • Hand-washing
  • PPE
  • Isolation policies for resistant organisms

The literature in support of this is Standard 3, ACSQHC: this stuff is actually as mandatory as your compulsory annual fire training. The rationale for it is that scupulous attention to infection control might prevent VAP by preventing the transmission of multi-resistant organisms.

Does it help with VAP? Probably,. At least one study (Koff et al, 2011) has found an improvement in VAP after the introduction of a comprehensive hand hygiene program.

Antibiotic stewardship
  • Regulated antibiotic prescribing
  • Mandatory ID input
  • Review of prescribing practice

The college hastens to add that there "is no high level evidence" to demonstrate that antibiotic stewardship has very much effect on the rates of VAP. In fact some reasonable quality studies do exist (Gruson et al, 2000). The authors were able to decrease both their VAP rates and the incidence of multi-resistant bacteria by starting a program of antibiotic supervision and regular rotation. However, this was a French hospital where the random wanton use of ceftazidime and ciprofloxacin was rampant prior to the study protocol.

Environmental
decontamination

  •  Compliance with the (already strict) practice protocols
  • Air filtration
  • Hygiene of the ventilator circuit
  • Decontamination of potable tap water
  • Single-use airway devices

This does not refer exclusively to the "terminal cleanining" of a bed space, and is inclusive of the ventilator tubing, the bed itself, the bedside sink, the room air conditioner filter, etc etc. But the bed space is probably the most important: for example, This Irish infection control protocol (2011) cites a brilliant review from Respiratory Care (Crnich et al, 2005). Crnich et al produce a massive table of environmental factors which influence the risk of VAP, including contaminated respiratory equipment, poor ambient air filtration, dislogement of Aspergillus spores during construction activities, and so forth. The review quotes evidence for the importance of these factors among its 388 references.

Audit of activities
  • Reliable definition of VAP, consistent over the course of audit
  • Data collection protocol
  • Scheduled reviews
  • Allocation of auditor responsiilities

Is there a point to this? To many it seems like pointless busywork. Indeed, a widely cited 2004 meta-analysis (Grimshaw et al, 2004) found that "the effect of audit and feedback on improving professional practice was small to moderate", and that "variability in the study quality and reporting transparency makes it difficult to recommend widespreaduse of audit and feedback". This was not specific to infection control, but pertaining to the broader tendency of healthcare staff to spontaneously self-organise into committees and auditing bodies.

References

Koff, Matthew D., et al. "Reduction in ventilator associated pneumonia in a mixed intensive care unit after initiation of a novel hand hygiene program." Journal of critical care 26.5 (2011): 489-495.

Gruson, Didier, et al. "Rotation and restricted use of antibiotics in a medical intensive care unit: impact on the incidence of ventilator-associated pneumonia caused by antibiotic-resistant gram-negative bacteria." American journal of respiratory and critical care medicine 162.3 (2000): 837-843.

Crnich, Christopher J., Nasia Safdar, and Dennis G. Maki. "The role of the intensive care unit environment in the pathogenesis and prevention of ventilator-associated pneumonia." Respiratory Care 50.6 (2005): 813-838.

Sinuff, Tasnim, et al. "Ventilator-associated pneumonia: improving outcomes through guideline implementation." Journal of critical care 23.1 (2008): 118-125.

Grimshaw, J. M., et al. "Effectiveness and efficiency of guideline dissemination and implementation strategies." International Journal of Technology Assessment in Health Care 21.01 (2005): 149-149.