Putting QIPP into critical care

Following an introduction from Alex Moffat, clinical quality manager at the Norfolk, Suffolk & Cambridgeshire Critical Care Network, the Critical Care Study Day, which is supported by an educational grant from Kimberly - Clark, opened with a presentation from Dr Peter Young, a consultant intensivist from Queen Elizabeth Hospital, King’s Lynn, who spoke about the Department of Health’s latest High Impact Intervention (HII) care bundle to reduce ventilator-associated pneumonia (VAP), which is the most frequent cause of nosocomial infections in the critical care environment.1 Safdar et al,2 found that the incidence of VAP is 10 to 20%, with a two-fold increase in mortality attributable to VAP and the ICU length of stay was increased by a mean of 6.1 days with an attributable cost of $10,019 per case. Muscedere et al3 found that length of stay attributable to VAP increases by 4.3 ICU days, occupying 2% of all ICU days.

Pneumonia is the second most common nosocomial infection in critically ill patients, affecting 27% of all critically ill patients.4 According to Zolfaghan and Wyncoll,5 prevention of VAP is one of the most costeffective interventions currently attainable in the ICU. Dr Young stressed the importance of remembering that it occurs as a consequence of tracheal intubation in critically ill patients. Subsequent bacterial colonisation of the oropharynx and then silent continuous aspiration past the cuff of the tracheal tube with contaminated secretions is the likely pathogenesis. Describing the speed of the VAP pathogenesis pathway, quoting work from Feldman et al, Dr Young said: “Mouths and stomachs become colonised very quickly – within one or two days – when a patient is being mechanically ventilated. The trachea will become colonised within two to four days, and the tracheal tube will then subsequently become colonised within two to five days.” Commenting on the six actions listed in the elements of care process of the recently updated HII for reduction of VAP, Dr Young first commented on the need to elevate the head of the bed to between 30°and 45° unless contraindicated.6 Although this recommendation was the HII most easily (and commonly) performed he did not think this was the most important care consideration, saying: “We elevate the head to stop regurgitation but this does not address the issue of colonisation.” He warned that head elevation alone was certainly insufficient. He believes that this HII was introduced to the care bundle on the basis of research which included too few patients and subsequent data (with larger patient numbers) has failed to verify the initial findings especially when a 45° elevation was not achieved. He considered oral hygiene to be of much greater importance in reducing the risk of VAP by virtue of reducing oral colonisation. Between 60% and 70% of the audience acknowledged that they used chlorhexidine regularly. The HII states that the mouth should be cleaned with chlorhexidine gluconate six hourly and, because it can be inactivated by toothpaste, a gap of at least two hours should be left between its application and toothbrushing.

The HII recommends that teeth are brushed 12 hourly with standard toothpaste. Dr Young also agreed that subglottic aspiration is an important element of the care process, while also acknowledging that there are clinical barriers to doing this. “Of 13 randomised control trials undertaken to look at this issue, 12 reported a reduction in VAP through subglottic aspiration. However, in most ICUs it is still not undertaken on a regular basis, as advised in the HII care bundle,” he said. On the issue of tracheal tube cuff pressure, Dr Young reiterated the HII advice and highlighted the importance of maintaining cuff pressure. “Over-inflation can cause problems to the tracheal wall.” He questioned how frequently cuff pressure should be measured. “If you measure too frequently you may be inadvertently causing the cuff to become under-inflated due to the use of measurement equipment which allows cuff deflation with repeated use (due to dead space) and inexpert use (by different people working on different shifts). Dr Young believes that a cuff pressure controller solution, which is able to continuously control cuff pressure, is the best answer to this problem, quoting a reduction in aspiration and VAP in recent work by Nseir et al in Lille, France. “This type of equipment is designed to correct the pressure automatically when the patient is moved and I expect that we will see more of this type of device being used in the ICU in the near future,” he said. Dr Young also commended the audit tool on the new HII which, he said, offers a useful facility, enabling observation of what is being done, and enabling compliance measurement. However, one important element that Dr Young feels was missed from the HII care bundle is that of tube management. “Even though this is not included in the HIIs it is still a vitally important consideration. Contaminated tracheal tubes can be a cause of re-infection following the use of antibiotics because the antibiotic effect will never reach the inside of the tracheal tube so any colonised matter here could still lead to re-infection.” Dr Young also referred to data relating to heat and moisture exchange filters. Historically, data suggested that these may improve VAP rates. However, with advances in technology heated humidifiers now have better control systems and heated ventilator circuits. This reduces condensation and ‘rain out’ in the circuit and VAP is no longer caused by heater humidification. There is evidence that lungs are better protected and that tube blockages are less with heated humidifier circuits and so these newer circuits are to be recommended (over HMEs) for critical care patients.