An epidemiological study of ventilator-associated pneumonia (VAP) and ventilator-associated events (VAE) surveillance and preventative strategies in critically ill children

Abstract

Background: Ventilator-associated pneumonia (VAP) is an ongoing iatrogenic burden within the healthcare system for both adults and paediatrics. Debate continues over the appropriateness of the VAP surveillance tool in paediatrics. Implementation of the new ventilator-associated events (VAE) surveillance tool in the adult setting have shown to overcome the subjectivity of the traditional pneumonia 1 VAP (PNU1/VAP) surveillance tool. Unlike in adult units, the application of the VAE surveillance tool in paediatrics has not been mandated, leaving a question as to its potential application. The lack of VAP paediatric specific studies has hampered progress informing compliance with VAP preventative strategies in paediatric intensive care units (PICUs). Despite good hand hygiene practise being established as a vital infection control measure, perception of ‘Speaking up for hand hygiene’ in PICU still under- research. Hence, it became a potential area to improve good hygiene practice.Aim: To determine the VAP and VAE incidence using two surveillance tools at two time points; at baseline and post an education campaign aimed at both PICU staff and parents. In addition to testing the two surveillance tools, compliance auditing and staff and parental perspectives of VAP/VAE and preventative strategies was established.Methods: Retrospective study: PNU1/VAP and VAE surveillance tools were applied to 262 mechanical episodes of 234 children who received invasive mechanical ventilation ≥48 hours in PICU in 2015. The sensitivity and specificity of VAE surveillance tool was tested. Other epidemiological data were recorded; demographic characteristics, risk factors and VAP preventative strategies documented within the unit.VAP education, VAP compliance auditing with feedback and surveys: reinforcement of updated VAP education was launched for PICU staff, and a pamphlet focusing on ‘Speaking up for hand hygiene’ was developed primarily to educate parents. The information was delivered to parents (N=37) via a pamphlet and face-to-face education. VAP compliance auditing was conducted for a two-month period and involved 37 patients in PICU undergoing VAP preventative strategies implemented by PICU staff and parents: hand hygiene, oral hygiene, endotracheal tube (ETT) suctioning, ETT cuff pressure checks, head of bed elevation, ventilator circuit checks, and early enteral feeding commencement. The parents’ and nurses’ perceptions of ‘Speaking up for hand hygiene’ were examined through surveys undertaken by 19 parents and 34 nurses.Prospective study: a six-month prospective study was conducted to investigate any improvement in incidence rates of VAP/VAE and estimate the compliance rate of VAP preventative strategies.Results: The incidence rate of VAP/VAE was 9.3 per 1000 ventilator days (VAP/VAE) based on end of ventilation and 10.2 (VAP) and 10.4 (VAE) per 1000 ventilator days based on when the patients were no longer at risk. The specificity of the new VAE surveillance tool was high with a slight agreement between the tools. The overall compliance with VAP preventative strategies was 89.0%. The presence of gastrointestinal prophylaxis (GI) and the frequency of oral hygiene were predictors of the potential incidence rate of VAE/hour of ventilation, but none were found for VAP.Overall VAP preventative strategies compliance was measured at 83.1%. Hand hygiene compliance among PICU staff was at >80% and 64.7% among parents. Oral hygiene and ETT cuff pressure checks (sub-elements) reported a compliance rate of <80.0%. Parents and nurses agreed that the ‘Speaking up for hand hygiene’ initiative would increase hand hygiene practises and willingness to be reminded to perform the practise in PICU. Some parents reported reason being at vulnerable position to questioning, made them hesitate to remind nurses and other PICU staff to perform hand hygiene. Nurses reported their concern for the parents’ emotional status and preconceptions that their colleagues were unwilling to accept hand hygiene reminders as reasons for not reminding.The reduction of the incidence rate for VAP/VAE showed a drop to 3.9 (VAP) and 4.4 (VAE) and to 2.8 (VAP) and 3.2 (VAE) per 1000 ventilator days based on end of ventilation and until the patients were no longer at risk. There was a statistically significant improvement of VAP preventative strategies’ compliance reported between prospective and retrospective studies.Conclusions: The reduction of VAP/VAE incidence rates demonstrated in this study reinforces the need for VAP education, compliance auditing with feedback, and hand hygiene education for parents and staff. Surveys on ‘Speaking up for hand hygiene’ among parents and nurses provided improved perceptions which may help promote infection control measures in PICUs. Although the VAE tool had slight agreement with the PNU1/VAP tool, it suggested the merit of identification of non-VAP complications through a high specificity result. No risk factors or VAP preventative strategies were found to be predictive of VAP, although these factors may be potential factors for non-infectious complications. The presence of GI prophylaxis and frequency of oral hygiene performance were found to be associated with VAE development. These findings were not robust, due to the low events rate, but they were worthwhile predictors to be researched further.