Discussion

The routine practice of daily CXRs on all patients receiving IMV in the ICU originated from collective expert opinion claiming a high rate of unsuspected findings detected by routine CXRs in this patient population,1–3 and was up until recently supported by the American College of Radiology (ACR).12 13 However, studies in surgical ICUs found low detection rates of clinically significant, unexpected findings, leading some investigators to conclude that daily CXRs in the SICU should only be obtained when clinical necessity is suspected.14 15 Graat and colleagues demonstrated that only 5.8% of routine daily CXRs in a mixed medical and surgical ICU revealed unexpected findings, and only 2.2% led to a change in management.13 16 Others have since demonstrated a low diagnostic and therapeutic utility of routine daily CXRs in the ICU,4 and that a strategy in which CXRs are obtained only on clinical indication, when compared with routine practice, had no undesirable impact on hospital LOS or mortality.5 6 Since the completion of these reports, two meta-analyses have corroborated the safety of a more restrictive, indication-directed chest imaging strategy.7 8 In response, the ACR has since modified their position, now stating that routine daily CXRs in the ICU are unneeded and should only be obtained for specific clinical indications.12 However, this strategy has yet to be uniformly adopted.

Given current evidence, rather than set out to firmly establish the safety of an indication-restricted CXR strategy, we sought to change our local practice to one that would provide greater efficiency and value to our ICU practice. The findings in this study support our primary hypothesis that staff education and elimination of the ‘daily’ order option can reduce the number of potentially unnecessary CXRs, and hence increase the percentage of high-value CXRs. More specifically, we eliminated between 1089 and 1274 potentially unnecessary CXRs annually in our combined ICUs, equating to an estimated annual savings of around $200 000. Using CXR cost estimates published elsewhere,11 the savings could be higher than this and do not account for further reductions in downstream testing costs precipitated by false-positive CXR findings. Because we chose to normalise monthly CXR volumes to a ‘per 1000 IVDs’ ratio, and the number of IVDs actually trended down over the study period in both ICUs (figures 1 and 2), this in turn actually diminished our ultimate savings from avoided CXRs. Had the number of IVDs not decreased over the study, the savings would have been even greater.

Because CXRs were ordered only on the basis of a clinician-identified indication following our intervention, we feel it reasonable to assume that the resulting reduction in automated daily CXRs led to an increase in clinical value to those CXRs obtained following the intervention. Although we did not specifically set out to establish the safety of a more restrictive, indication-directed ICU chest imaging strategy, we were able to establish that there was no increase in the number of event reports related to missed endotracheal tube or central catheter malposition. Furthermore, there was no recognisable reduction in the overall quality of ICU care, at least as measured by ICU LOS and O:E mortality.

The absence of any event reports regarding unrecognised tube malposition likely points out a weakness in this secondary outcome and suggests an overall underutilisation of our event report system for these safety concerns. However, 39 reports of self/unplanned extubation were uncovered during the study period. When these events were normalised to IMV census days, rates actually declined from 6.4 to 4.2 unplanned extubations per 1000 IVDs in the MICU and from 2.3 to 1.1 per 1000 IVDs in the SICU. Thus, provided that there was no change in reporting habits, it does not appear that our change in practice led to any increase in unplanned dislodgements of endotracheal tubes.

In our efforts to change the local culture of practice in our hospital, we borrowed from the model developed at the Johns Hopkins Armstrong Institute of Patient Safety to promote the translation of evidence into practice: engage, educate, execute and evaluate.17 We began with engaging and educating our staff in both ICUs on the documented low clinical yield of automated daily CXRs. We then heavily borrowed from this model to execute our change in practice by redesigning the care process through standardisation, checklist-based prompts and developing a ‘hard stop’ in our ordering systems to eliminate the option for automated daily CXRs. Our system-based practice change also required a built-in prompt to avoid missing the opportunity for chest imaging when indicated, but this had to be simplified to facilitate its success. For example, in their efforts to reduce venous catheter-related bloodstream infections, by simply prompting the clinician to ask on a daily basis whether a catheter was still needed, Berenholtz and colleagues avoided the pitfalls of overcomplexity that arise from trying to develop strict inclusion and exclusion criteria that bypass clinical decision making.18 19 We likewise chose to avoid any complex algorithms that dictated when a CXR was or was not indicated, and simply prompted clinicians daily to order a CXR when circumstances were felt to warrant one. This, alone, led to a 64% reduction in ordering habits in the MICU. We believe this also helped to avoid the potential for underutilisation of clinically warranted CXRs, as an ‘out of sight-out of mind’ consequence of eliminating the ‘daily’ CXR option. Although we cannot prove that this daily prompt resulted in a lower number of missed conditions, our data suggest that this practice did not coincide with any increase in undesirable outcomes.

We also sought to reinforce the gradual adoption of practice change through regular monitoring (evaluation) of our primary outcome variable (CXRs/1000 IVDs). One might expect that by simply eliminating the ‘daily’ CXR option, we should have seen an almost immediate drop in CXRs. Instead, this process evolved over a 1-year period of time. This was likely in part due to the staggered roll out of our interventions, with changes in our EHR-based orders and daily checklist occurring months after beginning efforts to engage and educate staff (figures 1 and 2). However, our team also anecdotally noted that this process of practice change required championing on the units, with frequent re-education of staff. At first, when radiology staff arrived on the units in the morning without orders for CXRs on every patient on IMV, they would often prompt residents to place an order for what was interpreted as an error of omission. This habitual ‘local culture’ practice took time to extinguish through reminders and re-education. As success in reducing our rate of CXRs on non-admission, non-procedural census days was fed back to staff, these positive outcomes helped reinforce our change in practice.

We should also acknowledge that a quality initiative will likely achieve more universal buy-in from staff when the effort seeks to eliminate waste in resources and time rather than building on the already high burdens of work and documentation imposed on hospital staff. Experts assert that working ‘smarter, not harder’ is the better approach to improving quality in healthcare,20 pointing out that in industry, the ‘work harder’ approach can often bridge performance gaps in the short run, but are often not sustainable.21 For instance, best practice bundled care for prevention of ventilator-induced pneumonia has been estimated to add a median of 115 min per day onto the workload of nurses,22 perhaps helping to explain suboptimal compliance rates even within grant-funded research projects.23 In the current project, the low time investiture required from staff, and regular feedback on resources saved likely had a reinforcing effect on the outcome of our initiative.