Background
Computed tomography coronary angiography (CTCA) is an increasingly common medical imaging examination. This is primarily due to its excellent negative predictive value in ruling out coronary artery disease (CAD).1 However the image resolution and hence diagnostic outcome is restricted partially by the ability to image the heart in motion. Electrocardiogram (ECG)-gating is employed to analyze image data at particular points throughout the R-R interval (usually the end diastolic phase or 75% of the R-R). The R-R interval is defined as the peak of one QRS complex to the peak of the next and in the case of ECG-gating is automatically identified by the scanner. This allows images to be reconstructed and visualized between contractive sequences. For this to be achieved, the patient's heart rate (HR) must be slow and regular enough for a predictable and motion-free image to be produced. Depending on scanner technology and scan parameters (and associated techniques used), this target HR will vary, but there is general consensus that as a minimum requirement a HR less than 65 beats per minute (bpm) is required.2
It is well accepted that appropriate patient preparation is key in order to achieve a diagnostic outcome. This includes appropriate patient HR control premedication. The Society of Cardiovascular Computed Tomography (SCCT) have proposed specifications for equipment, staff, service, quality assurance, patient selection, patient preparation as well as interpreting and reporting.3 These guidelines are based on expert opinion and meta-analysis.
In practice, the type and administration route of HR control premedications vary between departments. [beta]-blockers are utilized most commonly for this purpose. Both oral and intravenous (IV) administration protocols have been described with varying success.4-6 Alternatively, sino-atrial node inhibitors have become increasingly utilized for CTCA, particularly in oral form. Sino-atrial node inhibitors have the main advantage of reducing HR without an adverse effect on systolic blood pressure. As the two most commonly used medications for HR control in CTCA, the term HR control medication will be used to refer generally to beta-blockers and sino-atrial node inhibitors. These HR control medications are considered safe in this context, with very low rates of adverse reactions (0.19%-0.44%) associated with contrast media identified.7,8
This best practice implementation project was conducted at a single site in a generalist teaching hospital in regional Australia. The hospital has approximately 300 beds and is the major secondary referral centre for the health service district. At the time of this study, the Medical Imaging Department operated a single CT scanner, performing approximately 35-40 scans per day. The CT Scanner was a 64 detector-row scanner (Philips Brilliance, Netherlands) capable of retrospectively-gated CTCA only.
Up until the time of the study, it was practice at the Medical Imaging department to defer the type, dose and rate of administration to the judgement of the Cardiology Registrar on duty. However, this method was frequently problematic as the Cardiology Registrar (often a Medical Registrar on a Cardiology rotation) generally had limited experience with the examination technique and more specifically HR control medication administration in the CTCA setting. The practice therefore was not evidence-based. This practice had the potential for compromised service delivery due to a lack of efficiency in resource allocation. Furthermore, an increase rate of non-diagnostic results or the incursion of radiation doses higher than would otherwise be required were also of concern. A best practice guideline was sought to inform clinician judgement thus optimizing resource allocation of staff and scanner, reducing radiation dose and improving diagnostic integrity.
A number of criteria were audited in this project to assess compliance with current best practice in the preparation of CTCA patients with HR control premedication. These audit criteria were informed by the JBI evidence summary (see Table 1).
The CT Team Leader Radiographer was the project lead for the investigation. In conjunction with key stakeholders, an institution-specific guideline was created using the best available evidence gathered from a JBI evidence summary.
Aim and objectives
The aim of this evidence implementation project was to promote evidence based practice in the effective use of HR control medication in CTCA in order to achieve optimal diagnostic efficacy and improve resource efficiency.
The specific aims were:
* To undertake a baseline audit to identify current practice surrounding HR control medication administration in CTCA.
* To identify and engage a multidisciplinary team to assist in promoting best practice in the management of HR control in CTCA.
* To reflect on the results from the baseline audit and design and implement strategies to enhance compliance with best practice in the management of HR control in CTCA.
* To undertake a follow-up audit, assess the extent and nature of increased compliance with best practice, and identify areas and strategies to sustain and enhance care in the delivery of HR control to patients undergoing CTCA.
Methods
The Joanna Briggs Institute have validated the Practical Application of Clinical Evidence System (PACES) and Getting Research into Practice (GRiP) audit and feedback tools to assist with best practice implementation projects. This project used these tools which involved three phases of activity:
1. Establishing a team for the project and undertaking a baseline audit based on criteria informed by the evidence.
2. Reflecting on the results of the baseline audit, and designing and implementing strategies to address non-compliance found in the baseline audit informed by the GRiP framework.
3. Conducting a follow-up audit to assess the outcomes of the interventions implemented to improve practice, and identify future practice issues to be addressed in subsequent audits.
Ethics approval was waived as the project was considered a quality improvement activity and therefore exempt from scrutiny by a full Human Research Ethics Committee.
Phase 1: Stakeholder engagement (or team establishment) and baseline audit
The initial phase of the project (Phase 1) required the establishment of a project team consisting of various stakeholders in the management of the CTCA service. By engaging team members early in the process, a more fluid implementation with fewer barriers was possible.
The stakeholders identified as directly relevant to this project were:
CT Team Leader Radiographer
(Associate) Nurse Unit Manager
Quality Control Officer
Director of Medical Imaging
Cardiology Registrar.
The CT Team Leader acted as principal investigator for the project. Assistance was required from the Quality Control Officer to assist with the chart documentation audit process. The key roles of the (Associate) Nurse Unit Manager, Director of Medical Imaging and Cardiology Registrar were to inform the project and ensure maximum compliance from staff at the implementation stage.
Assistance was also sought from:
Director of Radiology
Director of Cardiology.
Assistance from these parties was largely consultative, but their approval was required in order to implement changes to standing orders and therefore change policy in HR medication administration and documentation.
Following the development of an evidence summary, associated audit criteria were created.9Table 1 shows the evidence informed audit criteria used in the project. For the first three criteria, a single sample = 1 institution was collected for each audit (specifically, whether or not an institution specific guideline was in place for those criteria). For audit criteria 4 to 10, samples = 12 patients were collected for the pre-implementation audit. Each sample related to a specific patient undergoing CTCA who required HR control medication to be administered. A "hand search" of patient charts was conducted in the initial phase in order to identify these criteria. Where documented evidence was not easily identifiable, a "No" was recorded for that audit criteria.
A timeframe of four to six weeks was selected for each of the pre- and post-implementation audits. This estimate was based in the performance of two to three CTCA examinations per week at the Toowoomba Hospital Medical Imaging Department at the time of the study.
Phase 2: Design and implementation of strategies to improve practice (GRiP)
The objective of the second phase of the implementation project was to gauge staff awareness of best practice and implement strategies in order to increase compliance with the outlined measures. This stage was guided by the GRiP tool. The identified barriers, strategies and their associated outcomes are outlined in Table 2. Two barriers were quickly identified as a result of the baseline audit: firstly, that no institution specific guideline to meet the first three audit criteria existed at the time of the baseline audit and secondly, there was not a standard documentation process to identify audit criteria 4-10.
Two key strategies were established to improve compliance with best practice. An institution specific guideline was required. The CT Team Leader Radiographer was made responsible for drawing up this draft work instruction. Direct consultation was then received from the (Associate) Nurse Unit Manager and Director of Medical Imaging. Finally, a formal draft was sent to the Directors of Radiology and Cardiology for their acceptance and feedback or for further discussion. The documents were tabled at a meeting prior to the creation of the final draft. This collaborative approach ensured wider acceptance of the strategy which was then published on the internal electronic publishing service at the district health service level.
The second strategy was to create a worksheet to improve documentation practices amongst staff. The worksheet was located in the CT department and consisted of a single two-sided A4 sheet with tick boxes for simple completion. The purpose of the worksheet was to simplify and enhance auditing methods, but also to act as a reminder to clinical staff to ensure the correct protocol was being followed.
Phase 3: Follow-up audit post implementation of change strategy (percentage compliance)
In the post-implementation phase, a separate data collection method was used. A specific worksheet was created to encourage improved documentation practices. This greatly simplified the follow-up search method required to identify audit criteria.
Data for the sample (n = 7 patients) was collected in the post-implementation audit. The same evidence based audit criteria were used in both pre- and post-implementation audits. A comparison between the pre- and post-implementation audits was done in terms of percentage of compliance.
Results
Phase 1: Baseline audit
The results of the baseline audit are shown in Figure 1.
As indicated, Criterion 6 relating to documentation of the type of HR medication administered showed good compliance with 10 of 12 samples (83%) receiving a "Yes" for compliance. Criterion 8, relating to the documentation of dosages, was less compliant with four of 12 samples (33%) receiving a "Yes" for compliance. Criterion 4, relating to the documentation of the reason for HR control medication administration, identified very limited compliance with only two of 12 (17%) receiving a "Yes" for compliance. All other audit criteria received a nil score for compliance in the baseline audit. The first three audit criteria related specifically to an institution specific guideline (n = 1). At the time of the baseline audit no such guideline existed. Therefore a nil score was recorded for compliance in each of these three criteria.
Phase 2: Strategies for GRiP
Table 2 shows the barriers identified from the initial baseline audit and the strategies used to overcome them. Resources and ensuing outcomes were also presented.
As shown, three important barriers were identified from the GRiP process. Initial priority was given to creating an evidence based institution specific work instruction for the department. This was acknowledged as the key strategy as it directly affected compliance outcomes for Criteria 1-3. Furthermore, the stakeholder group felt a work instruction in the form of a worksheet to capture the specific data required for documentation was important for informing staff.
Due to the limited time frame of the project, the stakeholder group agreed that the best way to create a work instruction was to base it on existing standards from the literature. A United Kingdom (UK) document produced by the Royal College of Radiologists, which created a national standard in the safe delivery of CTCA, was used.10 Further information was sought from the literature where it was felt the UK standards were not relevant to local practice, or where more detail was required. This included information in relation to sino-atrial node inhibitors in the CTCA setting as well as institution specific detail such as those relating to the CT scanner make and model, and staff capability.11-15
An associated worksheet was created. The stakeholder group agreed that a single A4 worksheet that was easy to follow and required minimal time was the best way to gain compliance with audit criteria. The worksheet was carefully constructed to adhere to all audit criteria whilst remaining relevant to the institution specific work instruction.
The third identified barrier was staff unfamiliarity with the policy documents and worksheet. The stakeholder group felt that the internal website was the most appropriate place to house these documents. However, a longer than expected delay in creating the document meant that it was only made available in draft form on the local hard drive at the time of the study. This caused slight problems initially and required the CT Team Leader Radiographer to remain vigilant in informing staff of its existence.
Phase 3: Follow-up audit(s)
The results of the post-implementation audit are compared with the pre-implementation (baseline) audit in Figure 2.
Figure 2 illustrates an improvement in compliance when compared to the baseline audit for all criteria. Most notably, a "Yes" was recorded for compliance for Criteria 1-3 (n = 1) relating to the creation of an institution specific guideline (100%).
A hundred percent compliance was also achieved for Criterion 8, related to the documentation of dosages, an increase from 33%. Criterion 6, relating to the type of HR control medication, was improved in compliance from 86% to 100%.
An increase from 0% to 86% was achieved for Criterion 4, relating to the documentation of the necessity for HR control medication. Criterion 5, relating to the documentation patient screening, increased from 17% to 86%. Criterion 7 showed the same increase, relating to the route of administration, as did criterion 9, relating to documentation of the patient monitoring procedure.
Criterion 10, relating to the post procedural care, was shown to be the least compliant at 57%. However this rate was an increase from the nil compliance at the baseline audit.
Discussion
The project was effective in achieving its objectives. An improvement in compliance was identified for all criteria assessed. However, challenges still exist in educating staff about the importance of documentation, particularly in post procedural care (Criterion 10).
The variation in compliance for Criteria 4-10 of the baseline audit may be explained by some nursing staff explicitly documenting the doses given in a medication chart as expected in their roles elsewhere, as opposed to others who believed the need for medication documentation was covered under the "standing order" of the clinical protocol. This is current practice when injecting iodinated contrast media for CT examinations. Of particular note, nursing staff were most diligent in documenting the type of HR control medication administered (Criterion 6 - compliance 83%), the doses of medication required (Criterion 8 - compliance 33%), and patient screening (Criterion 5 - compliance 17%). Whilst the pre- and post-procedural care such as patient monitoring as well as the necessity of HR control administration followed proper procedure in all cases (Criteria 4, 7, 9 and 10), it was not documented and therefore received a nil compliance score. This may possibly reflect a lack of awareness surrounding the importance of recording follow-up observations despite the patients' apparent healthy appearance. Further education in this area would likely improve compliance.
Forming a collaborative team to create an institution specific work instruction proved challenging. Whilst initial interest was shown from stakeholders following the establishment of the audit criteria, the creation of the institution specific work instruction and associated worksheet was left largely to the CT Team Leader Radiographer. This delay impacted on the time available for data collection in the post-implementation audit. Additionally, a longer than expected delay in creating the document meant that it was not reviewed by the publishing team within the project timeframe and was only made available in draft form on the local hard drive. The limited availability of the work instruction likely had a small impact on staff compliance. More importantly, the lack of formal education and communication with staff meant that not all staff were aware of this policy and worksheet existence, and compliance likely suffered as a result. This is despite the CT Team Leader Radiographer being present during all audited CTCA examinations. Whilst the post-implementation results were positive, the direct observation of staff may have inadvertently created some bias. A further follow-up audit in six months to a year is suggested to see if there is a drop-off in compliance.
There were some small issues identified with the post-implementation audit. Following the initial meeting with stakeholders discussing the evidence summary and audit criteria, an increasing number of patients referred from the cardiology department had been administered oral HR control medication prior to arrival in the Medical Imaging department. This reduced the number of patients requiring HR control medication administration within the department and hence the number of samples available in the follow-up (post-implementation) audit.
Additionally a change in scanner technology (the introduction of a new more advanced CT scanner) during the implementation phase meant that the requirements for HR control medication changed. Whereas a HR less than 60 bpm was considered essential for the 64 detector-row (Philips Brilliance) scanner, the new scanner (a 320 detector-row Toshiba Aquilion ONE) meant that the HR tolerance was higher (less than 65 bpm) and therefore the requirement of HR control medication was smaller.
Newer scanner technologies bring with them enhanced acquisition techniques allowing a smaller requirement for HR medication. This has allowed more successful imaging even at higher and more variable heart rates. However, currently the requirements of heart rate medication in CTCA are still important as the ability to image higher, more variable heart rates successfully comes at the expense of an increased radiation dose to the patient.
This best practice project highlighted the need for accurate documentation when administering HR control medication. Whilst a high degree of compliance resulted, the associated outcomes were not measured. Further study is therefore suggested to define precisely how implementing an improved documentation practice effects diagnostic outcome, radiation dose and workflow efficiency.
For all criteria, the post-implementation audit showed improvements in compliance with documentation regarding the use HR control medication in CTCA.
Finally, there is no international consensus about the most effective use of HR control medication in CTCA. The type of medication, dosages and route of administration vary considerably in the literature and in practice. Whilst a systematic review may be possible to clarify this, the necessity of HR control medication administration is reliant on the specific scanner technology and staff capability. Therefore further study will always be limited in scope. The development of an institution-specific policy sensitive to these factors is felt to be more important.
Conclusion
Following the creation and implementation of institution-specific evidence-based resources relating to HR control in CTCA, a high level of compliance consistent with best practice was achieved. Further work is required to identify how improved documentation practices following current best practice in the literature affects diagnostic capacity as well as resource and workflow allocation. Best practice HR medication administration in CTCA is strongly dependent on the specific healthcare environment and technology.
Acknowledgments
The author wishes to thank the Toowoomba Hospital Foundation and the Right to Private Practice Foundation at Toowoomba Hospital for assistance in funding participation in the JBI Evidence Based Clinical Fellowship Program.
Thanks to colleagues within the Medical Imaging Department and Department of Cardiology at the Toowoomba Hospital. Special thanks to Dr Penelope Astridge, Ms Natasha Ryan, Ms Lorraine Reynolds and Mr Aiden Cook for their assistance. Thanks also to the opportunities and assistance provided by Dr Catalin Tufanaru, Ms Alexa McArthur and staff at JBI.
References