Contrast Echocardiography-A Standard of Practice

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Abstract

Purpose: Contrast echocardiography is a valuable tool that allows significant improvement in image quality. However, approximately 20% of echocardiograms performed remain technically limited and non-utilization of contrast is most likely due to workflow concerns and/or processes-related implementation. This article will focus on minimizing barriers, thereby allowing incorporation of contrast enhancement as a necessary and vital standard of practice. Findings: Several studies have clearly illustrated the benefit and safety of contrast enhancement for improving both endocardial border definition and diagnostic confidence of the physician. Studies have also shown contrast enhancement to be efficient, cost-effective, and capable of positively altering patient management in terms of medical management and/or the need for additional imaging. Although contrast enhancement is undoubtedly advantageous, it remains underutilized. Summary: There are several best practice examples noted in the literature. These best practices outline the steps to overcome the difficulties related to contrast enhancement, such as additional support for starting intravenous (IV) therapies, administration of the contrast, and standing orders with defined protocols and criteria for patient safety.

Disclosure
Marti L McCulloch, BS, MBA, RDCS, FASE, is on the advisory board of Siemens Ultrasound and the speakers' bureau of Lantheus Medical Imaging. Robert J Davis, RCS, has no conflicts of interest to declare.
Correspondence
Marti L McCulloch, BS, MBA, RDCS, FASE, Director, Methodist DeBakey Heart and Vascular Center, The Methodist Hospital, 6565 Fannin, F9-093, Houston, Texas. E: mlmcculloch@tmhs.org
Received date
21 August 2009
Accepted date
06 October 2009

The cardiac imaging field has experienced significant improvements over the last decade due to technological advances. Cardiac computed tomography (CT), cardiac magnetic resonance imaging (MRI), nuclear cardiology, and echocardiography have all become feasible imaging modalities for physicians to evaluate in order to answer specific diagnostic questions. Each of the aforementioned modalities has strengths and weaknesses, but only echocardiography is radiation-free, will not induce claustrophobia, and is not bound to respiratory or rhythm gating. However, it does have certain limitations in terms of image quality due mainly to body habitus. In order to remain competitive with the high-resolution image quality of other modalities, the field of echocardiography must embrace contrast enhancement. Although contrast echocardiography has been clinically available for over a decade, the acceptance rate by professionals in the field has been limited by barriers in terms of the process of incorporating contrast into daily practice. The literature supports innovative approaches, such as maximizing resources (intravenous [IV] certification and contrast competency), concise policy and procedures, and protocol-driven standing orders. The purpose of this article is to highlight best practice sharing in an effort to encourage contrast enhancement and incorporate it throughout all echocardiography laboratories as a standard of practice.

Maximizing Resources

The major limitations of contrast implementation in an echocardiography laboratory typically involve the division of labor and responsibilities and the additional time and effort it takes to perform the contrast exam.1–5 While efficiency and labor remain valid administrative concerns, providing a quality study for diagnostic accuracy must be the primary focus for superior patient care. In an effort to drive quality while maintaining efficiency, cross-training staff to perform these additional functions is a helpful option. IV access is required for the administration of contrast and typically outpatients do not have such access. Therefore, echocardiography laboratories that do not have or that are in short supply of nursing staff may opt to cross-train other medical staff to assist with IV insertion.5–7 Many associated health professionals are trained in venipuncture, including phlebotomists, emergency medical technicians, radiology, and nuclear medicine technicians.2 IV insertion is a proficiency that can be obtained by most medical staff, including stress technicians and cardiac sonographers.1–7 IV certification typically involves didactic training coupled with practical, hands-on experience.

A certificate of completion is earned after passing a test for comprehension. Once the education is complete, the laboratory or facility determines how many contiguous, successful IV insertions are required in order to be signed off. Thereafter, an in-service with a competency checklist needs to be performed annually.
There are several approaches to IV certification including online courses, local community college classes, or a DVD with workbook (a nurse teaches this course). To date, there are no national standards for IV certification; rather, each state board of nursing may have standards that apply to nurses and/or each employer may have additional requirements. Fortunately, many ultrasound schools are incorporating IV insertion and contrast administration into their core curriculum, which serves to further contrast echocardiography as a standard of practice.6 In addition to IV certification, the literature also supports the cross-training of sonographers to administer contrast provided there are appropriate policies and procedures in place with documented training and competency.1–2,4–6 Implementation of sonographer contrast administration will vary depending on state and local regulation, facility standards, and the general level of acceptance. However, there are favorable consensus statements, guidelines, and other supportive literature that may be drawn on to convince any detractors that the sonographer administration model is sound and viable.1–8 Facilities that have the concept in place typically have strict criteria for administration that focus on patient safety. For example, the criteria may dictate that only registered sonographers with appropriate documented training may administer contrast under the direction of the medical director with a patent IV port not actively used for other medications. Another example could be the documentation of an IV certification course and competency checklist for any technical staff performing IV insertion. The medical director of the echocardiography laboratory needs to be the major driver in the process implementation and must have a trusting relationship with the staff.1

Concise Policy and Procedures

Policies refer to the rules or guidelines for implementation, whereas procedures correspond to the implementation of a policy. Policy and procedures are meant to be updated on a regular basis in order to accommodate the changing external environment. Depending on the laboratory and facility, policy and procedures may need to be vetted through the medical director and/or a policy and procedure committee.

Generally, administrative managers and/or directors update echocardiography laboratory policy and procedures with the input and feedback of the medical director and medical staff. To implement a new policy guideline such as IV certification or sonographer contrast administration, there must be concise language in the procedure section that clearly outlines the process. Sonographers, nurses, and physicians should all be aware of the indications for contrast, injecting and imaging protocols, monitoring, and personnel responsibilities.9

Protocols, Checklists, and Standing Orders

Protocols ensure process compliance and are an adjunct to the policy and procedures. A contrast protocol allows for standardization of contrast utilization by following the defined criteria. For example, the American Society of Echocardiography recommends use of contrast when unable to visualize two or more wall segments.1,3 In addition, the facility may want to consider implementing a safety checklist to identify patients with contraindications (known or suspected shunts, hypersensitivity to perflutren, or pregnancy) or who may require additional monitoring (unstable cardiopulmonary conditions or pulmonary hypertension). Additional education will benefit inpatient and intensive care unit (ICU) nursing staff outside of the echocardiography laboratory who may be reluctant to give contrast to unstable patients. The education should provide an understanding of the need for contrast, its established safety, and that subsequent patient monitoring is routine and does not present an additional burden. Consent for contrast administration depends on state mandates and/or facility standards. Always follow the guidelines of the manufacturers when utilizing any medication and assess all patients for any condition that may preclude the use of contrast. Facilities that frequently use contrast may benefit from putting a system in place where the sonographer identifies contrast need and initiates its utilization. Castello et al. have shown the efficacy of a sonographer-driven contrast protocol to reduce patient wait time and the improve diagnostic confidence of the physician. Accordingly, Castello et al. believe the sonographer should be authorized to initiate the utilization of contrast with a standing order. This eliminates the need to obtain a physician order for contrast, greatly reduces the number of uninterpretable studies, and improves wall-motion analysis.3 In the absence of a medical director, individual cardiologists may be contacted to ascertain willingness to create a standing contrast order for patients they refer for testing or for exams they interpret.

Outline of Required Elements for Contrast Adoption

A number of elements have to be considered when considering contrast adoption, including:

  • discussion and review of logistical and legal hurdles to process implementation with consensus among involved parties (e.g. administrator, medical director, technical staff, etc.);
  • creation of policy and procedures in terms of contrast use and administration;
  • development and adoption of administration protocols for contrast with provisions for contraindications, patient safety and additional monitoring;
  • cross-train and educate staff in IV certification, contrast administration, etc.; and
  • standing orders for contrast administration as deemed by sonographer (optional but recommended).

For additional resources, tools, and examples, please visit the Contrast Zone at www.asecho.org

Conclusion

Although contrast media in echocardiography has been available for over a decade, the widespread adoption of its use has not occurred. Myriad studies have proved that contrast enhancement reduces exam redundancy, improves diagnostic confidence, and can alter patient management and/or the need for additional diagnostic imaging. Transpulmonary contrast for echocardiography is unlike contrast dyes, chemical compounds, or radioisotopes that are used in other imaging modalities, and has an established safety record. The contrast consists of stabilized, gas-filled microbubbles that resonate when struck by ultrasound. There is a wealth of evidence to validate the benefit of incorporating contrast echocardiography as a standard of practice. Maximizing departmental resources by cross-training staff, implementing policies and procedures, and devising protocols and standing orders can all make this beneficial and necessary transition in echocardiography a seamless one.3–11

References
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