Portable echocardiography has the capacity to identify defects with comparable accuracy to standard machines, to change diagnoses and treatment and has facilitated early discharge in up to 50% of patients. While these figures may depend on the nature and profile of the patients screened and the skills available, in principal it validates the increased potential for patient care. This article discusses the potential applications of echocardiography to improving the efficiency and delivery of healthcare and the potential pitfalls that may be encountered.
Echocardiography in a Critical Care Setting
Starting with a patient’s journey before arrival during and after the emergency room, portable echocardiography has proven successful. In the Coronary Care Unit (CCU) in particular, it is not surprising that in the hands of cardiologists, portable devices could be used to assess areas such as left ventricular ejection fraction and pericardial effusions. This helps to prognosticate and triage patients to the most appropriate therapy immediately and reduce the immediate burden on departmental echocardiography.
Most studies in this
area have confirmed that portable echo almost inevitably changes or at least
consolidates clinical decisions made at the bedside. Portable machines have
also been used effectively in environments such as the catheter lab where
assessment of cardiac tamponade is often challenging and similar devices have
been shown to correctly address 90% of clinical questions in the ICU. This is
particularly surprising since the investigations were performed by ICU physicians
in patients that are traditionally regarded as challenging for standard echocardiography.
Echocardiography & Screening
An increasing role for echocardiography pertains to the screening of patients for occult or mildly symptomatic conditions for the prevention of disease. These investigations can be performed either in the community, at designated health screening centres or in hospitals. Moreover, the echocardiography can be combined with electrocardiography and biomarkers (e.g. BNP).
However, a characteristic feature of these screening programmes is the general trend to less direct involvement by doctors and a greater responsibility placed on sonographers.
A number of studies have shown the potential for such screening activities. One study showed that portable echocardiography was far superior to the clinical examination alone, almost doubling the number of cardiac anomalies detected (detecting ~70% of all such abnormalities and ~80% of all major abnormalities).
Similar studies have
confirmed that in community screening, portable echocardiography is as accurate
as standard departmental echocardiography in detecting cases of ventricular
dysfunction and left ventricular hypertrophy. These programmes have therefore
been demonstrated to be of significant clinical value, and are being rolled out
in a number of clinical centres.
Applications for portable echocardiography are diverse and immediate. However enduring question are; whether these scans approximate to those from standard departmental studies, whether they have a significant impact on patient treatment by more accurate prognostication, whether they lead to substantial changes in treatment and in outcome and finally whether they are cost-effective.
With respect to the first question, scans approximate to departmental scans under optimal conditions. The latter proviso is not insignificant as there is often a tendency to perform portable echos in suboptimal settings or in a more focused manner which will inevitably increase the rate of errors or omissions. Portable machines are now so advanced that the GE Vivid I and the Sonosite Micromax have tissue Doppler imaging and almost identical capacities to large departmental machines.
With respect to the
second question, portable echocardiography does have the capacity to
prognosticate, change treatment and potentially outcome. Finally, with respect
to cost-effectiveness, studies have confirmed that portable echo can confer major
time and cost savings. For limited or focused studies, portable machines have been
shown to confer substantial time, cost and hospital clinic and bed-occupancy
savings. Although precise cost calculations are heavily context dependant, at
least in general cardiology, portable echocardiography approximately halved the
price of an echo from 132 to 75 Euros.
Training Still a Contentious Issue
While there is
excitement that increasingly portable machines which will become ever more
available to practitioners, will mean major advances in patient care, there is
genuine concern that harm may be inflicted upon patients by untrained or inadequate
The question remains –
what is adequate training? This question is complicated by the fact that
different practitioners require different levels of proficiency and support for
their different applications.
At present, the American
Society of Echocardiography (ASE) require an exacting 150 portable exams, in
line with the exacting requirements of standard echo accreditation. The
rationale behind this approach is that portable echo may be even harder than standard
echo to interpret and that the practitioner may often be unsupported or have to
make decisions in real time.
The British Society of
Echocardiography (BSE) has also recently developed a structured approach to accreditation.
Detractors from such accreditation procedures have suggested that
non-cardiologists may not be able to achieve such numbers in a practical time
period and that many of the skills can be “learnt on the job” so long as
adequate support and attention to the limitations of the technique are noted.
Support for the latter position has come from studies with medical students
showing that a carefully designed short training programme can permit students
to make assessments of specific echo parameters rapidly and efficiently. Ultimately, the easy
availability and power of this technology suggests that there will be rapid
dissemination irrespective of these two polarised positions.
To ensure patient care
is not compromised, ideally, the accreditation programmes of the ASE and BSE
should be heeded. It is at least essential to have attended some form of formal
training programme with a handheld component. The operator should make diligent
attempts to spend time with an experienced sonographer and to operate in a department
with support, with respect to imaging and reporting. Ultimately, it is
essential that the operator document the report of the imaging clearly and emphasise
the fact the study was a portable study with the implicit limitations. This
will be particularly robust if the study is recorded for later retrieval if necessary.
While the future is bright for these machines, in order for them to entirely full fill their potential a concerted effort of cooperation will be needed from cardiologists, sonographers, and other physicians such as ancillary medical staff to ensure that patient care is not compromised. In this way, real-time cost-effective studies will improve immediate patient care, reduce waiting times and ultimately reduce costs.