The Increasingly Important Role of FoCUS at the Bedside

September 25, 2020

Written by Max Hensel

Spoon Feed
FoCUS (Focused Cardiac Ultrasound) enhanced diagnostic ability for multiple cardiac parameters when performed at the bedside.

Why does this matter?
Cardiac ultrasound is becoming more readily available as cost for machines decreases. Using this tool can help us with our exam and support proper management of patients moving forward.

FoCUS isn’t “Hocus Pocus”
This was a modified systemic review of prospective studies regarding the diagnostic accuracy of focused cardiac ultrasound.

In clinical assessment alone vs. assessment + FoCUS, overall diagnostic accuracy improved regardless of training level (experts vs trainees) as well as inpatient versus outpatient across multiple cardiac parameters.

Left Ventricular Dysfunction
In comparing classic history and physical findings of heart failure, sensitivities were low, but FoCUS resulted in a greater sensitivity (84% vs 43%) in the diagnosis of heart failure as well as a modest, but not statistically significant, increase in specificity (89% vs 81%).

Valvular disease
FoCUS also led to increased sensitivity for mitral and aortic pathology vs physical exam (71% vs. 46%), with similar specificities.

Pericardial effusion
One study showed emergency physicians had a sensitivity of 96% and specificity of 98% in identifying pericardial effusions in patients who were high risk. Even outside the ED, most studies had sensitivities ranging from 78-100%.

Right Ventricular Dysfunction
Echocardiography has prognostic importance in patients with pulmonary embolism (PE), but FoCUS should not be used as a tool to rule out PE in unselected patients. Rather, FoCUS appears to be most helpful in decision-making for patients with undifferentiated hemodynamic instability. The European Society of Cardiology notes, “the absence of RV dilation/dysfunction in hemodynamically unstable patients essentially excludes PE.” In a study of nearly 200 patients, more than 90% with a central PE had signs of right heart strain on FoCUS, with inter-rater reliability >95%.

Other Clinical implications
The impact of FoCUS on patients is significant. A review of three prospective observational studies of >400 patients found FoCUS changed management 37-51% of the time.

There are limitations in several of the studies reviewed, most notably the skill of the operator markedly impacts diagnostic yield. Despite this, the use of FoCUS can assist in the diagnosis and management of a spectrum of cardiovascular problems and is a technology that is here to stay. It will become cheaper, more readily available, and is a skill worth learning and utilizing to guide patient management.

Source
A Shifting Paradigm – The Role of Focused Cardiac Ultrasound in Bedside Patient Assessment. Chest. 2020 Jul 21:S0012-3692(20)31950-4. doi: 10.1016/j.chest.2020.07.021. Online ahead of print.

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Reviewed by Clay Smith