Case 1 - A tail of one half...

EchoLung

19 Oct

Author: Nish Cherian Reviewer: Nick Mani

A 30-year-old male presents to ED with worsening dyspnoea for over 1 week. He is hypoxic at triage with SpO2 88% on room air. He has no medical co-morbidities and takes no medication, but reports recreational methamphetamine and cocaine use.

POCUS reveals the following:

Clips Gallery

Clip 1- PLAX, Clip 2- PSAX, Clip3- A4C, Clip 4- Lung US, Left (L4)

EPSS (E-point septal separation) - >7mm suggests impaired LV function (see example below)
LV fractional shortening - can be “eyeballed” or measured in PLAX, should be approx 1/4 or 1/3
Assessing thickening/contraction of myocardial walls
MAPSE (mitral annular plane systolic excursion) - <8mm indicates impaired LV function
Severely impaired LV systolic function (estimated EF likely <15%)
TAPSE (tricuspid annular plane systolic excursion) - M-mode through tricuspid annular plane (free wall), <16mm indicates reduced RV longitudinal function (see example below)
RV size - normal RV size is approx 60-70% of LV. A 1:1 ratio definitely abnormal and may be acute or chronic. Obstructive causes of RV failure (eg PE, pHTN) often cause dilatation and bowing of the septal wall into the LV.
These are ring-down artefacts (also known as “B-lines” in the lung). They are formed by sound waves interacting with an air-fluid interface (gas bubbles).
Sound waves trapped within gas bubbles cause them to resonate and produce a secondary sound wave which returns to the transducer and produces a continuous non-attenuating hyperechoic laser-beam like artefact.
B-lines/ring-down artefact in the lung indicate increased lung density - often due to extravascular lung water but may also be caused by inflammation and fibrosis. When diffuse and bilateral, involving more than 2 lung zones bilaterally it is termed an alveolar-interstitial syndrome.
In this case, the B-lines were due to cardiogenic pulmonary oedema.

Case resolution

This patient had severe biventricular failure secondary to likely methamphetamine-related cardiomyopathy. He was admitted to CCU and had a departmental echocardiography, which confirmed the diagnosis.

Take-Home Message

Bedside focused echo (often complemented with lung ultrasound), even qualitative, is a good screening tool for a competent operator in selected cases as an extension of standard asessment.

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