Simple Emergency Cardiac Sonography: A New Application Integrating Lung Ultrasound

Abstract

We use the best of our 1992 Edition, Chap. 20 (the heart), born from the privilege of having been working in echocardiography in a pioneering institution [1], a typical spirit of intensive care, a discipline aiming at reaching its autonomy.

The heart, this organ that prevents us to examine the lung…. Ph. Biderman (December 26, 2007)

Appendix

1. Heart Routes

The left parasternal route is, as labelled, the left parasternal area (2010 Ed, Fig. 22.1). The apical route corresponds to the systolic shock. The left positioning is not easy in a ventilated patient. Mechanical ventilation often creates a hindrance to the transthoracic approach of the heart, and the subcostal route has been widely used in sedated supine patients. This is an abdominal approach, with the probe applied just to the xiphoid, body of the probe applied almost parallel the abdominal wall.

2. Measurements

Only rough estimates (some possibly obsolete) will be given. In a short axis at the pillar level, the LV walls (septal or posterior) are 6–11 mm thick in diastole. The LV chamber caliper is 38–56 mm. The RV free wall is less than 5 mm thick. A precise measurement of the RV volume should include subtle criteria, since its shape is complex.

An M-mode image through the LV small axis can measure (2010 Ed, Fig. 22.8) the LV chamber dimension in diastole, which indicates a dilatation, and this dimension in systole, which defines contractility. The difference of these two values, divided by the diastolic dimension, defines the LV shortening fraction, a parameter of the ventricular systolic function. It is normally 28–38 %.

The parietal thickening fraction (the ratio of the difference of diastolic and systolic thickening over diastolic thickening, normal range from 50 to 100 %) is less useful in our day (and above all night) routine.

3. Pericardial Tamponade

Some signs in concert with cardiac and respiratory cycles can be observed, in spontaneously breathing patients. Inspiration facilitates venous return, and the right ventricle dilates at the expense of the septum, which is more compliant than the free wall. The septum is shifted to the left and compresses the left ventricular chamber. Diastole creates a decrease in intracavitary pressures, whereas intrapericardial pressure remains constant. The right chambers are thus collapsed by the surrounding pressure. The right auricle wall collapses first, then the right ventricle.

The description of signs using Doppler would have a beneficial effect: showing physiopathologic patterns. It may also complicate the design, if time is wasted, if too sophisticated units are used, and if the operator is not trained enough.

Anecdotal Note

• 1. Hypovolemia

Traditionally, for diagnosing hypovolemia in a shocked patient, the heart is the main target (with Doppler and TEE). This textbook focuses at the lung – especially in extreme emergency and/or if no cardiac window is available. In the FALLS-protocol and SESAME-protocol, hypovolemia is defined by an A-profile (associated if possible with the ultrasound detection of massive free fluid).