Lung Ultrasound as the First Step of Management of a Cardiac Arrest: The SESAME-Protocol

Abstract

In cardiac arrest, the SESAME-protocol proposes to scan first the lung for two major targets: pneumothorax and clearance for fluid therapy. This information can be obtained in less than 5 s, i.e., a minimal hindrance in the course of resuscitation.

The SESAME-protocol then scans the lower femoral veins and the belly (first if trauma), for detecting pulmonary embolism or massive bleeding.

Then a pericardial tamponade is sought for.

Cardiac causes then follow, in position 5.

Appendix 1: Our Adapted Technique for Pericardiocentesis

Technically, the cardiac compressions are discontinued, the subxiphoid area is disinfected, and the needle and the microconvex probe make a rather sharp angle (like 30°). Our special 60-mm 16 G catheter is used (ELSISCEC protocol, described in Chap. 34). Thick fluid requires larger catheters. The section on venous cannulation in Chap. 34 describes our extremely simple way of ultrasound-assisted procedures. No need for a 65-statement ICC, just check that the four points are aligned two by two, and go.

Now the needle is inserted, through some liver parenchyma (large vessels, clearly seen, are avoided). If the tip is lost, slight (millimetric) Carmen maneuvers find it back. When a metallic structure penetrates a large fluid rounded cavity, plenty of arciform artifacts can be generated (a “firework sign” should be a self-speaking term). The physician must concentrate only on the needle tip.

Our habit is to keep the end of the needle open, at atmospheric pressure, without syringe: the pericardial fluid under tension will spontaneously spout out (try to collect some fluid for analysis, and volume assessment). This allows to keep the needle in the pericardial sac and far from the heart. These good sense maneuvers simplify the technique.

Once fluid pours out, two options are possible: keep the entire catheter as it is, and withdraw it when a reasonable amount of fluid has been evacuated, in order to avoid harm to the heart (initially protected by the pericardial fluid). Or withdraw the metal part for making no risk of cardiac harm, but consider the obliquity of the needle tip (usually 4 mm) and secure this procedure by inserting at least 5 mm of needle within the pericardial sac. A syringe can be mounted, vacuum can be made (two operators may be wise, one firmly maintaining the catheter). According to the volume-pressure curve of the pericardium, a minimal amount is sufficient for fixing the adiastole, allowing a return of spontaneous circulation. If the pericardial effusion is 25 mm large, the first few milliliters of withdrawn fluid will decrease the pressure far more than the volume, and this is the target. If inserting 5 mm of the whole needle, there are still 20 mm (or slightly less) of safety distance from the heart. In the ultrasound domain, this is a comfortable margin.

Several other protocols may be imagined after – we let the user free of his/her own technique.