What happens when a BLUE-protocol is performed or when any ultrasound test is done on a critically ill patient?

First, we see an “unusual” patient. Unusual is a term from the traditional perspective of the radiologist or the cardiologist. Our patient is in high distress (dyspneic, agitated, etc.) or already sedated. As opposed to ambulatory patients, who can be positioned laterally with inspiratory apnea for studying the liver, or sitting for pleural effusions, or again with legs down for venous analysis, etc., no cooperation is awaited. Apnea cannot be obtained: the patient is either mechanically ventilated, or dyspneic, or encephalopathic.

Usually, lung ultrasound in a dyspneic patient is perfectly feasible using our unsophisticated, instant response system.

The barrier is lowered. We don’t need to tear away the electrodes because our nurses have been taught to apply them at nonstrategic areas, i.e., the shoulders and sternum. The ECG is not disturbed. This slight detail makes one less useless loss of time (and costs).

Now, just before scanning our patient, we can note a remarkable and providential feature of ultrasound in the critically ill: most can be done in the supine position. The supine patient offers wide access to the most critical areas: the optic nerve, maxillary sinus, anterior and lateral areas of the lungs, most deep veins, heart, abdomen, etc. Turning a patient 90° is never easy nor fully harmless nor fast (and the BLUE-protocol is a fast protocol). The “hidden side” of the ventilated patient, i.e., the posterior disorders (effusion, consolidation), is a usual limitation, which we deeply reduce by optimizing the tools for making this setting like any other. The choice of our unique 88-mm-long probe is the main key for reducing the hidden face of the lung. For assessing the PLAPS-point (detection of most pleural effusions and posterior consolidations), the elbows are gently spread from the chest in order to facilitate a slight rotation.

Then, the scanning begins. With our compress soaked with Ecolight on the patient’s skin (the bed would “drink” it and oblige to more soakings, i.e., loss of time) and our probe in hand, we scan what is required: the lungs and the veins for the BLUE-protocol and the heart first for the FALLS-protocol. We follow standardized points for expediting the protocol and make more comprehensive scanning once the clinical question is answered (time permitting). Each change of area (e.g., from deep lungs to femoral veins) takes two seconds: no time for swapping the probe and no time for taking the bottle of gel; we just take our soaked compress and treat the next area to scan. We always use both hands, permanently.

In good conditions, the whole body can be analyzed in less than 10 min using our probe (the BLUE-protocol takes 3 min or less; sometimes it is concluded after 5 s). The examination can be recorded in real time without losing time taking figures. When the question is focused (e.g. left pneumothorax or not), a few seconds are required. Table 4.1 shows a suggestion of ultrasound report made with this spirit.

The critically ill patient is – in a way – privileged with respect to ultrasound. The sedation facilitates all interventional procedures. Traditional obstacles (the gas barrier) turn into advantages since lung ultrasound is the main topic of this textbook. Our study showed a 92 % feasibility for all usual targets [1].