Ultrasound (US) is a noninvasive technique that offers an image of body organs and vessels for diagnostic and/or therapeutic purposes. It presents limitations depending on the indication, the technical capacity of the operator, the quality of the data obtained, and the decisions made.

The actions taken as a result of poor interpretation of the exploration can have adverse consequences for the patient. Likewise, failure to use the technique for diagnoses or invasive procedures may imply an unnecessary risk for the patient that can have legal consequences for the physician. Use of the technique implies adequate training.

Critical patients generally present a series of clinical particularities in which morphological and functional ultrasound evaluation proves essential due to its noninvasiveness, reliability, validity and applicability at the patient bedside (Table 1).There is extensive literature supporting the use of the technique in critically ill patients.1–5

The Spanish Society of Intensive and Critical Care Medicine and Coronary Units (Sociedad Española de Medicina Intensiva, Crítica y Unidades Coronarias, SEMICYUC) has the responsibility, duty and obligation to ensure that the procedures used in critical patients are carried out safely and correctly as regards their indication, quality and the technical knowledge of the operators, based on the implementation of an accredited training program.

In this context, the SEMICYUC should promote the use of ultrasound, facilitating its adoption as a routine tool, as well as correct training in the technique, with a view to ensuring that most Units have access to these procedures and that critical patients are treated and monitored effectively, adequately and safely. However, no widely recognized guidelines have been established to date, and only a few isolated national initiatives have developed rules for training in ultrasound among non-cardiologists who perform explorations in different settings,6–9 and particularly in Intensive Care.9

Of the possible clinical situations in which echocardiography may be indicated10 (about 200), over 50% are found in the Emergency Care area and in Intensive Care Units (ICUs).

The Cardiological Intensive Care and Cardiopulmonary Resuscitation Work Group of the SEMICYUC (GTCIC y RCP), on occasion of its XXVII meeting held in 2010 in Sabadell (Spain), decided to draft a consensus document supported by the most recent scientific evidence based on a search of the United States National Institute of Health, National Library of Medicine – MEDLINE, and recruiting the broadest national representation of intensivists with extensive experience and knowledge of ultrasound. During this period, it proved possible to increase the number of authors collaborating in the initial draft, which in turn was presented in the scientific meetings of Segovia in 2011, Santander and Madrid in 2012, and Tenerife in 2013, until its definitive presentation for publication.

This consensus document describes the characteristics of ultrasound in general and of echocardiography in particular, in reference to the management of critical patients. The ultrasonographic studies are delimited according to levels and the recordings included, with consideration of the training needed by non-cardiological specialists in order to acquire the necessary skills.

One of the aspects in which maximum consensus was gained in our group was the notion that general ultrasound training in Critical Care Medicine and training in basic echocardiography should start during residency training. Furthermore, it should range from “first sight” exploration and the concept of discarding life-threatening disease (“rule-in versus rule-out”) to more precise and specific evaluations. The topics addressed in general ultrasound training in Critical Care Medicine are pleuropulmonary ultrasound, vascular ultrasound, transcranial duplex imaging and ultrasound in the context of different protocols: focused assessment with sonography in trauma (FAST), focused cardiac ultrasound (FOCUS), focused ultrasound and echocardiography (FUSE), focused assessment with transthoracic echocardiography (FATE), and focused echocardiography evaluation in life support (FEEL).

On an independent basis, advanced echocardiography allows detailed evaluation of the anatomy of the heart and of patient hemodynamics, using transthoracic echocardiography (TTE) and transesophageal echocardiography (TEE). Training in this area requires the necessary skills in ultrasound, Doppler-color and Doppler-tissue imaging, and the capacity to establish clinicopathological correlations with a view to adequately interpreting the more complex clinical conditions.

Two concepts have recently been developed that are of help in learning the application and usefulness of these techniques in the management of critical patients, specifically in the context of Intensive Care Medicine.

One of the concepts is so-called point-of-care ultrasonography, corresponding to real-time ultrasound used to obtain dynamic recordings that can be immediately correlated to the clinical condition of the patient and to the findings of the physical examination, and which moreover can be repeated in the event of any change in the patient condition or in the treatment provided.11 The characteristics of our medical specialty offer multiple applications for ultrasonography. Some of them are already well established, such as transcranial duplex ultrasound in neurocritical care, though the field of application has been extended to many other areas ranging from diagnostic or screening uses such as abdominal11 or pleuropulmonary ultrasound,12,13 to guidance in procedures such as central catheter placement,14,15 pericardial drainage, or the drainage of pleural collections. The modality with the greatest clinical application is the anatomical and functional study of the heart and major vessels using basic echocardiography techniques (Tables 2 and 3).

Based on the recommendations of Mayron et al.,16 protocols such as FUSE and FOCUS have been developed,17,18 defined as anatomical of physiological echocardiography aimed at answering a specific question and/or guiding a procedure, and performed by a competent physician with knowledge of the technique.

Without neglecting the contribution of other procedures, advanced echocardiography in the ICU aims to address several key issues in clinically unstable patients–assessing the underlying etiology, determining the hemodynamic profile and identifying the principal elements causing instability, with the selection of adequate initial treatment, and evaluation of the degree of response to the decision made.

Acquiring the necessary skills requires mastery of the morphological and functional analysis of the transthoracic exploration (TTE), including Doppler ultrasound. Such skills must be summed to knowledge of the possible cardiac functional repercussions of extrinsic factors including mechanical ventilation, inotropic drug support, extrarenal filtration techniques, etc. (Tables 4 and 5).

One of the main inconveniences of echocardiography in the ICU is the difficulty of securing an adequate acoustic window (due to interference by invasive and noninvasive mechanical ventilation, mobilization difficulties, bandages and thoracic drain devices, etc.), as well as its dependence upon operator experience. TEE largely resolves the difficulties of securing an adequate acoustic window. This is a semi-invasive technique in which the proximity of the esophagus to the cardiac structures allows the use of high-frequency probes affording high resolution, and offers a window in which images of the heart and major vessels can be obtained with a great increase in resolution with respect to TTE (Table 6). Likewise, TEE allows us to visualize areas of the heart that are not accessible to conventional ultrasound. The explorations made yield a high percentage of adequate images in critical patients, and the usefulness of the technique justifies the need for intensivists to acquire skills in the use of TEE.38

To date, few countries have developed specific training programs in critical patients. However, recently a full list has been published of the ultrasound skills required of intensivists, embodied in a “Declaration of Competencies” developed by two critical care societies.39 These skills or competencies encompass abdominal, thoracic and vascular ultrasound (General Critical Care Ultrasound), as well as echocardiography in critical care (Critical Care Echocardiography).

Likewise, the objective of the European CoBaTrICE (Competency-Based Training in Intensive Care) project, headed by the European Society of Intensive Care Medicine, with the participation of the SEMICYUC, is to develop an internationally accepted training program based on the development of competencies and with the principal purpose of harmonizing training.40

In Domain 2 (diagnosis, evaluation, investigation, monitorization and data interpretation), the CoBaTrICE describes the knowledge and indications for performing TTE and TEE as assessment, monitorization and investigation tools in the critical patient.

The competencies of intensivists in ultrasound are considered to include not only knowledge of the indications of echocardiography in the critical patient, but also the ability to perform and interpret echocardiographic studies,41,42 and consensus has been established regarding the training needed to reach different levels or grades of competency.43

Training in ultrasound should be protocolized and supervised according to the guidelines of the training programs referred to each of the specialties, and concordant with the European setting. In this context it is reasonable to follow the recommendations established on occasion of the congress of the European Society of Intensive Care Medicine in Vienna, in 2009, within the setting of a meeting held among different national associations (International Expert Statement on Training Standards for Critical Care Ultrasonography).44

A structured certification program is probably the best approach for standardizing professionals with the required skills and knowledge. Although from a medical-legal aspect competence is more relevant than certification, the latter is of great help in establishing a minimum and correct standard of practice.

The SEMICYUC should be committed to diffusing this document, establishing relations with other scientific societies, and affording legal coverage through accreditation of the training units, courses, and levels of competency.

It is the hope of the authors for the document to have national as well as international projection (through American societies which have the SEMICYUC as reference), and to position the SEMICYUC for subsequent agreements with the work groups other societies such as the Spanish Society of Cardiology, the Spanish Society of Internal Medicine (SEMI), the Spanish society of Anesthesia, Resuscitation and Pain Management, and the Spanish Society of Emergency Care Medicine.

An expanded version is available on the SEMICYUC website.

The authors declare that they have no conflicts of interest.