OVERVIEW
The diagnostic ultrasound was pioneered at around 1950, but at that time the equipment was bulky, nonmovable, and complicated. With advancement of technology and newer innovations, the once large, unwieldy machine had become compact, miniaturized, and more portable and hence really available at the bedside.
This accessibility to bedside ultrasound machine has given rise to the concept of point-of-care ultrasound (POCUS), which means bringing the technology at the bedside of the patient and being performed by the treating clinician to gain information about the deranged physiology and pathology of the patient and applying this information in planning the management of the patient, the critical care armamentarium has revolutionized. In nutshell, it is goal directed examination aimed at providing rapid, reliable, and real time insight into what is going on in a patient.
Point-of-care ultrasound is not designed to replace the traditional patient examination but it is an added information along with detailed history, physical examination, and forming a provisional diagnosis. The idea is to decrease the lag time in decision-making and to formulate a treating diagnosis. Most of the questions that need to be answered has bimodal answers, either yes or no. This helps in ruling out the differential diagnosis and targeting the most probable cause of derangement in the patient. The modern day ultrasound machines have become very compact, cheap, increased mobility, and equipped with latest technologies to give the desired information.
Why Point-of-Care Ultrasound?
Traditionally, the ultrasound done by either the radiologist or the technician is very detailed but the correlation with the patient condition is generally missing and has no real-time connection with the management of such patients. Similarly, the cardiologist is very busy and for him to perform an echocardiogram just to inform the cardiac function is never a big priority. But as a bedside clinician, you require rapid and reliable answers as they would help you in formulating the plan of management of a sick patient. POCUS allows a clinician to take rapid decisions which result in timely intervention on these patients and possibly change the outcome.1 As per Manno et al.2 it has been shown that just by doing POCUS of all patients admitted to the intensive care unit (ICU), changes the diagnosis in 26% of patients and prompted invasive procedures in almost 18% of the patients. They named this the “ICU-sound” protocol.4
APPLICATIONS
Point-of-care ultrasound can be applied to any body part and for assessment of any disease. In critical care and emergency department, the questions that need to answered are of urgent nature. One should always be aware of the limitations of ultrasonography (USG) when certain patient factors like morbid obesity, subcutaneous emphysema, or large dressings at the site of examination preclude the use of USG. Still POCUS has great applicability and in the ICU, these can be divided into three broad categories:
- Diagnostic:
- Airway patency and signs of deviation
- Prediction of intubation difficulty
- Assessment of prandial status
- Diagnosis of lung conditions like consolidation, atelectasis, pleural effusion, acute respiratory distress syndrome (ARDS), pneumothorax
- Cardiac conditions like pulmonary embolism, pulmonary edema, pericardial effusion, and tamponade
- Deep vein thrombosis (DVT)
- Intraperitoneal collections.
- Therapeutic:
- Gaining vascular access
- Drainages of collections like pleural effusion, pericardial effusion, intra-abdominal collection
- Cricothyroidotomy and percutaneous tracheostomy
- Position of temporary pacemaker leads.
- Assessment:
- Fluid status assessment
- Lung aeration and deaeration assessment
- Resolution of pneumothorax after decompression
- Improvement in pulmonary edema, interval progression, or regression of consolidation.
THE EVIDENCE
Due to increased use of POCUS by clinicians in various fields of medicine, the professional societies like American Institute of Ultrasound in Medicine (AIUM), American College of Emergency Physicians (ACEP), American College of Chest Physicians (ACCP), and American Society of Echocardiography (ASE) have published guidelines about the use of POCUS in critical areas like emergency wards and ICUs. Similarly, the European Society of Intensive Care Medicine (ESICM) has also published their practice recommendations on lung ultrasound. The inclusion of ultrasound as focused assessment by sonography in trauma (FAST) scan in trauma has long been practiced with excellent sensitivity and specificity.3
THE PURPOSE
The purpose of this core curriculum about POCUS in critical care is to train healthcare professionals to safely use ultrasound in their clinical practice and also to get themselves5 certified for the same. You would be going through the entire head-to-toe examination with the help of ultrasound and will also come across practice recommendations which we propagate. After the completion of this curriculum, one should be able to perform POCUS in routine clinical practice with good proficiency and help in patient management.
The idea of this curriculum is to train the physicians in the use of POCUS as per the latest recommendations, then provide them credentialing for safe use in their clinical practice, and motivate them to constantly re-appraise their clinical skill.
REFERENCES
- Kory PD, Pellecchia CM, Shiloh AL, Mayo PH, DiBello C, Koenig S. Accuracy of ultrasonography performed by critical care physicians for the diagnosis of DVT. Chest. 2011;139:538–54.
- Manno E, Navarra M, Faccio L, Motevallian M, Bertolaccini L, Mfochivè A, et al. Deep impact of ultrasound in the intensive care unit: the “ICU-sound” protocol. Anesthesiology. 2012;117(4):801–9.