Summary Listen
- The speaker, an intensivist, shares over 25 years of experience with Point-of-Care Ultrasound (POCUS) in intensive care, starting when it was uncommon. He initiated his echo training in Kolkata and continued in Delhi, routinely using ultrasound to assess patients' hemodynamic status, noting its evolution into a norm, with ongoing research including AI integration.
- POCUS offers rapid diagnosis, reducing hospital stays and costs, and can identify life-threatening conditions like acute MI or large liver abscesses. It's portable, non-invasive, and essential for intensivists. The physics involves piezoelectric transducers converting electricity to ultrasound waves and back, with resolution directly proportional to frequency and inversely proportional to depth.
- Key probes for ICU include linear (high frequency, superficial structures like neck veins, pleura, vascular access), curvilinear (lower frequency, deeper penetration for abdominal, e-FAST, large vessels, and general abdominal organs), and phased array (small footprint, deep penetration for cardiac and hemodynamic assessment, sometimes e-FAST).
- Cardiac ultrasound focuses on immediate identification of hemodynamic instability, assessing contractility, ejection fraction, and pericardial effusions. Standard views include parasternal long and short axis, apical four-chamber, and subcostal views (four-chamber and IVC). Structures like RV, LV, atria, valves (mitral, aortic, tricuspid), and outflow tracts are visualized.
- Hemodynamic assessment involves evaluating IVC diameter and collapsibility (for non-ventilated patients) or distensibility (for ventilated patients), calculating stroke volume using LVOT diameter and VTI, and assessing LV ejection fraction. Dynamic parameters like stroke volume variability and response to passive leg raise (PLR) are crucial for fluid responsiveness.
- VEXUS (Venous Excess Ultrasound Scan) assesses systemic venous congestion and fluid tolerance in critically ill patients, looking at IVC, hepatic, portal, and renal vein Doppler patterns. Although specialized, it provides detailed insight into fluid status, while IVC collapsibility and distensibility are more routinely used for fluid responsiveness.
- The RUSH (Rapid Ultrasound in Shock) protocol systematically examines the heart, IVC, abdomen (Morison's pouch), aorta, and lungs to quickly diagnose the cause of shock, identifying conditions like cardiac tamponade, RV dysfunction (MacConnell's sign for PE), LV dysfunction (cardiogenic shock), hypovolemic shock, and abdominal aortic aneurysm rupture.
- Lung ultrasound is performed by dividing the lungs into 12 sectors, using a linear probe. A-lines indicate air, while B-lines (comet tail artifacts) signify fluid in the alveoli, seen in pulmonary edema. Pneumonia is identified by a "hepatized lung" appearance (loss of eco-definition between lung and liver) and air bronchograms. Pleural effusions are seen as anechoic collections, sometimes with a "veldtail sign" (collapsed lung within effusion).
- Pneumothorax is diagnosed by the absence of "lung sliding" between parietal and visceral pleura. M-mode shows a "barcode sign" or "stratosphere sign" instead of the normal "seashore sign." A "lung point" where sliding reappears helps localize the pneumothorax. Protocols like BLUE and FALLS guide the diagnostic approach for dyspnea and shock.
- Other POCUS applications include Transcranial Doppler (TCD) for cerebral blood flow, Optic Nerve Sheath Diameter (ONSD) measurement (using a linear probe) to detect raised intracranial pressure (normal < 5.8mm), and diagnosing maxillary sinusitis by assessing fluid levels within the sinus.
- Clinical examples include Takotsubo cardiomyopathy (LV ballooning), cardiac tamponade with RV collapse, left atrial myxoma, large atrial septal defect, deep vein thrombosis (DVT), and central venous access guidance, highlighting the versatility of POCUS. Limitations include patient obesity, bowel gas interference, mechanical ventilation challenges, and inter-observer variability, emphasizing the need for skilled practice and adherence to regulatory guidelines.
Sample Certificate
About the Speakers
Dr. Leelavati Thakur
Senior Consultant Critical Care Medicine The Mission Hospital, West Bengal
Financial Disclosure
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