Study tests ultrasound-guided leg raise for fluid response in pigs
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A new Journal of Veterinary Emergency and Critical Care study suggests a modified passive leg-raising maneuver, paired with transthoracic ultrasound, may help identify which anesthetized pigs are likely to respond to fluids without giving a test bolus first. In the prospective laboratory study, Lisa Tarragona and colleagues evaluated healthy, mechanically ventilated pigs under sevoflurane anesthesia and found that an increase in aortic velocity-time integral measured by transthoracic echocardiography could predict fluid responsiveness, with a reported cutoff of at least 11.2%. The paper was published on February 10, 2026, and builds on earlier swine work showing that a modified passive leg-raising maneuver can transiently increase cardiac output in hypovolemic, anesthetized pigs. (deepdyve.com)
Why it matters: For veterinary professionals, the appeal is straightforward: fluid assessment during anesthesia and critical care is still a balancing act, and unnecessary fluid loading can be harmful. A noninvasive, reversible bedside maneuver that uses transthoracic echocardiography rather than a fluid challenge could support more targeted decision-making, especially in settings already using point-of-care ultrasound. At the same time, this was an experimental study in healthy pigs under controlled anesthetic conditions, so the findings shouldn’t be treated as immediately interchangeable with clinical patients, spontaneous breathers, or other species without further validation. Human critical care literature has long supported passive leg raising plus echocardiographic stroke volume surrogates as a useful dynamic test, but operator skill and case selection remain important limitations. (researchgate.net)
What to watch: The next step is whether this ultrasound-guided approach can be validated in clinically ill veterinary patients, and then translated beyond research pigs into everyday anesthesia and emergency practice. (pubmed.ncbi.nlm.nih.gov)