Diagnostic accuracy of the RUSH protocol in identifying the cause of shock: a prospective study from an Indian emergency department
DOI:
https://doi.org/10.18203/2320-6012.ijrms20260236Keywords:
Diagnostic accuracy, Emergency medicine, PoCUS, Point-of-care ultrasound, RUSH protocol, ShockAbstract
Background: Shock is a life-threatening emergency characterized by inadequate tissue perfusion, requiring rapid identification of the underlying etiology to guide targeted management. Early clinical assessment may be unreliable because of overlapping presentations. The Rapid Ultrasound in Shock and Hypotension (RUSH) protocol provides a structured point-of-care ultrasonography (PoCUS) approach to differentiate shock subtypes at the bedside.
To evaluate the diagnostic accuracy of the RUSH protocol in identifying the etiology of non-traumatic undifferentiated shock in an Indian emergency department and to assess its agreement with the final confirmed clinical diagnosis.
Methods: This prospective observational study included 100 adult patients presenting with shock to a tertiary emergency department. All patients underwent a standardized RUSH examination performed by trained emergency physicians. Ultrasound-based provisional diagnoses were compared with final diagnoses established using comprehensive clinical evaluation, imaging and laboratory investigations. Diagnostic performance was assessed using sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and Cohen’s kappa coefficient.
Results: The mean patient age was 44.97±10.88 years, with a male predominance (69%). Distributive shock was the most common etiology (39%). The RUSH protocol showed the highest diagnostic accuracy for obstructive shock (sensitivity, specificity, PPV and NPV all 100%, κ=1.0). Good agreement was observed for cardiogenic (κ = 0.93), hypovolemic (κ=0.87) and distributive shock (κ=0.87), while overlap was greatest in hypovolemic/distributive shock (κ=0.76).
Conclusions: The RUSH protocol is a rapid, reliable bedside tool for early etiological diagnosis of shock and supports timely, goal-directed resuscitation in emergency settings.
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References
Janssens U, Graf J. Shock: What are the basics. Internist (Berl). 2004;45(3):258–66. DOI: https://doi.org/10.1007/s00108-003-1135-x
Perera P, Mailhot T, Riley D. The RUSH exam: Rapid ultrasound in shock in the evaluation of the critically ill. Emerg Med Clin North Am. 2010;28(1):29–56. DOI: https://doi.org/10.1016/j.emc.2009.09.010
Perera P, Mailhot T, Riley D, Mandavia D. The RUSH exam: Rapid ultrasound in shock in the evaluation of the critically ill patient. Ultrasound Clin. 2012;7(2):255–78. DOI: https://doi.org/10.1016/j.cult.2011.12.010
Liteplo A, Noble V, Atkinson P. My patient has no blood pressure: Point-of-care ultrasound in the hypotensive patient—FAST and reliable. Ultrasound. 2012;20(1):64–8. DOI: https://doi.org/10.1258/ult.2011.011044
Strehlow MC. Early identification of shock in critically ill patients. Emerg Med Clin North Am. 2010;28(1):57–66. DOI: https://doi.org/10.1016/j.emc.2009.09.006
Blaivas M. Incidence of pericardial effusion in patients presenting to the emergency department with unexplained dyspnea. Acad Emerg Med. 2001;8(12):1143–6. DOI: https://doi.org/10.1111/j.1553-2712.2001.tb01130.x
Shabetai R. Pericardial effusion: Haemodynamic spectrum. Heart. 2004;90(3):255–6. DOI: https://doi.org/10.1136/hrt.2003.024810
Spodick DH. Acute cardiac tamponade. N Engl J Med. 2003;349(7):684–90. DOI: https://doi.org/10.1056/NEJMra022643
Nabavizadeh SA, Meshksar A. Ultrasonographic diagnosis of cardiac tamponade in trauma patients using collapsibility index of inferior vena cava. Acad Radiol. 2007;14(4):505–6. DOI: https://doi.org/10.1016/j.acra.2007.01.014
Ahmadpour H, Shah AA, Allen JW. Mitral E-point septal separation: A reliable index of left ventricular performance in coronary artery disease. Am Heart J. 1983;106(1):21–8. DOI: https://doi.org/10.1016/0002-8703(83)90433-7
Silverstein JR, Laffely NH, Rifkin RD. Quantitative estimation of left ventricular ejection fraction from mitral valve E-point to septal separation and comparison to magnetic resonance imaging. Am J Cardiol. 2006;97(1):137–40. DOI: https://doi.org/10.1016/j.amjcard.2005.07.118
Secko MA, Lazar JM, Salciccioli L, Stone MB. Can junior emergency physicians use E-point septal separation to accurately estimate left ventricular function in acutely dyspneic patients. Acad Emerg Med. 2011;18(11):1223–6. DOI: https://doi.org/10.1111/j.1553-2712.2011.01196.x
Vieillard-Baron A, Page B, Augarde R. Acute cor pulmonale in massive pulmonary embolism: Incidence, echocardiographic pattern, clinical implications and recovery rate. Intensive Care Med. 2001;27(9):1481–6. DOI: https://doi.org/10.1007/s001340101032
Mookadam F, Jiamsripong P, Goel R, Warsame TA, Emani UR, Khandheria BK. Critical appraisal on the utility of echocardiography in the management of acute pulmonary embolism. Cardiol Rev. 2010;18(1):29–37. DOI: https://doi.org/10.1097/CRD.0b013e3181c09443
Grifoni S, Olivotto I, Cecchini P. Utility of an integrated clinical, echocardiographic and venous ultrasonographic approach for triage of patients with suspected pulmonary embolism. Am J Cardiol. 1998;82(10):1230–5. DOI: https://doi.org/10.1016/S0002-9149(98)00612-2
Jardin F, Dubourg O, Gueret P, Delorme G, Bourdarias JP. Quantitative two-dimensional echocardiography in massive pulmonary embolism: Emphasis on ventricular interdependence and leftward septal displacement. J Am Coll Cardiol. 1987;10(6):1201–6. DOI: https://doi.org/10.1016/S0735-1097(87)80119-5
Randazzo MR, Snoey ER, Levitt MA, Binder K. Accuracy of emergency physician assessment of left ventricular ejection fraction and central venous pressure using echocardiography. Acad Emerg Med. 2003;10(9):973–7. DOI: https://doi.org/10.1197/S1069-6563(03)00317-8
Jardin F, Vieillard-Baron A. Ultrasonographic examination of the venae cavae. Intensive Care Med. 2006;32(2):203–6. DOI: https://doi.org/10.1007/s00134-005-0013-5
Marik PA. Techniques for assessment of intravascular volume in critically ill patients. J Intensive Care Med. 2009;24(5):329–37. DOI: https://doi.org/10.1177/0885066609340640
Blehar DJ, Dickman E, Gaspari R. Identification of congestive heart failure via respiratory variation of inferior vena cava diameter. Am J Emerg Med. 2009;27(1):71–5. DOI: https://doi.org/10.1016/j.ajem.2008.01.002
Nagdev AD, Merchant RC, Tirado-Gonzalez A, Sisson CA, Murphy MC. Emergency department bedside ultrasonographic measurement of the caval index for noninvasive determination of low central venous pressure. Ann Emerg Med. 2010;55(3):290–5. DOI: https://doi.org/10.1016/j.annemergmed.2009.04.021
Schefold JC, Storm C, Bercker S. Inferior vena cava diameter correlates with invasive hemodynamic measures in mechanically ventilated intensive care unit patients with sepsis. J Emerg Med. 2010;38(5):632–7. DOI: https://doi.org/10.1016/j.jemermed.2007.11.027