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Evaluation of and initial approach to the adult patient with undifferentiated hypotension and shock

David F Gaieski, MD
Mark E Mikkelsen, MD, MSCE
Section Editors
Polly E Parsons, MD
Robert S Hockberger, MD, FACEP
Deputy Editor
Geraldine Finlay, MD


Shock is a life-threatening condition of circulatory failure that most commonly presents with hypotension. It can also be heralded by other vital sign changes or the presence of elevated serum lactate levels. The effects of shock are initially reversible but can rapidly become irreversible, resulting in multi-organ failure (MOF) and death. Thus, when a patient presents with undifferentiated hypotension and/or is suspected of having shock, it is important that the clinician rapidly identify the etiology so that appropriate therapy can be administered to prevent MOF and death [1,2].

This topic reviews the clinical presentation as well as the initial diagnostic and therapeutic approaches to the adult patient with hypotension and suspected shock of unknown etiology (ie, undifferentiated shock). The definition, classification, etiology, and pathophysiology of shock are discussed separately. (See "Definition, classification, etiology, and pathophysiology of shock in adults".)


Shock is defined as a state of cellular and tissue hypoxia due to reduced oxygen delivery and/or increased oxygen consumption or inadequate oxygen utilization. This most commonly occurs when there is circulatory failure manifest as hypotension (ie, reduced tissue perfusion). “Undifferentiated shock” refers to the situation where shock is recognized, but the cause is unclear.

While patients often have a combination of more than one form of shock (multifactorial shock), four classes of shock are recognized (table 1):

Distributive (eg, septic shock, systemic inflammatory response syndrome, neurogenic shock, anaphylactic shock, toxic shock, end-stage liver disease, endocrine shock)

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Literature review current through: Nov 2017. | This topic last updated: Aug 01, 2017.
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  1. Vincent JL, De Backer D. Circulatory shock. N Engl J Med 2013; 369:1726.
  2. Rodgers KG. Cardiovascular shock. Emerg Med Clin North Am 1995; 13:793.
  3. Churpek MM, Zadravecz FJ, Winslow C, et al. Incidence and Prognostic Value of the Systemic Inflammatory Response Syndrome and Organ Dysfunctions in Ward Patients. Am J Respir Crit Care Med 2015; 192:958.
  4. Seymour CW, Liu VX, Iwashyna TJ, et al. Assessment of Clinical Criteria for Sepsis: For the Third International Consensus Definitions for Sepsis and Septic Shock (Sepsis-3). JAMA 2016; 315:762.
  5. Kraut JA, Madias NE. Lactic acidosis. N Engl J Med 2014; 371:2309.
  6. Liu VX, Morehouse JW, Marelich GP, et al. Multicenter Implementation of a Treatment Bundle for Patients with Sepsis and Intermediate Lactate Values. Am J Respir Crit Care Med 2016; 193:1264.
  7. Cardenas-Garcia J, Schaub KF, Belchikov YG, et al. Safety of peripheral intravenous administration of vasoactive medication. J Hosp Med 2015; 10:581.
  8. Walkey AJ, Wiener RS, Ghobrial JM, et al. Incident stroke and mortality associated with new-onset atrial fibrillation in patients hospitalized with severe sepsis. JAMA 2011; 306:2248.
  9. Levraut J, Ciebiera JP, Chave S, et al. Mild hyperlactatemia in stable septic patients is due to impaired lactate clearance rather than overproduction. Am J Respir Crit Care Med 1998; 157:1021.
  10. del Portal DA, Shofer F, Mikkelsen ME, et al. Emergency department lactate is associated with mortality in older adults admitted with and without infections. Acad Emerg Med 2010; 17:260.
  11. Cavallazzi R, Bennin CL, Hirani A, et al. Is the band count useful in the diagnosis of infection? An accuracy study in critically ill patients. J Intensive Care Med 2010; 25:353.
  12. Perera P, Mailhot T, Riley D, Mandavia D. The RUSH exam: Rapid Ultrasound in SHock in the evaluation of the critically lll. Emerg Med Clin North Am 2010; 28:29.
  13. Labovitz AJ, Noble VE, Bierig M, et al. Focused cardiac ultrasound in the emergent setting: a consensus statement of the American Society of Echocardiography and American College of Emergency Physicians. J Am Soc Echocardiogr 2010; 23:1225.
  14. Atkinson PR, McAuley DJ, Kendall RJ, et al. Abdominal and Cardiac Evaluation with Sonography in Shock (ACES): an approach by emergency physicians for the use of ultrasound in patients with undifferentiated hypotension. Emerg Med J 2009; 26:87.
  15. Shokoohi H, Boniface KS, Pourmand A, et al. Bedside Ultrasound Reduces Diagnostic Uncertainty and Guides Resuscitation in Patients With Undifferentiated Hypotension. Crit Care Med 2015; 43:2562.
  16. Ettin D, Cook T. Using ultrasound to determine external pacer capture. J Emerg Med 1999; 17:1007.
  17. Macedo W Jr, Sturmann K, Kim JM, Kang J. Ultrasonographic guidance of transvenous pacemaker insertion in the emergency department: a report of three cases. J Emerg Med 1999; 17:491.
  18. Soldati G, Testa A, Sher S, et al. Occult traumatic pneumothorax: diagnostic accuracy of lung ultrasonography in the emergency department. Chest 2008; 133:204.
  19. Zhang M, Liu ZH, Yang JX, et al. Rapid detection of pneumothorax by ultrasonography in patients with multiple trauma. Crit Care 2006; 10:R112.
  20. Knudtson JL, Dort JM, Helmer SD, Smith RS. Surgeon-performed ultrasound for pneumothorax in the trauma suite. J Trauma 2004; 56:527.
  21. Sartori S, Tombesi P, Trevisani L, et al. Accuracy of transthoracic sonography in detection of pneumothorax after sonographically guided lung biopsy: prospective comparison with chest radiography. AJR Am J Roentgenol 2007; 188:37.
  22. Rozycki GS, Feliciano DV, Ochsner MG, et al. The role of ultrasound in patients with possible penetrating cardiac wounds: a prospective multicenter study. J Trauma 1999; 46:543.
  23. Mandavia DP, Hoffner RJ, Mahaney K, Henderson SO. Bedside echocardiography by emergency physicians. Ann Emerg Med 2001; 38:377.
  24. Tayal VS, Kline JA. Emergency echocardiography to detect pericardial effusion in patients in PEA and near-PEA states. Resuscitation 2003; 59:315.
  25. Kanji HD, McCallum J, Sirounis D, et al. Limited echocardiography-guided therapy in subacute shock is associated with change in management and improved outcomes. J Crit Care 2014; 29:700.
  26. Volpicelli G, Lamorte A, Tullio M, et al. Point-of-care multiorgan ultrasonography for the evaluation of undifferentiated hypotension in the emergency department. Intensive Care Med 2013; 39:1290.
  27. Jones AE, Craddock PA, Tayal VS, Kline JA. Diagnostic accuracy of left ventricular function for identifying sepsis among emergency department patients with nontraumatic symptomatic undifferentiated hypotension. Shock 2005; 24:513.
  28. Taylor RA, Moore CL. Accuracy of emergency physician-performed limited echocardiography for right ventricular strain. Am J Emerg Med 2014; 32:371.
  29. Jones AE, Tayal VS, Sullivan DM, Kline JA. Randomized, controlled trial of immediate versus delayed goal-directed ultrasound to identify the cause of nontraumatic hypotension in emergency department patients. Crit Care Med 2004; 32:1703.
  30. Derr C, Drake JM. Esophageal rupture diagnosed with bedside ultrasound. Am J Emerg Med 2012; 30:2093.e1.
  31. Moore CL, Rose GA, Tayal VS, et al. Determination of left ventricular function by emergency physician echocardiography of hypotensive patients. Acad Emerg Med 2002; 9:186.
  32. Sabia P, Abbott RD, Afrookteh A, et al. Importance of two-dimensional echocardiographic assessment of left ventricular systolic function in patients presenting to the emergency room with cardiac-related symptoms. Circulation 1991; 84:1615.
  33. Haydar SA, Moore ET, Higgins GL 3rd, et al. Effect of bedside ultrasonography on the certainty of physician clinical decisionmaking for septic patients in the emergency department. Ann Emerg Med 2012; 60:346.
  34. Connors AF Jr, Speroff T, Dawson NV, et al. The effectiveness of right heart catheterization in the initial care of critically ill patients. SUPPORT Investigators. JAMA 1996; 276:889.
  35. Harvey S, Harrison DA, Singer M, et al. Assessment of the clinical effectiveness of pulmonary artery catheters in management of patients in intensive care (PAC-Man): a randomised controlled trial. Lancet 2005; 366:472.
  36. Shah MR, Hasselblad V, Stevenson LW, et al. Impact of the pulmonary artery catheter in critically ill patients: meta-analysis of randomized clinical trials. JAMA 2005; 294:1664.
  37. Mimoz O, Rauss A, Rekik N, et al. Pulmonary artery catheterization in critically ill patients: a prospective analysis of outcome changes associated with catheter-prompted changes in therapy. Crit Care Med 1994; 22:573.
  38. Hylands M, Moller MH, Asfar P, et al. A systematic review of vasopressor blood pressure targets in critically ill adults with hypotension. Can J Anaesth 2017; 64:703.
  39. Gamper G, Havel C, Arrich J, et al. Vasopressors for hypotensive shock. Cochrane Database Syst Rev 2016; 2:CD003709.
  40. Asfar P, Meziani F, Hamel JF, et al. High versus low blood-pressure target in patients with septic shock. N Engl J Med 2014; 370:1583.
  41. Pope JV, Jones AE, Gaieski DF, et al. Multicenter study of central venous oxygen saturation (ScvO(2)) as a predictor of mortality in patients with sepsis. Ann Emerg Med 2010; 55:40.
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