Seventeen studies evaluated the accuracy of physician's estimates or ‘educated guesses’ of CO as compared to objectively measured CO. Estimates were based on clinical examination, with or without knowledge of medical history, biochemical values and/or radiological imaging (Table 2). Some studies used a categorical variable for CO estimates (e.g. ‘low’, ‘normal’ or ‘high’), whereas others used a continuous scale (e.g. 1–12 l per min) [15,17,62▪▪]. Physician's estimates were correct in 42–62% of the time [13–18,52–61]. Moderate-to-reasonable correlations and a high percentage error were found when physician's estimates of continuous CO were compared to objectively measured CO[15,16,62▪▪]. Moderate-to-very poor agreements were found in studies that used weighted κ statistics to address agreement occurring by chance [55,59,60,67]. In addition, two studies reported that 21 and 26% of the CO estimations were completely disparate (an estimated high CO when the objective CO was low or vice versa) [55,59].
These results suggest that physicians are not very capable to subjectively estimate CO based on clinical examination. The widely varying diagnostic accuracies are probably the result of different populations or cutoffs for a low CO, but overall it seems that physician's estimates are ‘an inaccurate diagnostic test’. This is in accordance with two studies of Saugel et al.[67,68], which both demonstrate the incapability of physicians to reliably assess volume status using simple clinical signs. Furthermore, five out of six studies concluded that predictions of senior staff members were equally bad as those of residents or fellows [13,18,54,61,62▪▪,69]. Finally, one study found that the accuracy of estimates was unrelated to the level of confidence physicians had in their assessment .
Several important limitations apply. Many studies did not elaborate their methods of clinical examination in terms of variables used and definitions employed, leaving variability at the physician's discretion so that these studies cannot be reproduced. PAC was used in most studies, but only in selected patients who failed to respond to initial therapy or in whom clinical examination alone was deemed insufficient, so that evaluation of the accuracy of clinically estimated CO will be biased by definition. Likewise, many other studies also used convenience samples, which hampers generalizability of their results. Clinical examination should be performed in a standardized fashion, according to a protocol, to maximize interobserver agreement and generalizability.
Papers of particular interest, published within the annual period of review, have been highlighted as:
1. De Backer D, Biston P, Devriendt J, et al. Comparison of dopamine and norepinephrine in the treatment of shock
. N Engl J Med 2010; 362:779–789.
2. Vincent JL, Marshall JC, Namendys-Silva SA, et al. Assessment of the worldwide burden of critical illness
: the intensive care over nations (ICON) audit. Lancet Respir Med 2014; 2:380–386.
3. De Backer D, Donadello K, Sakr Y, et al. Microcirculatory alterations in patients with severe sepsis: impact of time of assessment and relationship with outcome. Crit Care Med 2013; 41:791–799.
4. Cecconi M, De Backer D, Antonelli M, et al. Consensus on circulatory shock
and hemodynamic monitoring. Task force of the European Society of Intensive Care Medicine. Intensive Care Med 2014; 40:1795–1815.
5. Postelnicu R, Evans L. Monitoring of the physical exam in sepsis. Curr Opin Crit Care 2017; 23:232–236.
6▪▪. Elder A, Japp A, Verghese A. How valuable is physical examination
of the cardiovascular system? BMJ 2016; 354:i3309.
This review extensively elaborates the diagnostic accuracy of physical examination of the cardiovascular system.
7▪. Bentzer P, Griesdale DE, Boyd J, et al. Will this hemodynamically unstable patient respond to a bolus of intravenous fluids? JAMA 2016; 316:1298–1309.
This review provides a comprehensive overview of studies that measure hypovolemia.
8. Billman GE. Heart rate variability: a historical perspective. Front Physiol 2011; 2:86.
9. Bedford DE. The ancient art of feeling the pulse. Br Heart J 1951; 13:423–437.
10. Ebert RV, Stead EA. Circulatory failure in acute infections. J Clin Invest 1941; 20:671–679.
11. Swan HJ, Ganz W, Forrester J, et al. Catheterization of the heart in man with use of a flow-directed balloon-tipped catheter. N Engl J Med 1970; 283:447–451.
12. Ganz W, Donoso R, Marcus HS, et al. A new technique for measurement of cardiac output
by thermodilution in man. Am J Cardiol 1971; 27:392–396.
13. Connors AF Jr, McCaffree DR, Gray BA. Evaluation of right-heart catheterization in the critically ill patient without acute myocardial infarction. N Engl J Med 1983; 308:263–267.
14. Eisenberg PR, Jaffe AS, Schuster DP. Clinical evaluation compared to pulmonary artery catheterization in the hemodynamic assessment of critically ill patients. Crit Care Med 1984; 12:549–553.
15. Tuchschmidt J, Sharma OP. Impact of hemodynamic monitoring in a medical intensive care unit. Crit Care Med 1987; 15:840–843.
16. Celoria G, Steingrub JS, Vickers-Lahti M, et al. Clinical assessment of hemodynamic values in two surgical intensive care units. Effects on therapy. Arch Surg 1990; 125:1036–1039.
17. Connors AF Jr, Dawson NV, Shaw PK, et al. Hemodynamic status in critically ill patients with and without acute heart disease. Chest 1990; 98:1200–1206.
18. 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; 22:573–579.
19. Robin ED. Death by pulmonary artery flow-directed catheter. Time for a moratorium? Chest 1987; 92:727–731.
20. 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; 294:1664–1670.
21. Marik PE. Obituary: pulmonary artery catheter 1970 to 2013. Ann Intensive Care 2013; 3:38–43.
22. Rajaram SS, Desai NK, Kalra A, et al. Pulmonary artery catheters for adult patients in intensive care. Cochrane Database Syst Rev 2013; 2:CD003408.
23. Vincent JL, Rhodes A, Perel A, et al. Clinical review: update on hemodynamic monitoring – a consensus of 16. Crit Care 2011; 15:229.
24. Alhashemi JA, Cecconi M, Hofer CK. Cardiac output
monitoring: an integrative perspective. Crit Care 2011; 15:214.
25. Schloglhofer T, Gilly H, Schima H. Semi-invasive measurement of cardiac output
based on pulse contour: a review and analysis. Can J Anaesth 2014; 61:452–479.
26. Teboul JL, Saugel B, Cecconi M, et al. Less invasive hemodynamic monitoring in critically ill patients. Intensive Care Med 2016; 42:1350–1359.
27. Sevransky J. Clinical assessment of hemodynamically unstable patients. Curr Opin Crit Care 2009; 15:234–238.
28. Sackett DL. The rational clinical examination
. A primer on the precision and accuracy of the clinical examination
. JAMA 1992; 267:2638–2644.
29. McGee S. Simplifying likelihood ratios. J Gen Intern Med 2002; 17:646–649.
30. Sackett D, Simel D. Keitz S. A primer on the precision and accuracy of the clinical examination
& an updated summary. The rational clinical examination
: evidence-based clinical diagnosis. New York: McGraw-Hill Professional Jama & Archives Journals; 2009. 1–16.
31. Kaplan LJ, McPartland K, Santora TA, Trooskin SZ. Start with a subjective assessment of skin temperature to identify hypoperfusion in intensive care unit patients. J Trauma 2001; 50:620–627. discussion 627-8.
32. Schey BM, Williams DY, Bucknall T. Skin temperature as a noninvasive marker of haemodynamic and perfusion status in adult cardiac surgical patients: an observational study. Intensive Crit Care Nurs 2009; 25:31–37.
33. Joly HR, Weil MH. Temperature of the great toe as an indication of the severity of shock
. Circulation 1969; 39:131–138.
34. Woods I, Wilkins RG, Edwards JD, et al. Danger of using core/peripheral temperature gradient as a guide to therapy in shock
. Crit Care Med 1987; 15:850–852.
35. Vincent JL, Moraine JJ, van der Linden P. Toe temperature versus transcutaneous oxygen tension monitoring during acute circulatory failure. Intensive Care Med 1988; 14:64–68.
36. Sommers MS, Stevenson JS, Hamlin RL, Ivey TD. Skin temperature and limb blood flow as predictors of cardiac index. Clin Nurs Res 1995; 4:22–37.
37. Boerma EC, Kuiper MA, Kingma WP, et al. Disparity between skin perfusion and sublingual microcirculatory alterations in severe sepsis and septic shock
: a prospective observational study. Intensive Care Med 2008; 34:1294–1298.
38. Bourcier S, Pichereau C, Boelle PY, et al. Toe-to-room temperature gradient correlates with tissue perfusion and predicts outcome in selected critically ill patients with severe infections. Ann Intensive Care 2016; 6:63–71.
39. Ait-Oufella H, Bige N, Boelle PY, et al. Capillary refill time exploration during septic shock
. Intensive Care Med 2014; 40:958–964.
40. Bailey JM, Levy JH, Kopel MA, et al. Relationship between clinical evaluation of peripheral perfusion and global hemodynamics in adults after cardiac surgery. Crit Care Med 1990; 18:1353–1356.
41. Ait-Oufella H, Lemoinne S, Boelle PY, et al. Mottling score predicts survival in septic shock
. Intensive Care Med 2011; 37:801–807.
42. Wo CC, Shoemaker WC, Appel PL, et al. Unreliability of blood pressure and heart rate to evaluate cardiac output
in emergency resuscitation and critical illness
. Crit Care Med 1993; 21:218–223.
43. Kuntscher MV, Germann G, Hartmann B. Correlations between cardiac output
, stroke volume, central venous pressure, intra-abdominal pressure and total circulating blood volume in resuscitation of major burns. Resuscitation 2006; 70:37–43.
44. Kholoussy AM, Sufian S, Pavlides C, Matsumoto T. Central peripheral temperature gradient. Its value and limitations in the management of critically ill surgical patients. Am J Surg 1980; 140:609–612.
45. Schey BM, Williams DY, Bucknall T. Skin temperature and core-peripheral temperature gradient as markers of hemodynamic status in critically ill patients: a review. Heart Lung 2010; 39:27–40.
46. Champion HR, Sacco WJ, Hannan DS, et al. Assessment of injury severity: the triage index. Crit Care Med 1980; 8:201–208.
47. van Genderen ME, Lima A, Akkerhuis M, et al. Persistent peripheral and microcirculatory perfusion alterations after out-of-hospital cardiac arrest are associated with poor survival. Crit Care Med 2012; 40:2287–2294.
48. Coudroy R, Jamet A, Frat JP, et al. Incidence and impact of skin mottling over the knee and its duration on outcome in critically ill patients. Intensive Care Med 2015; 41:452–459.
49. de Moura EB, Amorim FF, da Cruz Santana AN, et al. Skin mottling score as a predictor of 28-day mortality in patients with septic shock
. Intensive Care Med 2016; 42:479–480.
50. Lattik R, Couture P, Denault AY, et al. Mitral Doppler indices are superior to two-dimensional echocardiographic and hemodynamic variables in predicting responsiveness of cardiac output
to a rapid intravenous infusion of colloid. Anesth Analg 2002; 94:1092–1099. table of contents.
51. van Genderen ME, Bartels SA, Lima A, et al. Peripheral perfusion index as an early predictor for central hypovolemia in awake healthy volunteers. Anesth Analg 2013; 116:351–356.
52. Connors AF Jr, Dawson NV, McCaffree R, et al. Assessing hemodynamic status in critically ill patients: do physicians use clinical information optimally? J Crit Care 1987; 2:174–180.
53. Steingrub JS, Celoria G, Vickers-Lahti M, et al. Therapeutic impact of pulmonary artery catheterization in a medical/surgical ICU. Chest 1991; 99:1451–1455.
54. Staudinger T, Locker GJ, Laczika K, et al. Diagnostic validity of pulmonary artery catheterization for residents at an intensive care unit. J Trauma 1998; 44:902–906.
55. Rodriguez RM, Berumen KA. Cardiac output
measurement with an esophageal Doppler in critically ill emergency department patients. J Emerg Med 2000; 18:159–164.
56. Linton RA, Linton NW, Kelly F. Is clinical assessment of the circulation reliable in postoperative cardiac surgical patients? J Cardiothorac Vasc Anesth 2002; 16:4–7.
57. Iregui MG, Prentice D, Sherman G, et al. Physicians’ estimates of cardiac index and intravascular volume based on clinical assessment versus transesophageal Doppler measurements obtained by critical care nurses. Am J Crit Care 2003; 12:336–342.
58. Veale WN Jr, Morgan JH, Beatty JS, et al. Hemodynamic and pulmonary fluid status in the trauma patient: are we slipping? Am Surg 2005; 71:621–625. discussion 625-6.
59. Rodriguez RM, Lum-Lung M, Dixon K, Nothmann A. A prospective study on esophageal Doppler hemodynamic assessment in the ED. Am J Emerg Med 2006; 24:658–663.
60. Nowak RM, Sen A, Garcia AJ, et al. The inability of emergency physicians to adequately clinically estimate the underlying hemodynamic profiles of acutely ill patients. Am J Emerg Med 2012; 30:954–960.
61. Duan J, Cong LH, Wang H, et al. Clinical evaluation compared to the pulse indicator continuous cardiac output
system in the hemodynamic assessment of critically ill patients. Am J Emerg Med 2014; 32:629–633.
62▪▪. Perel A, Saugel B, Teboul JL, et al. The effects of advanced monitoring on hemodynamic management in critically ill patients: a pre and post questionnaire study. J Clin Monit Comput 2016; 30:511–518.
This large multicenter study included a broad ICU cohort and used sophisticated statistical measures to correlate CO to clinical examination.
63. Ramo BW, Myers N, Wallace AG, et al. Hemodynamic findings in 123 patients with acute myocardial infarction on admission. Circulation 1970; 42:567–577.
64. Forrester JS, Diamond GA, Swan HJ. Correlative classification of clinical and hemodynamic function after acute myocardial infarction. Am J Cardiol 1977; 39:137–145.
65. Grissom CK, Morris AH, Lanken PN, et al. Association of physical examination
with pulmonary artery catheter parameters in acute lung injury. Crit Care Med 2009; 37:2720–2726.
66. Sasse SA, Chen PA, Mahutte CK. Relationship of changes in cardiac output
to changes in heart rate in medical ICU patients. Intensive Care Med 1996; 22:409–414.
67. Saugel B, Ringmaier S, Holzapfel K, et al. Physical examination
, central venous pressure, and chest radiography for the prediction of transpulmonary thermodilution-derived hemodynamic parameters in critically ill patients: a prospective trial. J Crit Care 2011; 26:402–410.
68. Saugel B, Wagner JY, Wendon J, Perel A. Getting the full diagnostic picture in intensive care medicine: a plea for ‘physiological examination’. Ann Am Thorac Soc 2015; 12:1738–1739.
69. Dawson NV, Connors AF Jr, Speroff T, et al. Hemodynamic assessment in managing the critically ill: is physician confidence warranted? Med Decis Making 1993; 13:258–266.
70. Vazquez R, Gheorghe C, Kaufman D, Manthous CA. Accuracy of bedside physical examination
in distinguishing categories of shock
: a pilot study. J Hosp Med 2010; 5:471–474.
71. Sakr Y, Reinhart K, Vincent JL, et al. Does dopamine administration in shock
influence outcome? Results of the Sepsis Occurrence in Acutely Ill Patients (SOAP) Study. Crit Care Med 2006; 34:589–597.