SHOCK INDEX AS A PREDICTOR OF HYPERLACTATEMIA FOR EARLY DETECTION OF SEVERE SEPSIS IN PATIENTS PRESENTING TO EMERGENCY DEPARTMENT OF A LOW TO MIDDLE INCOME COUNTRY
AbstractIntroduction: The epidemiology of Systemic Inflammatory Response Syndrome (SIRS) has been poorly understood accounts 17.8% annually 16.6 million adult per year. An agreement between Shock Index and Serum Lactate levels to reported to be 83%. With limited health resources in a low to middle income country, the need of markers that are non-invasive, cost effective. Shock index can serve this purpose as a surrogate marker of disease severity in patients with severe sepsis and thus resulting in early detection.Methods:This cross-sectional study was conducted from December 2014 to May 2015 at a tertiary care setup (Aga Khan University Hospital) in Karachi consisting of all septic patient received at the emergency department. Non-probability sampling technique was used. P-value <0.05 was taken as significant.Results:Out of 180 study participants 94 (52.22%) were males while 86 (47.78%) were females. The mean age was 57.48 ± 18.8 years. Shock index with cut off value of > 0.7 was used and moderate to strong agreement between the two was found with kappa κ = 0.786 (p = .000). Sensitivity was found to be 0.99, specificity 0.75, NPV 0.98, PPV 0.87. Conclusion:Shock index has very favorable features, availability, direct relevance to sepsis. A high SI predicts elevated lactate levels in patients with sepsis.Background: Early detection of sepsis in emergency department is of prime importance and require tools that are time and cost- effective. The Systemic Inflammatory Response Syndrome (SIRS) has been poorly associated with sepsis. Timothy et al in a retrospective analysis of Emergency Department (ED) visits stated estimate of SIRS at 17.8% accounting to an annual yield of 16.6 million adult visits with SIRS per year, among these only 26% accounted as an infectious aetiology of SIRS, trauma being 10% and other causes being rare. Shock index is found to be independently associated with 30-day mortality in a broad population of ED patients including sepsis. With limited health resources in a low to middle income country, focused utilization is important and so is the need of markers that are non-invasive, readily available, cost effective and easy to interpret. Shock index can serve this purpose as a surrogate marker of disease severity in patients with severe sepsis and thus resulting in early detection of such patients. Methods: This cross-sectional study was conducted from December 2014 to May 2015 at a tertiary care setup (Aga Khan University Hospital) in Karachi consisting of all septic patient received at the emergency department. Non-probability sampling technique was used. p-value <0.05 was taken as significant. Results: Out of 180 study participants 94 (52.22%) were males while 86 (47.78%) were females. The mean age was 57.48±18.8 years. Cohen's κ was used to determine an agreement between Shock index and Lactate levels. Shock index with cut off value of > 0.7 was used and moderate to strong agreement between the two was found with kappa κ = 0.786 which was statistically significant (p=<0.001). Sensitivity was found to be 0.99, specificity 0.75, NPV 0.98, PPV 0.87. Conclusion: To conclude shock index has some very favourable features, including availability, low cost and direct relevance to sepsis in terms of its high validity. A high SI predicts elevated lactate levels in patients with sepsis.Keywords: Sepsis; severe sepsis; septic shock; lactate levels; shock index
Horeczko T, Green JP, Panacek EA. Epidemiology of the systemic inflammatory response syndrome (SIRS) in the emergency department. West J Emerg Med 2014;15(3):329–36.
Tintinalli J. Tintinallis emergency medicine A comprehensive study guide: McGraw-Hill Education; 2015.
Levy MM, Dellinger RP, Townsend SR, Linde-Zwirble WT, Marshall JC, Bion J, et al. The Surviving Sepsis Campaign: results of an international guideline-based performance improvement program targeting severe sepsis. Intensive Care Med 2010;36(2):222–31.
Angus DC, Linde-Zwirble WT, Lidicker J, Clermont G, Carcillo J, Pinsky MR. Epidemiology of severe sepsis in the United States: analysis of incidence, outcome, and associated costs of care. Crit Care Med 2001;29(7):1303–10.
Rivers E, Nguyen B, Havstad S, Ressler J, Muzzin A, Knoblich B, et al. Early goal-directed therapy in the treatment of severe sepsis and septic shock. N Engl J Med 2001;345(19):1368–77.
Rajapakse S. Handbook of Critical Care Medicine. Ist ed. University of Colombo Sri Lanka; 2009.
Berger T, Green J, Horeczko T, Hagar Y, Garg N, Suarez A, et al. Shock index and early recognition of sepsis in the emergency department: pilot study. West J Emerg Med 2013;14(2):168.
Rady MY, Smithline HA, Blake H, Nowak R, Rivers E. A comparison of the shock index and conventional vital signs to identify acute, critical illness in the emergency department. Ann Emerg Med 1994;24(4):685–90.
Asaari H. Value of shock index in prognosticating the short-term outcome of death for patients presenting with severe sepsis and septic shock in the emergency department. Med J Malaysia 2012;67(4):407.
Kaukonen KM, Bailey M, Suzuki S, Pilcher D, Bellomo R. Mortality related to severe sepsis and septic shock among critically ill patients in Australia and New Zealand, 2000-2012. JAMA 2014;311(13):1308–16.
Marty P, Roquilly A, Vallée F, Luzi A, Ferré F, Fourcade O, et al. Lactate clearance for death prediction in severe sepsis or septic shock patients during the first 24 hours in Intensive Care Unit: an observational study. Ann Intensive Care 2013;3(1):3.
Gilboy N, Tanabe T, Travers D, Rosenau AM. Emergency Severity Index (ESI): A triage tool for emergency department. Rockville, MD: Agency Healthc Research and Quality: 2011.
Parikh R, Mathai A, Parikh S, Sekhar GC, Thomas R. Understanding and using sensitivity, specificity and predictive values. Indian J Ophthalmol 2008;56(1):45.
Kristensen AK, Holler JG, Hallas J, Lassen A, Shapiro NI. Is shock index a valid predictor of mortality in emergency department patients with hypertension, diabetes, high age, or receipt of β-or calcium channel blockers? Ann Emerg Med 2016;67(1):106–13.
Haas H. Outils de triage aux urgences pédiatriques. Arch Pédiatr 2005;12(6):703–5.
Raith EP, Udy AA, Bailey M, McGloughlin S, MacIsaac C, Bellomo R, et al. Prognostic accuracy of the SOFA score, SIRS criteria, and qSOFA score for in-hospital mortality among adults with suspected infection admitted to the intensive care unit. JAMA 2017;317(3):290–300.
Wira CR, Francis MW, Bhat S, Ehrman R, Conner D, Siegel M. The shock index as a predictor of vasopressor use in emergency department patients with severe sepsis. West J Emerg Med 2014;15(1):60–6.
Strehlow MC, Emond SD, Shapiro NI, Pelletier AJ, Camargo Jr CA. National study of emergency department visits for sepsis, 1992 to 2001. Ann Emerg Med 2006;48(3):326–31.e1–3.
Osborn TM, Nguyen HB, Rivers EP. Emergency medicine and the surviving sepsis campaign: an international approach to managing severe sepsis and septic shock. Ann Emerg Med 2005;46(3):228–31