COMMENTARY
The Prehospital Sepsis Screen: A Test in Search of an Application?
I
n this issue of Academic Emergency Medicine, Bayer and colleagues1 report on a study from Germany deriving a scoring system for the detection of sepsis in the prehospital setting. As one would expect, the authors started with the SIRS criteria, added other parameters commonly measured in the EMS setting, and used a multiple logistic regression model to derive the system. The area under the curve for the final model was a surprisingly good at 0.93 and remained at 0.93 using the simplified scoring system that the authors generated by transforming the regression weights into easily calculable numbers. It is worth noting that the EMS system that was involved in Bayer’s study is quite different from the EMS systems that most of our readers work with, in that all of the patients in the study were cared for by prehospital physicians (mainly anesthesiologists with intensive care experience). However, the parameters in the final model (heart rate, blood pressure, Glasgow Coma Scale score, respiratory rate, oxygen saturation, and temperature—the latter of which is not routinely measured in U.S. EMS systems, but fairly easily could be) are not physician-level; EMS personnel of various “levels” should easily be able to assess these and calculate the score, and in fact such a study is likely needed. Interestingly, the project did not involve prehospital lactate measurement. Handheld lactate meters are now available that look and work very much like the glucometers that EMS personnel have carried for decades. The feasibility of their use in the field has been demonstrated,2 with one small study published involving incorporation of lactate into a prehospital sepsis protocol.3 Bayer et al. rightly point out that “specific markers of sepsis do not exist,” but lactate is fairly sensitive for sepsis, and one wonders whether the addition of prehospital lactate measurement might improve the overall accuracy of a sepsis detection scheme. The big question, in my mind, is whether prehospital detection of sepsis matters. In the classic structure/process/outcome paradigm of Donabedian,4 a fair amount of work has been done in EMS to study and enhance structure and process, with no demonstrated outcomes
The author has no relevant financial information or potential conflicts of interest to disclose. A related article appears on page 868.
© 2015 by the Society for Academic Emergency Medicine doi: 10.1111/acem.12704
benefit. For example, EMS researchers have demonstrated that scene diagnosis of ST-elevation myocardial infarction and activation of the cardiac catheterization lab from the field is associated with lower door-toballoon times,5,6 but almost none of these studies have examined clinical benefit (lower mortality, smaller infarct size, better ventricular function, etc.). In a study by McKinney et al.,7 notification of the ED of an inbound stroke patient by EMS was associated with decreases in time to stroke team arrival, CT completion, and CT interpretation (although not time to treatment decision or tPA administration), but again, clinical outcomes were not examined. Similarly, Studnek et al.8 have shown that septic patients transported by EMS, with the treating paramedics documenting clinical impressions of sepsis (based on clinical judgment; no scoring system or other screening tool was used), had shorter ED times to antibiotics administration and sepsis “bundle” initiation than those whose paramedics did not suspect sepsis. The EMS-transported group (whether the paramedics suspected sepsis or not) also had shorter times to these two interventions than “walk-in” sepsis patients. Clinical outcomes were not examined, however; nor were interventions (process) provided by EMS, such as IV fluids or pressors. It seems fairly reasonable to assume that EMS personnel (physician or not) can detect sepsis with reasonable accuracy, either through clinical judgment or a diagnostic tool such as the one presented here by Bayer et al., but how would this earlier detection lead to better outcomes? The article provokes the questions of relative time reductions, frequency of patient encounters, and retention of skills/training of prehospital providers. This paradox is often encountered when comparing rural to urban EMS interventions with potential patient outcome opportunities. During my sabbatical at the Ambulance Service of New South Wales in 2011, a project was being designed to assess prehospital detection of sepsis, with aggressive IV hydration and perhaps even prehospital IV antibiotics (after blood cultures) for patients in frontier regions with prolonged (2 hr+) transport times. It was recognized, however, that the areas of the state with those prolonged transport times also have the fewest residents, suggesting that any given ambulance or paramedic might never encounter a patient meeting the project criteria. Conversely, suburban and urban areas
ISSN 1069-6563 PII ISSN 1069-6563583
845 845
846
where greater population density would make it more likely that any given paramedic might actually encounter one or more such patients in a year are also those areas where transport times are typically short enough to obviate the need for antibiotic administration in the field. Bayer et al. report that their EMS physicians started drawing blood cultures and giving IV antibiotics (ceftriaxone) in March 2012, but “[a]fter establishing this measure (antibiotics, drawing blood cultures), we recognized that diagnosing sepsis in the pre-hospital setting is more difficult as we had thought of, so we had the idea to create a score that would be a helpful tool for diagnosing sepsis in this setting” (personal communication, 11 March 2015). Is there any clinical value to just providing more aggressive prehospital IV fluid management in such cases? Is there clinical value to a “prehospital sepsis alert” or similar early notification of the receiving facility? Will the false positives mentioned by Bayer et al. (heat stroke, pulmonary embolism, etc.) dampen emergency physician enthusiasm for this sort of screening process? Will improving process measures (time to fluids, time to localization of source, time to antibiotics) lead to better outcomes? These and other facets of sepsis care need to be studied to determine the value of prehospital diagnosis. David C. Cone, MD ([email protected]) Editor-in-Chief Academic Emergency Medicine Yale University School of Medicine New Haven, CT
Supervising Editor: John Burton, MD.
Cone • PREHOSPITAL SEPSIS SCREEN
References 1. Bayer O, Schwarzkofp D, Stumme C, et al. An early warning scoring system to identify septic patients in the prehospital setting: the PRESEP score. Acad Emerg Med 2015;22:868–871. 2. van Beest PA, Mulder PJ, Oetomo SB, van den Broek B, Kuiper MA, Spronk PE. Measurement of lactate in a prehospital setting is related to outcome. Eur J Emerg Med 2009;16:318–22. 3. Guerra WF, Mayfield TR, Meyers MS, Clouatre AE, Riccio JC. Early detection and treatment of patients with severe sepsis by prehospital personnel. J Emerg Med 2013;44:1116–25. 4. Donabedian A. The quality of care. How can it be assessed? JAMA 1988;260:1743–8. 5. Cone DC, Lee CH, Van Gelder C. EMS activation of the cardiac catheterization laboratory is associated with process improvements in the care of myocardial infarction patients. Prehosp Emerg Care 2013;17:293– 8. 6. Eckstein M, Cooper E, Nguyen T, Pratt FD. Impact of paramedic transport with prehospital 12-lead electrocardiography on door-to-balloon times for patients with ST-segment elevation myocardial infarction. Prehosp Emerg Care 2009;13:203–6. 7. McKinney JS, Mylavarapu K, Lane J, Roberts V, Ohman-Strickland P, Merlin MA. Hospital prenotification of stroke patients by emergency medical services improves stroke time targets. J Stroke Cerebrovasc Dis 2013;22:113–8. 8. Studnek JR, Artho MR, Garner CL Jr, Jones AE. The impact of emergency medical services on the ED care of severe sepsis. Am J Emerg Med 2012;30:51–6.
The Prehospital Sepsis Screen: A Test in Search of an Application?
I
n this issue of Academic Emergency Medicine, Bayer and colleagues1 report on a study from Germany deriving a scoring system for the detection of sepsis in the prehospital setting. As one would expect, the authors started with the SIRS criteria, added other parameters commonly measured in the EMS setting, and used a multiple logistic regression model to derive the system. The area under the curve for the final model was a surprisingly good at 0.93 and remained at 0.93 using the simplified scoring system that the authors generated by transforming the regression weights into easily calculable numbers. It is worth noting that the EMS system that was involved in Bayer’s study is quite different from the EMS systems that most of our readers work with, in that all of the patients in the study were cared for by prehospital physicians (mainly anesthesiologists with intensive care experience). However, the parameters in the final model (heart rate, blood pressure, Glasgow Coma Scale score, respiratory rate, oxygen saturation, and temperature—the latter of which is not routinely measured in U.S. EMS systems, but fairly easily could be) are not physician-level; EMS personnel of various “levels” should easily be able to assess these and calculate the score, and in fact such a study is likely needed. Interestingly, the project did not involve prehospital lactate measurement. Handheld lactate meters are now available that look and work very much like the glucometers that EMS personnel have carried for decades. The feasibility of their use in the field has been demonstrated,2 with one small study published involving incorporation of lactate into a prehospital sepsis protocol.3 Bayer et al. rightly point out that “specific markers of sepsis do not exist,” but lactate is fairly sensitive for sepsis, and one wonders whether the addition of prehospital lactate measurement might improve the overall accuracy of a sepsis detection scheme. The big question, in my mind, is whether prehospital detection of sepsis matters. In the classic structure/process/outcome paradigm of Donabedian,4 a fair amount of work has been done in EMS to study and enhance structure and process, with no demonstrated outcomes
The author has no relevant financial information or potential conflicts of interest to disclose. A related article appears on page 868.
© 2015 by the Society for Academic Emergency Medicine doi: 10.1111/acem.12704
benefit. For example, EMS researchers have demonstrated that scene diagnosis of ST-elevation myocardial infarction and activation of the cardiac catheterization lab from the field is associated with lower door-toballoon times,5,6 but almost none of these studies have examined clinical benefit (lower mortality, smaller infarct size, better ventricular function, etc.). In a study by McKinney et al.,7 notification of the ED of an inbound stroke patient by EMS was associated with decreases in time to stroke team arrival, CT completion, and CT interpretation (although not time to treatment decision or tPA administration), but again, clinical outcomes were not examined. Similarly, Studnek et al.8 have shown that septic patients transported by EMS, with the treating paramedics documenting clinical impressions of sepsis (based on clinical judgment; no scoring system or other screening tool was used), had shorter ED times to antibiotics administration and sepsis “bundle” initiation than those whose paramedics did not suspect sepsis. The EMS-transported group (whether the paramedics suspected sepsis or not) also had shorter times to these two interventions than “walk-in” sepsis patients. Clinical outcomes were not examined, however; nor were interventions (process) provided by EMS, such as IV fluids or pressors. It seems fairly reasonable to assume that EMS personnel (physician or not) can detect sepsis with reasonable accuracy, either through clinical judgment or a diagnostic tool such as the one presented here by Bayer et al., but how would this earlier detection lead to better outcomes? The article provokes the questions of relative time reductions, frequency of patient encounters, and retention of skills/training of prehospital providers. This paradox is often encountered when comparing rural to urban EMS interventions with potential patient outcome opportunities. During my sabbatical at the Ambulance Service of New South Wales in 2011, a project was being designed to assess prehospital detection of sepsis, with aggressive IV hydration and perhaps even prehospital IV antibiotics (after blood cultures) for patients in frontier regions with prolonged (2 hr+) transport times. It was recognized, however, that the areas of the state with those prolonged transport times also have the fewest residents, suggesting that any given ambulance or paramedic might never encounter a patient meeting the project criteria. Conversely, suburban and urban areas
ISSN 1069-6563 PII ISSN 1069-6563583
845 845
846
where greater population density would make it more likely that any given paramedic might actually encounter one or more such patients in a year are also those areas where transport times are typically short enough to obviate the need for antibiotic administration in the field. Bayer et al. report that their EMS physicians started drawing blood cultures and giving IV antibiotics (ceftriaxone) in March 2012, but “[a]fter establishing this measure (antibiotics, drawing blood cultures), we recognized that diagnosing sepsis in the pre-hospital setting is more difficult as we had thought of, so we had the idea to create a score that would be a helpful tool for diagnosing sepsis in this setting” (personal communication, 11 March 2015). Is there any clinical value to just providing more aggressive prehospital IV fluid management in such cases? Is there clinical value to a “prehospital sepsis alert” or similar early notification of the receiving facility? Will the false positives mentioned by Bayer et al. (heat stroke, pulmonary embolism, etc.) dampen emergency physician enthusiasm for this sort of screening process? Will improving process measures (time to fluids, time to localization of source, time to antibiotics) lead to better outcomes? These and other facets of sepsis care need to be studied to determine the value of prehospital diagnosis. David C. Cone, MD ([email protected]) Editor-in-Chief Academic Emergency Medicine Yale University School of Medicine New Haven, CT
Supervising Editor: John Burton, MD.
Cone • PREHOSPITAL SEPSIS SCREEN
References 1. Bayer O, Schwarzkofp D, Stumme C, et al. An early warning scoring system to identify septic patients in the prehospital setting: the PRESEP score. Acad Emerg Med 2015;22:868–871. 2. van Beest PA, Mulder PJ, Oetomo SB, van den Broek B, Kuiper MA, Spronk PE. Measurement of lactate in a prehospital setting is related to outcome. Eur J Emerg Med 2009;16:318–22. 3. Guerra WF, Mayfield TR, Meyers MS, Clouatre AE, Riccio JC. Early detection and treatment of patients with severe sepsis by prehospital personnel. J Emerg Med 2013;44:1116–25. 4. Donabedian A. The quality of care. How can it be assessed? JAMA 1988;260:1743–8. 5. Cone DC, Lee CH, Van Gelder C. EMS activation of the cardiac catheterization laboratory is associated with process improvements in the care of myocardial infarction patients. Prehosp Emerg Care 2013;17:293– 8. 6. Eckstein M, Cooper E, Nguyen T, Pratt FD. Impact of paramedic transport with prehospital 12-lead electrocardiography on door-to-balloon times for patients with ST-segment elevation myocardial infarction. Prehosp Emerg Care 2009;13:203–6. 7. McKinney JS, Mylavarapu K, Lane J, Roberts V, Ohman-Strickland P, Merlin MA. Hospital prenotification of stroke patients by emergency medical services improves stroke time targets. J Stroke Cerebrovasc Dis 2013;22:113–8. 8. Studnek JR, Artho MR, Garner CL Jr, Jones AE. The impact of emergency medical services on the ED care of severe sepsis. Am J Emerg Med 2012;30:51–6.
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