Sepsis is a clinical syndrome that complicates severe infection. It’s characterized by signs of inflammation (e.g., vasodilation, elevated white cells, capillary permeability) occurring in tissues that are remote from the infection site.
If left untreated, this response can lead to multiple organ dysfunction syndrome , which causes high mortality. Early identification and the institution of goal-directed therapies can improve outcomes and mitigate progression to a state of shock.
Severe sepsis and septic shock are common and expensive medical emergencies. With an estimated yearly incidence of 751,000 cases (3.0 per 1,000 population) in the United States each year, severe sepsis and septic shock are associated with significant mortality and consumption of valuable healthcare resources with estimated costs of over $16.7 billion dollars annually.1,2
Recent studies demonstrate that early diagnosis of sepsis, within the first three hours of presentation, combined with aggressive fluid resuscitation, early antibiotics administration and lactate measurements, can improve the outcomes of patients with severe sepsis.3,4
Prehospital Sepsis Project
The Prehospital Sepsis Project (PSP) is a multifaceted study that aims to improve the out-of-hospital care of patients with sepsis by means of knowledge translation and enhancement of skills.5—7
Since 2005, our PSP study group has been researching sepsis in the out-of-hospital environment. One study in 2006 observed a poor understanding of the principles of diagnosis and management of sepsis in a cohort of U.S. advanced EMS providers, suggesting the need for enhancement of education.7 Other studies demonstrated that the out-of-hospital shock index and respiratory rate have high predictability for ICU admission,6 whereas recent PSP research has been focusing on the utility of point of care lactate in the prehospital arena.7,8
The Miami Sepsis Score
The Miami Sepsis Score was developed based on retrospective PSP research from 2004 and data collected between 2005 and 2006. Patients included were ≥ 18 years of age and transported by EMS to a major academic center with the diagnosis of sepsis as defined by ICD-9-CM diagnostic codes.
Physiologic variables studied included mean arterial pressure (MAP), heart rate (HR), respiratory rate (RR) and shock index (SI), which is the quotient of the HR divided by the systolic blood pressure (BP). A normal SI is approximately 0.5, but in shock (i.e., rising pulse rate with falling blood pressure), the index is abnormal at > 0.7. For example, a systolic BP of 80 combined with an HR of 125 yields an SI of 1.6.
This study demonstrated that out-of-hospital SI and RR are highly predictive of ICU admissions for patients presenting with sepsis.6
The Miami Sepsis Score has a maximum of 4 points, incorporating RR, fever and SI. (See Figure 1, below.) We defined fever as core body temperature of ≥ 38 degrees C (100.4 degrees F) and is the only obligate variable allotted with 1 point for the score, an SI ≥ 0.7 is given two points and an RR ≥ 22 is given one point for a total score of 4 points maximum. The patient population can be stratified based on the Miami Sepsis Score: 1 point is low risk, 2 points is moderate risk, and 3—4 points is high risk. We propose activation of a sepsis alert when a patient is at high risk.
Figure 1: The Miami Sepsis Score
Discussion
Aggressive resuscitation and early goal-directed therapy of patients with severe sepsis or septic shock results in an absolute mortality reduction of 16%–an effective reduction in the incidence of multiple organ dysfunction, and a decline in the use of healthcare resources.9
Several studies have looked at the value of simple but aggressive interventions such as early identification and fluid resuscitation in the first three hours of care of the patient with sepsis syndromes.1,2
The Society for Critical Care Medicine (SCCM) surviving sepsis campaign guidelines recommend a “three-hour bundle” that includes early identification, early antibiotics, lactate measurement and fluid resuscitation.4
Elements of this bundle are amenable to initiation in the prehospital setting, thus we believe that implementation of early identification by means of our Miami Sepsis Score, integrated with aggressive prehospital fluid resuscitation and even perhaps point of care lactate, can lead to earlier, more aggressive resuscitative care and the potential to positively affect outcomes.8,10,11
Although care of the sick and injured often begins in the prehospital setting, there has been limited data available related to predictors and interventions specific to sepsis in the prehospital work environment.
Knowledge of sepsis is relevant to the EMS provider, since the prehospital team frequently has first contact with the patient. Improved recognition of severe sepsis allows the EMS team to appreciate the patients’ acuity, and presumably, lead to a more informed decision, but also allows for improved communication between the crew, medical control and receiving facilities, as well as the initiation of important resuscitative interventional that can benefit the critical care continuum.
Analogous to prehospital alert protocols for trauma, stroke, or patients with myocardial infarctions, improved recognition of sepsis and early notification not only decreases time to treatment, but also allows for advance notice to be provided to the receiving ED.
Sepsis has been increasingly recognized by the medical community as an illness that requires immediate treatment and a large amount of resources. Therefore, advanced notification from EMS providers they’re transporting a septic patient may allow the receiving hospital to prepare for their arrival.
Our PSP study group has looked at the Critical Care Continuum in Sepsis.5—7 In this particular paper we believe that there’s potential for implementation of an early warning system for sepsis that integrates the Miami Sepsis Score, potentially assisting EMS in notifying hospitals and making point-of-entry decisions.
References:
1. Adrie C, Alberti C, Chaix-Couturier C, et al. Epidemiology and economic evaluation of severe sepsis in France: Age, severity, infection site, and place of acquisition (community, hospital, or intensive care unit) as determinants of workload and cost. J Crit Care. 2005;20(1):46—58.
2. Dellinger RP, Levy MM, Rhodes A, et al. Surviving Sepsis Campaign: International guidelines for management of severe sepsis and septic shock: 2012. Crit Care Med. 2013;41(2):580—637.
3. ProCESS Investigators, Yealy DM, Kellum JA, et al. A randomized trial of protocol-based care for early septic shock. N Engl J Med. 2014;370(18):1683—1693.
4. ARISE Investigators; ANZICS Clinical Trials Group, Peake SL, et al. Goal-directed resuscitation for patients with early septic shock. N Engl J Med. 2014;371(16):1496—1506.
5. Baez AA, Hanudel P, Wilcox SR. The Prehospital Sepsis Project: Out-of-hospital physiologic predictors of sepsis outcomes. Prehosp Disaster Med. 2013;28(6):632—635.
6. Baez AA, Hanudel P, Perez MT, et al. Prehospital Sepsis Project (PSP): Knowledge and attitudes of United States advanced out-of-hospital care providers. Prehosp Disaster Med. 2013;28(2):104—106.
7. Hanudel P, Wilcox S, Cadin E, et al. Prevalence of cryptic shock in a cohort of out-of-hospital sepsis patients: An argument for out-of-hospital point-of-care lactate. Ann Emerg Med. 2008;51(4):487—488.
8. Baez AA, Cochon L. Acute Care Diagnostics Collaboration: Assessment of a Bayesian clinical decision model integrating the Prehospital Sepsis Score and point-of-care lactate. Am J Emerg Med. 2016;34(2):193—196.
9. Rivers E, Nguyen B, Havstad S, et al. Early goal-directed therapy in the treatment of severe sepsis and septic shock. N Engl J Med. 2001;345(19):1368—1377.
10. Casserly B, Phillips GS, Schorr C, et al. Lactate measurements in sepsis-induced tissue hypoperfusion: Results from the Surviving Sepsis Campaign database. Crit Care Med. 2015;43(3):567—573.
11. Tobias AZ, Guyette FX, Seymour CW, et al. Pre-resuscitation lactate and hospital mortality in prehospital patients. Prehosp Emerg Care. 2014;18(3):321—327.
