Sepsis: A Threat That Needs a Global Solution

Defining sepsis in small animals

OBJECTIVE

To discuss the definitions of sepsis in human and veterinary medicine.

DESIGN

International, multicenter position statement on the need for consensus definitions of sepsis in veterinary medicine.

SETTING

Veterinary private practice and university teaching hospitals.

ANIMALS

Dogs and cats.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Sepsis is a life-threatening condition associated with the body's response to an infection. In human medicine, sepsis has been defined by consensus on 3 occasions, most recently in 2016. In veterinary medicine, there is little uniformity in how sepsis is defined and no consensus on how to identify it clinically. Most publications rely on modified criteria derived from the 1991 and 2001 human consensus definitions. There is a divergence between the human and veterinary descriptions of sepsis and no consensus on how to diagnose the syndrome. This impedes research, hampers the translation of pathophysiology insights to the clinic, and limits our abilities to optimize patient care. It may be time to formally define sepsis in veterinary medicine to help the field move forward. In this narrative review, we present a synopsis of prior attempts to define sepsis in human and veterinary medicine, discuss developments in our understanding, and highlight some criticisms and shortcomings of existing schemes.

CONCLUSIONS

This review is intended to serve as the foundation of current efforts to establish a consensus definition for sepsis in small animals and ultimately generate evidence-based criteria for its recognition in veterinary clinical practice.

Robust and Multifunctional Therapeutic Nanoparticles against Peritonitis-Induced Sepsis

Apart from bacterial growth and endotoxin generation, the excessive production of reactive radicals linked with sepsis also has a substantial impact on triggering an inflammatory response and further treatment failure. Hence, the rational design and fabrication of robust and multifunctional nanoparticles (NPs) present a viable means of overcoming this dilemma. In this study, we used antibiotic polymyxin B (PMB) and antioxidant natural polyphenolic protocatechualdehyde (PCA) to construct robust and multifunctional NPs for sepsis treatment, leveraging the rich chemistries of PCA. The PMB release profile from the NPs demonstrated pH-responsive behavior, which allowed the NPs to exhibit effective bacterial killing and radical scavenging properties. Data from in vitro cells stimulated with H2O2 and lipopolysaccharide (LPS) showed the multifunctionalities of NPs, including intracellular reactive oxygen species (ROS) scavenging, elimination of the bacterial toxin LPS, inhibiting macrophage M1 polarization, and anti-inflammation capabilities. Additionally, in vivo studies further demonstrated that NPs could increase the effectiveness of sepsis treatment by lowering the bacterial survival ratio, the expression of the oxidative marker malondialdehyde (MDA), and the expression of inflammatory cytokine TNF-α. Overall, this work provides ideas of using those robust and multifunctional therapeutic NPs toward enhanced sepsis therapy efficiency.

Predicting sepsis-related mortality and ICU admissions from telephone triage information of patients presenting to out-of-hours GP cooperatives with acute infections: A cohort study of linked routine care databases

BACKGROUND

General practitioners (GPs) often assess patients with acute infections. It is challenging for GPs to recognize patients needing immediate hospital referral for sepsis while avoiding unnecessary referrals. This study aimed to predict adverse sepsis-related outcomes from telephone triage information of patients presenting to out-of-hours GP cooperatives.

METHODS

A retrospective cohort study using linked routine care databases from out-of-hours GP cooperatives, general practices, hospitals and mortality registration. We included adult patients with complaints possibly related to an acute infection, who were assessed (clinic consultation or home visit) by a GP from a GP cooperative between 2017-2019. We used telephone triage information to derive a risk prediction model for sepsis-related adverse outcome (infection-related ICU admission within seven days or infection-related death within 30 days) using logistic regression, random forest, and neural network machine learning techniques. Data from 2017 and 2018 were used for derivation and from 2019 for validation.

RESULTS

We included 155,486 patients (median age of 51 years; 59% females) in the analyses. The strongest predictors for sepsis-related adverse outcome were age, type of contact (home visit or clinic consultation), patients considered ABCD unstable during triage, and the entry complaints"general malaise", "shortness of breath" and "fever". The multivariable logistic regression model resulted in a C-statistic of 0.89 (95% CI 0.88-0.90) with good calibration. Machine learning models performed similarly to the logistic regression model. A "sepsis alert" based on a predicted probability >1% resulted in a sensitivity of 82% and a positive predictive value of 4.5%. However, most events occurred in patients receiving home visits, and model performance was substantially worse in this subgroup (C-statistic 0.70).

CONCLUSION

Several patient characteristics identified during telephone triage of patients presenting to out-of-hours GP cooperatives were associated with sepsis-related adverse outcomes. Still, on a patient level, predictions were not sufficiently accurate for clinical purposes.

Prompt Identification of Sepsis on Hospital Floors: Are Healthcare Professionals Ready for the Implementation of the Hour-1 Bundle?

Early intervention in sepsis management with recognized therapeutic targets may be effective in lowering sepsis-related morbidity and mortality, although this necessitates timely identification of sepsis by healthcare professionals. The present study aimed to assess knowledge levels, attitudes, and agreement among physicians regarding the Surviving Sepsis Campaign (SSC) guidelines (more specifically, the Hour-1 bundle). A quantitative, descriptive, cross-sectional study was conducted among physicians working in different clinical settings in Karachi, Pakistan, using a self-administered questionnaire. The mean cumulative knowledge score of the respondents towards SSC was 6.8 ± 2.1 (out of 10), where a total of n = 127 respondents (51.62%) had a strong understanding of the SSC guidelines, compared to n = 78 (31.7%) and n = 41 (16.7%) respondents with fair and inadequate knowledge, respectively. The majorly known bundle elements by the respondents were to administer broad-spectrum antibiotics (89.8%, n = 221), the need for taking blood cultures before administering antibiotics (87.8%, n = 216), and measurement of blood lactate levels (75.6%, n = 186). Experienced physicians were more likely to use norepinephrine as the first-choice vasopressor (p < 0.001). Female respondents were more likely to consider the duration of antibiotic therapy to be determined according to the site of infection, the microbiological etiology, the patient’s response to treatment, and the likelihood of achieving adequate source control (p = 0.001). The current study concluded that respondents had an optimistic approach and frequently practice in accordance with the SSC guidelines, while some respondents were not up to date with the most recent guidelines. There is a need for further interventions and continuous medical education to encourage physicians towards appropriate use of the recommended guiding principles for improving treatment outcomes in sepsis patients.

Fragments of bombinakinin M exist in lipopolysaccharide-stimulated skin secretions of Bombina maxima and show lipopolysaccharide-neutralizing activity

Lipopolysaccharide (LPS) is a major pathogen-associated pattern molecule that can initiate lethal sepsis. Bioactive peptides in amphibian skin secretions, especially antimicrobial peptides, are essential components of the host immune system and help fight the microbial invasion. In this study, two peptides: peptide 1 (KINRKGPRPPG) and peptide 2 (INRKGPRPPG) were isolated, from skin secretions of the Chinese red belly frog (Bombina maxima). After stimulation with LPS, peptide 1 showed direct LPS-binding activity, low cytotoxicity, immunoregulatory functions in vitro, and neutralizing LPS effects in animal models. Thus, natural peptide 1 exhibits potential as an ideal candidate against LPS.

Early warning for healthcare acquired infections in neonatal care units in a low-resource setting using routinely collected hospital data: The experience from Haiti, 2014-2018

In low-resource settings, detection of healthcare-acquired outbreaks in neonatal units relies on astute clinical staff to observe unusual morbidity or mortality from sepsis as microbiological diagnostics are often absent. We aimed to generate reliable (and automated) early warnings for potential clusters of neonatal late onset sepsis using retrospective data that could signal the start of an outbreak in an NCU in Port au Prince, Haiti, using routinely collected data on neonatal admissions. We constructed smoothed time series for late onset sepsis cases, late onset sepsis rates, neonatal care unit (NCU) mortality, maternal admissions, neonatal admissions and neonatal antibiotic consumption. An outbreak was defined as a statistical increase in any of these time series indicators. We created three outbreak alarm classes: 1) thresholds: weeks in which the late onset sepsis cases exceeded four, the late onset sepsis rates exceeded 10% of total NCU admissions and the NCU mortality exceeded 15%; 2) differential: late onset sepsis rates and NCU mortality were double the previous week; and 3) aberration: using the improved Farrington model for late onset sepsis rates and NCU mortality. We validated pairs of alarms by calculating the sensitivity and specificity of the weeks in which each alarm was launched and comparing each alarm to the weeks in which a single GNB positive blood culture was reported from a neonate. The threshold and aberration alarms were the strongest predictors for current and future NCU mortality and current LOS rates (p<0.0002). The aberration alarms were also those with the highest sensitivity, specificity, negative predictive value, and positive predictive value. Without microbiological diagnostics in NCUs in low-resource settings, applying these simple algorithms to routinely collected data show great potential to facilitate early warning for possible healthcare-acquired outbreaks of LOS in neonates. The methods used in this study require validation across other low-resource settings.

Sensitivity and specificity of a quick sequential [Sepsis-Related] organ failure assessment sepsis screening tool

AIM

There is limited evidence on the diagnostic accuracy of a quick Sequential [Sepsis-Related] Organ Failure Assessment (qSOFA) sepsis screening (SS) tool in developing nation health settings. The aim of this study was to test the diagnostic accuracy of a qSOFA-based SS tool, and the predictive validity of the qSOFA score in hospital ward patients from Argentina.

METHODS

Prospective observational study. Patients (≥18 years, without sepsis) were recruited within 24-48 hours of admission to a 169-bed tertiary referral private hospital in Buenos Aires. The index test was the qSOFA-based SS tool, and the reference standard sepsis diagnosed at discharge blindly evaluated with reference to the Sepsis-3.

RESULTS

In 1151 patients (median age 69.9 [IQR, 29.0]); 47 (4.1%) had sepsis, 413 (35.9%) had infection and 691 (60.0%) other diagnoses at discharge. The qSOFA-based SS tool (index test) had moderate sensitivity (60%), good specificity (89%), a very low positive (19%) and very high negative (98%) predictive value for sepsis diagnosed at discharge according to the Sepsis-3 criteria (reference standard). For the same outcome, the qSOFA score in isolation had a reasonable predictive validity area under receiver operating characteristics curve 0.77 (95% CI 0.70-0.83) P < 0.001.

CONCLUSION

The qSOFA score could reasonably discriminate patients at risk of developing sepsis; qSOFA-based screening may be valuable where no screening criteria are in place.

Admission Blood Glucose Is Associated With the 30-Days Mortality in Septic Patients: A Retrospective Cohort Study

Background: Sepsis, as one of the severe diseases, is frequently observed in critically ill patients, especially concurrent with diabetes. Whether admission blood glucose is associated with the prognosis, and outcome of septic patients is still debatable.

Methods: We retrospectively reviewed and analyzed the demographic characteristics of septic patients in the Medical Information Mart for Intensive Care III (MIMIC III, version 1.4) between June 2001 and October 2012. The Chi-square and Fisher's exact tests were used for the comparison of qualitative variables among septic patients with different glucose levels and the 30-day mortality in septic patients with diabetes or not. Univariate and stepwise multivariate Cox regression analyses were used to determine the risk factors for 30-day mortality. Kaplan-Meier analysis was conducted to reveal the different 30-day survival probabilities in each subgroup.

Results: A total of 2,948 septic patients (910 cases with diabetes, 2,038 cases without diabetes) were ultimately included in the study. The 30-day mortality was 32.4% (956/2,948 cases) in the overall population without any difference among diabetic and non-diabetic septic patients (p = 1.000). Admission blood glucose levels <70 mg/dl were only observed to be significantly associated with the 30-day mortality of septic patients without diabetes (hazard ratio (HR) = 2.48, p < 0.001). After adjusting for confounders, age >65 years (HR = 1.53, p = 0.001), the Sequential Organ Failure Assessment (SOFA) score >5 (HR = 2.26, p < 0.001), lactic acid >2 mmol/L (Lac, HR = 1.35, p = 0.024), and platelet abnormality (<100 k/ul: HR = 1.49; >300 k/ul: HR = 1.36, p < 0.001) were the independent risk factors for 30-day mortality in septic patients with diabetes. In non-diabetes population, age >65 years (HR = 1.53, p < 0.001), non-White or non-Black patients (HR = 1.30, p = 0.004), SOFA score >5 (HR = 1.56, p < 0.001), blood glucose <70 mg/dl (HR = 1.91, p = 0.003), anion gap (AG) >2 mmol/L (HR = 1.60, p < 0.001), Lac (HR = 1.61, p < 0.001), urea nitrogen >21 mg/dl (HR = 1.45, p = 0.001), alanine aminotransferase (ALT, HR = 1.31, p = 0.009), total bilirubin >1.2 mg/dl (HR = 1.20, p = 0.033), and low hemoglobin (HR = 1.34, p = 0.001) were the independent risk factors for 30-day mortality.

Conclusions: Our results indicate admission blood glucose, especially in terms of <70 mg/dl, is the key signaling in predicting the worse 30-day survival probability of septic patients without diabetes, which could help clinicians to make a more suitable and precise treatment modality in dealing with septic patients.

Improving sepsis screening and care in a developing nation health setting: A description of implementation

Evidence on sepsis screening and care in developing nations is insufficient to inform implementation practices in hospital wards. The aim of this multi-method study was to describe and evaluate the implementation of a three-step intervention (sepsis screening, alert activation, care) in five wards in Argentina in 2017. The implementation involved three stages: (1) context assessment, (2) development/participation in implementation strategies, and (3) evaluation of intervention adherence. Results were variable. The context assessment (Stage 1) demonstrated the value of education, proactivity towards care and team structures. Strategies developed (Stage 2) included sepsis screening and response guide, education, team rounding, posters, champions, audit/feedback and knowledge brokering. In Stage 3, staff screened 92% patients (506/547) for sepsis at ≥60% of set times; only 33% (21/64) patients had a sepsis alert activated when needed. A similar proportion of patients who had alerts activated (n = 16, 76%) or not (n = 32, 74%) received at least one element of care. The use of implementation strategies resulted in adherence to some aspects of the intervention. Future research is needed to improve sepsis screening and alert activation and care in this setting.

What Animal Models Can Tell Us About Long-Term Psychiatric Symptoms in Sepsis Survivors: a Systematic Review

Lower sepsis mortality rates imply that more patients are discharged from the hospital, but sepsis survivors often experience sequelae, such as functional disability, cognitive impairment, and psychiatric morbidity. Nevertheless, the mechanisms underlying these long-term disabilities are not fully understood. Considering the extensive use of animal models in the study of the pathogenesis of neuropsychiatric disorders, it seems adopting this approach to improve our knowledge of postseptic psychiatric symptoms is a logical approach. With the purpose of gathering and summarizing the main findings of studies using animal models of sepsis-induced psychiatric symptoms, we performed a systematic review of the literature on this topic. Thus, 140 references were reviewed, and most of the published studies suggested a time-dependent recovery from behavior alterations, despite the fact that some molecular alterations persist in the brain. This review reveals that animal models can be used to understand the mechanisms that underlie anxiety and depression in animals recovering from sepsis.

A comprehensive assessment of multi-system responses to a renal inoculation of uropathogenic E. coli in swine

BACKGROUND

The systemic responses to infection and its progression to sepsis remains poorly understood. Progress in the field has been stifled by the shortcomings of experimental models which include poor replication of the human condition. To address these challenges, we developed and piloted a novel large animal model of severe infection that is capable of generating multi-system clinically relevant data.

METHODS

Male swine (n = 5) were anesthetized, mechanically ventilated, and surgically instrumented for continuous hemodynamic monitoring and serial blood sampling. Animals were inoculated with uropathogenic E. coli by direct injection into the renal parenchyma and were maintained until a priori endpoints were met. The natural history of the infection was studied. Animals were not resuscitated. Multi-system data were collected hourly to 6 hours; all animals were euthanized at predetermined physiologic endpoints.

RESULTS

Core body temperature progressively increased from mean (SD) 37.9(0.8)°C at baseline to 43.0(1.2)°C at experiment termination (p = 0.006). Mean arterial pressure did not begin to decline until 6h post inoculation, dropping from 86(9) mmHg at baseline to 28(5) mmHg (p = 0.005) at termination. Blood glucose progressively declined but lactate levels did not elevate until the last hours of the experiment. There were also temporal changes in whole blood concentrations of a number of metabolites including increases in the catecholamine precursors, tyrosine (p = 0.005) and phenylalanine (p = 0.005). Lung, liver, and kidney function parameters worsened as infection progressed and at study termination there was histopathological evidence of injury in these end-organs.

CONCLUSION

We demonstrate a versatile, multi-system, longitudinal, swine model of infection that could be used to further our understanding of the mechanisms that underlie infection-induced multi-organ dysfunction and failure, optimize resuscitation protocols and test therapeutic interventions. Such a model could improve translation of findings from the bench to the bedside, circumventing a significant obstacle in sepsis research.

Implementing a quick Sequential (Sepsis-Related) Organ Failure Assessment sepsis screening tool: an interrupted times series study

OBJECTIVE

The aim of this study was to evaluate the outcomes of implementing a sepsis screening (SS) tool based on the quick Sequential [Sepsis-Related] Organ Failure Assessment (qSOFA) and the presence of confirmed/suspected infection. The implementation of the 6-h bundle was also evaluated.

DESIGN

Interrupted times series with prospective data collection.

SETTING

Five hospital wards in a developing nation, Argentina.

PARTICIPANTS

A total of 1151 patients (≥18 years) recruited within 24-48 h of hospital admission.

INTERVENTION

The qSOFA-based SS tool and the 6-h bundle.

MAIN OUTCOME MEASURES

The primary outcome was the timing of implementation of the first 6-h bundle element. Secondary outcomes were related to the adherence to the screening procedures.

RESULTS

Of 1151 patients, 145 (12.6%) met the qSOFA-based SS tool criteria, among them intervention (39/64) patients received the first 6-h bundle element earlier (median 8 h; 95% confidence interval (CI): 0.1-16) than baseline (48/81) patients (median 22 h; 95% CI: 3-41); these times, however, did not differ significantly (P = 0.525). Overall, 47 (4.1%) patients had sepsis; intervention patients (18/25) received the first 6-h bundle element sooner (median 5 h; 95% CI: 4-6) than baseline patients (15/22) did (median 12 h; 95% CI: 0-33); however, times were not significantly different (P = 0.470). While intervention patients were screened regularly, only one-third of patients who required sepsis alerts had them activated.

CONCLUSION

The implementation of the qSOFA-based SS tool resulted in early, but not significantly improved, provision of 6-h bundle care. Screening procedures were regularly conducted, but sepsis alerts rarely activated. Further research is needed to better understand the implementation of sepsis care in developing settings.

The Prevalence and Outcomes of Sepsis in Adult Patients in Two Hospitals in Malawi

There are an estimated 19.4 million sepsis cases every year, many of them in low-income countries. The newly adopted definition of sepsis uses Sequential Organ Failure Assessment Score (SOFA), a score which is not feasible in many low-resource settings. A simpler quick-SOFA (qSOFA) based solely on vital signs score has been devised for identification of suspected sepsis. This study aimed to determine in-hospital prevalence and outcomes of sepsis, as defined as suspected infection and a qSOFA score of 2 or more, in two hospitals in Malawi. The secondary aim was to evaluate qSOFA as a predictor of mortality. A cross-sectional study of adult in-patients in two hospitals in Malawi was conducted using prospectively collected single-day point-prevalence data and in-hospital follow-up. Of 1,135 participants, 81 (7.1%) had sepsis. Septic patients had a higher hospital mortality rate (17.5%) than non-septic infected patients (9.0%, p = 0.027, odds ratio 2.1 [1.1-4.3]), although the difference was not statistically significant after adjustment for baseline characteristics. For in-hospital mortality among patients with suspected infection, qSOFA ≥ 2 had a sensitivity of 31.8%, specificity of 82.1%, a positive predictive value of 17.5%, and a negative predictive value of 91.0%. In conclusion, sepsis is common and is associated with a high risk of death in admitted patients in hospitals in Malawi. In low-resource settings, qSOFA score that uses commonly available vital signs data may be a tool that could be used for identifying patients at risk-both for those with and without a suspected infection.

Predictive Accuracy of the Quick Sepsis-related Organ Failure Assessment Score in Brazil. A Prospective Multicenter Study

Rationale: Although proposed as a clinical prompt to sepsis based on predictive validity for mortality, the Quick Sepsis-related Organ Failure Assessment (qSOFA) score is often used as a screening tool, which requires high sensitivity.

Objectives: To assess the predictive accuracy of qSOFA for mortality in Brazil, focusing on sensitivity.

Methods: We prospectively collected data from two cohorts of emergency department and ward patients. Cohort 1 included patients with suspected infection but without organ dysfunction or sepsis (22 hospitals: 3 public and 19 private). Cohort 2 included patients with sepsis (54 hospitals: 24 public and 28 private). The primary outcome was in-hospital mortality. The predictive accuracy of qSOFA was examined considering only the worst values before the suspicion of infection or sepsis.

Measurements and Main Results: Cohort 1 contained 5,460 patients (mortality rate, 14.0%; 95% confidence interval [CI], 13.1–15.0), among whom 78.3% had a qSOFA score less than or equal to 1 (mortality rate, 8.3%; 95% CI, 7.5–9.1). The sensitivity of a qSOFA score greater than or equal to 2 for predicting mortality was 53.9% and the 95% CI was 50.3 to 57.5. The sensitivity was higher for a qSOFA greater than or equal to 1 (84.9%; 95% CI, 82.1–87.3), a qSOFA score greater than or equal to 1 or lactate greater than 2 mmol/L (91.3%; 95% CI, 89.0–93.2), and systemic inflammatory response syndrome plus organ dysfunction (68.7%; 95% CI, 65.2–71.9). Cohort 2 contained 4,711 patients, among whom 62.3% had a qSOFA score less than or equal to 1 (mortality rate, 17.3%; 95% CI, 15.9–18.7), whereas in public hospitals the mortality rate was 39.3% (95% CI, 35.5–43.3).

Conclusions: A qSOFA score greater than or equal to 2 has low sensitivity for predicting death in patients with suspected infection in a developing country. Using a qSOFA score greater than or equal to 2 as a screening tool for sepsis may miss patients who ultimately die. Using a qSOFA score greater than or equal to 1 or adding lactate to a qSOFA score greater than or equal to 1 may improve sensitivity.

Clinical trial registered with www.clinicaltrials.gov (NCT03158493).

Availability of resources to treat sepsis in Brazil: a random sample of Brazilian institutions

OBJECTIVE

To characterize resource availability from a nationally representative random sample of intensive care units in Brazil.

METHODS

A structured online survey of participating units in the Sepsis PREvalence Assessment Database (SPREAD) study, a nationwide 1-day point prevalence survey to assess the burden of sepsis in Brazil, was sent to the medical director of each unit.

RESULTS

A representative sample of 277 of the 317 invited units responded to the resources survey. Most of the hospitals had fewer than 500 beds (94.6%) with a median of 14 beds in the intensive care unit. Providing care for public-insured patients was the main source of income in two-thirds of the surveyed units. Own microbiology laboratory was not available for 26.8% of the surveyed intensive care units, and 10.5% did not always have access to blood cultures. Broad spectrum antibiotics were not always available in 10.5% of surveyed units, and 21.3% could not always measure lactate within three hours. Those institutions with a high resource availability (158 units, 57%) were usually larger and preferentially served patients from the private health system compared to institutions without high resource availability. Otherwise, those without high resource availability did not always have broad-spectrum antibiotics (24.4%), vasopressors (4.2%) or crystalloids (7.6%).

CONCLUSION

Our study indicates that a relevant number of units cannot perform basic monitoring and therapeutic interventions in septic patients. Our results highlight major opportunities for improvement to adhere to simple but effective interventions in Brazil.