Early management of sepsis in medical patients in rural Thailand: a single-center prospective observational study

Pneumonia-specific plasma metabolite profiles among patients hospitalised with infection in Southeast Asia

Background

Community-acquired pneumonia (CAP) is a major public health threat globally but is understudied in regions with the highest burden. The host immune response during infection may differ based on the site of infection. We hypothesised that analysis of the plasma metabolome in patients hospitalised with suspected infection could identify host response pathways specific to CAP.

Methods

We analysed the plasma metabolomes of adults admitted to a tertiary care hospital in northeastern Thailand with suspected community-acquired infection. Multivariable linear regression was performed for differential metabolite analyses and the global test was used for pathway analysis comparing patients with CAP versus non-CAP infections and uninfected controls. The least absolute shrinkage and selection operator (LASSO) was used to identify a parsimonious metabolite prognostic signature that was tested on an internal validation set to predict mortality.

Results

841 metabolites from 107 CAP patients and 152 non-CAP infected patients were analysed. 52 metabolites were differentially abundant between the CAP and non-CAP groups. CAP was characterised by increased metabolites involved in polyamine metabolism and decreased metabolites involved in lipid pathways. 13 pathways were differentially enriched between the CAP and non-CAP groups, consistent with individual metabolite analyses. 40 metabolites and four pathways were associated with CAP-specific mortality. A four-metabolite signature predicted 28-day mortality in CAP (area under the curve 0.79, 95% CI 0.62-0.97).

Conclusion

In a rural tropical setting, CAP induced a distinct metabolomic state compared to non-CAP presentations of infection that may reflect the activation of select host immune responses.

Plasma Metabolomics Reveals Distinct Biological and Diagnostic Signatures for Melioidosis

Rationale: The global burden of sepsis is greatest in low-resource settings. Melioidosis, infection with the gram-negative bacterium Burkholderia pseudomallei, is a frequent cause of fatal sepsis in endemic tropical regions such as Southeast Asia. Objectives: To investigate whether plasma metabolomics would identify biological pathways specific to melioidosis and yield clinically meaningful biomarkers. Methods: Using a comprehensive approach, differential enrichment of plasma metabolites and pathways was systematically evaluated in individuals selected from a prospective cohort of patients hospitalized in rural Thailand with infection. Statistical and bioinformatics methods were used to distinguish metabolomic features and processes specific to patients with melioidosis and between fatal and nonfatal cases. Measurements and Main Results: Metabolomic profiling and pathway enrichment analysis of plasma samples from patients with melioidosis (n = 175) and nonmelioidosis infections (n = 75) revealed a distinct immuno-metabolic state among patients with melioidosis, as suggested by excessive tryptophan catabolism in the kynurenine pathway and significantly increased levels of sphingomyelins and ceramide species. We derived a 12-metabolite classifier to distinguish melioidosis from other infections, yielding an area under the receiver operating characteristic curve of 0.87 in a second validation set of patients. Melioidosis nonsurvivors (n = 94) had a significantly disturbed metabolome compared with survivors (n = 81), with increased leucine, isoleucine, and valine metabolism, and elevated circulating free fatty acids and acylcarnitines. A limited eight-metabolite panel showed promise as an early prognosticator of mortality in melioidosis. Conclusions: Melioidosis induces a distinct metabolomic state that can be examined to distinguish underlying pathophysiological mechanisms associated with death. A 12-metabolite signature accurately differentiates melioidosis from other infections and may have diagnostic applications.

Sequential Organ Failure Assessment (SOFA) Score for predicting mortality in patients with sepsis in Vietnamese intensive care units: a multicentre, cross-sectional study

OBJECTIVES

To compare the accuracy of the Sequential Organ Failure Assessment (SOFA) and Acute Physiology and Chronic Health Evaluation II (APACHE II) Scores in predicting mortality among intensive care unit (ICU) patients with sepsis in a low-income and middle-income country.

DESIGN

A multicentre, cross-sectional study.

SETTING

A total of 15 adult ICUs throughout Vietnam.

PARTICIPANTS

We included all patients aged ≥18 years who were admitted to ICUs for sepsis and who were still in ICUs from 00:00 to 23:59 of the specified study days (ie, 9 January, 3 April, 3 July and 9 October of the year 2019).

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome was hospital all-cause mortality (hospital mortality). We also defined the secondary outcome as all-cause deaths in the ICU (ICU mortality).

RESULTS

Of 252 patients, 40.1% died in hospitals, and 33.3% died in ICUs. SOFA Score (areas under the receiver operating characteristic curve (AUROC): 0.688 (95% CI 0.618 to 0.758); cut-off value≥7.5; P_AUROC<0.001) and APACHE II Score (AUROC: 0.689 (95% CI 0.622 to 0.756); cut-off value ≥20.5; P_AUROC<0.001) both had a poor discriminatory ability for predicting hospital mortality. However, the discriminatory ability for predicting ICU mortality of SOFA (AUROC: 0.713 (95% CI 0.643 to 0.783); cut-off value≥9.5; P_AUROC<0.001) was fair and was better than that of APACHE II Score (AUROC: 0.672 (95% CI 0.603 to 0.742); cut-off value≥18.5; P_AUROC<0.001). A SOFA Score≥8 (adjusted OR (AOR): 2.717; 95% CI 1.371 to 5.382) and an APACHE II Score≥21 (AOR: 2.668; 95% CI 1.338 to 5.321) were independently associated with an increased risk of hospital mortality. Additionally, a SOFA Score≥10 (AOR: 2.194; 95% CI 1.017 to 4.735) was an independent predictor of ICU mortality, in contrast to an APACHE II Score≥19, for which this role did not.

CONCLUSIONS

In this study, SOFA and APACHE II Scores were worthwhile in predicting mortality among ICU patients with sepsis. However, due to better discrimination for predicting ICU mortality, the SOFA Score was preferable to the APACHE II Score in predicting mortality.Clinical trials registry - India: CTRI/2019/01/016898.

Predictive validity of the quick Sequential Organ Failure Assessment (qSOFA) score for the mortality in patients with sepsis in Vietnamese intensive care units

Background

The simple scoring systems for predicting the outcome of sepsis in intensive care units (ICUs) are few, especially for limited-resource settings. Therefore, this study aimed to evaluate the accuracy of the quick Sequential (Sepsis-Related) Organ Failure Assessment (qSOFA) score in predicting the mortality of ICU patients with sepsis in Vietnam.

Methods

We did a multicenter cross-sectional study of patients with sepsis (≥18 years old) presenting to 15 adult ICUs throughout Vietnam on the specified days (i.e., 9th January, 3rd April, 3rd July, and 9th October) representing the different seasons of 2019. The primary and secondary outcomes were the hospital and ICU all-cause mortalities, respectively. The area under the receiver operating characteristic curve (AUROC) was calculated to determine the discriminatory ability of the qSOFA score for deaths in the hospital and ICU. The cut-off value of the qSOFA scores was determined by the receiver operating characteristic curve analysis. Upon ICU admission, factors associated with the hospital and ICU mortalities were assessed in univariable and multivariable logistic models.

Results

Of 252 patients, 40.1% died in the hospital, and 33.3% died in the ICU. The qSOFA score had a poor discriminatory ability for both the hospital (AUROC: 0.610 [95% CI: 0.538 to 0.681]; cut-off value: ≥2.5; sensitivity: 34.7%; specificity: 84.1%; P_AUROC = 0.003) and ICU (AUROC: 0.619 [95% CI: 0.544 to 0.694]; cutoff value: ≥2.5; sensitivity: 36.9%; specificity: 83.3%; P_AUROC = 0.002) mortalities. However, multivariable logistic regression analyses show that the qSOFA score of 3 was independently associated with the increased risk of deaths in both the hospital (adjusted odds ratio, AOR: 3.358; 95% confidence interval, CI: 1.756 to 6.422) and the ICU (AOR: 3.060; 95% CI: 1.651 to 5.671).

Conclusion

In our study, despite having a poor discriminatory value, the qSOFA score seems worthwhile in predicting mortality in ICU patients with sepsis in limited-resource settings.

Clinical trial registration

Clinical trials registry–India: CTRI/2019/01/016898

The 28-Day Mortality Outcome of the Complete Hour-1 Sepsis Bundle in the Emergency Department

INTRODUCTION

The Surviving Sepsis Campaign published the Hour-1 Sepsis Bundle in 2018. The first-hour management of patients with sepsis in the emergency department (ED) is important, as suggested in the Hour-1 Sepsis Bundle. The objectives of the present study were to evaluate 28-day mortality and delayed septic shock with use of a complete and incomplete Hour-1 Sepsis Bundle in the ED.

METHODS

This prospective cohort study included adult patients with sepsis from March to July 2019. We followed the sepsis protocol used in the ED of a tertiary care hospital.

RESULTS

We enrolled 593 patients, with 55.9% in the complete Hour-1 Sepsis Bundle group. The 28-day mortality was 3.9% overall and no significant difference between the complete and incomplete Hour-1 Sepsis Bundle groups (3.6% vs. 4.2%, P = 0.707). Complete Hour-1 Sepsis Bundle treatment was not associated with 28-day mortality (adjusted OR = 2.04, 95% confidence interval [CI] = 0.72-5.74, P = 0.176) or delayed septic shock (adjusted OR = 0.74, 95% CI = 0.30-1.78, P = 0.499). Completion of each bundle did not affect outcomes of 28-day mortality and delayed septic shock.

CONCLUSIONS

The complete Hour-1 Sepsis Bundle treatment in the ED was not significantly associated with 28-day mortality and delayed septic shock.

TRIAL REGISTRATION

The trial was registered in the Thai Clinical Trial Registry, TCTR 20200526013.

Comparative clinical characteristics and outcomes of patients with community acquired bacteremia caused by Escherichia coli, Burkholderia pseudomallei and Staphylococcus aureus: A prospective observational study (Ubon-sepsis)

BACKGROUND

Community acquired bacteremia (CAB) is a common cause of sepsis in low and middle-income countries (LMICs). However, knowledge about factors associated with outcomes of CAB in LMICs is limited.

METHODOLOGY/PRINCIPAL FINDINGS

A prospective observational study (Ubon-sepsis) of adults admitted to a referral hospital with community-acquired infection in Northeastern Thailand was conducted between March 1, 2013 and February 1, 2017. In the present analysis, patients with a blood culture collected within 24 hours of admission that was positive for one of the three most common pathogens were studied. Clinical features, management, and outcomes of patients with each cause of CAB were compared. Of 3,806 patients presenting with community-acquired sepsis, 155, 131 and 37 patients had a blood culture positive for Escherichia coli, Burkholderia pseudomallei and Staphylococcus aureus, respectively. Of these 323 CAB patients, 284 (89%) were transferred from other hospitals. 28-day mortality was highest in patients with B. pseudomallei bactaeremia (66%), followed by those with S. aureus bacteraemia (43%) and E. coli (19%) bacteraemia. In the multivariable Cox proportional hazards model adjusted for age, sex, transfer from another hospital, empirical antibiotics prior to or during the transfer, and presence of organ dysfunction on admission, B. pseudomallei (aHR 3.78; 95%CI 2.31-6.21) and S. aureus (aHR 2.72; 95%CI 1.40-5.28) bacteraemias were associated with higher mortality compared to E. coli bacteraemia. Receiving empirical antibiotics recommended for CAB caused by the etiologic organism prior to or during transfer was associated with survival (aHR 0.58; 95%CI 0.38-0.88).

CONCLUSIONS/SIGNIFICANCE

Mortality of patients with CAB caused by B. pseudomallei was higher than those caused by S. aureus and E. coli, even after adjusting for presence of organ dysfunction on admission and effectiveness of empirical antibiotics received. Improving algorithms or rapid diagnostic tests to guide early empirical antibiotic may be key to improving CAB outcomes in LMICs.

Effectiveness of a sepsis programme in a resource-limited setting: a retrospective analysis of data of a prospective observational study (Ubon-sepsis)

OBJECTIVE

To evaluate the effectiveness of a Sepsis Fast Track (SFT) programme initiated at a regional referral hospital in Thailand in January 2015.

DESIGN

A retrospective analysis using the data of a prospective observational study (Ubon-sepsis) from March 2013 to January 2017.

SETTING

General medical wards and medical intensive care units (ICUs) of a study hospital.

PARTICIPANTS

Patients with community-acquired sepsis observed under the Ubon-sepsis cohort. Sepsis was defined as modified Sequential Organ Failure Assessment (SOFA) Score ≥2.

MAIN EXPOSURE

The SFT programme was a protocol to identify and initiate sepsis care on hospital admission, implemented at the study hospital in 2015. Patients in the SFT programme were admitted directly to the ICUs when available. The non-exposed group comprised of patients who received standard of care.

MAIN OUTCOME

The primary outcome was 28-day mortality. The secondary outcomes were measured sepsis management interventions.

RESULTS

Of 3806 sepsis patients, 903 (24%) were detected and enrolled in the SFT programme of the study hospital (SFT group) and 2903 received standard of care (non-exposed group). Patients in the SFT group had more organ dysfunction, were more likely to receive measured sepsis management and to be admitted directly to the ICU (19% vs 4%). Patients in the SFT group were more likely to survive (adjusted HR 0.72, 95% CI 0.58 to 0.88, p=0.001) adjusted for admission year, gender, age, comorbidities, modified SOFA Score and direct admission to the ICUs.

CONCLUSIONS

The SFT programme is associated with improved sepsis care and lower risk of death in sepsis patients in rural Thailand, where some critical care resources are limited. The survival benefit is observed even when all patients enrolled in the programme could not be admitted directly into the ICUs.

TRIAL REGISTRATION NUMBER

NCT02217592.

Lactoferrin is a dynamic protein in human melioidosis and is a TLR4-dependent driver of TNF-α release in Burkholderia thailandensis infection in vitro

Melioidosis is an often-severe tropical infection caused by Burkholderia pseudomallei (Bp) with high associated morbidity and mortality. Burkholderia thailandensis (Bt) is a closely related surrogate that does not require BSL-3 conditions for study. Lactoferrin is an iron-binding glycoprotein that can modulate the innate inflammatory response. Here we investigated the impact of lactoferrin on the host immune response in melioidosis. Lactoferrin concentrations were measured in plasma from patients with melioidosis and following ex vivo stimulation of blood from healthy individuals. Bt growth was quantified in liquid media in the presence of purified and recombinant human lactoferrin. Differentiated THP-1 cells and human blood monocytes were infected with Bt in the presence of purified and recombinant human lactoferrin, and bacterial intracellular replication and cytokine responses (tumor necrosis factor-α (TNF-α), interleukin-1β and interferon-γ) were measured. In a cohort of 49 melioidosis patients, non-survivors to 28 days had significantly higher plasma lactoferrin concentrations compared to survivors (median (interquartile range (IQR)): 326 ng/ml (230-748) vs 144 ng/ml (99-277), p<0.001). In blood stimulated with heat-killed Bp, plasma lactoferrin concentration significantly increased compared to unstimulated blood (median (IQR): 424 ng/ml (349-479) vs 130 ng/ml (91-214), respectively; p<0.001). Neither purified nor recombinant human lactoferrin impaired growth of Bt in media. Lactoferrin significantly increased TNF-α production by differentiated THP-1 cells and blood monocytes after Bt infection. This phenotype was largely abrogated when Toll-like receptor 4 (TLR4) was blocked with a monoclonal antibody. In sum, lactoferrin is produced by blood cells after exposure to Bp and lactoferrin concentrations are higher in 28-day survivors in melioidosis. Lactoferrin induces proinflammatory cytokine production after Bt infection that may be TLR4 dependent.

Presenting Symptoms in Sepsis: Is the Mnemonic "SEPSIS" Useful?

Background

The mnemonic “SEPSIS” (S = Slurred speech or confusion, E = Extreme shivering or muscle pain, fever, P = Passing no urine all day, S = Severe breathlessness, I = It feels like you are going to die, S = Skin mottled or discolored) has been developed by the World Sepsis Day committee, so as to raise public awareness of the symptomatic presentation of sepsis. However, this mnemonic has not been validated.

Methods

A retrospective, observational, single-center study was performed. All adult septic patients presenting at the emergency department of Songklanagarind Hospital from 2016 to 2019 were included and followed up until either hospital discharge or death.

Results

The study included 437 patients, comprising patients with sepsis (n = 250) and those with septic shock (n = 187). Patients presented with symptoms according to the mnemonic as follows: S = 97 (22.2%), E = 240 (54.9%), P = 18 (4.1%), S =181 (41.4%), I = 5 (1.1%), and S = 5 (1.1%). Sixty-five patients (14.9%) did not present with any sepsis-specific symptoms according to the mnemonic. Compared with patients who had at least one mnemonic symptom, a higher proportion of patients without mnemonic symptoms had underlying immunosuppression (24.6% vs 8.3%, P < 0.01) and were diagnosed with intraabdominal infection (38.5% vs 12.1%, P < 0.01). In a multivariable adjusted logistic regression model, vague-presenting symptoms were independently associated with in-hospital mortality (adjusted odds ratio 2.17, 95% confidence interval 1.30−3.61, P = 0.03).

Conclusion

Two components of the mnemonic “SEPSIS” were rarely reported: it feels like you are going to die and skin mottled or discolored. Using the mnemonic might lead to missed diagnoses, especially in immunosuppression and intraabdominal infection. This mnemonic should be revised for the local context.

sTREM-1 predicts mortality in hospitalized patients with infection in a tropical, middle-income country

BACKGROUND

Few studies of biomarkers as predictors of outcome in infection have been performed in tropical, low- and middle-income countries where the burden of sepsis is highest. We evaluated whether selected biomarkers could predict 28-day mortality in infected patients in rural Thailand.

METHODS

Four thousand nine hundred eighty-nine adult patients admitted with suspected infection to a referral hospital in northeast Thailand were prospectively enrolled within 24 h of admission. In a secondary analysis of 760 patients, interleukin-8 (IL-8), soluble tumor necrosis factor receptor 1 (sTNFR-1), angiopoietin-1 (Ang-1), angiopoietin-2 (Ang-2), and soluble triggering receptor expressed by myeloid cells 1 (sTREM-1) were measured in the plasma. Association with 28-day mortality was evaluated using regression; a parsimonious biomarker model was selected using the least absolute shrinkage and selection operator (LASSO) method. Discrimination of mortality was assessed by receiver operating characteristic curve analysis and verified by multiple methods.

RESULTS

IL-8, sTNFR-1, Ang-2, and sTREM-1 concentrations were strongly associated with death. LASSO identified a three-biomarker model of sTREM-1, Ang-2, and IL-8, but sTREM-1 alone provided comparable mortality discrimination (p = 0.07). sTREM-1 alone was comparable to a model of clinical variables (area under receiver operating characteristic curve [AUC] 0.81, 95% confidence interval [CI] 0.77-0.85 vs AUC 0.79, 95% CI 0.74-0.84; p = 0.43). The combination of sTREM-1 and clinical variables yielded greater mortality discrimination than clinical variables alone (AUC 0.83, 95% CI 0.79-0.87; p = 0.004).

CONCLUSIONS

sTREM-1 predicts mortality from infection in a tropical, middle-income country comparably to a model derived from clinical variables and, when combined with clinical variables, can further augment mortality prediction.

TRIAL REGISTRATION

The Ubon-sepsis study was registered on ClinicalTrials.gov ( NCT02217592 ), 2014.