Postoperative sepsis. Curr Opin Crit Care. 2011;17:396-401. [PMID: 21677580 DOI: 10.1097/mcc.0b013e328348bee2]

Improving Statewide Post-Operative Sepsis Performance Measurement Using Hospital Risk Adjustment Within a Surgical Collaborative

Background: The Georgia Quality Improvement Program (GQIP) surgical collaborative participating hospitals have shown consistently poor performance in the post-operative sepsis category of National Surgical Quality Improvement Program data as compared with national benchmarks. We aimed to compare crude versus risk-adjusted post-operative sepsis rankings to determine high and low performers amongst GQIP hospitals. Patients and Methods: The cohort included intra-abdominal general surgery patients across 10 collaborative hospitals from 2015 to 2020. The American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) sepsis definition was used among all hospitals for case abstraction and NSQIP data were utilized to train and validate a multivariable risk-adjustment model with post-operative sepsis as the outcome. This model was used to rank GQIP hospitals by risk-adjusted post-operative sepsis rates. Rankings between crude and risk-adjusted post-operative sepsis rankings were compared ordinally and for changes in tertile. Results: The study included 20,314 patients with 595 cases of post-operative sepsis. Crude 30-day post-operative sepsis risk among hospitals ranged from 0.81 to 5.11. When applying the risk-adjustment model which included: age, American Society of Anesthesiology class, case complexity, pre-operative pneumonia/urinary tract infection/surgical site infection, admission status, and wound class, nine of 10 hospitals were re-ranked and four hospitals changed performance tertiles. Conclusions: Inter-collaborative risk-adjusted post-operative sepsis rankings are important to present. These metrics benchmark collaborating hospitals, which facilitates best practice exchange from high to low performers.

Pharmacokinetic and pharmacodynamic considerations for antifungal therapy optimisation in the treatment of intra-abdominal candidiasis

Intra-abdominal candidiasis (IAC) is one of the most common of invasive candidiasis observed in critically ill patients. It is associated with high mortality, with up to 50% of deaths attributable to delays in source control and/or the introduction of antifungal therapy. Currently, there is no comprehensive guidance on optimising antifungal dosing in the treatment of IAC among the critically ill. However, this form of abdominal sepsis presents specific pharmacokinetic (PK) alterations and pharmacodynamic (PD) challenges that risk suboptimal antifungal exposure at the site of infection in critically ill patients. This review aims to describe the peculiarities of IAC from both PK and PD perspectives, advocating an individualized approach to antifungal dosing. Additionally, all current PK/PD studies relating to IAC are reviewed in terms of strength and limitations, so that core elements for the basis of future research can be provided.

Identifying Effective Biomarkers for Accurate Pancreatic Cancer Prognosis Using Statistical Machine Learning

Pancreatic cancer (PC) has one of the lowest survival rates among all major types of cancer. Consequently, it is one of the leading causes of mortality worldwide. Serum biomarkers historically correlate well with the early prognosis of post-surgical complications of PC. However, attempts to identify an effective biomarker panel for the successful prognosis of PC were almost non-existent in the current literature. The current study investigated the roles of various serum biomarkers including carbohydrate antigen 19-9 (CA19-9), chemokine (C-X-C motif) ligand 8 (CXCL-8), procalcitonin (PCT), and other relevant clinical data for identifying PC progression, classified into sepsis, recurrence, and other post-surgical complications, among PC patients. The most relevant biochemical and clinical markers for PC prognosis were identified using a random-forest-powered feature elimination method. Using this informative biomarker panel, the selected machine-learning (ML) classification models demonstrated highly accurate results for classifying PC patients into three complication groups on independent test data. The superiority of the combined biomarker panel (Max AUC-ROC = 100%) was further established over using CA19-9 features exclusively (Max AUC-ROC = 75%) for the task of classifying PC progression. This novel study demonstrates the effectiveness of the combined biomarker panel in successfully diagnosing PC progression and other relevant complications among Egyptian PC survivors.

Development and validation of a patient-specific model to predict postoperative SIRS in older patients: A two-center study

Introduction

Postoperative systemic inflammatory response syndrome (SIRS) is common in surgical patients especially in older patients, and the geriatric population with SIRS is more susceptible to sepsis, MODS, and even death. We aimed to develop and validate a model for predicting postoperative SIRS in older patients.

Methods

Patients aged ≥65 years who underwent general anesthesia in two centers of Third Affiliated Hospital of Sun Yat-sen University from January 2015 to September 2020 were included. The cohort was divided into training and validation cohorts. A simple nomogram was developed to predict the postoperative SIRS in the training cohort using two logistic regression models and the brute force algorithm. The discriminative performance of this model was determined by area under the receiver operating characteristics curve (AUC). The external validity of the nomogram was assessed in the validation cohort.

Results

A total of 5,904 patients spanning from January 2015 to December 2019 were enrolled in the training cohort and 1,105 patients from January 2020 to September 2020 comprised the temporal validation cohort, in which incidence rates of postoperative SIRS were 24.6 and 20.2%, respectively. Six feature variables were identified as valuable predictors to construct the nomogram, with high AUCs (0.800 [0.787, 0.813] and 0.822 [0.790, 0.854]) and relatively balanced sensitivity (0.718 and 0.739) as well as specificity (0.718 and 0.729) in both training and validation cohorts. An online risk calculator was established for clinical application.

Conclusion

We developed a patient-specific model that may assist in predicting postoperative SIRS among the aged patients.

Sepsis-Associated Coagulopathy Predicts Hospital Mortality in Critically Ill Patients With Postoperative Sepsis

BACKGROUND

The incidence of coagulopathy, which was responsible for poor outcomes, was commonly seen among patients with sepsis. In the current study, we aim to determine whether the presence of sepsis-associated coagulopathy (SAC) predicts the clinical outcomes among critically ill patients with postoperative sepsis.

METHODS

We conducted a single-center retrospective cohort study by including patients with sepsis admitted to surgical ICU of Chinese PLA General Hospital from January 1, 2014 to December 31, 2018. Baseline characteristics and clinical outcomes were compared with respect to the presence of SAC. Kaplan-Meier analysis was applied to calculate survival rate, and Log-rank test was carried out to compare the differences between two groups. Furthermore, multivariable Cox and logistic and linear regression analysis were performed to assess the relationship between SAC and clinical outcomes, including hospital mortality, development of septic shock, and length of hospital stay (LOS), respectively. Additionally, both sensitivity and subgroup analyses were performed to further testify the robustness of our findings.

RESULTS

A total of 175 patients were included in the current study. Among all included patients, 41.1% (72/175) ICU patients were identified as having SAC. In-hospital mortality rates were significantly higher in the SAC group when compared to that of the No SAC group (37.5% vs. 11.7%; p < 0.001). By performing univariable and multivariable regression analyses, presence of SAC was demonstrated to significantly correlate with an increased in-hospital mortality for patients with sepsis in surgical ICU [Hazard ratio (HR), 3.75; 95% Confidence interval (CI), 1.90-7.40; p < 0.001]. Meanwhile, a complication of SAC was found to be the independent predictor of the development of septic shock [Odds ratio (OR), 4.11; 95% CI, 1.81-9.32; p = 0.001], whereas it was not significantly associated with prolonged hospital LOS (OR, 0.97; 95% CI, 0.83-1.14; p = 0.743).

CONCLUSION

The presence of SAC was significantly associated with increased risk of in-hospital death and septic shock among postoperative patients with sepsis admitted to ICU. Moreover, there was no statistical difference of hospital LOS between the SAC and no SAC groups.

Prediction of Postoperative Sepsis Based on Changes in Presepsin Levels of Critically Ill Patients with Acute Kidney Injury after Abdominal Surgery

Presepsin (PSP) is a viable biomarker for the detection of bacterial infection, but it lacks accuracy when acute kidney injury (AKI) develops. Herein, we evaluated the diagnostic and prognostic value of PSP in predicting postoperative sepsis after abdominal surgery respective to the degree of AKI. A total of 311 patients who underwent abdominal surgery and were admitted to a surgical intensive care unit were enrolled and classified into non-AKI, mild-AKI (stage 1, stage 2 and stage 3 without renal replacement therapy (RRT)) and severe-AKI (stage 3 with RRT) group, according to the Kidney Disease Improving Global Outcomes criteria. In each group, PSP and other biomarkers were statistically analyzed between non-sepsis and postoperative sepsis at the admission (T0), 24 h (T1), 48 h (T2) and 72 h (T3) after surgery. In non-AKI and mild-AKI group, PSP levels were significantly higher in postoperative sepsis than non-sepsis group, whereas no difference was detected in the severe-AKI group. Cutoff values of PSP in the mild-AKI group for the prediction of postoperative sepsis were 544 pg/mL (AUC: 0.757, p < 0.001) at T0 and 458.5 pg/mL (AUC: 0.743, p < 0.001) at T1, significantly higher than in non-AKI group. In multivariate analysis, predictors of postoperative sepsis in the mild-AKI group were PSP at T2 (odds ratio (OR): 1.002, p = 0.044) and PSP at T3 (OR: 1.001, p = 0.049). PSP can be useful for predicting newly developed sepsis in patients with transient AKI after abdominal surgery with modified cutoff values.

Bacterial translocation in patients undergoing major gastrointestinal surgery and its role in postoperative sepsis

Bacteria of the human intestinal microflora have a dual role. They promote digestion and are part of a defense mechanism against pathogens. These bacteria could become potential pathogens under certain circumstances. The term “bacterial translocation” describes the passage of bacteria of the gastrointestinal tract through the intestinal mucosa barrier to mesenteric lymph nodes and other organs. In some cases, the passage of bacteria and endotoxins could result in blood stream infections and in multiple organ failure. Open elective abdominal surgery more frequently results in malfunction of the intestinal barrier and subsequent bacterial translocation and blood stream infections than laparoscopic surgery. Postoperative sepsis is a common finding in patients who have undergone non-elective abdominal surgeries, including trauma patients treated with laparotomy. Postoperative sepsis is an emerging issue, as it changes the treatment plan in surgical patients and prolongs hospital stay. The association between bacterial translocation and postoperative sepsis could provide novel treatment options.

Increased mortality and altered local immune response in secondary peritonitis after previous visceral operations in mice

Postoperative peritonitis is characterized by a more severe clinical course than other forms of secondary peritonitis. The pathophysiological mechanisms behind this phenomenon are incompletely understood. This study used an innovative model to investigate these mechanisms, combining the models of murine Colon Ascendens Stent Peritonitis (CASP) and Surgically induced Immune Dysfunction (SID). Moreover, the influence of the previously described anti-inflammatory reflex transmitted by the vagal nerve was characterized. SID alone, or 3 days before CASP were performed in female C57BL/6 N mice. Subdiaphragmatic vagotomy was performed six days before SID with following CASP. The immune status was assessed by FACS analysis and measurement of cytokines. Local intestinal inflammatory changes were characterized by immunohistochemistry. Mortality was increased in CASP animals previously subjected to SID. Subclinical bacteremia occurred after SID, and an immunosuppressive milieu occurred secondary to SID just before the induction of CASP. Previous SID modified the pattern of intestinal inflammation induced by CASP. Subdiaphragmatic vagotomy had no influence on sepsis mortality in our model of postoperative peritonitis. Our results indicate a surgery-induced inflammation of the small intestine and the peritoneal cavity with bacterial translocation, which led to immune dysfunction and consequently to a more severe peritonitis.

The Impacts of Deep Surgical Site Infections on Readmissions, Length of Stay, and Costs: A Matched Case-Control Study Conducted in an Academic Hospital in the Netherlands

OBJECTIVE

This study aimed to evaluate the impacts of deep surgical site infections (dSSIs) regarding hospital readmissions, prolonged length of stay (LoS), and estimated costs.

PATIENTS AND METHODS

We designed and applied a matched case-control observational study using the electronic health records at the University Medical Center Groningen in the Netherlands. We compared patients with dSSI and non-SSI, matched on the basis of having similar procedures. A prevailing topology of surgeries categorized as clean, clean-contaminated, contaminated, and dirty was applied.

RESULTS

Out of a total of 12,285 patients, 393 dSSI were identified as cases, and 2864 patients without SSIs were selected as controls. A total of 343 dSSI patients (87%) and 2307 (81%) controls required hospital readmissions. The median LoS was 7 days (P25-P75: 2.5-14.5) for dSSI patients and 5 days (P25-P75: 1-9) for controls (p-value: <0.001). The estimated mean cost per hospital admission was €9,016 (SE±343) for dSSI patients and €5,409 (SE±120) for controls (p<0.001). Independent variables associated with dSSI were patient's age ≥65 years (OR: 1.334; 95% CI: 1.036-1.720), the use of prophylactic antibiotics (OR: 0.424; 95% CI: 0.344-0.537), and neoplasms (OR: 2.050; 95% CI: 1.473-2.854).

CONCLUSION

dSSI is associated with increased costs, prolonged LoS, and increased readmission rates. Elevated risks were seen for elderly patients and those with neoplasms. Additionally, a protective effect of prophylactic antibiotics was found.

Application of machine learning to the prediction of postoperative sepsis after appendectomy

BACKGROUND

We applied various machine learning algorithms to a large national dataset to model the risk of postoperative sepsis after appendectomy to evaluate utility of such methods and identify factors associated with postoperative sepsis in these patients.

METHODS

The National Surgery Quality Improvement Program database was used to identify patients undergoing appendectomy between 2005 and 2017. Logistic regression, support vector machines, random forest decision trees, and extreme gradient boosting machines were used to model the occurrence of postoperative sepsis.

RESULTS

In the study, 223,214 appendectomies were identified; 2,143 (0.96%) were indicated as having postoperative sepsis. Logistic regression (area under the curve 0.70; 95% confidence interval, 0.68-0.73), random forest decision trees (area under the curve 0.70; 95% confidence interval, 0.68-0.73), and extreme gradient boosting (area under the curve 0.70; 95% confidence interval, 0.68-0.73) afforded similar performance, while support vector machines (area under the curve 0.51; 95% confidence interval, 0.50-0.52) had worse performance. Variable importance analyses identified preoperative congestive heart failure, transfusion, and acute renal failure as predictors of postoperative sepsis.

CONCLUSION

Machine learning methods can be used to predict the development of sepsis after appendectomy with moderate accuracy. Such predictive modeling has potential to ultimately allow for preoperative recognition of patients at risk for developing postoperative sepsis after appendectomy thus facilitating early intervention and reducing morbidity.

A Machine Learning-Based Prediction of Hospital Mortality in Patients With Postoperative Sepsis

Introduction: The incidence of postoperative sepsis is continually increased, while few studies have specifically focused on the risk factors and clinical outcomes associated with the development of sepsis after surgical procedures. The present study aimed to develop a mathematical model for predicting the in-hospital mortality among patients with postoperative sepsis. Materials and Methods: Surgical patients in Medical Information Mart for Intensive Care (MIMIC-III) database who simultaneously fulfilled Sepsis 3.0 and Agency for Healthcare Research and Quality (AHRQ) criteria at ICU admission were incorporated. We employed both extreme gradient boosting (XGBoost) and stepwise logistic regression model to predict the in-hospital mortality among patients with postoperative sepsis. Consequently, the model performance was assessed from the angles of discrimination and calibration. Results: We included 3,713 patients who fulfilled our inclusion criteria, in which 397 (10.7%) patients died during hospitalization, and 3,316 (89.3%) patients survived through discharge. Fluid-electrolyte disturbance, coagulopathy, renal replacement therapy (RRT), urine output, and cardiovascular surgery were important features related to the in-hospital mortality. The XGBoost model had a better performance in both discriminatory ability (c-statistics, 0.835 vs. 0.737 and 0.621, respectively; AUPRC, 0.418 vs. 0.280 and 0.237, respectively) and goodness of fit (visualized by calibration curve) compared to the stepwise logistic regression model and baseline model. Conclusion: XGBoost model has a better performance in predicting hospital mortality among patients with postoperative sepsis in comparison to the stepwise logistic regression model. Machine learning-based algorithm might have significant application in the development of early warning system for septic patients following major operations.

Epidemiological Characteristics of Postoperative Sepsis

BACKGROUND

Postoperative sepsis is a major type of sepsis. Sociodemographic characteristics, incidence trends, surgical procedures, comorbidities, and organ system dysfunctions related to the disease burden of postoperative sepsis episodes are unclear.

METHODS

We analyzed epidemiological characteristics of postoperative sepsis based on the ICD-9-CM codes for the years 2002 to 2013 using the Longitudinal Health Insurance Databases of Taiwan's National Health Insurance Research Database.

RESULTS

We identified 5,221 patients with postoperative sepsis and 338,279 patients without postoperative sepsis. The incidence of postoperative sepsis increased annually with a crude mean of 0.06% for patients aged 45-64 and 0.34% over 65 years. Patients with postoperative sepsis indicated a high risk associated with the characteristics, male sex (OR:1.375), aged 45-64 or ≥ 65 years (OR:2.639 and 5.862), low income (OR:1.390), aged township (OR:1.269), agricultural town (OR:1.266), and remote township (OR:1.205). Splenic surgery (OR:7.723), Chronic renal disease (OR:1.733), cardiovascular dysfunction (OR:2.441), and organ system dysfunctions had the highest risk of postoperative sepsis.

CONCLUSION

Risk of postoperative sepsis was highest among men, older, and low income. Patients with splenic surgery, chronic renal comorbidity, and cardiovascular system dysfunction exhibited the highest risk for postoperative sepsis. The evaluation of high-risk factors assists in reducing the disease burden.

[Acute postoperative sepsis mimicking symptomology suspicious for malignant hyperthermia: case report]

BACKGROUND

Sepsis is a life-threatening organ dysfunction with non-specific clinical features that can mimic other clinical conditions with hyper metabolic state such as malignant hyperthermia. Perioperatively anesthesia providers come across such scenarios, which are extremely challenging with the need for urgent intervention.

OBJECTIVE

To illustrate the need for early intervention and consultation for added assistance to approach and rule out malignant hyperthermia and other possible causes during such a scenario.

CASE REPORT

A 63-year-old male underwent an uneventful elective flexible cystoscopy and transrectal ultrasound-guided prostate biopsy. Postoperatively he developed symptoms raising suspicion for malignant hyperthermia. Immediately malignant hyperthermia protocol was initiated that included administration of dantrolene and consultation of malignant hyperthermia association hotline along with other diagnostic and interventional management aimed at patient optimization. While early administration of dantrolene helped in hemodynamically stabilizing the patient, the consultation with other providers and malignant hyperthermia association hotline along with repeated examinations and lab works helped in ruling out malignant hyperthermia as the possible diagnosis. The patient later recovered in the intensive care unit where he was treated for the bacteremia that grew in his blood cultures.

CONCLUSIONS

Sepsis shares clinical symptoms that mimic malignant hyperthermia. While sepsis rapidly progresses to secondary injuries, malignant hyperthermia is life threatening. Providing ideal care requires good clinical judgment and a high level of suspicion where timely and appropriate care such as early administration of dantrolene and consultation of malignant hyperthermia association hotline for added assistance can influence positive outcomes.

Acute postoperative sepsis mimicking symptomology suspicious for malignant hyperthermia: case report

Background

Sepsis is a life-threatening organ dysfunction with non-specific clinical features that can mimic other clinical conditions with hyper metabolic state such as malignant hyperthermia. Perioperatively anesthesia providers come across such scenarios, which are extremely challenging with the need for urgent intervention.

Objective

To illustrate the need for early intervention and consultation for added assistance to approach and rule out malignant hyperthermia and other possible causes during such a scenario.

Case report

A 63-year-old male underwent an uneventful elective flexible cystoscopy and transrectal ultrasound-guided prostate biopsy. Postoperatively he developed symptoms raising suspicion for malignant hyperthermia. Immediately malignant hyperthermia protocol was initiated that included administration of dantrolene and consultation of malignant hyperthermia association hotline along with other diagnostic and interventional management aimed at patient optimization. While early administration of dantrolene helped in hemodynamically stabilizing the patient, the consultation with other providers and malignant hyperthermia association hotline along with repeated examinations and lab works helped in ruling out malignant hyperthermia as the possible diagnosis. The patient later recovered in the intensive care unit where he was treated for the bacteremia that grew in his blood cultures.

Conclusions

Sepsis shares clinical symptoms that mimic malignant hyperthermia. While sepsis rapidly progresses to secondary injuries, malignant hyperthermia is life threatening. Providing ideal care requires good clinical judgment and a high level of suspicion where timely and appropriate care such as early administration of dantrolene and consultation of malignant hyperthermia association hotline for added assistance can influence positive outcomes.

Predictors of early weaning failure from mechanical ventilation in critically ill patients after emergency gastrointestinal surgery: A retrospective study

Mechanical ventilation (MV) is the most common therapeutic modality used for critically ill patients. However, prolonged MV is associated with high morbidity and mortality. Therefore, it is important to avoid both premature extubation and unnecessary prolongation of MV. Although some studies have determined the predictors of early weaning success and failure, only a few have investigated these factors in critically ill surgical patients who require postoperative MV. The aim of this study was to evaluate predictors of early weaning failure from MV in critically ill patients who had undergone emergency gastrointestinal (GI) surgery.The medical records of 3327 adult patients who underwent emergency GI surgery between January 2007 and December 2016 were reviewed retrospectively. Clinical and laboratory parameters before surgery and within 2 days postsurgery were investigated.This study included 387 adult patients who required postoperative MV. A low platelet count (adjusted odds ratio [OR]: 0.995; 95% confidence interval [CI]: 0.991-1.000; P = .03), an elevated delta neutrophil index (DNI; adjusted OR: 1.025; 95% CI: 1.005-1.046; P = .016), a delayed spontaneous breathing trial (SBT; adjusted OR: 14.152; 95% CI: 6.571-30.483; P < .001), and the presence of postoperative shock (adjusted OR: 2.436; 95% CI: 1.138-5.216; P = .022) were shown to predict early weaning failure from MV in the study population.Delayed SBT, a low platelet count, an elevated DNI, and the presence of postoperative shock are independent predictors of early weaning failure from MV in critically ill patients after emergency GI surgery.

The association between pre-operative sepsis and 30-day mortality in hip fracture patients-A cohort study

BACKGROUND

Post-operative sepsis considerably increases mortality, but the extent of pre-operative sepsis in hip fracture patients and its consequences are sparsely elucidated. The aim of this study was to assess the association between pre-operative sepsis and 30-day mortality after hip fracture surgery.

METHODS

We conducted a retrospective analysis of data collected among 1894 patients who underwent hip fracture surgery in the Capital Region of Denmark in 2014 (NCT03201679). Data on vital signs, cultures and laboratory data were obtained. Sepsis was defined as a positive culture of any kind and presence of systemic inflammatory response syndrome within 24 hours and was assessed within 72 hours before surgery and 30 days post-operatively. Primary outcome was 30-day mortality. Secondary outcomes included length of hospital stay and admission to intensive care unit.

RESULTS

A total of 144 (7.6%) of the hip fracture patients met the criteria for pre-operative sepsis. The 30-day mortality was 13.9% in patients with pre-operative sepsis as compared to 9.0% in those without (OR 1.69, 95% CI [1.00; 2.85], P = .08). Patients with pre-operative sepsis had longer hospital stays (median 10 days vs 9 days, mean difference 2.1 [SD 9.4] days, P = .03), and higher frequency of ICU admission (11.1% vs 2.7%, OR 4.15, 95% CI [2.19; 7.87], P < .0001).

CONCLUSION

Pre-operative sepsis in hip fracture patients was associated with an increased length of hospital stay and tended to increase mortality. Pre-operative sepsis in hip fracture patients merits more intensive surveillance and increased attention to timely treatment.

The impact of post-operative sepsis on mortality after hospital discharge among elective surgical patients: a population-based cohort study

Background

Our aim in the present study was to assess the mortality impact of hospital-acquired post-operative sepsis up to 1 year after hospital discharge among adult non-short-stay elective surgical patients.

Methods

We conducted a population-based, retrospective cohort study of all elective surgical patients admitted to 82 public acute hospitals between 1 January 2007 and 31 December 2012 in New South Wales, Australia. All adult elective surgical admission patients who stayed in hospital for ≥4 days and survived to discharge after post-operative sepsis were identified using the Admitted Patient Data Collection records linked with the Registry of Births, Deaths, and Marriages. We assessed post-discharge mortality rates at 30 days, 60 days, 90 days and 1 year and compared them with those of patients without post-operative sepsis.

Results

We studied 144,503 survivors to discharge. Of these, 1857 (1.3%) had experienced post-operative sepsis. Their post-discharge mortality rates at 30 days, 60 days, 90 days and 1 year were 4.6%, 6.7%, 8.1% and 13.5% (vs 0.7%, 1.2%, 1.5% and 3.8% in the non-sepsis cohort), respectively (P < 0.0001 for all). After adjustment for patient and hospital characteristics, post-operative sepsis remained independently associated with a higher mortality risk (30-day mortality HR 2.75, 95% CI 2.14–3.53; 60-day mortality HR 2.45, 95% CI 1.94–3.10; 90-day mortality HR 2.31, 95% CI 1.85–2.87; 1-year mortality HR 1.71, 95% CI 1.46–2.00). Being older than 75 years of age (HR 3.50, 95% CI 1.56–7.87) and presence of severe/very severe co-morbidities as defined by Charlson co-morbidity index (severe vs normal HR 2.05, 95% CI 1.45–2.89; very severe vs normal HR 2.17, 95% CI 1.49–3.17) were the only other significant independent predictors of increased 1-year mortality.

Conclusions

Among elective surgical patients, post-operative sepsis is independently associated with increased post-discharge mortality up to 1 year after hospital discharge. This risk is particularly high in the first month, in older age patients and in the presence of severe/very severe co-morbidities. This high-risk population can be targeted for interventions.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-016-1596-7) contains supplementary material, which is available to authorized users.

Mechanism and effect of excessive inflammatory response in perioperative period of abdominal surgery

Inflammation is an important pathophysiological change in the perioperative period of abdominal surgery. Moderate inflammatory plays a positive role in wound healing, but excessive inflammation is harmful to the body and is a major cause of postoperative complications and the common pathway of multiple organ dysfunction syndrome. Therefore, intervention of excessive inflammation response in the perioperative period can reduce the morbidity and mortality of patients. However, the current understanding of the pathophysiological process of excessive inflammatory response during the perioperative period is still in the primary stage. This article systematically reviews the induced factors, mechanism and pathophysiological changes of excessive inflammatory response during the perioperative period of abdominal surgery as well as its harm to and influence on the body.

Postoperative sepsis prediction in patients undergoing major cancer surgery

BACKGROUND

Cancer patients are at increased risk for postoperative sepsis. However, studies addressing the issue are lacking. We sought to identify preoperative and intraoperative predictors of 30-d sepsis after major cancer surgery (MCS) and derive a postoperative sepsis risk stratification tool.

METHODS

Patients undergoing one of nine MCSs (gastrointestinal, urological, gynecologic, or pulmonary) were identified within the American College of Surgeons National Surgical Quality Improvement Program (2005-2011, n = 69,169). Multivariable adjusted analyses (MVA) were performed to identify the predictors of postoperative sepsis. A composite sepsis risk score (CSRS) was constructed using the regression coefficients of predictors significant on MVA. The score was stratified into low, intermediate, and high risk, and its predictive accuracy for sepsis, septic shock, and mortality was assessed using the area under the curve analysis.

RESULTS

Overall, 4.3% (n = 2954) of patients developed postoperative sepsis. In MVA, Black race (odds ratio [OR] = 1.30, P = 0.002), preoperative hematocrit <30 (OR = 1.40, P = 0.022), cardiopulmonary and cerebrovascular comorbidities (P < 0.010), American Society of Anesthesiologists score >3 (P < 0.05), operative time (OR = 1.002, P < 0.001), surgical approach (OR = 1.81, P < 0.001), and procedure type (P < 0.001) were significant predictors of postoperative sepsis. CSRS demonstrated favorable accuracy in predicting postoperative sepsis, septic shock, and mortality (area under the curve 0.72, 0.75, and 0.74, respectively). Furthermore, CSRS risk stratification demonstrated high concordance with sepsis rates, 1.3% in low-risk patients versus 9.7% in high-risk patients. Similarly, 30-d mortality rate varied from 0.5% to 5.5% (10-fold difference) in low-risk patients versus high-risk patients.

CONCLUSIONS

Our study identifies the major risk factors for 30-d sepsis after MCS. These risk factors have been converted into a simple, accurate bedside sepsis risk score. This tool might facilitate improved patient-physician interaction regarding the risk of postoperative sepsis and septic shock.

Alternative splicing of SMPD1 in human sepsis

Acid sphingomyelinase (ASM or sphingomyelin phosphodiesterase, SMPD) activity engages a critical role for regulation of immune response and development of organ failure in critically ill patients. Beside genetic variation in the human gene encoding ASM (SMPD1), alternative splicing of the mRNA is involved in regulation of enzymatic activity. Here we show that the patterns of alternatively spliced SMPD1 transcripts are significantly different in patients with systemic inflammatory response syndrome and severe sepsis/septic shock compared to control subjects allowing discrimination of respective disease entity. The different splicing patterns might contribute to the better understanding of the pathophysiology of human sepsis.

Positive regulatory effects of perioperative probiotic treatment on postoperative liver complications after colorectal liver metastases surgery: a double-center and double-blind randomized clinical trial

BACKGROUND

Colorectal liver metastases (CLM) occur frequently and postoperative intestinal infection is a common complication. Our previous study showed that probiotics could decrease the rate of infectious complications after colectomy for colorectal cancer. To determine the effects of the perioperative administration of probiotics on serum zonulin levels which is a marker of intestinal permeability and the subsequent impact on postoperative infectious complications in patients with CLM.

METHODS

150 patients with CLM were randomly divided into control group (n = 68) and probiotics group (n = 66). Probiotics and placebo were given orally for 6 days preoperatively and 10 days postoperatively to control group and probiotics group respectively. We used the local resection for metastatic tumor ,while for large tumor, the segmental hepatectomy. Postoperative outcome were recorded. Furthermore, complications in patients with normal intestinal barrier function and the relation with serum zonulin were analyzed to evaluate the impact on the liver barrier dysfunction.

RESULTS

The incidence of infectious complications in the probiotics group was lower than control group. Analysis of CLM patients with normal postoperative intestinal barrier function paralleled with the serum zonulin level. And probiotics could also reduce the concentration of serum zonulin (P = 0.004) and plasma endotoxin (P < 0.001).

CONCLUSION

Perioperative probiotics treatment could reduce the serum zonulin level, the rate of postoperative septicemia and maintain the liver barrier in patients undergoing CLM surgery. we propose a new model about the regulation of probiotics to liver barrier via clinical regulatory pathway. We recommend the preoperative oral intake of probiotics combined with postoperative continued probiotics treatment in patients who undergo CLM surgery.

TRIAL REGISTRATION

ChiCTR-TRC- 12002841 . 2012/12/21.

In vivo study of the effects of exogenous hydrogen sulfide on lung mitochondria in acute lung injury in rats

Background

Acute lung injury (ALI) is a serious disease with high incidence in ICU, and impaired mitochondria function plays a significant role in ALI. In this study, we examined the possible roles of exogenous hydrogen sulfide (H₂S) in lung mitochondria regulation in ALI rats.

Methods

The rat ALI model was induced by an intra-tongue vein Lipopolysaccharide (LPS) injection. We used sodium hydrosulphide (NaHS) as the H₂S donor. We randomly divided 40 Sprague–Dawley rats into five groups: control, LPS injury, LPS + low-dose NaHS (0.78 mg•kg^-1), LPS + middle-dose NaHS (1.56 mg•kg^-1), and LPS + high-dose NaHS (3.12 mg•kg^-1). Rats were killed 3 h after NaHS administration. We calculated a semi-quantitative histological index of lung injury assessments and measured the lung wet-to-dry weight ratio. We further analyzed serum for interleukin-1β levels using enzyme-linked immunosorbent assays. We observed lung mitochondria ultrastructures with an electron microscope. We examined oxidative stress markers in lung mitochondria and the mitochondrial swelling and activity. We analyzed lung mitochondria and cytosol Cyt-c protein expression using Western blotting.

Results

Compared to the control group, the quantitative assessment score index, wet-to-dry weight ratios, and interleukin-1β content in the LPS injury group were significantly increased and the mitochondrial ultrastructure damaged. Furthermore, mitochondrial activity, adenosine triphosphatease, superoxide dismutase, glutathione peroxidase, and mitochondrial Cyt-c protein expression were significantly decreased, and malondialdehyde content, mitochondrial swelling, and cytosol Cyt-c protein expression were significantly increased in the LPS injury group compared to the control group. These effects were lessened by NaHS.

Conclusion

Exogenous H₂S provided a protective effect against ALI by decreasing the mitochondrial lipid peroxidation level and protecting the cell structure in the LPS-induced rat models. Its regulatory effect on lung mitochondria is positively correlated with the dosage.

Basic and clinical research on the regulation of the intestinal barrier by Lactobacillus and its active protein components: a review with experience of one center

Probiotics got protective effects on the intestinal barrier. Our present study is to review the basic and clinical progress on the regulation of the intestinal barrier by Lactobacillus and its active protein components, combing the study of our center. Our study have isolated the active component of micro integral membrane protein (MIMP) within the media place of the integral membrane protein of Lactobacillus plantarum, which was verified about the protective effects against the intestinal epithelial dysfunction. On the other hand, we also found the effects of perioperative use of probiotics in the prevention and treatment of postoperative intestinal barrier dysfunction, and reduction of the postoperative infective complications. In this review, we would like to report the founding of our center, involving in the basic and clinical research progress of regulation of intestinal barrier by Lactobacillus and its active protein component MIMP. Furthermore, we may also promote our following studies about the MIMP and its clinical verification.

Pronounced inflammatory response to endotoxaemia during nighttime: a randomised cross-over trial

Background

Circadian variation in bodily functions has been shown to impact health in acute and chronic medical conditions. Little is known about the relationship between circadian rhythm and sepsis in humans. We aimed to investigate circadian variations in the host response in a human endotoxaemia model.

Design and Methods

A cross-over study, where 12 healthy young men received E. coli endotoxin (lipopolysaccharide, LPS) 0.3 ng/kg at 12 noon and, on another day, at 12 midnight. Blood samples were analysed for pro- and anti-inflammatory cytokines: tumour-necrosis factor (TNF)-alpha, soluble TNF receptors (sTNF-R)-1 and -2, interleukin (IL)-1beta, IL-1 receptor antagonist (IL-1Ra), IL-6, and IL-10 as well as YKL-40 and the oxidative stress markers malondialdehyde (MDA), ascorbic acid (AA) and dehydroascorbic acid (DHA) before and at 2, 4, 6 and 8 hours after LPS administration.

Results

The levels of MDA and IL-10 where significantly higher during the day time (P<0.05) whereas levels of TNF-alpha, sTNF-RI, sTNF-RII, IL-1Ra, IL-6, and YKL-40 were higher (P<0.01 for all comparisons) during the night time. No significant differences were seen in the levels of AA and DHA.

Conclusion

A day-night difference in the acute phase response to endotoxaemia exists in healthy volunteers with a more pronounced inflammatory response during the night time. This circadian difference in the response to endotoxaemia may play an important role in the clinical setting and should be investigated further.

Diagnostic value of serum leptin and a promising novel diagnostic model for sepsis

Diagnosis of sepsis in critically ill patients is important to reduce morbidity and mortality. The present study was conducted to determine the role of serum leptin in the early diagnosis of sepsis and to establish a diagnostic model for sepsis. A retrospective study was conducted of 331 patients from an intensive care unit. All patients underwent consistent blood collection at 6:00 a.m. every morning after fasting. Serum leptin concentrations and additional markers of sepsis were compared between the sepsis group (n=128) and the non-sepsis group (n=203). Septic patients displayed significantly higher leptin serum concentrations compared with those of the non-sepsis group (mean concentration, 11.67 versus 4.824 mg/dl; P<0.001). The leptin levels in male patients were higher than those in female patients, particularly in the sepsis group. The accuracy of serum leptin levels in distinguishing septic patients from non-septic patients was 76%, and the area under the receiver operating characteristic (ROC) curve of serum leptin was ≤0.8. Additional markers of inflammation in the sepsis group were also significantly higher than those in the non-sepsis group. Positive correlations were identified between leptin and body temperature, heart rate and creatinine levels. Therefore, a prognostic model comprising a combination of leptin with temperature, platelet count, white blood cell count and heart rate was evaluated as an effective logistic regression model for the diagnosis of sepsis. The logistic regression output cut-off value was 0.46 and the area under the ROC curve was 0.953 (P<0.0001). It may be concluded that leptin is a valuable marker in the diagnosis of sepsis and the proposed prognostic model is an effective logistic regression model for the diagnosis of sepsis. The prognostic model is able to aid the differentiation of septic patients from non-septic patients.

The effects of perioperative probiotic treatment on serum zonulin concentration and subsequent postoperative infectious complications after colorectal cancer surgery: a double-center and double-blind randomized clinical trial

BACKGROUND

Zonulin is a newly discovered protein that has an important role in the regulation of intestinal permeability. Our previous study showed that probiotics can decrease the rate of infectious complications in patients undergoing colectomy for colorectal cancer.

OBJECTIVE

The objective was to determine the effects of the perioperative administration of probiotics on serum zonulin concentrations and the subsequent effect on postoperative infectious complications in patients undergoing colorectal surgery.

DESIGN

A total of 150 patients with colorectal carcinoma were randomly assigned to the control group (n = 75), which received placebo, or the probiotics group (n = 75). Both the probiotics and placebo were given orally for 6 d preoperatively and 10 d postoperatively. Outcomes were measured by assessing bacterial translocation, postoperative intestinal permeability, serum zonulin concentrations, duration of postoperative pyrexia, and cumulative duration of antibiotic therapy. The postoperative infection rate, the positive rate of blood microbial DNA, and the incidence of postoperative infectious complications-including septicemia, central line infection, pneumonia, urinary tract infection, and diarrhea-were also assessed.

RESULTS

The infection rate was lower in the probiotics group than in the control group (P < 0.05). Probiotics decreased the serum zonulin concentration (P < 0.001), duration of postoperative pyrexia, duration of antibiotic therapy, and rate of postoperative infectious complications (all P < 0.05). The p38 mitogen-activated protein kinase signaling pathway was inhibited by probiotics.

CONCLUSIONS

Perioperative probiotic treatment can reduce the rate of postoperative septicemia and is associated with reduced serum zonulin concentrations in patients undergoing colectomy. We propose a clinical regulatory model that might explain this association. This trial was registered at http://www.chictr.org/en/ as ChiCTR-TRC-00000423.