Long-term mortality and quality of life in sepsis: A systematic review*:

Structural changes of the heart during severe sepsis or septic shock

Cardiovascular dysfunction is common in severe sepsis or septic shock. Although functional alterations are often described, the elevated serum levels of cardiac proteins and autopsy findings of myocardial immune cell infiltration, edema, and damaged mitochondria suggest that structural changes to the heart during severe sepsis and septic shock may occur and may contribute to cardiac dysfunction. We explored the available literature on structural (versus functional) cardiac alterations during experimental and human endotoxemia and/or sepsis. Limited data suggest that the structural changes could be prevented, and myocardial function improved by (pre-)treatment with platelet-activating factor, cyclosporin A, glutamine, caffeine, simvastatin, or caspase inhibitors.

Hepatic Fibrosis in a Long-term Murine Model of Sepsis

Chronic sequelae of sepsis represent a major, yet underappreciated clinical problem, contributing to long-term mortality and quality-of-life impairment. In chronic liver disease, inflammation perpetuates fibrogenesis, but development of fibrosis in the post-acute phase of systemic inflammation has not been studied. Therefore, a mouse model of post-acute sequelae of sepsis was established based on polymicrobial peritonitis under antibiotic protection. Survival decreased to approximately 40% within 7 days and remained constant until day 28 (post-acute phase). In survivors, clinical recovery was observed within 1 week, whereas white blood cell and platelet count, as well as markers of liver injury, remained elevated until day 28. Macroscopically, inflammation and abscess formation were detected in the peritoneal space and on/in the liver. Microscopically, acute-chronic inflammation with ductular proliferation, focal granuloma formation in the parenchyma, and substantial hepatic fibrosis were observed. Increased numbers of potentially pathogenetic macrophages and α-smooth muscle actin-positive cells, presumably activated hepatic stellate cells, were detected in the vicinity of fibrotic areas. Fibrosis was associated with the presence of elastin and an augmented production/deposition of collagen types I and III. Microarray analyses revealed early activation of canonical and noncanonical pathways of hepatic stellate cell transdifferentiation. Thus, chronic sequelae of experimental sepsis were characterized by abscess formation, persistent inflammation, and substantial liver injury and fibrosis, the latter associated with increased numbers of macrophages/α-smooth muscle actin-positive cells and deposition of collagen types I and III. This suggests persistent activation of stellate cells, with consecutive fibrosis-a hallmark of chronic liver disease-as a result of acute life-threatening infection.

[Septic encephalopathy]

Septic encephalopathy describes a diffuse cerebral dysfunction in association with sepsis. It is the most common cause of altered brain function in the intensive care unit setting but other causes have to be excluded. Alterations in the level of consciousness occur early and are common. Epileptic seizures may occur but asymmetric neurological findings are not typical. The pathophysiology of septic encephalopathy is diverse and not fully elucidated; however, perfusion abnormalities play an important role. Neuropathological findings are diffuse, widespread and often show features of ischemia and non-bacterial inflammation. Diagnostic procedures should exclude frequent differential diagnoses, such as stroke, meningitis or encephalitis. Cerebral computed tomography (CT) is usually unremarkable but magnetic resonance imaging (MRI) may reveal vasogenic edema in terms of a posterior reversible encephalopathy syndrome. Septic encephalopathy requires an adequate therapy of the sepsis syndrome but a specific therapy is not yet available.

Genetics and genomics in pediatric septic shock

OBJECTIVES

Pediatric septic shock continues to be an important public health problem. Several investigative groups have applied genetic and genomic approaches as a means of identifying novel pathways and therapeutic targets, discovery of sepsis-related biomarkers, and identification of septic shock subclasses. This review will highlight studies in pediatric sepsis with a focus on gene association studies and genome-wide expression profiling.

DATA SOURCES

A summary of published literature involving gene association and expression profiling studies specifically involving pediatric sepsis and septic shock.

SUMMARY

Several polymorphisms of genes broadly involved in inflammation, immunity, and coagulation have been linked with susceptibility to sepsis, or outcome of sepsis in children. Many of these studies involve meningococcemia, and the strongest association involves a functional polymorphism of the plasminogen activator inhibitor-1 promoter region and meningococcal sepsis. Expression profiling studies in pediatric septic shock have identified zinc supplementation and inhibition of matrix metalloproteinase-8 activity as potential, novel therapeutic approaches in sepsis. Studies focused on discovery of sepsis-related biomarkers have identified interleukin-8 as a robust outcome biomarker in pediatric septic shock. Additional studies have demonstrated the feasibility and clinical relevance of gene expression-based subclassification of pediatric septic shock.

CONCLUSIONS

Pediatric sepsis and septic shock are increasingly being studied by genetic and genomic approaches and the accumulating data hold the promise of enhancing our future approach to this ongoing clinical problem.

Population burden of long-term survivorship after severe sepsis in older Americans

OBJECTIVES

To ascertain the absolute number of Medicare beneficiaries surviving at least 3 years after severe sepsis and to estimate their burden of cognitive dysfunction and disability.

DESIGN

Retrospective cohort analysis of Medicare data.

SETTING

All short-stay inpatient hospitals in the United States, 1996 to 2008.

PARTICIPANTS

Individuals aged 65 and older.

MEASUREMENTS

Severe sepsis was detected using a standard administrative definition. Case-fatality, prevalence, and incidence rates were calculated.

RESULTS

Six hundred thirty-seven thousand eight hundred sixty-seven Medicare beneficiaries were alive at the end of 2008 who had survived severe sepsis 3 or more years earlier. An estimated 476,862 (95% confidence interval (CI) = 455,026-498,698) had functional disability, with 106,311 (95% CI = 79,692-133,930) survivors having moderate to severe cognitive impairment. The annual number of new 3-year survivors after severe sepsis rose 119% during 1998 to 2008. The increase in survivorship resulted from more new diagnoses of severe sepsis rather than a change in case-fatality rates; severe sepsis rates rose from 13.0 per 1,000 Medicare beneficiary-years to 25.8 (P < .001), whereas 3-year case fatality rates changed much less, from 73.5% to 71.3% (P < .001) for the same cohort. Increasing rates of organ dysfunction in hospitalized individuals drove the increase in severe sepsis incidence, with an additional small contribution from population aging.

CONCLUSIONS

Sepsis survivorship, which has substantial long-term morbidity, is a common and rapidly growing public health problem for older Americans. There has been little change in long-term case-fatality, despite changes in practice. Clinicians should anticipate more-frequent sequelae of severe sepsis in their patient populations.

Health-related quality of life: implications for critical care interventional studies and why we need to collaborate with patients

PURPOSE OF REVIEW

Health-related quality of life (HRQoL) is an important patient-reported outcome measure following critical illness. 'Validated' and professionally endorsed generic measures are widely used to evaluate critical care intervention and guide practice, policy and research. Although recognizing that they are 'here to stay', leading QoL researchers are beginning to question their 'fitness for purpose'. It is therefore timely to review critiques of their limitations in the wider healthcare and social science literatures and to examine the implications for critical care research including, in particular, emerging interventional studies in which HRQoL is the primary outcome of interest.

RECENT FINDINGS

Generic HRQoL measures have provided important yet limited insights into HRQoL among survivors of critical illness. They are rarely developed or validated in collaboration with patients and cannot therefore be assumed to reflect their experiences and perspectives.

SUMMARY

Collaboration with patients is advocated in order to improve the interpretation and utility of such data. Failure to do so may result in important study effects being overlooked and the dismissal of potentially useful interventions.

Spurious inferences about long-term outcomes: the case of severe sepsis and geriatric conditions

RATIONALE

Survivors of critical illness suffer significant limitations and disabilities.

OBJECTIVES

Ascertain whether severe sepsis is associated with increased risk of so-called geriatric conditions (injurious falls, low body mass index [BMI], incontinence, vision loss, hearing loss, and chronic pain) and whether this association is measured consistently across three different study designs.

METHODS

Patients with severe sepsis were identified in the Health and Retirement Study, a nationally representative cohort interviewed every 2 years, 1998 to 2006, and in linked Medicare claims. Three comparators were used to assess an association of severe sepsis with geriatric conditions in survivors: the prevalence in the United States population aged 65 years and older, survivors' own pre-sepsis levels assessed before hospitalization, or survivors' own pre-sepsis trajectory.

MEASUREMENTS AND MAIN RESULTS

Six hundred twenty-three severe sepsis hospitalizations were followed a median of 0.92 years. When compared with the 65 years and older population, surviving severe sepsis was associated with increased rates of low BMI, injurious falls, incontinence, and vision loss. Results were similar when comparing survivors to their own pre-sepsis levels. The association of low BMI and severe sepsis persisted when controlling for patients' pre-sepsis trajectories, but there was no association of severe sepsis with injurious falls, incontinence, vision loss, hearing loss, and chronic pain after such controls.

CONCLUSIONS

Geriatric conditions are common after severe sepsis. However, severe sepsis is associated with increased rates of only a subset of geriatric conditions, not all. In studying outcomes after acute illness, failing to measure and control for both preillness levels and trajectories may result in erroneous conclusions.

Gu-4 suppresses affinity and avidity modulation of CD11b and improves the outcome of mice with endotoxemia and sepsis

Background

Systemic leukocyte activation and disseminated leukocyte adhesion will impair the microcirculation and cause severe decrements in tissue perfusion and organ function in the process of severe sepsis. Gu-4, a lactosyl derivative, could selectively target CD11b to exert therapeutic effect in a rat model of severe burn shock. Here, we addressed whether Gu-4 could render protective effects on septic animals.

Methodology/Principal Findings

On a murine model of endotoxemia induced by lipopolysaccharide (LPS), we found that the median effective dose (ED50) of Gu-4 was 0.929 mg/kg. In vivo treatment of Gu-4 after LPS challenge prominently attenuated LPS-induced lung injury and decreased lactic acid level in lung tissue. Using the ED50 of Gu-4, we also demonstrated that Gu-4 treatment significantly improved the survival rate of animals underwent sepsis induced by cecal ligation and puncture. By adhesion and transwell migration assays, we found that Gu-4 treatment inhibited the adhesion and transendothelial migration of LPS-stimulated THP-1 cells. By flow cytometry and microscopy, we demonstrated that Gu-4 treatment inhibited the exposure of active I-domain and the cluster formation of CD11b on the LPS-stimulated polymorphonuclear leukocytes. Western blot analyses further revealed that Gu-4 treatment markedly inhibited the activation of spleen tyrosine kinase in LPS-stimulated THP-1 cells.

Conclusions/Significance

Gu-4 improves the survival of mice underwent endotoxemia and sepsis, our in vitro investigations indicate that the possible underlying mechanism might involve the modulations of the affinity and avidity of CD11b on the leukocyte. Our findings shed light on the potential use of Gu-4, an interacting compound to CD11b, in the treatment of sepsis and septic shock.

Long-term outcome of invasive Staphylococcus aureus infections

BACKGROUND

Short-term mortality from invasive Staphylococcus aureus infections (ISA) is high. Death rates from 20% to 60% are reported. Long-term outcome has not been investigated. Studies of other critical illnesses have demonstrated incremental health effects that persist after hospital discharge. Several researchers have proposed that evaluation of mortality secondary to sepsis should take place after 1 y.

METHODS

We performed an observational, prospective, population-based study of long-term mortality and recurrence in a cohort of ISA patients during 2 y.

RESULTS

One hundred and fifty-seven patients were included. All-cause mortality after 1 y was 37.6% and after 3 y was 45.5%. The multivariate survival analysis explored different independent factors for short-term compared to long-term mortality. Age, comorbidity, and place of acquisition were the determinants of long-term outcome. In contrast, infection-related factors such as disease severity and systolic blood pressure determined short-term mortality. The relapse-reinfection rate was 11.2% (16 in 143 episodes in 127 patients living 4 weeks after inclusion). Predictive factors for relapse-reinfection in a univariate analysis were joint prosthesis (28.6%, p = 0.027), haemodialysis (27.8%, p = 0.017), kidney disease (22.2%, p = 0.015), and healthcare- and nosocomial-related infection (18.3%, p = 0.029). No association to length of antibiotic therapy and relapse-reinfection rate was observed, nor any sex differences. The majority of relapses-reinfections (11 of 16) occurred during the first 11 months after the initial episode.

CONCLUSION

Patients with ISA infections, irrespective of age, suffer a high long-term mortality and recurrence rate.

Acute cervico-facial infection in Scotland 2010: patterns of presentation, patient demographics and recording of systemic involvement

Acute bacterial cervicofacial infection is a common problem that is most often secondary to dental infection. Most cases present as localised abscesses but some may be associated with serious morbidity including scarring, embarrassment of the airway, SIRS (systemic inflammatory response syndrome), and sepsis syndrome. Fourteen oral surgery or maxillofacial surgery units in Scotland took part in a clinical audit of acute infection during two four-week cycles (August and November) in 2010. Information regarding the patients, signs and symptoms, and management was recorded. Training material was distributed between cycles with information on SIRS, sepsis, and the prescription of antibiotics. Overall, 140 patients presented with acute infection. There was an equal sex distribution and ages ranged from 5 to 87 years. There was an association with deprivation and 36% of patients were from the lowest socioeconomic quintile. Most infections were dental (n=120, 86%), and patients presented with pain and swelling (n=120, 86% and n=134, 96%, respectively) Twenty-three patients (16%) met the criteria for SIRS. A further 23 (16%) had at least one positive SIRS marker with incomplete recording of the remaining markers. Twenty-six patients (19%) had no recorded SIRS markers. Cervicofacial infection can be associated with serious morbidity and mortality, which may be better managed if the systemic signs and symptoms of sepsis are recognised and recorded at presentation. This study showed that the recording of signs of sepsis was variable even with training. Further training of junior staff to recognise severe acute bacterial infection may improve management.

Hospital and long-term outcomes of ICU-treated severe community- and hospital-acquired, and ventilator-associated pneumonia patients

BACKGROUND

Our purpose was to analyse the association of pneumonia types with hospital and long-term outcomes of intensive care unit (ICU)-treated pneumonia patients.

METHODS

The occurrence of pneumonia was retrospectively evaluated among prospectively registered patients admitted into a mixed university-level ICU during a 14-month period. Their age, severity of underlying disease, malignancy, immunosuppressive therapy and organ dysfunctions were recorded, as well as the length of hospital stay and short- and long-term mortalities.

RESULTS

There were 117 severe community-acquired pneumonia (SCAP), 66 hospital-acquired pneumonia (HAP) and 25 ventilator-associated pneumonia (VAP) cases among the 817 patients admitted. ICU and hospital mortality did not differ between pneumonia groups. VAP and HAP patients had more malignant underlying diseases than SCAP patients (P < 0.001). HAP patients were older than SCAP and VAP patients (P = 0.023). The admission Acute Physiology and Chronic Health Evaluation II scores did not differ between the groups (P > 0.90). The patients with VAP had higher Sequential Organ Failure Assessment maximum scores compared with patients with SCAP and HAP (P < 0.001). In an adjusted multivariate logistic regression model, there were no significant differences in odds ratios for hospital mortality between the three pneumonia types. Mortality among the hospital survivors during the 12-month follow-up period was 18% (16/89) in the SCAP group, 35% (18/51) in the HAP group and 41% (7/17) in the VAP group (P = 0.023).

CONCLUSION

The type of pneumonia (i.e. SCAP, HAP or VAP) had no significant association with hospital mortality, whereas the SCAP patients had the lowest 1-year mortality.

Comparison of Predisposition, Insult/Infection, Response, and Organ dysfunction, Acute Physiology And Chronic Health Evaluation II, and Mortality in Emergency Department Sepsis in patients meeting criteria for early goal-directed therapy and the severe sepsis resuscitation bundle

PURPOSE

The aim of the study was to examine the performance of the Predisposition, Insult/Infection, Response, and Organ dysfunction (PIRO) model compared with the Acute Physiology and Chronic Health Evaluation (APACHE) II and Mortality in Emergency Department Sepsis (MEDS) scoring systems in predicting in-hospital mortality for patients presenting to the emergency department (ED) with severe sepsis or septic shock.

MATERIALS AND METHODS

This study was an analysis of a prospectively maintained registry including adult patients with severe sepsis or septic shock meeting criteria for early goal-directed therapy and the severe sepsis resuscitation bundle over a 6-year period. The registry contains data on patient demographics, sepsis category, vital signs, laboratory values, ED length of stay, hospital length of stay, physiologic scores, and outcome status. The discrimination and calibration characteristics of PIRO, APACHE II, and MEDS were analyzed.

RESULTS

Five-hundred forty-one patients with age 63.5 ± 18.5 years were enrolled, 61.9% in septic shock, 46.9% blood-culture positive, and 31.8% in-hospital mortality. Median (25th and 75th percentile) PIRO, APACHE II, and MEDS scores were 6 (5 and 8), 28 (22 and 34), and 12 (9 and 15), with predicted mortalities of 48.5% (40.1 and 63.9), 66.0% (42.0 and 83.0), and 16.0% (9.0 and 39.0), respectively. The area under the receiver operating characteristic curves for PIRO was 0.71 (95% confidence interval, 0.66-0.75); APACHE II, 0.71 (0.66-0.76); and MEDS, 0.63 (0.60-0.70). The standardized mortality ratio was 0.70 (0.08-1.41), 0.70 (-0.46 to 1.80), and 4.00 (-8.53 to 16.62), respectively. Actual mortality significantly increased with increasing PIRO score in patients with APACHE II 25 or more (P < .01).

CONCLUSIONS

The PIRO, APACHE II, and MEDS have variable abilities to early discriminate and estimate in-hospital mortality of patients presenting to the ED meeting criteria for early goal-directed therapy and the severe sepsis resuscitation bundle. The PIRO may provide additional risk stratification in patients with APACHE II 25 or more. More studies are required to evaluate the clinical applicability of PIRO in high-risk patients with severe sepsis and septic shock.

Self-reported depressive symptoms and memory complaints in survivors five years after ARDS

BACKGROUND

Survivors of ARDS report depressive symptoms and memory complaints, the prevalence of which after 5 years is unknown.

METHODS

We administered instruments assessing symptoms of depression (Beck Depression Inventory II [BDI-II]) and memory complaints (Memory Assessment Clinics Self-Rating Scale [MAC-S]) to 64 survivors of ARDS from four university-affiliated ICUs 5 years after ICU discharge. We compared BDI-II scores to quality of life (Medical Outcomes Study 36-Item Short Form [SF-36]) mental health domains (role emotional, mental health, mental component summary), compared BDI-II and MAC-S scores to earlier scores (median, 22 months postdischarge), and examined return to work.

RESULTS

Forty-three (67.2%), 46 (71.9%), and 38 (59.4%) patients fully completed the BDI-II, MAC-S ability subscale, and MAC-S frequency of occurrence subscale, respectively. Responders were young (median, 48 years; first-third quartile [Q1-Q3], 39-61 years) with high illness severity. The median BDI-II score was 10 (Q1-Q3, 3-18); eight of 43 (18.6%) had moderate to severe depressive symptoms compared with 14 of 43 (32.6%) earlier (P = .15, n = 38 with paired data). Median MAC-S ability and MAC-S frequency scores were 81 (Q1-Q3, 57-92) and 91.5 (Q1-Q3, 76-105), respectively, similar to earlier scores (P = .67 and P = .64, respectively); 0% to 4.3% scored > 2 SDs below population norms. Higher BDI-II score was predicted by higher earlier BDI-II score, slower recovery of organ function, and longer duration of mechanical ventilation and ICU stay. Higher MAC-S score was predicted by higher earlier MAC-S score. SF-36 mental health domain scores were very stable (P = .57-.83). BDI-II and SF-36 mental health domains were negatively correlated (Spearman coefficient, -0.50 to -0.82). Most patients returned to work regardless of depressive symptoms (minimal to mild, 31 of 35 [88.6%]; moderate to severe, five of eight [62.5%]; P = .12).

CONCLUSIONS

Compared with ∼ 2 years postdischarge from the ICU, depressive symptoms and memory complaints were similar at 5 years. Mental health domains of the SF-36 may not be sensitive to small changes in mood symptoms.

The potential contributions of lethal and edema toxins to the pathogenesis of anthrax associated shock

Outbreaks of Bacillus anthracis in the US and Europe over the past 10 years have emphasized the health threat this lethal bacteria poses even for developed parts of the world. In contrast to cutaneous anthrax, inhalational disease in the US during the 2001 outbreaks and the newly identified injectional drug use form of disease in the UK and Germany have been associated with relatively high mortality rates. One notable aspect of these cases has been the difficulty in supporting patients once shock has developed. Anthrax bacilli produce several different components which likely contribute to this shock. Growing evidence indicates that both major anthrax toxins may produce substantial cardiovascular dysfunction. Lethal toxin (LT) can alter peripheral vascular function; it also has direct myocardial depressant effects. Edema toxin (ET) may have even more pronounced peripheral vascular effects than LT, including the ability to interfere with the actions of conventional vasopressors. Additionally, ET also appears capable of interfering with renal sodium and water retention. Importantly, the two toxins exert their actions via quite different mechanisms and therefore have the potential to worsen shock and outcome in an additive fashion. Finally, both toxins have the ability to inhibit host defense and microbial clearance, possibly contributing to the very high bacterial loads noted in patients dying with anthrax. This last point is clinically relevant since emerging data has begun to implicate other bacterial components such as anthrax cell wall in the shock and organ injury observed with infection. Taken together, accumulating evidence regarding the potential contribution of LT and ET to anthrax-associated shock supports efforts to develop adjunctive therapies that target both toxins in patients with progressive shock.

Effects of a potent peroxynitrite decomposition catalyst in murine models of endotoxemia and sepsis

Excessive free-radical production due to various bacterial components released during bacterial infection has been linked to cell death and tissue injury. Peroxynitrite is a highly reactive oxidant produced by the combination of nitric oxide (NO) and superoxide anion, which has been implicated in cell death and tissue injury in various forms of critical illness. Pharmacological decomposition of peroxynitrite may represent a potential therapeutic approach in diseases associated with the overproduction of NO and superoxide. In the present study, we tested the effect of a potent peroxynitrite decomposition catalyst in murine models of endotoxemia and sepsis. Mice were injected i.p. with LPS 40 mg/kg with or without FP15 [Fe(III) tetrakis-2-(N-triethylene glycol monomethyl ether)pyridyl porphyrin] (0.1, 0.3, 1, 3, or 10 mg/kg per hour). Mice were killed 12 h later, followed by the harvesting of samples from the lung, liver, and gut for malondialdehyde and myeloperoxidase measurements. In other subsets of animals, blood samples were obtained by cardiac puncture at 1.5, 4, and 8 h after LPS administration for cytokine (TNF-α, IL-1β, and IL-10), nitrite/nitrate, alanine aminotransferase, and blood urea nitrogen measurements. Endotoxemic animals showed an increase in survival from 25% to 80% at the FP15 doses of 0.3 and 1 mg/kg per hour. The same dose of FP15 had no effect on plasma levels of nitrite/nitrate. There was a reduction in liver and lung malondialdehyde in the endotoxemic animals pretreated with FP15, as well as in hepatic myeloperoxidase and biochemical markers of liver and kidney damage (alanine aminotransferase and blood urea nitrogen). In a bacterial model of sepsis induced by cecal ligation and puncture, FP15 treatment (0.3 mg/kg per day) significantly protected against mortality. The current data support the view that peroxynitrite is a critical factor mediating liver, gut, and lung injury in endotoxemia and septic shock: its pharmacological neutralization may be of therapeutic benefit.

The epidemiology of sepsis in general surgery patients

BACKGROUND

Sepsis is increasing in hospitalized patients. Our purpose is to describe its current epidemiology in a general surgery (GS) intensive care unit (ICU) where patients are routinely screened and aggressively treated for sepsis by an established protocol.

METHODS

Our prospective, Institutional Review Board-approved sepsis research database was queried for demographics, biomarkers reflecting organ dysfunction, and mortality. Patients were grouped as sepsis, severe sepsis, or septic shock using refined consensus criteria. Data are compared by analysis of variance, Student's t test, and χ test (p<0.05 significant).

RESULTS

During 24 months ending September 2009, 231 patients (aged 59 years ± 3 years; 43% men) were treated for sepsis. The abdomen was the source of infection in 69% of patients. Several baseline biomarkers of organ dysfunction (BOD) correlated with sepsis severity including lactate, creatinine, international normalized ratio, platelet count, and d-dimer. Direct correlation with mortality was noted with particular baseline BODs including beta natriuretic peptide, international normalized ratio, platelet count, aspartate transaminase, alanine aminotransferase, and total bilirubin. Most patients present with severe sepsis (56%) or septic shock (26%) each with increasing multiple BODs. Septic shock has prohibitive mortality rate (36%), and those who survive septic shock have prolonged ICU stays.

CONCLUSION

In general surgery ICU patients, sepsis is predominantly caused by intra-abdominal infection. Multiple BODs are present in severe sepsis and septic shock but are notably advanced in septic shock. Despite aggressive sepsis screening and treatment, septic shock remains a morbid condition.

Health-related quality of life in Australian survivors of critical illness

OBJECTIVE

To document health-related quality of life of an Australian sample of intensive care unit survivors 6 months after intensive care unit discharge and compare this with preadmission health-related quality of life, health-related quality of life of national population norms, and international samples of intensive care unit survivors.

DESIGN

Prospective observational single-center study.

SETTING

Eighteen-bed medical-surgical tertiary intensive care unit of an Australian metropolitan hospital.

PATIENTS

Of the 122 eligible patients, 100 were recruited (intensive care unit length of stay >48 hrs, age >18 yrs, not imminently at risk of death) and the final sample comprised 67 patients, age (median [interquartile range], 61 yrs [49-73 yrs]), 60% male admitted to the intensive care unit for a median [interquartile range] 101 hrs (68-149 hrs). Normative age- and sex-matched Australian Short-Form 36 data from the Australian Bureau of Statistics, selected international cohorts of intensive care unit survivors, and their respective national age-matched normative data were included for comparison.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Sixty-seven participants provided responses to questions rating health-related quality of life (Australian Short-Form 36) at preadmission (on admission to the intensive care unit or through retrospective recall as soon as able) and 6 months after intensive care unit discharge. Ten additional participants were unable to provide study data without proxy input and were excluded from analysis. Participants reported clinically meaningful improvements in bodily pain (p = .001), social functioning (p = .03), role-emotional domains of the Short-Form 36 (p = .04), and mental component summary score (p = .01) at 6 months after intensive care unit discharge, mostly attributable to the patients undergoing cardiac surgery, whereas remaining Short-Form 36 domains showed no difference between preadmission and 6 months (p > .05). Participants reported clinically meaningful decrements in preadmission Short-Form 36 data compared with the Australian normative population with role-physical (p < .001) and physical functioning (p < .001) most affected at follow-up. Health-related quality of life in this sample was comparable with international samples of intensive care unit survivors.

CONCLUSIONS

Although the majority of health-related quality of life domains did not differ between preadmission and 6-month follow-up, participants reported significant and clinically meaningful improvements in pain and mental health at follow-up. Critical illness survivors' health-related quality of life remained within 1 sd of Australian norms at follow-up and physical function health-related quality of life was most affected. Health-related quality of life in these Australian survivors of the intensive care unit was comparable with international survivors 6 months after intensive care unit admission.

A unique finding on gallium-67 scintigraphy: widespread fatal skin manifestations of Pseudomonas sepsis

We report a case of a 25-year-old woman presented with neutropenic fever after chemotherapy for the relapse of acute biphenotypic leukemia. Gallium-67 scintigraphy for the detection of infectious foci demonstrated a unique pattern of numerous foci with intense and varying-sized radioactivity spreading throughout the body. The subsequent skin biopsy and culture proved Pseudomonas infection. Therefore, this unique image, in combination with clinical information, was compatible with cutaneous manifestations of Pseudomonas sepsis. Eventually, the patient died of uncontrolled systemic infection despite the aggressive antibiotic treatment. This case reminded clinicians and nuclear medicine physicians to notice the potentially fatal finding on gallium-67 scan.

Heme oxygenase-1 couples activation of mitochondrial biogenesis to anti-inflammatory cytokine expression

The induction of heme oxygenase-1 (HO-1; Hmox1) by inflammation, for instance in sepsis, is associated both with an anti-inflammatory response and with mitochondrial biogenesis. Here, we tested the idea that HO-1, acting through the Nfe2l2 (Nrf2) transcription factor, links anti-inflammatory cytokine expression to activation of mitochondrial biogenesis. HO-1 induction after LPS stimulated anti-inflammatory IL-10 and IL-1 receptor antagonist (IL-1Ra) expression in mouse liver, human HepG2 cells, and mouse J774.1 macrophages but blunted tumor necrosis factor-α expression. This was accompanied by nuclear Nfe2l2 accumulation and led us to identify abundant Nfe2l2 and other mitochondrial biogenesis transcription factor binding sites in the promoter regions of IL10 and IL1Ra compared with pro-inflammatory genes regulated by NF-κΒ. Mechanistically, HO-1, through its CO product, enabled these transcription factors to bind the core IL10 and IL1Ra promoters, which for IL10 included Nfe2l2, nuclear respiratory factor (NRF)-2 (Gabpa), and MEF2, and for IL1Ra, included NRF-1 and MEF2. In cells, Hmox1 or Nfe2l2 RNA silencing prevented IL-10 and IL-1Ra up-regulation, and HO-1 induction failed post-LPS in Nfe2l2-silenced cells and post-sepsis in Nfe2l2(-/-) mice. Nfe2l2(-/-) mice compared with WT mice, showed more liver damage, higher mortality, and ineffective CO rescue in sepsis. Nfe2l2(-/-) mice in sepsis also generated higher hepatic TNF-α mRNA levels, lower NRF-1 and PGC-1α mRNA levels, and no enhancement of anti-inflammatory Il10, Socs3, or bcl-x(L) gene expression. These findings disclose a highly structured transcriptional network that couples mitochondrial biogenesis to counter-inflammation with major implications for immune suppression in sepsis.

Lack of effect of oral administration of resveratrol in LPS-induced systemic inflammation

PURPOSE

The high mortality index due to sepsis and the lack of an effective treatment requires the search for new compounds that can serve as therapy for this disease. Resveratrol, a well-known anti-inflammatory natural compound, might be a good candidate for the treatment of sepsis. The aim of this work was to study the effects of oral administration of resveratrol, before and after sepsis initiation, on inflammation markers in a murine model of endotoxin-induced sepsis.

METHODS

Sprague-Dawley male rats were treated with resveratrol the 3 days prior to LPS administration and 45 min later. Hematological parameters, TNF-α, IL-1β and CINC-1, FRAP and TBARS levels were determined. Resveratrol and resveratrol-derived metabolites profile in plasma was compared after oral and intraperitoneal administration.

RESULTS

Oral treatment with resveratrol had no apparent systemic protective effects. However, resveratrol reduced the levels of lipid peroxidation in the small intestine and colon. Importantly, the administration of LPS caused a decrease in resveratrol absorption. When resveratrol bioavailability after i.p. administration was compared to that observed after oral administration, a different profile of resveratrol metabolites was found in plasma.

CONCLUSION

These results highlight the importance of studying the bioavailability of the assayed compounds in the experimental models used to be able to choose the best route of administration depending on the target organ and to determine which compounds or derived metabolites are effective treating the studied disease.

What is the pathophysiology of the septic host upon admission?

The enormous case-fatality rate of severe sepsis and septic shock has resulted in considerable efforts being made towards understanding their complex mechanisms of pathogenesis. This has been done with the hope that agents that interfere with the pathways of pathogenesis and modulate the immune response of the host may be candidates for therapy. Disappointing results from most trials of immunomodulators in sepsis have led to understanding that the progression of patients to multiple organ dysfunction syndrome involves blunting of the pro-inflammatory cytokine storm. Instead, the compensatory anti-inflammatory response syndrome (CARS) develops, which is characterised by immunoparalysis. Components of this syndrome are impaired phagocytosis by neutrophils, decreased expression of HLA-DR on monocytes, impairment of ex vivo cytokine stimulation of monocytes, CD4 lymphopenia due to apoptosis of lymphocytes and predominance of anti-inflammatory T(h)2 and regulatory T-cell responses over pro-inflammatory T(h)1 and T(17) responses. CARS is not the sole explanation for the failure of trials of immunomodulators in sepsis. Recent data from the Hellenic Sepsis Study Group demonstrate that components of CARS upon transition from sepsis to severe sepsis/shock differ in relation to the underlying type of infection. These data underscore that the pathogenesis of sepsis presents considerable heterogeneity from one patient to another. That heterogeneity should be taken into consideration when deciding to administer an immunomodulator.

An increase in exhaled CO concentration in systemic inflammation/sepsis

Despite recent progress in Critical Care Medicine, sepsis is still a major medical problem with a high rate of mortality and morbidity especially in intensive care units. Oxidative stress induced by inflammation associated with sepsis causes degradation of heme protein, increases microsomal free heme content, promotes further oxidative stress and results in cellular and organ damage. Heme-oxygenase-1 (HO-1) is a rate-limiting enzyme for heme breakdown. HO-1 breaks down heme to yield CO, iron and biliverdin. Measurement of CO in exhaled air may potentially be useful in monitoring changes in HO enzyme activity in vivo, which might reflect the degree of inflammation or oxidative stress in patients with systemic inflammation. The increased exhaled CO concentrations were observed after anesthesia/surgery, in critically ill patients and also in systemic inflammation/sepsis. Some reports also showed that exhaled CO concentration is related to mortality. Further studies are needed to elucidate whether increased endogenous CO production may predict a patient's morbidity and mortality. Techniques for monitoring CO are continuously being refined and this technique may find its way into the office of clinicians.

Long-term cognitive impairment and functional disability among survivors of severe sepsis

CONTEXT

Cognitive impairment and functional disability are major determinants of caregiving needs and societal health care costs. Although the incidence of severe sepsis is high and increasing, the magnitude of patients' long-term cognitive and functional limitations after sepsis is unknown.

OBJECTIVE

To determine the change in cognitive impairment and physical functioning among patients who survive severe sepsis, controlling for their presepsis functioning.

DESIGN, SETTING, AND PATIENTS

A prospective cohort involving 1194 patients with 1520 hospitalizations for severe sepsis drawn from the Health and Retirement Study, a nationally representative survey of US residents (1998-2006). A total of 9223 respondents had a baseline cognitive and functional assessment and had linked Medicare claims; 516 survived severe sepsis and 4517 survived a nonsepsis hospitalization to at least 1 follow-up survey and are included in the analysis.

MAIN OUTCOME MEASURES

Personal interviews were conducted with respondents or proxies using validated surveys to assess the presence of cognitive impairment and to determine the number of activities of daily living (ADLs) and instrumental ADLs (IADLs) for which patients needed assistance.

RESULTS

Survivors' mean age at hospitalization was 76.9 years. The prevalence of moderate to severe cognitive impairment increased 10.6 percentage points among patients who survived severe sepsis, an odds ratio (OR) of 3.34 (95% confidence interval [CI], 1.53-7.25) in multivariable regression. Likewise, a high rate of new functional limitations was seen following sepsis: in those with no limits before sepsis, a mean 1.57 new limitations (95% CI, 0.99-2.15); and for those with mild to moderate limitations before sepsis, a mean of 1.50 new limitations (95% CI, 0.87-2.12). In contrast, nonsepsis general hospitalizations were associated with no change in moderate to severe cognitive impairment (OR, 1.15; 95% CI, 0.80-1.67; P for difference vs sepsis = .01) and with the development of fewer new limitations (mean among those with no limits before hospitalization, 0.48; 95% CI, 0.39-0.57; P for difference vs sepsis <.001 and mean among those with mild to moderate limits, 0.43; 95% CI, 0.23-0.63; P for difference = .001). The declines in cognitive and physical function persisted for at least 8 years.

CONCLUSIONS

Severe sepsis in this older population was independently associated with substantial and persistent new cognitive impairment and functional disability among survivors. The magnitude of these new deficits was large, likely resulting in a pivotal downturn in patients' ability to live independently.