Efficacy of therapy with recombinant human activated protein C of critically ill surgical patients with infection complicated by septic shock and multiple organ dysfunction syndrome

Efficacy and safety of low-molecular-weight heparin in patients with sepsis: a meta-analysis of randomized controlled trials

Low-molecular-weight heparin (LMWH) is part of standard supportive care. We conducted a meta-analysis to investigate the efficacy and safety of LMWH in septic patients. We searched Pubmed, Embase, CKNI and Wanfang database prior to July 2015 for randomized controlled trials investigating treatment with LMWH in septic patients. We identified 11 trials involving 594 septic patients. Meta-analysis showed that LMWH significantly reduced prothrombin time (mean differences [MD] −0.88; 95% CI −1.47 to −0.29), APACHE II score (MD −2.50; 95% CI −3.55 to −1.46), and 28-day mortality (risk ratio [RR] 0.72; 95% CI 0.57–0.91) as well as increased the platelet counts (MD 18.33; 95% CI 0.73–35.93) than the usual treatment. However, LMWH did not reduce D-dimer (MD −0.34; 95% CI −0.85 to 0.18). LMWH also significantly increased the bleeding events (RR 3.82; 95% CI 1.81–8.08). LMWH appears to reduce 28-day mortality and APACHE II score among septic patients. Bleeding complications should be monitored during the LMWH treatment. As for limited data about LMWH and sepsis in the English literature, only trials published in the Chinese were included in the meta-analysis.

Low-dose heparin as treatment for early disseminated intravascular coagulation during sepsis: A prospective clinical study

The present study aimed to investigate whether low-dose heparin improves the condition of patients suffering from early disseminated intravascular coagulation (pre-DIC) during sepsis. In total, 37 patients were randomly divided into low-dose heparin intervention and control groups. The heparin group received a low-dose of heparin for 5–7 days, while the other group received only saline. The two groups were treated for sepsis. Blood samples were collected at various times and acute physiology and chronic health evaluation (APACHE)-II scores were recorded at day 1 and 7. In addition, the number of days applying mechanical ventilation and in the intensive care unit (ICU) were recorded, as well as the 28-day mortality rate. APACHE-II scores in the two groups decreased following treatment, however, scores in the heparin group decreased more significantly. Prothrombin fragment and thrombin-antithrombin complex levels in the heparin group were significantly decreased. In addition, the number of days applying a ventilator was fewer and the total stay in ICU was significantly shorter compared with the control group. Significantly fewer complications were observed in the heparin group, however, there was no significant difference in the 28-day mortality rate. In conclusion, low-dose heparin improves the hypercoagulable state of sepsis, which subsequently reduces the incidence of DIC or multiple organ dysfunction syndrome, decreasing the number of days of mechanical ventilation and hospitalization.

Protein C and acute inflammation: a clinical and biological perspective

The protein C system plays an active role in modulating severe systemic inflammatory processes such as sepsis, trauma, and acute respiratory distress syndrome (ARDS) via its anticoagulant and anti-inflammatory properties. Plasma levels of activated protein C (aPC) are lower than normal in acute inflammation in humans, except early after severe trauma when high plasma levels of aPC may play a mechanistic role in the development of posttraumatic coagulopathy. Thus, following positive results of preclinical studies, a clinical trial (PROWESS) with high continuous doses of recombinant human aPC given for 4 days demonstrated a survival benefit in patients with severe sepsis. This result was not confirmed by subsequent clinical trials, including the recently published PROWESS-SHOCK trial in patients with septic shock and a phase II trial with patients with nonseptic ARDS. A possible explanation for the major difference in outcome between PROWESS and PROWESS-SHOCK trials is that lung-protective ventilation was used for the patients included in the recent PROWESS-SHOCK, but not in the original PROWESS trial. Since up to 75% of sepsis originates from the lung, aPC treatment may not have added enough to the beneficial effect of lung-protective ventilation to show lower mortality. Thus whether aPC will continue to be used to modulate the acute inflammatory response in humans remains uncertain. Because recombinant human aPC has been withdrawn from the market, a better understanding of the complex interactions between coagulation and inflammation is needed before considering the development of new drugs that modulate both coagulation and acute inflammation in humans.

Human recombinant protein C for severe sepsis and septic shock in adult and paediatric patients

BACKGROUND

Sepsis is a common and frequently fatal condition. Human recombinant activated protein C (APC) has been introduced to reduce the high risk of death associated with severe sepsis or septic shock. This systematic review is an update of a Cochrane review originally published in 2007.

OBJECTIVES

We assessed the benefits and harms of APC for patients with severe sepsis or septic shock.

SEARCH METHODS

We searched CENTRAL (The Cochrane Library 2012, Issue 6); MEDLINE (2010 to June 2012); EMBASE (2010 to June 2012); BIOSIS (1965 to June 2012); CINAHL (1982 to June 2012) and LILACS (1982 to June 2012). There was no language restriction.

SELECTION CRITERIA

We included randomized clinical trials assessing the effects of APC for severe sepsis or septic shock in adults and children. We excluded studies on neonates. We considered all-cause mortality at day 28 and at the end of study follow up, and hospital mortality as the primary outcomes.

DATA COLLECTION AND ANALYSIS

We independently performed trial selection, risk of bias assessment, and data extraction in duplicate. We estimated relative risks (RR) for dichotomous outcomes. We measured statistical heterogeneity using the I(2) statistic. We used a random-effects model.

MAIN RESULTS

We identified one new randomized clinical trial in this update which includes six randomized clinical trials involving 6781 participants in total, five randomized clinical trials in adult (N = 6307) and one randomized clinical trial in paediatric (N = 474) participants. All trials had high risk of bias and were sponsored by the pharmaceutical industry. APC compared with placebo did not significantly affect all-cause mortality at day 28 compared with placebo (780/3435 (22.7%) versus 767/3346 (22.9%); RR 1.00, 95% confidence interval (CI) 0.86 to 1.16; I(2) = 56%). APC did not significantly affect in-hospital mortality (393/1767 (22.2%) versus 379/1710 (22.1%); RR 1.01, 95% CI 0.87 to 1.16; I(2) = 20%). APC was associated with an increased risk of serious bleeding (113/3424 (3.3%) versus 74/3343 (2.2%); RR 1.45, 95% CI 1.08 to 1.94; I(2) = 0%). APC did not significantly affect serious adverse events (463/3334 (13.9%) versus 439/3302 (13.2%); RR 1.04, 95% CI 0.92 to 1.18; I(2) = 0%). Trial sequential analyses showed that more trials do not seem to be needed for reliable conclusions regarding these outcomes.

AUTHORS' CONCLUSIONS

This updated review found no evidence suggesting that APC should be used for treating patients with severe sepsis or septic shock. APC seems to be associated with a higher risk of bleeding. The drug company behind APC, Eli Lilly, has announced the discontinuation of all ongoing clinical trials using this drug for treating patients with severe sepsis or septic shock. APC should not be used for sepsis or septic shock outside randomized clinical trials.

The value of critical care

The primary focus of this review is on the cost-effectiveness of critical care. The rapid growth in health care expenditures has engendered careful scrutiny of the practice of medicine with regard not only to effectiveness but also to efficiency. This shift necessitates that physicians understand the effectiveness of their interventions and the cost at which this effectiveness is obtained. Cost-effectiveness and cost-utility analyses have become crucial evaluative tools in medicine. Explicit articulation of comparative cost-effectiveness facilitates the allocation of limited resources. Physicians and policy-makers must evaluate such studies with caution, skepticism, and attention to the methods used.

Experimental human endotoxemia: a model of the systemic inflammatory response syndrome?

BACKGROUND

The normal human intravenous endotoxin model has been used for more than 50 years. It was once considered a possible model of sepsis, but, because no infection is present, it is better described as a model of systemic inflammation. We demonstrate herein that at least three of four systemic inflammatory response syndrome (SIRS) criteria are achieved with the model.

METHODS

Otherwise healthy human volunteers were given Escherichia coli endotoxin 2 ng/kg intravenously. Vital signs were monitored, and blood samples were collected over time for assessment of white blood cells (WBCs), cytokines, counter-regulatory hormones, and monocyte receptors.

RESULTS

The means of three variables (core temperature, heart rate, WBC) met the SIRS criteria. Compared with baseline, cytokines were elevated acutely, with tumor necrosis factor-alpha (TNFα) exhibiting temporal primacy over the other cytokines. Counter-regulatory hormones (cortisol, epinephrine) also were elevated acutely. Finally, the monocyte cell-surface receptors cluster of differentiation molecule (CD) 11b and TNF receptor-II were elevated and decreased, respectively.

CONCLUSIONS

The experimental human endotoxin model satisfies SIRS criteria and probably is best described as a model of Toll-like receptor 4 agonist-induced systemic inflammation.

Drotrecogin alfa (activated) in adults with septic shock

BACKGROUND

There have been conflicting reports on the efficacy of recombinant human activated protein C, or drotrecogin alfa (activated) (DrotAA), for the treatment of patients with septic shock.

METHODS

In this randomized, double-blind, placebo-controlled, multicenter trial, we assigned 1697 patients with infection, systemic inflammation, and shock who were receiving fluids and vasopressors above a threshold dose for 4 hours to receive either DrotAA (at a dose of 24 μg per kilogram of body weight per hour) or placebo for 96 hours. The primary outcome was death from any cause 28 days after randomization.

RESULTS

At 28 days, 223 of 846 patients (26.4%) in the DrotAA group and 202 of 834 (24.2%) in the placebo group had died (relative risk in the DrotAA group, 1.09; 95% confidence interval [CI], 0.92 to 1.28; P=0.31). At 90 days, 287 of 842 patients (34.1%) in the DrotAA group and 269 of 822 (32.7%) in the placebo group had died (relative risk, 1.04; 95% CI, 0.90 to 1.19; P=0.56). Among patients with severe protein C deficiency at baseline, 98 of 342 (28.7%) in the DrotAA group had died at 28 days, as compared with 102 of 331 (30.8%) in the placebo group (risk ratio, 0.93; 95% CI, 0.74 to 1.17; P=0.54). Similarly, rates of death at 28 and 90 days were not significantly different in other predefined subgroups, including patients at increased risk for death. Serious bleeding during the treatment period occurred in 10 patients in the DrotAA group and 8 in the placebo group (P=0.81).

CONCLUSIONS

DrotAA did not significantly reduce mortality at 28 or 90 days, as compared with placebo, in patients with septic shock. (Funded by Eli Lilly; PROWESS-SHOCK ClinicalTrials.gov number, NCT00604214.).