Continuation of chronic antiplatelet therapy is not associated with increased need for transfusions: a cohort study in critically ill septic patients

BACKGROUND

The decision to maintain or halt antiplatelet medication in septic patients admitted to intensive care units presents a clinical dilemma. This is due to the necessity to balance the benefits of preventing thromboembolic incidents and leveraging anti-inflammatory properties against the increased risk of bleeding.

METHODS

This study involves a secondary analysis of data from a prospective cohort study focusing on patients diagnosed with severe sepsis or septic shock. We evaluated the outcomes of 203 patients, examining mortality rates and the requirement for transfusion. The cohort was divided into two groups: those whose antiplatelet therapy was sustained (n = 114) and those in whom it was discontinued (n = 89). To account for potential biases such as indication for antiplatelet therapy, propensity score matching was employed.

RESULTS

Therapy continuation did not significantly alter transfusion requirements (discontinued vs. continued in matched samples: red blood cell concentrates 51.7% vs. 68.3%, p = 0.09; platelet concentrates 21.7% vs. 18.3%, p = 0.82; fresh frozen plasma concentrates 38.3% vs. 33.3%, p = 0.7). 90-day survival was higher within the continued group (30.0% vs. 70.0%; p < 0.001) and the Log-rank test (7-day survivors; p = 0.001) as well as Cox regression (both matched samples) suggested an association between continuation of antiplatelet therapy < 7 days and survival (HR: 0.24, 95%-CI 0.10 to 0.63, p = 0.004). Sepsis severity expressed by the SOFA score did not differ significantly in matched and unmatched patients (both p > 0.05).

CONCLUSIONS

The findings suggest that continuing antiplatelet therapy in septic patients admitted to intensive care units could be associated with a significant survival benefit without substantially increasing the need for transfusion. These results highlight the importance of a nuanced approach to managing antiplatelet medication in the context of severe sepsis and septic shock.

Staphylococcus aureus Alpha-Toxin in Deep Tracheal Aspirates—Preliminary Evidence for Its Presence in the Lungs of Sepsis Patients

The pore forming alpha-toxin (hemolysin A, Hla) of Staphylococcus aureus (S. aureus) is a major virulence factor with relevance for the pathogenicity of this bacterium, which is involved in many cases of pneumonia and sepsis in humans. Until now, the presence of Hla in the body fluids of potentially infected humans could only be shown indirectly, e.g., by the presence of antibodies against Hla in serum samples or by hemolysis testing on blood agar plates of bacterial culture supernatants of the clinical isolates. In addition, nothing was known about the concentrations of Hla actually reached in the body fluids of the infected hosts. Western blot analyses on 36 samples of deep tracheal aspirates (DTA) isolated from 22 hospitalized sepsis patients using primary antibodies against different epitopes of the Hla molecule resulted in the identification of six samples from five patients containing monomeric Hla (approx. 33 kDa). Two of these samples showed also signals at the molecular mass of heptameric Hla (232 kDa). Semiquantitative analyses of the samples revealed that the concentrations of monomeric Hla ranged from 16 to 3200 ng/mL. This is, to our knowledge, the first study directly showing the presence of S. aureus Hla in samples of airway surface liquid in human patients.

(1 → 3)-β-D-Glucan-guided antifungal therapy in adults with sepsis: the CandiSep randomized clinical trial

Purpose

To investigate whether (1 → 3)-β-d-Glucan (BDG)-guidance shortens time to antifungal therapy and thereby reduces mortality of sepsis patients with high risk of invasive Candida infection (ICI).

Methods

Multicenter, randomized, controlled trial carried out between September 2016 and September 2019 in 18 intensive care units enrolling adult sepsis patients at high risk for ICI. Patients in the control group received targeted antifungal therapy driven by culture results. In addition to targeted therapy, patients in the BDG group received antifungals if at least one of two consecutive BDG samples taken during the first two study days was ≥ 80 pg/mL. Empirical antifungal therapy was discouraged in both groups. The primary endpoint was 28-day-mortality.

Results

339 patients were enrolled. ICI was diagnosed in 48 patients (14.2%) within the first 96 h after enrollment. In the BDG-group, 48.8% (84/172) patients received antifungals during the first 96 h after enrollment and 6% (10/167) patients in the control group. Death until day 28 occurred in 58 of 172 patients (33.7%) in the BDG group and 51 of 167 patients (30.5%) in the control group (relative risk 1.10; 95% confidence interval, 0.80–1.51; p = 0.53). Median time to antifungal therapy was 1.1 [interquartile range (IQR) 1.0–2.2] days in the BDG group and 4.4 (IQR 2.0–9.1, p < 0.01) days in the control group.

Conclusions

Serum BDG guided antifungal treatment did not improve 28-day mortality among sepsis patients with risk factors for but unexpected low rate of IC. This study cannot comment on the potential benefit of BDG-guidance in a more selected at-risk population.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00134-022-06733-x.

Fever and hypothermia represent two populations of sepsis patients and are associated with outside temperature

Background

Fever and hypothermia have been observed in septic patients. Their influence on prognosis is subject to ongoing debates.

Methods

We did a secondary analysis of a large clinical dataset from a quality improvement trial. A binary logistic regression model was calculated to assess the association of the thermal response with outcome and a multinomial regression model to assess factors associated with fever or hypothermia.

Results

With 6542 analyzable cases we observed a bimodal temperature response characterized by fever or hypothermia, normothermia was rare. Hypothermia and high fever were both associated with higher lactate values. Hypothermia was associated with higher mortality, but this association was reduced after adjustment for other risk factors. Age, community-acquired sepsis, lower BMI and lower outside temperatures were associated with hypothermia while bacteremia and higher procalcitonin values were associated with high fever.

Conclusions

Septic patients show either a hypothermic or a fever response. Whether hypothermia is a maladaptive response, as indicated by the higher mortality in hypothermic patients, or an adaptive response in patients with limited metabolic reserves under colder environmental conditions, remains an open question.

Trial registration The original trial whose dataset was analyzed was registered at ClinicalTrials.gov (NCT01187134) on August 23, 2010, the first patient was included on July 1, 2011.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-021-03776-2.

Pathogen-specific antibody profiles in patients with severe systemic infections

Infections are often caused by pathobionts, endogenous bacteria that belong to the microbiota. Trauma and surgical intervention can allow bacteria to overcome host defences, ultimately leading to sepsis if left untreated. One of the main defence strategies of the immune system is the production of highly specific antibodies. In the present proof-of-concept study, plasma antibodies against 9 major pathogens were measured in sepsis patients, as an example of severe systemic infections. The binding of plasma antibodies to bacterial extracellular proteins was quantified using a semi-automated immunoblot assay. Comparison of the pathogen-specific antibody levels before and after infection showed an increase in plasma IgG in 20 out of 37 tested patients. This host-directed approach extended the results of pathogen-oriented microbiological and PCR diagnostics: a specific antibody response to additional bacteria was frequently observed, indicating unrecognised poly-microbial invasion. This might explain some cases of failed, seemingly targeted antibiotic treatment.

On-site blood culture incubation shortens the time to knowledge of positivity and microbiological results in septic patients

Introduction

To determine whether on-site incubation of blood cultures at the intensive care unit (ICU) improves not only the time to incubation but also time to positivity, time to knowledge of positivity and time to results (identification and antibiotic susceptibility testing).

Methods

This observational single-centre study in ICU patients with severe sepsis and septic shock investigated the impact of blood culture incubation immediately on-site at the ICU (ICU group) by comparison with traditional processing in a remote laboratory (LAB group) on different time intervals of blood culture diagnostics from obtaining blood to clinician notification of final result. The effect of on-site incubation was evaluated in Kaplan-Meier estimates for the time to positivity, time to knowledge of positivity and time to microbiological results and a linear mixed model was built.

Results

A total of 3,549 blood culture sets from 657 ICU patients were analysed: 2,381 in the LAB group and 1,168 in the ICU group. Overall, 660 (18.6%) blood culture sets were positive and 2,889 (81.4%) sets remained negative. On-site incubation was associated with reduced time to knowledge of positivity (46.9 h [CI 43.4–50.8 h] vs. 28.0 h [CI 23.6–32.2 h], p < 0.001) and reduced time to result (61.4 h [CI 58.4–64.8 h] vs. 42.1 h [CI 39.1–47.5 h], p < 0.001). In blood cultures processed instantaneously at the ICU compared to incubation in the remote laboratory within 4 h, the time to microbiological result was significantly reduced by 8.5 h (p < 0.001). Pre-existing anti-infective therapy had no significant impact on diagnostic time intervals.

Conclusions

Instantaneous incubation of blood cultures in the ICU compared to incubation in a remote laboratory significantly improves time to knowledge to positivity and time to result. These effects are even more pronounced during off-hours of the microbiological laboratory. The results underline the importance of 24/7 diagnostics to provide round-the-clock processing of blood culture samples in patients with sepsis and septic shock and an immediate to communication of the results to the clinicians.

Vitamin C in sepsis

PURPOSE OF REVIEW

This narrative review summarizes recent insights into the role of vitamin C in sepsis.

RECENT FINDINGS

Septic shock remains a major source of morbidity and mortality in critically ill patients. Although many nutritional supplements have previously been tested unsuccessfully, vitamins are still being explored as a therapeutic option in septic patients. In particular, vitamin C-containing regimens as adjunctive therapy in sepsis have received much attention.

SUMMARY

In-vitro evidence supports a critical role for vitamin C in cellular mechanisms relevant to the pathophysiology of sepsis. However, whether this justifies therapeutic use of vitamin C in septic patients remains uncertain.

Effect of Hydrocortisone on Development of Shock Among Patients With Severe Sepsis: The HYPRESS Randomized Clinical Trial

IMPORTANCE

Adjunctive hydrocortisone therapy is suggested by the Surviving Sepsis Campaign in refractory septic shock only. The efficacy of hydrocortisone in patients with severe sepsis without shock remains controversial.

OBJECTIVE

To determine whether hydrocortisone therapy in patients with severe sepsis prevents the development of septic shock.

DESIGN, SETTING, AND PARTICIPANTS

Double-blind, randomized clinical trial conducted from January 13, 2009, to August 27, 2013, with a follow-up of 180 days until February 23, 2014. The trial was performed in 34 intermediate or intensive care units of university and community hospitals in Germany, and it included 380 adult patients with severe sepsis who were not in septic shock.

INTERVENTIONS

Patients were randomly allocated 1:1 either to receive a continuous infusion of 200 mg of hydrocortisone for 5 days followed by dose tapering until day 11 (n = 190) or to receive placebo (n = 190).

MAIN OUTCOMES AND MEASURES

The primary outcome was development of septic shock within 14 days. Secondary outcomes were time until septic shock, mortality in the intensive care unit or hospital, survival up to 180 days, and assessment of secondary infections, weaning failure, muscle weakness, and hyperglycemia (blood glucose level >150 mg/dL [to convert to millimoles per liter, multiply by 0.0555]).

RESULTS

The intention-to-treat population consisted of 353 patients (64.9% male; mean [SD] age, 65.0 [14.4] years). Septic shock occurred in 36 of 170 patients (21.2%) in the hydrocortisone group and 39 of 170 patients (22.9%) in the placebo group (difference, -1.8%; 95% CI, -10.7% to 7.2%; P = .70). No significant differences were observed between the hydrocortisone and placebo groups for time until septic shock; mortality in the intensive care unit or in the hospital; or mortality at 28 days (15 of 171 patients [8.8%] vs 14 of 170 patients [8.2%], respectively; difference, 0.5%; 95% CI, -5.6% to 6.7%; P = .86), 90 days (34 of 171 patients [19.9%] vs 28 of 168 patients [16.7%]; difference, 3.2%; 95% CI, -5.1% to 11.4%; P = .44), and 180 days (45 of 168 patients [26.8%] vs 37 of 167 patients [22.2%], respectively; difference, 4.6%; 95% CI, -4.6% to 13.7%; P = .32). In the hydrocortisone vs placebo groups, 21.5% vs 16.9% had secondary infections, 8.6% vs 8.5% had weaning failure, 30.7% vs 23.8% had muscle weakness, and 90.9% vs 81.5% had hyperglycemia.

CONCLUSIONS AND RELEVANCE

Among adults with severe sepsis not in septic shock, use of hydrocortisone compared with placebo did not reduce the risk of septic shock within 14 days. These findings do not support the use of hydrocortisone in these patients.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00670254.

Discrepant post filter ionized calcium concentrations by common blood gas analyzers in CRRT using regional citrate anticoagulation

Introduction

Ionized calcium (iCa) concentration is often used in critical care and measured using blood gas analyzers at the point of care. Controlling and adjusting regional citrate anticoagulation (RCA) for continuous renal replacement therapy (CRRT) involves measuring the iCa concentration in two samples: systemic with physiological iCa concentrations and post filter samples with very low iCa concentrations. However, modern blood gas analyzers are optimized for physiological iCa concentrations which might make them less suitable for measuring low iCa in blood with a high concentration of citrate. We present results of iCa measurements from six different blood gas analyzers and the impact on clinical decisions based on the recommendations of the dialysis’ device manufacturer.

Method

The iCa concentrations of systemic and post filter samples were measured using six distinct, frequently used blood gas analyzers. We obtained iCa results of 74 systemic and 84 post filter samples from patients undergoing RCA for CRRT at the University Medicine of Greifswald.

Results

The systemic samples showed concordant results on all analyzers with median iCa concentrations ranging from 1.07 to 1.16 mmol/L. The medians of iCa concentrations for post filter samples ranged from 0.21 to 0.50 mmol/L. Results of >70 % of the post filter samples would lead to major differences in decisions regarding citrate flow depending on the instrument used.

Conclusion

Measurements of iCa in post filter samples may give misleading information in monitoring the RCA. Recommendations of the dialysis manufacturer need to be revised. Meanwhile, little weight should be given to post filter iCa. Reference methods for low iCa in whole blood containing citrate should be established.

[Application of the laryngeal mask for elective percutaneous dilatation tracheotomy]

Percutaneous dilatational tracheostomy is an increasingly accepted procedure for bed-side tracheostomy. The exact positioning of the endotracheal tube, the localization of the point for puncturing the trachea and damage to the endotracheal tube and the cuff as well as to the bronchoscope due to the puncturing process are technical problems which can endanger the course of the operation. In a prospective randomized study, we examined whether use of the laryngeal mask airway (LMA) is a real alternative to the endotracheal tube during tracheostomy. Of 48 consecutive patients only 43 fulfilled all criteria for this study: PaO2 > 100 mmHg, PaCO2 < 45 mmHg (in patients with head injury < 35 mmHg) under intermittent positive pressure ventilation (IPPV) with a mean ventilation pressure of < 25 mmHg and an FiO2 of 1.0. Patients with intestinal obstruction, hemorrhages of the mouth and nose and unfavourable anatomic conditions were not included in this study. Three more patients had to be excluded from the study because of technical problems. In 21 patients tracheostomy was performed using an endotracheal tube (ET group) and in 19 patients using a LMA (LM group). After positioning of the endotracheal tube or the LMA, tracheostomy was performed in the usual way. Arterial blood gases (PaO2 and PaCO2) were investigated before positioning of the endotracheal tube or the LMA, five minutes after this procedure and five minutes after the end of tracheostomy. Mean arterial pressure (MAP), heart frequency (HF) and peripheral oxygen saturation (SpO2), endexpiratory CO2 partial pressure (PetCO2) and minute ventilation volume (MVV) were registered every 60 seconds. The ET group and LM group did not differ regarding basic diseases, age and severity of illness. Before the beginning of tracheostomy, there were no differences in MAP, HF, SpO2, PetCO2 and PaCO2 between the two groups. Before tracheostomy, only PaO2 was significantly higher in the LM group than in the ET group. Immediately before the insertion of the tracheal cannula and five minutes after the end of tracheostomy, there were no differences in the measured parameters of the two groups. An increase in PetCO2 and a decrease in minute ventilation volume were observed in both groups. Regarding technical complications, the LMA is a safe alternative to the endotracheal tube. The choice of method should depend on the basic disease and the patient's ventilation requirements at the time of tracheostomy, while there is still a call for safe instruments guaranteeing sufficient sealing of the respiratory tract during the dilatational tracheostomy and simultaneous avoidance of technical problems during puncturing of the trachea and widening of the point of puncturing.

The specificity and affinity of polyclonal antibodies raised in rabbits against a hapten conjugated to rabbit serum albumin

In this study, rabbit antisera to hapten-rabbit serum albumin conjugates were investigated regarding antibody titer, affinity, specificity, and affinity distribution. Methyl phosphonic acid p-amino-phenyl 1,2,2-trimethylpropyldiester (MATP) served as model hapten. Four MATP-rabbit serum albumin conjugates with various hapten densities (with and without spacer) were synthesized and used for immunization of rabbits. Antisera were collected over a 130 day-period and characterized with different ELISA methods. We found that immunogens with rabbit serum albumin gave antisera with lower titers, but similar affinity as compared to polyclonal or monoclonal antibodies obtained with non-rabbit protein as carrier protein. Immunogens with a low hapten density led to higher final titers without affecting antibody affinity or specificity. Immunogens containing a bridging group resulted in higher antibody affinity with a changed specificity. The pattern of antibody affinity distribution differed considerably among individual rabbits and showed a non-Gaussian subpopulation distribution.