95 research outputs found
Reduced red blood cell deformability over time is associated with a poor outcome in septic patients
No full textBackground: To investigate changes in red blood cell (RBC) rheology over time in critically ill patients with sepsis and their relationship with outcome.
Methods: In this prospective, non-interventional study, RBC rheology was assessed using the Laser-assisted Optical Rotational Cell Analyzer in a convenience sample of intensive care unit (ICU) patients with (n = 64) and without (n = 160) sepsis.
Results were compared to measures in healthy volunteers (n = 20). RBC rheology was also assessed on days 1 and 3 of the ICU stay in 32 of the non-septic and 19 of the septic patients. RBC deformability was determined by the elongation index (El) in relation to the shear stress (0.3 to 50 Pa) applied to the RBC membrane. An aggregation index (AI) was assessed simultaneously with the same device. Results: The ICU mortality rate of the septic patients was 31%. RBC deformability was already reduced in septic patients at ICU admission, an effect that persisted during the study period and worsened in the non-survivors for the large majority of shear stresses studied (e.g., El for 50 Pa of shear stress was 0.527 +/- 0.064 in non-survivors vs. 0.566 +/- 0.034 in survivors, p < 0.05). These changes were not observed in non-septic patients. The AI was more elevated in septic than in non-septic patients at ICU admission, but had no prognostic value.
Conclusions: Alterations in RBC rheology, including reduced deformability and increased aggregation, occur early in septic patients and reductions in RBC deformability over time are associated with a poor outcome.Background: To investigate changes in red blood cell (RBC) rheology over time in critically ill patients with sepsis and their relationship with outcome. Methods: In this prospective, non-interventional study, RBC rheology was assessed using the Laser-assisted Optical Rotational Cell Analyzer in a convenience sample of intensive care unit (ICU) patients with (n =64) and without (n =160) sepsis. Results were compared to measures in healthy volunteers (n =20). RBC rheology was also assessed on days 1 and 3 of the ICU stay in 32 of the non-septic and 19 of the septic patients. RBC deformability was determined by the elongation index (EI) in relation to the shear stress (0.3 to 50. Pa) applied to the RBC membrane. An aggregation index (AI) was assessed simultaneously with the same device. Results: The ICU mortality rate of the septic patients was 31%. RBC deformability was already reduced in septic patients at ICU admission, an effect that persisted during the study period and worsened in the non-survivors for the large majority of shear stresses studied (e.g., EI for 50. Pa of shear stress was 0.527. ±. 0.064 in non-survivors vs. 0.566. ±. 0.034 in survivors, p. < 0.05). These changes were not observed in non-septic patients. The AI was more elevated in septic than in non-septic patients at ICU admission, but had no prognostic value. Conclusions: Alterations in RBC rheology, including reduced deformability and increased aggregation, occur early in septic patients and reductions in RBC deformability over time are associated with a poor outcome
Effects of a selective iNOS inhibitor versus norepinephrine in the treatment of septic shock.
No full textInhibition of NOS is not beneficial in septic shock; selective inhibition of the inducible form (iNOS) may represent a better option. We compared the effects of the selective iNOS inhibitor BYK191023 with those of norepinephrine (NE) in a sheep model of septic shock. Twenty-four anesthetized, mechanically ventilated ewes received 1.5 g/kg body weight of feces into the abdominal cavity to induce sepsis. Animals were randomized into three groups (each n = 8): NE-only, BYK-only, and NE + BYK. The sublingual microcirculation was evaluated with sidestream dark-field videomicroscopy. MAP was higher in the NE + BYK group than in the other groups, but there were no significant differences in cardiac index or systemic vascular resistance. Mean pulmonary arterial pressure was lower in BYK-treated animals than in the NE-only group. PaO2/FiO2 was higher and lactate concentration lower in the BYK groups than in the NE-only group. Mesenteric blood flow was higher in BYK groups than in the NE-only group. Renal blood flow was higher in the NE + BYK group than in the other groups. Functional capillary density and proportion of perfused vessels were higher in the BYK groups than in the NE-only group 18 h after induction of peritonitis. Survival times were similar in the three groups. In this model of peritonitis, selective iNOS inhibition had more beneficial effects than NE on pulmonary artery pressures, gas exchange, mesenteric blood flow, microcirculation, and lactate concentration. Combination of this selective iNOS inhibitor with NE allowed a higher arterial pressure and renal blood flow to be maintained.Comparative StudyJournal ArticleSCOPUS: ar.jinfo:eu-repo/semantics/publishe
Limited effects of activated protein C on red blood cell deformability.
No full textBackground: Alterations of the microcirculation are common in critically ill patients and persistence of these alterations is associated with poor outcome. Infusion of high doses of activated protein C can ameliorate the microcirculation. Because red blood cells (RBCs) play an essential role in oxygen transport to the tissues, we studied the effects of activated protein C on RBC deformability in septic patients. Methods: RBC deformability, assessed by ektacytometry (LORCA system) for shear stresses between 0.30 and 50 Pa, was compared in healthy volunteers and in septic patients before and during activated protein C infusion. Results: RBC deformability was altered in septic patients compared to healthy volunteers. RBC deformability improved transiently during activated protein C infusion for shear stresses of 4.89 and 7.78 Pa, but the elongation index increased by just 3.4 and 3.2%, respectively. Conclusions: RBC deformability was altered in sepsis. Activated protein C had no clinically relevant effects on RBC deformability as assessed using ektacytometry.JOURNAL ARTICLESCOPUS: ar.jinfo:eu-repo/semantics/publishe
What do we know about thromboprophylaxis and its monitoring in critically ill patients?
No full textVenous thromboembolism (VTE), including deep vein thrombosis and pulmonary embolism, is an important complication in patients hospitalized in intensive care units (ICU). Thromboprophylaxis is mainly performed with Low Molecular Weight Heparin (LMWH) and, in some specific patients, with Unfractionated Heparin (UFH). These intensive units are an environment where individual patient variability is extreme and where traditional antithrombotic protocols are frequently ineffective. This was known for a long time, but the hospitalization of many patients with COVID-19 inflammatory storms suddenly highlighted this knowledge. It is therefore reasonable to propose variable antithrombotic prevention protocols based initially on a series of individual criteria (weight, BMI, and thrombotic risks). Secondly, they should be adjusted by the monitoring of anticoagulant activity, preferably by measuring the anti-Xa activity. However, we still face unresolved questions, such as once- or twice-daily LMWH injections, monitoring at the peak and/or trough, and poorly defined therapeutic targets. Equally surprisingly, we observed a lack of standardization of the anti-Xa activity kits.SCOPUS: ar.jinfo:eu-repo/semantics/publishe
Predictive value of C-reactive protein in critically ill patients after abdominal surgery
No full textOBJECTIVES: The development of sepsis after abdominal surgery is associated with high morbidity and mortality. Due to inflammation, it may be difficult to diagnose infection when it occurs, but measurement of C-reactive protein could facilitate this diagnosis. In the present study, we evaluated the predictive value and time course of C-reactive protein in relation to outcome in patients admitted to the intensive care unit (ICU) after abdominal surgery. METHODS: We included patients admitted to the ICU after abdominal surgery over a period of two years. The patients were divided into two groups according to their outcome: favorable (F; left the ICU alive, without modification of the antibiotic regimen) and unfavorable (D; death in the ICU, surgical revision with or without modification of the antibiotic regimen or just modification of the regimen). We then compared the highest C-reactive protein level on the first day of admission between the two groups. RESULTS: A total of 308 patients were included: 86 patients had an unfavorable outcome (group D) and 222 had a favorable outcome (group F). The groups were similar in terms of leukocytosis, neutrophilia, and platelet count. C-reactive protein was significantly higher at admission in group D and was the best predictor of an unfavorable outcome, with a sensitivity of 74% and a specificity of 72% for a threshold of 41 mg/L. No changes in C-reactive protein, as assessed based on the delta C-reactive protein, especially at days 4 and 5, were associated with a poor prognosis. CONCLUSIONS: A C-reactive protein cut-off of 41 mg/L during the first day of ICU admission after abdominal surgery was a predictor of an adverse outcome. However, no changes in the C-reactive protein concentration, especially by day 4 or 5, could identify patients at risk of death
Microcirculation
No full textThe microcirculation is the part of the circulation where oxygen, nutrients, hormones, and waste products are exchanged between circulating blood and parenchymal cells.The microcirculation includes not only all the vessels with a diameter <100 μm but also the interactions between blood components (circulating cells, coagulation factors), the vessels lined by the endothelium, and the glycocalyx.Facultad de Ciencias Médica
Predictive value of C-reactive protein in critically ill patients after abdominal surgery
No full textOBJECTIVES: The development of sepsis after abdominal surgery is associated with high morbidity and mortality. Due to inflammation, it may be difficult to diagnose infection when it occurs, but measurement of C-reactive protein could facilitate this diagnosis. In the present study, we evaluated the predictive value and time course of C-reactive protein in relation to outcome in patients admitted to the intensive care unit (ICU) after abdominal surgery. METHODS: We included patients admitted to the ICU after abdominal surgery over a period of two years. The patients were divided into two groups according to their outcome: favorable (F; left the ICU alive, without modification of the antibiotic regimen) and unfavorable (D; death in the ICU, surgical revision with or without modification of the antibiotic regimen or just modification of the regimen). We then compared the highest C-reactive protein level on the first day of admission between the two groups. RESULTS: A total of 308 patients were included: 86 patients had an unfavorable outcome (group D) and 222 had a favorable outcome (group F). The groups were similar in terms of leukocytosis, neutrophilia, and platelet count. C-reactive protein was significantly higher at admission in group D and was the best predictor of an unfavorable outcome, with a sensitivity of 74% and a specificity of 72% for a threshold of 41 mg/L. No changes in C-reactive protein, as assessed based on the delta C-reactive protein, especially at days 4 and 5, were associated with a poor prognosis. CONCLUSIONS: A C-reactive protein cut-off of 41 mg/L during the first day of ICU admission after abdominal surgery was a predictor of an adverse outcome. However, no changes in the C-reactive protein concentration, especially by day 4 or 5, could identify patients at risk of death.SCOPUS: ar.jinfo:eu-repo/semantics/publishe
Effects of Preconditioning on RBC Deformability in Critically Ill Patients
No full textRBCs from critically ill patients have depressed deformability, especially in sepsis. Prolonged exposure of RBCs from healthy volunteers to physiologic shear stress (the preconditioning technique) has been associated with improved deformability, but the effect of preconditioning on RBCs from critically ill patients with or without sepsis has never been studied. DESIGN: Prospective study. SETTING: A 32-bed medico-surgical ICU and a university-affiliated cell biology laboratory. SUBJECTS: RBCs from 26 healthy volunteers and 40 critically ill patients (20 with and 20 without sepsis). INTERVENTIONS: RBC deformability was measured using the elongation index (EI) with an ektacytometer, at shear stress levels ranging from 0.3 to 50 Pa. To assess the effects of preconditioning in the three groups, we measured EI after first applying a shear stress of 5 Pa for 300 seconds. To study the potential mechanisms involved in preconditioning, we looked at deformability after incubation of an RBC solution from the healthy volunteers with glutaraldehyde, a membrane-stabilizing protein, and neuraminidase, an enzyme that releases membrane sialic acid. MEASUREMENTS AND MAIN RESULTS: Baseline RBC deformability was significantly depressed in the septic patients compared with the volunteers at all shear stress levels greater than or equal to 4.89 Pa. Preconditioning improved deformability only in the volunteers (at shear stress levels of 0.48 and 0.76 Pa). Among the critically ill patients, preconditioning worsened RBC deformability at higher shear stress levels. After incubation (with glutaraldehyde or neuraminidase) of RBCs from five volunteers in whom preconditioning had significantly improved deformability, the positive effect of preconditioning was lost with glutaraldehyde. CONCLUSIONS: RBC deformability is depressed in septic patients. There was a deleterious effect of preconditioning on RBC deformability in septic patients, unlike the positive effect on RBCs from healthy volunteers. The effect of preconditioning may be associated with elasticity of the cell membrane
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