Long-term survivors of ARDS describe a good overall health-related quality of life. Major impairments in mental health domains of health-related quality of life are associated with the development of posttraumatic stress disorder and are a possible result of traumatic experiences during ICU therapy.
Long-term survivors of ARDS have a significant reduction in HRQL and the presence of multiple PF impairments is associated with maximal decrements in HRQL.
Infusion of stress doses of hydrocortisone reduced the time to cessation of vasopressor therapy in human septic shock. This was associated with a trend to earlier resolution of sepsis-induced organ dysfunctions. Overall shock reversal and mortality were not significantly different between the groups in this low-sized single-center study.
Production of oxygen radicals is required for both microbicidal and tissue-toxic effector functions of granulocytes. Inasmuch as an ambivalent role of polymorphonuclear leukocytes (PMNs) may become apparent during sepsis, we studied levels of hydrogen peroxide (H2O2) production by PMNs depending upon the nature of different particulate and soluble stimuli in patients with increasing sepsis severity. Patients with sepsis (n = 15), severe sepsis (n = 12), or septic shock (n = 33) were prospectively enrolled in the study. Healthy volunteers of comparable age and sex served as controls (n = 50). Unopsonized and opsonized zymosan particles were used to assess adhesion, phagocytosis, and the associated H2O2 production. Zymosan particles are rich in beta-glucans and lectin structures that are known to trigger H2O2 production via two major non-toll-like receptor pathogen recognition receptors, comprising the lectin-binding site in the alpha-chain (CD11b) of the complement receptor type 3 and the more recently identified nonclassical C-type lectin, dectin-1. To determine H2O2 production upon cell activation by soluble stimuli, PMNs were activated by the chemotactic tripeptide (N-formyl-methionyl-leucyl-phenylalanine [fMLP]) alone or after priming of cells by preincubation with tumor necrosis factor alpha. To get insight into the changes of fMLP receptor classical intracellular signaling pathways, PMNs were also incubated with the calcium ionophore A23187 and the phorbol ester phorbol myristate acetate, bypassing receptor-dependent signal transduction to directly activate calcium/calmodulin kinase- and protein kinase C-dependent pathways, respectively. As compared with healthy volunteers, levels of H2O2 production by PMNs from septic patients varied depending upon the nature of the activating signal: reduced (zymosan), unchanged (phorbol myristate acetate, opsonized zymosan), and enhanced (spontaneous, fMLP, fMLP + tumor necrosis factor alpha, A23187), with the changes most pronounced in patients with septic shock. Specifically, phagocytosis of zymosan and the associated H2O2 production were significantly decreased whereas spontaneous and stimulated H2O2 production elicited by soluble stimuli strongly increased. Thus, these findings suggest the development of a PMN dysfunction syndrome in patients with increasing sepsis severity. Moreover, as binding of zymosan particles to the PMNs' surface remained unchanged despite increasingly suppressed phagocytosis and associated H2O2 production, observed effects are likely to reflect defects in signaling by the lectin-binding site of CD11b and/or the beta-glucan receptor dectin-1, respectively.
In patients with septic shock stress doses of HC exert beneficial effects in terms of improvements in hemodynamics, decrease in pro-inflammatory mediators, and oxidative stress without the compromise of opsonization-dependent phagocytic neutrophil functions; thus, HC treatment does not aggravate non-specific immunosuppression but instead improves innate immunity in the early stage of septic shock.
Cardiac output measurement is part of routine monitoring in critically ill patients. In patients on extracorporeal lung assist, thermodilution cardiac output measurement may lead to erroneous results caused by indicator loss into the extracorporeal circuit. Seven patients on venovenous extracorporeal lung assist were studied using different extracorporeal blood flows. We compared conventional thermodilution cardiac output determinations with dye dilution cardiac output measurement, with dye injection into the pulmonary artery. The latter method is not affected by the extracorporeal circuit. The conventional thermodilution method overestimated cardiac output up to a maximum of 300%, providing results up to 10 L/min higher than true cardiac output. The mean difference between thermodilution and true cardiac output as determined by dye dilution with pulmonary artery indicator injection was 3.0 +/- 2.41 L/min. There was no correlation between thermodilution cardiac output values and true cardiac output (r = 0.06). We conclude that conventional thermodilution is not a suitable method for cardiac output measurement in patients on extracorporeal lung assist, especially if high extracorporeal blood flows are applied.
Inasmuch as polymorphonuclear leukocytes (PMNs) play a major role in antibacterial defense but can also cause substantial tissue injury, drugs are needed which are able to attenuate tissue-toxic PMN reactions without inhibiting bactericidal mechanisms. Adenosine as a retaliatory metabolite is produced in response to metabolically unfavorable conditions like inflammation. However, it is not known whether adenosine can selectively downregulate adverse PMN reactions in sepsis. In this prospective clinical study, we characterized the effects of adenosine ex vivo on PMN functions in patients with septic shock ([SS] n = 33) and healthy volunteers ([HV] n = 33). The PMNs were primed by tumor necrosis factor-alpha (TNF-alpha) and subsequently stimulated with N-formyl methionyl-leucyl-phenylalanine (fMLP) to test for the formation of hydrogen peroxide (H2O2) in response to soluble inflammatory stimuli. The PMNs were also challenged by opsonized zymosan particles to assess adhesion, phagocytosis, and the associated H2O2 production. As compared with HV, PMNs from SS patients showed strongly enhanced tissue-toxic H2O2 production elicited by TNF-alpha/fMLP. Increasing concentrations of adenosine dose-dependently reduced this tissue-toxic H2O2 production in both groups with a half-maximal inhibitory concentration of 25 nmol/L and 114 nmol/L in HV and SS patients, respectively. This 4.6-fold decrease in the adenosine-mediated inhibition of PMNs from patients with septic shock was compensated by a 3-fold increase in the plasma concentrations of the nucleoside (HV, 42.5 +/- 2.9 nmol/L vs. SS, 125.6 +/- 18.2 nmol/L; mean +/- SEM). When the effects of adenosine were tested at a very high A2A receptor saturating concentration of 10 mol/L, neither adhesion, phagocytosis, nor the associated H2O2 production induced by opsonized zymosan was affected in both groups. These results were confirmed by the highly selective A2A agonist, CGS21680.Thus, adenosine or A2A agonists may be useful to selectively inhibit the potentially tissue-toxic H2O2 production elicited by soluble inflammatory mediators in patients with septic shock.
A 19-year-old female patient had developed acute respiratory and renal failure after a prolonged period (many months) of antibiotic resistant otitis, sinusitis and mastoiditis. The patient had required intubation at another hospital and there was a history of tension pneumothorax and cardiopulmonary resuscitation during mechanical ventilation. Emergency extracorporeal membrane oxygenation (ECMO) for acute hypercapnic and hypoxic respiratory failure was instituted and the patient was transported to our institution while on ECMO. The patient was treated empirically for suspected pulmonary and systemic infection and received hydrocortisone (0.18 mg/kg/h) as part of a protocol-driven treatment of septic shock in addition to antibiotic and antimycotic regime. The use of ECMO was required for 10 and mechanical ventilation for another 50 days after admission. After successful extubation, central nervous system dysfunction became evident with a somnolent and generally unresponsive patient. When the hydrocortisone dose was gradually tapered, the clinical status of the patient further deteriorated, pulmonary gas exchange worsened and she developed renal failure with proteinura and hematuria. A renal biopsy was performed demonstrating vasculitis and focal segmental glomerulonephritis, a systemic granulomatous vasculitis was suspected; the serum was tested for anti-proteinase 3 antibodies (PR3-ANCA) and turned out to be positive (17.5 U/ml; normal range < 7 U/ml). The morphologic findings from renal biopsy, the positive test for antiproteinase 3 antibodies and the pulmonary-renal involvement with evidence of multisystem disease established the diagnosis of Wegener's granulomatosis. Immunosuppressive therapy with cyclophosphamide and prednisolone was instituted resulting in rapid improvement with recovery of pulmonary, renal and central nervous system function within two weeks. The use of ECMO in this patient served as a life-saving immediate measure usefull to "buy time" until a definite diagnosis could be established. ARDS represents an uniform pulmonary reaction to a large number of different noxious stimuli and disease entities. This case demonstrates that intensive care physicians caring for critically ill patients with ARDS should include even rare causes of pulmonary injury into their differential diagnosis.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.