To investigate whether the respiratory variation in inferior vena cava diameter (ΔDIVC) could be related to fluid responsiveness in mechanically ventilated patients. Prospective clinical study. Medical ICU of a non-university hospital. Mechanically ventilated patients with septic shock (n=39). Volume loading with 8 mL/kg of 6% hydroxyethylstarch over 20 min. Cardiac output and ΔDIVC were assessed by echography before and immediately after the standardized volume load. Volume loading induced an increase in cardiac output from 5.7±2.0 to 6.4±1.9 L/min (P<0.001) and a decrease in ΔDIVC from 13.8±13.6 vs 5.2±5.8% (P<0.001). Sixteen patients responded to volume loading by an increase in cardiac output ≥15% (responders). Before volume loading, the ΔDIVC was greater in responders than in non-responders (25±15 vs 6±4%, P<0.001), closely correlated with the increase in cardiac output (r=0.82, P<0.001), and a 12% ΔDIVC cut-off value allowed identification of responders with positive and negative predictive values of 93% and 92%, respectively. Analysis of ΔDIVC is a simple and non-invasive method to detect fluid responsiveness in mechanically ventilated patients with septic shock.

The respiratory variation in inferior vena cava diameter as a guide to fluid therapy

The only natural reservoir of Neisseria meningitidis is the human nasopharyngeal mucosa. Depending on age, climate, country, socioeconomic status, and other factors, approximately 10% of the human population harbors meningococci in the nose. However, invasive disease is relatively rare, as it occurs only when the following conditions are fulfilled: (i) contact with a virulent strain, (ii) colonization by that strain, (iii) penetration of the bacterium through the mucosa, and (iv) survival and eventually outgrowth of the meningococcus in the bloodstream. When the meningococcus has reached the bloodstream and specific antibodies are absent, as is the case for young children or after introduction of a new strain in a population, the ultimate outgrowth depends on the efficacy of the innate immune response. Massive outgrowth leads within 12 h to fulminant meningococcal sepsis (FMS), characterized by high intravascular concentrations of endotoxin that set free high concentrations of proinflammatory mediators. These mediators belonging to the complement system, the contact system, the fibrinolytic system, and the cytokine system induce shock and diffuse intravascular coagulation. FMS can be fatal within 24 h, often before signs of meningitis have developed. In spite of the increasing possibilities for treatment in intensive care units, the mortality rate of FMS is still 30%. When the outgrowth of meningococci in the bloodstream is impeded, seeding of bacteria in the subarachnoidal compartment may lead to overt meningitis within 24 to 36 h. With appropriate antibiotics and good clinical surveillance, the mortality rate of this form of invasive disease is 1 to 2%. The overall mortality rate of meningococcal disease can only be reduced when patients without meningitis, i.e., those who may develop FMS, are recognized early. This means that the fundamental nature of the disease as a meningococcus septicemia deserves more attention.

Update on Meningococcal Disease with Emphasis on Pathogenesis and Clinical Management

Background and Purpose:The diverse causes of right-sided heart failure (RHF) include, among others, primary cardiomyopathies with right ventricular (RV) involvement, RV ischemia and infarction, vol...

Evaluation and Management of Right-Sided Heart Failure: A Scientific Statement From the American Heart Association.

Pro- and antiinflammatory cytokines and mediators were measured in 39 patients with acute life-threatening meningococcal infections classified into 3 groups: A, meningitis without shock (n = 20); B, meningitis with shock (n = 9); and C, shock without meningitis (n = 10). The plasma concentrations of proinflammatory endotoxin, tumor necrosis factor-alpha (TNF-alpha), interleukin (IL)-6, and IL-8 and antiinflammatory cytokines and mediators IL-1 receptor antagonist, IL-10, and soluble TNF receptors p55 and p75 were strongly associated with this classification; the highest concentrations were in group C. IL-4 was not measurable. IL-1 beta was increased only in rapidly fatal cases. In addition, cerebrospinal fluid (CSF) was analyzed in 21 patients for TNF-alpha and its soluble receptors. In CSF, these compounds were mainly increased in group A, reflecting an intrathecal compartmentalized cytokine production. It is concluded that both pro- and antiinflammatory mediators are simultaneously increased and are strongly associated with a classification based on simple clinical parameters.

https://repository.ubn.ru.nl/bitstream/handle/2066/22343/22343___.PDF;sequence=1

Correlation between proinflammatory cytokines and antiinflammatory mediators and the severity of disease in meningococcal infections

https://www.thelancet.com/pdfs/journals/lancet/PIIS0140673697063563.pdf

Use of protein-C concentrate, heparin, and haemodiafiltration in meningococcus-induced purpura fulminans

The study objective was to describe the clinical, biologic, and hemodynamic features of adult overwhelming meningococcal purpura and to examine the prognostic factors by multivariate analysis at the time of admission to the intensive care unit. Thirty-five patients (≥13 years of age) with meningococcal infection, circulatory shock, and generalized purpuric lesions of abrupt onset were recorded in eight intensive care units from 1977 to 1989. The patients were young (mean age, 26.6 years; range, 13 to 68 years) and had been previously healthy. The female-to-male ratio was 3:1. Mortality was 54.3%, with most deaths occurring within the first 48 hours, usually secondary to irreversible shock with multiple organ failure. Ischemic complications (eight cases), prolonged heart failure (seven cases), and secondary septicemia (five cases) were the chief complications among survivors. Initial hemodynamic study after volume loading showed low stroke volume index (mean ± SD, 29.4 ±13 mL/m 2 ) and tachycardia (mean ± SD, 138 ± 16 beats per minute), a profile suggesting a greater myocardial depression than usually observed in gram-negative bacillary septic shock. Univariate prognostic analysis showed that four variables at the time of admission were associated with fatal outcome: a plasma fibrinogen level of 1.5 g/L or less, a factor V concentration of 0.20 or less, a platelet count lower than 80 × 10 9 /L, and a cerebrospinal fluid leukocyte count of 20 × 10 6 /L or less. Stepwise regression analysis showed that low fibrinogen level (≤1.5 g/L) was the sole adverse prognostic variable (odds ratio = 2, 95% confidence interval, 1.5 to 2.7). Adult overwhelming meningococcal purpura is still associated with high mortality and morbidity. Low fibrinogen level at time of admission may permit early recognition of the most severely ill patients. ( Arch Intern Med. 1991;151:310-316)

Adult overwhelming meningococcal purpura. A study of 35 cases, 1977-1989.

Many animal studies have attempted to simulate the circulatory responses to Gram-negative septicemia (iv infusion of live bacteria, fecal inoculation into body cavities, and administration of purified endotoxins by various routes), but the contribution of the heart to the adverse hemodynamic derangements and thus to the pathogenesis of shock is difficult to determine because of peripheral vascular events that influence cardiac performance. When blood pools in the periphery, venous return decreases and cardiac output can decrease without a primary myocardial defect being present. However, early heart dysfunction has been recognized in sepsis. Hemodynamic monitoring has not reduced overall mortality, but it has been helpful in guiding fluid administration and evaluating response to vasopressor therapy.

Heart failure in septic shock: effects of inotropic support.

To evaluate, in right ventricular (RV) myocardial infarction, the role of tricuspid regurgitation (TR) and left ventricular (LV) damage and the response to treatment of low cardiac output, 20 patients were prospectively studied. Volume infusion increased cardiac output only slightly (11%, p less than 0.001), despite a dramatic increase in ventricular filling pressures. Dobutamine (4 micrograms.kg-1.min-1) markedly increased cardiac output (24%, p less than 0.001) with a decrease in ventricular filling pressures. In the 5 patients with TR, dobutamine only modestly increased cardiac output (9 vs 26%, p less than 0.001), while stroke index and LV end-diastolic dimensions decreased in comparison (-5 vs 33% and -6 vs 9%, respectively, p less than 0.001). In the absence of TR (n = 15), there was no significant difference in response to volume expansion between patients with normal (n = 7) and depressed LV ejection fraction (n = 8). In contrast, dobutamine, in patients with depressed LV function, induced a greater increase in cardiac output (38 vs 17%, p less than 0.01) and RV ejection fraction (36 vs 12%, p less than 0.05). All patients with RV infarction-induced low cardiac output responded only modestly to volume loading. Dobutamine is particularly efficacious in patients without TR who have depressed LV function by improving RV function and, consequently, LV preload. In the 5 patients with TR, increasing RV contractility failed to improve the forward stroke volume by increasing the regurgitant fraction.

Bruno Schremmer

Papers

Adult overwhelming meningococcal purpura. A study of 35 cases, 1977-1989.

Heart failure in septic shock: effects of inotropic support.

Role of tricuspid regurgitation and left ventricular damage in the treatment of right ventricular infarction-induced low cardiac output syndrome

Value of elementary, combined, and modeled hemodynamic variables

Computer Assistance for Hemodynamic Evaluation