Usefulness of a clinical diagnosis of ICU-acquired paresis to predict outcome in patients with SIRS and acute respiratory failure

Neuromuscular abnormalities are common in ICU patients. We aimed to assess the incidence of clinically diagnosed ICU-acquired paresis (ICUAP) and its impact on outcome.

Effects of TLR agonists on the hypoxia-regulated transcription factor HIF-1alpha and dendritic cell maturation under normoxic conditions

Dendritic cells (DC) are professional antigen presenting cells that represent an important link between innate and adaptive immunity. Danger signals such as toll-like receptor (TLR) agonists induce maturation of DC leading to a T-cell mediated adaptive immune response. In this study, we show that exogenous as well as endogenous inflammatory stimuli for TLR4 and TLR2 induce the expression of HIF-1alpha in human monocyte-derived DC under normoxic conditions. On the functional level, inhibition of HIF-1alpha using chetomin (CTM), YC-1 and digoxin lead to no consistent effect on MoDC maturation, or cytokine secretion despite having the common effect of blocking HIF-1alpha stabilization or activity through different mechanisms. Stabilization of HIF-1alpha protein by hypoxia or CoCl(2) did not result in maturation of human DC. In addition, we could show that TLR stimulation resulted in an increase of HIF-1alpha controlled VEGF secretion. These results show that stimulation of human MoDC with exogenous as well as endogenous TLR agonists induces the expression of HIF-1alpha in a time-dependent manner. Hypoxia alone does not induce maturation of DC, but is able to augment maturation after TLR ligation. Current evidence suggests that different target genes may be affected by HIF-1alpha under normoxic conditions with physiological roles that differ from those induced by hypoxia.

Muscle membrane dysfunction in critical illness myopathy assessed by velocity recovery cycles

To test the hypothesis that muscle fibers are depolarized in patients with critical illness myopathy by measuring velocity recovery cycles (VRCs) of muscle action potentials.

Effects of lung recruitment maneuvers on splanchnic organ perfusion during endotoxin-induced pulmonary arterial hypertension

Lung recruitment maneuvers (RMs), used to reopen atelectatic lung units and to improve oxygenation during mechanical ventilation, may result in hemodynamic impairment. We hypothesize that pulmonary arterial hypertension aggravates the consequences of RMs in the splanchnic circulation. Twelve anesthetized pigs underwent laparotomy and prolonged postoperative ventilation. Systemic, regional, and organ blood flows were monitored. After 6 h (= baseline), a recruitment maneuver was performed with sustained inflation of the lungs. Thereafter, the pigs were randomly assigned to group C (control, n = 6) or group E with endotoxin-induced pulmonary arterial hypertension (n = 6). Endotoxemia resulted in a normotensive and hyperdynamic state and a deterioration of the oxygenation index by 33%. The RM was then repeated in both groups. Pulmonary artery pressure increased during lipopolysaccharide infusion from 17 ± 2 mmHg (mean ± SD) to 31 ± 10 mmHg and remained unchanged in controls (P < 0.05). During endotoxemia, RM decreased aortic pulse pressure from 37 ± 14 mmHg to 27 ± 13 mmHg (mean ± SD, P = 0.024). The blood flows of the renal artery, hepatic artery, celiac trunk, superior mesenteric artery, and portal vein decreased to 71% ± 21%, 69% ± 20%, 76% ± 16%, 79% ± 18%, and 81% ± 12%, respectively, of baseline flows before RM (P < 0.05 all). Organ perfusion of kidney cortex, kidney medulla, liver, and jejunal mucosa in group E decreased to 65% ± 19%, 77% ± 13%, 66% ± 26%, and 71% ± 12%, respectively, of baseline flows (P < 0.05 all). The corresponding recovery to at least 90% of baseline regional blood flow and organ perfusion lasted 1 to 5 min. Importantly, the decreases in regional blood flows and organ perfusion and the time to recovery of these flows did not differ from the controls. In conclusion, lipopolysaccharide-induced pulmonary arterial hypertension does not aggravate the RM-induced significant but short-lasting decreases in systemic, regional, and organ blood flows.

Splanchnic vasoregulation after major abdominal surgery in pigs

Unrecognized reduction of blood supply to intestinal organs is associated with significant postoperative morbidity in abdominal surgery. The aim of this study was to determine whether--in the absence of hypovolemia--intestinal hypoperfusion as a result of blood flow redistribution occurs after abdominal surgery.

Effect of site of lactate infusion on regional lactate exchange in pigs

The rate of extra-hepatic lactate production and the route of influx of lactate to the liver may influence both hepatic and extra-hepatic lactate exchange. We assessed the dose-response of hepatic and extra-hepatic lactate exchange during portal and central venous lactate infusion.

Pulse-pressure variation and hemodynamic response in patients with elevated pulmonary artery pressure: a clinical study

Pulse-pressure variation (PPV) due to increased right ventricular afterload and dysfunction may misleadingly suggest volume responsiveness. We aimed to assess prediction of volume responsiveness with PPV in patients with increased pulmonary artery pressure.

Physiologic response to changing positive end-expiratory pressure during neurally adjusted ventilatory assist in sedated, critically ill adults

Neurally adjusted ventilatory assist (NAVA) delivers airway pressure (Paw) in proportion to neural inspiratory drive as reflected by electrical activity of the diaphragm (EAdi). Changing positive end-expiratory pressure (PEEP) impacts respiratory muscle load and function and, hence, EAdi. We aimed to evaluate how PEEP affects the breathing pattern and neuroventilatory efficiency during NAVA.

Brain herniation in a patient with apparently normal intracranial pressure: a case report

Introduction Intracranial pressure monitoring is commonly implemented in patients with neurologic injury and at high risk of developing intracranial hypertension, to detect changes in intracranial pressure in a timely manner. This enables early and potentially life-saving treatment of intracranial hypertension. Case presentation An intraparenchymal pressure probe was placed in the hemisphere contralateral to a large basal ganglia hemorrhage in a 75-year-old Caucasian man who was mechanically ventilated and sedated because of depressed consciousness. Intracranial pressures were continuously recorded and never exceeded 17 mmHg. After sedation had been stopped, our patient showed clinical signs of transtentorial brain herniation, despite apparently normal intracranial pressures (less than 10 mmHg). Computed tomography revealed that the size of the intracerebral hematoma had increased together with significant unilateral brain edema and transtentorial herniation. The contralateral hemisphere where the intraparenchymal pressure probe was placed appeared normal. Our patient underwent emergency decompressive craniotomy and was tracheotomized early, but did not completely recover. Conclusions Intraparenchymal pressure probes placed in the hemisphere contralateral to an intracerebral hematoma may dramatically underestimate intracranial pressure despite apparently normal values, even in the case of transtentorial brain herniation.

Pulse pressure variation and volume responsiveness during acutely increased pulmonary artery pressure: an experimental study

We found that pulse pressure variation (PPV) did not predict volume responsiveness in patients with increased pulmonary artery pressure. This study tests the hypothesis that PPV does not predict fluid responsiveness during an endotoxin-induced acute increase in pulmonary artery pressure and right ventricular loading.

Toll-like receptor-3-induced mitochondrial dysfunction in cultured human hepatocytes

Several studies have shown the presence of liver mitochondrial dysfunction during sepsis. TLR3 recognizes viral double-stranded RNA and host endogenous cellular mRNA released from damaged cells. TLR3 ligand amplifies the systemic hyperinflammatory response observed during sepsis and in sepsis RNA escaping from damaged tissues/cells may serve as an endogenous ligand for TLR3 thereby modulating immune responses. This study addressed the hypothesis that TLR3 might regulate mitochondrial function in cultured human hepatocytes. HepG2 cells were exposed to TLR-3 ligand (dsRNA--polyinosine-polycytidylic acid; Poly I:C) and mitochondrial respiration was measured. Poly I:C induced a reduction in maximal mitochondrial respiration of human hepatocytes which was prevented partially by preincubation with cyclosporine A (a mitochondrial permeability transition pore-opening inhibitor). Poly-I:C induced activation of NF-κB, and the mitochondrial dysfunction was accompanied by caspase-8 but not caspase-3 activation and by no major alterations in cellular or mitochondrial ultrastructure.

The association between early hemodynamic variables and outcome in normothermic comatose patients following cardiac arrest

Currently, few data exist on the association between post-cardiac arrest hemodynamic function and outcome. In this explorative, retrospective analysis, the association between hemodynamic variables during the first 24 h after intensive care unit admission and functional outcome at day 28 was evaluated in 153 normothermic comatose patients following a cardiac arrest.

Extra-intracranial blood shunt mimicking aneurysm rupture: intracranial-pressure-controlled rabbit subarachnoid hemorrhage model

The achieved degree of delayed cerebral vasospasm (DCVS) in the rabbits most frequently applied cistern magna blood injection model is often mild. The aim of this study was to characterize and evaluate the feasibility of an experimental SAH technique that mimics pathophysiological mechanisms and triggers higher degrees of DCVS.

Increasing abdominal pressure with and without PEEP: effects on intra-peritoneal, intra-organ and intra-vascular pressures

Intra-organ and intra-vascular pressures can be used to estimate intra-abdominal pressure. The aim of this prospective, interventional study was to assess the effect of PEEP on the accuracy of pressure estimation at different measurement sites in a model of increased abdominal pressure.

Comparison of non-calibrated pulse-contour analysis with continuous thermodilution for cardiac output assessment in patients with induced hypothermia after cardiac arrest

Induced mild hypothermia after cardiac arrest interferes with clinical assessment of the cardiovascular status of patients. In this situation, non-invasive cardiac output measurement could be useful. Unfortunately, arterial pulse contour is altered by temperature, and the performance of devices using arterial blood pressure contour analysis to derive cardiac output may be insufficient.