Echinocandins Accelerate Particle Transport Velocity in the Murine Tracheal Epithelium: Dependency on Intracellular Ca2+ Stores.

The mucociliary clearance of lower airways is modulated by different physiologic stimuli and also by pathophysiologic agents like polluting substances or pharmaceutical molecules. In the present investigation, we measured the particle transport velocity (PTV) of mouse tracheae as a surrogate for mucociliary clearance. In mouse tracheal preparations, we detected a sustained increase in the PTV under the application of the echinocandins caspofungin, anidulafungin, and micafungin. In further experiments, we observed the effects of echinocandins on the PTV were dependent on intracellular Ca2+ homeostasis. In Ca2+-free buffer solutions, the amplitude of the echinocandin-evoked rise in the PTV was significantly reduced relative to that in the experiments in Ca2+-containing solutions. Depletion of intracellular Ca2+ stores of the endoplasmic reticulum (ER) by caffeine completely prevented an increase in the PTV with subsequent caspofungin applications. Mitochondrial Ca2+ stores seemed to be unaffected by echinocandin treatment. We also observed no altered generation of reactive oxygen species under the application of echinocandins as probable mediators of the PTV. Consequently, the observed echinocandin effects on the PTV depend upon the Ca2+ influx and Ca2+ contents of the ER. We assume that all three echinocandins act intracellularly on ER Ca2+ stores to activate Ca2+-dependent signal transduction cascades, enhancing the PTV.

Caspofungin Modulates Ryanodine Receptor-Mediated Calcium Release in Human Cardiac Myocytes.

Recent studies showed that critically ill patients might be at risk for hemodynamic impairment during caspofungin (CAS) therapy. The aim of our present study was to examine the mechanisms behind CAS-induced cardiac alterations. We revealed a dose-dependent increase in intracellular Ca2+ concentration ([Ca2+]i) after CAS treatment. Ca2+ ions were found to be released from intracellular caffeine-sensitive stores, most probably via the activation of ryanodine receptors.

Cardiac Effects of Echinocandins in Endotoxemic Rats.

Echinocandins are known as effective and safe agents for the prophylaxis and treatment of different cohorts of patients with fungal infections. Recent studies revealed that certain pharmacokinetics of echinocandin antifungals might impact clinical efficacy and safety in special patient populations. The aim of our study was to evaluate echinocandin-induced aggravation of cardiac impairment in septic shock. Using an in vivo endotoxemic shock model in rats, we assessed hemodynamic parameters and time to hemodynamic failure (THF) after additional central-venous application of anidulafungin (2.5 mg/kg of body weight [BW]), caspofungin (0.875 mg/kg BW), micafungin (3 mg/kg BW), and control (0.9% sodium chloride). In addition, echinocandin-induced cytotoxicity was evaluated in isolated rat cardiac myocytes. THF of the animals in the caspofungin group (n = 7) was significantly reduced compared to that in the control (n = 6) (136 min versus 180 min; P = 0.0209). The anidulafungin group (n = 7) also showed a trend of reduced THF (136 min versus 180 min; log-rank test P = 0.0578). Animals in the micafungin group (n = 7) did not show significant differences in THF compared to those in the control. Control group animals and also micafungin group animals did not show altered cardiac output (CO) during our experiments. In contrast, administration of anidulafungin or caspofungin induced a decrease in CO. We also revealed a dose-dependent increase of cytotoxicity in anidulafungin- and caspofungin-treated cardiac myocytes. Treatment with micafungin did not cause significantly increased cytotoxicity. Further studies are needed to explore the underlying mechanism.

Cardiac effects of echinocandins after central venous administration in adult rats.

Echinocandins have become the agents of choice for early and specific antifungal treatment in critically ill patients. In vitro studies and clinical case reports revealed a possible impact of echinocandin treatment on cardiac function. The aim of our study was to evaluate echinocandin-induced cardiac failure. Using an in vivo rat model, we assessed hemodynamic parameters and time to hemodynamic failure after central venous application (vena jugularis interna) of anidulafungin (low-dose group, 2.5 mg/kg body weight [BW]; high-dose group, 25 mg/kg BW), caspofungin (low-dose group, 0.875 mg/kg BW; high-dose group, 8.75 mg/kg BW), micafungin (low-dose group, 3 mg/kg BW; high-dose group, 30 mg/kg BW), and placebo (0.9% sodium chloride). Left ventricular heart tissue was collected to determine mitochondrial enzyme activity via spectrophotometric measurements. mRNA expression of transcriptional regulators and primary mitochondrial transcripts, mitochondrial DNA (mtDNA) content, and citrate synthase activity were also explored. Animals receiving high-dose anidulafungin or caspofungin showed an immediate decrease in hemodynamic function. All of the subjects in these groups died during the observation period. Every animal in the untreated control group survived (P < 0.001). Hemodynamic failure was not noticed in the anidulafungin and caspofungin low-dose groups. Micafungin had no impact on cardiac function. In analyzing mitochondrial enzyme activity and mitochondrial transcripts, we found no association between echinocandin administration and the risk for hemodynamic failure. Further experimental studies are needed to elucidate the underlying mechanisms involved in cardiotoxic echinocandin effects. In addition, randomized controlled clinical trials are needed to explore the clinical impact of echinocandin treatment in critically ill patients.

Sepsis varies arterial two-pore-domain potassium channel messenger RNA in mice.

BACKGROUND: Hemodynamic changes are mainly responsible for organ failure and subsequently for the poor outcome of sepsis. Occurring macro- and micro-circulatory dysfunctions are not homogeneously distributed in the vessel beds. Especially mesenteric arterioles are subject to hypoperfusion during sepsis, and in consequence, a dysfunction of the downstream organs develops. Furthermore, impaired perfusion of the splanchnic area may cause intestinal barrier breakdown supporting the translocation of bacteria or toxins into the circulation aggravating a systemic infection and organ failure. The two-pore potassium channels (K2P channels) are responsible for setting the resting membrane potential of smooth muscle cells. Because of their sensitivity by various metabolic or humoral mediators, which are also varying during inflammatory processes, they can determine vascular resistance during sepsis. Dopamine receptors type 1 (D1R) and 2 (D2R) are assumed to be involved in the regulation of arterial tone under hypoxic conditions and are investigated too. MATERIALS AND METHODS: Sepsis was induced in mice by the cecal ligation and puncture model. This study investigates the expression of K2P channels and the dopamine receptors at RNA level by real-time polymerase chain reaction analysis and two K2P channels at the protein level by Western blotting. RESULTS: The RNA levels of K2P channels respond differently to sepsis. Although the weakly inward rectifying K+ channel 2 (TWIK 2) is not affected, TWIK-related acid-sensitive K+ channel 1 and 2 (TASK 1 and TASK 2) and TWIK-related K+ channel 1 (TREK 1) are partially downregulated during the course of the experiment. A downregulation of D1R and an upregulation of the D2R could be observed during the septic phase. CONCLUSIONS: The changes shown could be important factors for the reduced mesenteric perfusion during sepsis.

Intrinsic vascular dopamine - a key modulator of hypoxia-induced vasodilatation in splanchnic vessels.

Dopamine not only is a precursor of the catecholamines noradrenaline and adrenaline but also serves as an independent neurotransmitter and paracrine hormone. It plays an important role in the pathogenesis of hypertension and is a potent vasodilator in many mammalian systemic arteries, strongly suggesting an endogenous source of dopamine in the vascular wall. Here we demonstrated dopamine, noradrenaline and adrenaline in rat aorta and superior mesenteric arteries (SMA) by radioimmunoassay. Chemical sympathectomy with 6-hydroxydopamine showed a significant reduction of noradrenaline and adrenaline, while dopamine levels remained unaffected. Isolated endothelial cells were able to synthesize and release dopamine upon cAMP stimulation. Consistent with these data, mRNAs coding for catecholamine synthesizing enzymes, i.e. tyrosine hydroxylase (TH), aromatic l-amino acid decarboxylase, and dopamine-ß-hydroxylase were detected by RT-PCR in cultured endothelial cells from SMA. TH protein was detected by immunohistochemisty and Western blot. Exposure of endothelial cells to hypoxia (1% O2) increased TH mRNA. Vascular smooth muscle cells partially expressed catecholaminergic traits. A physiological role of endogenous vascular dopamine was shown in SMA, where D1 dopamine receptor blockade abrogated hypoxic vasodilatation. Experiments on SMA with endothelial denudation revealed a significant contribution of the endothelium, although subendothelial dopamine release dominated. From these results we conclude that endothelial cells and cells of the underlying vascular wall synthesize and release dopamine in an oxygen-regulated manner. In the splanchnic vasculature, this intrinsic non-neuronal dopamine is the dominating vasodilator released upon lowering of oxygen tension.

Loss of vagal tone aggravates systemic inflammation and cardiac impairment in endotoxemic rats.

BACKGROUND: During the course of sepsis, often myocardial depression with hemodynamic impairment occurs. Acetylcholine, the main transmitter of the parasympathetic Nervus vagus, has been shown to be of importance for the transmission of signals within the immune system and also for a variety of other functions throughout the organism. Hypothesizing a potential correlation between this dysfunction and hemodynamic impairment, we wanted to assess the impact of vagal stimulation on myocardial inflammation and function in a rat model of lipopolysaccharide (LPS)-induced septic shock. As the myocardial tissue is (sparsely) innervated by the N. vagus, there might be an important anti-inflammatory effect in the heart, inhibiting proinflammatory gene expression in cardiomyocytes and improving cardiac function. MATERIALS AND METHODS: We performed stimulation of the right cervical branch of the N. vagus in vagotomized, endotoxemic (1 mg/kg body weight LPS, intravenously) rats. Hemodynamic parameters were assessed over time using a left ventricular pressure-volume catheter. After the experiments, hearts and blood plasma were collected, and the expression of proinflammatory cytokines was measured using quantitative reverse transcription polymerase chain reaction and enzyme-linked immunosorbent assay. RESULTS: After vagotomy, the inflammatory response was aggravated, measurable by elevated cytokine levels in plasma and ventricular tissue. In concordance, cardiac impairment during septic shock was pronounced in these animals. To reverse both hemodynamic and immunologic effects of diminished vagal tone, even a brief stimulation of the N. vagus was enough during initial LPS infusion. CONCLUSIONS: Overall, the N. vagus might play a major role in maintaining hemodynamic stability and cardiac immune homeostasis during septic shock.

Dopamine, norepinephrine, and vasopressin accelerate particle transport velocity in murine tracheal epithelium via substance-specific receptor pathways: dependency on intra- and extracellular Ca2+ sources.

Background: The unique ability of the respiratory tract to protect the integrity of the airways by removing potentially harmful substances is defined as mucociliary clearance. This complex physiological mechanism protects the lower airways by ridding them of pollutants and pathogens. This study aimed to evaluate the potential influence of clinically relevant vasopressors on mucociliary clearance. Material and methods: The particle transport velocity (PTV) of isolated murine tracheae was measured as a surrogate for mucociliary clearance under the influence of dopamine, norepinephrine, and vasopressin. Inhibitory substances were applied to elucidate relevant signal transduction cascades and the value and origin of calcium ions. Reverse-transcription polymerase chain reactions (RT-PCR) were performed to identify the expression of vasopressin receptor subtypes. Results: Dopamine, norepinephrine, and vasopressin significantly increased the PTV in a dose-dependent manner with half maximal effective concentrations of 0.58 µM, 1.21 µM, and 0.10 µM, respectively. Each substance increased the PTV via separate receptor pathways. While dopamine acted on D1-like receptors to increase the PTV, norepinephrine acted on ß-adrenergic receptors, and vasopressin acted on V1a receptors. RT-PCR revealed the expression of V1a in the murine whole trachea and tracheal epithelium. PTV increased when protein kinase A was inhibited and norepinephrine or vasopressin were applied, but not when dopamine was applied. Phospholipase C inhibition decreased the PTV when vasopressin was applied. In general, maximum PTV was significantly reduced when extracellular calcium entry was inhibited. When intracellular calcium stores were depleted, no increase in PTV was observed after administering all three substances. Inositol trisphosphate receptor activation was found to be pivotal in the increase in murine PTV after applying dopamine and vasopressin. Discussion: Dopamine, norepinephrine, and vasopressin accelerate the murine PTV via substance-specific receptor pathways. Further investigations should assess the value and interaction of these substances on mucociliary clearance in clinical practice.

A 20:1 synergetic mixture of cafedrine/theodrenaline accelerates particle transport velocity in murine tracheal epithelium via IP3 receptor-associated calcium release.

Background: Mucociliary clearance is a pivotal physiological mechanism that protects the lung by ridding the lower airways of pollution and colonization by pathogens, thereby preventing infections. The fixed 20:1 combination of cafedrine and theodrenaline has been used to treat perioperative hypotension or hypotensive states due to emergency situations since the 1960s. Because mucociliary clearance is impaired during mechanical ventilation and critical illness, the present study aimed to evaluate the influence of cafedrine/theodrenaline on mucociliary clearance. Material and Methods: The particle transport velocity (PTV) of murine trachea preparations was measured as a surrogate for mucociliary clearance under the influence of cafedrine/theodrenaline, cafedrine alone, and theodrenaline alone. Inhibitory substances were applied to elucidate relevant signal transduction cascades. Results: All three applications of the combination of cafedrine/theodrenaline, cafedrine alone, or theodrenaline alone induced a sharp increase in PTV in a concentration-dependent manner with median effective concentrations of 0.46 µM (consisting of 9.6 µM cafedrine and 0.46 µM theodrenaline), 408 and 4 µM, respectively. The signal transduction cascades were similar for the effects of both cafedrine and theodrenaline at the murine respiratory epithelium. While PTV remained at its baseline value after non-selective inhibition of ß-adrenergic receptors and selective inhibition of ß1 receptors, cafedrine/theodrenaline, cafedrine alone, or theodrenaline alone increased PTV despite the inhibition of the protein kinase A. However, IP3 receptor activation was found to be the pivotal mechanism leading to the increase in murine PTV, which was abolished when IP3 receptors were inhibited. Depleting intracellular calcium stores with caffeine confirmed calcium as another crucial messenger altering the PTV after the application of cafedrine/theodrenaline. Discussion: Cafedrine/theodrenaline, cafedrine alone, and theodrenaline alone exert their effects via IP3 receptor-associated calcium release that is ultimately triggered by ß1-adrenergic receptor stimulation. Synergistic effects at the ß1-adrenergic receptor are highly relevant to alter the PTV of the respiratory epithelium at clinically relevant concentrations. Further investigations are needed to assess the value of cafedrine/theodrenaline-mediated alterations in mucociliary function in clinical practice.

A fixed 20:1 combination of cafedrine/theodrenaline increases cytosolic Ca2+ concentration in human tracheal epithelial cells via ryanodine receptor-mediated Ca2+ release.

Mucociliary clearance is a pivotal physiological mechanism that protects the lung by cleaning the airways from pollution and colonization, thereby preventing infection. Ciliary function is influenced by various signal transduction cascades, and Ca2+ represents a key second messenger. A fixed 20:1 combination of cafedrine and theodrenaline has been widely used to treat perioperative hypotension and emergency hypotensive states since the 1960s; however, its effect on the intracellular Ca2+ concentration ([Ca2+]i) of respiratory epithelium remains unknown. Therefore, human tracheal epithelial cells were exposed to the clinically applied 20:1 mixture of cafedrine/theodrenaline and the individual substances separately. [Ca2+]i was assessed by FURA-2 340/380 fluorescence ratio. Pharmacological inhibitors were applied to elucidate relevant signal transduction cascades, and reverse transcription polymerase chain reaction (RT-PCR) was performed on murine tracheal epithelium to analyze ryanodine receptor (RyR) subtype expression. All three pharmacological preparations instantaneously induced a steep increase in [Ca2+]i that quickly returned to its baseline value despite the persistence of each substance. Peak [Ca2+]i following the administration of 20:1 cafedrine/theodrenaline, cafedrine alone, and theodrenaline alone increased in a dose-dependent manner, with median effective concentrations of 0.35 mM (7.32 mM cafedrine and 0.35 mM theodrenaline), 3.14 mM, and 3.45 mM, respectively. When extracellular Ca2+ influx was inhibited using a Ca2+-free buffer solution, the peak [Ca2+]i following the administration of cafedrine alone and theodrenaline alone were reduced but not abolished. No alteration in [Ca2+]i compared with baseline [Ca2+]i was observed during ß-adrenergic receptor inhibition. Depletion of caffeine-sensitive stores and inhibition of RyR, but not IP3 receptors, completely abolished any increase in [Ca2+]i. However, [Ca2+]i still increased following the depletion of mitochondrial Ca2+ stores using 2,4-dinitrophenol. RT-PCR revealed RyR-2 and RyR-3 expression on murine tracheal epithelium. Although our experiments showed that cafedrine/theodrenaline, cafedrine alone, or theodrenaline alone release Ca2+ from intracellular stores through mechanisms that are exclusively triggered by ß-adrenergic receptor stimulation, which most probably lead to RyR activation, clinical plasma concentrations are considerably lower than those used in our experiments to elicit an increase in [Ca2+]i; therefore, further studies are needed to evaluate the ability of cafedrine/theodrenaline to alter mucociliary clearance in clinical practice.

Small cause - big effect: improvement in interface design results in improved data quality - a multicenter crossover study.

In Germany the core data set for anesthesia version 3.0 was recently introduced for external quality assurance, which includes five surgical tracer procedures. We found a low rate of correctly documented tracers when compared to procedure data (OPS-Codes) documented separately. Examination revealed that the graphical user interface (GUI) contravened the dialogue principles as defined in EN ISO 9241-110. We worked with the manufacturer to implement small improvements and roll out the software. A crossover study was conducted at a university hospital and a municipal hospital chain with five hospitals. All study sites and surgical tracer procedures combined, we found an improvement from 42% to 65% (p<0.001; N=34,610) correctly documented anesthesias. We also saw improvements for most of the observed surgical tracer procedures at all hospitals. Our results show the big effect small changes to the GUI can have on data quality. They also raise the question, if highly flexible and parameterized clinical documentation systems are suited to achieve high usability. Finding the right balance between GUIs designed by usability experts and the flexibility of parameterization by administrators will be a difficult task for the future and subject to further research.

Sepsis and major abdominal surgery lead to flaking of the endothelial glycocalix.

BACKGROUND: Recent evidence suggests that the endothelial glycocalix plays an important role in lethal outcomes following sepsis. We therefore tested if the endothelial glycocalix is shed in patients with sepsis compared with patients after major abdominal surgery and healthy volunteers. MATERIAL AND METHODS: A total of 150 individuals were tested for levels of inflammatory markers (intercellular adhesion molecule-1 [ICAM-1], vascular cell adhesion molecule-1 [VCAM-1], interleukin-6 [IL-6]) and glycocalix markers (syndecan-1, heparan sulfate). Three groups consisted of patients with severe sepsis or septic shock, patients after major abdominal surgery without systemic inflammatory response syndrome, and healthy volunteers. Blood was drawn, at the time of diagnosis or surgery, and 6, 24, and 48h later. We correlated these markers to each other and to clinically used inflammation markers. RESULTS: Levels of inflammatory markers were markedly higher in patients with sepsis compared with patients after major abdominal surgery and healthy volunteers. After major abdominal surgery, glycocalix markers in human plasma were at levels comparable to patients with sepsis. In patients with sepsis, levels of IL-6 correlated with syndecan-1, ICAM-1, VCAM-1, and lactate, while ICAM-1 furthermore correlated with CRP and lactate levels. CONCLUSION: High levels of glycocalix markers indicated that significant flaking of the endothelial glycocalix occurred in patients with sepsis, and to a lesser extent in patients after major abdominal surgery. This novel finding could explain the nonspecific capillary leaking syndrome of patients with sepsis and after major abdominal surgery, and may identify new targets for treating those patient populations.

Sepsis-induced degradation of endothelial glycocalix.

Sepsis, a general inflammatory response to microbiological infection, is still a major cause of high mortality rates in intensive care units. This mortality rate strongly correlates with sepsis-induced impairment of organ blood supply as a consequence of disturbed capillary circulation and vascular leakage. Within this pathophysiological process, endothelial cell function plays a key role. Recent studies provide evidence that degradation of the glycocalix on the luminal cell membrane is an early step in septic vascular endothelial cell disorder and its shed compounds, such syndecan-1, heparan sulfate, intercellular-adhesion-molecule-1 (ICAM-1), and vascular-cell-adhesion-molecule-1 (VCAM-1), can be quantified in the plasma. The plasma concentrations of heparan sulfate and syndecan-1 strongly correlate with severity of sepsis and with inflammatory markers such as interleukin-6 (IL-6). Furthermore, a nonspecific deterioration of the glycocalix occurs during major abdominal surgery and during ischemia/reperfusion after vascular surgery. Both surgical treatments cause vascular leakage and, consequently, tissue edema, similar to that triggered by inflammatory impairment of the endothelial cell barrier. So far, no specific therapeutic strategies exist to maintain glycocalix integrity; hence, conserving endothelial function. Detection of glycocalix compounds in the plasma can be utilized as diagnostic markers to evaluate sepsis-induced endothelial damage and to estimate severity of sepsis. In the future, efforts will be made to prevent glycocalix damage during sepsis or major surgery. As a result, this will possibly preserve organ function and improve patient outcome.

Caspofungin induces the release of Ca2+ ions from internal stores by activating ryanodine receptor-dependent pathways in human tracheal epithelial cells.

The antimycotic drug caspofungin is known to alter the cell function of cardiomyocytes and the cilia-bearing cells of the tracheal epithelium. The objective of this study was to investigate the homeostasis of intracellular Ca2+ concentration ([Ca2+]i) after exposure to caspofungin in isolated human tracheal epithelial cells. The [Ca2+]i was measured using the ratiometric fluoroprobe FURA-2 AM. We recorded two groups of epithelial cells with distinct responses to caspofungin exposure, which demonstrated either a rapid transient rise in [Ca2+]i or a sustained elevation of [Ca2+]i. Both patterns of Ca2+ kinetics were still observed when an influx of transmembraneous Ca2+ ions was pharmacologically inhibited. Furthermore, in extracellular buffer solutions without Ca2+ ions, caspofungin exposure still evoked this characteristic rise in [Ca2+]i. To shed light on the origin of the Ca2+ ions responsible for the elevation in [Ca2+]i we investigated the possible intracellular storage of Ca2+ ions. The depletion of mitochondrial Ca2+ stores using 25 µM 2,4-dinitrophenol (DNP) did not prevent the caspofungin-induced rise in [Ca2+]i, which was rapid and transient. However, the application of caffeine (30 mM) to discharge Ca2+ ions that were presumably stored in the endoplasmic reticulum (ER) prior to caspofungin exposure completely inhibited the caspofungin-induced changes in [Ca2+]i levels. When the ER-bound IP3 receptors were blocked by 2-APB (40 µM), we observed a delayed transient rise in [Ca2+]i as a response to the caspofungin. Inhibition of the ryanodine receptors (RyR) using 40 µM ryanodine completely prevented the caspofungin-induced elevation of [Ca2+]i. In summary, caspofungin has been shown to trigger an increase in [Ca2+]i independent from extracellular Ca2+ ions by liberating the Ca2+ ions stored in the ER, mainly via a RyR pathway.

Evaluation of pulse wave transit time analysis for non-invasive cardiac output quantification in pregnant patients.

Pregnant patients undergoing minimally-invasive foetoscopic surgery for foetal spina bifida have a need to be subjected to advanced haemodynamic monitoring. This observational study compares cardiac output as measured by transpulmonary thermodilution monitoring with the results of non-invasive estimated continuous cardiac output monitoring. Transpulmonary thermodilution-based pulse contour analysis was performed for usual anaesthetic care, while non-invasive estimated continuous cardiac output monitoring data were additionally recorded. Thirty-five patients were enrolled, resulting in 199 measurement time points. Cardiac output measurements of the non-invasive estimated continuous cardiac output monitoring showed a weak correlation with the corresponding thermodilution measurements (correlation coefficient: 0.44, R2: 0.19; non-invasive estimated continuous cardiac output: 7.4 [6.2-8.1]; thermodilution cardiac output: 8.9 [7.8-9.8]; p ≤ 0.001), while cardiac index experienced no such correlation. Furthermore, neither stroke volume nor stroke volume index correlated with the corresponding thermodilution-based data. Even though non-invasive estimated continuous cardiac output monitoring consistently underestimated the corresponding thermodilution parameters, no trend analysis was achievable. Summarizing, we cannot suggest the use of non-invasive estimated continuous cardiac output monitoring as an alternative to transpulmonary thermodilution for cardiac output monitoring in pregnant patients undergoing minimally-invasive foetoscopic surgery for spina bifida.

Hemodynamic changes in surgical intensive care unit patients undergoing echinocandin treatment.

Background Echinocandins are well-established agents for the treatment of patients with fungal infections, but growing evidence questions their safety in special patient populations prone to systemic inflammatory responses. Objective The study aimed to analyse early hemodynamic changes during echinocandin therapy in critically ill surgical patients. Setting The study was conducted at the surgical intensive care unit at the University Hospital of Giessen, Germany. Methods This single-centre retrospective study includes data from critically ill patients who underwent primary antifungal treatment during 2009-2013. Main outcome measures Hemodynamic parameters, need for vasopressor/inotropic therapy, and dose of vasopressor/inotropic therapy were recorded 2 h before and 2 h after the onset of antifungal treatment. Comparisons of echinocandins to azoles and analysis of a combined endpoint (decrease of mean arterial pressure ≥ 10 mmHg and/or new or increased dosages of norepinephrine, epinephrine, or dobutamine) were performed. Results We found 342 episodes of intravenous antifungal treatment (33 [9.6%] anidulafungin, 116 [33.9%] caspofungin, 132 [38.6%] fluconazole, 17 [5%] micafungin, 44 [12.9%] voriconazole). Group comparisons revealed no significant differences of hemodynamic parameters, need for vasopressor/inotropic therapy, and dose of vasopressor/inotropic therapy, expect for a decreased dose of norepinephrine in the fluconazole group (p < 0.001). The combined endpoint occurred in 58 (50%) caspofungin-, 16 (48.5%) anidulafungin-, 4 (23.5%) micafungin-, 23 (17.4%) fluconazole-, and 15 (34.1%) voriconazole treatment episodes. Secondary analysis of the combined anidulafungin/caspofungin group to the azoles group (fluconazole, voriconazole) showed a significant decrease of mean arterial pressure ≥ 10 mmHg (n = 37 [25%] vs. n = 27 [15%], OR = 1.8, p = 0.04), increased use of norepinephrine (n = 38 [26%] vs. n = 12 [7%], OR = 4.7, p ≤ 0.001), increased use of dobutamine (n = 12 [8%] vs. n = 4 [2%], OR = 3.8, p = 0.02), and the combined endpoint (n = 74 [50%] vs. n = 38 [21%], OR = 3.6, p ≤ 0.001). Conclusion Our retrospective data might demonstrate clinically relevant hemodynamic-depressing effects of anidulafungin and caspofungin. Further prospective acquisition of clinical data will be necessary to evaluate their impact on hemodynamic function.

Acid-evoked Ca2+ signalling in rat sensory neurones: effects of anoxia and aglycaemia.

Ischaemia excites sensory neurones (generating pain) and promotes calcitonin gene-related peptide release from nerve endings. Acidosis is thought to play a key role in mediating excitation via the activation of proton-sensitive cation channels. In this study, we investigated the effects of acidosis upon Ca2+ signalling in sensory neurones from rat dorsal root ganglia. Both hypercapnic (pHo 6.8) and metabolic-hypercapnic (pHo 6.2) acidosis caused a biphasic increase in cytosolic calcium concentration ([Ca2+] i ). This comprised a brief Ca2+ transient (half-time approximately 30 s) caused by Ca2+ influx followed by a sustained rise in [Ca2+] i due to Ca2+ release from caffeine and cyclopiazonic acid-sensitive internal stores. Acid-evoked Ca2+ influx was unaffected by voltage-gated Ca2+-channel inhibition with nickel and acid sensing ion channel (ASIC) inhibition with amiloride but was blocked by inhibition of transient receptor potential vanilloid receptors (TRPV1) with (E)-3-(4-t-butylphenyl)-N-(2,3-dihydrobenzo[b][1,4] dioxin-6-yl)acrylamide (AMG 9810; 1 microM) and N-(4-tertiarybutylphenyl)-4-(3-cholorphyridin-2-yl) tetrahydropryazine-1(2H)-carbox-amide (BCTC; 1 microM). Combining acidosis with anoxia and aglycaemia increased the amplitude of both phases of Ca2+ elevation and prolonged the Ca2+ transient. The Ca2+ transient evoked by combined acidosis, aglycaemia and anoxia was also substantially blocked by AMG 9810 and BCTC and, to a lesser extent, by amiloride. In summary, the principle mechanisms mediating increase in [Ca2+] i in response to acidosis are a brief Ca2+ influx through TRPV1 followed by sustained Ca2+ release from internal stores. These effects are potentiated by anoxia and aglycaemia, conditions also prevalent in ischaemia. The effects of anoxia and aglycaemia are suggested to be largely due to the inhibition of Ca2+-clearance mechanisms and possible increase in the role of ASICs.

Rapid onset of amiodarone induced pulmonary toxicity after lung lobe resection - A case report and review of recent literature.

Amiodarone-induced pulmonary toxicity (APT) is a severe side effect that can lead to lung fibrosis or fatal respiratory failure. Usually APT occurs during long term therapy after administration of prolonged loading doses or high cumulative doses. We present the case of a 58 year old woman who underwent thoracic surgery with lobe resection. She developed atrial fibrillation with hemodynamic-instability on the first post-operative day. We initiated amiodarone therapy and four days later she developed respiratory failure. The pulmonary function further deteriorated showing signs of an acute respiratory distress syndrome (ARDS). We therefore started mechanical ventilation, but still the gas exchange did not improve. A computer tomography-(CT)-scan presented bilateral interstitial and alveolar infiltrations. The patient also presented with leukocytosis, elevated C-reactive protein (CRP) levels however without elevated procalcitonin (PCT) concentrations. In the tracheal secretion we only harvested foam cells, but got no evidence for pathogens causing pneumonia. We immediately started glucocorticoid therapy with prednisolone 50 mg/d for five days. Almost instantaneously the gas exchange ameliorated. We were able to wean the patient from the respirator within five days. Pulmonary infiltrations were nearly vanished in a CT-scan few days later and completely disappeared in follow up examinations. This case demonstrates a per-acute onset of APT caused by a low loading dose in association with thoracic surgery. The initiation of glucocorticoid therapy in parallel to amiodarone withdrawal led to full recovery of the patient. One should consider APT when signs of pulmonary failure occur during brief periods of amiodarone therapy especially after thoracic surgery.

Moderate hypoxia influences excitability and blocks dendrotoxin sensitive K+ currents in rat primary sensory neurones.

Hypoxia alters neuronal function and can lead to neuronal injury or death especially in the central nervous system. But little is known about the effects of hypoxia in neurones of the peripheral nervous system (PNS), which survive longer hypoxic periods. Additionally, people have experienced unpleasant sensations during ischemia which are dedicated to changes in conduction properties or changes in excitability in the PNS. However, the underlying ionic conductances in dorsal root ganglion (DRG) neurones have not been investigated in detail. Therefore we investigated the influence of moderate hypoxia (27.0 +/- 1.5 mmHg) on action potentials, excitability and ionic conductances of small neurones in a slice preparation of DRGs of young rats. The neurones responded within a few minutes non-uniformly to moderate hypoxia: changes of excitability could be assigned to decreased outward currents in most of the neurones (77%) whereas a smaller group (23%) displayed increased outward currents in Ringer solution. We were able to attribute most of the reduction in outward-current to a voltage-gated K+ current which activated at potentials positive to -50 mV and was sensitive to 50 nM alpha-dendrotoxin (DTX). Other toxins that inhibit subtypes of voltage gated K+ channels, such as margatoxin (MgTX), dendrotoxin-K (DTX-K), r-tityustoxin Kalpha (TsTX-K) and r-agitoxin (AgTX-2) failed to prevent the hypoxia induced reduction. Therefore we could not assign the hypoxia sensitive K+ current to one homomeric KV channel type in sensory neurones. Functionally this K+ current blockade might underlie the increased action potential (AP) duration in these neurones. Altogether these results, might explain the functional impairment of peripheral neurones under moderate hypoxia.