An evidence-based recommendation on bed head elevation for mechanically ventilated patients

A semi-upright position in ventilated patients is recommended to prevent ventilator-associated pneumonia (VAP) and is one of the components in the Ventilator Bundle of the Institute for Health Care Improvement. This recommendation, however, is not an evidence-based one.status: publishe

A large retrospective assessment of voriconazole exposure in patients treated with extracorporeal membrane oxygenation

Background: Voriconazole is one of the first-line therapies for invasive pulmonary aspergillosis. Drug concentrations might be significantly influenced by the use of extracorporeal membrane oxygenation (ECMO). We aimed to assess the effect of ECMO on voriconazole exposure in a large patient population. Methods: Critically ill patients from eight centers in four countries treated with voriconazole during ECMO support were included in this retrospective study. Voriconazole concentrations were collected in a period on ECMO and before/after ECMO treatment. Multivariate analyses were performed to evaluate the effect of ECMO on voriconazole exposure and to assess the impact of possible saturation of the circuit’s binding sites over time. Results: Sixty-nine patients and 337 samples (190 during and 147 before/after ECMO) were analyzed. Subtherapeutic concentrations (<2 mg/L) were observed in 56% of the samples during ECMO and 39% without ECMO (p = 0.80). The median trough concentration, for a similar daily dose, was 2.4 (1.2–4.7) mg/L under ECMO and 2.5 (1.4–3.9) mg/L without ECMO (p = 0.58). Extensive inter-and intrasubject variability were observed. Neither ECMO nor squared day of ECMO (saturation) were retained as significant covariates on voriconazole exposure. Conclusions: No significant ECMO-effect was observed on voriconazole exposure. A large proportion of patients had voriconazole subtherapeutic concentrations

Fluid challenges in intensive care: the FENICE study A global inception cohort study

Fluid challenges (FCs) are one of the most commonly used therapies in critically ill patients and represent the cornerstone of hemodynamic management in intensive care units. There are clear benefits and harms from fluid therapy. Limited data on the indication, type, amount and rate of an FC in critically ill patients exist in the literature. The primary aim was to evaluate how physicians conduct FCs in terms of type, volume, and rate of given fluid; the secondary aim was to evaluate variables used to trigger an FC and to compare the proportion of patients receiving further fluid administration based on the response to the FC.This was an observational study conducted in ICUs around the world. Each participating unit entered a maximum of 20 patients with one FC.2213 patients were enrolled and analyzed in the study. The median [interquartile range] amount of fluid given during an FC was 500 ml (500-1000). The median time was 24 min (40-60 min), and the median rate of FC was 1000 [500-1333] ml/h. The main indication for FC was hypotension in 1211 (59 %, CI 57-61 %). In 43 % (CI 41-45 %) of the cases no hemodynamic variable was used. Static markers of preload were used in 785 of 2213 cases (36 %, CI 34-37 %). Dynamic indices of preload responsiveness were used in 483 of 2213 cases (22 %, CI 20-24 %). No safety variable for the FC was used in 72 % (CI 70-74 %) of the cases. There was no statistically significant difference in the proportion of patients who received further fluids after the FC between those with a positive, with an uncertain or with a negatively judged response.The current practice and evaluation of FC in critically ill patients are highly variable. Prediction of fluid responsiveness is not used routinely, safety limits are rarely used, and information from previous failed FCs is not always taken into account

A bifunctional sea anemone peptide with Kunitz type protease and potassium channel inhibiting properties

Sea anemone venom is a known source of interesting bioactive compounds, including peptide toxins which are invaluable tools for studying structure and function of voltage-gated potassium channels. APEKTx1 is a novel peptide isolated from the sea anemone Anthopleura elegantissima, containing 63 amino acids cross-linked by 3 disulfide bridges. Sequence alignment reveals that APEKTx1 is a new member of the type 2 sea anemone peptides targeting voltage-gated potassium channels (KVs), which also include the kalicludines from Anemonia sulcata. Similar to the kalicludines, APEKTx1 shares structural homology with both the basic pancreatic trypsin inhibitor (BPTI), a very potent Kunitz-type protease inhibitor, and dendrotoxins which are powerful blockers of voltage-gated potassium channels. In this study, APEKTx1 has been subjected to a screening on a wide range of 23 ion channels expressed in Xenopus laevis oocytes: 13 cloned voltage-gated potassium channels (KV1.1–KV1.6, KV1.1 triple mutant, KV2.1, KV3.1, KV4.2, KV4.3, hERG, the insect channel Shaker IR), 2 cloned hyperpolarization-activated cyclic nucleotide-sensitive cation non-selective channels (HCN1 and HCN2) and 8 cloned voltage-gated sodium channels (NaV1.2–NaV1.8 and the insect channel DmNaV1). Our data show that APEKTx1 selectively blocks KV1.1 channels in a very potent manner with an IC50 value of 0.9 nM. Furthermore, we compared the trypsin inhibitory activity of this toxin with BPTI. APEKTx1 inhibits trypsin with a dissociation constant of 124 nM. In conclusion, this study demonstrates that APEKTx1 has the unique feature to combine the dual functionality of a potent and selective blocker of KV1.1 channels with that of a competitive inhibitor of trypsin

Modulation of regional nitric oxide metabolism: blood glucose control or insulin?

OBJECTIVE: Tight glycaemic control by intensive insulin therapy (IIT) reduces morbidity and mortality in critically ill patients. As potential mechanisms contributing to the clinical benefits we hypothesized that glycaemic control affects regional nitric oxide (NO) bioavailability by changing NO synthases (NOS) activity, NOS transcription, NOS substrate availability or the endogenous NOS inhibitor asymmetric dimethylarginine (ADMA) levels. DESIGN: Prospective, randomized experimental study. SETTING: University medical laboratory. INTERVENTIONS: In a rabbit model of prolonged critical illness we assessed the relative impact of maintaining normal insulin/normoglycaemia (n=8), high insulin/normoglycaemia (n=8), normal insulin/hyperglycaemia (n=9) and high insulin/hyperglycaemia (n=8) plasma levels over 7 days on activity and gene expression of endothelial and inducible NOS isoforms in muscle, liver and aorta biopsies, and on plasma levels of NO, arginine and ADMA. MEASUREMENTS AND RESULTS: Compared with normoglycaemic groups, both hyperglycaemic groups revealed 53% higher day-3 NO plasma levels (p&lt;0.05), 40% lower NOS activity in muscle (p&lt;0.01) and 35% lower endothelium-mediated relaxation of aortic rings (p&lt;0.01), 515% higher gene expression of iNOS in muscle (p&lt;0.01) and 99% higher eNOS gene expression in aorta (p&lt;0.01). Only the hyperglycaemic/hyperinsulinaemic group showed lower arginine plasma levels (53% lower, p&lt;0.0001). Compared with healthy controls, normoglycaemic animals revealed 33% lower ADMA levels (p&lt;0.05). CONCLUSIONS: In this animal model of prolonged critical illness, maintaining normoglycaemia, and not glycaemia-independent actions of insulin, prevented excessive systemic NO release on day 3 and appeared to preserve local endothelial function. Factors contributing to this finding may comprise direct endothelial cell damage, direct effects on the enzyme activity, decreased substrate availability or less NO-induced inhibition.status: publishe