Early Fluid Resuscitation

Solid evidence exists that fluid therapy must be started as a first-line treatment in all patients with septic shock as soon as hypotension is detected, with the goal of rapidly restoring tissue perfusion. Crystalloids or colloids can be used for initial fluid therapy, and albumin should be reserved for patients with patent or supposed hypoalbuminemia. Once fluid administration is started, its effect must be carefully monitored. In the early stages, appropriate monitoring should ensure that fluid resuscitation actually increases cardiac preload, mean arterial pressure, and tissue oxygenation. In later stages, monitoring should help to avoid fluid overload. For this purpose, the end-point of fluid therapy should not be the static values of preload indicators, but rather the disappearance of indicators of preload responsiveness. Finally, the risk of fluid overload must always be kept in mind, especially in case of lung injury.     

A 2-µm Continuous-Wave Laser System for Safe and High-Precision Dissection During NOTES Procedures

Introduction

Lasers 2-µm in wavelength offer efficient tissue cutting with limited thermal damage in biological tissue.

Objective

To evaluate the dissection capabilities of a 2-μm continuous-wave laser for NOTES procedures.

Methods and Procedures

We conducted 18 acute animal experiments. Group 1 (three animals): transcolonic access to the peritoneal cavity (15-W transcolonic laser puncture, balloon dilation over the laser probe). Group 2 (six animals): transcolonic access with needle-knife puncture and balloon dilation. Group 3 (three animals): transgastric access to the peritoneal cavity (similar technique as group 1) followed by laser-assisted dissection of the kidney. In one animal of group 3, a therapeutic target (hematoma) was created by percutaneous puncture of the kidney. Group 4 (six animals): transgastric access (similar to the technique of group 2).

Results

Translumenal access to the peritoneal cavity was achieved in 2–3 min in group 1 (significantly shorter than with the needle-knife-assisted technique, 4–5 min, p = 0.02) and in 7–10 min in group 3 (compared to 6–17 min in group 4, p = 0.88). In group 3, laser dissection of the parietal peritoneum and of perinephric connective tissue allowed access to the retroperitoneum with complete removal of a blood collection in the animal with puncture trauma. Laser dissection demonstrated good maneuverability, clean and rapid cutting, and excellent hemostasis. Peritoneoscopy and necropsy showed no damage of targeted tissue and surrounding organs.

Conclusions

The 2-μm continuous-wave laser system showed promising capabilities for highly precise and safe dissection during NOTES procedures.     

Quality assessment of clinical practice guidelines for the prescription of antidepressant drugs during pregnancy

Antidepressant use during the gestational period remains a controversial issue. The objective of this study was to appraise the quality of the available clinical practice guidelines (CPGs) that includes recommendations for antidepressant use during pregnancy. We systematically searched for documents published between January 2000 and September 2010 in MEDLINE / TRIP database and on clearing houses and main scientific societies' websites. Four appraisers evaluated each guideline using the Appraisal of Guidelines for Research and Evaluation tool (AGREE II). Intra-class correlation coefficients (ICC) with 95% confidence intervals (CI) were calculated as an overall indicator of agreement. Twelve CPGs were included from a total of 539 references. Only two guidelines were specifically addressed to pregnant women. The overall agreement among reviewers was high (ICC: 0.94, 95% CI: 0.86-0.98). The mean scores and standard deviation (SD) for each of the AGREE II domains were: scope and purpose: 84.4% (12); stakeholder involvement: 67.4% (29.8); rigor of development: 68.6% (19.8); clarity and presentation: 83.4% (17.4); applicability: 44% (37.3); and editorial independence: 62.1% (30.4). After standardizing the scores of the 12 guidelines, 5 were considered as being "recommended", 5 as "recommended with modifications, and 2 as "not recommended". Among the five recommended guidelines, two were specifically conceived to the gestational period. CPGs containing recommendations for antidepressant use during pregnancy were of moderate to high quality. Future guidelines should take into account the observed drawbacks in some domains, and specifically focus a more in depth approach of depression during pregnancy.     

Assessment of RTG-W1, RTL-W1, and PLHC-1 fish cell lines for genotoxicity testing of environmental pollutants by means of a Fpg-modified comet assay

In a context of growing awareness of aquatic pollution impacts, there is an increasing need to develop methods for hazard and risk assessment of pollutants. For this purpose, in vitro models such as fish cell lines warrant to be evaluated as possible alternative to in vivo fish testing, and new toxicity endpoints such as genotoxicity deserve to be considered. This study assesses the interest of the formamido pyrimidine glycosylase (Fpg)-modified comet assay applied to three fish cell lines (RTL-W1, RTG-W1, and PLHC-1) regarding the sensitivity of the system for measuring genotoxicity of various classes of pollutants. Cytochrome P450-dependent EROD activity has also been measured to evaluate the importance of the biotransformation capacity of the cell lines in genotoxicity assessment. For all cell lines and chemicals tested, a concentration dependent genotoxic effect was observed with a 10- to 1000-fold increased sensitivity when using the Fpg-protocol compared to the standard comet assay. Such a modified assay led in particular to improve the detection threshold of oxidative and alkylating DNA damages following exposure at environmentally relevant contaminant concentrations and could partly compensate for the lower sensitivity of cell lines versus whole organism testing often cited as a limit of in vitro testing.     

Use of polar organic chemical integrative samplers to assess the effects of chronic pesticide exposure on biofilms

The responses of aquatic organisms to chronic exposure to environmental concentrations of toxicants, often found in mixtures, are poorly documented. Here passive sampler extracts were used in experimental contamination of laboratory channels, to investigate their effects on natural biofilm communities. A realistic mixture of pesticides extracted from Polar Organic Chemical Integrative Samplers was used to expose biofilms in laboratory channels to total pesticide concentrations averaging 0.5 ± 0.1 μg l^?1. The level of exposure was representative of field conditions in terms of relative proportions of the substances but the exposure concentration was not maintained (decreasing concentrations between contamination occasions). The impact on the structural as well as the functional characteristics of the autotrophic and heterotrophic components was determined, using biofilm grown in uncontaminated conditions (reference site) and in sites exposed to pesticides (contaminated site). The exposure imposed did not significantly modify the structure or functions of reference biofilms, nor did it modify tolerance as measured by mixture EC₅₀ (EC₅₀ mix). In contrast, the communities from the more contaminated downstream section lost tolerance following decreased dose exposure, but community composition remained fairly stable. Overall, these results indicate that low levels of contamination did not lead to strong changes in community structure, and 14-day changes in tolerance seemed to depend mainly on physiological adaptation, suggesting that other environmental factors or longer-lasting processes prevailed. This study reports the first attempt to use passive sampler extracts as a realistic composite contaminant for experimental exposure of biofilms, with promising perspectives in further ecotoxicology studies.