How to avoid microaspiration? A key element for the prevention of ventilator-associated pneumonia in intubated ICU patients

Microaspiration of subglottic secretions through channels formed by folds in high volume-low pressure poly-vinyl chloride cuffs of endotracheal tubes is considered a significant pathogenic mechanism of ventilator-associated pneumonia (VAP). Therefore a series of prevention measures target the avoidance of microaspiration. However, although some of these can minimize microaspiration, benefits in terms of VAP prevention are not always obvious. Polyurethane-cuffed endotracheal tubes successfully reduce microaspiration but high quality data demonstrating VAP rate reduction are lacking. An analogous conclusion can be made regarding taper-shaped cuffs compared with classic barrel-shaped cuffs. More clinical data regarding these endotracheal tube designs are needed to demonstrate clinical value in addition to in vitro-based evidence. The clinical usefulness of endotracheal tubes developed for subglottic secretions drainage is established in multiple studies and confirmed by meta-analysis. Any change in cuff design will fail to prevent microaspiration if the cuff is insufficiently inflated. At least one well-designed trial demonstrated that continuous cuff pressure monitoring and control decrease the risk of VAP. Gel lubrication of the cuff prior to intubation temporarily hampers microaspiration through sludging the channels formed by folds in high volume-low pressure cuffs. As the beneficial effect of gel lubrication is temporarily, its potential to reduce VAP risk is probably nonsignificant. A minimum positive end-expiratory pressure of at least 5 cmHO can be recommended as it reduces the risk of microaspiration in vitro and in vivo. One randomized controlled study demonstrated a reduced risk of VAP in patients ventilated with PEEP (5-8 cmHO). Regarding head-of-bed elevation, it can be recommended to avoid supine positioning. Whether a 45° head-of-bed elevation is to be preferred above 25-30° head-of-bed elevation remains unproven. Finally, the routine monitoring of gastric residual volumes in mechanically ventilated patients receiving enteral nutrition cannot be recommended

The effect of pathophysiology on pharmacokinetics in the critically ill patient — Concepts appraised by the example of antimicrobial agents

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Implementation of an evidence-based sepsis program in the intensive care unit: evident or not?

Severe sepsis and septic shock are among the most serious health conditions and are associated with unwelcome clinical, social, and economic outcomes. With the introduction of the Surviving Sepsis Campaign guidelines, the campaign leaders aimed to reduce mortality from severe sepsis by at least one quarter by 2009 by means of a six-point action plan, namely, building awareness among health care professionals, improving early and accurate disease recognition and diagnosis, increasing the use of appropriate treatments and interventions, education, getting better post-intensive care unit access, and developing standard processes of care. However, adherence to these recommendations is a first but crucial step in obtaining these goals. A comprehensive evaluation of both, adherence to a sepsis program and whether this results in better outcomes for patients, is therefore essential to guide informed decision-making regarding the implementation of such an evidence-based protocol

Visual intracortical and transthalamic pathways carry distinct information to cortical areas.

Sensory processing involves information flow between neocortical areas, assumed to rely on direct intracortical projections. However, cortical areas may also communicate indirectly via higher-order nuclei in the thalamus, such as the pulvinar or lateral posterior nucleus (LP) in the visual system of rodents. The fine-scale organization and function of these cortico-thalamo-cortical pathways remains unclear. We find that responses of mouse LP neurons projecting to higher visual areas likely derive from feedforward input from primary visual cortex (V1) combined with information from many cortical and subcortical areas, including superior colliculus. Signals from LP projections to different higher visual areas are tuned to specific features of visual stimuli and their locomotor context, distinct from the signals carried by direct intracortical projections from V1. Thus, visual transthalamic pathways are functionally specific to their cortical target, different from feedforward cortical pathways, and combine information from multiple brain regions, linking sensory signals with behavioral context

L'anémie à l'accouchement à Lomé (Togo) : prévalence, facteurs de risque et répercussions chez le nouveau-né

Une étude de prévalence réalisée à Lomé (Togo) a porté sur 125 couples mère-nouveau-né : 48% des mères et 30% des nouveaux-nés sont anémiques d'après les seuils de l'OMS. Trois mères sur quatre ont au moins un indicateur de carence en fer et celle-ci est le déterminant principal de l'anémie. Soixante huit pour cent ont une carence en folates, sans répercussion sur les paramètres hématologiques. Lorsque la carence en fer maternelle est grave (fer sérique <7umol), le fer sérique du nouveau-né est abaissé, ce qui témoigne d'une réduction de l'apport de fer au foetus. Le statut folique des nouveaux-nés est meilleur lorsque les mères ont reçu de l'acide folique pendant leur grossesse. Une supplémentation de ferro-folique systématique est donc nécessaire pendant la grossesse et serait bénéfique à la mère et à l'enfant. Les consultations prénatales devraient servir de cadre à la supplémentation. Leur fréquentation par 98% des femmes enceintes permet d'envisager une bonne couverture pour une telle intervention. (Résumé d'auteur

Intra-abdominal hypertension in patients with severe acute pancreatitis

INTRODUCTION: Abdominal compartment syndrome has been described in patients with severe acute pancreatitis, but its clinical impact remains unclear. We therefore studied patient factors associated with the development of intra-abdominal hypertension (IAH), the incidence of organ failure associated with IAH, and the effect on outcome in patients with severe acute pancreatitis (SAP). METHODS: We studied all patients admitted to the intensive care unit (ICU) because of SAP in a 4 year period. The incidence of IAH (defined as intra-abdominal pressure ≥ 15 mmHg) was recorded. The occurrence of organ dysfunction during ICU stay was recorded, as was the length of stay in the ICU and outcome. RESULTS: The analysis included 44 patients, and IAP measurements were obtained from 27 patients. IAH was found in 21 patients (78%). The maximum IAP in these patients averaged 27 mmHg. APACHE II and Ranson scores on admission were higher in patients who developed IAH. The incidence of organ dysfunction was high in patients with IAH: respiratory failure 95%, cardiovascular failure 91%, and renal failure 86%. Mortality in the patients with IAH was not significantly higher compared to patients without IAH (38% versus 16%, p = 0.63), but patients with IAH stayed significantly longer in the ICU and in the hospital. Four patients underwent abdominal decompression because of abdominal compartment syndrome, three of whom died in the early postoperative course. CONCLUSION: IAH is a frequent finding in patients admitted to the ICU because of SAP, and is associated with a high occurrence rate of organ dysfunction. Mortality is high in patients with IAH, and because the direct causal relationship between IAH and organ dysfunction is not proven in patients with SAP, surgical decompression should not routinely be performed

Haemoglobin S and haemoglobin C: 'quick but costly' versus 'slow but gratis' genetic adaptations to Plasmodium falciparum malaria

Haemoglobin S (HbS; beta 6Glu -> Val) and HbC (beta 6Glu -> Lys) strongly protect against clinical Plasmodium falciparum malaria. HbS, which is lethal in homozygosity, has a multi-foci origin and a widespread geographic distribution in sub-Saharan Africa and Asia whereas HbC, which has no obvious CC segregational load, occurs only in a small area of central West-Africa. To address this apparent paradox, we adopted two partially independent haplotypic approaches in the Mossi population of Burkina Faso where both the local S (S-Benin) and the C alleles are common (0.05 and 0.13). Here we show that: both C and S-Benin are monophyletic; C has accumulated a 4-fold higher recombinational and DNA slippage haplotypic variability than the S-Benin allele (P = 0.003) implying higher antiquity; for a long initial lag period, the C alleles did apparently remain very few. These results, consistent with epidemiological evidences, imply that the C allele has been accumulated mainly through a recessive rather than a semidominant mechanism of selection. This evidence explains the apparent paradox of the uni-epicentric geographic distribution of HbC, representing a 'slow but gratis' genetic adaptation to malaria through a transient polymorphism, compared to the polycentric 'quick but costly' adaptation through balanced polymorphism of HbS