Impact de la nutrition sur la morbimortalité en réanimation

Critically ill patients are particularly fragile and sensitive both to under- and overfeeding, which cause infections, prolonged ventilation and overmortality. The exact definition of energy requirements is therefore extremely important; indirect calorimetry remains the only reliable tool in the clinical setting; however, it is not always applicable.     

Adaptation de la nutrition artificielle en cas d’insuffisance rénale aiguë et de recours aux techniques d’épuration extracorporelle en réanimation

Artificial nutrition management can be affected by the occurrence of acute renal failure (ARF). Indeed this organ dysfunction, which is frequent in ICU, has two main consequences: 1) metabolic disorders related either to the causal disease or to the metabolic consequences of renal failure, 2) the method used (hemofiltration and/or hemodialysis) may interfere with metabolic and nutritional consequences of this organ failure. Among various metabolic consequences, renal replacement therapy permits these ARF-patients to be provided with adequate nutritional intakes. Although replacement therapy is responsible for losses of nutrients such as glucose, aminoacids, peptides, vitamins and trace elements (lipophilic substances, which are not water-soluble, are not dialyzed), this is probably only of a minor importance. Indeed, there is almost no actual nutritional deficiency directly related to the renal replacement therapy except for hypokaliemia and hypophosphatemia, which are much more frequent during hemodialysis. The occurrence of ARF does not affect the nutritional needs as compared to similar patients without ARF. Hence recommended energy intake is 120–130 % of resting energy expenditure, or should match the actual energy expenditure whenever assessed, protein intakes should be 1.25–1.5 g/kg body weight, and the glucose/lipid ratio is close to 60 %/40 %. The needs for micronutrients and vitamins are not really modified by ARF and intakes should follow the recommended values. In the case of probable or documented deficiency (vitamins B1 and B9, selenium, zinc) intakes must be adapted. Finally the prefered route for nutritional supply must be enteral (gastric or jejunal) as generally recommended in the ICU, parenteral nutrition being reserved for real necessity.     

Stratégie d’optimisation multimodale et pluridisciplinaire de la nutrition en réanimation

The application of nutritional recommendations in the intensive care unit (ICU) is often poor. In our ICU, we developed a multidisciplinary and multimodal nutritional protocol based on knowledge transfer. The steps of the protocol are: creation of a multidisciplinary nutritional team, audit of the current practice, identification of possible obstacles to the implementation of a nutritional protocol, audit of the current expertise on nutrition, education of the ICU clinical staff, drafting of a nutritional algorithm based on international guidelines, creation of reminders and computer-aided support, assessment of the results, and maintenance of the knowledge base over time. This nutritional protocol allowed to significantly improve the nutritional support of patients, in particular to optimize calories and protein intakes and to increase the early use of enteral nutrition.     

Introduction à l’analyse de la performance en réanimation

Performance assessment of ICU should be multidimensional and adapted to the specificity of each unit (type of hospital, missions). The media are fond of simple indicators enabling ranking of units or hospital. These indicators do not consider the specificity of each unit (case mix, constrains) and are integrated in a single composite score with an arbitrary weight for each item. Each unit should follow different indicators covering different aspects of performance. These indicators should be gathered in a “tableau de bord” and need to be discussed by the whole team and integrated in a quality improvement process. The performance indicators should be considered as tools used in order to improve the internal management, to ease the discussion with the administration and to improve the information delivered to “customers” of the ICU (patients, referring physicians).     

Mesure de la performance économique en réanimation

The aim of this work is to evaluate the economic efficiency of French intensive care units (ICUs). We develop a two-stage model. In the first step, we use an extended Data Envelopment Analysis model to evaluate the performance of ICUs at the patient level. Few applied works use patient data to gauge efficiency of health care organizations. From a methodological viewpoint, we introduce a directional distance function to gauge performance for each patient in terms of global ICU resources. From an empirical viewpoint, we introduce validated resource utilization indexes (medical and nursing dimensions) and we also control for case-mix heterogeneity with categorical variables including relevant individual measures of illness severity (SAPS II). Data come from a French survey including 15 178 patients of 26 ICUs in the region of Paris over the year 2000. Results show potential savings up to 30% of ICU’s resources and a strong concentration of inefficiency over 20% of patients.     

Évaluation de la composition corporelle en réanimation : avantages et limites

The risk of undernutrition is elevated in the intensive care unit (ICU). This risk will increase during the next decades because of ageing and higher prevalence of obesity, chronic diseases, and cancer, which are associated with a high risk of fat-free mass (FFM) loss. In these situations, the clinical and biological assessment of nutritional status is not accurate to estimate FFM loss. Energy deficit, leading to FFM loss, is correlated with the prognosis and clinical outcome during the ICU stay, and impairs patient’s muscle function and quality of life after ICU stay. Assessment of body composition should be implemented in the clinical practice in the setting of an early and optimized nutritional management. Because of its simplicity, reproducibility, and low cost, bioelectrical impedance (BIA) appears to be the method of choice to assess the body composition in the ICU. BIA also allows to calculate the phase angle, which is directly associated with prognosis. Given the importance of FFM loss during the ICU stay, body water variations less than ± 2 kg should not distort FFM loss identification. BIA could also be used as a method of measurement of body water variations. As recently suggested in oncology patients, body composition could be accurately evaluated by computed tomography images, which are frequently performed at the early phase of critical illness. Repeated FFM measurement could reduce undernutrition-related complications and costs as well as improve the quality of life of ICU patients.     

Intérêt de l’évaluation quantitative des sources d’inconforts en réanimation

Potential sources of discomfort or stressors associated with an intensive care unit (ICU) stay can be classified as intrinsic or patient-related factors, environmental factors (such as noise and excess of light), and organizational factors. Two approaches facilitate the assessment of ICU-related stressors: first an objective approach by measuring physical or physiological parameters that characterize either ICU-related stressors or their impact on the critically ill patient, and second, a subjective approach using questionnaires (patient-related outcomes). Pain is frequently reported by ICU patients as the main stressful condition, in relation to many therapeutic or diagnostic procedures. Thirst and sleep deprivation are also perceived very negatively by ICU patients in studies based on questionnaires investigating patient-related outcomes. ICU stays without control of stressors may induce agitation and confusion (ICU psychosis) and increase the risk of developing a post-traumatic stress disorder. Promoting the IPREA (Inconforts des Patients de REAnimation, discomfort in critically ill patients) questionnaire and its implementation in routine clinical practice could be the starting point for the development of quality assurance programs based on the Deming Approach—PDCA “Plan Do Check Act.”     

Désescalade de l’antibiothérapie en réanimation

Successful treatment of severe infections in the intensive care unit (ICU) often requires broad-spectrum empiric therapy, while attempting to control the source of infection. However, this liberal antibiotic strategy may be associated with adverse effects on the patients as well as on the overall microbial ecology of the unit. This “antibiotic dilemma” may be solved by early de-escalation of antibiotic therapy, which allows reducing the overall antibiotic exposure of ICU patients by shortening the duration of therapy (including early stop when infection is not confirmed), switching from combined to single therapy, and/or substituting broad-spectrum agent with narrower-spectrum regimen. The opportunity for de-escalation varies across series from 20% to 50%, depending on the empiric antibiotic policy and the epidemiological context. Adapting the antibiotic regimen, possible as early as 24 h after obtaining the first results from adequate samples, is mandatory at 48–72 h, once full microbiological results are obtained. Subsequently, the intensivist must reassess daily the continued need for antibiotics, just like sedation is reassessed daily in mechanically ventilated patients. Several studies have confirmed that early deescalation is safe, and recent evidence suggests that it may even be associated with improved outcome of patients.     

Intérêts et limites de la posturographie pour l’évaluation des troubles de l’équilibre

Posturography, i.e. the assessment of balance based on modifications to the pressure centre collected by a force platform, has seen many developments over the last forty years. Recently, improvements have been proposed in the area of experimental conditions (single-leg balancing, limits of stability, dynamic posturography) and also to signal analysis (non-linear analysis). Even if posturography is the most suitable means for assessing the upright position, its place in the evaluation of balance problems remains under discussion. There are many reasons why its use has not been widely accepted. Indeed, aside from the initial purchase cost and the collecting and interpretation of results, many authors have called into question the reproducibility of the tests, their sensitivity, their specificity and their interest with regard to other clinical or instrumental examinations for certain diseases. These are the elements that will be tackled here, with the understanding that developments are constantly being put forward in this area, that will see a regular increase in the number of publications on this subject.     

Effets stimulants respiratoires de l’acétazolamide en réanimation

Patients suffering from chronic obstructive pulmonary disease (COPD) present episodes of respiratory exacerbation, which may be severe and necessitate ventilatory support. Persistent failure to discontinue invasive mechanical ventilation is a major issue in patients suffering from COPD. Metabolic alkalosis is a common finding in the intensive care unit, associated with a worse outcome. In COPD patients, this condition is called post-hypercapnic alkalosis and represents a complication of mechanical ventilation. Reversal of metabolic alkalosis may facilitate weaning from mechanical ventilation of COPD patients. Acetazolamide, a non-specific carbonic anhydrase inhibitor, is one of the drugs used in the intensive care unit to reverse metabolic alkalosis. Acetazolamide is relatively safe. Its pharmacodynamics and compartmentalization of the different isoforms of carbonic anhydrase enzyme may in part explain the lack of evidence of acetazolamide’s efficacy as respiratory stimulant. Recent findings have suggested that acetazolamide doses routinely used in the intensive care unit may be insufficient to significantly improve respiratory parameters in mechanically ventilated COPD patients, especially in the presence of high serum chloride levels or co-administration of systemic corticosteroids or furosemide. Randomized controlled trials using adequate doses of acetazolamide are required to address this issue.     

Méningoencéphalites infectieuses de l’adulte non immunodéprimé en réanimation

Encephalitis refers to an acute or subacute, inflammatory process affecting the brain in association with clinical evidence of neurologic manifestations such as altered consciousness, seizures or focal disturbances and cerebrospinal fluid abnormalities. This clinical syndrome is associated with a number of infectious, post-infectious, and non-infectious causes. An infection by a virus is the most common and important cause of encephalitis, although bacteria and parasites may sometimes be responsible for this syndrome. Three recent multicentre studies conducted in the USA, France and England, respectively, have shown that extensive testing may substantially reduce the proportion of unknown causes, which still varies from 37 to 70%.Magnetic resonance imaging is the most sensitive neuroimaging test to evaluate patients with encephalitis, while performing nucleic acid amplification by polymerase chain reaction (PCR) of CSF specimens may increase the ability to identify certain etiologic agents. Herpes simplex virus is the most frequent cause of sporadic necrotizing encephalitis and is the most frequently identified pathogen. Since Herpesviral encephalitis is associated with a substantial incidence of mortality and severe disability, early acyclovir therapy should be initiated in all patients with suspected encephalitis, pending results of neuroimaging and PCR testing. The number of emerging infectious diseases (EIDs) and the magnitude of their threat to global health is increasing. Viral EID’s may produce severe neurologic symptoms including encephalitis. In patients with encephalitis and a history of recent illness, the diagnosis of acute disseminated encephalomyelitis should be considered.