Difference in venous-arterial carbon dioxide in septic shock.

Determining the venous-to-arterial PCO2 difference (PCO2gap) during resuscitation of septic shock patients might be useful when deciding when to continue resuscitation despite a ScvO2>70% associated with hyperlacticemia. Because hyperlacticemia is not a discriminatory factor in defining the cause of that stress, a PCO2gap>6 mmHg could be used to identify global tissue hypoperfusion. Monitoring the "Gap" could be a useful complementary tool after optimization of O2-derived parameters was achieved to evaluate the adequacy of blood flow to global metabolic demand. In this regard it can help to titrate inotropes in order to adapt O2 delivery to CO2 production, or to choose between haemoglobin correction or fluid/inotrope infusion in patients with a too low ScvO2 related to metabolic demand.

Do established prognostic factors explain the different mortality rates in ICU septic patients around the world?

BACKGROUND: The aim of this paper was to clarify if previously established prognostic factors explain the different mortality rates observed in ICU septic patients around the world. METHODS: This is a sub-study from the PROGRESS study, which was an international, prospective, observational registry of ICU patients with severe sepsis. For this study we included 10930 patients from 24 countries that enrolled more than 100 patients in the PROGRESS. The effect of potential prognostic factors on in-hospital mortality was examined using univariate and multivariate logistic regression. The complete set of data was available for 7022 patients, who were considered in the multivariate analysis. Countries were classified according to country income, development status, and in-hospital mortality terciles. The relationship between countries' characteristics and in-hospital mortality was evaluated using linear regression. RESULTS: Mean in-hospital mortality was 49.2%. Severe sepsis in-hospital mortality varied widely in different countries, ranging from 30.6% in New Zealand to 80.4% in Algeria. Classification as developed or developing country was not associated with in-hospital mortality (P=0.16), nor were levels of gross national product per capita (P=0.15). Patients in the group of countries with higher in-hospital mortality had a crude OR for in-hospital death of 2.8 (95% CI 2.5-3.1) in comparison to those in the lower risk group. After adjustments were made for all other independent variables, the OR changed to 2.9 (95% CI 2.5-3.3). CONCLUSION: Severe sepsis mortality varies widely in different countries. All known markers of disease severity and prognosis do not fully explain the international differences in mortality. Country income does not explain this disparity either. Further studies should be developed to verify if other organizational or structural factors account for disparities in patient care and outcomes.

Modelling pathogen fate in stormwaters by a particle-pathogen interaction model using population balances.

Stormwater is polluted by various contaminants affecting the quality of receiving water bodies. Pathogens are one of these contaminants, which have a critical effect on water use in rivers. Increasing the retention time of water in stormwater basins can lead to reduced loads of pathogens released to the rivers. In this paper a model describing the behaviour of pathogens in stormwater basins is presented including different fate processes such as decay, adsorption/desorption, settling and solar disinfection. By considering the settling velocity distribution of particles and a layered approach, this model is able to create a light intensity, and particle and pathogen concentration profile along the water depth in the basin. A strong effect of solar disinfection is discerned. The model has been used to evaluate pathogen removal efficiencies in stormwater basins. It includes a population of particle classes characterized by a distribution of settling velocities in order to be able to reproduce stormwater quality and treatment in a realistic way.

Impact of a prophylactic strategy on the incidence of nausea and vomiting after general surgery.

BACKGROUND: This study aimed to evaluate the implementation of a strategy to prevent postoperative nausea and vomiting (PONV) in patients undergoing general surgery. STUDY DESIGN: Prospective observational study. METHODS: A first period was observational. During a second period, a strategy to prevent PONV was based on five risk factors (RF) identified after the first phase. From two RF, antiemetic treatment was given according to the number of RF. The incidence of PONV was recorded in postoperative anaesthesic care unit (PACU) and at the 24th postoperative hour (24h). RESULTS: We prospectively enrolled 823 patients. Implementation of a prophylactic PONV strategy was associated with a decrease of nausea in PACU from 29.9 to 9.8% (P<0.001) and at 24h from 19 to 10.3% (P<0.001). Vomiting decreased from 12.4 to 2.3% (P<0.001) in PACU and from 5.6 to 3.7% at 24h (non-significant). CONCLUSION: Prophylaxis of PONV by the administration of antiemetic treatment according to a strategy based on a local risk score was efficient and associated with a significant decrease of PONV.

[Anaesthetic management for caesarean delivery and acute myocardial infarction by spontaneous coronary dissection]. / Anesthésie pour césarienne à la phase aiguë d'un infarctus du myocarde par dissection coronaire.

Myocardial infarction is rare during pregnancy and is associated with a high maternal and foetal mortality rate. We report the case of a 32-year-old woman at 38 weeks gestation who developed a myocardial infarction with spontaneous coronary dissection treated with coronary angioplasty and who needed an emergency caesarean section. We discuss the anaesthetic management of urgent caesarean section in this context.

[Measure of preoperative anxiety and need for information with six issues]. / Mesure de l'anxiété et du besoin d'informations préopératoire en six questions.

INTRODUCTION: A questionnaire for self-assessment, the Amsterdam Preoperative Anxiety and Information Scale (APAIS) translated into French has been compared to a background questionnaire to validate their use as screening tool and assessment of anxiety and information needs of patients. PATIENTS AND METHOD: An epidemiological study was conducted anonymously. Patients completed a questionnaire comprising a French version of APAIS and Spielberger Anxiety Inventory (STAI). A study of correlation between scores for each questionnaire was conducted. A high level of anxiety was investigated. RESULTS: So 1800 questionnaires were distributed, 1504 were usable. The first 100 questionnaires have confirmed the internal validity of the questionnaire APAIS. The following questionnaires in 1404 accounted 49.7% of men 55.7 ± 15.7 years old and 50.2% of women 50.8 ± 15.2 years old. The correlation coefficient (r) between STAI state and appeasement was of 0.675 (P<0.001). A score higher than 10/20 by APAIS corresponded to 73% of patients with high anxiety by Spielberger's inventory. No correlation was found between the STAI state and the need for information (r=0.252; P<0.001). CONCLUSION: APAIS, in its French version, assesses anxiety and information needs of patients. This questionnaire has metrological capabilities and ease of execution that make it a screening tool for use in anesthesia consultation. A score above 10 out of 20 reflects a high level of anxiety.

[Hydroxyethyl starch]. / Les hydroxyéthylamidons.

OBJECTIVE: The purpose of this review is to draw up a statement on current knowledge available on the more recent hydroxyethyl starch (HES). DATA SOURCES: References were obtained from computerized bibliographic research (Medline), recent review articles, the library of the service and personal files. STUDY SELECTION: All categories of articles on this topic have been selected. DATA EXTRACTION: Articles have been analysed for biophysics, pharmacology, toxicity, side effects, clinical effects and using prospect of HES. DATA SYNTHESIS: The first HES was made available in the United States in 1970. The development of a new generation of HES restarted the discussion on clinical interest and the limits in the use of these macromolecules. This interest is also strengthened today by the recent data attached to plasma substitution in intensive care or perioperative resuscitation. The interest for crystalloids and colloids is still widely debated, and among the latter, the relative interest of the HES last generation compared to older ones. Recent HES development is in line with a decrease molecular weight, change rate molar substitution and to amend the glucose to hydroxyethyl report. The ultimate goal is to reduce the side effects of these molecules preventing their use. Side effects are dominated by haemostasis and renal dysfunction. The latest developments are the so-called HES "balanced" solutions.

[Benefits and indications of xenon anaesthesia]. / Avantages décisifs, indications et limites de l'anesthésie au xénon.

OBJECTIVE: To analyze the current knowledge related to xenon anaesthesia. DATA SOURCES: References were obtained from computerized bibliographic research (Medline), recent review articles, the library of the service and personal files. STUDY SELECTION: All categories of articles on this topic have been selected. DATA EXTRACTION: Articles have been analyzed for biophysics, pharmacology, toxicity and environmental effects, clinical effects and using prospect. DATA SYNTHESIS: The noble gas xenon has anaesthetic properties that have been recognized 50 years ago. Xenon is receiving renewed interest because it has many characteristics of an ideal anaesthetic. In addition to its lack of effects on cardiovascular system, xenon has a low solubility enabling faster induction of and emergence from anaesthesia than with other inhalational agents. Nevertheless, at present, the cost and rarity of xenon limits widespread use in clinical practice. The development of closed rebreathing system that allowed recycling of xenon and therefore reducing its waste has led to a recent interest in this gas. CONCLUSION: Reducing its cost will help xenon to find its place among anaesthetic agents and extend its use to severe patients with specific pathologies.

Sevoflurane pre- and post-conditioning protect the brain via the mitochondrial K ATP channel.

BACKGROUND: This study aimed to evaluate whether exposure to sevoflurane at the onset of reperfusion provides protection similar to sevoflurane preconditioning and whether the effect depends on mitochondrial potassium ATP-dependent channel (mitoK(ATP)) in a rat model of focal cerebral ischaemia. METHODS: Adult Wistar male rats were subjected to focal cerebral ischaemia for 1 h followed by 24 h or 7 days of reperfusion. Preconditioning consisted of 15 min exposure to sevoflurane at 1 minimum alveolar concentration (2.6%) 72 h before ischaemia. Post-conditioning was performed by exposure to sevoflurane immediately at the onset of reperfusion or by a delayed exposure 5 min after the onset of reperfusion. The role of the mitoK(ATP) channel was assessed by i.p. injection of the selective blocker 5-hydroxydecanoate before each sevoflurane administration or by the mitoK(ATP) channel opener, diazoxide (DZX), given in place of sevoflurane. Cerebral infarct size, neurological deficit score, and motor coordination were evaluated 24 h and 7 days after reperfusion. RESULTS: Sevoflurane preconditioning and early post-conditioning reduced both cerebral infarct size and neurological defect score at 24 h of reperfusion whereas the sole sevoflurane post-conditioning improved motor coordination. At 7 days, only infarct volume remained lower in pre- and post-conditioned animals. Neuroprotection mediated by sevoflurane was lost when it was given 5 min after the onset of reperfusion and was abolished by inhibition of mitoK(ATP). DZX alone mimicked sevoflurane-induced pre- and post-conditioning. CONCLUSIONS: The pretreatment with sevoflurane or its early administration at reperfusion provides neuroprotection via mitoK(ATP) in a rat model of focal cerebral ischaemia.

Automated pulse pressure and stroke volume variations from radial artery: evaluation during major abdominal surgery.

BACKGROUND: Off-line calculation of the pulse pressure variation (PPV(ref)) has repeatedly been shown to be a reliable predictor of fluid responsiveness in mechanically ventilated patients. This study was designed to assess the ability of two algorithms for automated calculation of PPV (PPV(auto)) (Intellivue MP 70) and stroke volume variation (SVV(auto)) (FloTrac/Vigileo) to predict fluid responsiveness during abdominal surgery. METHODS: We conducted a prospective study of 56 fluid challenges given for haemodynamic instability in 11 patients undergoing major abdominal surgery. Fluid responsiveness was defined as an increase in stroke volume index (SVI) >10%. PPV(ref), PPV(auto), SVV(auto), and SVI (oesophageal Doppler) were recorded simultaneously before and after each fluid challenge. RESULTS: PPV(auto) and SVV(auto) both correlated with PPV(ref) [r(corr)=0.87 (P<0.0001) and 0.84 (P<0.0001), respectively; n=77]. All three indices measured before fluid challenges were higher in responder (n=32) than in non-responder (n=24) fluid challenges (P < or = 0.02). The mean areas under the receiver operating characteristic curves were 0.96 (PPV(ref)), 0.96 (PPV(auto)), and 0.95 (SVV(auto)), and the optimal threshold value for each variable was 13%, 13%, and 12%, respectively. All indices correlated with the fluid challenge-induced changes in SVI (PPV(ref): r(corr)=0.65; PPV(auto): r(corr)=0.58; SVV(auto): r(corr)=0.58, P<0.001 for all). CONCLUSIONS: PPV(auto) and SVV(auto) predict fluid responsiveness as accurately as off-line PPV(ref) in patients with haemodynamic instability during major abdominal surgery.

Promoting Global Research Excellence in Severe Sepsis (PROGRESS): lessons from an international sepsis registry.

BACKGROUND: The PROGRESS Registry (Promoting Global Research Excellence in Severe Sepsis) was designed to provide comparative data reflecting everyday clinical practice, thereby allowing participating institutions to explore and benchmark medical interventions in severe sepsis. MATERIALS AND METHODS: PROGRESS was an international, noninterventional, prospective, observational registry collecting data that describe the management and outcomes of severe sepsis patients in intensive care units (ICUs). Patients were enrolled who had been diagnosed with severe sepsis (suspected or proven infection and >or= 1 acute sepsis-induced organ dysfunction) at the participating institutions, where de-identified data were entered directly into a secured website. PROGRESS was governed by an independent international medical advisory board. RESULTS: PROGRESS took place in 276 ICUs in 37 countries, and 12,881 patients were identified as having severe sepsis. There was considerable variation among countries in enrollment levels, provision of standard treatment and supportive therapies, and ICU and hospital outcomes. Eight countries accounted for 65.2% of the enrolled patients. Males (59.3%) and Caucasian (48.6%) patients predominated the patient cohort. Diagnosis of severe sepsis was prior to ICU admission in 45.7% of patients, at ICU admission in 29.1% of patients, and after ICU admission in the remainder. Globally, ICU and hospital mortality rates were 39.2% and 49.6%, respectively. The mean length of ICU and hospital stay was 14.6 days and 28.2 days, respectively. CONCLUSIONS: The PROGRESS international sepsis registry demonstrates that a large web-based sepsis registry is feasible. Wide variations in outcomes and use of sepsis therapies were observed between countries. These results also suggest that additional opportunities exist across countries to improve severe sepsis outcomes.

[Contribution of central venous oxygen saturation in postoperative blood transfusion decision]. / Apport de la saturation veineuse centrale en oxygène dans la décision transfusionnelle postopératoire.

OBJECTIVE: The aim of this study was to assess the value of central venous oxygen saturation (ScvO(2)) for the decision of blood transfusion in comparison with the criteria of the French guidelines for blood transfusion (2003). STUDY DESIGN: Prospective, observational. PATIENTS AND METHODS: Sixty patients, haemodynamically stable, for whom a blood transfusion (BT) was discussed in the postoperative course of general surgery, were included. ScvO(2) (%) and haemoglobin (g/dl) were measured before and after BT. Patients were retrospectively divided into two groups according to ScvO(2) measured before BT (< or >or=70%). Results are expressed as median. RESULTS: The ScvO(2) before transfusion was greater or equal to 70% in 25 (47.2%) patients. Following BT, the ScvO(2) increased significantly (from 57.8 to 68.5%) in the group with initial ScvO(2) less than 70% whereas it was unchanged in patients with initial ScvO(2) greater or equal 70% (from 76.8 to 76.5%). Twenty patients (37.7%) did not meet the French guidelines for BT criteria. Eighteen patients out of 33 that met the criteria had ScvO(2) greater or equal 70% before BT while 13 patients with ScvO(2) less than 70% were not detected by these same criteria. CONCLUSION: ScvO(2) could be a relevant biological parameter to complete the current guidelines for BT in stable patient with a central venous catheter during the postoperative period.

Inhibition of biological phosphorus removal in a sequencing moving bed biofilm reactor in seawater.

A new process was developed to achieve denitrifying biological phosphorus removal in wastewaters containing high levels of nitrate and phosphate with a low level of organic matter. This could particularly be useful in recirculating systems such as aquariums or fish farms to prevent accumulation of nitrate and phosphates and to avoid regular cost extensive and polluting water replacement. Phosphorus (P) was removed from the influent in a sequencing moving bed biofilm reactor, stored in the attached biomass and then cyclically removed from the biomass by filling the reactor with anaerobic water from a stock tank. Phosphate was accumulated in the stock tank which allowed for use as fertilizer. The feasibility of the experimental design was demonstrated by using the activated sludge model No. 3 (ASM3) complemented by the EAWAG Bio-P module implemented in the WEST simulation software. A pilot scale experiment was conducted in two identical reactors in two runs: one to treat water from a marine mesocosm, the other to treat a synthetic freshwater influent. No biological phosphorus removal was achieved during the seawater run. During the freshwater run, average P removal efficiency was 20%, of which 80% was attributed to biological removal and 20% to chemical precipitation. The absence of efficiency in seawater was attributed to the high concentration of calcium.

Inflammation affects sufentanil consumption in ulcerative colitis.

BACKGROUND: Previous studies have demonstrated an increased perioperative opioid requirement during inflammatory disease. To evaluate the influence of the inflammatory process, we studied in the same patient the sufentanil requirement during procedures that occur during two distinct phases of ulcerative colitis with different inflammatory profiles: (1) left colectomy for major colitis unresponsive to medical treatment during acute inflammation and (2) coloprotectomy with ileoanal anastomosis, three months after recovery of the acute inflammatory episode. METHODS: Sixteen patients with clinical and histological evidence of ulcerative colitis scheduled for colectomy with ileoanal anastomosis were included. For each surgical procedure, anaesthesia was induced with sufentanil 0.5 microg kg(-1) and propofol 2 mg kg(-1). Patients were ventilated with 50% nitrous oxide and oxygen, and tidal volume was adjusted to keep end-tidal CO2 at 30 mmHg. Anaesthesia was maintained with end-tidal isoflurane at 0.5%. Analgesia was achieved with continuous infusion of sufentanil at 0.3 microg kg(-1) h(-1). Additional boluses of sufentanil and increases in infusion rates were used when haemodynamic variables increased to more than 20% of preoperative values. Sufentanil consumption during surgery was analysed by Wilcoxon signed rank sum test. P < 0.05 was considered significant. RESULTS: Total intra-operative sufentanil requirement was significantly larger during colectomy performed for acute inflammatory colitis than during ileoanal anastomosis performed after the inflammatory process (1.24 +/- 0.48 microg kg(-1) h(-1) vs. 0.62 +/- 0.3 microg kg(-1) h(-1); P < 0.05). CONCLUSION: For the same patient, inflammatory status influences opioid requirements during surgery for ulcerative colitis.