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.

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.

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.

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.

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.

Predictive factors for rhabdomyolysis after bariatric surgery.

BACKGROUND: Prevalence of obesity is increasing internationally. Obesity is also incriminated in the development of postoperative rhabdomyolysis (RML). Its major risk is the development of renal failure which is associated with high mortality. The aim of this study was to determine the risk factors for RML in patients undergoing bariatric surgery. METHODS: Over a 12-month period, 49 consecutive patients were studied. They underwent gastric banding (n=32) or intestinal or gastric bypass (n=17) for morbid obesity (BMI >40 kg/m(2)). Surgery was performed in the supine position with a lumbar pad placed for intestinal shunt. The duration of surgery, persistent postoperative muscular pain, and pre- and postoperative creatine kinase (CK) were recorded. RML was defined as postoperative CK >1000 IU. L(-1) (5 times the normal value). Patients were retrospectively divided into 2 groups according to the presence or not of RML. In order to assess the role of BMI, it was decided to conduct an additional analysis in a group of consecutive non-obese patients who were matched for other risk characteristics. RESULTS: In the 49 patients included in the study 13 developed RML (26.5%). Surgery >4 hours, presence of diabetes and patient ASA physical status III or IV were identified as factors associated with higher risk of RML. In the matched group (9 patients), no one developed postoperative RML. CONCLUSIONS: After surgery for obesity, the risk of RML increases with prolonged surgery (>4 hours) and in diabetic obese patients with BMI >40 kg/m(2). In such patients, CK could be systematically measured to verify the presence of muscle injuries.

Cyclic adenosine 3',5'-monophosphate-dependent regulation of purified bovine aortic calcium/calmodulin-dependent myosin light chain kinase.

Myosin light chain kinase was extracted from bovine aortic muscularis by a low ionic strength buffer containing 50% glycerol. It was purified 130-fold with a 10% yield by anion-exchange chromatography followed by affinity chromatography on calmodulin-Sepharose. The enzyme was 95% calcium/calmodulin-dependent and exhibited a specific activity of 2-6 mumol/min per mg. It phosphorylated the myosin regulatory light chain exclusively. The apparent Kd for calmodulin was 6.3 nM. Upon phosphorylation of the enzyme by the catalytic subunit of cyclic AMP-dependent protein kinase, its affinity for calmodulin decreased 4-fold, without alteration of the V. When examined by SDS-polyacrylamide gel electrophoresis, the purified enzyme was made up of two major peptides (Mr 142 000 and 131 000, respectively), with a minor 80 000 dalton peptide. All these peptides were 32P-labeled after incubation with [gamma-32P]ATP and the catalytic subunit of cyclic AMP-dependent protein kinase. Also, after non-denaturing polyacrylamide gel electrophoresis, they all exhibited myosin light chain kinase activity, suggesting that the 131 000 and 80 000 dalton species are proteolytic products of the native enzyme of Mr 142 000. Vascular smooth muscle myosin light chain kinase is therefore soluble, calcium/calmodulin dependent and phosphorylatable by cyclic AMP-dependent protein kinase with concomitant decrease in its affinity for calmodulin. These features account for the beta-adrenergic relaxation of vascular smooth muscle.

Role of nitric oxide in restenosis after experimental balloon angioplasty in the hypercholesterolemic rabbit: effects on neointimal hyperplasia and vascular remodeling.

OBJECTIVES: The purpose of this study was to assess the effects of L-arginine and N(G)-nitro-L-arginine methyl ester (L-NAME) on neointimal hyperplasia and vascular remodeling after balloon angioplasty in the hypercholesterolemic rabbit. BACKGROUND: Restenosis after balloon angioplasty is a consequence of both neointimal hyperplasia and vessel remodeling. Nitric oxide inhibits neointimal hyperplasia, but its effect on vessel remodeling is unknown. METHODS: Six weeks after induction of bilateral iliac atherosclerosis, 48 rabbits underwent successful angioplasty in 75 vessels. Eight rabbits (acute group) were sacrificed immediately after angioplasty. The remaining animals received either placebo (chronic control group), or a diet supplemented with either L-arginine (1.5 g/kg/day), or L-NAME (15 mg/kg/day) for 4 weeks after angioplasty. RESULTS: The intimal area was significantly greater in the chronic control group compared to the acute group (2.60+/-1.03 mm2 vs. 1.35+/-0.62 mm2). This increase in intimal area was lower in the L-arginine group (1.79+/-0.61 mm2), and greater in the L-NAME group (3.23+/-0.92 mm2). The area circumscribed by the internal elastic lamina (IEL) increased significantly in the control group compared to the acute group (from 2.52+/-0.66 to 3.33+/-0.85 mm2); a more marked increase occurred in the L-NAME group (3.90+/-0.85 mm2). By contrast, IEL area was unchanged in the L-arginine group (2.41+/-0.62 mm2). As a result, there was no significant difference in lumen area after 4 weeks in the chronic groups (control: 0.74+/-0.38 mm2; L-arginine: 0.50+/-0.43 mm2; L-NAME: 0.48+/-0.42 mm2). CONCLUSIONS: Our results demonstrate that L-arginine inhibits whereas L-NAME stimulates neointimal hyperplasia after experimental balloon angioplasty in the hypercholesterolemic rabbit. However, the lack of vessel enlargement in the L-arginine group resulted in a similar final lumen size in the L-NAME and L-arginine groups.

[Interest of mannequin based simulator to evaluate anaesthesia residents]. / Intérêt du simulateur d'anesthésie pour l'évaluation des internes d'anesthésie-réanimation.

OBJECTIVE: The aim of this study was to test simulator validity to evaluate the ability of anaesthesia residents to solve two simulated scenarios. STUDY DESIGN: Monocentre, prospective, randomized study. POPULATION: Anaesthesia residents. METHODS: All anaesthesia residents were invited to participate into the study but were free to decline to take part. The authors developed grading forms to evaluate preoperative preparation of anaesthesia room and two simulated scenarios which had been previously validated. All residents were evaluated on the preoperative preparation of anaesthesia room. A randomization was performed to select half of the residents to be tested on one of the simulated scenario. Two experienced anaesthesiologists scored the residents' performance. At the end of the simulated session, residents rated the realism of the scenarios. RESULTS: Among 72 training residents in our institution, 48 participated with 24 beginning and 24 advanced residents. Median scores were similar between beginning (first and second year) and advanced residenced (third and fourth year) for the preoperative preparation of anaesthesia room (17 vs 17 for a maximal score of 25) while scores tended to be higher in advanced residents for simulated scenarios (scenario 1 [34 vs 19 for a maximal score of 55; p = 0.0009], scenario 2 [17 vs 13 for a maximal score of 45; p = 0.58]). However, numerous management errors were observed and some of them did not improve with training. Anaesthesia residents rated the simulator scenarios as realistic. CONCLUSION: This study suggests that mannequin-based simulator appears as a reliable and valid tool to test the performance of anaesthesia residents during critical situations.

[Perioperative evolution of the nutritional status in head and neck surgical patients. Prospective and descriptive case series]. / Evolution périopératoire du statut nutritionnel en chirurgie carcinologique des voies aérodigestives supérieures. Etude prospective et descriptive.

AIM OF THE STUDY: To assess the perioperative evolution of the nutritional status of head and neck surgical patients. DESIGN: Prospective, descriptive case series. PATIENTS AND METHODS: Fifty-four patients candidates for total or partial laryngectomy for malignancy of the neck tract without a past of neck surgery. The nutritional status of all patients hospitalized for total pharyngolaryngectomy, total or partial laryngectomy was assessed by 1) clinical parameters including weight (W), weight variation (WV, percentage of loss), Body Mass Index (BMI), triceps skin fold measurement (T), midarm circumference (M), and 2) biological parameters such as serum albumin (SA), transthyretin (TTR), lymphocytes (Ly). These parameters were noted at the time of diagnostic laryngoscopy (T1), the day before surgery (T2), and 10 days afterward (T3) when patients were authorized to eat normally. All patients had enteral nutrition (EN) support (35 kcal/kg/day) starting at D1 and for 10 days afterward. Only complete data per patient were analyzed. RESULTS: 24 patients were excluded. During the 21 days [7-53] preoperative period (T1-T2), WV was (6.6% [-8,1-+20.0] [T2] vs. 4.7% [-12,9-+20.0] [T1], p<0.05) without difference in T and M. In the postoperative period (T2-T3), all parameters worsened, except T, with: WV (8.2% [-8,1-+20.0] [T3], p<0.05 vs T2), M (27.4 cm [20.0-37.0] [T3] vs 28.3 cm [20.5-39.0] [T2], p<0.05) et TTR (0.21 mg/l [0.09-0.36] [T3] vs. 0.27 mg/l [0.08-0.45] [T2], p<0.05). BMI was 22.9 [15.2-36.7] (T1) vs 22.9 [15.2-35.3] (T2), NS and 22.1 [15.0-34.9] (T3), p<0.05 vs (T2). CONCLUSION: The nutritional status in malignancy head and neck surgical patients seems to be best assessed by loss weight. It worsened mainly during the postoperative period even if a well-conducted EN was performed as defined by the French consensus conference.

[Perioperative management of asplenic patients]. / Prévention du risque infectieux postopératoire chez les patients splénectomisés.

OBJECTIVE: In 2003, asplenia had involved 250000 patients in France. These patients are at risk of severe infection, mostly with capsulated bacteria as pneumococci, meningococci and Haemophilus. The higher mortality and morbidity due to infection in asplenic patient led in June 2003 a French expert committee to propose preventive management based on vaccination and antibioprophylaxis. STUDY DESIGN: Update article. DATA SYNTHESIS: For vaccination, two vaccines against pneumococci are available. The first one, the antipolysaccharide (Pneumo 23) is recommended for adults. It is effective for the majority of the serotypes even if its efficacy can be variable. The second one a conjugated pneumococcal vaccine (Prenevar) is used for children under two years because it has higher activity on antibiotic resistant strains therefore increasing antibiotic prophylaxis efficiency. When splenectomy is required, vaccination against pneumococci, Haemophilus (b type) and C meningococci must be performed at least 15 days before surgery, in order to get better immune stimulation. In case of emergency, vaccines have to be administrated within 30 days after surgery. Antibioprophylaxis is based on cefazolin injection before splenectomy and by postoperative intravenous amoxicillin administration. As soon as oral intake is allowed, antibioprophylaxis is continued for at least two years in adults and five years in children. Both antibiotic and vaccination have been reported to reduce pneumococcus infections.

Myofilament calcium sensitivity is decreased in skinned cardiac fibres of endotoxin-treated rabbits.

OBJECTIVE: The aim was to determine whether myofilament Ca2+ sensitivity is altered in skinned cardiac fibres from endotoxin-treated rabbits. METHODS: Endotoxin was injected i.v. in conscious New-Zealand White rabbits at a dose of 0.5 mg/kg (groups I, II, and III) or 1 mg/kg (group IV). A fifth group was used as control. Hearts were excised 4 h (groups I and IV), 24 h (group II), or 5 days (Group III) after injection. Skinned fibres were obtained with chemical (EGTA + Brij 58) treatment of bundles isolated from papillary muscles. RESULTS: The maximal Ca(2+)-activated force (F0) of skinned cardiac fibres was not different between groups. However, [Ca2+] required to evoke 50% of F0 (Ca50) was higher in the fibres from group I than in controls (1.78 +/- 0.05 vs. 1.53 +/- 0.03 microM; P < 0.05). This effect was dose-dependent (group IV: Ca50 = 2.08 +/- 0.12 microM; P < 0.05 vs. group I), larger after 24 h (group II: Ca50 = 2.12 +/- 0.05 microM; P < 0.05 vs. group I). By 5 days, myofilament Ca2+ sensitivity had returned to normal (group III: Ca50 = 1.54 +/- 0.05 microM). CONCLUSION: Myofilament Ca2+ sensitivity is decreased in skinned fibres taken from rabbit myocardium after i.v. endotoxin injection. This effect is dose- and time-dependent, and reversible with time.

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.

Calcium-calmodulin-dependent phosphorylations in the control of muscular contraction?

Muscular contraction is triggered by the increase in free calcium concentration and modulated by cyclic nucleotide-dependent phosphorylation. Beside a direct trigger of sarcomeric muscle contraction through binding of troponin C, calcium ions trigger or modulate contractility through calcium-calmodulin-dependent myosin light chain kinases, and increase the rate of relaxation through the calmodulin-dependent phosphorylation of phospholamban, the activator of the cardiac sarcoplasmic reticulum calcium pump. In both cases, a concerted regulation by calcium and cyclic nucleotides is observed. Hyperactivation of the calcium pump is brought about by additional phosphorylation of phospholamban by cAMP-dependent protein kinase. Similarly myofibrillar myosin light chain kinases from smooth and skeletal muscles are substrates of the cAMP-dependent protein kinase. The calmodulin-dependent protein kinases are probably organized into supramolecular regulatory complexes.

Impaired contractile response of mesenteric arteries in Crohn's disease.

BACKGROUND: Crohn's disease is associated with vascular injury and dysregulation of the intestinal immune system which together can provide disturbance of mesenteric circulation functional properties. AIM: To evaluate the vascular reactivity of mesenteric arteries from patients with Crohn's disease. METHODS: Phenylephrine-induced contractions were assessed from 10 patients with Crohn's disease and 8 control organ donors. NG-nitro-L-arginine-methyl-ester (L-NAME) was used to test the presence of inducible NO synthase. Endothelium dependent and independent relaxation was assessed using acetylcholine, bradykinin, calcium ionophore A23187 and sodium nitroprusside. RESULTS: The contractile response to phenylephrine was significantly decreased in arteries without endothelium from patients with Crohn's disease. Exposure to the NO synthase inhibitor L-NAME restored the contractile response to phenylephrine. Relaxation remained unaltered in both groups. CONCLUSION: These data provide direct evidence for fading of contraction caused by phenylephrine in Crohn's disease. The restored mesenteric artery tone by a specific NO synthase inhibitor suggests that an increased production for NO in vascular smooth muscle might be responsible of this altered vascular reactivity.

Effects of nitric oxide synthase inhibition on regional hemodynamics and oxygen transport in endotoxic dogs.

Nitric oxide synthase (NOS) inhibition has been used to increase blood pressure in humans with septic shock despite a lack of data regarding its effects on O2 delivery (QO2). We studied the effects of NG-nitro-L-arginine methyl ester (L-NAME) on systemic, gut, and hindlimb circulations of endotoxic dogs. Twelve dogs were infused with 2 mg/kg of LPS over 1 h followed by 60 mL/kg of 6% dextran over 2 h. Six dogs also received 20 mg/kg of L-NAME, LPS caused mean arterial pressure (MAP), flow and QO2 to whole body, hindlimb and gut to decrease, but O2 uptake (VO2) did not change. Dextran resuscitation alone produced a hyperdynamic state with increased blood flow to or above baseline. With L-NAME, systemic and regional resistances increased twofold and MAP returned to near baseline. Late in the study, these dogs had significantly lower blood flow and QO2 to the gut but maintained VO2 by increasing oxygen extraction to near critical levels. These data suggest that in acute endotoxicosis, L-NAME may significantly improve blood pressure but may markedly encroach on O2 transport reserves to the gut.

EPISEPSIS: a reappraisal of the epidemiology and outcome of severe sepsis in French intensive care units.

OBJECTIVE: Ten years ago 8.4% of patients in French intensive care units (ICUs) were found to have severe sepsis or shock and 56% died in the hospital. As novel therapies for severe sepsis are emerging, updated epidemiological information is required. DESIGN AND SETTING: An inception cohort study conducted in 206 ICUs of randomly selected hospitals over a 2-week period in 2001, including all patients meeting criteria for clinically or microbiologically documented severe sepsis (with > or =1 organ dysfunction). MEASUREMENTS AND RESULTS: Among 3738 admissions, 546 (14.6%) patients experienced severe sepsis or shock, of which 30% were ICU-acquired. The median age of patients was 65 years, and 54.1% had at least one chronic organ system dysfunction. The median (range) Simplified Acute Physiology Score (SAPS II) and Sequential Organ Failure Assessment (SOFA) at onset of severe sepsis were 48 (2-129) and 9 (1-24), respectively. Mortality was 35% at 30 days; at 2 months the mortality rate was 41.9%, and 11.4% of patients remained hospitalized. The median (range) hospital stay was 25 (0-112) days in survivors and 7 (0-90) days in non-survivors. Chronic liver and heart failure, acute renal failure and shock, SAPS II at onset of severe sepsis and 24-h total SOFA scores were the independent risk factors most strongly associated with death. CONCLUSIONS: Although the attack rate of severe sepsis in French ICUs appears to have increased over the past decade, its associated mortality has decreased, suggesting improved management of patients. Severe sepsis incurs considerable resources use, and implementation of effective management strategies and continued research efforts are needed.

Myasthenia gravis and steroid-induced myopathy of the respiratory muscles.

OBJECTIVE: We report a case of corticosteroid-induced myopathy with involvement of respiratory muscles observed in a myasthenic patient. PATIENT: A 37-years-old woman, under corticosteroid treatment for two years for typical myasthenia gravis was admitted to ICU for acute myasthenic respiratory failure. Weaning from mechanical ventilation remained impossible despite 4 plasma exchanges and azathioprine. The patient exhibited a progressive 12 kg weight loss with muscular weakness and atrophy. MEASUREMENTS AND RESULTS: Peripheral and diaphragmatic electromyography as well as histological study were consistent with a steroid-induced myopathy. Discontinuation of corticosteroid treatment was followed by a rapid weight gain with general improvement and allowed weaning from mechanical ventilation with a complete recovery. CONCLUSION: This case provides evidence that corticosteroid-induced myopathy may be observed in myasthenia gravis and may involve the respiratory muscles as well as the peripheral musculature.