Modifiable Risk Factors for Delirium in Critically Ill Trauma Patients: A Multicenter Prospective Study.

OBJECTIVE:: Intensive care unit (ICU)-acquired delirium has been associated with increased morbidity and mortality. Prevention strategies including modification of delirium risk factors are emphasized by practice guidelines. No study has specifically evaluated modifiable delirium risk factors in trauma ICU patients. Our goal was to evaluate modifiable risk factors for delirium among trauma patients admitted to the ICU. DESIGN:: Prospective observational study. SETTING:: Two level 1 trauma ICU centers. PATIENTS:: Patients 18 years of age or older admitted for trauma including mild to moderate traumatic brain injury were eligible for the study. INTERVENTIONS AND MEASUREMENTS:: Delirium was assessed daily using the confusion assessment method for the ICU (CAM-ICU). The effect of modifiable risk factors was assessed using multivariate Cox regression analysis adjusting for severity of illness and significant nonmodifiable risk factors. MAIN RESULTS:: A total of 58 of 150 recruited patients (38.7%; 95% confidence interval [CI] 30.9-46.5) screened positive for delirium during ICU stay. When adjusting for significant nonmodifiable risk factors, physical restraints (hazard ratio [HR]: 2.13; 95% CI: 1.07-4.24) and active infection or sepsis (HR: 2.12; 95% CI: 1.18-3.81) significantly increased the risk of delirium, whereas opioids (HR: 0.35; 95% CI: 0.13-0.98), episodes of hypoxia (HR: 0.55; 95% CI: 0.31-0.95), access to a television/radio in the room (HR: 0.26; 95% CI: 0.11-0.62), and number of hours mobilized per day (HR: 0.77; 95% CI: 0.68-0.88) were associated with significantly less risk of delirium. CONCLUSION:: We have identified modifiable risk factors for delirium. Future studies should aim at implementing strategies to modify these risk factors and evaluate their impact on the risk of delirium.

Meningitis in adult patients with a negative direct cerebrospinal fluid examination: value of cytochemical markers for differential diagnosis.

INTRODUCTION: The objective of this study was to determine the ability of various parameters commonly used for the diagnosis of acute meningitis to differentiate between bacterial and viral meningitis, in adult patients with a negative direct cerebrospinal fluid (CSF) examination. METHODS: This was a prospective study, started in 1997, including all patients admitted to the emergency unit with acute meningitis and a negative direct CSF examination. Serum and CSF samples were taken immediately on admission. The patients were divided into two groups according to the type of meningitis: bacterial (BM; group I) or viral (VM; group II). The CSF parameters investigated were cytology, protein, glucose, and lactate; the serum parameters evaluated were C-reactive protein and procalcitonin. CSF/serum glucose and lactate ratios were also assessed. RESULTS: Of the 254 patients with meningitis with a negative direct CSF examination, 35 had BM and 181, VM. The most highly discriminative parameters for the differential diagnosis of BM proved to be CSF lactate, with a sensitivity of 94%, a specificity of 92%, a negative predictive value of 99%, a positive predictive value of 82% at a diagnostic cut-off level of 3.8 mmol/L (area under the curve (AUC), 0.96; 95% confidence interval (CI), 0.95 to 1), and serum procalcitonin, with a sensitivity of 95%, a specificity of 100%, a negative predictive value of 100%, and a positive predictive value of 97% at a diagnostic cut-off level of 0.28 ng/ml (AUC, 0.99; 95% CI, 0.99 to 1). CONCLUSIONS: Serum procalcitonin and CSF lactate concentrations appear to be the most highly discriminative parameters for the differential diagnosis of BM and VM.

Isolation of hydrocarbon-degrading extremely halophilic archaea from an uncontaminated hypersaline pond (Camargue, France).

Little information exists about the ability of halophilic archaea present in hypersaline environments to degrade hydrocarbons. In order to identify the potential actors of hydrocarbon degradation in these environments, enrichment cultures were prepared using samples collected from a shallow crystallizer pond with no known contamination history in Camargue, France, with n-alkanes provided as source of carbon and energy. Five alkane-degrading halophilic archaeal strains were isolated: one (strain MSNC 2) was closely related to Haloarcula and three (strains MSNC 4, MSNC 14, and MSNC 16) to Haloferax. Biodegradation assays showed that depending on the strain, 32 to 95% (0.5 g/l) of heptadecane was degraded after 30 days of incubation at 40 degrees C in 225 g/l NaCl artificial medium. One of the strains (MSNC 14) was also able to degrade phenanthrene. This work clearly shows for the first time the potential role of halophilic archaea belonging to the genera Haloarcula and Haloferax in the degradation of hydrocarbons in both pristine and hydrocarbon-contaminated hypersaline environments.

Can emergency physicians identify a high mortality subgroup of patients with sepsis: role of procalcitonin.

OBJECTIVE: To assess the potential role of procalcitonin and tumor necrosis factor-alpha, interleukin-6 and interleukin-8, in the prognosis of patients with sepsis. DESIGN: Prospective study. SETTING: The emergency unit of a teaching hospital. PATIENTS: We included 131 patients with sepsis: 15 (12%) with septic shock, 20 (15%) with severe sepsis and 96 (73%) with sepsis. MEASUREMENTS AND MAIN RESULTS: Out of the 131 patients, 112 (85.5%) survived and 19 (14.5%) died. These two groups of patients differed with regard to simplified acute physiology score II, severity of infectious disease and underlying disease, bacteremia and type of microorganisms. The mean serum levels of tumor necrosis factor, interleukin-6, interleukin-8, procalcitonin and lactates at study entry were higher in nonsurvivors than in survivors. Multivariate regression analysis showed the most significant of these variables to be serum procalcitonin level (P=0.0007), simplified acute physiology score II (P=0.03) and serum lactate level (P=0.03). Using a model incorporating these three variables, with a cut-off value corresponding to a 15% probability of predicting mortality, death could be correctly predicted in 99.5% of cases and survival in 95%. This cut-off value allowed us to maximize the prediction of death. When serum procalcitonin levels were not taken into account, the best model included simplified acute physiology score II and serum lactate and interleukin-6 levels, but the rate of correct prediction of death then dropped to 84%. CONCLUSIONS: Stepwise multivariate logistic regression analysis showed serum procalcitonin level to be a valuable marker of sepsis severity, compared with the 15 other clinical, biochemical and bacteriologic variables tested.

Analgesic efficacy of orodispersible paracetamol in patients admitted to the emergency department with an osteoarticular injury.

INTRODUCTION: Acute pain still persists in patients under treatment after admission to emergency departments (ED). The objective of this study was to determine the efficacy of 1 g of paracetamol in patients presenting an osteoarticular injury. MATERIALS AND METHODS: This prospective study included all patients admitted to the ED with an osteoarticular injury and a pain score above 30 on the visual analogue scale (VAS). Patients were selected on admission by the reception nurse and given paracetamol within 5 min of admission. VAS scores were recorded 30 and 60 min after admission. On discharge from the ED, the patients underwent a further VAS assessment and were asked a question about pain relief (yes/no answer). The primary endpoint was the VAS score at 60 min. The secondary endpoint was the pain relief expressed by the patient on discharge from the ED. RESULTS: Five hundred and seventy-one patients were included. The median stay in the ED was 90 min (75-120 min). The diagnoses at discharge were sprain or dislocation (ankle, knee, and wrist) for 287 patients, fracture for 102 patients, and other injury for 182 patients. In 69% of the patients, the injured limb was immobilized. The median VAS score on admission was 57. A significant difference was seen between the median VAS on admission and at 1 h after admission (57+/-18 vs. 30+/-18; P<0.0001), and between the median VAS score at admission and the score at discharge from the ED (57+/-18 vs. 26+/-18, P<0.0001). Finally, 81% of the patients expressed pain relief. On discharge from the ED, a gain of 20 mm on the VAS had a positive predictive value of 93% [area under curve (AUC): 89; CI: 86-92; P=0.001], for the endpoint 'patients stating pain relief'. CONCLUSION: A simple and easily applicable protocol of pain management permits the achievement of satisfactory analgesia during a patient's stay in the ED.

Risk factors associated with methicillin-resistant Staphylococcus aureus infection in patients admitted to the ED.

OBJECTIVES: The objective of our study was to define the characteristics of patients admitted to the emergency department (ED) presenting with a methicillin-resistant Staphylococcus aureus (MRSA) infection. PATIENTS AND METHODS: The study included all patients admitted to the ED between January 2003 and December 2004 in whom a staphylococcal infection was documented. The risk factors associated with carriage of MRSA, the diagnosis made in the ED, and the treatment administered were established from the patients' medical files. The sites from which the bacteria were isolated, the spectrum of resistance of the staphylococci to different antibiotics, and the presence or absence of the gene coding for Panton-Valentin leukocidin for certain S aureus isolates were determined from the reports issued by the bacteriologic department. Two groups of patients were compared: those with an infection caused by MRSA and those with an infection due to methicillin-susceptible S aureus (MSSA). RESULTS: A total of 238 patients were included, 93 presenting with an infection caused by MRSA and 145 an infection due to MSSA. The patients harboring MRSA had a higher median age than those carrying MSSA (74 vs 61 years, P = .0001), experienced a greater loss of autonomy (according to the Knauss index), and had more comorbidity factors. Nine patients, younger than 40 years, presented with an infection due to MRSA in the absence of any comorbidity factor or any factor associated with carriage of these bacteria. Seven patients in the MRSA group were tested for Panton-Valentine leukocidin genes, and a positive result was obtained in 2 of them. Regardless of whether the infection was caused by MRSA or by MSSA, the bacteria were most frequently isolated from a cutaneous site, in 40% and 65% of the patients, respectively. Irrespective of the group, 28% of the patients presented with bacteremia. The spectrum of resistance of these MRSA strains suggested a hospital rather than community origin. The initial antibiotic therapy was rarely appropriate in the case of an infection due to MRSA. CONCLUSION: Infections caused by MRSA accounted for a high proportion of the staphylococcal infections diagnosed in the ED, necessitating a rational approach to the prescription of antibiotics for infections of this type.

Effects of spilled oil on bacterial communities of mediterranean coastal anoxic sediments chronically subjected to oil hydrocarbon contamination.

The effects of spilled oil on sedimentary bacterial communities were examined in situ at 20 m water depth in a Mediterranean coastal area. Sediment collected at an experimental site chronically subjected to hydrocarbon inputs was reworked into PVC cores with or without a massive addition of crude Arabian light oil ( approximately 20 g kg(-1) dry weight). Cores were reinserted into the sediment and incubated in situ at the sampling site (20 m water depth) for 135 and 503 days. The massive oil contamination induced significant shifts in the structure of the indigenous bacterial communities as shown by ribosomal intergenic spacer analysis (RISA). The vertical heterogeneity of the bacterial communities within the sediment was more pronounced in the oiled sediments particularly after 503 days of incubation. Response to oil of the deeper depth communities (8-10 cm) was slower than that of superficial depth communities (0-1 and 2-4 cm). Analysis of the oil composition by gas chromatography revealed a typical microbial alteration of n-alkanes during the experiment. Predominant RISA bands in oiled sediments were affiliated to hydrocarbonoclastic bacteria sequences. In particular, a 395-bp RISA band, which was the dominant band in all the oiled sediments for both incubation times, was closely related to hydrocarbonoclastic sulfate-reducing bacteria (SRB). These bacteria may have contributed to the main fingerprint changes and to the observed biodegradation of n-alkanes. This study provides useful information on bacterial dynamics in anoxic contaminated infralittoral sediments and highlights the need to assess more precisely the contribution of SRB to bioremediation in oil anoxic contaminated areas.

[Troponin I values during rhabdomyolysis in elderly patients admitted to the emergency department]. / Valeurs de la troponine I au cours des rhabdomyolyses chez les personnes âgées admises aux urgences.

OBJECTIVE: The objective of this study was to assess the utility of determining serum cardiac troponin I (TcI) levels in the elderly. METHODS: During the nine-month study period, all patients older than 70 years admitted to the emergency department presenting rhabdomyolysis (defined by creatine kinase>500 IU/L) were included in this prospective descriptive study, except for those with acute coronary syndrome or pulmonary embolism. Patients were classified into two groups according to their serum TcI level:>0.15 or0.15 ng/mL group and 37 in the other group. Clinical and laboratory indicators were similar in the two groups. In contrast, significantly more patients in the TcI>0.15 ng/mL group had been treated with a curative dose of heparin (14 versus 2, p=0.01). This difference between the two groups was noted in both the emergency department and other hospital units. Serum TcI levels were not correlated with creatine kinase levels. Concordance between emergency department diagnosis and discharge diagnosis was 95%. No patient was discharged with a diagnosis of acute coronary syndrome; one patient, with a serum TcI level0. 15 ng/mL group versus 8% in the other group). Mortality at six months was higher among patients with an elevated serum TcI level, but the difference was not significant (23% versus 8%, p=0.07). CONCLUSION: This study indicated a trend toward higher mortality among patients with elevated serum TcI levels, although the factors underlying these increased concentrations remain unclear.

Adrenal axis function does not appear to be associated with hemodynamic improvement in septic shock patients systematically receiving glucocorticoid therapy.

OBJECTIVE: There is mounting evidence showing the value of low-dose corticosteroids in patients with septic shock requiring vasopressor therapy. It remains unclear whether adrenal function tests should be carried out systematically to guide the decision on glucocorticoid therapy. METHODS: The retrospective study was conducted in 52 patients in three university hospital ICUs. We included consecutive patients with catecholamine-dependent septic shock who had not received ketoconazole, glucocorticoids, or etomidate in the 24 h before the ACTH test, and who had survived to day 3 after the shock onset. All patients had a 250-microg ACTH test before systematic glucocorticoid therapy was started. Various definitions of relative adrenal insufficiency were used (based on cortisol basal level and/or change in cortisol level after ACTH stimulation). We defined hemodynamic improvement as a 50% reduction in the vasoactive agent dose in the 3 days following the initiation of glucocorticoid treatment. The relationship between the hemodynamic improvement and the results of the adrenal function tests was analyzed. RESULTS: Hemodynamic improvement occurred in 29 patients (55.8%). Baseline characteristics, sites of infection, types of micro-organisms and antibiotic management did not differ between patients with and those without hemodynamic improvement. Relative adrenal insufficiency whatever the definition was not associated with hemodynamic improvement. CONCLUSION: In catecholamine-dependent septic shock patients managed with systematic glucocorticoid therapy the results of ACTH stimulation do not predict hemodynamic improvement.

[Creatinine clearance and drug prescriptions for the elderly. A study of 419 patients older than 70 years admitted through the emergency department]. / Prise en compte de la clairance de la créatinine lors de la prescription médicamenteuse chez les sujets âgés. Etude de 419 dossiers de patients de plus de 70 ans adressés aux urgences.

INTRODUCTION: The incidence of drug-related adverse events increases with age. In approximately 20% of cases, these events necessitate hospitalization. By taking into account the physiological changes associated with aging when prescribing drugs, physicians can prevent some of these events. The objective of this study was to analyze the prescriptions written by general practitioners for elderly patients admitted to the emergency department in relation to the patient's creatinine clearance. PATIENTS AND METHODS: Of 968 consecutive patients older than 70 years, 419 underwent a plasma creatinine assay on admission and were included in this study. Creatinine clearance was calculated with Cockcroft's formula. The patients were classified into two groups according to creatinine clearance:<30 mL/min (group I) and >or=30 mL/min (group II). RESULTS: Creatinine clearance was<30 mL/min in 84 of the 419 patients (group I) and >or=30 mL/min in 335 (group II). Mean age was significantly higher in group I than in group II (87 +/- 6 vs 81 +/- 6 years, p<0.001), as was mean plasma creatinine concentration (113 +/- 23 vs 83 +/- 19 mmol/L, p<0.001), while mean weight was significantly lower (57 +/- 10 vs 69 +/- 13 kg, p<0.001. In group I, 82 drugs with precautions concerning renal function had been prescribed for 69 (82%) patients, and in group II, 331 such drugs for 174 (52%) patients. Of the 82 drugs prescribed in group I that required precaution, 47 (57%) were contraindicated or prescribed at an inappropriate dose in view of the creatinine clearance. Irrespective of pharmacokinetic parameters, the mean number of drugs taken per patient was 5 +/- 2 in group I and 6 +/-2 in group II. CONCLUSION: In prescribing drugs for elderly patients, especially those whose weight is low, careful attention should be paid to renal function.

Continuous infusion of ceftazidime in critically ill patients undergoing continuous venovenous haemodiafiltration: pharmacokinetic evaluation and dose recommendation.

INTRODUCTION: In seriously infected patients with acute renal failure and who require continuous renal replacement therapy, data on continuous infusion of ceftazidime are lacking. Here we analyzed the pharmacokinetics of ceftazidime administered by continuous infusion in critically ill patients during continuous venovenous haemodiafiltration (CVVHDF) in order to identify the optimal dosage in this setting. METHOD: Seven critically ill patients were prospectively enrolled in the study. CVVHDF was performed using a 0.6 m2 AN69 high-flux membrane and with blood, dialysate and ultrafiltration flow rates of 150 ml/min, 1 l/hour and 1.5 l/hour, respectively. Based on a predicted haemodiafiltration clearance of 32.5 ml/min, all patients received a 2 g loading dose of ceftazidime, followed by a 3 g/day continuous infusion for 72 hours. Serum samples were collected at 0, 3, 15 and 30 minutes and at 1, 2, 4, 6, 8, 12, 24, 36, 48 and 72 hours; dialysate/ultrafiltrate samples were taken at 2, 8, 12, 24, 36 and 48 hours. Ceftazidime concentrations in serum and dialysate/ultrafiltrate were measured using high-performance liquid chromatography. RESULTS: The mean (+/- standard deviation) elimination half-life, volume of distribution, area under the concentration-time curve from time 0 to 72 hours, and total clearance of ceftazidime were 4 +/- 1 hours, 19 +/- 6 l, 2514 +/- 212 mg/h per l, and 62 +/- 5 ml/min, respectively. The mean serum ceftazidime steady-state concentration was 33.5 mg/l (range 28.8-36.3 mg/l). CVVHDF effectively removed continuously infused ceftazidime, with a sieving coefficient and haemodiafiltration clearance of 0.81 +/- 0.11 and 33.6 +/- 4 mg/l, respectively. CONCLUSION: We conclude that a dosing regimen of 3 g/day ceftazidime, by continuous infusion, following a 2 g loading dose, results in serum concentrations more than four times the minimum inhibitory concentration for all susceptible pathogens, and we recommend this regimen in critically ill patients undergoing CVVHDF.

Weaning from mechanical ventilation with pressure support in patients failing a T-tube trial of spontaneous breathing.

OBJECTIVE: Evidence that PS may facilitate weaning from mechanical ventilation (MV), although not confirmed by randomized trials, prompted us to investigate whether patients could be weaned with PS after failing a T-tube trial. DESIGN AND SETTING: This was a prospective, non-randomized study in two French intensive care units. PATIENTS AND PARTICIPANTS: One hundred eighteen patients were enrolled and underwent a T-tube trial, after which 87 were extubated. Thirty-one underwent a further trial with PS, after which 21 were extubated. INTERVENTIONS: All patients under MV >24 h meeting the criteria for a weaning test underwent a 30-min T-tube trial. If this was successful, they were immediately extubated. Otherwise, a 30-min trial with +7 cm H2O PS was initiated with an individualized pressurization slope and trigger adjustment. If all weaning criteria were met, the patients were extubated; otherwise, MV was reinstated. MEASUREMENTS AND RESULTS: The extubation failure rate at 48 h did not differ significantly between the groups: 11/87 (13%) versus 4/21 (19%), P=0.39. The groups were comparable with regard to endotracheal tube diameter, MV duration, the use of non-invasive ventilation (NIV) after extubation, initial severity score, age and underlying pathology, except for COPD. A significantly higher percentage of patients with COPD was extubated after the trial with PS (8/21-38%) than after a single T-tube trial (11/87-13%) (P=0.003). CONCLUSIONS: Of the patients, 21/118 (18%) could be extubated after a trial with PS, despite having failed a T-tube trial. The reintubation rate was not increased. This protocol may particularly benefit patients who are most difficult to wean, notably those with COPD.

Influence of growth phase on the phospholipidic fatty acid composition of two marine bacterial strains in pure and mixed cultures.

This in vitro study was conducted in order to determine the effects of hydrocarbons and growth phase on the phospholipid ester-linked fatty acid composition of two marine sedimentary hydrocarbon-degrading bacteria. These two strains, namely Corynebacterium sp. and Sphingomonas sp. 2MPII, were cultivated on either a simple soluble substrate (ammonium acetate) or a hydrocarbon (respectively n-eicosane and phenanthrene). The incubations were stopped at different times corresponding to point of lag (2 days), exponential (7 days) and stationary phases (21 and 56 days). The effects of growth phase and hydrophobic substrates were successfully demonstrated by a simple index, given as the sum of saturated fatty acids divided by the sum of unsaturated fatty acids ( summation operatorSFA/ summation operatorMUFA), ranging from 1.4 to 3, 0.3 to 0.6, and 0.5 to 1.0 for Corynebacterium sp., Sphingomonas sp. 2MPII, and mixed cultures, respectively. This result was validated by a principal component analysis. In pure cultures, the phospholipid fatty acid (PLFA) composition was strongly influenced by both the carbon source and the growth phase. Nevertheless, the two strains showed different "behaviors". For 2MPII, the main PLFA composition changes were observed at 2 days while they were progressive as a function of time for Corynebacterium sp. These differences could explain the evolution of PLFAs of mixed cultures.

Use of electrospray ionization mass spectrometry for profiling of crude oil effects on the phospholipid molecular species of two marine bacteria.

We investigated the membrane lipid composition of two hydrocarbon-degrading gram-negative bacterial strains (Pseudomonas nautica IP 617 and Marinobacter hydrocarbonoclasticus) initially cultured on a soluble substrate, then on petroleum hydrocarbons, and finally taken back onto the soluble substrate. For the two strains, the growth on petroleum and the return to the initial medium showed major, but comparable, qualitative and quantitative modifications of the intact phospholipid molecular species (IPMS) composition. Furthermore, since bacterial membranes are mainly made up of phospholipids, these modifications reflected hydrocarbon assimilation, restoration abilities and membrane fluidity adaptation. The electrospray ionization mass spectrometry (ESI-MS) analysis of intact phospholipid provided some new information (e.g. sn fatty acyl chain distribution) that could not be assessed by the classical fatty acid analysis. Moreover, such information should be particularly helpful with regards to bacterial taxonomy and xenobiotic toxicity studies.

Decrease in serum procalcitonin levels over time during treatment of acute bacterial meningitis.

INTRODUCTION: The aim of this study was to describe the change in serum procalcitonin levels during treatment for community-acquired acute bacterial meningitis. METHODS: Out of 50 consecutive patients presenting with bacterial meningitis and infection at no other site, and who had received no prior antibiotic treatment, 48 had a serum procalcitonin level above 0.5 ng/ml on admission and were enrolled in the study. RESULTS: The mean age of the patients was 55 years, and mean Glasgow Coma Scale score on admission was 13. The time from symptom onset to admission was less than 24 hours in 40% of the patients, 24-48 hours in 20%, and more than 48 hours in 40%. The median (interquartile) interval between admission and initial antibiotic treatment was 160 min (60-280 min). Bacterial infection was documented in 45 patients. Causative agents included Streptococcus pneumoniae (n = 21), Neisseria meningitidis (n = 9), Listeria monocytogenes (n = 6), other streptococci (n = 5), Haemophilus influenzae (n = 2) and other bacteria (n = 2). The initial antibiotic treatment was effective in all patients. A lumbar puncture performed 48-72 hours after admission in 34 patients showed sterilization of cerebrospinal fluid. Median (interquartile) serum procalcitonin levels on admission and at day 2 were 4.5 (2.8-10.8) mg/ml and 2 (0.9-5.0) mg/ml, respectively (P < 0.0001). The corresponding values for C-reactive protein were 120 (21-241) mg/ml and 156 (121-240) mg/ml, respectively. Five patients (10%) died from noninfectious causes during their hospitalization. CONCLUSIONS: Serum procalcitonin levels decrease rapidly with appropriate antibiotic treatment, diminishing the value of lumbar puncture performed 48-72 hours after admission to assess treatment efficacy.

Effects of pure n-alkanes and crude oil on bacterial phospholipid classes and molecular species determined by electrospray ionization mass spectrometry.

Phospholipids are major components of bacterial membrane. Furthermore, the growth in vitro on xenobiotics such as n-alkanes, aromatic compounds or alkanols bring about to a bacterial membrane adaptive response. Concerning this work, we studied the membrane lipid composition of a hydrocarbon-degrading gram-positive bacterium (Corynebacterium sp.) on a soluble substrate and we detected four different phospholipid classes: phosphatidylglycerol, phosphatidylinositol, cardiolipin and acyl phosphatidylglycerol. In addition, a study of the lipid composition was performed after an in vitro culture on either pure n-alkane or crude oil. The growths on such hydrophobic substrates showed major qualitative and quantitative modifications. In the case of a growth on either heneicosane or crude oil, an increase of odd-numbered fatty acids was observed. Furthermore, the phospholipid polar head group composition was highly influenced by the crude oil addition. These modifications were, respectively, interpreted as the consequence of hydrocarbon assimilation and membrane fluidity adaptation. Finally, Corynebacterium sp. was taken back on the initial ammonium acetate substrate in order to determine its restoration abilities after a petroleum contamination.

Bacterial phospholipid molecular species analysis by ion-pair reversed-phase HPLC/ESI/MS.

This work set out to optimize the detection and separation of several phospholipid molecular species on a reversed-phase column with the use of an electrospray ionization/mass spectrometry-compatible counter-ion. An application of this technique concerned a qualitative and quantitative analysis of bacterial membrane phospholipids extracted from Corynebacterium species strain 8. The phospholipid classes of strain 8 were identified as phosphatidylglycerol, phosphatidylinositol, diphosphatidylglycerol, and a peculiar lipid compound, acyl phosphatidylglycerol. Most of the molecular species structures were elucidated, and regarding phosphatidylglycerol, the fatty acid positions were clearly determined with the calculation of the sn-2/sn-1 intensity ratio of the fatty acyl chain fragments.

Prognostic factors in acute respiratory distress syndrome: a retrospective multivariate analysis including prone positioning in management strategy.

OBJECTIVE: To investigate the prognostic factors in acute respiratory distress syndrome (ARDS) patients focusing on the use of prone positioning (PP). DESIGN AND SETTING: Retrospective study conducted in an intensive care unit of a university hospital. PATIENTS: All consecutive mechanically ventilated ARDS patients surviving on day 7 after the diagnosis of ARDS. METHODS: The study included all ARDS patients who survived more than 7 days after ARDS diagnosis between January 1995 and December 2002. Demographic and respiratory variables were collected on day 1, and the management of ARDS was analyzed during the first 7 days ( n=125). We performed a univariate analysis and a stepwise logistic regression analysis comparing survivors and nonsurvivors on day 28 and at 2 and 6 months. RESULTS: Mortality rates on day 28 and at 2 and 6 months were 21.6%, 32%, and 44% respectively. A SAPS II score less than 49, McCabe score, and the use of PP introduced in the first 7 days of ARDS management appeared to be independently correlated with a decrease in mortality. CONCLUSIONS: The SAPS II score, the McCabe score, and use of PP are independently correlated with the outcome in ARDS patients.