Procedure volume is one determinant of centre effect in mechanically ventilated patients.

Survival rates vary significantly between intensive care units, most notably in patients requiring mechanical ventilation (MV). The present study sought to estimate the effect of hospital MV volume on hospital mortality. We included 179,197 consecutive patients who received mechanical ventilation in 294 hospitals. Multivariate logistic regression models with random intercepts were used to estimate the effect of annual MV volume in each hospital, adjusting for differences in severity of illness and case mix. Median annual MV volume was 162 patients (interquartile range 99-282). Hospital mortality in MV patients was 31.4% overall, 40.8% in the lowest annual volume quartile and 28.2% in the highest quartile. After adjustment for severity of illness, age, diagnosis and organ failure, higher MV volume was associated with significantly lower hospital mortality among MV patients (OR 0.9985 per 10 additional patients, 95% CI 0.9978-0.9992; p = 0.0001). A significant centre effect on hospital mortality persisted after adjustment for volume effect (p < 0.0001). Our study demonstrated higher hospital MV volume to be independently associated with increased survival among MV patients. Significant differences in outcomes persisted between centres after adjustment for hospital MV volume, supporting a role for other significant determinants of the centre effect.

Characterization of Pt nanoparticles deposited onto carbon nanotubes grown on carbon paper and evaluation of this electrode for the reduction of oxygen.

Multiwalled carbon nanotubes (MWCNTs) were grown on the fibers of a commercial porous carbon paper used as carbon-collecting electrodes in fuel cells. The tubes were then covered with Pt nanoparticles in order to test these gas diffusion electrodes (GDEs) for oxygen reduction in H2SO4 solution and in H2/O2 fuel cells. The Pt nanoparticles were characterized by cyclic voltammetry, transmission electron microscopy, and X-ray photoelectron spectroscopy. The majority of the Pt particles are 3 nm in size with a mean size of 4.1 nm. They have an electrochemically active surface area of 60 m2/g Pt for Pt loadings of 0.1-0.45 mg Pt/cm2. Although the electroactive Pt surface area is larger for commercial electrodes of similar loadings, Pt/MWCNT electrodes largely outperform the commercial electrode for the oxygen reduction reaction in GDE experiments using H2SO4 at pH 1. On the other hand, when the same electrodes are used as the cathode in a H2/O2 fuel cell, they perform only slightly better than the commercial electrodes in the potential range going from approximately 0.9 to approximately 0.7 V and have a lower performance at lower voltages.

[Plasma exchanges as treatment of severe acute immune thrombocytopenic purpura]. / Echanges plasmatiques dans les formes graves de purpura thrombopénique immunologique aigu.

INTRODUCTION: High dose steroids and intravenous immunoglobulins are the gold treatment of acute immune thrombocytopenic purpura, before splenectomy for severe and refractory forms of the disease. Authors report two cases of severe acute refractory immune thombocytopenia with a dramatic response to plasma exchanges. EXEGESIS: The first case was an idiopathic form, complicated by hemorragic peritoneal effusion. After failure of steroids, intravenous immunoglobulins and splenectomy and 2 courses of rituximab, plasmapheresis normalized in 3 days platelet count. In the second observation, ITP was associated to systemic lupus with antiphospholipids antibodies and multivisceral failure, despite steroids and intravenous immunoglobulins. After 3 plasma exchanges, platelet count was normalized, and the patient is under remission after 24 months follow-up. CONCLUSION: Plasmapheresis must be evaluated as an emergency treatment in refractory forms of acute immune thrombocytopenic purpura.

Reliability of the bronchoscopic protected catheter brush in intubated and ventilated patients.

The reliability of a bronchoscopic protected catheter brush (BPCB) in the diagnosis of lower respiratory tract infection was studied in 17 intubated and ventilated patients, including seven patients free from such infection (group 1) and ten patients with suspected infection (group 2). A first sample was obtained in the lower trachea by aspiration through the fiberoptic bronchoscope and a second in a distal bronchus by the BPCB procedure. In group 1, all BPCB cultures were sterile, although lower tracheal cultures yielded two or more bacterial species, showing that uncontaminated specimens can be obtained by the BPCB procedure. In three patients of group 2, BPCB cultures remained sterile as a nonbacterial pulmonary disease was certified by open lung biopsy. In seven patients from group 2, BPCB cultures yielded all of the organisms isolated simultaneously by reference methods (ie, cultures of blood or pleural fluid, serologic tests, and open lung biopsy). In two of these patients, contamination of the BPCB specimens was ascertained by the reference method bacterial results. In this study the BPCB procedure was able to obtain uncontaminated specimens in intubated and ventilated patients and was mainly accurate in identifying the bacterial etiologic agents of lower respiratory tract infections.

Alteration of the T cell repertoire after bone marrow transplantation.

We investigated T cell receptor (TCR) alpha/beta and gamma/delta repertoire reconstitution after autologous and allogeneic bone marrow transplantation (BMT) in humans using 13 monoclonal antibodies directed at constant and variable regions of the TCR. The TCR gamma/delta repertoire was studied kinetically during the first month and then 1 year post-BMT whereas alpha/beta peripheral blood T lymphocytes (PBTL) were studied within the first 3 months and 1 year post-BMT. Through these two studies, we found 7 of 26 patients with over-represented TCR gamma/delta subsets during the early period post-BMT. Moreover, during this period the V gamma 9V delta 2 frequency among gamma/delta T cells was found to be higher than among normal donors. Study on TCR alpha/beta T cells also revealed abnormally expanded V-specific subset (5 of 10 patients within 3 months following BMT) demonstrating that repertoire alteration early after BMT is a general phenomenon concerning potentially all T cell subsets. More surprisingly, the alpha/beta T cell repertoire was also found to be altered late after BMT (7 of 15 patients after 1 year post-BMT presented one or more overepresented alpha/beta TCR subset). These alterations of TCR combinatorial diversity should be taken into account in understanding the immunological status of patients after BMT.

Nosocomial infections: prospective survey of incidence in five French intensive care units.

OBJECTIVE: To assess the incidence and to evaluate the feasibility of inter-unit continuous surveillance of intensive care unit (ICU)-acquired infections. DESIGN: Prospective multicentre, longitudinal, incidence survey. SETTING: Five ICUs in university hospitals in western France. PATIENTS: All patients admitted to the ICU during two 3-month periods (1994-1995). MEASUREMENTS AND RESULTS: The main clinical characteristics of the patients, ICU-acquired infections, length of exposure to invasive devices and the micro-organisms isolated were analysed. The study included 1589 patients (16970 patient-days) and the infection rate was 21.6 % (13.1 % of patients). The ventilator-associated pneumonia rate was 9.6 %, sinusitis 1.5 %, central venous catheter-associated infection 3.5 %, central venous catheter-associated bacteraemia 4.8 %, catheter-associated urinary tract infection 7.8 % and bacteraemia 4.5 %. The incidence density rate of ICU-acquired infections was 20.3% patient-days. Ventilator-associated pneumonia and sinusitis rates were 9.4 and 1.5% ventilation-days, respectively. Central venous catheter-associated infection and central venous catheter-associated bacteraemia rates were 2.8 and 3.8% catheter-days, respectively. The catheter-associated urinary tract infection rate was 8.5% urinary catheter-days and the bacteraemia rate 4.2% patient-days. Six independent risk factors for ICU-acquired infection were found by stepwise logistic regression analysis: absence of infection on admission, age > 60 years, length of stay, mechanical ventilation, central venous catheter and admission to one particular unit. A total of 410 strains of micro-organisms were isolated, 16.8 % of which were Staphylococcus aureus (58.0% methicillin-resistant). CONCLUSION: This prospective study using standardised collection of data on the ICU-acquired infection rate in five ICUs identified six risk factors. It also emphasized the difficulty of achieving truly standardised definitions and methods of diagnosis of such infections.

Influence of patients' age on survival, level of therapy and length of stay in intensive care units.

The influence of patients' age on survival, level of therapy and length of stay was analyzed from data collected in 792 consecutive admissions to eight intensive care units. Mortality rate increased progressively with age; over 65 years of age, it was more than double that of patients under 45 years (36.8% versus 14.8%). However, mortality rate in patients over 75 years was equal to that observed in the 55 to 59 years group. There was a significant relationship between age and acute physiology score (APS) and the influence of age upon outcome decreased when APS increased. The number of TISS (therapeutic intervention scoring system) points delivered to patients increased slightly but significantly with age (r = 0.14). Standard care was responsible for the main part of this increase. Both in survivors and in non-survivors the length of stay was not different comparing the stay of the oldest patient with that of the younger age groups. We conclude that, in ICU patients, age is an important factor of prognosis but not as important as the severity of illness, and that there is no major difference in outcome of patients over 65 years of age compared to the entire study group of ICU patients.

Diagnosis of brain death using two-phase spiral CT.

PURPOSE: The purpose of this study was to determine the utility of spiral CT in the diagnosis of brain death. METHODS: Spiral CT was evaluated prospectively in 14 brain-dead patients and in 11 healthy subjects. A two-phase protocol was used. Twenty seconds after intravenous injection of a nonionic iodinized contrast medium, the CT table was drawn through the gantry at a rate of 10 mm/s while scanning was in progress. The second scanning phase was started automatically a mean of 54 seconds later, using the same parameters. Opacification or absence of opacification of carotid, vertebral, and basilar arteries and intracerebral veins was ascertained for each image in both phases. The diagnosis of brain death was confirmed by elecroencephalography (n = 7), angiography (n = 5), or both (n = 2). Statistical analysis with the Fisher exact test enabled us to compare the brain-dead patients with the healthy control subjects. RESULTS: In brain death, the pericallosal and terminal arteries of the cortex did not opacify during the two phases of spiral CT, whereas the superficial temporal arteries were always visible. The internal cerebral veins, the great cerebral vein, and the straight sinus did not opacify, whereas the superior ophthalmic veins were visible on both sides 13 times. For each vessel type, specificity was 100% for nonvascular opacification criteria on the right and left sides. CONCLUSION: Two-phase spiral CT can demonstrate the absence of intracerebral blood flow in brain death.

Prospective evaluation of the protected specimen brush for the diagnosis of pulmonary infections in ventilated newborns.

The precise diagnosis of lower respiratory tract infection in the critically ill newborn remains a difficult challenge. The bronchoscopic protected specimen brush (PSB) is a reliable method in intubated adults. Because the bronchoscopic procedure is not generally available for young children, Zucker proposed a blind technique for introducing the PSB into the distal airways. His results were promising but were not compared with any bacteriologic reference method. Therefore, we wanted to evaluate this technique in comparison with the open lung biopsy (OLB) when it could be ethically accomplished. Eleven PSB were collected simultaneously with an OLB. The sensitivity of the PSB procedure was 100%, its specificity 88%, its positive predictive value 66%, and its negative predictive value 100%. There were no complications secondary to the PSB procedure. In this short study, the PSB procedure using a blind technique is safe and feasible to obtain uncontaminated specimens in intubated and ventilated newborns, and is largely accurate in identifying the bacterial etiologic agent of lower respiratory tract infection.

[Completeness of ICU activity reports sent to French healthcare authorities]. / Exhaustivité des résumés d'unité médicale adressés aux départements d'information médicale.

INTRODUCTION: Hospital units report on their inpatient care activity by writing yearly activity reports, which are used by their Medical Information Department (MID) to develop standardized summaries for communication to healthcare authorities. The data are categorized by uniform patient groups and used to describe inpatient care activity and to guide resource allocation. The objective of this study was to evaluate the completeness of activity reports from intensive care units (ICUs) in France. METHODS: Activity reports sent in 1998 and 1999 by French ICUs participating in the study were collected using dedicated abstracting software supplied to the relevant MIDs. Completeness of data in the activity reports was evaluated, with special attention to the SAPSII score, Omega rating of ICU procedures according to the Classification of Medical Procedures, and primary and secondary diagnoses. RESULTS: The 106 ICUs that volunteered for the study reported data on 107,652-hospital stays. Mean age and SAPSII were 55 +/- 21 years and 35 +/- 21 years, respectively. Mean ICU and hospital lengths of stay were 6.2 +/- 12.4 and 16.1 +/- 21.6 days, respectively. Mean ICU and hospital mortality rates were 15% and 19%. The SAPSII and Omega procedures were reported for 81% and 80% of stays, respectively. The SAPSII and Omega procedures were calculated or coded in 94% (100/106) and 96% (102/106) of ICUs, respectively. Mean number of Omega procedures was 4.3+/-3.9. However, only 5% (5/106) of ICUs entered the SAPSII for every stay, and 21% (22/106) of ICUs failed to enter the SAPSII for over 20% of stays. Similarly, 53% (56/106) of ICUs rated no more than five Omega procedures on average per stay. The primary diagnosis was reported for all stays, and the mean number of secondary diagnoses was 3.5 +/- 3.8. In 80% (86/106) of ICUs, no more than five secondary diagnoses were coded on average per stay. CONCLUSION: The analysis of this national database shows that data communicated to the MIDs and therefore to the healthcare authorities, are incomplete regarding SAPSII, ICU procedures, treatment intensity, and diagnoses. This may lead to the underestimation of ICU activity and resource needs, particularly if the SAPSII and selected procedures identified as markers for high-intensity critical care are used in the future.

[Administration of tobramycin aerosols in patients with nosocomial pneumonia: a preliminary study]. / Administration d'aérosols de tobramycine chez des patients ayant une pneumopathie nosocomiale: étude préliminaire.

OBJECTIVE: The aim of this study was to assess renal and respiratory tolerance of aerosolized tobramycin in intubated and mechanically ventilated patients with nosocomial pneumonia. PATIENTS AND METHODS: This was a multicenter, randomized, double-blind, placebo controlled study. Thirty-eight mechanically ventilated patients with documented nosocomial pneumonia were included. Patients treated with intravenous betalactam and tobramycin were randomly allocated to receive aerosolized tobramycin (6 mg/kg/day, n = 21) or placebo (n = 17). The aerosol was administered via a pneumatic nebulizer once a day for 5 days. RESULTS: Respiratory tolerance was good in all but two patients. No acute renal failure occurred. By day 10, 7 patients in the tobramycin group (35%) had been extubated versus 3 in the placebo group (18.5%, p = 0.18). By day 28, 6 patients had died (2 in the tobramycin group and 4 in the placebo group, p = 0.23). CONCLUSION: Aerosolized tobramycin was well tolerated in ventilated patients with documented nosocomial pneumonia.

Contribution of the ethics committee of the French society of intensive care medicine to a scenario for the implementation of organ donation after Maastricht III-type cardiac death in France.

French law allows organ donation after death due to cardiocirculatory arrest. In the Maastricht classification, type III non-heart-beating donors are those who experience cardiocirculatory arrest after the withdrawal of life-sustaining treatments. French authorities in charge of regulating organ donation (Agence de la Biomédecine, ABM) are considering organ collection from Maastricht type III donors. We describe a scenario for Maastricht type III organ donation that fully complies with the ethical norms governing care to dying patients. That organ donation may occur after death should have no impact on the care given to the patient and family. The dead-donor rule must be followed scrupulously: the organ retrieval procedure must neither cause nor hasten death. The decision to withdraw life-sustaining treatments, withdrawal modalities, and care provided to the patient and family must adhere strictly to the requirements set forth in patient-rights legislation (the 2005 Léonetti law in France) and should not be influenced in any way by the possibility of organ donation. A major ethical issue regarding the family is how best to transition from discussing treatment-withdrawal decisions to discussing possible organ retrieval for donation should the patient die rapidly after treatment withdrawal. Close cooperation between the healthcare team and the organ retrieval team is crucial to minimize the distress of family members during this transition. Modalities for implementing Maastricht type III organ donation are discussed here, including the best location for withdrawing life-sustaining treatments (operating room or intensive care unit).

[Multicenter survey on ventilator-associated pneumonia prevention in intensive care]. / Enquête multicentrique sur l'application des recommandations de prévention des pneumopathies acquises sous ventilation mécanique en réanimation.

OBJECTIVE: Ventilator-associated pneumonia (VAP) is the most common hospital-acquired infection in intensive care unit (ICU). The aim of the study was to evaluate the follow-up of the guidelines for VAP prevention. STUDY DESIGN: Retrospective, observational and multicenter study. PATIENTS AND METHODS: During one year, all patients with mechanical ventilation over 48 hours were included in the CCLIN-Ouest Network. The demographic characteristics of the patients, the use of specific protocol for VAP prevention and the density of incidence of VAP were recorded. The use of a protocol for preventing VAP (absence, incomplete, complete and care bundle (i.e. complete prevention of VAP with weaning mechanical protocol and sedation protocol)) was collected. RESULTS: 26 ICU with 5742 patients were included. Ten ICU (38%; 2595 patients) had no protocol for VAP prevention, eight ICU (31%; 1821 patients) had an incomplete protocol, five ICU (19%; 561 patients) had a complete protocol and three ICU (12%; 765 patients) had a care bundle. The density of incidence of VAP was 14.8‰ (Interquartile range [IQR]: 10.2-0.1) for no protocol group, 15.6‰ [IQR: 12.6-6.2] for incomplete protocol group, 11.0‰ [IQR: 9.1-14.0] for complete protocol group and 12.9‰ [5-7,7-9,9-12] for care bundle group (P=0.742). CONCLUSIONS: The compliance to prevention of VAP was poor. Proposals for improving practice are discussed.

Can procalcitonin help identify associated bacterial infection in patients with severe influenza pneumonia? A multicentre study.

PURPOSE: To determine whether procalcitonin (PCT) levels could help discriminate isolated viral from mixed (bacterial and viral) pneumonia in patients admitted to the intensive care unit (ICU) during the A/H1N1v2009 influenza pandemic. METHODS: A retrospective observational study was performed in 23 French ICUs during the 2009 H1N1 pandemic. Levels of PCT at admission were compared between patients with confirmed influenzae A pneumonia associated or not associated with a bacterial co-infection. RESULTS: Of 103 patients with confirmed A/H1N1 infection and not having received prior antibiotics, 48 (46.6%; 95% CI 37-56%) had a documented bacterial co-infection, mostly caused by Streptococcus pneumoniae (54%) or Staphylococcus aureus (31%). Fifty-two patients had PCT measured on admission, including 19 (37%) having bacterial co-infection. Median (range 25-75%) values of PCT were significantly higher in patients with bacterial co-infection: 29.5 (3.9-45.3) versus 0.5 (0.12-2) µg/l (P < 0.01). For a cut-off of 0.8 µg/l or more, the sensitivity and specificity of PCT for distinguishing isolated viral from mixed pneumonia were 91 and 68%, respectively. Alveolar condensation combined with a PCT level of 0.8 µg/l or more was strongly associated with bacterial co-infection (OR 12.9, 95% CI 3.2-51.5; P < 0.001). CONCLUSIONS: PCT may help discriminate viral from mixed pneumonia during the influenza season. Levels of PCT less than 0.8 µg/l combined with clinical judgment suggest that bacterial infection is unlikely.

[Multiple organ failure and disseminated adenoviral infection]. / Défaillance multiviscérale et infection disséminée à adénovirus.

BACKGROUND: Peripheral blood stem cell transplantation is a frequent option, especially for patients with hematological malignancies. CASE REPORTS: A first patient received this treatment for acute myeloblastic leukemia, the second for Richter's syndrome (follicular lymphoma). In both cases, allograft (unrelated donor, non myeloablative conditioning) was followed by graft versus host disease (GVH) requiring an immunosuppressive treatment. Respectively 15 and three months after graft, these two patients presented with multiple organ failure including very severe hepatic dysfunction. The diagnosis was made according to positive blood PCR, positive BAL, and hepatic histological findings. DISCUSSION: Adenoviruses, frequent in pediatrics, can be responsible for extremely severe infections among immunocompromised adults. T lymphocyte depletion plays a key role. CONCLUSION: Adenoviral infections can be fatal among immunocompromised patients. Diagnostic improvement should lead to early treatment, which however, remains to be clearly defined.

[ICU performance: results of a French study involving 80,000 ICU stays]. / Performance en réanimation: résultats du PHRC Sfar-SRLF.

OBJECTIVE: The Standard Mortality Ratio (SMR), comparing the observed in-hospital mortality to the predicted, may measure the intensive care units (ICU) performance. STUDY DESIGN: Multicentric retrospective national study. METHODS: A probability model using a severity score such SAPS II calculated the predicted mortality rate. A national French study has been undertaken to compare the SMR of ICUs and looked for explanation. RESULTS: One hundred six units, 34 were medical (32%), 18 surgical (17%) and 57 medical/surgical (51%) participated to the study. Forty-six ICUs (43%) were located in teaching hospitals. The SMR of the 87,099 stays was 0.84 (0.82-0.85). The SMR of ICUs varied from 0.41 to 1.55. Ten units had a SMR>0.85, which suggested a low performance. They had more stays for cardiovascular failures, as compared with others. The best units (SMR<0.82) had more stays for drug overdose. The SMR increased with the number of organ failures, from 0.47 with zero failure to 1.11 with 4 or more organ failures. The stays with cardiovascular failure, either unique or associated, had a higher SMR. The 7935 stays with a drug overdose had a SMR of 0.12 (0.10-0.14), which suggested a bad calibration of the model in theses cases. CONCLUSION: The case mix must be taken in account when comparing the ICUs performance by the mean of SMR, particularly when the units admitted a lot of drug overdoses.

Hemodynamic pattern in anaphylactic shock with cardiac arrest.

A 41-yr-old man developed anaphylactic or anaphylactoid shock 9 min after infusion of a modified fluid gelatin. The hemodynamic effects of shock from its onset were studied: fall in mean arterial pressure (MAP) and systemic vascular resistance index (SVRI), increase in cardiac index (CI) and stroke index (SI). When the infusion was stopped, a few min after the onset of shock, wedge pressure (WP) fell sharply and the patient experienced cardiac arrest without previous arrhythmia or other ECG anomaly, thus demonstrating the importance of maintaining the left ventricular filling pressure at a normal level in the course of anaphylactic shock.

[A prognostic study of 238 cases of chest trauma. Influence of the delay in admission in an intensive care unit (author's transl)]. / Etude pronostique de 238 traumatisés thoraciques. Influence du retard à l'admission dans un service de réanimation.

238 cases of chest trauma were studied according to the same protocol. With this protocol we can perform on the one hand a comprehensive study of the prognosis according to the thoracic lesions and associated lesions and on the other hand a prognostic study according to the delay of admission in a intensive care unit. All our data show that the most serious lesion is the pulmonary contusion and that mortality increases if an associated lesion is present, according to its nature. On the other hand a comparison was performed between the patients directly admitted in the intensive care unit (GI) and the patients hospitalized after a delay (GII) this comparison shows that in G II patients the rate of complications was higher, the mortality more important and respiratory sequelae more frequent than for patients of GI with thoracic lesions of the same importance or less important. These data show that an early admission of chest trauma patients in an intensive care unit is desirable and that the duration of this hospitalization must be at least 3 or 6 days.