Coupled temperature and γ-radiation effect on silica-based optical fiber strain sensors based on Rayleigh and Brillouin scatterings.

Coupled temperature and γ-ray influence on Brillouin (PPP-BOTDA) and Rayleigh (TW-COTDR) scatterings are quantified. Aging tests of these distributed strain measuring systems are performed on-line, up to 1 MGy, at room temperature, 80  ∘C, 100  ∘C and 120  ∘C. Brillouin and Rayleigh frequency shifts remain identical regardless of the temperature: 3 MHz (2 MHz) and 7 GHz (3 GHz) for Ge-doped (respectively F-doped) fiber at 1 MGy. Meanwhile, radiation-induced attenuation is diminished because of the higher temperature; hence, the maximal distance range is less deteriorated. These tests help to explain the origin of the Brillouin frequency shift under γ-rays, with an acoustic velocity variation of about 1 m/s in 1 MGy irradiated samples.

[Hemodynamic monitoring in the critically patient. Recomendations of the Cardiological Intensive Care and CPR Working Group of the Spanish Society of Intensive Care and Coronary Units]. / Monitorización hemodinámica en el paciente crítico. Recomendaciones del Grupo de Trabajo de Cuidados Intensivos Cardiológicos y RCP de la Sociedad Española de Medicina Intensiva, Crítica y Unidades Coronarias.

Hemodynamic monitoring offers valuable information on cardiovascular performance in the critically ill, and has become a fundamental tool in the diagnostic approach and in the therapy guidance of those patients presenting with tissue hypoperfusion. From introduction of the pulmonary artery catheter to the latest less invasive technologies, hemodynamic monitoring has been surrounded by many questions regarding its usefulness and its ultimate impact on patient prognosis. The Cardiological Intensive Care and CPR Working Group (GTCIC-RCP) of the Spanish Society of Intensive Care and Coronary Units (SEMICYUC) has recently impulsed the development of an updating series in hemodynamic monitoring. Now, a final series of recommendations are presented in order to analyze essential issues in hemodynamics, with the purpose of becoming a useful tool for residents and critical care practitioners involved in the daily management of critically ill patients.

Bioreactance is not reliable for estimating cardiac output and the effects of passive leg raising in critically ill patients.

BACKGROUND: Bioreactance estimates cardiac output in a non-invasive way. We evaluated the ability of a bioreactance device (NICOM®) to estimate cardiac index (CI) and to track relative changes induced by volume expansion. METHODS: In 48 critically ill patients, we measured CI estimated by the NICOM® device (CINicom) and by transpulmonary thermodilution (CItd, PiCCO2™ device) before and after a 500 ml saline infusion. Before volume expansion, we performed a passive leg raising (PLR) test and measured the changes it induced in CINicom and in pulse contour analysis-derived CI. RESULTS: Considering the values recorded before PLR and before and after volume expansion (n=144), the bias (lower and upper limits of agreement) between CItd and CINicom was 0.9 (-2.2 to 4.1) litre min(-1) m(-2). The percentage error was 82%. There was no significant correlation between the changes in CItd and CINicom induced by volume expansion (P=0.24). An increase in CI estimated by pulse contour analysis >9% during the PLR test predicted fluid responsiveness with a sensitivity of 84% (95% confidence interval 60-97%) and a specificity of 97% (95% confidence interval 82-100%). The area under the receiver operating characteristic curve constructed to test the ability of the PLR-induced changes in CINicom in predicting fluid responsiveness did not differ significantly from 0.5 (P=0.77). CONCLUSIONS: The NICOM® device cannot accurately estimate the cardiac output in critically ill patients. Moreover, it could not predict fluid responsiveness through the PLR test.

[Assessment of cardiovascular preload and response to volume expansion]. / Valoración de la precarga y la respuesta cardiovascular al aporte de volumen.

Volume expansion is used in patients with hemodynamic insufficiency in an attempt to improve cardiac output. Finding criteria to predict fluid responsiveness would be helpful to guide resuscitation and to avoid excessive volume effects. Static and dynamic indicators have been described to predict fluid responsiveness under certain conditions. In this review we define preload and preload-responsiveness concepts. A description is made of the characteristics of each indicator in patients subjected to mechanical ventilation or with spontaneous breathing.

Differential time to positivity of blood cultures: a valid method for diagnosing catheter-related bloodstream infections in the intensive care unit.

PURPOSE: The validation in critical patients with short-term catheters of a method for diagnosing catheter-related bloodstream infection (CR-BSI), based on the differential time to positivity (DTP) of blood cultures. METHODS: Patients suspected of having CR-BSI were included. Two peripheral vein blood cultures and a catheter hub blood culture were simultaneously carried out. The responsible catheter was removed and tip cultured. Times to positivity of all blood cultures were automatically registered. CR-BSI was diagnosed when all the cultures were positive for the same microorganism and DTP≥120 min. This diagnosis was compared with the one obtained using the standard method. RESULTS: 226 cases suspected of CR-BSI were analyzed during a 20-month period. A total of 19 removed catheters were associated with CR-BSI. Seven cases of polymicrobial cultures (4 with CR-BSI) were discarded from the final analysis due to the impossibility of determining the time to positivity for each individual microorganism. Using the DTP method, 12 out of 15 CR-BSI cases were diagnosed (sensitivity 80%, specificity 99%, PPV 92%, NPV 98%). In a ROC curve, we found a cut-off value of 17.7 h in positivity of hub blood cultures that may be useful for diagnosing CR-BSI. CONCLUSION: DTP can be a valid method for CR-BSI diagnosis in critically ill patients, avoiding unnecessary catheter withdrawal.

Reduction in catheter-related bloodstream infections in critically ill patients through a multiple system intervention.

In this study, we aimed to determine the utility of a multiple system intervention to reduce catheter-related bloodstream infections (CR-BSI) in our intensive care unit (ICU). A prospective cohort study was undertaken in the medical and surgical ICU at a university hospital. We applied five measures: educational sessions about inserting and maintaining central venous catheters, skin cleaning with chlorhexidine, a checklist during catheter insertion, subclavian vein insertion and avoiding femoral insertion whenever possible, and removing unnecessary catheters. We determined the rate of CR-BSI per 1,000 catheter-days during the intervention (March to December 2007) and compared it with the rate during the same period in 2006 in which we applied only conventional preventive measures. CR-BSI was defined as the recovery of the same organism (same species, same antibiotic susceptibility profile) from catheter tip and blood cultures. We registered 4,289 patient-days and 3,572 catheter-days in the control period and 4,174 patient-days and 3,296 catheter-days in the intervention period. No significant differences in the number of patients with central venous catheters during the two periods were observed: catheters were used in 81.5% of patients during the control period and in 80.6% of patients during the intervention period. During the control period, 24 CR-BSI were diagnosed (6.7/1,000 catheter-days); during the intervention period, 8 CR-BSI were diagnosed (2.4/1,000 catheter-days) (relative risk 0.36; 95% confidence interval [CI] 0.16 to 0.80; p = 0.015). Nurses interrupted the procedure to correct at least one aspect when completing the checklist in 17.7% of insertions. In conclusion, a multiple system intervention applying evidence-based measures reduced the incidence of CR-BSI in our ICU.

Sympathetic nervous system activation in postextrasystolic potentiation: role of catecholamine release in enhancement of ventricular function.

The role of catecholamines in postextrasystolic potentiation was assessed in 30 patients during continuous coupled right ventricular pacing. Hemodynamic data were recorded in 15 patients (group 1); in the other 15 patients (group 2), coronary blood flow and metabolic variables, including catecholamines, were measured. Data were recorded in the control state and after 10 minutes of coupled pacing. Both groups had similar control pulse rates and mean aortic pressures: these variables decreased abruptly by 32 beats/min and 12 mm Hg, respectively, (p less than 0.001 for each) after the initiation of coupled pacing. In group 1, all indexes of left ventricular function and contractility increased during coupled pacing (p less than 0.001 for each), thus confirming postextrasystolic potentiation. In group 2, coupled pacing increased coronary blood flow, myocardial oxygen consumption and free fatty acid uptake (p less than 0.001 for each) but not lactate extraction. Plasma epinephrine was unchanged, but norepinephrine levels increased in arterial (421 +/- 27 to 576 +/- 41 ng/liter) and coronary sinus plasma (611 +/- 46 to 836 +/- 46 ng/liter) (p less than 0.001 for both). Indirectly calculated norepinephrine release within the myocardium increased from 25.6 +/- 2.8 to 39.7 +/- 5.2 ng/min (SEM) (p less than 0.05), suggesting a sympathetic nervous system activation. It is argued that coupled pacing acutely lowered mean aortic pressure, leading to baroreflex sympathetic activation which may contribute to augmented cardiac contractility in postextrasystolic potentiation.

Quantitative analysis of BRCA1, BRCA2 and Hmsh2 mRNA expression in colorectal Lieberkühnien adenocarcinomas and matched normal mucosa: relationship with cellular proliferation.

The human DNA mismatch repair gene hMSH2 is involved in the development of sporadic and hereditary nonpolyposis colorectal cancer. An increased risk of colorectal cancer has also been suggested in BRCA1 and BRCA2 mutation carriers. To address the relationship between the expression level of these genes and colorectal tumorigenesis, we studied BRCA1, BRCA2 and hMSH2 mRNA expression by real-time quantitative RT-PCR in 72 colorectal Lieberkühnien adenocarcinomas and matched normal mucosa. We investigated the relationship between mRNA levels and various clinicopathological parameters. The mean expression of BRCA1 3' and BRCA2 3' (mRNA pool), BRCA1 ex11 (with exon 11), BRCA2 ex12 (with exon 12) and hMSH2 mRNAs were increased in tumor samples. BRCA1 and BRCA2 mRNAs expressions were altered according to colon tumor site: BRCA1 3' and BRCA2 3' mRNAs levels were highest, respectively, in the right colon and left colon. No difference in hMSH2 mRNA levels was detected in relation to clinicopathological parameters. The mean SPF value was significantly higher in tumor than in non-tumor colonic tissue, and a high SPF value was correlated with high BRCA2 mRNA levels. BRCA2 3' mRNA levels tended to decrease as the Dukes' stage increased. In conclusion, the mechanisms of colorectal carcinogenesis seem to differ according to the right or left position of the tumor.

Circulating immune complexes in patients with gram negative septic shock.

In order to explain complement components abnormalities observed during septic shock, circulating immune complexes (C.I.C.) were searched for in sera from 34 patients with gram negative sepsis by two different methods: polyethylene glycol precipitation test based on physical properties of C.I.C. and C1q deviation test based on the property of radiolabelled C1q to react with C.I.C. Serum immunoglobulins (IgG, IgA, IgM) and complement components (C1q, C3, C4) levels were simultaneously determined. Seventeen patients with minimal haemodynamic abnormalities had normal or increased levels (except C4 at 62% of normal) and in eleven cases both tests for C.I.C. were simultaneously positive. Seventeen patients with severe septic shock had a decrease in IgG, IgM C1q, C3 and C4 and none had both tests for C.I.C. simultaneously positive (P less than 10(-4)). The disappearence of C.I.C. in patients with severe septic shock associated with evidence of complement activation suggests their involvement in the pathogenesis of septic shock in man.

Decreased plasma epinephrine concentrations after glucose ingestion in humans.

Plasma levels of norepinephrine (NE), epinephrine (E), immunoreactive insulin (IRI), and glucose were measured in six healthy volunteers after glucose consumption and in six volunteers after a water solution. Ingestion of the glucose (100 g) solution significantly decreased E levels from 46.7 +/- 8.0 to 20.8 +/- 1.9 pg/mL (P less than 0.01). Three hours after the glucose ingestion, plasma E levels nearly returned to basal values. Plasma IRI and glucose levels peaked at 45 minutes after glucose consumption (P less than 0.01), then declined toward basal values. Plasma NE levels were unaffected by glucose consumption. There were no changes in glucose, IRI, NE, or E levels in the control group. These results suggest that E behaves as a counter-regulatory hormone to insulin under stimulation by glucose.

Three treatment schemes with colloidal bismuth subcitrate (Q-ULCER) in peptic ulcer with Helicobacter pylori.

BACKGROUND: Since the discovery, several decades ago, of the infection of the gastric mucosa with Helicobacter pylori and its association with chronic antral gastritis and peptic ulcer, the treatment of ulcer illness has recently been revolutionized. METHODS: In this study, the clinical effectiveness of three schemes of treatment with colloidal bismuth subcitrate (CBS) were compared. Fifty-three patients suffering from gastroduodenal peptic ulcer with Helicobacter pylori were distributed randomly into three groups. Group I (n = 17) received 240 mg CBS every 12 h for 6 weeks. Group II (n = 17) received 240 mg CBS every 12 h for 6 weeks, pus metronidazole 500 mg every 8 h plus tetracycline 500 mg every 8 h for 10 days. Group III (n = 19) received 240 mg CBS every 12 h for 6 weeks, plus metronidazole 500 mg every 8 h plus amoxicillin 750 mg every 12 h for 10 days. A duodenoscopy investigation with antrum biopsy for a morphologic study and detection of the germ was carried out by means of urease test and histological study (Warthin-Sarry and hematoxylin-eosin). RESULTS: The three schemes of treatment were effective for ulcerous healing with 70.5%, 82.3%, and 78.2%, respectively, without significant differences. The highest clearing index (52.6%) was obtained in group III. CONCLUSIONS: With these treatments, the Helicobacter pylori eradication was only observed in 47.3% of the patients studied.

[Osteochondroma of the atlantooccipital joint. Extreme lateral transcondylar approach. A case description]. / Osteocondroma de la articulación atlantoccipital. Abordaje extremo lateral transcondilar. A propósito de un caso.

INTRODUCTION: We describe a patient diagnosed as suffering from a skull base osteochondroma which affected the atlantooccipital joint and originated in the occipital condyle. It also displayed a growth toward the foramen magnum, which was resected using an extreme lateral transcondylar approach. CASE REPORT: Patient aged 35, with a one year history of vertiginous seizures and unsteady gait, associated with cervical pain that irradiated to the right upper extremity, dysphagia, changes in the tone of the voice and distal numbness of the four extremities. The patient was made to lie in the three quarter prone position and an incision was made in the skin from the C3 spinous apophysis to a point 2 cm below the end of the mastoid process, in relation with the transversal apophysis of C1. The intervention continued with early identification and rotation of the vertebral artery; total resection of the tumour (osteochondroma) with its base in the right occipital condyle and growth toward the foramen magnum, in which the greater resection of the posteromedial third of the condyle is included. CONCLUSIONS: The location of osteochondromas can vary widely, and the condyle is one of the least frequent places inside the occipital bone. The approach employed provides excellent access to the region, in particular to the atlantooccipital joint. The width and angle of exposition are increased as compared with the traditional suboccipital approach, which facilitates the radical resection of the lesion with no neural retraction and without any surgical complications.

[Parent-child relations within the context of immigration. What we know and we should know]. / Les relations parents-enfants dans un contexte d'immigration. Ce que nous savons et ce que nous devrions savoir.

This article presents an overview of the actual and potential state of knowledge on parent-child relationships within the context of immigration. In addition, it examines the impact of parent-child relationships on the development of the child. The first part gives an update on empirical research carried out in that and an analysis of criticism by specialists in the field. The second half, which focuses on studies originating from disciplines other than child psychology, suggests approaches other than the simple intercultural comparison and underscores the true issue of immigration on family relationships, the complexity of the parental task with regard to immigration, its dynamic properties as well as the adaptation that is required. The author goes on to describe more specifically the role of the cultural and ecological contexts, the double cultural influence to which parents are exposed, the difficulties in relation with the transition and the attitudes of parents during the culture-learning process.

[Therapy for children or therapy of systems ? Analysis of the living conditions of mothers consulting for a child in pedopsychiatry.]. / Thérapie d'enfants ou thérapie de systèmes? Analyse des conditions de vie de mères venues consulter pour un enfant en pédopsychiatrie.

The general objective of this research is to better understand the relationships between material, social and cultural conditions of families, and the mental health of children. In particular, do the experiences faced by mothers have an impact on infant psycho-pathology? This research will therefore trace a profile of the economic, social and cultural characteristics of mothers who were seen in child psychiatry at l'Hôpital Maisonneuve-Rosemont. The results obtained will permit a reflection on our intervention model and a questioning of its pertinence.

[Anglo-Saxon social research in mental health : tendencies, limits and impasses.]. / La recherche sociale anglo-saxonne en santé mentale : tendances, limites et impasses.

In this critical review of English-language research on mental health, the authors identify the dimensions and variables taken into consideration in analyzing, on the one hand, social space and, on the other hand, the field of mental health. Three essential aspects of the body of research are analyzed : theoretical frames of reference ; methods and instruments ; and how links are made between social variables and mental-health problems. In a long conclusion, orientations of French-Quebec social research into mental health are compared to those of English research.

Prognostic implications of tissue oxygen saturation in human septic shock.

PURPOSE: To analyze the prognostic value of tissue oxygen saturation (StO(2)) in septic shock patients with restored mean arterial pressure (MAP). METHODS: This was a prospective observational study of patients admitted to the ICU in the early phase of septic shock, after restoration of MAP. Demographic data, severity score, hemodynamics, blood lactate, acid-base status, and StO(2) were measured at inclusion followed by a transient vascular occlusion test (VOT) to obtain the StO(2)-deoxygenation (DeOx) and StO(2)-reoxygenation (ReOx) rates. Sequential organ failure assessment (SOFA) score was measured at inclusion and after 24 h. RESULTS: Thirty-three patients were studied. StO(2) was 76 ± 10%, DeOx -12.2 ± 4.2%/min, and ReOx 3.02 ± 1.70%/s. MAP showed a significant correlation with VOT-derived slopes (r = -0.4, p = 0.04 for DeOx; and r = 0.55, p < 0.01 for ReOx). After 24 h, 17 patients (52%) had improved SOFA scores. Patients who did not improve their SOFA showed less negative DeOx values at inclusion. The association between DeOx and SOFA evolution was not affected by MAP. Both DeOx and ReOx impairment correlated with longer ICU stay (r = 0.44, p = 0.05; and r = -0.43, p = 0.05, respectively). CONCLUSIONS: In a population of septic shock patients with restored MAP, impaired DeOx was associated with no improvement in organ failures after 24 h. Decrements in DeOx and ReOx were associated with longer ICU stay. DeOx and ReOx were linked to MAP, and thus, their interpretation needs to be made relative to MAP.

[Community-acquired pneumonia: a 7-years descriptive study. Usefulness of the IDSA/ATS 2007 in the assessment of ICU admission]. / Neumonía comunitaria grave. Estudio descriptivo de 7 años y utilidad de los criterios de la Infectious Diseases Society of America y la American Thoracic Society 2007 en la identificación de los pacientes que requieren ingreso en una unidad de cuidados intensivos.

OBJECTIVE: To describe the clinical characteristics and outcomes of patients with community-acquired pneumonia (CAP) admitted to the Intensive Care Unit (ICU). To evaluate new ATS/IDSA criteria to identify patients with CAP who required admission to ICU. DESIGN: Retrospective analysis of prospective collected data in a 7-year period (2000-2007). SETTING: Medical-surgical ICU with 16 beds. PATIENTS: All patients with severe CAP admitted to the ICU (n=147). PRIMARY ENDPOINTS: Clinical and microbiological characteristics. Prognostic factors. Comparison of patients admitted in the ICU and ATS/IDSA criteria (group 1: > or = 1 major criterion, group 2: > or = 3 minor criteria and group 3: no criterion). INTERVENTION: None. RESULTS: Admission to the ICU is required for patients with acute respiratory failure (60.5%) and with septic shock (28.5%). A total of 71.4%, had an identifiable microbial etiology, S. pneumoniae being the most frequently isolated. Mean time to antibiotic therapy was 4.3+/-4.2h, this being adequate in 97.1%. ICU global mortality rate was 32%. Prognostic factors associated with higher mortality were acute renal failure (OR:4.7), mechanical ventilation (OR:3.4), non-identifiable etiology (OR:4.2) and non-S. pneumonia etiology (OR:3.5). Sixty-eight percent of the patients were included in the first group of the ATS/IDSA criteria and 21% in the second group. CONCLUSIONS: CAP mortality is still high despite early antibiotic therapy, especially in those patients with a non-S. pneumonia etiology or who require mechanical ventilation. Almost 90% of the ICU admissions were identified by the new criteria from ATS/IDSA.

[Bacterial bloodstream infections in critical patients]. / Bacteriemia en el paciente crítico.

Bloodstream infection, together with ventilator-associated pneumonia, is the most frequent nosocomial infection in critically ill patients; it is associated with significant morbidity and mortality. As bloodstream infections in critical patients are usually due to intravascular catheters, they can be caused by both gram-positive and gram-negative microorganisms. Furthermore, infection with multiresistant organisms is becoming more common, and this makes the choice of empirical antibiotic treatment more difficult. Patients with severe community-acquired infections account for a large percentage of patients who require admission to intensive care units for hemodynamic instability or organ dysfunction. Many of these also have bacterial bloodstream infections; about 30% of all bacterial bloodstream infections in critical patients occur in this group of patients. Among this group, 70% develop severe sepsis or septic shock, both of which have high mortality. Recently, another classification scheme included a distinct group comprising patients with community-acquired bloodstream infections after recent or intermittent contact with healthcare facilities. When choosing the empirical antibiotic treatment, it is important to bear in mind that this group has specific characteristics that are often comparable to nosocomial infections. We describe the characteristics, origins, causes, and most common complications of nosocomial, community-acquired, and healthcare-related bacterial bloodstream infections in critical patients to make it easier to recognize them early and initiate efficacious empirical antibiotic therapy and thus improve the prognosis of these patients.

Total knee arthroplasty with limitations of flexion.

UNLABELLED: Does total knee arthroplasty (TKA) increase mobility in stiff knees, where flexion is restricted due to degenerative changes associated with osteoarthritis, inflammatory disease, hemophilia, or post-traumatic sequelae also affecting soft tissue? The results of one hundred twenty eight TKA from five specialized centers were retrospectively reviewed. Only knees with pre-operative flexion less than 90 degrees were included. Forty six of these also had severe flexion contracture (>20 degrees). As a result of the arthroplasty, the flexion increased by 23+/-17 degrees in group 1 (stiff flexion only, 82 cases), and by 17+/-15 degrees in group 2 (combined stiffness), in which the total range of motion (ROM) increased by 39+/-21 degrees. Improvements in mobility were greater in the cases with severe pre-operative stiffness. One-year functional results did not correlate with final flexion. Flexion at last follow-up did not depend on pre-operative flexion; however, in group 2, final postoperative ROM did correlate with pre-operative ROM. Complications concerned mainly those cases with severe stiffness, in which extensive quadriceps release was performed (two cases of skin necrosis, one infection and one rupture of the patellar tendon), or the patients of group 2 (one skin necrosis, two femoral fractures, one infection and one sciatic nerve palsy). Hemophilia was a factor of poor prognosis. Overall, TKA provided significant flexion gain. It often required tibial tuberosity osteotomy, to improve exposure and prevent injury to the extensor mechanism. Extensive quadriceps release should be reserved to post-traumatic cases with intact skin and no recent infection. TYPE OF STUDY: level 4 retrospective.

Total knee arthroplasty in patients with greater than 20 degrees flexion contracture.

UNLABELLED: Does total knee arthroplasty (TKA) correct the flexion contracture in knee stiffness associated with osteoarthritis, inflammatory disease, hemophilia or post-traumatic sequelae? The results of 107 TKAs from five specialized centers were retrospectively reviewed. Only knees with greater than or equal to 20 degrees flexion contracture on extension were included, 46 of which also had less than 90 degrees flexion. As a result of the arthroplasty, extension increased by 20+/-6 degrees in group 1 (flexion contracture only, n=61), and by 22+/-11 degrees in group 2 (combined stiffness, n=46), in which the total range of motion increased of 39+/-21 degrees. Overall, mean residual flexion contracture was 7+/-7 degrees. Improvements in mobility were greater in the cases with severe preoperative stiffness. One-year functional results correlated with final residual flexion contracture. Mobility at last follow-up did not depend on preoperative mobility, except in group 2, in which the final postoperative range of motion (ROM) correlated with preoperative ROM. Hemophilia was a factor of poor prognosis. Recovering full extension at end of surgery is mandatory, by first releasing the posterior capsule and the collateral ligaments from their osteophytes, and secondly by extending the distal femoral cut where necessary. TYPE OF STUDY: Level 4 retrospective.