Diagnosing TB infection in children: analysis of discordances using in vitro tests and the tuberculin skin test.

The aim of the present study was to compare the performance of the interferon (IFN)-γ tests (QuantiFERON®-TB Gold In-Tube (QFT-G-IT) and T-SPOT®.TB) with the tuberculin skin test (TST) in diagnosing tuberculosis (TB) infection in children, and to analyse discordant results. This was a prospective study including 98 children from contact-tracing studies and 68 children with TST indurations ≥ 5 mm recruited during public health screenings. Positive IFN-γ tests results were associated with risk of exposure (p<0.0001). T-SPOT.TB was positive in 11 (78.6%) out of 14 cases with active TB and QFT-G-IT in nine (64.3%) out of 14 cases. Sensitised T-cells against Mycobacterium avium were detected in six out of 12 children not vaccinated with bacille Calmette-Guérin (BCG), a TST induration 5-9 mm in diameter and both IFN-γ tests negative. In concordant IFN-γ tests results, a positive correlation was found (p = 0.0001) between the number of responding cells and the amount of IFN-γ released. However, in discordant IFN-γ tests results this correlation was negative (p = 0.371): an increase in the number of spot-forming cells correlated with a decrease in the amount of IFN-γ released. The use of IFN-γ tests is helpful for the diagnosis of TB infection, avoiding cross-reactions with BCG immunisation and nontuberculous mycobacterial infections. The analysis of highly discordant results requires further investigation to elucidate possible clinical implications.

Multicenter study of the multiple organ dysfunction syndrome in intensive care units: the usefulness of Sequential Organ Failure Assessment scores in decision making.

OBJECTIVE: This study examined the incidence and mortality of multiple organ dysfunction syndrome (MODS) in intensive care units, evaluated the limitation of life support in these patients, and determined whether daily measurement of the Sequential Organ Failure Assessment (SOFA) is useful for decision making. DESIGN AND SETTING: Prospective, observational study in 79 intensive care units. PATIENTS AND PARTICIPANTS: Of the 7,615 patients admitted during a 2-month period we found 1,340 patients to have MODS. MEASUREMENTS AND RESULTS: We recorded mortality and length of stay in the intensive care unit and the hospital and the maximum and minimum total SOFA scores during MODS. Limitation of life support in MODS patients was also evaluated. Stepwise logistic regression was used to determine the factors predicting mortality. The in-hospital mortality rate in patients with MODS was 44.6%, and some type of limitation of life support was applied in 70.6% of the patients who died. The predictive model maximizing specificity included the following variables: maximum SOFA score, minimum SOFA score, trend of the SOFA for 5 consecutive days, and age over 60 years. The model diagnostic yield was: specificity 100%, sensitivity 7.2%, positive predictive value 100%, and negative predictive value 57.3%; the area under the receiver operating characteristic curve was 0.807. CONCLUSIONS: This model showed that in our population with MODS those older than 60 years and with SOFA score higher than 9 for at least 5 days were unlikely to survive.

Withdrawing and withholding life support in the intensive care unit: a Spanish prospective multi-centre observational study.

OBJECTIVE: To determine how frequently life support is withheld or withdrawn from adult critically ill patients, and how physicians and patients families agree on the decision regarding the limitation of life support. DESIGN: Prospective multi-centre cohort study. SETTING: Six adult medical-surgical Spanish intensive care units (ICUs). PATIENTS AND PARTICIPANTS: Three thousand four hundred ninety-eight consecutive patients admitted to six ICUs were enrolled. MEASUREMENTS AND RESULTS: Data collected included age, sex, SAPS II score on admission and within 24 h of the decision to limit treatment, length of ICU stay, outcome at ICU discharge, cause and mode of death, time to death after the decision to withhold or withdraw life support, consultation and agreement with patient's family regarding withholding or withdrawal, and the modalities of therapies withdrawn or withheld. Two hundred twenty-six (6.6%) of 3,498 patients had therapy withheld or withdrawn and 221 of them died in the ICU. Age, SAPS II and length of ICU stay were significantly higher in patients dying patients who had therapy withheld or withdrawn than in patients dying despite active treatment. The proposal to withhold or withdraw life support was initiated by physicians in 210 (92.9%) of 226 patients and by the family in the remaining cases. The patient's family was not involved in the decision to withhold or withdraw life support therapy in 64 (28.3%) of 226 cases. Only 21 (9%) patients had expressed their wish to decline life-prolonging therapy prior to ICU admission. CONCLUSIONS: The withholding and withdrawing of treatment was frequent in critically ill patients and was initiated primarily by physicians.

Intrahepatic vascular division in the pig: basis for partial hepatectomies.

Transplantation of resected hepatic fragments, with the attendant vascular and biliary tract reconstruction, presents difficulties. We have studied the intraparenchymal vascular division in the pig with a view to performing partial hepatectomies with the greastest possible anatomical support. Forty-six molds of the various vascular territories were obtained from the 31 porcine livers. Each segment of the median lobe is dependent on the adjacent lateral lobe. Its intersegmental fissure is the obligatory site for parenchymal section to be continued through horizontal portion of portal vein, hepatic artery, and left hepatic duct. A right hemihepatectomy unfailingly results in the devitalization of the left side of the liver. If the goal of a hepatectomy is the transplantation of the resected fragment, it is recommended that the right side of the liver be utilized, as its more convenient extrahepatic vascular and biliary calibre will permit pedicular conservation and anastomosis.

Molecular and conventional epidemiology of tuberculosis in an inner city district.

SETTING: Molecular epidemiology has underlined the importance of recent tuberculosis (TB) transmission and has uncovered notable discrepancies compared with conventional epidemiology. OBJECTIVES: 1) To determine, by RFLP analysis, the percentage of clustered cases in an inner city district with a high incidence of TB (163/100,000) and the groups at risk of being clustered; and 2) to compare the role of conventional contact tracing (CCT) with that of RFLP. DESIGN: RFLP was carried out using the IS6110 and pTBN12 (PGRS) sequences of 165 cultures positive for Mycobacterium tuberculosis in the Ciutat Vella district of Barcelona during 1997-1998. Contact tracing was carried out in 171 of 251 declared cases (68.1%). Associations were assessed by calculating odds ratios (OR) with 95% confidence intervals (CI). Logistic regression was used for multivariate analysis. RESULTS: Using RFLP, 76 (46.0%) strains were found to be clustered by IS6110 and PGRS. From CCT, 30 new patients were found among 858 contacts (3.5%) and 57 patients were linked. In terms of RFLP and CCT, the main risk factor was intravenous drug use (IVDU). In 44 cases who lived alone and were not involved in CCT, 50% were in RFLP clusters. The concordance rate between RFLP and CCT was 8/13 (61.5%); the disagreement corresponded to a cluster of five recent immigrants from Africa. Subsequent to RFLP, an epidemiological connection was found in 15/55 cases (27.2%). CONCLUSIONS: The percentage of clustered cases is very high. CCT was useful for identifying new cases, but it was insufficient for detecting the pathways of transmission. CCT coverage needs to be improved in marginalized individuals, and the results correlated with those of RFLP.

Estimation of kinetic rates in batch Thiobacillus ferrooxidans cultures.

In this work, the key problem of estimation in bioprocesses when no structural model is available is dealt with. A nonlinear observer-based algorithm is developed in order to estimate kinetic rates in batch bioreactors. The algorithm uses the measurements of biomass concentration and either substrate concentration or redox potential to perform the estimation of the respective specific kinetic rates. For this purpose, a general mathematical model description of the process is provided. The estimation algorithm design is based on a nonlinear reduced-order observer. The observer performance is validated with experimental results on a Thiobacillus ferrooxidans batch culture.

[Fibrinolytic treatment in acute myocardial infarction: analysis of delay]. / Tratamiento fibrinolítico en el infarto agudo de miocardio: análisis de los tiempos de demora.

BACKGROUND: The delay time from the onset of symptoms to the initiation of intravenous fibrinolytic treatment in patients with acute myocardial infarction (AMI) is herein described. METHODS: A study was carried out of the consecutive AMI diagnosed in the Medical Area of the Emergency Department of the Hospital del Mar in Barcelona, Spain, with a 24-hour follow up from 15 May 1993 to 14 January, 1994. All the patients under the age of 80 years with transmural AMI of any localization and evolution of under 6 hours were considered to receive fibrinolytic treatment. The following delay times were analyzed: total delay time, extrahospitalary delay time and intrahospitalary delay time, which included assistance delay time, delay in fibrinolytic treatment indication and delay time in performance of the same. RESULTS: During the study period 18,316 patients were attended in the Emergency Medical Area, of which 80 corresponded to AMI. Fibrinolytic treatment was initiated with intravenous streptokinase in 33 patients (41.3%). The total delay time was 287.2 +/- 202.6 (mean +/- SD) minutes; the extrahospitalary and intrahospitalary delays were 159.8 +/- 151.7 and 126.8 +/- 161.7 minutes, respectively. The delay time for assistance was 8.5 +/- 12.7 minutes, the delay time in treatment indication was 78.8 +/- 101.8 minutes and in performance it was 39.5 +/- 52.6 minutes. This latter time was analyzed on the basis of the administration site, with statistically significant differences (p < 0.005) if the fibrinolytic treatment was performed in the Emergency Medical Area (12.5 +/- 0.7 minutes), in the observation room (41.4 +/- 50.7 minutes) or in the Intensive Care Unit (61.4 +/- 75.8 minutes). CONCLUSIONS: Most of the intrahospitalary delay in the administration of fibrinolytic treatment is due to decision delay in regards to carrying out this therapy.

Monitoring changes in anti-tuberculosis treatment: associated factors determined at the time of diagnosis.

OBJECTIVES: To determine predictive factors for changes in standard anti-tuberculosis chemotherapy at the time of diagnosis. METHODS: A prospective study was performed among tuberculosis (TB) patients treated at specialised centres during 2008-2009. Treatment outcome was monitored per standard guidelines. Treatment was considered successful if the patient was cured or completed treatment. Factors associated with treatment modification were analysed at the bivariate and multivariate levels using logistic regression. RESULTS: A total of 427 patients were included in the study. The initial standard treatment regimen was retained for 249 patients (58.3%), extended to 9 months for 36 (8.4%) and changed for 142 (33.3%). Factors associated with a change of regimen at the multivariate level were female sex, age ≥ 50 years, human immunodeficiency virus infection, comorbidities, alcoholism, hospitalisation and culture-positive sputum. Drug resistance and toxicity were analysed independently. Treatment outcome was successful in 97.2% of cases without a regimen change and in 87.3% of those with a changed regimen (P < 0.001). CONCLUSION: Factors associated with changes in the initial anti-tuberculosis regimen should be considered for rigorous follow-up. Results obtained through individualised treatment provided by specialists were good despite the complexity of the cases treated.

[Allocation of resources in patients with bad prognosis: the need for debate]. / La adjudicación de recursos en los pacientes con mal pronóstico: la necesidad de un debate.

OBJECTIVE: Assess the opinion of health care professions on the awarding of resources when the patient has a bad prognosis. DESIGN: Survey type test where a scenario of a patient with a 6 month life prognosis is posed, differentiating between good and bad quality of life. It is evaluated if the following resources would be indicated if necessary: admission to ICU, hemodialysis, hip prosthesis, transplant, Hospital admission, antibiotics for bacterial infection, permanent pacemaker and surgery. To analyze the possible association between the variables, the Pearson's Chi Square Test or that of linear tendency was used. To determine if each person interviewed was appropriate in a different way based on the patient's quality of life status, the McNemar test was used. SETTING: University Hospital of 480 beds. PARTICIPANTS: Sample of 256 volunteers (physicians and nurses) from the Emergency Service, Intensive Care Unit and Operating Room. INTERVENTIONS: A responsible physician was in charge of personally distributing the survey during a 2-week period and to explain the possible doubts that could arise on it. RESULTS: A total of 23.8% of those surveyed considered that transplant would be indicated and 79.8% that permanent pacemaker would be indicated if the patient had a good quality of life. If there was bad quality of life, 9.1% would have always indicated hemodialysis (60.5% never), 2.8% hip prosthesis (81.1% never) and 4% complex surgery (78.8% never). There were also significant differences in all the variables studied, depending on whether the patient had good or bad quality of life. CONCLUSION: There is great variability on the allotment of resources for patients with limited possibilities of survival.

Are auditory warnings in the intensive care unit properly adjusted?

The purpose of this study was to determine whether auditory warnings in the intensive care unit (ICU) were properly adjusted. An intervention study (before- and-after assessment) was conducted in a 12-bed medical-surgical ICU of an acute-care teaching hospital in Barcelona, Spain. A total of 100 patients with stable haemodynamic and respiratory parameters were included. In the first 3-month phase of the study, minimum and maximum alarm parameters of breathing rate, expired volume/min, airway pressure, SaO(2), arterial blood pressure and heart rate were recorded. In the second 12-month phase of the study, the same alarm parameters were recorded every 4 hours in the patient's medical record. In the third 3-month phase of the study, alarm readings were recorded again as in the first phase. The change throughout coefficient of variation (CV) and the 95% confidence interval (CI) for each alarm were calculated. Following the intervention, there was a statistically significant improvement in alarm readings for expired volume, heart rate and systolic blood pressure, so that alarms had been more properly adjusted to the patient's real value. Nursing staff should be aware that auditory warnings in ICU stable patients are frequently set very far from suitable values. Recording of alarm parameters in the patient's medical record as a routine daily activity was an effective intervention for improving adjustment of auditory warnings.

Diagnostic efficacy of the study of contacts of tuberculosis patients in a high prevalence urban area. / Eficacia diagnóstica del estudio de contactos de enfermos tuberculosos en un distrito urbano de alta prevalencia.

BACKGROUND: The investigation of contacts (CI) is a main objective for the control of tuberculosis (TB) after therapeutic compliance. The present study was planned to determine the diagnostic effectiveness and degree of CI implementation as well as risk factors to generate new cases in a high prevalence area (163/10(5)). PATIENTS AND METHODS: An analysis was made of the available data of CI in the Barcelona district of Ciutat Vella in 1997 and 1998. The odds ratio (OR) was calculated as a measure of the association with infection and tuberculosis disease with a 95% confidence interval (CI) by logistic regression. RESULTS: CI was made in 65.2% of patients and 100% of tuberculin-positive children. Thirty patients were diagnosed among 858 contacts of 135 tuberculosis patients (3.49%) and 8 among 318 contacts of 64 primoinfected children aged less than 15 years (2.51%). Prevalence of tuberculosis infection was 51.51% and 46.85%, respectively. The characteristics of the index case associated with new patients were drug abuse (OR: 11.16; CI: 3.0-40.9) and to be prisoner (OR: 18.7; CI: 1.5-232.9). No influence was detected regarding sputum acid-fast smears and degree of closeness except for contacts aged less than 20 years. CONCLUSIONS: CI is cost-effective in this area of high prevalence and should be performed in every TB case although priority groups are prisoners and/or drug abusers and contacts aged less than 20 years. The implementation of CI can be improved in our setting.

[Variability in working systems in intensive care units]. / La variabilidad en las sistemáticas de trabajo en los Servicios de Medicina Intensiva.

INTRODUCTION: Patients attended in Intensive Medicine Services (IMS) require a high therapeutic support. To do so, each IMS elaborates a work system (monitoring of constants, insertion of catheters,...) aiming to respond to these high necessities of therapy. The objective of this study is to describe the variability among different IMS. METHODS: The study was performed in 15 hospitals in Catalonia between April and May 1995. In the end two of them did not participate in the study. In each hospital 180 pieces of data were collected referring to their material and human resources, graphics of data collection, monitoring of respiratory system (mechanical ventilator, aspirations of secretions, tracheostomy care), techniques of catheterization of artery and venous via vesical probing, prevention of pressure ulcers , hygiene of patients, nutrition, family treatment and data about medical orders and nursing courses. Similarly, the fact whether the work system was justified by studies from the same IMS, other centres, or whether it was simply unknown, was also evaluated. RESULTS: There was a great variability among the IMS studied, oscillating significatively according to assigned resources, frequency of action and cost. According to the procedure 61% of IMS did not justify the work systems depending on scientific data. CONCLUSION: it is necessary to unify the different work systems. To do so, and in our opinion, scientific societies should establish common norms, guidelines and protocols so as to obtain a higher efficiency of IMS.

Changes in circulating glycerol, free fatty acids and glucose levels following liver transplant in the pig.

Female pigs, fasted overnight, received an orthotopic liver transplant. During the nonhepatic phase, both blood glycerol and plasma free fatty acid concentrations increased, returning to basal values after the transplant, indicating that the liver is the main receptor of these products released in the blood from the glyceride breakdown in peripheral fat deposits. Blood glucose level rose during the nonhepatic phase, probably due in part to the perfusion of glucosated saline received by the animals during this phase. After liver transplant, blood glucose levels progressively decreased and this effect was greatly reduced by administering L-alanine. Our data indicate that metabolic changes in the donor's liver diminish the availability of gluconeogenetic substrates immediately following transplant, while administration of exogenous alanine permits faster restoration of gluconeogenetic function in the transplanted liver.