[Predictors of weaning and mortality in prolonged mechanical ventilation ­ surviving survival]. / Predictores de desvinculación y mortalidad en ventilación mecánica prolongada-Sobrevivir al sobrevivir.

Objetive: to describe a sample of tracheostomized patients requiring prolonged mechanical ventilation who were admitted to a weaning center, to analyze their evolution and to determine the predictors of weaning failure from mechanical ventilation and of mortality. Design: Design: an observational and retrospective cohort study was carried out, in the period between January 2005 and December 2017. Setting: weaning and rehabilitation center. Patients: all tracheostomized patients requiring mechanical ventilation who were admitted during the study period were included. Of 1027 patients admitted to the respiratory care service, a consecutive sample of 677 patients was analyzed. Main variables of interest: the main variables were mortality and weaning failure from mechanical ventilation. Results: : age older than 70 years (OR 1,461 95% CI 1,016-2,099), a cardiovascular history (OR 1,533 95% CI 1,050-2,237), admission due to respiratory disease (OR 1,538 95% CI 1,001-2,364) and presenting more than 105 days of hospitalization (OR 0,408 95% CI 0,261-0,637) were found as predictors of weaning failure. The predictors of mortality were, age over 70 years (OR 2,116 95% CI 1,491-3,004), history of cerebrovascular accident (OR 1,991 95% CI 1,255-3,158), admission to intensive care due to cardiorespiratory arrest (OR 5,821 95% CI 2,193-15,445) and presenting more than 64 days of hospitalization (OR 1, 63 95% CI 1,116-2,292). Conclusions: The data found in this study manage to describe factors associated with weaning and mortality of patients in a weaning and rehabilitation center.

Objetivos: describir una muestra de pacientes traqueostomizados con requerimiento de ventilación mecánica prolongada que ingresaron a un centro de desvinculación, analizar su evolución y determinar los predictores de fracaso de desvinculación de la ventilación mecánica y de mortalidad. Diseño: se realizó un estudio de cohorte observacional y retrospectivo, en el período comprendido entre enero del 2005 y diciembre del 2017. Ámbito: centro de desvinculación de la ventilación mecánica y de rehabilitación. Pacientes: se incluyeron a todos los pacientes traqueostomizados con requerimiento de ventilación mecánica, que ingresaron durante el periodo de estudio. De 1027 pacientes ingresados al servicio de cuidados respiratorios, se analizó una muestra consecutiva de 677 pacientes. Variables de interés principales: las variables principales fueron mortalidad y falla en la desvinculación de la ventilación mecánica. Resultados: Se encontraron como predictores del fracaso de la desvinculación la edad mayor a 70 años (OR 1.461 IC95% 1.016-2.099), tener antecedentes cardiovasculares (OR 1.533 IC95% 1.050-2.237), motivo de ingreso por afección respiratoria (OR 1.538 IC95% 1.001-2.364) y presentar más de 105 días de internación (OR 0.408 IC95% 0.261-0.637). Los predictores de mortalidad fueron, la edad mayor a 70 años (OR 2.116 IC95% 1.491-3.004), tener como antecedente un accidente cerebro-vascular (OR 1.991 IC95% 1.255-3.158), motivo de ingreso a terapia intensiva por paro cardiorrespiratorio (OR 5.821 IC95% 2.193-15.445) y presentar más de 64 días de internación (OR1.63 IC95% 1.116-2.292). Conclusión: Los datos hallados en este estudio logran describir factores asociados a la desvinculación y mortalidad de los pacientes en un centro de desvinculación.

Prevalence of and Risk Factors for Mechanical Ventilation Reinstitution in Patients Weaned From Prolonged Mechanical Ventilation.

BACKGROUND: Prolonged mechanical ventilation is increasingly common in ICUs. Although a consensus conference defined weaning success in this patient population, few studies have used this definition. A clear definition of successful weaning is useful to assess clinical and epidemiological outcomes, facilitate clinical decision making, and set goals of care. The aims of our study were to describe the prevalence of reinstitution of mechanical ventilation within 28 d in patients successfully weaned according to our institution criterion (ie, weaning success as per consensus guidelines), to describe reasons to reestablish mechanical ventilation, and to identify associated factors. METHODS: An observational, analytical, cross-sectional study was conducted at a weaning and rehabilitation center. All patients liberated from mechanical ventilation (ie, no ventilatory support for 7 d) were included as subjects. Requirement of and reasons for reinstitution of mechanical ventilation within 28 d of weaning were recorded. RESULTS: A total of 639 tracheostomized subjects were analyzed. Of these, 219 (34%) were weaned, and 15 were eliminated due to lack of data. Of the remaining 204 subjects, 42 (21%) were reconnected to mechanical ventilation within 28 d. Sepsis accounted for 64% of reconnections. In the multivariate analysis, neurological comorbidity (adjusted odds ratio 5.1 [95% CI 2.3-11.1]) and delayed weaning (> 7 d after admission) (adjusted odds ratio 2.37 [95% CI 1.1-5.3]) were independently associated with reinstitution of mechanical ventilation within 28 d of weaning. The synergistic effect of both variables showed an adjusted odds ratio of 5.35 (95% CI 2.4-11.4). CONCLUSIONS: Reinstitution of mechanical ventilation within 28 d is a common event in patients considered to be weaned: 1 in 5 of such patients requires reconnection to mechanical ventilation, with sepsis being the most prevalent cause. Neurological comorbidity and delayed weaning are risk factors associated with reestablishment of mechanical ventilation. The presence of more than one risk factor increases the association with reinstitution of mechanical ventilation within 28 d of weaning.

Prevalence and Characteristics of Tracheal Lesions Observed in Tracheostomized Patients.

BACKGROUND: Our objective was to describe the prevalence and characteristics of tracheal lesions observed in flexile bronchoscopies of tracheostomized patients, and to determine those factors associated with severe injuries. METHODS: This is an analytical, observational, and transversal study. The flexible bronchoscopies of tracheostomized patients from our database were reviewed to assess their lesions. The tracheal lesions were classified according to their severity; lesions obstructing above 50% of the lumen were interpreted as severe and those obstructing <50% as mild. The lesions were also classified according to location as glottic, subglottic, at the level of the tracheal ostomy, tracheal, and bronchial. The types of lesions found were granuloma, stenosis, and excessive central airway collapse. Possible predictors of severe lesions were assessed. RESULTS: A total of 414 patients were included in the study, the mean age being 65 years (±16.2 y). Of all the bronchoscopies assessed, 202 (49%) showed mild lesions, and 91 (22%) were severe. We found granulomas in 230 patients (55%), and 32 (26%) were severe. Of the 27 patients with stenosis (7%), 17 (63%) were severe. Excessive central airway collapse was seen in 120 patients (31.8%), and 65 (54%) were severe. There were statistically significant differences related to age in the group that developed severe lesions (mean age, 73 y; Q1 to Q3, 58 to 81) compared with the group free of lesions (mean age, 69 y; Q1 to Q3, 55.7 to 75; P = 0.001) and also in the duration requiring an artificial airway (mean, 84.5 d; Q1 to Q3, 49 to 135.5) compared with the group free of lesions (mean of 59.5 d; Q1 to Q3, 42 to 98; P = 0.035). CONCLUSION: There was a high prevalence of tracheal lesions, mainly subglottic granulomas. Age and the duration for which the patient required an artificial airway were related to the presence of severe lesions.

Incidencia de infecciones respiratorias en pacientes traqueostomizados en un centro de desvinculación de la ventilación mecánica y rehabilitación / Incidence of respiratory tract infections in tracheostomized patients hospitalized in a weaning and rehabilitation center

Objetivos: Describir la incidencia de infecciones respiratorias (IR) en pacientes traqueostomizados (TQT) internados en un centro de desvinculación de la ventilación mecánica y rehabilitación (CDVMR). Identificar factores de riesgo (FR) para el desarrollo de IR. Materiales y métodos: Se realizó un estudio de casos y controles anidado en una cohorte. La variable utilizada para el apareamiento fue la edad. Se incluyeron a todos los pacientes TQT internados durante el período de marzo del 2013 a febrero del 2015. Se registró la incidencia de IR. Resultado: Se incluyeron 167 pacientes, registrándose 73 eventos de IR en 46 pacientes. La incidencia acumulada fue de 27,5% y la tasa de incidencia fue de 2,22 eventos/1000 días de estadía. De los 73 eventos registrados, se obtuvieron rescates bacteriológicos en 50 de ellos, siendo Pseudomonas aeruginosa (34,3%) el microorganismo más prevalente. Los valores más bajos de albúmina resultaron ser un FR para el desarrollo de IR (p 0.001, OR 5.82, IC 2.08-16.2). Los valores más altos de hemoglobina de ingreso se comportaron como factor protector (p 0.048, OR 0.74, IC 0.55-0.99). Se establecieron como FR para el evento IR: ingresar con diagnóstico de ACV (p 0.025, OR 3.45 1.16-10.2), Parkinson (p 0.011, OR 18.9, IC 1.93-185) o ELA (p 0.013, OR 6.34, IC 1.47-27.2). Conclusión: Se logró determinar por primera vez en nuestro medio la incidencia de IR en pacientes TQT y los patógenos más comunes, aunque esto necesita contraste con otros CDVMR. La asociación encontrada entre los valores de albúmina y el posterior desarrollo de IR podría estar relacionada más a un sesgo probabilístico que a una diferencia clínica significativa. Los pacientes con determinadas enfermedades neurológicas presentan mayor riesgo de IR.

Incidence of respiratory tract infections in tracheostomized patients hospitalized in a weaning and rehabilitation center

Objectives: To describe the incidence of respiratory tract infections (RTIs) in tracheostomized patients hospitalized in a weaning and rehabilitation center (WRC) and to identify risk factors (RFs) for the development of RTI. Materials and methods: A nested case-control study was conducted. Age was used as the matching variable. All tracheostomized patients who were hospitalized from March, 2013, to February, 2015, were included. The incidence of RTI was recorded. Results: A total of 167 patients were included, with 73 RTI episodes being recorded in 46 patients (27.5%). Cumulative incidence was 27.5%, and incidence rate was 2.22 episodes per 1,000 days of stay. Bacteria were recovered in 50 of the 73 episodes recorded, with Pseudomonas aeruginosa being the most prevalent organism (34.3%). The lowest albumin values proved to be a RF for the development of RTI (p 0.001, odds ratio [OR] 5.82, confidence interval [CI] 2.08-16.2). The highest hemoglobin values on admission acted as protective factors (p 0.048, OR 0.74, CI 0.55-0.99). Diagnoses of stroke (p 0.025, OR 3.45, CI 1.16-10.2), Parkinson (p 0.011, OR 18.9, CI 1.93-185) or amyotrophic lateral sclerosis (ALS) (p 0.013, OR 6.34, IC 1.47-27.2) on admission were established as risk factors for the development of RTI. Conclusion: For the first time in our setting, it was possible to determine the incidence of RTI in tracheostomized patients and the most common pathogens, although comparison with other WRCs is needed. The association found between albumin values and the subsequent development of RTI might be more related to an incidental finding than to a significant clinical difference. Patients with certain neurologic diseases are at increased risk for RTI.

Effect of tracheostomy tube on work of breathing: Comparison of pre- and post-decannulation.

OBJECTIVE: To describe and compare the work of breathing (WOB) during spontaneous breathing under four conditions: (1) breathing through a tracheostomy tube with an inflated cuff, (2) breathing through the upper airway (UA) with a deflated cuff and occluded tube, (3) breathing through the UA with an occluded cuffless tube, and (4) postdecannulation. PATIENTS AND METHODS: Patients who tolerated an occluded cuffless tube were included. Ventilatory variables and esophageal pressure were recorded. The pressure-time product (PTP), PTP/min, and PTP/min/tidal volume (PTP/min/VT) were measured. Each condition was measured for 5 min with a 15 min time interval between evaluations. Quantitative data are expressed as mean ± standard deviation. Single-factor analysis of variance was used, and the Games-Howell test was used for post hoc analysis of comparisons between group means (P ≤ 0.05). RESULTS: Eight patients were studied under each of the four conditions described above. Statistically significant differences were found for PTP, PTP/min, and PTP/min/VT. In the post hoc analysis for PTP, significant differences among all conditions were found. For PTP/min, there was no significant difference between Conditions 2 and 4 (P = 0.138), and for PTP/min/VT, there was no significant difference between Conditions 1 and 2 (P = 0.072) or between Conditions 2 and 3 (P = 0.106). A trend toward a higher PTP, PTP/min, and PTP/min/VT was observed when breathing through a cuffless tracheostomy tube. CONCLUSION: The four conditions differed with respect to WOB. Cuff inflation could result in a reduced WOB because there is less dead space. Cuffless tracheostomy tubes generate increased WOB, perhaps due to the material deformity caused by body temperature.

Evaluation of an active humidification system for inspired gas.

OBJECTIVES: The effectiveness of the active humidification systems (AHS) in patients already weaned from mechanical ventilation and with an artificial airway has not been very well described. The objective of this study was to evaluate the performance of an AHS in chronically tracheostomized and spontaneously breathing patients. METHODS: Measurements were quantified at three levels of temperature (T°) of the AHS: level I, low; level II, middle; and level III, high and at different flow levels (20 to 60 L/minute). Statistical analysis of repeated measurements was performed using analysis of variance and significance was set at a P<0.05. RESULTS: While the lowest temperature setting (level I) did not condition gas to the minimum recommended values for any of the flows that were used, the medium temperature setting (level II) only conditioned gas with flows of 20 and 30 L/minute. Finally, at the highest temperature setting (level III), every flow reached the minimum absolute humidity (AH) recommended of 30 mg/L. CONCLUSION: According to our results, to obtain appropiate relative humidity, AH and T° of gas one should have a device that maintains water T° at least at 53℃ for flows between 20 and 30 L/m, or at T° of 61℃ at any flow rate.

Factores de riesgo para el fracaso de destete en una población de pacientes con EPOC en ventilación mecánica prolongada / Risk Factors for Weaning Failure in Patients with Chronic Obstructive Pulmonary Disease in Prolonged Mechanical Ventilation

Introducción: Los pacientes con EPOC experimentan episodios de falla respiratoria que requieren de asistencia ventilatoria mecánica (AVM). Debido al compromiso pulmonar, muscular y nutricional, experimentan dificultad en el destete. Hay escasa información de los factores que puedan predecir el fracaso del destete en pacientes con EPOC en VM prolongada (VMP). El objetivo de este trabajo es encontrar factores de riesgo para el fracaso del destete en pacientes con EPOC y evaluar mortalidad según éxito o fracaso en el destete. Materiales y Métodos: El estudio se realizó en un centro de weaning (CW) y se incluyeron pacientes internados en una unidad de terapia intensiva (UTI) por reagudización de su EPOC derivados a nuestro CW traqueostomizados con requerimiento de AVM. Resultados: Se recolectaron los datos de 40 pacientes, de los cuales 21 finalizaron AVM de manera exitosa y 19 fracasaron. El análisis univariado arrojó 4 variables asociadas al fracaso del destete: Pimax (p = 0.035), días de AVM en el CW (p = 0.005), pH (p = 0.039) y la PaCO2 (p = 0.002). Sin embargo, solo la PaCO2 a las 12hs de la prueba de respiración espontánea (PRE) fue predictor de fracaso de destete (p = 0.007). No se encontraron predictores de mortalidad. Conclusión: Encontrar factores de riesgo que permitan identificar el fracaso en la desvinculación de la VM puede contribuir en la decisión de insistir con el destete, o bien, plantear un programa de internación domiciliaria con la finalidad de mejorar la calidad de vida. La única variable asociada al fracaso de destete fue la PaCO2 a las 12hs de comenzada la PRE.

Introduction: Patients suffering from chronic obstructive pulmonary disease (COPD) have an airflow limitation and require mechanical ventilation (MV). Because of deteriorated lung function, respiratory muscles weakness and malnutrition, patients also present difficulties in the weaning process. Information on the factors that can predict weaning failure in patients with COPD after prolonged MV is scarce. To identify risk factors for weaning failure in patients with COPD and evaluate the mortality depending on weaning success or failure. Materials and Methods: This study was carried out at a weaning center in Buenos Aires, Argentina. We evaluated patients admitted to an intensive care unit (ICU) and referred to the weaning center as a result of COPD exacerbation, after tracheostomy and in need of mechanical ventilation. Results: Data from 40 patients were collected; 21 were successfully weaned from MV and 19 failed the weaning process. Univariate analysis showed 4 variables associated with weaning failure: maximum inspiratory pressure (MIP) (p = 0.035), length of MV at weaning center (p = 0.005), pH (p = 0.039) and PaCO2 (p = 0.002). However, only PaCO2 twelve hours after the spontaneous breathing trial (SBT) was a predictor of weaning failure (p=0.007). Mortality predictors were not found. Conclusion: The only predictive variable associated with weaning failure was PaCO2 twelve hours after SBT. Finding risk factors for failure in discontinuing MV may provide information to decide whether to insist in the weaning process or choose home MV to improve life quality.

Factores de riesgo para el fracaso de destete en una población de pacientes con EPOC en ventilación mecánica prolongada

Introducción: Los pacientes con EPOC experimentan episodios de falla respiratoria que requieren de asistencia ventilatoria mecánica (AVM). Debido al compromiso pulmonar, muscular y nutricional, experimentan dificultad en el destete. Hay escasa información de los factores que puedan predecir el fracaso del destete en pacientes con EPOC en VM prolongada (VMP). El objetivo de este trabajo es encontrar factores de riesgo para el fracaso del destete en pacientes con EPOC y evaluar mortalidad según éxito o fracaso en el destete. Materiales y Métodos: El estudio se realizó en un centro de weaning (CW) y se incluyeron pacientes internados en una unidad de terapia intensiva (UTI) por reagudización de su EPOC derivados a nuestro CW traqueostomizados con requerimiento de AVM. Resultados: Se recolectaron los datos de 40 pacientes, de los cuales 21 finalizaron AVM de manera exitosa y 19 fracasaron. El análisis univariado arrojó 4 variables asociadas al fracaso del destete: Pimax (p = 0.035), días de AVM en el CW (p = 0.005), pH (p = 0.039) y la PaCO2 (p = 0.002). Sin embargo, solo la PaCO2 a las 12hs de la prueba de respiración espontánea (PRE) fue predictor de fracaso de destete (p = 0.007). No se encontraron predictores de mortalidad. Conclusión: Encontrar factores de riesgo que permitan identificar el fracaso en la desvinculación de la VM puede contribuir en la decisión de insistir con el destete, o bien, plantear un programa de internación domiciliaria con la finalidad de mejorar la calidad de vida. La única variable asociada al fracaso de destete fue la PaCO2 a las 12hs de comenzada la PRE.(AU)

Introduction: Patients suffering from chronic obstructive pulmonary disease (COPD) have an airflow limitation and require mechanical ventilation (MV). Because of deteriorated lung function, respiratory muscles weakness and malnutrition, patients also present difficulties in the weaning process. Information on the factors that can predict weaning failure in patients with COPD after prolonged MV is scarce. To identify risk factors for weaning failure in patients with COPD and evaluate the mortality depending on weaning success or failure. Materials and Methods: This study was carried out at a weaning center in Buenos Aires, Argentina. We evaluated patients admitted to an intensive care unit (ICU) and referred to the weaning center as a result of COPD exacerbation, after tracheostomy and in need of mechanical ventilation. Results: Data from 40 patients were collected; 21 were successfully weaned from MV and 19 failed the weaning process. Univariate analysis showed 4 variables associated with weaning failure: maximum inspiratory pressure (MIP) (p = 0.035), length of MV at weaning center (p = 0.005), pH (p = 0.039) and PaCO2 (p = 0.002). However, only PaCO2 twelve hours after the spontaneous breathing trial (SBT) was a predictor of weaning failure (p=0.007). Mortality predictors were not found. Conclusion: The only predictive variable associated with weaning failure was PaCO2 twelve hours after SBT. Finding risk factors for failure in discontinuing MV may provide information to decide whether to insist in the weaning process or choose home MV to improve life quality.(AU)

Decanulación después de la estadía en UCI: Análisis de 181 pacientes traqueotomizados / Decannulation after the ICU Stay. Analysis of 181 Tracheostomized Patients

Objetivo: Encontrar predictores de decanulación en pacientes traqueostomizados y desvinculados de la asistencia ventilatoria mecánica. Analizar la mortalidad en el centro de weaning y supervivencia al alta. Materiales y métodos: Estudio retrospectivo. Se revisaron historias clínicas de pacientes que ingresaron al centro de weaning entre enero de 2004 y junio de 2011. Se estudiaron diferentes variables como posibles predictores de decanulación. Se analizó la mortalidad y se realizó seguimiento al alta. Resultados: Se incluyeron 181 pacientes con una media de 62 años. Se logró decanular al 44.2% de los pacientes (mediana 20 días). El análisis univariado encontró 6 variables asociadas al fracaso de decanulación: sexo masculino, antecedentes respiratorios, antecedentes cardiovasculares, albúmina al ingreso al centro de weaning, días de internación en centro de weaning y días de internación en Unidad de Cuidados Intensivos + centro de weaning. La regresión logística encontró como predictores independientes: sexo masculino y antecedentes respiratorios. En el análisis de regresión logística la decanulación fue un factor protectivo con respecto a la mortalidad. El 80% de los pacientes decanulados y el 15,8% de los no decanulados obtuvieron alta médica. La mediana de supervivencia de los decanulados fue de 45.47 meses y los no decanulados de 10.87. Conclusiones: Los pacientes de sexo masculino y aquellos con antecedentes respiratorios se asocian con fracaso de decanulación. Los pacientes decanulados tienen menor riesgo de muerte durante la internación.

Objective: Find predictors of decannulation in tracheostomized patients and without mechanical ventilation. A secondary objective was the analysis of mortality in the weaning center and survival at discharge. Material and methods: We reviewed, retrospectively, the medical records of patients admitted to the weaning center with tracheostomy and without mechanical ventilation between January 2004 and June 2011. Different variables as possible predictors of decannulation were studied. Mortality at weaning center and outcomes during follow up after discharge were analyzed. Results: We included 181 patients with an average age of 62 years old. Decannulation was carried out in 44.2% of the patients. The decannulation process took 20 days. The univariate analysis found six variables associated with decannulation failure: male gender, respiratory or cardiovascular history, albumin at admission to the weaning center, days of hospitalization in the weaning center and admission to intensive care units plus the weaning center. Logistic regression analysis found that male sex and respiratory history were independent predictors. Regarding mortality during hospitalization, logistic regression analysis found that decannulation was a protective factor. Another finding was that 80% of patients decannulated were discharged; only 15.8% of the group was not decannulated. The average survival was 45.47 months among the decannulated patients and 10.87 months for the non decannulated patients. Conclusions: We found that male sex and a history of respiratory failure were factors associated with unsuccessful decannulation. Decannulated patients had lower risk of death during hospitalization.

Decanulación después de la estadía en UCI: Análisis de 181 pacientes traqueotomizados

Objetivo: Encontrar predictores de decanulación en pacientes traqueostomizados y desvinculados de la asistencia ventilatoria mecánica. Analizar la mortalidad en el centro de weaning y supervivencia al alta. Materiales y métodos: Estudio retrospectivo. Se revisaron historias clínicas de pacientes que ingresaron al centro de weaning entre enero de 2004 y junio de 2011. Se estudiaron diferentes variables como posibles predictores de decanulación. Se analizó la mortalidad y se realizó seguimiento al alta. Resultados: Se incluyeron 181 pacientes con una media de 62 años. Se logró decanular al 44.2% de los pacientes (mediana 20 días). El análisis univariado encontró 6 variables asociadas al fracaso de decanulación: sexo masculino, antecedentes respiratorios, antecedentes cardiovasculares, albúmina al ingreso al centro de weaning, días de internación en centro de weaning y días de internación en Unidad de Cuidados Intensivos + centro de weaning. La regresión logística encontró como predictores independientes: sexo masculino y antecedentes respiratorios. En el análisis de regresión logística la decanulación fue un factor protectivo con respecto a la mortalidad. El 80% de los pacientes decanulados y el 15,8% de los no decanulados obtuvieron alta médica. La mediana de supervivencia de los decanulados fue de 45.47 meses y los no decanulados de 10.87. Conclusiones: Los pacientes de sexo masculino y aquellos con antecedentes respiratorios se asocian con fracaso de decanulación. Los pacientes decanulados tienen menor riesgo de muerte durante la internación.(AU)

Objective: Find predictors of decannulation in tracheostomized patients and without mechanical ventilation. A secondary objective was the analysis of mortality in the weaning center and survival at discharge. Material and methods: We reviewed, retrospectively, the medical records of patients admitted to the weaning center with tracheostomy and without mechanical ventilation between January 2004 and June 2011. Different variables as possible predictors of decannulation were studied. Mortality at weaning center and outcomes during follow up after discharge were analyzed. Results: We included 181 patients with an average age of 62 years old. Decannulation was carried out in 44.2% of the patients. The decannulation process took 20 days. The univariate analysis found six variables associated with decannulation failure: male gender, respiratory or cardiovascular history, albumin at admission to the weaning center, days of hospitalization in the weaning center and admission to intensive care units plus the weaning center. Logistic regression analysis found that male sex and respiratory history were independent predictors. Regarding mortality during hospitalization, logistic regression analysis found that decannulation was a protective factor. Another finding was that 80% of patients decannulated were discharged; only 15.8% of the group was not decannulated. The average survival was 45.47 months among the decannulated patients and 10.87 months for the non decannulated patients. Conclusions: We found that male sex and a history of respiratory failure were factors associated with unsuccessful decannulation. Decannulated patients had lower risk of death during hospitalization.(AU)

Evaluation of tracheal cuff pressure variation in spontaneously breathing patients.

BACKGROUND: Most of the studies referring cuff tubes' issues were conducted on intubated patients. Not much is known about the cuff pressure performance in chronically tracheostomized patients disconnected from mechanical ventilation. OBJECTIVE: To evaluate cuff pressure (CP) variation in tracheostomized, spontaneously breathing patients in a weaning rehabilitation center. MATERIALS AND METHODS: Experimental setup to test instruments in vitro, in which the gauge (TRACOE) performance at different pressure levels was evaluated in six tracheostomy tubes, and a clinical setupin which CP variation over 24 h, every 4 h, and for 6 days was measured in 35 chronically tracheostomized clinically stable, patients who had been disconnected from mechanical ventilation for at least 72 h. The following data were recorded: Tube brand, type, and size; date of the tube placed; the patient's body position; the position of the head; axillary temperature; pulse and respiration rates; blood pressure; and pulse oximetry. RESULTS: In vitro difference between the initial pressure (IP) and measured pressure (MP) was statistically significant (P < 0.05). The difference between the IP and MP was significant when selecting for various tube brands (P < 0.05). In the clinical set-up, 207 measurements were performed and the CP was >30 cm H2O in 6.28% of the recordings, 20-30 cm H2O in 42.0% of the recordings, and <20 cm H2O in 51.69% of the recordings. CONCLUSION: The systematic CP measurement in chronically tracheostomized, spontaneously breathing patients showed high variability, which was independent of tube brand, size, type, or time of placement. Consequently, measurements should be made more frequently.

Effect of melatonin on vascular responses in aortic rings of aging rats.

In old animals a marked reduction in endothelium-dependent relaxation occurs. Since there is evidence that the endothelial dysfunction associated with aging may be partly related to the local formation of reactive oxygen species, the purpose of this study was to examine the effect of the natural antioxidant melatonin (10(-5)mol/l) on in vitro contractility of aged aortic rings under conditions of increased oxidative stress (40 m mol/l glucose concentration in medium). Experiments were carried out in 18-20 months old, Wistar male rats, using adult (6-7 months old) animals as controls. A higher plasma lipid peroxidation was found in aged rats as compared to the younger ones. In a first experiment, dose-response curves for acetylcholine-induced relaxation of aortic rings were conducted. Analyzed as a main factor in a factorial ANOVA, age decreased and melatonin augmented the relaxing response to acetylcholine. melatonin's restoring effect on aortic ring relaxation was found in aged aortic rings only and was more pronounced in the presence of a high glucose medium. In a second experiment, the effect of melatonin on the contractility response to phenylephrine of intact or endothelium-denuded aortic rings obtained from aged or control rats was examined in normal or high glucose medium. A main factor analysis in the factorial ANOVA indicated that age and operation augmented, and melatonin decreased, aortic ring contractility response to phenylephrine. Melatonin's restoring effect on aortic contractility was seen in aged aortic rings. The effect of age or a high glucose medium on phenylephrine-induced contractility was more pronounced in the absence of an intact endothelium. Aging did not affect the relaxant response of intact or endothelium-denuded rings to sodium nitroprusside. The results support the improvement by melatonin of vascular response in aging rats, presumably via its antioxidant activity.