El espacio muerto (VD/VT) como predictor de éxito en la extubación de pacientes postquirúrgicos de cirugía cardiovascular pediátrica / Dead space (VD/VT) as a predictor of successful extubation of patients after pediatric cardiovascular surgery

Introducción: La ventilación mecánica (VM) forma parte de la recuperación postoperatoria (PO) de niños con cirugía de cardiopatía congénita, pero su uso no está exento de riesgos. El fracaso de extubación (FE) se ha asociado con internaciones prolongadas, aumento de complicaciones y mortalidad. El objetivo es determinar un valor de Vd/Vt predictor de extubación exitosa (EE). Material y métodos: estudio de cohorte prospectivo y observacional realizado del 1 de Enero al 31 de Diciembre de 2016 en niños menores de 6 meses cursando PO de cirugía cardiovascular con circulación extracorpórea (CEC) con requerimientos de VM por más de 48 horas. En los mismo se analizó el éxito o fracaso de extubación. Previo a la extubación se registraron valores de mecánica respiratoria; Vd/Vt, CO2 espiratoria final, Vt/kg, etc. Otras variables registradas: edad, sexo, peso, requerimiento de VM antes de la cirugía, fisiología de ventrículo único, duración de VM, complicaciones, duración de la internación y mortalidad. Las variables continuas se describieron como mediana y rango intercuartilo (25-75) y se compararon con prueba de Wilcoxon, las categóricas como proporciones o porcentajes y se analizaron con chi2 . Se efectuó un análisis bivariado con diferentes puntos de corte de Vd/Vt pre extubación para realizar un análisis de sensibilidad del valor predictivo de EE. Resultados: Se evaluó Vd/Vt en 67 pacientes, tres se eliminaron por parálisis cordal (1) y parálisis del diafragma (2). Mediana de edad 23 días (10-55), peso 3.2 Kg (2.89- 3.88), días de VM 5 (3-7), días de internación 15 (2- 128), mortalidad 7,8%. Se extubaron con éxito 76% de los pacientes (50/64). Las características demográficas de los pacientes, la mecánica respiratoria, gases de sangre arterial y EtCO2 no tuvieron asociación significativa con EE. Un Vd/Vt pre extubación < 0,53 se asoció con EE. Conclusión: En la población estudiada un valor de Vd/Vt <0,53 se asoció con EE. Los pacientes con ventrículo único presentaron mayor FE.(AU)

Introduction: Mechanical ventilation (MV) is part of postoperative (PO) recovery of children with congenital heart disease surgery, but is not without risks. Extubation failure (EF) has been associated with prolonged hospital stays and increased complication and mortality rates. The goal is to determine the value of Vd/Vt as a predictor of successful extubation (SE). Material and methods: A prospective and observational cohort study was conducted from January 1 to December 31, 2016, in children under 6 months of age undergoing cardiovascular surgery with extracorporeal circulation (ECC) and requiring MV for more than 48 hours. Intubation success or failure was evaluated. Prior to extubation, respiratory mechanics values, such as Vd/Vt, final expiratory CO2, and Vt/kg, were recorded. Other variables, including age, sex, weight, VM requirement before surgery, single ventricle physiology, VM duration, complications, length of hospital stay, and mortality were also recorded. Continuous variables were described as median and interquartile range (25-75) and compared with the Wilcoxon test. Categorical variables were described as proportions or percentages and analyzed with chi2. Bivariate analysis was performed with different pre-extubation Vd/Vt cut-off points to analyze the sensitivity of the predictive value for SE. Results: Vd/Vt was evaluated in 67 patients; three were excluded because of vocal fold (1) and diaphragm paralysis (2). Median age was 23 days (10-55), weight 3.2 Kg (2.89- 3.88), days on MV 5 (3-7), length of hospital stay 15 (2- 128), and mortality rate 7.8%. Overall, 76% of patients (50/64) were successfully extubated. Patient demographics, respiratory mechanics, arterial blood gases, and EtCO2 were not significantly associated with SE. A pre-extubation Vd/ Vt < 0.53 was associated with SE. Conclusion: In this series of patients, a Vd/Vt value of <0.53 was associated with SE. EF was increased in patients with a single ventricle (AU)

Soporte nutricional en la primera semana post operatoria en niños menores de 3 meses que requieren cirugía cardiovascular / Nutritional support in the first postoperative week in children under 3 months of age requiring cardiovascular surgery

El periodo post operatorio a la cirugía cardiaca es complejo y la nutrición juega un rol fundamental dentro de los cuidados. Luego de una cirugía que requiere bypass cardiopulmonar, los neonatos experimentan una profunda respuesta metabólica al stress. Si esta respuesta ocurre sin un soporte nutricional adecuado, la malnutrición lleva a la pérdida de masa magra y al deterioro de la función de órganos vitales. Objetivo: Describir el estado nutricional y el aporte nutricional alcanzado en niños menores de 3 meses con cirugía cardiovascular durante la implementación de un programa de soporte nutricional intensivo evaluado al ingreso, al tercer y séptimo día post operatorio. Resultados: Se estudiaron 64 pacientes. Se logró la implementación de nutrición parenteral total (NPT) en todos los pacientes que ingresaron al protocolo y que requirieron nutrición parenteral. El promedio de volumen recibido en este periodo fue de 50 ml/kg/día (rango entre 25 y 80 ml/kg/día).Las evaluaciones al ingreso, a las 72 hs. y a la semana post operatoria mostraron que el 70%, 69%y 62,7% respectivamente de los pacientes no llegaron a las 67 kcal/kg/ día propuestas para la intervención nutricional para nuestro objetivos. Por el contrario se encontró que el aporte energético enteral y parenteral administrado en los 3 tiempos estudiados logró cubrir el 100% de los requerimientos metabólicos en reposo (REE) estimados por las fórmulas de Schofield y WHO con resultados similares sin diferencias significativas entre ambas. Conclusión: a pesar de no haber logrado cumplir con el objetivo nutricional calórico propuesto por nuestra intervención nutricional, el mismo logro cubrir el 100% del REE calculado por fórmulas (AU)

The postoperative period after heart surgery is complex and nutrition has a key role in the care process. After a surgery that requires cardiopulmonary bypass, neonates have a severe metabolic response to stress. If this response occurs without adequate nutritional support, malnourishment leads to loss of lean body mass and deterioration of vital organ function. Aim: To describe the nutritional status and nutritional support achieved in infants under 3 months of age who underwent cardiovascular surgery during the implementation of an intensive nutritional support program evaluated on admission and on the third and seventh day postoperatively. Results: Overall, 64 patients were studied. The implementation of total parenteral nutrition (TPN) was achieved in all patients that were included in the protocol and required parenteral nutrition. Median volume administered in this period was 50 ml/kg/day (range, from 25 and 80 ml/kg/day). Evaluation on admission, at 72 hs. and at 1 week postoperatively showed that 70%, 69%, and 62.7% of the patients, respectively, did not achieve the 67 kcal/kg/day proposed as the aim for the nutritional intervention. Conversely, it was found that enteral and parenteral energy delivery administered in the three time points was able to cover 100% of the resting energy expenditure (REE) calculated by the Schofield and WHO formalas with similar results without significant differences. Conclusion: Although the nutritional caloric aim a proposed by our nutritional intervention could not be reached, it was able to cover 100% of the REE calculated using the formulas (AU)

Estudio comparativo de dos modos de ventilación no invasiva para retirar la asistencia respiratoria mecánica en lactantes post-operatorios de cirugía cardiovascular / Comparative study of two modalities of non-invasive ventilation for the weaning from mechanical ventilation of post-cardiovascular surgery infants

La mejor estrategia en el post-quirúrgico de cardiopatías congénitas para promover la extubación precoz y destete de asistencia respiratoria mecánica (ARM) con ventilación no invasiva (VNI) todavía no ha sido establecida. El objetivo es comparar eficacia de la presión positiva continua en la vía aérea (CPAP) vs presión positiva con dos niveles en la vía aérea (BIPAP) en la extubación electiva de estos pacientes. Es un estudio prospectivo entre el 1 de junio de 2008 y 31 marzo de 2010. Se randomizaron los pacientes para extubación electiva: modo CPAP o BIPAP. Se registraron datos demográficos y del procedimiento quirúrgico, entre otros. El fracaso de VNI fue definido como reintubación dentro de las 72 hs posteriores a la extubación o más de un criterio de intubación. Durante el periodo de estudio 1438 pacientes fueron admitidos en UCI35. En el grupo BIPAP se randomizaron 53 pacientes, de los cuales se extubaron exitosamente 49 (92%), pero 4 se reintubaron debido a falla cardiaca. En el grupo CPAP se randomizaron 46 y fallaron en la extubación 18 (39%) debido a múltiples episodios de desaturación y apneas. De éstos, 11 requirieron reintubación endotraqueal y ARM. En 7 pacientes, se pasó a modo BIPAP y permanecieron extubados, aunque el cruzamiento no fue parte del diseño de este estudio. En el destete de ARM de los pacientes post-quirúrgicos de cardiopatías congénitas, el uso de BIPAP fue más efectivo que CPAP. En esta última modalidad se presentaron mayor número de fracasos de VNI (AU)

The best strategy for early extubation and weaning from mechanical respiration (MV) with non-invasive ventilation (NIV) in post-surgical congenital heart defect patients has not been established yet. The aim of this study was to compare the efficacy of continuous positive airway pressure CPAP) vs bi-level positive airway pressure (BIPAP) in the elective extubation of these patients. A prospective study was conducted between June 1, 2008 and March 31, 2010. Patients that were candidates for elective extubation were randomized to CPAP or BIPAP. Data on demographics and surgical procedure, among others, were recorded. Failure of NIV was defined as the need for reintubation within 72 hours after extubation or more than one criterion for intubation. Over the study period, 1438 patients were admitted to ICU 35. Fifty-three patients were randomized to BIPAP, of whom 49 (92%) were successfully extubated; however, four were reintubated due to heart failure. Forty-six patients were randomized to CPAP. Extubation failed in 18 (39%) due to multiple episodes of desaturation and apneas. Eleven of 18 required endotracheal reintubation and mechanical ventilation. Seven patients were switched to BIPAP and remained extubated, although the switch was not part of the study design. In the weaning of post-surgical congenital heart defect patients from MV, BIPAP was more effective than CPAP. In the latter modality, the incidence of NIV failure was higher (AU)

Regional venous oxygen saturation versus mixed venous saturation after paediatric cardiac surgery.

BACKGROUND: Central venous oxygen saturation (ScvO2) remains the gold standard surrogate for tissue oxygen extraction in paediatric cardiac surgery. Near-infrared spectroscopy (NIRS) has been developed as a non-invasive diagnostic tool for regional oxygen saturation. The aim was to compare regional oxygen saturation measured by NIRS with ScvO2 in postoperative paediatric cardiac patients. METHODS: In this prospective study, we included newborns and infants younger than 45 days undergoing heart surgery. We recorded continuous ScvO2 and NIRS regional saturation placed on the forehead (B) and right flank (S) for 48 h postoperatively. A Bland-Altman's analysis was used to assess the agreement between these measurements. RESULTS: A total of 23 patients were included with a median age of 12 days (2-46) and median weight of 3.1 kg (2.3-4.47). The mean difference (MD) ScvO2- B NIRS was 10.45% with limits of agreement (LOA) -17.23 to 38.13% and ScvO2- S NIRS MD 7.16% with LOA: -25.51 to 39.84%. The single ventricle ScvO2- S NIRS subgroup had MD within ± 5%; however, wide LOA was observed. The remaining subgroups showed MD nearly above ± 5%, with wide LOA. CONCLUSIONS: The regional oxygen saturation of brain and kidney did not match ScvO2 as estimation of global tissue perfusion. Nevertheless, NIRS may still provide information regarding regional circulation that may help in the management of neonatal cardiac surgery patients.

How informed can consent be? New light on comprehension among elderly people making decisions about enteral tube feeding.

Elderly people in long-term care facilities do not understand much about various medical procedures, including enteral feeding. After presentation of empirically precise information about enteral tube feeding, residents in both long-term care and community-dwelling groups showed significant improvement in their understanding. The community-dwelling group showed even greater improvement. For both, comprehension was negatively related to age and depression scores, but positively related to IQ, reading comprehension, social support, and mental status. The MMSE proved the best predictor of comprehension. Implications of the results are discussed.

Decisions about enteral tube feeding among the elderly.

OBJECTIVE: To determine choices about enteral tube feeding and factors associated with deciding to accept or forego this intervention in a group of ambulatory non-demented older individuals. DESIGN: Descriptive survey. SETTING AND PARTICIPANTS: Thirty four volunteers from a senior adult day center and 34 volunteers from the residential care section of a multilevel long-term care institution, mean age 77.8. INTERVENTION: Structured interview using a hypothetical clinical vignette in simplified language, story-book format depicting an irreversibly and severely impaired state of health. MEASUREMENT: Choice of whether to accept or forego enteral tube feeding based on the clinical vignette. RESULTS: Thirty four (50%) decided to accept and 34 (50%) chose to forego enteral tube feeding in the situation presented in the vignette. No demographic, cognitive, or affective factors were associated with the decision. Presentation of the vignette and associated questions were not anxiety-provoking or upsetting to the vast majority of participants. CONCLUSION: A hypothetical clinical vignette depicting a state of severely impaired health resulted in 34 (50%) of 68 ambulatory non-demented older individuals deciding to accept enteral tube feeding. No factors we examined were strongly associated with the decision. The vignette and discussion were not anxiety-provoking when presented in the format used in this study. Advance-directive discussions about enteral tube feeding and other health care decisions, using understandable hypothetical clinical vignettes that describe risks and benefits that might influence decisions, should be encouraged in the practice of geriatric medicine.

Measuring functioning and health in the very old.

To assess the validity of brief multidimensional measures of health, we studied 155 new residents of a long-term care institution. We collected self-reported measures of various aspects of health, as well as performance-based measures of physical and cognitive function. For six similar health dimensions measured using two self-reported methods, the average correlation between paired health dimensions was 0.64 (nonpaired correlation = 0.36). When we compared self-reports and performance on three closely paired health concepts, the average correlation of paired concepts was 0.49 (nonpaired correlation = 0.22). In a factor analysis, similar health dimensions measured using different methods tended to load on the same factor. Except for manual performance, performance-based and self-reported measures of physical and role function loaded on one factor. We conclude that brief measures of health and self-reported physical functioning in very old persons have acceptable validity.