ABSTRACT
Abstract Objective: To verify if the connection of electrodes for heart and transcutaneous oxygen monitoring interfere with the measurement of electrical bioimpedance in preterm newborns. Methods: This was a prospective, blinded, controlled, cross-sectional, crossover study that assessed and compared paired measures of resistance (R) and reactance (Xc) by BIA, obtained with and without monitoring wires attached to the preterm newborn. The measurements were performed in immediate sequence, after randomization to the presence or absence of electrodes. The sample size calculated was 114 measurements or tests with monitoring wires and 114 without monitoring wires, considering for a difference between the averages of 0.1 ohms, with an alpha error of 10% and beta error of 20%, with significance <0.05. Results: No differences were observed between the R (677.37 ± 196.07 vs. 677.46 ± 194.86) and Xc (31.15 ± 9.36 vs. 31.01 ± 9.56) values obtained with and without monitoring wires, respectively, with good correlation between them (R: 0.997 and Xc: 0.968). Conclusion: The presence of heart and/or transcutaneous oxygen monitoring wires connected to the preterm newborn did not affect the values of R or Xc measured by BIA, allowing them to be carried out in this population without risks.
Resumo Objetivo Verificar se a conexão de eletrodos e os fios de monitoração cardíaca e transcutânea de oxigênio interferem na aferição da bioimpedância elétrica em recém-nascidos pré-termo (RNPT). Metodologia Estudo prospectivo, cego, randomizado, transversal, crossover, em que foram mensuradas e comparadas medidas pareadas de resistência (R) e reatância (Xc) por meio da BIA, obtidas com e sem os fios de monitoração acoplados aos RNPT. As medidas foram feitas em sequência imediata, após aleatorização para a presença ou ausência dos eletrodos. O tamanho amostral calculado foi de 114 aferições ou exames com fios de monitoração e 114 sem fios de monitoração, foi calculado para uma diferença entre as médias de 0,1 ohms, com erro alfa de 10% e erro beta de 20%, com significância < 0,05. Resultados Não foram observadas diferenças entre os valores de resistência (677,37 ± 196,07 vs. 677,46 ± 194,86) e reatância (31,15 ± 9,36 vs. 31,01 ± 9,56) obtidos com e sem fios de monitoração respectivamente, com boa correlação entre ambos (resistência: 0,997 e reatância: 0,968). Conclusão A presença de fios de monitoração cardíaca e/ou transcutânea de oxigênio não interferiu nos valores da resistência ou da reatância aferidos pela BIA em RNPT. Recomenda-se, então, a feitura desse exame, sem riscos, para essa população.
Subject(s)
Humans , Infant, Newborn , Blood Gas Monitoring, Transcutaneous/instrumentation , Electric Impedance , Monitoring, Physiologic/instrumentation , Infant, Premature , Single-Blind Method , Cross-Sectional Studies , Cross-Over Studies , Electrodes , Monitoring, Physiologic/methodsABSTRACT
Monitoring cerebral oxygenation with near infrared spectroscopy may identify periods of cerebral desaturation and thereby the patients at risk for perioperative neurocognitive issues. Data regarding the performance of near infrared spectroscopy monitoring during deep hypothermic circulatory arrest are limited. The current study presents data regarding use of a commercially available near infrared spectroscopy monitor during deep hypothermic circulatory arrest in paediatric patients undergoing surgery for congenital heart disease. The cohort included 8 patients, 2 weeks to 6 months of age, who required deep hypothermic circulatory arrest for repair of congenital heart disease. The baseline cerebral oxygenation was 63 +/- 11% and increased to 88 +/- 7% after 15 min of cooling to a nasopharyngeal temperature of 17-18 degrees C on cardiopulmonary bypass. In 5 of 8 patients, the cerebral oxygenation value had achieved its peak value (either >or=90% or no change during the last 2-3 min of cooling on cardiopulmonary bypass). In the remaining 3 patients, additional time on cardiopulmonary bypass was required to achieve a maximum cerebral oxygenation value. The duration of deep hypothermic circulatory arrest varied from 36 to 61 min (43.4 +/- 8 min). After the onset of deep hypothermic circulatory arrest, there was an incremental decrease in cerebral oxygenation to a low value of 53 +/- 11%. The greatest decrease occurred during the initial 5 min of deep hypothermic circulatory arrest (9 +/- 3%). Over the entire period of deep hypothermic circulatory arrest, there was an average decrease in the cerebral oxygenation value of 0.9% per min (range of 0.5 to 1.6% decline per minute). During cardiopulmonary bypass, cooling and deep hypothermic circulatory arrest, near infrared spectroscopy monitoring followed the clinically expected parameters. Such monitoring may be useful to identify patients who have not achieved the highest possible cerebral oxygenation value despite 15 min of cooling on cardiopulmonary bypass. Future studies are needed to define the cerebral oxygenation value at which neurological damage occurs and if interventions to correct the decreased cerebral oxygenation will improve perioperative outcomes.
Subject(s)
Blood Gas Analysis , Blood Gas Monitoring, Transcutaneous/instrumentation , Brain Ischemia/diagnosis , Cardiopulmonary Bypass/instrumentation , Circulatory Arrest, Deep Hypothermia Induced/instrumentation , Electroencephalography/methods , Female , Heart Defects, Congenital/blood , Humans , Infant , Infant, Newborn , Male , Outcome Assessment, Health Care , Retrospective Studies , Spectroscopy, Near-Infrared/statistics & numerical data , Time FactorsABSTRACT
La comprensión de la cinética del dióxido de carbono, como la cuantificación de su presencia en los tejidos del organismo humano, hacen sospechar su repercusión en distintos aspectos de la fisiología. La aparición de la capnometría y posteriormente de la capnografía posibilitó que el anestesiólogo y el médico intensivista, gozaran de la obtención de datos en forma continua que traducen distintas variaciones de la fisiología cardiopulmonar, detección de desconexiones de los sistemas de ventilación, intubaciones endoesofágicas, dificultades en el metabolismo con alteraciones en la producción y eliminación del CO2, pronóstico de maniobras de resucitación cardiopulmonar, repercusión del CO2 exógeno (procedimientos videoscópicos), estimaciones del espacio muerto respiratorio, trastornos ventilatorios obstructivos y restrictivos. Todas éstas utilidades y otras que se pudieran inferir de la capnografía no desplazan al valor arterial del dióxido de carbono sino por el contrario, la diferencia arterio-alveolar de CO2 es un dato más que indica el estado en que se encuentra la distribución de los índices ventilación/perfusión de los pulmones, obteniendo a partir de allí elementos que conducirán a las decisiones para el manejo respiratorio correspondiente.
Subject(s)
Humans , Carbon Dioxide/pharmacokinetics , Carbon Dioxide/physiology , Carbon Dioxide/metabolism , Blood Gas Monitoring, Transcutaneous/instrumentation , Blood Gas Monitoring, Transcutaneous/methods , Ventilation-Perfusion Ratio/physiology , Respiratory Dead SpaceABSTRACT
El las crisis del asma se desarrollan alteraciones del intercambio gaseoso con tendencia a la acidosis e hipoxemia. La saturación arterial de oxígeno (oximetría de pulso) es un método sencillo y útil para valorar las condiciones de oxigenación. Se estudiaron 35 pacientes con crisis asmática de siete a 14 años, realizando oximetría de pulso y espirometría basal y posterior a nebulizaciones de salbutamol. Se concluye que la oximetría representa una herramienta útil y sencilla para valorar objetivamente la evolución y las complicaciones de una crisis aguda; sin embargo, no es predictiva para decidir una conducta terapéutica