RESUMO
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.
Assuntos
Humanos , Recém-Nascido , Monitorização Transcutânea dos Gases Sanguíneos/instrumentação , Impedância Elétrica , Monitorização Fisiológica/instrumentação , Recém-Nascido Prematuro , Método Simples-Cego , Estudos Transversais , Estudos Cross-Over , Eletrodos , Monitorização Fisiológica/métodosRESUMO
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.