Evaluation of the bioimpedance technique in newborns with a focus on electrode positioning: A prospective, randomized, crossover study.

BACKGROUND: Bioelectrical impedance analysis (BIA) is a good alternative for assessing total body water in newborns. However, the lack of standardization of the method for its use in the neonatal population raises doubts about its reliability and external validation. OBJECTIVE: To compare resistance (R) and reactance (Xc) values measured by BIA with electrodes placed in the anatomical position and with electrodes placed at 5-cm intervals. METHOD: Prospective, randomized, crossover study, in which R and Xc values were measured using monofrequency BIA. The choice of the first position of the electrodes to be analyzed in each NB was performed by a simple randomization, and subsequent measurements were performed in rapid succession. The calculated sample size was 203 evaluations. The paired t test was used to compare the means of R and Xc, and the Bland-Altman plot and linear regression were used to analyze how much the measured values were influenced by the electrode position. RESULTS: Significant differences were found in the R (855.25 ± 147.79 vs 618.95 ± 93.28 Ω) and Xc (50.94 ± 17.34 vs 39.76 ± 18.35 Ω) values measured with electrodes in the anatomical position and at 5-cm intervals, respectively. The electrodes in the anatomical position produced R and Xc values 37.7% and 16.6%, respectively, higher on average when compared with 5-cm intervals. CONCLUSIONS: The distance between the electrodes influences the measurement of R and Xc by BIA. These results highlight the importance of defining a standard for the placement of electrodes in newborns for the use of these measures in neonatal clinical practice.

Interference of heart and transcutaneous oxygen monitoring in the measurement of bioelectrical impedance analysis in preterm newborns / Interferência da monitoração cardíaca e transcutânea de oxigênio na aferição da bioimpedância elétrica em recém-nascidos pré-termo

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.

Interference of heart and transcutaneous oxygen monitoring in the measurement of bioelectrical impedance analysis in preterm newborns.

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.

Aplicação de protocolo proposto pela Agência Nacional de Vigilância Sanitária para uso de antibióticos em recém-nascidos de muito baixo peso / Implementation of a protocol proposed by the brazilian National Health Surveillance Agency for antibiotic use in very low birth weight infants

OBJETIVO: Analisar a aplicação de um protocolo proposto pela Agência Nacional de Vigilância Sanitária (ANVISA) para aprimorar o diagnóstico de sepse em recém-nascidos de muito baixo peso. MÉTODOS: Estudo prospectivo que avaliou a aplicação de protocolo envolvendo critérios clínicos e laboratoriais (escore hematológico de Rodwell e dosagem seriada da proteína C-reativa), recomendado pela ANVISA, para aprimorar o diagnóstico de sepse neonatal em recém-nascidos de muito baixo peso. Participaram do estudo todos os pacientes que nasceram e permaneceram na Unidade Neonatal até a alta ou óbito, e foram excluídos aqueles com doenças congênitas. Os principais desfechos analisados entre os recém-nascidos antes da aplicação do protocolo (2006-2007) e após a aplicação do mesmo (2008) foram as taxas de sepses precoce e tardia, o uso de antimicrobianos e a mortalidade. As médias foram comparadas por meio de teste t e as variáveis categóricas pelo teste Qui-quadrado (χ2); o nível de significância para todos eles foi fixado em 95%. RESULTADOS: Foram incluídos no estudo 136 recém-nascidos de muito baixo peso. Não houve diferença entre os grupos em relação às características clínicas gerais nos períodos estudados. Houve, no entanto, redução na quantidade de diagnóstico de sepse precoce provável (p < 0,001), de uso de esquemas antimicrobianos (p < 0,001) e da mortalidade geral e associada à sepse (p = 0,009 e p = 0,049, respectivamente). CONCLUSÃO: A utilização do protocolo permitiu aprimorar o diagnóstico de sepse, reduzindo o diagnóstico de sepse precoce provável, promovendo, desta forma, o uso racional de antimicrobianos na população estudada.

OBJECTIVE: To analyze the implementation of a protocol proposed by the Brazilian National Health Surveillance Agency (Agência Nacional de Vigilância Sanitária - ANVISA) to improve sepsis diagnosis in very low birth weight newborns. METHODS: This was a prospective study that evaluated the implementation of a protocol involving clinical and laboratory criteria (hematologic scoring system of Rodwell and C-reactive protein serial measurements), recommended by ANVISA, to improve the diagnosis of neonatal sepsis in very low birth weight newborns. The study included all patients who were born and remained in the neonatal intensive care unit until discharge or death, and excluded those with congenital diseases. The main outcomes measured in newborns before (2006-2007) and after implementation of the protocol (2008) were the rates of early and late sepsis, use of antibiotics, and mortality. Means were compared by Student's t-test and categorical variables were compared by the chi-squared test; the significance level for all tests was set at 95%. RESULTS: The study included 136 newborns with very low birth weight. There was no difference between groups regarding general clinical characteristics in the studied periods. There was, however, a decrease in the number of diagnoses of probable early-onset sepsis (p < 0.001), use of antimicrobial regimens (p < 0.001), and overall mortality and infection-related mortality (p = 0.009 and p = 0.049, respectively). CONCLUSION: The implementation of the protocol allowed improvement of sepsis diagnosis by reducing the diagnosis of probable early-onset sepsis, thus promoting efficient antimicrobial use in this population.

Implementation of a protocol proposed by the Brazilian National Health Surveillance Agency for antibiotic use in very low birth weight infants.

OBJECTIVE: To analyze the implementation of a protocol proposed by the Brazilian National Health Surveillance Agency (Agência Nacional de Vigilância Sanitária - ANVISA) to improve sepsis diagnosis in very low birth weight newborns. METHODS: This was a prospective study that evaluated the implementation of a protocol involving clinical and laboratory criteria (hematologic scoring system of Rodwell and C-reactive protein serial measurements), recommended by ANVISA, to improve the diagnosis of neonatal sepsis in very low birth weight newborns. The study included all patients who were born and remained in the neonatal intensive care unit until discharge or death, and excluded those with congenital diseases. The main outcomes measured in newborns before (2006-2007) and after implementation of the protocol (2008) were the rates of early and late-onset sepsis, use of antibiotics, and mortality. Means were compared by Student's t-test and categorical variables were compared by the chi-squared test; the significance level for all tests was set at 95%. RESULTS: The study included 136 newborns with very low birth weight. There was no difference between groups regarding general clinical characteristics in the studied periods. There was, however, a decrease in the number of diagnoses of probable early-onset sepsis (p<0.001), use of antimicrobial regimens (p<0.001), and overall mortality and infection-related mortality (p=0.009 and p=0.049, respectively). CONCLUSION: The implementation of the protocol allowed improvement of sepsis diagnosis by reducing the diagnosis of probable early-onset sepsis, thus promoting efficient antimicrobial use in this population.

Determining the least time required for measuring energy expenditure in premature neonates.

OBJECTIVE: To compare O2 consumption, CO2 production, respiratory quotient and resting metabolic rate in premature neonates measured for 5 and 10 min steady-state periods and 15 and 20 min non-steady-state periods versus a 2-h measurement period. METHODS: A prospective study with neonates evaluated by indirect calorimetry. The measurements from the 5, 10, 15, and 20 min periods were taken based on the printout data from the IC monitor at an interval of 1 h before the beginning feeding and were contained in the 2-h measurement. The 5- and 10-min measurements followed the steady-state criterion. RESULTS: We evaluated 35 premature neonates appropriate for gestational age (born at 28-34 weeks' gestation). Mean age was 20 days+/-9 (median 14 days) and mean weight was 1530+/-270 g (median 1510 g). There was no statistically significant difference between mean VO2, VCO2, respiratory quotient and energy expenditure at 5, 10, 15, and 20 min and 2 h. CONCLUSIONS: The 5 and 10 min steady-state measurements or a measurement of more than 15 min without reaching steady state produce results similar to those of 2 h measurements.

[Evaluation of the nutritional status at 40 weeks corrected gestational age in a cohort of very low birth weight infants]. / Avaliação dos fatores associados ao estado nutricional na idade corrigida de termo em recém-nascidos de muito baixo peso.

OBJECTIVE: To evaluate the nutritional status at term of a cohort of newborn babies with birth weights of less than 1,500 g and to correlate this with nutritional practices and clinical variables. METHODS: Very low birth weight infants admitted to eight neonatal intensive care units from November 1999 to April 2000 were studied prospectively. The units were defined as Type I if they employed aggressive nutritional support techniques and Type II if other nutritional practices were used. Babies were defined as malnourished if their z-score for weight was less than or equal to -2 on the Canadian Perinatal Surveillance System growth curves. Data were analyzed using multivariate linear regression and logistic regression. The study was approved by the Committee for Ethics in Research. RESULTS: Sixty-three percent (126/200) of the study population were classified as being malnourished at term. Weight at term (corrected gestational age) showed a direct correlation with birth weight, but an indirect correlation with the length of stay, gestational age at birth, time to regain birth weight and CRIB score (p < 0.05). Small for gestational age infants had a 12.19 times greater chance of being malnourished at term. Being born at a Type I unit reduced the risk of malnutrition at term by 2.17 times, male sex reduced this risk by 0.4 times and achieving total enteral nutrition by the 10th day of life reduced it by 1.97 times (p < 0.03). CONCLUSIONS: The most effective means of preventing babies being malnourished at term is by encouraging perinatal practices aimed at preventing restricted intrauterine growth, in addition to giving priority to aggressive nutritional management.

Avaliação dos fatores associados ao estado nutricional na idade corrigida de termo em recém-nascidos de muito baixo peso / Evaluation of the nutritional status at 40 weeks corrected gestational age in a cohort of very low birth weight infants

OBJETIVO: Avaliar a adequação do peso ao termo em uma coorte de recém-nascidos com peso de nascimento menor que 1.500 g e correlacioná-la a variáveis clínicas e nutricionais. MÉTODOS: Estudo longitudinal onde recém-nascidos de muito baixo peso de oito hospitais (divididos em duas categorias: tipo I - aporte nutricional agressivo; tipo II - outras práticas) foram acompanhados prospectivamente de novembro de 1999 a abril de 2000. O estado nutricional foi avaliado pelo escore z, sendo considerado como desnutrição o escore z menor ou igual a -2, segundo a curva do Canadian Perinatal Surveillance System. Os dados foram analisados por meio de regressão linear múltipla e regressão logística. Este estudo foi aprovado pelo Comitê de Ética em Pesquisa. RESULTADOS: 63 por cento da população estudada (126/200) foi classificada como desnutrida ao termo. O peso ao termo apresentou correlação negativa com o tempo de internação, com a idade gestacional ao nascimento, com o tempo para a recuperação do peso de nascimento e com o clinical risk index for babies (p < 0,05). Ter sido classificado como pequeno para a idade gestacional aumentou a chance de ser desnutrido ao termo em 12,19 vezes. Ter nascido nas unidades tipo I, ser do sexo masculino e ter atingido dieta enteral plena em até 10 dias de vida reduziu o risco de desnutrição ao termo em 2,17, 0,4 e 1,97 vezes, respectivamente (p < 0,03). CONCLUSÕES: A forma mais eficaz de prevenir a desnutrição nos recém-nascidos prematuros é estimular práticas perinatais, objetivando a prevenção da restrição do crescimento intra-uterino, além de priorizar uma abordagem nutricional mais agressiva.

[Assessment of the energy content of human milk administered to very low birth weight infants]. / Análise do conteúdo energético do leite humano administrado a recém-nascidos de muito baixo peso ao nascimento.

OBJECTIVE: To evaluate and compare the energy content in fresh and processed human milk administered to very low birth weight infants born in the Institute Fernandes Figueira. METHODS: Samples of 0.5 ml of fresh and processed human milk were evaluated as for the fat percentile and energy content, which was calculated by mathematical formulas. Four hundred and sixty two human milk samples were analyzed, 401 of processed human milk and 61 of fresh human milk. RESULTS: The median and the standard deviation of the fat percentile checked was 2.9+/-1.2% in the processed samples and 8.9+/-4.6% in the fresh samples (p < 0.001). The median and the standard deviation of the energy content calculated was 53.6+/-7.2 kcal/100 ml in processed samples and 85.9+/-27.9 kcal/100 ml in fresh samples (p < 0.001). CONCLUSION: The processed human milk samples had less energy content and less fat than fresh human milk samples suggesting that the complex processes of the human milk manipulation and administration can determine losses in energy content.

Análise do conteúdo energético do leite humano administrado a recém-nascidos de muito baixo peso ao nascimento / Assessment of the energy content of human milk administered to very low birth weight infants

OBJETIVO: Avaliar e comparar o conteúdo energético do leite humano cru e do leite humano processado oferecidos aos recém-nascidos com peso de nascimento menor que 1.500 g no Instituto Fernandes Figueira. MÉTODOS: Foram avaliadas alíquotas com 0,5 ml de leite humano cru e de leite humano processado, determinando-se primeiramente o crematócrito e, posteriormente, por meio da aplicação de fórmulas matemáticas, o teor energético. Foram avaliadas 462 amostras de leite humano, sendo 401 de leite humano processado e 61 de leite humano cru. RESULTADOS: A média do percentual de gordura obtida foi de 3,0±1,2 por cento no leite humano processado e de 8,9±4,6 por cento no leite humano cru (p < 0,001). A média do conteúdo energético calculado foi de 53,6±7,2 kcal/100 ml no leite humano processado e de 85,9±27,9 kcal/100 ml no leite humano cru (p < 0,001). CONCLUSÃO: Foram encontrados percentual de gordura e conteúdo energético significativamente menores no leite humano processado em relação ao leite humano cru, sugerindo que o processo de manipulação pode afetar a qualidade do leite humano processado ofertado aos recém-nascidos.

Erro médico em pacientes hospitalizados / Medical errors in hospitalized patients

Objetivo: o presente artigo tem por objetivo revisar a literatura e discutir a questão do erro médico em pacientes hospitalizados, enfocando sua conceituação. incidência, fatores predisponentes e mecanismos de prevenção. Aborda, em especial, erros e eventos adversos com drogas envolvendo recém-nascidos e pacientes pediá-tricos.Métodos: revisão bibliográfica utilizando banco de dados Medline, selecionando-se aqueles com informações atuais e relevantes.Resultados: mesmo assumindo que a notificação do erro médico não ocorre em um grande número de eventos, é importante notar que sua incidência é muito maior do que julgamos. Só nos EUA, cerca de um milhão de pacientes por ano são vítimas de erros médicos e eventos adversos com drogas. Segundo recente metanálise, esta é,hoje, a quarta causa de morte nos EUA. Em unidades de terapia intensiva neonatal e pediátrica, nas quais é grande a complexidade e a freqüência de procedimentos, a ocorrência de erros é maior. Estima-se que quinze por cento das internações em unidades de terapia intensiva neonatal sejam acompanhadas de erro médico. A maioria destes erros acontece durante o período noturno, e envolve administração incorreta de droga (35por cento) e erro na interpretação da prescrição (26por cento). Fatores ambientais (barulho, calor), psicológicos (tédio, ansiedade, estresse) e fisiológicos (fadiga, sono) contribuem para a ocorrência de erros. Recente estudo revela que após um plantão de 24 horas, sem dormir, o desempenho psicomotor de um profissional de saúde é semelhante ao de um indivíduo legalmente bêbado (nível sérico alcoólico maior ou igual a 0,08 por cento). Conclusões: mesmo em profissionais conscientes, erros sãoacompanhantes inevitáveis da condição humana. A prevenção de erros deve basear-se na busca de causas reais, que geralmente incluem erros no sistema de organização e implementação do serviço. Erros devem ser aceitos...

[Medical errors in hospitalized patients]. / Erro médico em pacientes hospitalizados.

OBJECTIVE: To review the current literature and to discuss medical errors in hospitalized patients emphasizing its incidence, predisposing factors and prevention mechanism. Special attention is given to medication errors and adverse drug events in newborn infants and pediatric patients. SOURCES: Bibliographic review of the current literature through electronic search in Medline data-base, with selection of the most relevant articles. SUMMARY OF THE FINDINGS: Even though most medical errors are not reported, it is important to notice that its incidence is greater than previously assumed. In the USA, approximately one million of patients/year are victims of medical errors and adverse drug events. Today, deaths resulting from these episodes are the fourth cause of mortality in the USA. In neonatal and pediatric intensive care units, where the complexity and frequency of technical procedures are high, medical errors are frequent. Fifteen percent of all admissions to a neonatal intensive care unit is followed by medical errors. Most of these errors occur during night shifts and include incorrect administration of drugs (35%) and errors regarding the interpretation of medical prescription (26%). Environmental factors (noise, heat), psychological factors (anxiety, stress) and physiologic factors (fatigue, absence of sleep) contribute to the occurrence of errors. Recent study shows that after working 24 hours without sleeping, the performance of a health professional is similar to a legally drunk person (serum alcohol level > or =0.08%). CONCLUSIONS: Errors are part of human behavior. The prevention of errors should include a careful review of the organizational system. Medical errors should be seen as an opportunity to change or re-structure the system and to improve the quality of health care delivered and patient safety.