Reliability and reference values for diaphragmatic excursion, thickness, and thickening fraction and quadriceps femoris muscle thickness in full-term newborns evaluated by ultrasound.

To determine the diaphragm thickness, thickening fraction, and excursion and thickness of the quadriceps femoris muscle in full-term newborns and to evaluate the intra- and interrater reliability of these measurements. This was a prospective, observational clinical study including full-term newborns born within the first 48 h after birth. Serial measurements of the thickness, thickening fraction, and mobility of the diaphragm muscles and the thickness of the quadriceps muscle were obtained using ultrasound images. A total of 69 newborns with a mean gestational age of 39 weeks were included. The following measurements were obtained and are expressed as the mean (standard deviation): inspiratory diaphragm thickness, 0.19 cm (0.04); expiratory diaphragm thickness, 0.16 cm (0.04); diaphragm thickness fraction, 16.70 cm (10.27); diaphragmatic excursion, 0.68 cm (0.22); and quadriceps thickness, 0.99 cm (0.14). Intrarater reliability was assessed using intraclass correlation coefficients (ICCs). Excellent intrarater agreement was observed for the two groups of operators (ICC > 0.86, p < 0.001) for all measurements except for the diaphragm thickening fraction, which showed good agreement for both operator groups (ICC = 0.70, p < 0.001). Regarding interrater reliability, moderate agreement between the raters was observed in the means of all measures (ICC > 0.49, p < 0.001), except for the diaphragm thickening fraction, which showed poor agreement.    Conclusion: Good intrarater and moderate interrater reliability were achieved in ultrasound evaluations of the thickness and mobility of the diaphragm and quadriceps femoris muscles in full-term newborns, demonstrating the feasibility of this technique for clinical use. This pioneering study offers reference values for these muscles in a single study, allowing comparisons between different clinical conditions. What is Known: • Ultrasound is a highly reliable tool for muscle assessment that can be used to assess muscular atrophy in critically ill patients. • Muscle atrophy worsens the patient's condition and has been associated with worse outcomes. What is New: • To our knowledge, this is the first study to jointly evaluate the diaphragm and quadriceps muscle thickness and evaluate the reliability of all measurements. • Our study presents reference values for both muscles, enabling comparisons between different clinical conditions.

High-flow nasal cannula failure: can clinical outcomes determine early interruption?

OBJECTIVE: To evaluate the evolution of clinical outcomes in children with bronchiolitis who used a high-flow nasal cannula, and to determine after long of non-clinical improvement the therapy should be discontinued, and treatment should be escalated to other forms of ventilatory support. METHODS: An observational retrospective study of infants with bronchiolitis who used a high-flow nasal cannula. Patients were divided into two study groups according to success or failure of high-flow nasal cannula therapy, namely the Success Group and the Failure Group. The main demographics and clinical variables were assessed 30 minutes and 6 hours after initiating therapy until removal of the high-flow nasal cannula. RESULTS: A total of 83 children were studied and 18 children (21.7%) failed therapy. Among subjects with successful therapy, a significant decrease in respiratory rate (p<0.001), and a significant increase in peripheral oxygen saturation (p<0.001) were observed within 30 minutes. The Success Group was significantly different from the Failure Group after 6 hours, for both respiratory rate (p<0.01) and peripheral oxygen saturation (p<0.01). CONCLUSION: The absence of clinical sign improvement within 30 minutes and for up to a maximum of 6 hours can be considered as failure of the high-flow nasal cannula therapy. If this time elapses with no improvements, escalating to another type of ventilatory support should be considered.

High-flow nasal cannula failure: can clinical outcomes determine early interruption? / Falha da cânula nasal de alto fluxo: os desfechos clínicos podem determinar a interrupção precoce?

ABSTRACT Objective: To evaluate the evolution of clinical outcomes in children with bronchiolitis who used a high-flow nasal cannula, and to determine after long of non-clinical improvement the therapy should be discontinued, and treatment should be escalated to other forms of ventilatory support. Methods: An observational retrospective study of infants with bronchiolitis who used a high-flow nasal cannula. Patients were divided into two study groups according to success or failure of high-flow nasal cannula therapy, namely the Success Group and the Failure Group. The main demographics and clinical variables were assessed 30 minutes and 6 hours after initiating therapy until removal of the high-flow nasal cannula. Results: A total of 83 children were studied and 18 children (21.7%) failed therapy. Among subjects with successful therapy, a significant decrease in respiratory rate (p<0.001), and a significant increase in peripheral oxygen saturation (p<0.001) were observed within 30 minutes. The Success Group was significantly different from the Failure Group after 6 hours, for both respiratory rate (p<0.01) and peripheral oxygen saturation (p<0.01). Conclusion: The absence of clinical sign improvement within 30 minutes and for up to a maximum of 6 hours can be considered as failure of the high-flow nasal cannula therapy. If this time elapses with no improvements, escalating to another type of ventilatory support should be considered.

RESUMO Objetivo: Avaliar a evolução de desfechos clínicos em crianças com bronquiolite que utilizaram cânula nasal de alto fluxo, e determinar com quanto tempo de não melhora clínica a terapia deve ser interrompida para escalonamento do tratamento para outras formas de suporte ventilatório. Métodos: Estudo observacional retrospectivo, de lactentes com bronquiolite que utilizaram cânula nasal de alto fluxo. Os pacientes foram divididos em dois grupos de estudo, de acordo com o sucesso ou não da terapêutica com cânula nasal de alto fluxo, nomeados Grupo Sucesso e Grupo Falha. Foram analisadas as principais características demográficas e variáveis clínicas, tendo sido avaliadas 30 minutos e 6 horas após o início do tratamento até a retirada da cânula nasal de alto fluxo. Resultados: Foram estudados 83 crianças; destas, 18 crianças (21,7%) falharam. Entre os pacientes que tiveram sucesso na terapia, observou-se diminuição significativa da frequência respiratória (p<0,001), e também aumento significativo da saturação de oxigênio (p<0,001) já nos primeiros 30 minutos. O Grupo Sucesso foi significativamente diferente do Grupo Falha a partir de 6 horas, tanto para frequência respiratória (p<0,01), quanto para saturação de oxigênio (p<0,01). Conclusão: Na ausência de melhora dos sinais clínicos, a falha da terapia com cânula nasal de alto fluxo já pode ser considerada a partir de 30 minutos e, no máximo, em até 6 horas após o início da terapia. Após esse período sem melhora, o escalonamento para outro tipo de suporte ventilatório deve ser avaliado.