Cuidados respiratorios en pacientes con atrofia muscular espinal para evitar el fallo ventilatorio agudo y la traqueostomía: revisión literaria y recomendaciones consensuadas / Respiratory care in patients with spinal muscular atrophy to avoid acute ventilatory failure and tracheostomy: literature review and consensus recommendations

La atrofia muscular espinal (AME) 5q es una de las enfermedades neuromusculares de mayor incidencia en la infancia. Sin embargo, la prevalencia de AME tipo 1, su forma más severa de presentación, es menor debido a muertes prematuras evitables antes de los dos años por insuficiencia ventilatoria subtratada. La irrupción de nuevos tratamientos modificadores de la enfermedad pueden cambiar dramáticamente este pronóstico y es una oportunidad para actualizar el manejo respiratorio, a través de cuidados estandarizados básicos, preferentemente no invasivos, abordando la debilidad de los músculos respiratorios, la insuficiencia tusígena y ventilatoria, con un enfoque preventivo. La siguiente revisión literaria entrega estrategias para evitar la intubación y la traqueostomía usando soporte ventilatorio no invasivo (SVN), reclutamiento de volumen pulmonar (RVP) y facilitación de la tos. Se analizan en detalle los protocolos de extubación en niños con AME tipo 1.

Spinal muscular atrophy (SMA) 5q is one of the neuromuscular diseases with the highest incidence in childhood. Nevertheless, the prevalence of its most severe form SMA1 is lower due to premature preventable deaths before two years of age related to ventilatory insufficiency undertreated. The emergence of new disease-modifying treatments can dramatically change this prognosis and is an opportunity to update respiratory management, through basic standardized care, mostly non-invasive, addressing respiratory muscles pump weakness, cough and ventilatory insufficiency with a preventive approach. This literature review provides consensus recommendations for strategies to avoid intubation and tracheostomy using noninvasive ventilatory support (NVS), lung volume recruitment (LVR), and cough facilitation. Extubation protocols in children with SMA type 1 are analyzed in detail.

Shortening ventilatory support with a protocol based on daily extubation screening and noninvasive ventilation in selected patients

BACKGROUND: Prolonged invasive mechanical ventilation and reintubation are associated with adverse outcomes and increased mortality. Daily screening to identify patients able to breathe without support is recommended to reduce the length of mechanical ventilation. Noninvasive positive-pressure ventilation has been proposed as a technique to shorten the time that patients remain on invasive ventilation. METHODS: We conducted a before-and-after study to evaluate the efficacy of an intervention that combined daily screening with the use of noninvasive ventilation immediately after extubation in selected patients. The population consisted of patients who had been intubated for at least 2 days. RESULTS: The baseline characteristics were similar between the groups. The intervention group had a lower length of invasive ventilation (6 [4;9] vs. 7 [4;11.5] days, p = 0.04) and total (invasive plus noninvasive) ventilator support (7 [4;11] vs. 9 [6;8], p = 0.01). Similar reintubation rates within 72 hours were observed for both groups. In addition, a lower ICU mortality was found in the intervention group (10.8 percent vs. 24.3 percent, p = 0.03), with a higher cumulative survival probability at 60 days (p = 0.05). Multivariate analysis showed that the intervention was an independent factor associated with survival (RR: 2.77; CI 1.14-6.65; p = 0.03), whereas the opposite was found for reintubation at 72 hours (RR: 0.27; CI 0.11-0.65; p = 0.01). CONCLUSION: The intervention reduced the length of invasive ventilation and total ventilatory support without increasing the risk of reintubation and was identified as an independent factor associated with survival.

Acute application of bilevel positive airway pressure influences the cardiac autonomic nervous system.

INTRODUCTION: Noninvasive positive pressure has been used to treat several diseases. However, the physiological response of the cardiac autonomic system during bilevel positive airway pressure (Bilevel) remains unclear. OBJECTIVE: The aim of this study was to evaluate the heart rate variability (HRV) during Bilevel in young healthy subjects. METHODS: Twenty men underwent 10-minute R-R interval recordings during sham ventilation (SV), Bilevel of 8-15 cmH(2)O and Bilevel of 13-20 cmH(2)O. The HRV was analyzed by means of the parallel R-R interval (mean R-Ri), the standard deviation of all R-Ri (SDNN), the root mean square of the squares of the differences between successive R-Ri (rMSSD), the number of successive R-Ri pairs that differ by more than 50 milliseconds (NN50), the percentage of successive R-Ri that differ by more than 50 milliseconds (pNN50), the low frequency (LF), the high frequency (HF) and SD1 and SD2. Additionally, physiological variables, including blood pressure, breathing frequency and end tidal CO(2), were collected. Repeated-measures ANOVA and Pearson correlation were used to assess the differences between the three studied conditions and the relationships between the delta of Bilevel at 13-20 cmH(2)O and sham ventilation of the HRV indexes and the physiological variables, respectively. RESULTS: The R-Ri mean, rMSSD, NN50, pNN50 and SD1 were reduced during Bilevel of 13-20 cmH(2)O as compared to SV. An R-Ri mean reduction was also observed in Bilevel of 13-20 cmH(2)O compared to 8-15 cmH(2)O. Both the R-Ri mean and HF were reduced during Bilevel of 8-15 cmH(2)O as compared to SV, while the LF increased during application of Bilevel of 8-15 cmH(2)O as compared to SV. The delta (between Bilevel at 13-20 cmH(2)O and sham ventilation) of ETCO(2) correlated positively with LF, HF, the LF/HF ratio, SDNN, rMSSD and SD1. Acute application of Bilevel was able to alter the cardiac autonomic nervous system, resulting in a reduction in parasympathetic activity and an increase in sympathetic activity and higher level of positive pressure can cause a greater influence on the cardiovascular and respiratory system.

Ventilação mecânica não-invasiva aplicada em pacientes com insuficiência respiratória aguda após extubação traqueal / Noninvasive positive pressure ventilation in patients with acute respiratory failure after tracheal extubation

JUSTIFICATIVA E OBJETIVOS: A ventilação mecânica não-invasiva (VMNI) tem sido utilizada rotineiramente como método para auxiliar o desmame da ventilação mecânica. Uma das aplicações mais comuns é a sua utilização em pacientes que evoluem com quadro de insuficiência respiratória aguda (IRpA) após a extubação traqueal, embora as evidências científicas para esta indicação ainda sejam controversas. Os objetivos deste estudo foram identificar o número de pacientes que evoluem para IRpA após a extubação, avaliar a eficácia da VMNI para reverter este quadro e promover aumento da taxa de sucesso no desmame da ventilação mecânica. MÉTODO: Foi realizado um estudo prospectivo e transversal. A VMNI foi aplicada nos pacientes que apresentaram IRpA após extubação, independentemente de sua etiologia. A VMNI foi realizada na modalidade pressão de suporte, que foi ajustada para se obter volume-corrente exalado (Vte) de 6 a 8 mL/kg e PEEP e FiO2 ajustados para se obter a SaO2 > 95 por cento. A VMNI foi realizada de forma contínua até cessarem os sinais de IRpA apresentados. O sucesso do desmame e da VMNI foi definido quando os eventos que levaram o paciente à utilização da VMNI fossem revertidos por um período superior a 48 horas de ventilação espontânea, evitando assim a re-intubação. RESULTADOS: Foram incluídos no estudo 103 pacientes. Observou-se que 32 por cento (33) evoluíram com sinais de IRpA após a extubação e foram submetidos a VMNI. O tempo de VMNI utilizado foi 8 ± 5 horas, a PSV utilizada foi de 12 ± 2 cmH2O, PEEP de 7 ± 2 cmH2O, FiO2 de 40 por cento ± 20 por cento, Vte de 462 ± 100 mL, FR de 26 ± 5 rpm. Entre os pacientes submetidos a VMNI (33), 76 por cento (25) cursaram com sucesso e posterior alta do serviço de terapia intensiva e 24 por cento (8) evoluíram com insucesso da VMNI e necessidade de re-intubação. CONCLUSÕES: A VMNI aplicada em pacientes com IRpA após a extubação foi um recurso seguro...

BACKGROUND AND OBJECTIVES: Noninvasive positive pressure ventilation (NPPV) has been routinely used to assist the weaning of the mechanical ventilation. One of the applications most common is in patients who had acute respiratory failure after extubation, even the scientific evidences for this indication still controversy. The aims of this study were to evaluate the index of patients that evolve for respiratory failure after extubation and evaluated the effectiveness of NPPV to avoid the need for reintubation and to promote increase in success index of weaning. METHODS: We conducted a transversal and prospective study. It was applied to NPPV in the patients who presented respiratory failure after extubation, independent of its etiology. NPPV was applied in to pressure support ventilation, with Vte for 6 to 8 mL/kg, PEEP and FiO2 adjusted to reach SaO2 > 95 percent. The NPPV was accomplished of a continuous mould even interrupt the signs of respiratory failure presented initially. The success of weaning and the NPPV was defined when the clinical events were reverted by a period greater than 48 hours in spontaneous breathing, avoid thus reintubation. RESULTS: We included 103 patients. Noted that 32 percent (33) evolved with signals of respiratory failure after extubation and were submitted to NPPV. The time of NPPV was on mean 8 ± 5 hours, PSV of 12 ± 2 cmH2O, PEEP of 7 ± 2 cmH2O, FiO2 of 40 percent ± 20 percent, Vte of 462 ± 100 mL, RR of 26 ± 5 rpm. Among patients who accomplished NPPV (33), 76 percent (25) attended with success and them afterwards let the ICU. Of the patients assigned to NPPV, 24 percent (8) did not tolerate the procedure and were reintubated. CONCLUSIONS: We conclude that NPPV is safe and effective in averting the need for reintubation in patients with respiratory failure after extubation.