FIRST-line support for Assistance in Breathing in Children (FIRST-ABC): a multicentre pilot randomised controlled trial of high-flow nasal cannula therapy versus continuous positive airway pressure in paediatric critical care.

BACKGROUND: Although high-flow nasal cannula therapy (HFNC) has become a popular mode of non-invasive respiratory support (NRS) in critically ill children, there are no randomised controlled trials (RCTs) comparing it with continuous positive airway pressure (CPAP). We performed a pilot RCT to explore the feasibility, and inform the design and conduct, of a future large pragmatic RCT comparing HFNC and CPAP in paediatric critical care. METHODS: In this multi-centre pilot RCT, eligible patients were recruited to either Group A (step-up NRS) or Group B (step-down NRS). Participants were randomised (1:1) using sealed opaque envelopes to either CPAP or HFNC as their first-line mode of NRS. Consent was sought after randomisation in emergency situations. The primary study outcomes were related to feasibility (number of eligible patients in each group, proportion of eligible patients randomised, consent rate, and measures of adherence to study algorithms). Data were collected on safety and a range of patient outcomes in order to inform the choice of a primary outcome measure for the future RCT. RESULTS: Overall, 121/254 eligible patients (47.6%) were randomised (Group A 60%, Group B 44.2%) over a 10-month period (recruitment rate for Group A, 1 patient/site/month; Group B, 2.8 patients/site/month). In Group A, consent was obtained in 29/33 parents/guardians approached (87.9%), while in Group B 84/118 consented (71.2%). Intention-to-treat analysis included 113 patients (HFNC 59, CPAP 54). Most reported adverse events were mild/moderate (HFNC 8/59, CPAP 9/54). More patients switched treatment from HFNC to CPAP (Group A: 7/16, 44%; Group B: 9/43, 21%) than from CPAP to HFNC (Group A: 3/13, 23%; Group B: 5/41, 12%). Intubation occurred within 72 h in 15/59 (25.4%) of HFNC patients and 10/54 (18.5%) of CPAP patients (p = 0.38). HFNC patients experienced fewer ventilator-free days at day 28 (Group A: 19.6 vs. 23.5; Group B: 21.8 vs. 22.2). CONCLUSIONS: Our pilot trial confirms that, following minor changes to consent procedures and treatment algorithms, it is feasible to conduct a large national RCT of non-invasive respiratory support in the paediatric critical care setting in both step-up and step-down NRS patients. TRIAL REGISTRATION: clinicaltrials.gov, NCT02612415 . Registered on 23 November 2015.

What on earth is APRV?

Partial ventilatory support modalities are ill defined and different perceptions about these modes might depend on geographic region. Exemplary on two recent publications investigating airway pressure release ventilation (APRV) in an adult ICU population, the question is investigated whether research in ventilation modes can be performed with the current definitions. The lack of precise definitions precludes drawing meaningful conclusions from these studies, as it remains unclear how these patients were actually ventilated and whether or how much spontaneous breathing was factitiously preserved. An argument is made to develop a new taxonomy of ventilation modes.

Aplicação da pressão positiva contínua nas vias aéreas associada à fisioterapia respiratória convencional no pós-operatório de cirurgia cardíaca / Application of continuous positive airway pressure associated with conventional respiratory physical therapy after cardiac surgery

Objetivo: Avaliar a eficácia da pressão positiva contínua nas vias aéreas (CPAP) associada à fisioterapia respiratória convencional na recuperação da funcionalidade pulmonar em pacientes submetidos à cirurgia cardíaca com circulação extracorpórea. Métodos: Estudo descritivo com análise quantitativa dos dados, realizado na Unidade Coronariana Intensiva (UCI) do Hospital Universitário de Santa Maria. Cinco pacientes, idade entre 53 e 79 anos, submetidos à esternotomia para cirurgia cardíaca foram avaliados quanto ao volume corrente, capacidade vital, volume minuto, freqüência respiratória e atelectasia, no pré-operatório, primeiro dia de pós-operatório e alta da UCI. Os dados foram processados e analisados pelo Teste de Wilcoxon. Resultados: Houve aumento gradativo no volume corrente, volume minuto e freqüência respiratória, atingindo na alta da UCI valores superiores aos do pré-operatório. A capacidade vital, que decresceu no primeiro dia de pós-operatório, apresentou recuperação, porém não retornou aos valores iniciais até a alta da unidade. Somente um sujeito apresentou atelectasia. Conclusão: As diferenças não tiveram significância estatística, porém considera-se que tiveram significado clínico. O tamanho da amostra não permitiu concluir sobre a eficácia do uso da CPAP neste grupo, no entanto, percebe-se uma tendência de recuperação mais rápida da função pulmonar entre o pré-operatório e os períodos de pós-operatório.

Objective: To assess the effectiveness of continuous positive airway pressure (CPAP) associated to conventional respiratory physical therapy to recover lung function in patients who underwent cardiac surgery with cardiopulmonary bypass. Methods: Descriptive study with quantitative analysis of data, conducted at Intensive Coronary Care Unit (ICCU) of Santa Maria University Hospital, Santa Maria, RS. Five patients, aged 53-79 years, undergoing sternotomy for cardiac surgery were evaluated in relation to the tidal volume, vital capacity, minute volume, respiratory rate and atelectasis on the preoperative, first day postoperative and discharge of ICCU. Data were processed and analyzed through Wilcoxon Test. Results: There was gradative increase at the tidal volume, minute volume and respiratory rate, reaching higher values at ICCU discharge than in the preoperative. The vital capacity, which decreased in the first day of postoperative, showed recovery, but did not achieve the initial values up to the discharge. It was found only one person with atelectasis. Conclusion: There was no statistical significant difference, but significant clinical outcomes. The size of the sample did not allow to conclude on the effectiveness of the CPAP in this group, however there was a tendency of faster recuperation of lung function between the preoperative and postoperative periods.

Pressão positiva contínua nas vias aéreas: modo ventilatório / Continuous positive airway pressure: mode of ventilation

Objetivo Avaliar se a pressão positiva contínua nas vias aéreas promove alterações fisiológicas nas variáveis respiratórias que a caracterizam como um modo ventilatório e comparálas com a pressão de suporte. Métodos Trata-se de um estudo prospectivo com 39 indivíduos adultos sadios, voluntários, realizado em um hospital universitário terciário. Todos os voluntários foram monitorizados em respiração espontânea com o monitor CO2SMO - Dixtal. Posteriormente, o modo pressão de suporte foi ajustado em 5cmH2O acima da pressão positiva expiratória final (de igual valor). Após sete dias, os indivíduos foram submetidos aos mesmos procedimentos, porém com a aplicação de pressão positiva contínua nas vias aéreas de 7cmH2O. O ventilador utilizado foi da marca Dragër, modelo Savina®. Resultados Dentre as variáveis respiratórias, foram observados aumento nos volumes minuto e minuto alveolar, nos picos de fluxo inspiratório e expiratório e na saturação periférica de oxigênio. O volume corrente foi similar com ambos os modos, porém o gás carbônico expirado foi menor na pressão de suporte, quando comparado com a respiração espontânea. Isto pode ser justificado pelo aumento na freqüência respiratória nesse modo. Conclusão Em voluntários saudáveis, a pressão positiva contínua nas vias aéreas induz a variações fisiológicas similares nos parâmetros respiratórios, tais como a pressão de suporte, quando a pressão média das vias aéreas é correspondente. Se o critério considerado para modalidade ventilatória é a variação no volume corrente e freqüência respiratória, dentre outras variáveis, pode-se concluir que a pressão positiva contínua nas vias aéreas é um tipo de modo ventilatório

Objective The objective of this study was to assess if continuous positive airway pressure promotes physiological changes in the respiratory variables that characterize it as a mode of ventilation and compare it with pressure support ventilation. Methods This is a prospective study with 39 adult, healthy volunteers done in a tertiary university hospital. All volunteers were monitored while breathing spontaneously with the monitor CO2SMO - Dixtal. Later, the pressure support mode was adjusted in 5cmH2O above the positive end-expiratory pressure (of same value). After seven days, the individuals were submitted to the same procedures, however with application of a continuous positive airway pressure of 7cmH2O. The ventilator brand was Dragër, model Savina®. Results The following respiratory variables increased: minute volume, alveolar minute volume, peak inspiratory and expiratory flows and saturation of peripheral oxygen. Tidal volume was similar in both modes but expired carbon dioxide was smaller during pressure support when compared with spontaneous breathing. This may be explained by the increased respiratory rate in this mode. Conclusion In healthy volunteers, continuous positive airway pressure induces similar physiological variations in respiratory parameters, such as pressure support when mean airway pressure corresponds. If the criterion considered for mode of ventilation is variation in tidal volume and respiratory rate among other variables, one can conclude that continuous positive airway pressure is a type of mode of ventilation