The Influence of High Flow Nasal Cannulae on the Outcomes of Severe Respiratory Disease in Children Admitted to a Regional Hospital in South Africa.

In settings where access to paediatric intensive care unit (PICU) facilities is constrained and transfer capacity is limited, High Flow Nasal Cannulae (HFNC) might fill an important service gap. The aim of this study was to document the effect of HFNC on the outcomes of children admitted with severe respiratory disease at a regional hospital without a PICU in Cape Town, South Africa. It is a 4-year retrospective analysis documenting two periods of 2 years each, one before (2013-15) and one after (2016-18) the initiation of HFNC use. Patients were between the ages of 2 months and 13 years and had been admitted to a paediatric ward. Outcomes were defined by the need for transfer to a tertiary hospital, the need for invasive ventilation and death. There were 90 instances of HFNC use with a significant reduction in the number of children who were transferred (59 vs. 31), invasively ventilated (20 vs. 6, p ≤ 0.01) and who died (3 vs. 0, p = 0.02). Before HFNC implementation, there was also a significantly greater proportion of transferred children who remained on low flow nasal cannulae (15 vs. 2, p ≤ 0.001) at the tertiary hospital. Children who failed HFNC use tended to do this within a day of initiation (Median 11 vs. 60 h for success, p ≤ 0.001). There were no complications related to its use. We believe that in our setting the utilization of HFNC has helped to timeously and accurately identify children needing to be transferred and may mitigate against severe respiratory disease progression.

Eficácia e segurança da oxigenoterapia com cânula nasal de alto fluxo na insuficiência respiratória hipercápnica moderada aguda / Efficacy and safety of high-flow nasal cannula oxygen therapy in moderate acute hypercapnic respiratory failure

RESUMO Objetivo: Avaliar a eficácia e a segurança da oxigenoterapia com uso de cânula nasal de alto fluxo no tratamento da insuficiência respiratória hipercápnica moderada em pacientes que não conseguem tolerar ou têm contraindicações para ventilação mecânica não invasiva. Métodos: Estudo prospectivo observacional de 13 meses envolvendo participantes admitidos a uma unidade de terapia intensiva com insuficiência respiratória hipercápnica ou durante o processo de seu desenvolvimento. Os parâmetros clínicos e de troca gasosa foram registrados em intervalos regulares durante as primeiras 24 horas. Os parâmetros finais foram saturação de oxigênio entre 88 e 92%, juntamente da redução do esforço respiratório (frequência respiratória) e da normalização do pH (≥ 7,35). Os participantes foram considerados não responsivos em caso de necessidade de utilização de suporte ventilatório. Resultados: Trinta participantes foram tratados utilizando oxigenoterapia com cânula nasal de alto fluxo. Esta foi uma população mista com exacerbação de doença pulmonar obstrutiva crônica, edema pulmonar cardiogênico agudo, e insuficiência respiratória aguda pós-operatória e pós-extubação. Observou-se melhora não significante na frequência respiratória (28,0 ± 0,9 versus 24,3 ± 1,5; p = 0,22), que foi aparente nas primeiras 4 horas do tratamento. Ocorreu melhora do pH, embora só se tenham obtido níveis normais após 24 horas de tratamento com cânula nasal de alto fluxo (7,28 ± 0,02 versus 7,37 ± 0,01; p = 0,02). A proporção de não responsivos foi de 13,3% (quatro participantes), dos quais um necessitou e aceitou ventilação mecânica não invasiva, e três necessitaram de intubação. A mortalidade na unidade de terapia intensiva foi de 3,3% (um participante), e um paciente morreu após a alta para a enfermaria (mortalidade hospitalar de 6,6%). Conclusão: O oxigenoterapia com cânula nasal de alto fluxo é eficaz para a insuficiência respiratória hipercápnica moderada e ajuda a normalizar os parâmetros clínicos e de troca gasosa, com taxa aceitável de não responsivos que necessitaram de suporte ventilatório.

ABSTRACT Objective: To assess the efficacy and safety of high-flow nasal cannula oxygen therapy in treating moderate hypercapnic respiratory failure in patients who cannot tolerate or have contraindications to noninvasive mechanical ventilation. Methods: A prospective observational 13-month study involving subjects admitted to an intensive care unit with or developing moderate hypercapnic respiratory failure. Clinical and gas exchange parameters were recorded at regular intervals during the first 24 hours. The endpoints were a oxygen saturation between 88 and 92% along with a reduction in breathing effort (respiratory rate) and pH normalization (≥ 7.35). Subjects were considered nonresponders if they required ventilatory support. Results: Thirty subjects were treated with high-flow nasal cannula oxygen therapy. They consisted of a mixed population with chronic obstructive pulmonary disease exacerbation, acute cardiogenic pulmonary edema, and postoperative and postextubation respiratory failure. A nonsignificant improvement was observed in respiratory rate (28.0 ± 0.9 versus 24.3 ± 1.5, p = 0.22), which was apparent in the first four hours of treatment. The pH improved, although normal levels were only reached after 24 hours on high-flow nasal cannula therapy (7.28 ± 0.02 versus 7.37 ± 0.01, p = 0.02). The rate of nonresponders was 13.3% (4 subjects), of whom one needed and accepted noninvasive mechanical ventilation and three required intubation. Intensive care unit mortality was 3.3% (1 subject), and a patient died after discharge to the ward (hospital mortality of 6.6%). Conclusion: High-flow nasal cannula oxygen therapy is effective for moderate hypercapnic respiratory failure as it helps normalize clinical and gas exchange levels with an acceptable rate of nonresponders who require ventilatory support.