- Published: March 30, 2011
- DOI: 10.1371/journal.pone.0017893
Abstract
Background
Patients with amyotrophic lateral sclerosis (ALS) suffer from hypoventilation, which can easily worsen during sleep. This study evaluated the efficacy of capnography monitoring in patients with ALS for assessing nocturnal hypoventilation and predicting good compliance with subsequent noninvasive ventilation (NIV) treatment.
Methods
Nocturnal monitoring and brief wake screening by capnography/pulse oximetry, functional scores, and other respiratory signs were assessed in 26 patients with ALS. Twenty-one of these patients were treated with NIV and had their treatment compliance evaluated.
Results
Nocturnal capnography values were reliable and strongly correlated with the patients' respiratory symptoms (R2 = 0.211–0.305, p = 0.004–0.021). The duration of nocturnal hypercapnea obtained by capnography exhibited a significant predictive power for good compliance with subsequent NIV treatment, with an area-under-the-curve value of 0.846 (p = 0.018). In contrast, no significant predictive values for nocturnal pulse oximetry or functional scores for nocturnal hypoventilation were found. Brief waking supine capnography was also useful as a screening tool before routine nocturnal capnography monitoring.
Conclusion
Capnography is an efficient tool for assessing nocturnal hypoventilation and predicting good compliance with subsequent NIV treatment of ALS patients, and may prove useful as an adjunctive tool for assessing the need for NIV treatment in these patients.
Fonte: http://www.plosone.org/article/info:doi/10.1371/journal.pone.0017893
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Nota do Blog:
Dra Heloisa Glass, Por favor, nos
explique as diferenças entre a Capnografia, Polissonografia e a Prova de Função
Pulmonar no diagnostico e avaliação da funçaão respiratoria do pac de ELA?
A publicação fala
justamente sobre isso. Vamos simplificar. Quando respiramos colocamos ar para
dentro e para fora dos pulmões (isso é medido nas provas de função pulmonar).
Nos pulmões o ar novo leva oxigênio e é praticamente livre de gás carbônico.
Os pulmões pegam o oxigênio e colocam o gás carbônico para fora. Assim, no ar
que expiramos haverá gás carbônico (isso é medido na capnografia). No sangue
oxigênio (medimos indiretamente com o oxímetro de pulso, aquele aparelhinho que
parece o dedo do ET). Esse trabalho comparou esses exames, e também sintomas. A
conclusão do trabalho é que o exame que melhor prevê o paciente que realmente
precisa de BiPAP é a capnografia.
Drª Heloisa Glass
(https://www.facebook.com/Sonoedpochranecrnmdf?fref=ts)