Frequência respiratória como preditor de falha de desmame da ventilação mecânica

Emídio Jorge Santos Lima

doi:10.1590/S0034-70942013000100001

Scientific Article

Frequência respiratória como preditor de falha de desmame da ventilação mecânica

Respiratory rate as a predictor of weaning failure from mechanical ventilation

Emídio Jorge Santos Lima

http://dx.doi.org/10.1590/S0034-70942013000100001 Braz J Anesthesiol, vol.63, n1, p.7-12, 2013

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OBJETIVOS E JUSTIFICATIVAS: Não existe um preditor de desmame da ventilação mecânica (VM) ideal. Numa grande metanálise, apesar de limitações metodológicas, a frequência respiratória (FR) foi considerada um preditor promissor. O objetivo deste estudo foi avaliar a FR como um preditor de falha de desmame da VM. MÉTODO: Avaliamos prospectivamente 166 pacientes destinados ao desmame da VM. A FR e outros parâmetros essenciais para desmame foram avaliados numa fase inicial de triagem. Os pacientes que apresentaram na triagem os parâmetros essenciais para desmame foram submetidos ao teste de respiração espontânea. A FR foi comparada com os desfechos: sucesso, falha de desmame ou falha de extubação. RESULTADOS: Sucesso de desmame em 76,5% e falha de desmame em 17,5% dos pacientes. Seis por cento de reintubações. O poder preditivo para falha de desmame da FR, melhor ponto de corte FR > 24 respirações por minuto (rpm), foi: sensibilidade de 100%, especificidade de 85% e acurácia de 88% (curva ROC, p < 0,0001). Dos pacientes com falha de desmame, 100% foram identificados pela FR na fase de triagem (corte FR > 24 rpm). Houve 15% de falsos positivos, sucessos de desmame com FR > 24 rpm. CONCLUSÃO: A FR foi um preditor eficiente de falha de desmame. Encontrou-se como melhor ponto de corte FR > 24 rpm, diferentemente daqueles referidos pela literatura (35 e 38 rpm). Apenas 6% dos pacientes foram reintubados e tanto a FR quanto os outros parâmetros para desmame não tiveram capacidade de identificá-los. © 2013 Sociedade Brasileira de Anestesiologia.

Palavras-chave

DESMAME DO RESPIRADOR, FISIOLOGIA, Respiratória, VENTILAÇÃO

Abstract

BACKGROUND AND OBJECTIVE: There is not an ideal predictor of weaning from mechanical ventilation (MV). In a large meta-analysis, despite methodological limitations, respiratory rate (RR) was considered a promising predictor. The aim of this study was to evaluate RR as a predictor of weaning failure from MV. METHODS: We prospectively evaluated 166 patients scheduled for weaning from MV. RR and other essential criteria for weaning were evaluated at an early stage of screening. Patients who met the essential screening criteria for weaning underwent spontaneous breathing trial. RR was compared with the following outcomes: weaning success/failure or extubation failure. RESULTS: Weaning success was present in 76.5% and weaning failure in 17.5% of patients. There were 6% of reintubations. The predictive power for RR weaning failure, RR best cut-off point > 24 breaths per minute (rpm), was: sensitivity 100%, specificity 85%, and accuracy 88% (ROC curve, p < 0.0001). Of the patients with weaning failure, 100% were identified by RR during screening (RR cut-off > 24 rpm). There were 15% false positives, weaning successes with RR > 24 rpm. CONCLUSION: RR was an effective predictor of weaning failure. The best cut-off point was RR > 24 rpm, which differed from those reported in the literature (35 and 38 rpm). Only 6% of patients were reintubated, but RR or other weaning criteria did not identify them.

Keywords

Respiration, Artificial, Respiratory Rate, Ventilator Weaning

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Frequência respiratória como preditor de falha de desmame da ventilação mecânica

Respiratory rate as a predictor of weaning failure from mechanical ventilation

Emídio Jorge Santos Lima

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