Estimation of patient's inspiratory effort from the electrical activity of the diaphragm.
Crit Care Med
; 41(6): 1483-91, 2013 Jun.
Article
em En
| MEDLINE
| ID: mdl-23478659
ABSTRACT
OBJECTIVES:
To calculate an index (termed Pmusc/Eadi index) relating the pressure generated by the respiratory muscles (Pmusc) to the electrical activity of the diaphragm (Eadi), during assisted mechanical ventilation and to assess if the Pmusc/Eadi index is affected by the type and level of ventilator assistance. The Pmusc/Eadi index was also used to measure the patient's inspiratory effort from Eadi without esophageal pressure.DESIGN:
Crossover study.SETTING:
One general ICU. PATIENTS Ten patients undergoing assisted ventilation. INTERVENTION Pressure support and neurally adjusted ventilator assist delivered, each, at three levels of ventilatory assistance. MEASUREMENT AND MAINRESULTS:
Airways flow and pressure, esophageal pressure, and Eadi were continuously recorded. Sixty tidal volumes for each ventilator settings were analyzed off-line, at three time points during inspiration. For each time point, Pmusc/Eadi index was calculated. Pmusc/Eadi index was also calculated from airway pressure drop during end-expiratory occlusions. Pmusc/Eadi index was very variable among patients, but within one patient it was not affected by type and level of ventilator assistance. Pmusc/Eadi index decreased during the inspiration. Pmusc/Eadi index obtained during an occlusion from airway pressure swing was tightly correlated with that derived from esophageal pressure during tidal ventilation and allowed to estimate pressure time product.CONCLUSIONS:
Pmusc is tightly related to Eadi, by a proportionality coefficient that we termed Pmusc/Eadi index, stable within each patient under different conditions of ventilator assistance. The derivation of the Pmusc/Eadi index from Eadi and airway pressure during an expiratory occlusion enables a continuous estimate of patient's inspiratory effort.
Texto completo:
1
Bases de dados:
MEDLINE
Assunto principal:
Respiração Artificial
/
Diafragma
/
Inalação
Tipo de estudo:
Clinical_trials
Limite:
Adult
/
Aged
/
Aged80
/
Female
/
Humans
/
Male
/
Middle aged
Idioma:
En
Revista:
Crit Care Med
Ano de publicação:
2013
Tipo de documento:
Article
País de afiliação:
Itália