1. Purpose Prone position is a non-invasive way of increasing oxygenation in infants and children hospitalised with acute respiratory distress (RDS) [1]. In particular when consolidated areas are present in RDS, they are usually in the declivous regions of the lung and recruiting them by changing the patient’s position (in particular from supine to prone position) may be useful. The aim of this therapeutic approach treating RDS is “to open a closed lung” [2, 3]. Accidental tracheal extubation or withdrawal of vascular catheter may occur during pronation manoeuvre (PM) and there is a well known association between prone position and sudden infant death syndrome (SIDS) [1]. For these reasons an evaluation of the effectiveness of PM is necessary before its employed. We analysed lung echography (LE) efficacy and usefulness in the evaluation of PM in RDS. 2. Methods and Materials A group of 65 premature neonates, suffering from RDS, treated in neonatal intensive care unit, have been preliminarly studied with direct thorax radiogram and LE. 15 (9 males, 7 females) of these patients, which presented significant consolidation areas (maximum diameter more than 2,5 cm) underwent PM: the procedure efficacy was evaluated echographically. A portable echograph: MyLab 25®, Esaote Spa, Florence, with a 7,5- 13 MHz linear probe was used. Our approach was transthoracic by using longitudinal, transversal and coronal scans. Echographic evaluation of PM was compared with variations in arterial partial pressure of oxygen (PaO2) and of carbon dioxide (PaCO2) and to the differnt radiographic aspect of the thorax before and after PM. 3. Results All the 65 infants we preliminarly studied showed a diffused echographic B-line pattern without spared areas and pleural iperhechoic line irregularly thickened wich permitted to confirm clinical diagnoses. Always minimal, subpleural areas of parenchymal consolidation were present but only in 15 patients we found significant consolidation areas (maximum diameter more than 2,5 cm). In 11 patients LE showed complete recruitment of consolidated areas. In 2 pts affected by 2 areas of basal consolidation we had only a partial recruitment. In 2 pts we didn’t have neither echographic signs of recruitment, nor changes in PaO2 and PaCO2. In the patients in which PM was effective, we made a comparison between LE and increase in arterial partial pressure of oxygen (PaO2) or of carbon dioxide (PaCO2) and we found a correlation between echographic changes and improvement in the partial pressures of the 2 gasses. Furthermore we found some correlations between ultrasound changes and different radiological aspect before and after PM. 4. Conclusion LE allows an accurate evaluation of results of pronation manoevre. Unfortunately echography provides a limited field of view, so it may be difficult to measure the real extension of the consolidations. A further limit in this kind of approach may be the fact that only parenchymal abnormalities adjacent to the visceral pleura are evaluable with ultrasounds. When PM repetition is necessary, the study should be performed by the same operator because there is a well-known operator-dependance in echotomography. This is a preliminary study and it didn't allow us to determine LE sensitivity in the evaluation of RM, as the gold standard is CT, which cannot be routinely used for obvious ethical reasons. A larger number of patients should be evaluated in order to define the usefulness and the limits of the methods employed. This particular application of LE is quite easy to learn but, in our opinion, a good knowledge of lung sonography is advisable. REFERENCES [1] Wells DA, Gillies D, Fitzgerald DA. Positioning for acute respiratory distress in hospitalised infants and children. Cochrane Database Syst Rev. 2005:18; 2. [2] Barbas CS, de Matos GF, Pincelli MP (2005) Mechanical ventilation in acute respiratory failure: recruitment and high positive end-expiratory pressure are necessary. Curr Opin Crit Care. 11(1):18-28. [3] Papadakos PJ, Lachmann B. (2007) The open lung concept of mechanical ventilation: the role of recruitment and stabilization. Crit Care Clin. 23(2):241-250.
Ecographic evaluation of pronation manoeuvre efficacy in neonatal respiratory distress syndrome: Report of 15 cases
FELETTI FPrimo
Project Administration
;
2009
Abstract
1. Purpose Prone position is a non-invasive way of increasing oxygenation in infants and children hospitalised with acute respiratory distress (RDS) [1]. In particular when consolidated areas are present in RDS, they are usually in the declivous regions of the lung and recruiting them by changing the patient’s position (in particular from supine to prone position) may be useful. The aim of this therapeutic approach treating RDS is “to open a closed lung” [2, 3]. Accidental tracheal extubation or withdrawal of vascular catheter may occur during pronation manoeuvre (PM) and there is a well known association between prone position and sudden infant death syndrome (SIDS) [1]. For these reasons an evaluation of the effectiveness of PM is necessary before its employed. We analysed lung echography (LE) efficacy and usefulness in the evaluation of PM in RDS. 2. Methods and Materials A group of 65 premature neonates, suffering from RDS, treated in neonatal intensive care unit, have been preliminarly studied with direct thorax radiogram and LE. 15 (9 males, 7 females) of these patients, which presented significant consolidation areas (maximum diameter more than 2,5 cm) underwent PM: the procedure efficacy was evaluated echographically. A portable echograph: MyLab 25®, Esaote Spa, Florence, with a 7,5- 13 MHz linear probe was used. Our approach was transthoracic by using longitudinal, transversal and coronal scans. Echographic evaluation of PM was compared with variations in arterial partial pressure of oxygen (PaO2) and of carbon dioxide (PaCO2) and to the differnt radiographic aspect of the thorax before and after PM. 3. Results All the 65 infants we preliminarly studied showed a diffused echographic B-line pattern without spared areas and pleural iperhechoic line irregularly thickened wich permitted to confirm clinical diagnoses. Always minimal, subpleural areas of parenchymal consolidation were present but only in 15 patients we found significant consolidation areas (maximum diameter more than 2,5 cm). In 11 patients LE showed complete recruitment of consolidated areas. In 2 pts affected by 2 areas of basal consolidation we had only a partial recruitment. In 2 pts we didn’t have neither echographic signs of recruitment, nor changes in PaO2 and PaCO2. In the patients in which PM was effective, we made a comparison between LE and increase in arterial partial pressure of oxygen (PaO2) or of carbon dioxide (PaCO2) and we found a correlation between echographic changes and improvement in the partial pressures of the 2 gasses. Furthermore we found some correlations between ultrasound changes and different radiological aspect before and after PM. 4. Conclusion LE allows an accurate evaluation of results of pronation manoevre. Unfortunately echography provides a limited field of view, so it may be difficult to measure the real extension of the consolidations. A further limit in this kind of approach may be the fact that only parenchymal abnormalities adjacent to the visceral pleura are evaluable with ultrasounds. When PM repetition is necessary, the study should be performed by the same operator because there is a well-known operator-dependance in echotomography. This is a preliminary study and it didn't allow us to determine LE sensitivity in the evaluation of RM, as the gold standard is CT, which cannot be routinely used for obvious ethical reasons. A larger number of patients should be evaluated in order to define the usefulness and the limits of the methods employed. This particular application of LE is quite easy to learn but, in our opinion, a good knowledge of lung sonography is advisable. REFERENCES [1] Wells DA, Gillies D, Fitzgerald DA. Positioning for acute respiratory distress in hospitalised infants and children. Cochrane Database Syst Rev. 2005:18; 2. [2] Barbas CS, de Matos GF, Pincelli MP (2005) Mechanical ventilation in acute respiratory failure: recruitment and high positive end-expiratory pressure are necessary. Curr Opin Crit Care. 11(1):18-28. [3] Papadakos PJ, Lachmann B. (2007) The open lung concept of mechanical ventilation: the role of recruitment and stabilization. Crit Care Clin. 23(2):241-250.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
