[Effect of prone or spine position on mechanically ventilated neonates after cardiac surgery with acute lung injury].
OBJECTIVE
To compare the efficacy and safety ventilated with pressure support ventilation (PSV) or neurally adjusted ventilatory assist (NAVA) in neonates undergoing open-heart surgery with acute lung injury (ALI) in spine and prone positions.


METHODS
Fifteen neonates with a mean age of (15 +/- 9) days and a mean weight of (3.5 +/- 0.6) kg underwent open-heart surgery with ALI from July to December in 2009 were enrolled in this study. After hemodynamic stabilization ventilated with pressure regulated volume control (PRVC-base), all cases were ventilated with PSV and NAVA both in spine (SP) and prone (PP) positions for 60 minutes in a randomized crossover trial respectively. The hemodynamics, blood gas analysis, airway pressure, electrical activity of diaphragm (EAdi) and asynchrony index (AI) during every mode were recorded.


RESULTS
The heart rate, systolic blood pressure and central venous pressure were stable in every mode. The peak inspiratory pressure and mean airway pressure in every mode had no significant difference but were significantly lower than in PRVC-base either in spine or prone position. The respiratory rate in PSV and NAVA with prone position was more rapid than in spine position and in PRVC-base (P < 0.05). But there was no significant difference in minute ventilation (MV) for each mode. The oxygenation index was higher in NAVA or PSV in both positions versus PRVC-base [(200 +/- 60) mm Hg in PRVC-base, (272 +/- 76) mm Hg in PSV-SP, (308 +/- 90) mm Hg in PSV-PP, (347 +/- 84) mm Hg in NAVA-SP and (365 +/- 87) mm Hg in NAVA-PP respectively, P < 0.01]. The oxygenation index was significantly higher in NAVA-PP than in PSV-SP (P < 0.05) while PaCO(2) was in normal range and had no significant difference for any mode. The minimal EAdi in NAVA-PP was significant lower than that in PSV-SP [(0.2 +/- 0.1) microV vs (0.5 +/- 0.2) microV, P < 0.05]. The AI of NAVA either in spine or in prone position was 0. It was significantly lower than that in PSV-SP [(21.5 +/- 4.8)%, P < 0.01] and PSV-PP [(22.4 +/- 3.4)%, P < 0.01].


CONCLUSIONS
Especially in a prone position, NAVA demonstrates a better synchrony in ALI neonates after cardiac surgery. It helps to provide a better oxygenation for the patients.
Zhu
Li-min
LM
Department of Cardiothoracic Vascular Surgery, Shanghai Children's Medical Center, Medical College of Shanghai Jiaotong University, Shanghai 200127, China.
Xu
Zhuo-ming
ZM
Ji
Gang
G
Cai
Xiao-man
XM
Liu
Xin-rong
XR
Zheng
Jing-hao
JH
Zhang
Hai-bo
HB
Shi
Zhen-ying
ZY
Xu
Zhi-wei
ZW
Liu
Jin-fen
JF
D055371:Acute Lung Injury / Q000209:etiology / Q000628:therapy*; D006348:Cardiac Surgical Procedures / Q000009:adverse effects; D018592:Cross-Over Studies; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D016684:Prone Position; D012121:Respiration, Artificial / Q000379:methods*