Change of respiratory mechanics parameters and pulmonary arterial pressure in perinatal neonate with pulmonary and extrapulmonary acute respiratory distress syndrome

Abstract

Objective To explore the changes and significance of respiratory mechanics parameters and pulmonary arterial pressure (PAP) of prenatal stage neonates with pulmonary acute respiratory distress syndrome (ARDSp) or extrapulmonary acute respiratory distress syndrome (ARDSexp). Methods From May 2015 to August 2017, a total of 78 prenatal stage neonates with acute respiratory distress syndrome (ARDS) who were admitted to department of Neonatology of the Affiliated Yancheng Hospital of Southeast University Medical College, were chosen as research subjects. According to different causes of ARDS, 41 neonates with ARDSp were including into ARDSp group and 37 neonates with ARDSexp were including into ARDSexp group. And from department of Obstetrics in same hospital during the same period, a total of 40 healthy neonates with same age were included into control group. The severity of 78 ARDS neonates were determined as mild, moderate and severe according to oxygenation index (OI). The independent-samples t test, variance analysis and chi-square test were used to compare the following measurement data or numeration data. ①Comparasion of clinical data, OI and respiratory mechanics parameters between ARDSp group and ARDSexp group; PAP values of different severity degrees of ARDS neonates in each group or between two groups. ②PAP values of ARDSp and ARDSexp groups at 0, 24, 48, 72, 96 h after breath support, and pre-extubation time points, also PAP values of control group at corresponding hourly ages. Pearson correlation analysis was used to analyze the correlation between OI and PAP of 78 neonates with ARDS. This study met the requirements of World Medical Association Declaration of Helsinki revised in 2013. Results ①Perinatal stage neonates′gestational age, birth weight, usage rate of pulmonary surfactant (PS), incidence rate of persistent pulmonary hypertension of newborn (PPHN) and mortality rate of ARDSexp group [(37.5±1.7) gestational weeks, (2 548±465) g, 13.5%, 2.7%, 2.7%] were all lower than those of ADRSp group [(38.9±1.7) gestational weeks, (3 188±513) g, 78.0%, 24.4%, 19.5%], while the success rate of continuous positive airway pressure (CPAP) of ARDSexp group (13.5%) was higher than that of ARDSp group (0), and all the differences were statistically significant (t=3.632, P<0.001; t=5.750, P<0.001; χ2=32.491, P<0.001; χ2=7.552, P=0.006; χ2=5.384, P=0.020; χ2=5.920, P=0.015). ②A total of 73 ARDS neonates accepted invasive mechanical ventilation in this study, and at time point of 24 h, the OI, mean airway pressure (MAP) and airway resistance (Raw) of ARDSexp group [(14.8±4.3), (10.4±2.9) cmH2O, (83.9±18.3) cmH2O/(L·s)] (1 cmH2O=0.098 kPa) were all lower than those of ARDSp group [(18.8±3.2), (15.5±2.4) cmH2O, (115.8±30.7) cmH2O/(L·s)], while compliance of the respiratory system (Crs) of ARDSexp group [(0.39±0.09) mL/(cmH2O·kg)] was higher than that of ARDSp group [(0.26±0.05) mL/(cmH2O·kg)], and all the differences were statistically significant (t=4.561, 8.754, 5.537, 7.713; all P<0.001). ③After 24 h of respiratory support, PAP values of moderate or severe ARDS neonates in ARDSexp group [(54.7±5.9) mmHg, (64.2±4.9) mmHg] (1 mmHg=0.133 kPa) were lower than those in ARDSp group [(62.5±5.4) mmHg, (68.0±6.5) mmHg], respectively, and the differences were statistically significant (t=3.258, 2.148; all P<0.05). In ARDSp group, PAP values of severe ARDS neonates was higher than that of moderate ARDS neonates, and the difference was statistically significant (t=2.424, P=0.021). In ARDSexp group, PAP values of severe ARDS neonates were higher than that of mild [(37.8±6.5) mmHg] and moderate ARDS neonates, respectively, while PAP values of moderate ARDS neonates was higher than that of mild ARDS neonates, and all the differences were statistically significant (t=14.060, 4.891, 5.629; all P<0.001). ④Pearson correlation analysis showed that there was a positive linear correlation between OI and PAP in 78 ARDS neonates (r=0.720, P<0.001). ⑤PAP values of neonates in ARDSp and ARDSexp group after respiratory support of 0, 24, 48, 72, 96 h and pre-extubation were higher than those of neonates at the corresponding hourly age after birth in control group, respectively, and the differences were statistically significant (t=16.920, 21.600, 27.200, 24.440, 21.670, 18.690; t=11.380, 24.680, 37.800, 15.670, 14.460, 18.060; all P<0.001). PAP values of neonates in ARDSexp group after 0, 48, 72, 96 h of respiratory support were lower than those in ARDSp group, but higher than that in ARDSp group after 24 h of respiratory support, and all the differences were statistically significant (t=5.136, 4.829, 8.197, 6.691, 7.483, all P<0.001). Conclusions The PAP of perinatal stage neonates with ARDS increased in varying degrees, and its increased degree was related to the severity of ARDS. The respiratory mechanics paramaters and PAP of ADRSp neonates were different from ADRSexp neonates, PAP can be used as a judgement indicator of the severity and prognosis of ARDS. Key words: Respiratory distress syndrome, newborn; Hypertension, pulmonary; Persistent fetal circulation syndrome; Respiratory mechanics; Perinatology; Lung injury; Infant, newbron