Association of blood gas pH with clinical outcomes in periviable extremely preterm infant within one week after birth
10.3760/cma.j.cn113903-20240507-00331
- VernacularTitle:生存极限早产儿生后1周内血气pH值与临床结局的关系
- Author:
Chun CHEN
1
;
Hongyan SUN
1
;
Qingling XU
1
;
Chuanzhong YANG
1
Author Information
1. 南方医科大学附属深圳妇幼保健院新生儿科，深圳 518028
- Publication Type:Journal Article
- Keywords:
Periviable;
Premature infants;
Intensive care unit;
Blood gas parameters
- From:
Chinese Journal of Perinatal Medicine
2025;28(5):389-394
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To investigate the association between blood pH measured by blood gas analysis during the first postnatal week and mortality in periviable extremely preterm infant (PEPI).Methods:This retrospective study analyzed 48 PEPIs (gestational age<24 weeks) admitted to the neonatal intensive care unit of Shenzhen Maternity and Child Healthcare Hospital, Southern Medical University between January 2021 and December 2023. According to the clinical outcomes during hospitalization, they were divided into two groups: death group ( n=12, including deaths despite active treatment and deaths due to treatment withdrawal) and survival group ( n=36, including cured and improved cases). Blood gas pH and base excess (BE) values during the first week were collected. Mann-Whitney U test and Chi-square test (or Fisher exact test) were used to compare maternal perinatal conditions and neonatal blood pH values between the two groups. The percentiles ( P3 and P90) of blood pH and BE values were described for the survival group by age. Results:(1) Among the 48 PEPIs, four were born at 21 weeks, 11 at 22 weeks, and 33 at 23 weeks of gestation. The clinical outcomes showed a cure rate of 60.4% (29/48), improvement rate of 14.6% (7/48), mortality due to poor prognosis with treatment withdrawal of 8.3% (4/48), and mortality under active treatment of 16.7% (8/48). (2) There was statistically significant difference in the death after treatment withdrawal among the PEPIs born at 21, 22, and 23 weeks of gestation [1/4, 2/11, and 3.0% (1/33); χ2=7.41, P=0.025]. The death group had higher proportions of infants with Apgar score≤3 at 1, 5, or 10 min after birth as compared with the survival group [7/12 vs. 25.0% (9/36), χ 2=4.50; 7/12 vs.16.7% (6/36), χ 2=7.91; 5/12 vs. 5.6% (2/36), χ 2=9.42; all P<0.05]. (3) The median blood pH values in the death group were lower than those in the survival group at 1-4, and 6 d after birth [7.13 (7.06-7.24) vs. 7.25 (7.23-7.31), Z=－3.44; 7.03 (7.00-7.18) vs. 7.21 (7.16-7.24), Z=－3.07; 7.02 (7.02-7.11) vs. 7.18 (7.13-7.21), Z=－3.51; 7.14 (7.13-7.20) vs. 7.18 (7.16-7.21), Z=－2.38; 7.15 (7.13-7.19) vs. 7.19 (7.17-7.22), Z=－2.08; all P<0.05].The pH value of the deceased infants rapidly declined within three days after birth, with the median pH values at two days and three days of age both falling below 7.05. In deceased infants due to poor prognosis, the median pH value at 4-7 days of age remained consistently at or below 7.15. In the survivors, the blood pH and BE values decreased after birth and hit the bottom at 3 and 5 days of age, respectively ( P3: pH=7.10, BE=－16.10 mmol/L) before gradual recovery. Conclusions:PEPI tend to present with low blood pH during the first postnatal week. However, excessively low blood pH warrants vigilance against adverse outcomes.
