Methods
This prospective study included a total of 102 cases, comprising 51
infants admitted to a tertiary level Neonatal Intensive Care Unit with a
diagnosis of NE and treated with hypothermia between January 2019 and
June 2020, and a control group of 51 healthy newborns. Before the study,
written informed consent was obtained from the parents of the patients
who participated in the research. Approval for the study was granted by
the Ethics Committee of Harran University Medical Faculty (Approval
date: 07.01.2019, Session 1, Number: 19.01.03). All procedures were
applied in compliance with the Helsinki Declaration.
Inclusion Criteria: All cases included in the perinatal
asphyxia group were admitted to our unit for the application of
therapeutic hypothermia treatment. Therapeutic hypothermia was
administered to patients born at ≥36 weeks, aged ≤6 hours, had cord
blood or blood gas taken within the first hour after birth showing a pH
value of ≤7.00 and/or with base deficit ≥16 mmol/L, had a 10-minute
Apgar score of <5, had an ongoing need for resuscitation and
showed signs of medium or heavy encephalopathy in the clinical
evaluation. In both the clinical assessment and the follow-up period,
aEEG findings were also taken into account.15,16
Exclusion Criteria: Infants were excluded from the study if
they were aged > 6 hours, were born before the
36th week of pregnancy, weighed under 2000 grams, had
an uncertain diagnosis or the presence of other documented conditions
which could cause neonatal encephalopathy, congenital metabolic
diseases, a diagnosed energy deficiency in the family with a sibling’s
medical history and other accompanying diseases together with early
encephalopathy, who were thought to be unlikely to benefit from the
treatment, had severe or extensive parenchymal cranial hemorrhages,
severe life-threatening coagulopathy, maternal chorioamnionitis,
trisomy’s, multiple organ anomalies, bacterial growth in blood cultures
taken within the first 72 hours of life and/or were suspected of having
early-onset neonatal sepsis.15-16
All patients included in the perinatal asphyxia group received TH
treatment. A total of 51 patients underwent TH with the whole body
cooling system. Therapeutic hypothermia was applied using the Arctic
Sun® 5000 Temperature Management System as servo-controlled whole body
cooling with a rectal temperature probe targeting a rectal temperature
of 33.5°C. After 72 hours of cooling, 7 hours of re-warming was applied
(maximum temperature rise of 0.5 ° C / hour) and the session was
finished when the body temperature reached 36.5°C.
In the control group, blood samples were taken within the first 0-6
hours after birth from healthy, term infants who were given to their
mothers following the birth and whose physical examination showed no
pathological findings. In addition, there were no pathological findings
during pregnancy of the mothers of these babies.
Blood Withdrawal and Analysis: Blood samples of 2mL were taken
from all the cases studied for 0-6 hours postpartum and from cases with
hypothermia diagnosed with NE only at 24 and 72 hours. Whole blood count
analysis was performed on the samples obtained using an automated blood
count device (Abbot Celldyn 3500 Ill, USA). As a result of the complete
blood count analysis, leukocyte, neutrophil, lymphocyte, thrombocyte and
MPV values were obtained.
Data Analysis: Statistical analyses were performed using SPSS
version 24.0 software (SPSS Inc, Chicago, IL, USA). Descriptive
statistics were summarized as number, percentage, mean, and standard
deviation values. Normal distribution of the variables was checked
visually (histogram and probability charts) and using analytical methods
(Kolmogorov-Smirnov test). Data showing normal distribution were
analyzed using the Independent Samples t-test. The analysis of skewed
variables was performed using the Mann Whitney U-test. The repeat
measurements of the perinatal asphyxia groups were compared with the
Paired Samples t-test. Categorical variables were analyzed using the
Pearson Chi-square test. Specificity and sensitivity analysis were
performed by using receiver operating characteristic (ROC) curve
analysis technique. In the ROC analysis, the area under the curve (AUC)
values were studied. A value of p<0.05 was accepted as
statistically significant.