Calcium concentration in hypoxic-ischemic encephalopathy during hypothermia

Serum troponin I: a potential biomarker of hypoxic-ischemic encephalopathy in term newborns

OBJECTIVE

This study was intended to evaluate the predictive values of serum procalcitonin (PCT), lactate, creatine kinase (CK-MB), and troponin I on the diagnosis and staging of neonatal hypoxic-ischemic encephalopathy (HIE).

MATERIALS AND METHODS

We retrospectively retrieved data from electronic medical records at our children's hospital, and we included all term newborns admitted between December 2018 and June 2020 with features of perinatal asphyxia. Receiver operating characteristic (ROC) curve and area under the curve (AUC) were used to measure and evaluate the predictive values of biomarkers. p values < 0.05 were set as statistical significance.

RESULTS

A total of 201 neonates were included. They were grouped as control (n = 40), mild HIE (n = 105), moderate HIE (n = 36), and severe HIE (n = 20). Serum lactate, PCT, CK-MB, and troponin I levels in severe hypoxic-ischemic brain injury group were significantly higher than those in mild to moderate hypoxic-ischemic brain injury group and control group (p < 0.05). Based on ROC and AUC analysis, troponin I showed highest predictive ability with AUC of 0.904, and sensitivity and specificity of 95.00% and 87.50% respectively.

CONCLUSION

Serum troponin I has a good predictive value for neonatal hypoxic-ischemic encephalopathy after perinatal asphyxia.

Tubular calcium, magnesium, and phosphate excretion during therapeutic hypothermia for neonatal hypoxic-ischemic encephalopathy: A prospective study

OBJECTIVES

Hypocalcemia, hypomagnesemia, and hyperphosphatemia are common electrolyte disturbances in perinatal asphyxia (PA). Different reasons have been proposed for these electrolyte disturbances. This study investigated the effect of the urinary excretion of calcium (Ca), magnesium (Mg), and phosphorus (P) on the serum levels of these substances in babies who were treated using therapeutic hypothermia for hypoxic ischemic encephalopathy (HIE) caused by PA. This study sheds light on the pathophysiology that may cause changes in the serum values of these electrolytes.

METHODS

This study included 21 healthy newborns (control group) and 38 patients (HIE group) who had undergone therapeutic hypothermia due to HIE. Only infants with a gestational age of 36 weeks and above and a birth weight of 2000 g and above were evaluated. The urine and serum Ca, Mg, P, and creatinine levels of all infants were evaluated at 24, 48, and 72 h.

RESULTS

The lower serum Ca value and the higher serum P value of the HIE group were found to be statistically significant compared to the control group (p<0.05). There was no significant difference in serum Mg values between the groups. However, hypomagnesemia was detected in five patients from the HIE group. The urine excretion of FeCa and FeMg at 24 h, and FeP excretion at 48 and 72 h were found to be significantly higher in the HIE group compared to the control group.

CONCLUSIONS

This study determined that the urinary excretion of Ca, Mg, and P has an effect on the serum Ca, Mg, and P levels of infants with HIE.

Neurological Prognostic Value of Adjusted Ca2+ Concentration in Adult Patients with Out-of-Hospital Cardiac Arrest

Many patients are transferred to hospital due to out-of-hospital cardiac arrest (OHCA), and, unfortunately, most suffer from cerebral damage. Currently, it is difficult to predict the recovery of neurological function after return of spontaneous circulation (ROSC) in the acute phase. Increased intracellular Ca²⁺ induces cell death in the acute phase. Accordingly, we predicted that serum adjusted Ca²⁺ will decrease following Ca²⁺ influx into cells. Consequently, serum adjusted Ca²⁺ in the acute phase may be able to predict recovery of neurological function in patients with ROSC from OHCA. This is a retrospective and observational study from 2 centers. A total of 190 consecutive patients with ROSC from OHCA were recruited, with 33 patients meeting the inclusion criteria. The relationship between serum adjusted Ca²⁺ within 48 hours after ROSC and neurological function at discharge (as evaluated by the Glasgow-Pittsburgh cerebral performance category) was examined. Serum adjusted Ca²⁺ was measured every 4 hours within a 48-hour period after ROSC. There were no significant differences in hemodynamical state and laboratory data between the 2 groups. However, lowest serum adjusted Ca²⁺ within 48 hours after ROSC was significantly lower in the poor neurological outcome group (0.96 ± 0.06 versus 1.02 ± 0.06 mmol/L, P = 0.011). Thus, lowest serum adjusted Ca²⁺ within 48 hours after ROSC may be a predictive factor for recovery of neurological function at discharge in patients with ROSC from OHCA.

A novel scoring system to predict the outcomes of adult patients with hypoxic-ischemic encephalopathy

BACKGROUND

Adult patients with hypoxic-ischemic encephalopathy (HIE) often incur large costs, but their outcomes are poor. Currently, there is lack of a comprehensive quantitative approach to predict patient prognoses.

METHODS

A total of 73 adult patients with HIE participated in this prospective, observational study. Clinical assessments, laboratory tests, and electrophysiological examinations were conducted within 3 days after HIE occurred. Logistic regression model was used to identify independent factors associated with patient outcomes.

RESULTS

After a 6-month follow-up, 44 (61.1%) patients survived, 28 (38.9%) patients died, and one patient was lost to follow-up. The level of blood calcium and lactate, the presence of electroencephalography reactivity, and Glasgow Coma Scale (GCS) score were significantly associated with the patient's outcome. Based on the regression coefficients from logistic regression analysis, we constructed a scoring system (CEGL; C: calcium, E: EEG reactivity, G: GCS, L: lactate) to predict the possibility of a patient's death. The area under the receiver operating characteristic curve was 0.91 (P < 0.001, 95% CI [0.87-0.95]) with a specificity of 97.7% and a positive predictive value of 97.4%.

CONCLUSION

CEGL score can provide clinicians useful information for assessment of patient prognosis within 6 months after HIE.

Serum calcium concentrations and incidence of hypocalcemia in infants with moderate or severe hypoxic-ischemic encephalopathy: Effect of therapeutic hypothermia

BACKGROUND

Hypocalcemia is a common morbidity in asphyxiated infants. Therapeutic hypothermia (TH), the standard of care for infants with moderate and severe hypoxic-ischemic encephalopathy (HIE), promotes neuroprotection by several mechanisms including a decrease in intracellular calcium (Ca(2+)) influx which may improve serum Ca(2+) levels and homeostasis.

AIMS

To evaluate the impact of TH on Ca(2+) homeostasis.

STUDY DESIGN

Historical, retrospective cohort analysis.

SUBJECTS

Infants with moderate or severe HIE admitted to the hospital with≤24hours of age, gestational age≥36weeks, and birth weight ≥1800g, before (pre-TH) and after (post-TH) TH was implemented.

OUTCOME MEASURES

Minimum and maximum serum levels of ionized Ca(2+) (iCa(2+)) and magnesium (Mg), Ca(2+) and Mg intakes, and incidence of hypo/hypercalcemia during the first week of life.

RESULTS

A total of 67 infants were included: 29 pre-TH and 38 post-TH. Minimum iCa(2+)levels were significantly lower in the pre-TH group; some infants required Ca(2+) boluses infusions. In the post-TH group, a significantly lower intake of Ca(2+) was necessary to maintain normal Ca(2+) levels and no infant required boluses. The incidence of hypocalcemia was higher in the pre-TH group with a statistically significant difference on day 2 of life (18 vs 0%; p=0.01).

CONCLUSIONS

After the implementation of TH, iCa(2+) levels were within normal ranges despite lower Ca(2+) intakes. A lower incidence of hypocalcemia was observed during cooling. Our findings support the hypothesis that TH improves Ca(2+) homeostasis in HIE infants.