Cerebrospinal fluid lactate dehydrogenase in infants with perinatal asphyxia

Lactate dehydrogenase as an indicator of severe illness in neonatal intensive care patients: a longitudinal cohort study

AIM

Lactate dehydrogenase (LDH) increases in several critical conditions that cause cell damage and could potentially be used for early detection of serious illness in the newborn. Our aim was to investigate the relationship between the early clinical course of NICU infants and LDH in plasma at admission.

METHODS

LDH was measured in a cohort of patients consecutively admitted to a major NICU in Hanoi. The infants were classified as 'obviously needing intensive care during the first week' (n = 83) or 'not receiving intensive care measures during the first week' (n = 260) by a senior neonatologist blinded to the LDH and lactate activity.

RESULTS

LDH differed significantly between the groups in infants born after 32 gestational weeks. LDH differed with the vitality of the patient (F = 26.25, p < 0.0001) at admittance and correlated with lactate (R = 0.496, p < 0.0001). Also, the predictive value for obvious need of intensive care was higher for LDH than for lactate assessed by area under the curve calculated with ROC-curves [0.82 (0.77-0.88) vs. 0.67 (0.60-0.75)].

CONCLUSION

There is a strong relationship between bad clinical condition of infants during first week of life and elevated plasma LDH. The results suggest that LDH might be a valuable support in decision making in the neonatal period.

Cerebrospinal fluid lactate dehydrogenase isoenzymes in children with bacterial and aseptic meningitis

Differentiation of bacterial from aseptic meningitis may be difficult. Our aim was to determine the pattern of distribution of lactate dehydrogenase (LDH) isoenzymes in the cerebrospinal fluid (CSF) of patients with bacterial and aseptic meningitis. One hundred and fifty-seven patients with suspected meningitis were enrolled in the study. They were divided into 3 groups according to the culture- or bacterial antigen assay-proven diagnosis and CSF findings: bacterial meningitis (n = 31), aseptic meningitis (n = 65), and non-meningitis (n = 61). Total LDH level and percentages of LDH isoenzymes in the CSF were measured in each patient. Each group showed a distinct LDH isoenzyme distribution pattern, with a statistically significant difference among the groups in the percentages of the various isoenzymes. Compared with the non-meningitis group, total LDH activity in the CSF was high in the aseptic meningitis group (49.82+/-35.59 U/L, P < 0.001) and exaggerated in the bacterial meningitis group (944.53+/-112.3 U/L, P < 0.001). Low LDH-2 levels were unique to bacterial meningitis (P < 0.01), whereas high LDH-3 levels were characteristic of aseptic meningitis (P < 0.05). Both groups had low levels of LDH-1 and high levels of LDH-4 and LDH-5. In conclusion, the LDH isoenzyme pattern may be of clinical diagnostic value in meningitis, particularly when culture results are pending.

High-dose phenobarbital therapy in term newborn infants with severe perinatal asphyxia: a randomized, prospective study with three-year follow-up

OBJECTIVE

To determine whether 40 mg/kg phenobarbital given to term infants with severe asphyxia would result in a lower incidence of seizures in the newborn period and an improved neurologic outcome.

METHODS

We conducted a randomized, controlled, prospective study. Entry criteria included (1) an initial arterial pH less than or equal to 7.0 with a base deficit 15 mEq/L or more, (2) Apgar score less than or equal to 3 at 5 minutes of age, or (3) failure to initiate spontaneous respiration by 10 minutes of age. Sample size was calculated to detect a 50% reduction in the incidence of neonatal seizures.

RESULTS

No differences were present between treatment and control groups with respect to severity of asphyxia assessed by initial arterial pH, base excess, cerebrospinal fluid lactate dehydrogenase concentration or detection of CSF creatine kinase of its BB isoenzyme. Seizures occurred in 9 of 15 infants in the treatment group and 14 of 16 infants in the control group (p = 0.11). No adverse effects were observed from phenobarbital on heart rate, respiratory rate, blood pressure, or arterial blood gas values. Three-year follow-up revealed normal outcome in 11 of 15 infants in the treatment group and 3 of 16 in the control group (p = 0.003).

CONCLUSION

Phenobarbital, when administered in a dose of 40 mg/kg intravenously over 1 hour in term, severely asphyxiated newborn infants appeared to be safe and was associated with a 27% reduction in the incidence of seizures and a significant improvement in neurologic outcome at 3 years of age.

Effect of hyperventilation on oxygenation of the brain cortex of neonates

A new phosphorescence imaging method (Rumsey et al, Science (1988) 1649) has been used to continuously monitor the oxygen pressure in the blood of the cerebral cortex of newborn pigs. The animals' blood pressure was continuously measured and PaCO2, PaO2 and arterial blood pH were measured periodically. The oxygen pressure in the blood was quantitatively determined for regions of about 100 um square within the image (from a total field of about 3 mm diameter). It was observed that during hyperventilation, which lowered PaCO2 and increased pH of the blood, oxygen pressure decreased in proportion to the decrease in PaCO2. For example, hyperventilation which decreased PaCO2 from its normal value of 40 Torr to 10 Torr caused a rapid (within 5 minutes) decrease in oxygen pressure in the blood of capillaries and veins to approximately 1/4 of normal.

Serum CPK-BB isoenzyme in the assessment of brain damage in asphyctic term infants

Serum creatine phosphokinase-BB activities were measured at 4 and at 10 hours of life in 33 asphyctic full-term infants. The infants were followed for a mean period of 16 months. Enzyme activities at 4 hours of life were significantly higher in those neonates who died of severe hypoxic-ischemic encephalopathy or developed neurological sequelae than in those who did not present neurological abnormalities during the follow-up time. The specificity of the enzyme assay in order to predict the neurological outcome was inferior to that of cranial computed tomography or a combined clinical-electroencephalographic evaluation. It appears that the presence of elevated serum creatine phosphokinase-BB activity can be a sensitive indicator of conspicuous brain damage, but it is of limited value to predict the neurological outcome after neonatal asphyxia.

Time study of macroscopic identification of experimental cerebral infarction in rat

Cerebral infarctions were induced in rats by injection of Sephadex G-200 into the internal carotid artery. Unfixed slices of brain were stained with nitro blue tetrazolium (nitro-BT). Tissue dehydrogenase in normal regions reacts with this chemical and changes from a pale yellow color to dark blue consequent to formation of formazan. However, the color changes do not develop in infarcted tissue as there is depletion of tissue dehydrogenase in these regions. Ischemic lesions are identifiable by this method in over half the brain 2 to 4 hours after the embolization, but are seen in all brains 6 hours or more following the embolization. The procedure is simple, requires 30 minutes, and is useful for identification of small or acute cerebral infarction.

LDH isoenzymes in CSF in the diagnosis of neonatal brain damage

Lactate dehydrogenase isoenzymes in cerebrospinal fluid were measured during the first 24 h of life in 25 asphyctic neonates. The infants were subjected to clinical and developmental examinations for a mean follow-up period of 15.2 months. The mean values for cerebrospinal LDH2(MH3) and LDH3(M2H2) isoenzymes were significantly higher in asphyctic infants who died from hypoxic-ischemic encephalopathy or who survived but suffered neurologic sequelae, than they were in those asphyctic infants who survived and were normal in the follow-up studies. Therefore, the authors conclude that the lactate dehydrogenase isoenzyme pattern in cerebrospinal fluid may be of value when assessing anoxic brain damage.

Enzyme studies and neonatal brain damage

The authors report a double-blind study of 57 full-term newborn infants prospectively subjected to clinical, electroencephalographical, blood and cerebrospinal fluid, and developmental examinations. Four enzymatic activities were measured in blood and CSF: aminotransferase (ASAT), creatine kinase (CK), lactate dehydrogenase (LD) and hydroxybutyrate dehydrogenase (HBD). Close relationships of enzymatic levels with psychomotor outcome are reported. In blood, ASAT and CL seemed to be the most important determinations, allowing threshold-values to be suggested. In CSF, LD and HBD were the determinations the most closely related to psychomotor events at age one. This method seems to be of theoretical as well as practical importance in evaluating neonatal brain injury.

CSF levels of lactate and hydroxybutyrate dehydrogenase as indicators of neurological sequelae after neonatal brain damage

A prospective study was made of levels of lactate and hydroxybutyrate dehydrogenase in the blood and cerebrospinal fluid of 57 term neonates, in relation to the time elapsed since delivery, neonatal examinations (Apgar score, neurological symptoms and EEG findings) and psychomotor outcome at one year of age. Serum determinations revealed no significant relationship with clinical assessments. CSF measurements showed significant differences near to the time of delivery between the normal and handicapped groups at age one, which supports the hypothesis of a causal link between neonatal brain damage and CSF enzyme levels.