N W Svenningsen

Predictive value of early continuous amplitude integrated EEG recordings on outcome after severe birth asphyxia in full term infants.

The background pattern in single channel amplitude integrated EEG recordings (aEEG) was recorded in 47 infants within the first six hours after birth to see if this could predict outcome after birth asphyxia. The aEEG background pattern during the first six hours of life was continuous and of normal voltage in 26 infants. All these infants survived; 25 were healthy, one had delayed psychomotor development. A continuous but extremely low voltage pattern was present in two infants, both of whom survived with severe handicap. Five infants had flat (mainly isoelectric) tracings during the first six hours of life; four died in the neonatal period, and one survived with severe neurological handicap. Burst-suppression pattern was identified in 14 infants, of whom five died, six survived with severe handicap, and three were healthy at follow up. The type of background pattern recorded within the first six postnatal hours in the aEEG tracings predicted outcome correctly in 43 of 47 (91.5%) infants. Use of aEEG monitoring can predict outcome, with a high degree of accuracy, after birth asphyxia, within the first six hours after birth. The predictive value of a suppression-burst pattern was, however, somewhat lower than the other background patterns. The aEEG seems to be a feasible technique for identifying infants at high risk of subsequent brain damage who might benefit from interventionist treatment after asphyxia.

Monitoring of cerebral function after severe asphyxia in infancy.

Thirty nine infants with severe asphyxia (28 affected perinatally and 11 later) were studied by electrophysiological cerebral function monitoring (CFM) for periods varying from a half to 49 days. Nineteen infants died while still in intensive care and two died later from sequelae. Eighteen survived and were followed up when aged between 8 and 36 months. The initial electroencephalogram (EEG) and the first 12 hours of CFM tracing correlated well. The type of background activity, whether continuous or interrupted, proved to be of high prognostic importance unlike the presence of seizure activity, which bore no distinct correlation to outcome in these severely asphyxiated infants.

Lidocaine for treatment of severe seizures in newborn infants. I. Clinical effects and cerebral electrical activity monitoring

ABSTRACT. The anticonvulsive effect of lidocaine was evaluated in 46 newborn infants with severe, recurrent seizures. Before the lidocaine all infants were being given phenobarbital, and 22 infants were also treated with diazepam. Different dosages of lidocaine were tested. A loading dose of 2 mg/kg followed by i.v. infusion of 6 mg/kg/hour was the most effective dosage and had an immediate anticonvulsive effect in 18 of 25 infants; within 30 min the same effect was attained in another five of the infants, with an overall seizure control in 92% of the sample population. During the lidocaine treatment cerebral electrical activity was followed continuously with a cerebral function monitor (CFM), which also enabled evaluation of the treatment. No serious side effects on blood‐pressure, heart‐rate or cerebral electrical activity were registered. For newborn infants with severe recurrent seizures not responding to other drugs, lidocaine is an effective additional mode of treatment.

Low risk of seizure recurrence after early withdrawal of antiepileptic treatment in the neonatal period.

The risk of seizure recurrence within the first year of life was evaluated in infants with neonatal seizures diagnosed with a combination of clinical signs, amplitude-integrated electroencephalogram (EEG) monitoring, and standard EEG. Fifty eight of 283 (4.5%) neonates in tertiary level neonatal intensive care had seizures. The mortality in the infants with neonatal seizures was 36.2%. In 31 surviving infants antiepileptic treatment was discontinued after one to 65 days (median 4.5 days). Three infants received no antiepileptic treatment, two continued with prophylactic antiepileptic treatment. Seizure recurrence was present in only three cases (8.3%)--one infant receiving prophylaxis, one treated for 65 days, and in one infant treated for six days. Owing to the small number of infants with seizure recurrence, no clinical features could be specifically related to an increased risk of subsequent seizures. When administering antiepileptic treatment, one aim was to abolish both clinical and electrographical seizures. Another goal was to minimise the duration of treatment and to keep the treatment as short as possible. It is suggested that treating neonatal seizures in this way may not only reduce the risk of subsequent seizure recurrence, but may also minimise unnecessary non-specific prophylactic treatment for epilepsy.

EEG depression and germinal layer haemorrhage in the newborn

ABSTRACT. Amplitude integrated EEG (aEEG) recordings from 32 mechanically ventilated infants, gestational age 32 weeks or less, were analysed. All recordings were started within 24 h of birth and continued for at least 50 h. Germinal layer haemorrhage (GLH) was diagnosed by repeated ultrasonography. In six infants neither GLH nor hypocalcaemia were diagnosed; aEEG in these infants rapidly became more active after birth: at 30 h of age continuous background activity was present for more than 20% of the time, and a seizure‐like pattern was exceptional. In seven infants without GLH but with hypocalcaemia and other signs of metabolic derangement, continuous background activity appeared later and seizure‐like activity was frequent. In the infants with GLH, depression of the background activity was apparent. This finding was particularly distinct in the presence of severe haemorrhages. Four infants developed GLH after 30 h of age. All these infants had depressed aEEG beforethe development of GLH, with less than 20% continuous activity at 30 h of age. In ten infants an analysis of the aEEG during the occurrence of GLH was possible. In six of these, cortical electrical activity decreased. Due to the limitation of GLH timing, it was not possible to decide whether this decrease closely preceded or followed GLH. We suggest that GLH primarily occurs in brains with a preceding metabolic and neurophysiologic abnormality, and that further functional deterioration is caused by the most severe haemorrhages.

Lidocaine for treatment of severe seizures in newborn infants. II. Blood concentrations of lidocaine and metabolites during intravenous infusion

The blood concentrations of lidocaine and its main active metabolites, methylethylglycinexylidide (MEGX) and glycinexylidide (GX), were measured in 24 newborn infants during anticonvulsive treatment with an iv infusion of lidocaine. After a bolus dose of 1.5–2.2 mg/kg and continuous infusion of lidocaine (4.7–6.3 mg/kg/h) there was accumulation of the drug and MEGX within 24 h. After termination of the iv infusion, both lidocaine and the metabolites were eliminated within 24–48 h. The anticonvulsive effectiveness–estimated by clinical observation and continuous amplitude integrated EEG monitoring (cerebral function monitor)–was immediate in 15 infants (nine term and six preterm). There was no correlation between blood concentrations of lidocaine and metabolites, and anticonvulsive effect (i. e. good, intermediate or no response). No differences in blood concentrations were found between full‐term and preterm babies, or between infants with or without birth asphyxia. In combination with a fast withdrawal of the drug, few adverse reactions were seen with the dosages used, even though blood concentrations were high. Routine measurements of lidocaine concentrations during anticonvulsive treatment in neonates seem to be of little clinical value. For evaluation of the anticonvulsive effect and for early detection of seizure activity during lidocaine withdrawal, continuous EEG monitoring is preferable.

Long-Distance Transports of Newborn Infants with Congenital Heart Disease

Abstract. Little has been published about specific problems that may occur during long-distance transports of newborn cardiac patients. During a 4-year period after centralization of pediatric heart surgery in Sweden, 286 transports were prospectively investigated. A majority (77.3%) of the transports were carried out by nonspecialized teams. Ten severe adverse events, including the death of 1 infant, occurred during the 286 transports (3.5%). Another infant died later of cerebral complications from hypoxia, rendering a transport-related mortality of 0.7%. Twenty-two infants (7.7%) were severely hypoxic (oxygen saturation ≤65%) at arrival, and 12 of these infants suffered from transposition of the great arteries. During the second 2-year period increased use of intravenous prostaglandin E1 and transportation from tertiary-level units was associated with better transport outcome. During the same time period, overall 30-day postoperative mortality for pediatric cardiac surgery decreased from 4.0% to 1.2% in our hospital. When highly specialized treatment is centralized for quality reasons it is also important that risks associated with transport are considered and that the quality of transport is high. For some cardiac malformations antenatal diagnosis and referral of the mother for delivery to a center with pediatric cardiac surgery would probably further increase the chance of healthy survival in some infants.

Nosocomial Klebsiella pneumoniae Infection: Clinical and Hygienic Measures in a Neonatal Intensive Care Unit

An outbreak in a neonatal intensive care nursery of severe infections caused by Klebsiella pneumoniae type K-17 has been studied. Over a 9-month period 20 epidemiologically linked cases of severe septicemia, meningitis and pneumonia were diagnosed. The specific epidemic strain could be identified. After introduction of a policy of hygienic measures the nosocomial infection could be eradicated although colonization still occurred. Thorough handwashing before and after the nursing care of each infant, individual gowning and disposable gloves in the care of infants below 1 500 g were important. The changing bacterial ecology of a neonatal unit should be followed closely by weekly routine throat cultures as well as by cultures of incubators and ventilation equipment. The present investigation has shown the importance of this procedure, which is mandatory for appropriate choice of antimicrobial agents when treating infections in critically ill or very low birth weight infants in the neonatal intensive care unit. Prophylactic antimicrobial treatment is not indicated. Control of K. pneumoniae nosocomial infections can only be achieved by maintaining a high standard of hygiene in the neonatal care.

Hypoxic-ischaemic encephalopathy is associated with regional changes in cerebral blood flow velocity and alterations in cardiovascular function

Doppler-derived indices of cerebral blood flow velocity (CBFV) and echocardiographic parameters of left ventricular function were measured in 18 patients with hypoxic-ischaemic encephalopathy HIE (group I) and in 28 normal controls (group II). Group-I infants had a subnormal distribution of CBFV values increasing over the first 85 h postnatally. CBFV values were constantly higher in the internal carotid than in the anterior cerebral artery. During the first 24 h postnatally, pulsatility and resistance indices of cerebral blood flow were significantly higher in group-I patients. From 30 to 85 h after birth, resistance indices were lower in group-I infants with severe HIE. Depressed left ventricular function and/or hypotension was documented in 50% of group-I patients.

Cerebral Complications Detected by EEG‐Monitoring during Neonatal Intensive Care

Hellström‐Westas, L., Rosén, I. and Svenningsen, N. W. (Neonatal Intensive Care Unit, Departments of Paediatrics and Clinical Neurophysiology, University Hospital, Lund, Sweden). Cerebral complications detected by EEG‐monitoring during neonatal intensive care. Acta Paediatr Scand Suppl 360: 83, 1989.