Heikki Korvenranta

Growth of 519 Small for Gestational Age Infants during the First Two Years of Life

ABSTRACT. The physical growth of 519 small for gestational age infants (SGA), with a birth weight below the 10th percentile on our own growth curve, born in the region of University Central Hospital of Turku during the period June 1,1981‐May 31, 1982, was studied. The study population consists of 4 517 term, appropriate for gestational age (AGA) infants, 488 term SGA infants, 320 preterm AGA infants and 31 preterm SGA infants. The degree of intrauterine growth retardation (IUGR) seemed to have an effect on physical growth in term SGA infants. Those term SGA infants with a low Ponderal Index (PI) (type II) were taller and had a larger head circumference at the age of 24 months than term SGA infants with adequate PI (type I). Among the preterm SGA infants the degree of IUGR seemed to have no effect on later growth. Smoking is still one of the main risk factors associated with poor intrauterine growth. In this study we also found that smoking has an effect on later growth; the children of smoking mothers were smaller than those of non‐smoking mothers in the AGA group. Among the SGA infants the infants of non‐smoking mothers were bigger than those of smoking mothers. This difference could be explained by other factors associated with SGA. We found that in spite of the catch‐up growth during the first months, 26% of the severely SGA infants (birth weight below the 2.5th percentile) still had a weight below the 2.5th percentile at the age of 24 months.

Childhood bacterial meningitis: initial symptoms and signs related to age, and reasons for consulting a physician

The relationship of symptoms and signs to age and the reasons for consulting a physician were analyzed in 110 cases of culture-proven childhood bacterial meningitis. H. influenzae caused 74, meningococci 28, pneumococci 6 and streptococci 2 of the cases. Apart from fever (present in 94%), the most common symptoms according to age were as follows: 1–5 months: irritability (85%), 6–11 months: impaired consciousness (79%), 12 months or more: vomiting (82%) and neck rigidity (78%). Absence of neck rigidity at diagnosis was associated with young age (<12 months, P<0.001) and, in older children, to a short duration of symptoms (P<0.01) but not to the degree of CSF pleocytosis. Symptoms of meningitis caused by H. influenzae differed from those of meningococcal meningitis. Meningitis should be suspected in irritable or lethargic febrile children despite absence of neck rigidity. Fever and vomiting were the most frequent reasons for consulting a physician (60% and 31%, respectively). Despite the frequency and alarming character of irritability, impaired consciousness and neck rigidity, their presence led infrequently to a consultation (6%, 22% and 3%, respectively). Parental ignorance of such symptoms or of their importance may cause treatment delay, despite readily available medical services.

Elevated arterial blood pressure is associated with peri-intraventricular haemorrhage

In a prospective study, brain ultrasound scans were performed in 42 newborns (median birth weight 1700g, range 1020–3720 g; gestational age 32 weeks, 26–36) to reveal peri-intraventricular haemorrhage (PIVH) (grades I–IV) as well as echodensities (ED) and/or periventricular leucomalacia (PVL). ECG and arterial blood pressure were recorded on magnetic tape at 8h intervals during the first 24 h of life for further computer analysis. Heart rate (HR) and its variability (HRV) indices RMSM (long-term variability) and RMSSD (short-term variability), together with their coefficients of variation, were computed. Systolic (SBP), diastolic (DBP), and mean blood pressures (MBP) were detected as average values for 2-min stationary segments together with the respective minima and maxima. The indices of variability and their coefficients of variation were computed for the arterial pressure. PIVH was found in 12 newborns and ED in 8 (of whom two developed PVL). The remaining 22 served as controls. Neither HR, HRV nor BP variability differed between the groups. DBP was higher in the group with PIVH (39 mmHg) when compared to both the controls (33 mmHg,P<0.05) and the ED group (32 mmHg,P<0.01). MBP behaved respectively (45 mmHg, 38 mmHg, 37 mmHg,P<0.01). SBP behaved also similarly when gestational age and birth weight were used as covariates (57 mmHg, 48 mmHg, 47 mmHg,P<0.01).Our results suggest that elevated diastolic, mean and systolic blood pressure are significantly associated with peri-intraventricular haemorrhage in preterm newborn infants.

Cardiovascular monitoring in infants with respiratory distress syndrome.

Heart rate, short-term heart rate variability, long-term heart rate variability (LTV), mean arterial blood pressure and R-to-pulse time were recorded in 28 infants during the acute phase of respiratory distress syndrome (RDS). The patients were classified by a clinical scoring system into three classes related to the severity of the disease. The LTV was initially significantly (p less than 0.01) lower in infants with severe RDS (class III) than in those with moderate or mild disease (classes II and I). Only in class III the LTV increased significantly (p less than 0.001) during recovery. Also the mean arterial blood pressure was decreased in class III during the first 24 h of life. The R-to-pulse time proved not to be related to the severity of RDS. Reasonable assistance was achieved by multiparametric circulatory monitoring: a considerably disturbed circulatory control (tendency to hypotension and attenuated chronotropic cardiac control) was observed in the most severe form of RDS. No specific circulatory therapy was applied on the basis of the findings.

Water, Sodium and Acid‐Base Balance in Premature Infants: Therapeutical Aspects

ABSTRACT. One of the main targets of fluid therapy in premature infants is to avoid variations in osmolality, which mainly means providing a stable sodium, glucose, and acid‐base balance. Water, sodium, and acid‐base balance were measured in 20 infants appropriate‐for‐gestational age with a gestational age 34 weeks. The infants were randomly assigned to one of two treatment groups. Fluid intake was restricted and air humidity in the incubator was high in order to minimize insensible water loss. Sodium intake in Group 1 was 2 mmol/kg/day and consisted of sodium chloride. Sodium intake in Group 2 was 4 mmol/kg/day and consisted of both sodium chloride and acetate. Weight loss was appropriate in both groups. In the high sodium intake group there was a tendency towards a more stable plasma sodium concentration than in the low sodium intake group. The use of sodium acetate was efficient and practical as normal acid‐base balance was maintained. The protocol with restricted fluid intake (1st day 50 ml/kg, 2nd day 70 ml/kg, 3rd day 90 ml/kg, and 4th day 110 ml/kg), high air humidity, a sodium supply of 3 to 4 mmol/kg/day, and a slow correction of metabolic acidosis with sodium acetate, yields suitable guidelines in planning fluid and electrolyte therapy in premature infants 34 weeks gestation.

Sympathoadrenal activity in preterm infants during the first five days of life

We measured plasma concentrations of epinephrine (E), norepinephrine (NE), 3,4-dihydroxyphenylacetic acid (DOPAC), and 3,4-dihydroxyphenylglycol (DHPG) as well as urinary concentrations of metanephrine (M), normetanephrine (NM) and 3-methoxy-4-hydroxymandelic acid (MOMA) on day 2 and day 5 in preterm infants; gestational age less than 30 weeks (G less than 30; n = 16) and gestational age 30-34 weeks (G 30-34; n = 19). Concentrations of E (0.00-2.28 nmol/l) and NE (0.6-9.1 nmol/l) in plasma were much lower than those previously reported during preterm and term delivery. The E:NE ratio decreased from 1:10 on day 2 to 1:30 on day 5, and the M:NM ratio decreased from 1:4 on day 2 to 1:8 on day 5, indicating relatively higher catecholamine secretion from the adrenals than from the sympathetic nerve terminals in preterm infants during postnatal adaptation. Plasma concentrations of DOPAC and DHPG were significantly higher in G less than 30 than in G 30-34 (DOPAC, p = 0.0494; DHPG, p = 0.0092), probably relating to a low urinary excretion rate of catecholamine metabolites in infants in G less than 30. Plasma and urinary concentrations of catecholamines and their metabolites varied considerably, and no significant correlations to postnatal events could be demonstrated.

Cerebral metabolic rate for glucose after neonatal hypoglycaemia

OBJECTIVEnWe studied the effect of neonatal hypoglycaemia on the local cerebral metabolic rate for glucose (LCMRglc).nnnMATERIALS AND METHODSnEight newborn infants with neonatal hypoglycaemia were studied. The LCMRglc in the whole brain, in five cerebral regions and in skeletal muscles were quantitated using positron emission tomography (PET) and 2-[18F]Fluoro-2-deoxy-D-glucose (FDG). The PET studies were performed at the age of 5.3 +/- 6.2 days during normoglycaemia. The LCMRglc of these infants were compared to the age-adjusted LCMRglc of eight infants with suspected hypoxic-ischaemic brain injury but with normal neurological development.nnnRESULTSnAfter neonatal hypoglycaemia the age-adjusted LCMRglc in the whole brain was not lower than LCMRglc of the control infants (5.33 +/- 0.60 mumol/100 g/min vs. 6.71 +/- 0.60 mumol/100 g/min). Also the metabolic rate for glucose (MRglc) in the skeletal muscles was similar in hypoglycaemic and control infants (5.56 +/- 2.48 mumol/100 g/min vs. 6.99 +/- 2.41 mumol/100 g/min).nnnCONCLUSIONnMRglc in brain and in skeletal muscle seems to be normal after neonatal hypoglycaemia, although larger group of patients with more severe hypoglycaemia are needed to confirm this finding.

Renal Function in Preterm Infants during the First Five Days of Life: Influence of Maturation and Early Colloid Treatment

We measured the influence of maturation and early freshly frozen plasma infusion (FFP) on renal function (day 2 and day 5) in preterm infants in intensive care; they were divided into two groups, those with gestational ages less than 30 weeks (G less than 30) and those with gestational ages of 30-34 weeks (G 30-34). A total of 35 infants was studied. The infants were randomly assigned to one of two treatment groups, one receiving FFP, the other not, yielding four study groups; G less than 30 and no FFP (8 infants), G less than 30 and FFP (8 infants), G 30-34 and no FFP (9 infants) and G 30-34 and FFP (10 infants). The infants in the two FFP groups received FFP 10 ml/kg on days 1-3. FFP did not significantly influence creatinine clearance (CCr) or the urinary sodium excretion rate either in G less than 30 or G 30-34. CCr was significantly lower (p less than 0.001) and fractional urinary sodium excretion significantly higher (p less than 0.002) in infants of G less than 30 than in infants of G 30-34. Infants of G less than 30 had significantly higher plasma potassium concentrations (p less than 0.01) than infants of G 30-34. Despite the low CCr and the high urinary sodium excretion rate, infants of G less than 30 had stable fluid and electrolyte balance.

Extracellular volume in preterm infants: influence of gestational age and colloids.

We assessed the effect of fresh frozen plasma (FFP) on extracellular volume (ECV) during the first few days of life in two groups of preterm infants, group 1 (gestational age less than 30 weeks) and group 2 (gestational age 30-34 weeks). The infants were randomly assigned to one of two treatment groups, one receiving FFP, the other not; group 1 infants receiving no treatment (n = 8) and group 1 infants receiving FFP (n = 11), and group 2 infants receiving no treatment (n = 9) and group 2 receiving FFP (n = 10). FFP was given at a dose of 10 ml/kg daily during a two-hour period for the first three days of life. ECV was measured on day 1 before FFP was given and on day 4 by the distribution of bromide. There was a significant correlation between birth weight and initial ECV (r = 0.85, P less than 0.001). In group 1 ECV was significantly higher than in group 2 (P less than 0.02). In group 1 receiving no treatment mean weight loss and mean decrease in ECV were equal (84 g/kg and 78 ml/kg, respectively), but no correlation between the two parameters could be found (r = 0.68, P = 0.06). In the other study groups, mean weight loss was higher than mean decrease in ECV, with no correlation between weight loss and change in ECV.(ABSTRACT TRUNCATED AT 250 WORDS)

Cerebral circulation assessed by transcephalic electrical impedance during the first day of life — a potential predictor of outcome?

Pulsatile changes in intracranial blood volume (transcephalic electrical impedance, delta Z), arterial blood pressure (aBP) and respiration were studied during the first day after birth in 42 neonates with a birth weight of 1040-3850 g and gestational age of 26-36 weeks. The neurological outcome was assessed at 1 year of age to study the predictive ability of delta Z. delta Z, ECG, respirogram and direct aBP were recorded at 8-h intervals. Outcome was adverse in seven infants of whom two died from severe peri-intraventricular haemorrhage. PCO2 was higher (6.2 kPa) in the infants with adverse outcome than in those infants with favourable outcome (5.0 kPa) (P = 0.004). Blood glucose (4.5 vs. 3.3 mmol/l, P = 0.030) and first day administration of fluid (80 vs. 63 ml/kg/day, P = 0.003) behaved, respectively. Of the infants receiving dopamine therapy, 60% had adverse outcome while only 11% of those not receiving dopamine had adverse outcome (P = 0.016). Of the infants with high diastolic blood pressure levels, 32% had adverse outcome, while none with low diastolic blood pressure levels had adverse outcome (P = 0.031). Spectral analysis was used to examine signal variabilities in the frequency domain. During the first 24 h of life, the variabilities of aBP and respiration were equal in all the infants. The high-frequency delta Z signal variability (1.50-4.00 Hz, heart rate level) was found to be lower in the infants with adverse outcome (330 units) than in the infants with favourable outcome (1280 units, P = 0.017). The low delta Z variability allowed us to assume that there is a decrease of pulsatile cerebral blood flow (CBF) in the infants with adverse outcome. We speculate that this may result from the no reflow phenomenon, increased tissue pressure due to ischaemia and/or PIVH, the brain sparing effect or constriction of main cerebral arteries due to increased pressure support or metabolic factors (PCO2, glucose). We believe that transcephalic impedance provides a potential cot-side method for monitoring cerebral circulation in the neonatal period with an ability to predict outcome.