Clinical spectrum of neonatal apnoea in very low birthweight infants

This study quantifies apnoea and assesses the response to xanthine derivatives amongst 172 consecutively born, surviving very low birth weight (VLBW) infants, 136 appropriate weight for gestational age (AGA), 36 small for gestational age (SGA). All babies had electronic monitoring of heart and respiratory rates and nursing staff recorded episodes of apnoea (greater than 10 s), bradycardia (less than 100) and cyanosis. Only 42 (24.2%) babies had no episodes recorded. (25 AGA, 17 SGA). Sixty-four (37.2%) received active resuscitation on at least one occasion with six babies ventilated by bag and mask on more than 10 occasions. Apnoea had commenced by day 10 of life in all the babies who had apnoea and persisted beyond day 50 in only six; however four of these infants were still requiring active resuscitation. Apnoea had ceased by 37 weeks post-conceptual age in 88% and by 40 weeks in all but three babies. Risk factor analysis revealed a strong correlation (P less than 0.005) with lower gestational ages and birth weights, respiratory distress syndrome (RDS) and the problems associated with it, such as mechanical ventilation, patency of the ductus arteriosus (PDA) and chronic neonatal lung disease. A single, reversible cause for apnoea was rarely demonstrated. Care must be exercised with feeding, physiotherapy and suctioning the pharynx and trachea of 'at risk' infants. Xanthine derivatives were highly effective in decreasing the frequency of recurrent apnoea from a mean of 10.08 episodes one day before, to 1.83 two days after commencement of treatment.     

Clinical spectrum of neonatal apnoea in very low birthweight infants

Abstract This study quantifies apnoea and assesses the response to xanthine derivatives amongst 172 consecutively born, surviving very low birth weight (VLBW) infants, 136 appropriate weight for gestational age (AGA), 36 small for gestatfonal age (SGA). All babies had electronic monitoring of heart and respiratory rates and nursing staff recorded episodes of apnoea (> 10 s), bradycardia (<100) and cyanosis. Only 42 (24.2%) babies had no episodes recorded. (25 AGA, 17 SGA). Sixty-four (37.2%) received active resuscitation on at least one occasion with six babies ventilated by bag and mask on more than 10 occasions. Apnoea had commenced by day 10 of life in all the babies who had apnoea and persisted beyond day 50 in only six; however four of these infants were still requiring active resuscitation. Apnoea had ceased by 37 weeks post-conceptual age in 88% and by 40 weeks in all but three babies.
Risk factor analysis revealed a strong correlation (P<0.005) with lower gestational ages and birth weights, respiratory distress syndrome (RDS) and the problems associated with it, such as mechanical ventilation, patency of the ductus arteriosus (PDA) and chronic neonatal lung disease. A single, reversible cause for apnoea was rarely demonstrated. Care must be exercised with feeding, physiotherapy and suctioning the pharynx and trachea of 'at risk' infants. Xanthine derivatives were highly effective in decreasing the frequency of recurrent apnoea from a mean of 10.08 episodes one day before, to 1.83 two days after commencement of treatment.     

Hyperkalemia in very low birthweight infants: incidence and associated factors

The present study evaluated the incidence of hyperkalemia in premature babies born at the Hospital de Clínicas de Porto Alegre (birthweight or=6 mEq/l) and 15.4% with potassium levels subject to cardiac arrhythmia (>or= 6.7 mEq/l). The population was divided into two groups: group KN with potassium < 6 mEq/l (n=16) and group KE with potassium >or= 6 mEq/l (n=10). The hydroelectrolyte management and maintenance of neutral thermal environment was the same for both groups. Neither group received potassium in the first 36 hours of life. The KE group presented higher potassium levels during all the study. The mean birthweights of the groups were similar (KN = 963 gr; KE = 987 gr). The KN group presented a mean gestational age (29.3 weeks x 30.8 weeks) and Apgar Score in the first minute of life (3.18 x 5.7) significantly lower (p = 0.004 and p = 0,015 respectively) than the KE group. There were no significant differences between both groups in relation to the intraventricular hemorrhage, acidosis, hialine membrane disease, insulin level, glycemia, glycemia/insulin index, glomerular filtration rate, diurese, urinary potassium level, fractional sodium excretion, fractional potassium excretion and aldosterone tubular index. The level of aldosterone was significantly higher in the KE group (p = 0.029) within 24 hours of life (212.8 ng/dl x 110.2 ng/dl). It is suggested that none of the studied factors is responsible for the non-oliguric hyperkalemia of the very low birthweight newborn infant, stressing, however, that the serum potassium level must be carefully controlled in those infants.     

Racial differences in respiratory-related neonatal mortality among very low birth weight infants

OBJECTIVE: To examine racial differences in the secular trends in respiratory-related neonatal mortality among very low birth weight (VLBW) infants in the United States, temporally associated with surfactant availability. DESIGN: Comparison of time trends in African American and non-Hispanic white (NHW) VLBW infants of cause-specific neonatal mortality and neonatal and infant mortality for 2 consecutive 3-year periods. RESULTS: From 1985 to 1988 there was no racial difference in the rate of decline of each mortality outcome. From 1988 to 1991 rates of decline in neonatal mortality caused by respiratory distress syndrome and by all respiratory causes were significantly greater for NHWs compared with African Americans. However, the rate of decline in nonrespiratory neonatal mortality was similar for African Americans and NHWs. Compared with African American VLBW infants, NHWs had a greater rate of decline in both neonatal (31% vs 20%; P <.01) and infant mortality (32% vs 21%; P <.01) during this period. CONCLUSIONS: Between 1988 and 1991, declines in neonatal mortality risks caused by respiratory distress syndrome and all respiratory causes were greater for NHW infants than for African American VLBW infants. The decline in nonrespiratory mortality risk showed no racial differences. These findings suggest possible racial disparities in timely access or racial differences in the efficacy of respiratory treatments for VLBW infants.     

Hearing loss in very low birthweight infants treated with neonatal intensive care.

The hearing of 111 perinatal intensive care survivors of birthweights 1500 g or less was assessed at a mean age of 6 1/2 years (range 4--12). These 111 infants included 86% of the long-term survivors of this birthweight cared for in the newborn unit of University College Hospital, London, during the years 1966--72. All these infants were nursed in commercially available incubators for periods ranging from 2 to 80 days (mean 37) in which the mean noise threshold was 65 dB. Ten (9%) had sensory neural nearing losses, one (1%) infant had a congenital conductive hearing loss, and 21 (19%) infants had exudative otitis media with a mean loss of 25 dB. Apnoeic attacks in the neotal period were the most significant predictors of hearing loss in these infants (P less than 0.05) and an indirect serum filirubin level of at least 170 micromol/l (10 mg/100 ml) in the neonatal period had an additive effect (P less than 0.05). There was no evidence that ambient noise had affected the hearing of these very low birthweight infants.     

Cerebral palsy in very low birthweight infants.

Eighty one very low birthweight survivors with cerebral palsy were matched with controls by sex, gestational age, and place of birth. Using discriminant analysis, the perinatal profiles for infants with cerebral palsy and their controls were shown to differ significantly. When infants with various types of cerebral palsy were analysed with their controls the discriminating variables differed. Diplegic infants could be differentiated from controls on antenatal variables alone, but significant discrimination of hemiplegic and quadriplegic infants required the addition of postnatal variables. Cranial ultrasound appearances differed appreciably between types of cerebral palsy. Future studies should differentiate between types of cerebral palsy and include ultrasound data. Cerebral palsy in very low birthweight infants is unlikely to prove a useful outcome indicator for neonatal intensive care.     

Medical expenses of neonatal intensive care for very low birthweight infants

ABSTRACT. The in-hospital medical expenses for 90 very low birthweight (VLBW) infants weighing 1500 g or less at birth, whose parents had private health insurance, was reported. The median total and daily charges per survivor was $5,883 and $70 respectively. The median total and daily charges per non-survivor was $1,113 and $450 respectively. The medical expenses per VLBW survivor calculated for all 375 VLBW infants, admitted for neonatal intensive care over the 4 year period, was $6,813. This ranged from $10,000 per survivor for the 11 survivors in the 501 g-750 g birthweight group to $5,363 per survivor for the 145 survivors in the 1251 g-1500 g birthweight group. As these charges were probably a small proportion of the resource costs in providing a neonatal intensive care service, society at large was bearing most of the cost. Nevertheless, we believe that with the present decline in neonatal mortality and morbidity in VLBW infants, the outcome of neonatal intensive care justifies the cost.     

Central venous catheterisation in very low birthweight infants.

Forty two premature babies (mean birth weight 980 g, mean gestation 27.6 weeks) had central venous lines inserted at a mean age of 10 days through the internal jugular vein because of poor peripheral venous access and for purposes of parenteral feeding and minimal handling. Eight babies died from complications of prematurity and four from septicaemia with a central line in situ, but the other 30 babies had lines in place for a mean of 20 days. A mean weight gain of 17.5 g/kg/day was recorded. Eight babies showed signs of infection at a mean of 22 days after insertion of the line. The other complications were thrombosis related to the catheter (three cases), embolisation (two), and hydrocephalus related to superior vena caval thrombosis (one). The policy of management is outlined, and the risks and benefits of the technique are analysed.     

Phototherapy for hyperbilirubinaemia in very low birthweight infants.

Phototherapy was used to treat 20 newborn babies whose birthweight was below 1500 g and whose plasma bilirubin exceeded 8 mg/100 ml. The plasma bilirubin level was maintained below 13 mg/100 ml except in 4 babies whose level exceeded 13 mg/100 ml before treatment was started. In 60% of an untreated group of larger babies previously reported the plasma bilirubin level exceeded this figure. Phototherapy seems to control the plasma bilirubin level satisfactorily in very low birthweight infants, but frequent measurements on the second and third days of life are advised in order that treatment may be started promptly when it exceeds 8 mg/100 ml.     

Air embolism in ventilated very low birthweight infants.

Five cases of air embolism in ventilated very low birthweight infants are reported. In all cases the outcome was fatal with the babies dying at about 15 hours of age.     

Pulmonary interstitial emphysema in very low birthweight infants.

Forty six of 142 infants weighing less than 1500 g at birth, who had chest radiographs in the first 5 days of life, developed pulmonary interstitial emphysema (PIE) and in 19 this occurred in the first 24 hours. PIE was seen more frequently in infants weighing less than 1000 g at birth (24 of 57) than in those weighing 1000-1500 g (22 of 85). Ventilation for hyaline membrane disease was strongly associated with PIE, and only babies who were resuscitated, or ventilated, or had hyaline membrane disease developed the disorder. Most pneumothoraces were preceded by x-ray appearances of PIE (17 of 21). Mortality was increased in ventilated infants who developed PIE and was high in those with severe x-ray changes.     

Bronchopulmonary dysplasia in very low birthweight infants

ABSTRACT. Twenty-four (6%) of 375 infants with birthweights ≦1500g developed bronchopulmonary dysplasia (BPD); 16 (15%) of 107 in those ≦100g and 8 (3%) of 268 in those >1000g. The incidence was 10% in those who required assisted ventilation. Perinatal asphyxia, significant respiratory distress, pulmonary interstitial emphysema and patent ductus arteriosus were statistically more common in BPD infants compared with the remaining 351 very low birthweight infants. Hyaline membrane disease was the primary respiratory disease in 54% of BPD infants. The mean durations of oxygen and ventilatory therapy were 68 days and 37 days respectively. Twenty-nine percent did not require more than 60% oxygen for over 24 hours. Only 38% required a peak airway pressure of over 30 cmH₂O. Early postnatal growth was satisfactory on parenteral nutrition support. No perinatal factor was found to be predictive of death from BPD. The prolonged duration of hospital treatment has obvious implications to the psychosocial and economic costs of BPD.     

Late-onset neutropenia in very low birthweight infants

Aim : To evaluate the incidence and duration of late-onset neutropenia (defined as an absolute neutrophil count (ANC) <1500 mm⁻³ at a postnatal age of >3 wk) in a population of infants with birthweight <2000 g, and to determine whether copper deficiency, a possible cause of both anemia and neutropenia, may be associated with this complication. Methods : Complete blood cell count and differential were assessed in 247 low (LBW) and very low birthweight (VLBW) infants who were discharged after 3 wk of life. In neutropenic infants plasma copper and ceruloplasmin levels were also measured. Results : Late-onset neutropenia was detected in 11 out of 147 VLBW infants (7.5%) and in 7 out of 127 LBW infants (5.5%). A neutrophil count of <1000 mm⁻³ was observed in 14 infants (5.1%). A significantly lower gestational age was found in neutropenic infants compared with non-neutropenic infants. In neutropenic infants ANCs were significantly correlated with hemoglobin and hematocrit. In addition, a significant negative correlation was found between neutrophil and reticulocyte counts. Plasma copper concentration was significantly correlated with birthweight. Oral copper sulfate was administered to infants with plasma copper concentration <50 μg dl⁻¹, and did not seem to affect ANC, hemoglobin, hematocrit or reticulocyte counts.
Conclusion : Late-onset neutropenia appears to be a benign condition that is not associated with any particular complication and does not require specific treatment. Reference ranges after the early neonatal period and during the first few months of life in LBW and VLBW infants should probably be set at lower values.     

Bronchopulmonary dysplasia in very low birthweight infants

The incidence, clinical presentation and severity of bronchopulmonary dysplasia (BPD) in 110 consecutive very low birthweight (VLBW) infants admitted to the National University Hospital Neonatal Intensive Care Unit between October 1985 and January 1989 is reviewed. Thirty-two infants died, giving an overall survival rate of 70.9%. Sixty infants (54.4%) required mechanical ventilation in the first week of life; 24 (40%) of these infants died. Of the 36 survivors, 23 required oxygenation at 28 days of life and 21 fulfilled the criteria for BPD (35% of the 60 ventilated and 58% of the survivors). The incidence of BPD in all VLBW infants is 19% and of VLBW survivors 27%. Birthweight and gestational age appear to be important determinants. All the survivors in the 501-750 g birthweight group developed BPD compared to 6.25% in those above 1250 g. None of those greater than 30 weeks gestation developed BPD. Two forms of BPD were observed; the 'severe' group presented radiologically with chest radiographs characteristic of Stage IV BPD, while the 'mild' group with small or normal sized lungs demonstrated irregular strands of radio-densities alternating with areas of normal or increased lucency. The duration of mechanical ventilation and oxygen dependency were significantly longer in the 'severe' group, with the mean maximum peak inspiratory pressure, mean airway pressure, and FiO2 required in the first week of life being also significantly higher. Hyaline membrane disease was the main cause of respiratory failure requiring ventilation. The other causes were persistent pulmonary hypertension (1) and apnoea of prematurity (3); all of the latter developed only mild BPD.(ABSTRACT TRUNCATED AT 250 WORDS)     

Bronchopulmonary dysplasia in very low birthweight infants

Twenty-four (6%) of 375 infants with birthweights less than or equal to 1500g developed bronchopulmonary dysplasia (BPD); 16 (15%) of 107 in those less than or equal to 100g and 8 (3%) of 268 in those greater than 1000g. The incidence was 10% in those who required assisted ventilation. Perinatal asphyxia, significant respiratory distress, pulmonary interstitial emphysema and patent ductus arteriosus were statistically more common in BPD infants compared with the remaining 351 very low birthweight infants. Hyaline membrane disease was the primary respiratory disease in 54% of BPD infants. The mean durations of oxygen and ventilatory therapy were 68 days and 37 days respectively. Twenty-nine percent did not require more than 60% oxygen for over 24 hours. Only 38% required a peak airway pressure of over 30 cmH2O. Early postnatal growth was satisfactory on parenteral nutrition support. No perinatal factor was found to be predictive of death from BPD. The prolonged duration of hospital treatment has obvious implications to the psychosocial and economic costs of BPD.     

Late-onset neutropenia in very low birthweight infants

AIM: To evaluate the incidence and duration of late-onset neutropenia (defined as an absolute neutrophil count (ANC) <1500 mm(-3) at a postnatal age of >3 wk) in a population of infants with birthweight <2000 g, and to determine whether copper deficiency, a possible cause of both anemia and neutropenia, may be associated with this complication. METHODS: Complete blood cell count and differential were assessed in 247 low (LBW) and very low birthweight (VLBW) infants who were discharged after 3 wk of life. In neutropenic infants plasma copper and ceruloplasmin levels were also measured. RESULTS: Late-onset neutropenia was detected in 11 out of 147 VLBW infants (7.5%) and in 7 out of 127 LBW infants (5.5%). A neutrophil count of <1000 mm(-3) was observed in 14 infants (5.1%). A significantly lower gestational age was found in neutropenic infants compared with non-neutropenic infants. In neutropenic infants ANCs were significantly correlated with hemoglobin and hematocrit. In addition, a significant negative correlation was found between neutrophil and reticulocyte counts. Plasma copper concentration was significantly correlated with birthweight. Oral copper sulfate was administered to infants with plasma copper concentration <50 microg dl(-1), and did not seem to affect ANC, hemoglobin, hematocrit or reticulocyte counts. CONCLUSION: Late-onset neutropenia appears to be a benign condition that is not associated with any particular complication and does not require specific treatment. Reference ranges after the early neonatal period and during the first few months of life in LBW and VLBW infants should probably be set at lower values.