A national study of risk factors associated with mortality in very low birthweight infants in the Malaysian neonatal intensive care units

To determine the risk factors associated with mortality in very low birthweight (VLBW) infants admitted to the neonatal intensive care units (NIUC) in Malaysia.

Method:

A prospective observational study of outcome of all VLBW infants born between 1 January 1993 and 30 June 1993 and admitted to the NICU.

Results:

Data of 868 VLBW neonates from 18 centres in Malaysia were collected. Their mean birthweight was 1223 g (95% confidence intervals: 1208–1238 g). Thirty-seven point four per cent (325/868) of these infants died before discharge. After exclusion of all infants with congenital anomalies ( n =66, and nine of them also had incomplete records) and incomplete records ( n =82), stepwise logistic regression analysis of the remaining 720 infants showed that the risk factors that were significantly associated with increased mortality before discharge were: delivery in district hospitals, Chinese race, lower birthweight, lower gestation age, persistent pulmonary hypertension of the newborn, pulmonary airleak, necrotizing enterocolitis of stage 2 or 3, confirmed sepsis, hypotension, hypothermia, acute renal failure, intermittent positive pressure ventilation, and umbilical arterial catheterization. Factors that were significantly associated with lower risk of mortality were: use of antenatal steroid, oxygen therapy, surfactant therapy and blood transfusion.

Conclusion:

The mortality of VLBW infants admitted to the Malaysian NICU was high and was also associated with a number of preventable risk factors.     

Neonatal correlates of adverse outcomes in very low‐birthweight infants in the NICU Network

Background: The aim of the present study was to explore the relationships among neonatal morbidity, interventions and death or adverse neurodevelopmental outcomes in very low‐birthweight (VLBW) infants. Methods: Subjects were infants with birthweight ≤1500 g who were cared for in the tertiary neonatal intensive care units in Japan. Multiple logistic regression analysis was performed to examine the odds ratios (OR) and 95% confidence intervals (CI) of neonatal factors for death or cerebral palsy (CP) and death or developmental delay (developmental quotient <70 or delay judged by physicians) at 3 years of age after adjusting for biological and prenatal variables. Results: Of the 3104 subjects, 257 died and 1826 were evaluated at 3 years of age. Cystic periventricular leukomalacia (PVL; OR, 23.9; 95%CI: 11.0–51.7), gastrointestinal perforation (OR, 8.5; 95%CI: 2.8–25.4), intraventricular hemorrhage (IVH) grade 3 or 4 (OR, 3.1; 95%CI: 1.3–7.2) and sepsis (OR, 2.6; 95%CI: 1.4–4.8) were neonatal factors significantly associated with an increased risk of death or CP. Significant correlates with death or developmental delay were cystic PVL (OR, 7.9; 95%CI: 3.7–16.8), gastrointestinal perforation (OR, 6.3; 95%CI: 1.9–20.8), sepsis (OR, 2.8; 95%CI: 1.6–4.8), IVH grade 3 or 4 (OR, 2.6; 95%CI: 1.2–5.7), chronic lung disease at 36 weeks of corrected gestational age (OR, 1.6; 95%CI: 1.1–2.4) and treatment for retinopathy of prematurity (ROP; OR, 1.5; 95%CI: 1.0–2.3). Conclusion: Cystic PVL, gastrointestinal perforation, IVH and sepsis correlated with both death or CP and death or developmental delay in VLBW infants. Chronic lung disease at 36 weeks and treatment for ROP were associated with death or developmental delay, but not with death or CP.     

Perinatal factors affecting survival of very low birthweight infants — a study from two hospitals

ABSTRACT. Three hundred and seventy-seven consecutive liveborn infants with a birthweight between 500g and 1500g born at two perinatal centres in the calendar years 1977 and 1978 and 40 outborn infants in the same weight group admitted to one of the hospitals during the same period were studied. Although the survival rates in individual 100g weight groups vary between 14.3% and 97.4%, overall survival rates for inborn and outborn infants in both hospitals were similar, ranging from 69.0% to 71.5%. Twenty-two perinatal factors were found to have a significant effect on survival, of which 15 were common to the inborn populations in both hospitals. Eight of these 22 factors were indicators of intrapartum asphyxia. Multiple regression analysis showed that whereas birthweight was the most important variable influencing outcome in one hospital, the infant's condition at birth is the most important in the other. This difference may be related to the aggressive approach to perinatal intensive care of extremely preterm infants in the latter hospital.     

Outcomes of very‐low‐birthweight infants at 3 years of age born in 2003–2004 in Japan

Background: The aim of this study was to describe and compare neurodevelopmental outcomes with birthweight (BW) groups at 250‐g intervals of very‐low‐birthweight (VLBW) infants at 3 years of age in a multicenter cohort in Japan. Methods: A total of 3104 VLBW infants born in 2003 and 2004 registered in a NICU‐network database were followed in the study. Neurodevelopmental impairment (NDI) was defined as any of the following impairments: cerebral palsy, unilateral or bilateral blindness, severe hearing impairment, or developmental delay; a developmental quotient (DQ) <70 measured using the Kyoto Scale of Psychological Development test or judged by physicians in infants without the test. Results: A total of 257 infants died and follow‐up data were obtained from 1826 infants. Of the 1826 infants, 155 (8.5%) had cerebral palsy, 25 (1.4%) had visual impairment, and 12 (0.7%) had hearing impairment. Of the 1197 infants in whom DQ was measured, 184 (15.4%) had DQ < 70. The proportion of NDI in the evaluated infants was 19.2% (n= 350), ranging from 11.9% (BW 1251–1500 g) to 42.0% (BW ≤ 500 g). Odds ratios (95%CI) of NDI or death against the group BW 1251–1500 g were 20.62 (13.29–31.97) in BW ≤ 500 g, 7.25 (5.45–9.64) in BW 501–750 g, 2.85 (2.12–3.82) in BW 751–1000 g and 1.18 (0.85–1.64) in BW 1001–1250 g. Conclusion: The increasing proportion of NDI or death, an indicator of adverse outcome, was associated with decrement in the BW of the groups. Although we have to consider a bias due to loss of follow‐up data, the incidence of NDI was similar to previous overseas cohort studies despite the higher survival proportion in our study.     

Outcomes of herniotomy in premature infants: Recent 10 year experience

Background: The timing of herniotomy in premature infants is controversial. Methods: Outcomes of herniotomy in 47 premature infants admitted to the neonatal intensive care unit (NICU) were retrospectively reviewed for preoperative clinical features, respiratory interventions, and anesthetic and surgical complications. The data were compared with those of full‐term infants (n= 52). Fourteen of the premature infants underwent herniotomy before NICU discharge and 33 after discharge. The predictive factors for anesthetic and surgical complications were also investigated via multiple regression analysis. Results: Mean post‐conceptional age at surgery in premature infants and full‐term infants was 47 weeks and 50 weeks, respectively. Mean bodyweight at surgery in those infants was 4087 g and 5454 g, respectively. The rate of incarcerated hernia and emergency surgery was lower in premature infants. Delayed extubation of the tracheal tube after surgery was noted in four premature infants, but not in full‐term infants. Two cases of cryptorchidism in premature infants and one recurrence in a full‐term infant that required reoperation were noted. On multiple regression analysis no factor (including respiratory interventions) was found to be capable of predicting complications. Conclusion: Although no predictive factor for complications was identified, there were some anesthetic and surgical complications in premature infants. If there is no risk of incarceration, herniotomy in premature infants should be performed at a time when the risk of anesthetic complications is decreased. If there is a risk of incarcerated hernia, herniotomy should be performed carefully in order to avoid occurrence of anesthetic and surgical complications.     

Neonatal Outcome of Extremely Small Low Birth weight Liveborn Infants Below 901 g in a Swedish Population

ABSTRACT. In a regional population of 32120 liveborn newborn infants 65 (0.2%) had a birthweight ≤900 g (extremely small low birthweight = ESLBW) with mean gestational age 26.4 (range 22–31) completed weeks of gestation. The total 0–1 year survival rate was 48%. For the 42 infants treated in the Level III regional neonatal intensive care unit (NICU) the 0–1 year survival rate was 55% versus 34% for 23 infants not transferred to the Level III unit. In the ESLBW infants treated in the regional NICU the major complications were respiratory disorders requiring artificial ventilation (73%), bronchopulmonary dysplasia (26%), intracranial haemorrhages (40%), symptomatic persistent ductus arteriosus (36%) and sepsis (14%), persistent retinopathy of prematurity (8%). Duration of NICU treatment was 51 days (range 10–95) for survivors. Mode of delivery and rate of perinatal complications did not differ between survivors and non-survivors. Previous legal abortion occurred in 24%, fertility problems in 29% and 21% of the mothers, were immigrants. Otherwise no significant abnormalities were found in maternal or socioeconomic conditions. Factors deciding neonatal outcome in the tiniest babies seem to be a combination of prenatal circumstances and neonatal minute fine care procedures.     

Continuous gastric drip versus intravenous fluids in low birthweight infants

This multicentre randomized study compared a continuous gastric drip (CGD) with intravenous (i.v.) fluid administration. Healthy newborns with birthweight from 1501 to 2000 g whose physician ordered i.v. fluids were randomized before the 2nd hour of life to CGD or i.v. fluids. The major outcome variable was the need for an i.v. line in the CGD group. Serum glucose was measured at 30 min, 1 h and every 6 h thereafter. Serum sodium and potassium were measured at least once during the first 72 h of life. Enteral feedings, feeding intolerance, number of venous lines and i.v. line-related complications were recorded until the interruption of CGD or the i.v. line. Twenty-nine infants were randomized to each group. The two groups were comparable in terms of birthweight and gestational age. Ten percent (3/29) of the infants randomized to the CGD group required i.v. fluids and 90% of them received electrolytes and glucose through an orogastric tube. The incidence of hypoglycaemia, hyponatraemia and episodes of feeding intolerance did not differ between the groups. Conclusion: Fluid administration by CGD reduces the need for i.v. lines without increasing the risk of complications.     

Neonatal jaundice in 'healthy' very low birthweight infants

The daily bilirubin levels during the first week of life in 94 premature very low birthweight (VLBW, < 1500g) relatively 'healthy' infants were determined. Mean daily bilirubin values peaked on the fourth day of life at 188.1 μmol/l (s.e.m. = 5.3). Twenty-eight infants developed hyperbilirubinaemia (bilirubin > 260 μmol/l), at which time they were exposed to phototherapy. When individual peak bilirubin values were evaluated, the overall peak value was 213.9 μmol/l (s.e.m. = 5.1) occurring at 4.81 days (s.e.m. = 0.11), although the value is most likely an underestimate, since the 28 pre-phototherapy values were not truly peak values. Seventy-six (81%) infants experienced bilirubin levels > 170 μmol/l. The method of delivery apparently had no impact on the bilirubin levels.
All the infants remained well and progressed satisfactorily.'Healthy' VLBW infants experience a much greater incidence and severity of neonatal jaundice than mature infants with the same clinical status.     

A neonatal early discharge and home support programme: Shifting care into the community

Objective: The Neonatal Early Discharge and Family Support Programme (NEDP) was an initiative aimed at providing extended care for families whose infants had required neonatal special care, thereby allowing earlier discharge.
Methodology: Two groups of families were examined; one before and one after the instigation of the NEDP. Hospital and community service usage and psychosocial effects were examined.
Results: Families who received support were able to be discharged earlier and rooming-in was unnecessary as support was provided at home. Visits to family doctors for mothercraft issues were less frequent. Transport of babies from the Level 3 nursery to other nurseries in order to be closer to home was also provided by the nursing team, saving on ambulance costs and freeing their time for emergencies. There was no increase in maternal anxiety and infants were less difficult in the patient group.
Conclusions: NEDP and family support programme is a worthwhile extension of neonatal intensive care.     

Early neurodevelopmental outcome of very low birthweight infants

ABSTRACT. In the 18 months, January 1979 to July 1980, 149 infants who weighed ≤1500g at birth were cared for in the neonatal intensive care unit at Queen Victoria Medical Centre, Melbourne. During this period the neonatal survival rate for infants weighing 501–1000g was 57% and for those weighing 1001–1500g was 91%. Of the 123 neonatal survivors, four died within the first year after birth. One hundred and seventeen (98%) of 119 surviving infants have been assessed at follow-up. At a mean age of 12.3 months (corrected for prematurity), 11 (9%) survivors had physical handicaps only and four (3%) had developmental delay, including one child who was also physically handicapped. Nine of the 14 children with a defined handicap were considered to have significant functional handicap. Therefore 108 (92%) survivors are able to function within the normal range. These results suggest that the chance of survival for infants of very low birthweight has continued to increase whereas their handicap-rate has remained stable and relatively low.     

Linguistic skills at 6 1/2 years of age in children who required neonatal intensive care in 1986-1989

Linguistic skills at 6 1/2 y of age, corrected for gestational age at birth, were examined in a cohort of 230 children who had required neonatal intensive care (NIC) in 1986-89, and in 71 fullterm neonatally healthy control children (C) matched to the NIC children born at < 32 gestational weeks. Ten linguistic areas were assessed. The 10th percentile score of the controls was identified in each linguistic area and used for comparisons. In 77.5% of the controls and 63.5% of the NIC children, no score was lower than the 10th percentile score of the controls. Scores lower than the 10th percentile score were more common in NIC children born at term or at 23-31 wk, and within this group of children those born at 23-27 wk, than in controls. Conclusion: In preterm children of < 32 wk the results in the linguistic areas of imitation of articulatory positions, comprehension of logical grammatical constructions, phonemes and word fluency differed from those of the matched controls, and in NIC children born at > or = 32 weeks the results for imitation of articulatory positions, articulatory patterns and sentences, auditory discrimination and word fluency were poorer than those of the controls.     

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.     

Pulmonary hemorrhage in very low‐birthweight infants: Risk factors and management

Background: Beginning 2007, the intratracheal route of epinephrine to end massive pulmonary hemorrhage (MPH) in very low‐birthweight (VLBW) infants was modified at Kaohsiung Veterans General Hospital. The aim of the present study was to assess the change in outcomes for these infants, and to evaluate the risk factors of MPH. Methods: Using the database of the Premature Baby Foundation of Taiwan, the mortality, risk factors and characteristics of VLBW infants with or without MPH were compared between 2000–2006 and 2007–2010. Results: Between January 2000 and December 2010, 399 VLBW infants were admitted to Kaohsiung Veterans General Hospital. Mean birthweight (BW) was 1099.6 ± 272.7 g, and mean gestational age (GA) was 28.7 ± 2.9 weeks. The overall survival rate was 84.2%. Sixteen (4%) had MPH: 11 in the first group (2000–2006; 18.2% survival rate), and five in the second group (2007–2010; 80% survival rate; P= 0.0000002). Infants with MPH had lower mean BW (864.9 ± 301.4 g, P= 0.0004), smaller mean GA (26.1 ± 2.0 weeks, P= 0.0002), significantly lower Apgar scores at 1 and 5 min, higher severity of respiratory distress syndrome (RDS; grades 3 or 4), and greater use of surfactant than infants without MPH. They also had more intraventricular hemorrhage and higher mortality. Conclusions: Smaller GA, lower BW, lower Apgar scores at 1 and 5 min, severe RDS (grades 3 or 4), and use of surfactant place VLBW infants at greater risk of MPH. Proper prenatal care and preventing premature labor and delivery were the most important preventative factors. A quick, deep thrust of intratracheal epinephrine with a catheter may improve survival.     

Periventricular haemorrhage and leukomalacia in extremely low birthweight infants

Forty (49%) of 82 extremely low birthweight (ELBW, <1000 g) infants had periventricular haemorrhage (PVH). Ten (12%) had germinal layer haemorrhage (GLH) alone, 16 (20%) had intraventricular haemorrhage (IVH) and 14 (17%) had intracerebral haemorrhage (ICH). Almost all the cases of PVH had developed by 4 days of age. Small-for-gestational age infants (12% of study population) had a significantly lower incidence and severity of PVH than appropriate-for-gestational age infants. Of 94 infants born between 23 and 28 weeks gestation, 45 (48%) had PVH. The PVH incidence was 60% in those of 23-26 weeks and 38% in those of 27-28 weeks. The hospital survival rate of ELBW infants was 69% in those without PVH and 43% in those with PVH; 70% in GLH alone; 50% in IVH and 14% in ICH. Three survivors developed post-haemorrhage hydrocephalus of whom two required ventriculoperitoneal shunting. Five survivors developed periventricular leukomalacia (PVL) evidenced by cysts identified between 3 and 7 weeks of age. A significant decrease in the incidence of PVH occurred over the study period (67% in 1982, 38% in 1983 and 33% in 1984). This decrease was seen for ail grades of PVH. The reasons for this decreased incidence are still to be ascertained but this trend suggests that improvements in neonatal intensive care have the potential to improve the neurological outcome of more recent ELBW survivors.     

Surgery is safe in very low birthweight infants with necrotizing enterocolitis

The aim of this study was to determine how the operative event itself affects very low birthweight (VLBW) infants (< 1500 g) with necrotizing enterocolitis (NEC) undergoing surgery, and to try to identify preventable factors leading to perioperative morbidity and mortality. Eighty-five VLBW infants developed NEC during a 6-year period; 34 of those required emergent celiotomies. Data were collected retrospectively from hospital charts available on 33 infants. Birthweight ranged from 566 g to 1415 g (mean +/- SD: 961+/-262 g) and gestational age from 24 to 34 wk (28+/-3.2 wk). Thirty infants had been fed premature formula (first feed at 5+/-3.6 d) prior to the onset of symptoms and three had not been fed at all. Age at NEC symptoms was 19+/-15 d. Infants < 1000 g developed NEC much longer after the first feed compared to infants > 1000 g (p < 0.002; t-test). In 42% of the children, intraoperative blood pressure fell at least 20% from the preoperative value. Body temperature dropped from a preoperative 36.5+/-0.340 degrees C to 35.5+/-1.20 degrees C (p < 0.005), although in all children two or more heating devices were employed in the operating room. All infants survived the procedure. Six infants with pannecrosis died within 72 h of the operative event. In an appropriate setting, operative intervention under general anesthesia is well tolerated by VLBW infants with NEC. Since hypothermia was a major problem, the authors have modified their approach and now no longer transport these infants to the operating room. Instead, these infants are operated upon in the neonatal intensive care unit, directly on an infant radiant warmer system.