Postnatal dexamethasone treatment and retinopathy of prematurity in very-low-birth-weight neonates

Whether postnatal dexamethasone treatment for bronchopulmonary dysplasia (BPD) increases the risk of retinopathy of prematurity (ROP) in very-low-birth-weight (VLBW) neonates is uncertain. We performed a retrospective cohort study to determine the association between dexamethasone administered postnatally and the development of ROP in VLBW (< or = 1,250 g birth weight, < or = 32 weeks' gestational age at birth) neonates. The incidence of severe ROP (stage 2 or higher) was 26% among 72 infants who received no dexamethasone postnatally, 61% among 23 infants who received a low cumulative dexamethasone dose (< or = 1.8 mg/kg body weight), and 85% among 20 infants who received a high cumulative dexamethasone dose (> 1.8 mg/kg body weight). However, after adjustment for confounding covariates of prematurity and severity of lung disease by logistic regression analysis, we found no independent association between postnatal dexamethasone treatment and the incidence of severe ROP.     

Multicenter study to assess safety and efficacy of INH-A21, a donor-selected human staphylococcal immunoglobulin, for prevention of nosocomial infections in very low birth weight infants

BACKGROUND: Prophylactic administration of intravenous immunoglobulin has been inconsistent in reducing the risk of sepsis in very low birth weight (VLBW) infants presumably because of varying titers of organism specific IgG antibodies. INH-A21 is an intravenous immunoglobulin from donors with high titers of antistaphylococcal antibodies. This dose-ranging study explored safety and preliminary activity of INH-A21 for prevention of staphylococcal sepsis in VLBW infants. METHODS: This was a multicenter, double blind, group-sequential study. Infants with birth weights 500-1250 g were randomized to receive up to 4 doses of placebo, 250 mg/kg, 500 mg/kg or 750 mg/kg INH-A21. Safety and frequencies of sepsis were compared across treatment groups. RESULTS: All treatment groups had similar mean gestational age, birth weight, Apgar score and maternal use of antibiotics. Randomizations to 250 mg/kg (N = 94) and 500 mg/kg (N = 96) doses were terminated after interim analyses demonstrated a low probability of finding a difference when compared with placebo. Infants randomized to the INH-A21 750 mg/kg group (N = 157) had fewer episodes of Staphylococcus aureus sepsis [relative risk (RR), 0.37; 95% confidence interval (CI), 0.12-1.12; P = 0.14], candidemia (RR 0.34; 95% CI 0.09-1.22; P = 0.09) and mortality (RR 0.64; 95% CI 0.25-1.61; P = 0.27) when compared with the placebo-treated cohort (N = 158). No dose-related trends were observed for adverse events or morbidities associated with prematurity. CONCLUSIONS: INH-A21 750 mg/kg demonstrated potential to reduce sepsis caused by S. aureus, candidemia and mortality in VLBW infants. Although statistical significance was not reached, based on the magnitude of the estimated differences, the efficacy and safety of INH-A21 750 mg/kg should be evaluated in an adequately powered, well-controlled study.     

Teratogenicity of Azosemide, a Loop Diuretic, in Rats, Mice and Rabbits

Teratogenic effects of azosemide, a loop diuretic, were investigated in rats, mice and rabbits. Azosemide was given orally to pregnant rats, mice and rabbits during organogenesis. The pregnant animals were killed at term and their fetuses were examined for external, visceral and skeletal abnormalities. In rats, azosemide at 10–30 mg/kg/day did not affect intrauterine growth, resorptions and rates of external and visceral malformations. Treatment with 90 mg/kg/day resulted in a significant increase in skeletal abnormalities such as wavy ribs, bent scapula and bent humerus. However, the skeletal abnormalities observed in term fetuses could not be found in adult offspring, indicating that they were temporary. In mice, 1250 mg/kg/day of azosemide caused maternal death, abortion, and retarded maternal and fetal weight. Treatment with 200–500 mg/kg/day did not induce fetal mortalities, external and visceral malformations. Skeletal abnormalities increased in dose-dependent fashion. The type of abnormalities was identical to that encountered in rat fetuses. Furosemide as a positive control also produced similar types of skeletal abnormalities in mouse fetuses. In rabbits, azosemide did not have embryolethal or teratogenic effects even at the highest dose (6 mg/kg/ day), which caused maternal death. Treatment for a different 3-day period and then a different day during organogenesis in rats and mice showed that the sensitive period was days 15–17 of gestation with a peak on day 16 in rats, and days 12–15 with a peak on day 13 in mice.     

不同剂量氨茶碱在极低出生体重儿中的药代动力学及药效学研究

目的 探索不同剂量氨茶碱在不同校正胎龄、体重及日龄的极低出生体重儿中药代动力学和药效学特点。方法 选取发生呼吸暂停的极低出生体重儿40例,予以负荷剂量(5 mg/kg)氨茶碱静脉注射后随机分为两组,分别给予不同维持剂量(1 mg/kg及2 mg/kg,每8 h给药一次)。在治疗后8 h、3 d、7 d监测血药浓度及肝肾功能,记录呼吸暂停发作情况,比较两组药代动力学数据。结果 2 mg/kg组的稳态血药浓度、血浆清除率明显高于1 mg/kg组,半衰期低于1 mg/kg组(P<0.05)。2 mg/kg组患儿生后7 d内呼吸暂停发作天数明显较1 mg/kg组少(P<0.05)。两组患儿的氨茶碱血浆清除率与生后日龄及校正胎龄呈正相关(P<0.05)。结论 极低出生体重儿中不同维持剂量氨茶碱药代动力学及药效学参数具有差异,2 mg/kg氨茶碱治疗呼吸暂停效果优于1 mg/kg;临床上对氨茶碱进行剂量调整时应考虑患儿校正胎龄及生后日龄,同时进行常规血药浓度监测。     

Indomethacin prophylaxis for intraventricular hemorrhage in very low birth weight babies

OBJECTIVE: To study the efficacy and complications of low dose indomethacin in the reduction of major intraventricular hemorrhage (IVH) in very low birth weight (VLBW) babies. DESIGN: prospective randomized controlled trial (interim analysis) SETTING: Level III neonatal intensive care unit of a perinatal tertiary care center. PATIENTS: Newborn babies with birth weights between 750-1250 g were randomized into indomethacin or control groups. They were further stratified into two birth weight groups 750-999 g and 1000-1250 g for subgroup analysis. INTERVENTIONS: 3 doses of indomethacin were administered to the indomethacin group at the dose of 0.1 mg/kg/dose intravenously. The control group did not receive any specific intervention other than standard neonatal intensive care. OUTCOME MEASURES: The primary outcome measure was the occurrence of IVH and the secondary outcome measures were necrotising enterocolitis, symptomatic patent ductus arteriosus (PDA), bleeding episodes, renal failure, chronic-lung disease and death. RESULTS: Out of 115 eligible newborn babies, 56 babies received indomethacin and 59 were controls. Perinatal characteristics were similar between the two groups. There was no difference in the incidence of IVH between the groups but on subgroup analysis the incidence of major IVH (grades III and IV) were significantly increased in babies in the lower birth weight category who received indomethacin P = 0.03). The incidence of chronic lung disease was significantly higher in the indomethacin group (P = 0.005) and bleeding episodes other than IVH were also significantly increased in the indomethacin group (P = 0.04) in the lower birth weight category. The incidence of PDA was lower in the indomethacin group but only reached significant level in the higher birth weight subgroup (P = 0.02). There were no significant differences in the other outcome measures studied. CONCLUSIONS: Indomethacin prophylaxis did not confer protection against IVH in very low birth weight babies. Instead it showed an increase in the risk of IVH, other bleeding episodes and chronic lung disease. Based on this data we felt that we were not ethically justified in continuing the use of indomethacin and have since terminated this study.     

Slow versus fast enteral feed advancement in very low birth weight infants: a randomized control trial

OBJECTIVE: To evaluate the tolerance of rapid advancement of enteral feeds in VLBW babies. SETTING: Tertiary teaching hospital. DESIGN: Randomized controlled trial. METHODS: All stable neonates with birth weight less than 1250 grams were included in the study. The primary outcome variable was the time taken to achieve full enteral feeds (defined as 180 ml/kg/day). The secondary outcome variables were incidence of Necrotizing enterocolitis (NNEC) and incidence of apnea. At 48 hours, the infants were randomized into the slow advancement group (enteral feeds advanced by increments of 15 ml/kg/day) or fast advancement group (enteral feeds advanced by increments of 30 ml/kg/day). The monitoring during feeding included daily weight record, two hourly abdominal girth charting, gastric aspirates, apnea, time taken to reach full enteral feedings and for NNEC. RESULTS: There were 53 infants who were enrolled for the study (27 in the fast advancement group and 26 in the slow advancement group). In the fast advancement group, 20 percent completed the trial; whereas 14 (53.8 percent;) in the slow advancement group completed the study. The two groups were comparable for birth weights, gestational age, sex, intrauterine growth status, Apgar and CRIB scores. The infants in the fast group reached full enteral intake of 180 ml/kg/day significantly earlier (10 +/- 1.8 days) than in the slow group (14.8 +/- 1.5 days). The two groups were comparable for episodes of feed intolerance, apnea, NNEC. Infants in the fast group regained birth weight significantly earlier (median 18 days) than in the slow advancement group (median 23 days). CONCLUSIONS: Stable VLBW neonates can tolerate rapid advancements of enteral feeding without increased risk of adverse effects.     

Incidence of necrotizing enterocolitis in very‐low‐birth‐weight infants related to the use of Lactobacillus GG

Background: One of the five level III neonatal intensive care units (NICU) in Finland has used prophylactic Lactobacillus GG (LGG) for very‐low‐birth‐weight (VLBW) infants since 1997. Aim: To examine retrospectively the incidence of necrotizing enterocolitis (NEC) in all five university hospital NICUs in Finland in relation to the use of LGG during the years each unit has belonged to the Vermont Oxford Network (VON). Methods: The incidence of NEC was analysed from the national database and from the VON databases separately in all five level III NICUs and additionally in three groups according to the probiotic practice in the hospitals: prophylactic LGG group, probiotics ‘on demand’ group and no probiotics group. Results: The incidence of NEC was 4.6% vs. 3.3% vs. 1.8% in the prophylactic LGG group, the probiotics ‘on demand’ group and the no probiotics group, respectively; p = 0.0090, chi‐square. LGG had no influence on the clinical course of NEC. Conclusions: The results of this retrospective report failed to show that LGG prophylaxis protects VLBW infants from the occurrence of NEC, in contrast to previously published results. Our results call for more research regarding effective ways to administer probiotics, including data on appropriate bacteria, strain, dose and timing of administration to achieve clinically robust effects.     

Probiotics for the prevention of necrotising enterocolitis in very low‐birth‐weight infants: a meta‐analysis and systematic review

We performed an updated meta‐analysis incorporating the results of recent randomised controlled trials (RCTs) to measure the effectiveness of probiotic supplementation in preventing necrotising enterocolitis (NEC) and death in very low‐birth‐weight (VLBW) infants, and to investigate any differences in efficacy by probiotic agent. Using meta‐regression analysis, we assessed the contribution of other measured variables on the overall effect size and between‐study variability. Conclusion: Overall, probiotics lead to significant reductions in NEC incidence and mortality in VLBW infants. Differences in probiotic agents and the influence of prenatal steroids and feeding regimens may explain the differences in outcomes between studies.     

Effect of Bifidobacterium administration on very‐low‐birthweight infants

Background: The aim of this study was to evaluate the efficacy and safety of early administration of Bifidobacterium bifidum OLB6378 (B. bifidum) on accelerating enteral feeding and bacterial colonization in very‐low‐birthweight (VLBW) infants. Methods: We conducted a single‐center prospective pilot study. Thirty‐six VLBW infants were randomly divided into two groups: group E, wherein B. bifidum was supplemented within 48 h of birth, and group L, wherein it was supplemented more than 48 h after birth. Results: Group E and group L reached a total feeding volume of 100 mL/(kg/day) after 10 [7–13] days and 11 [10–15] days, respectively (median [quartile]). The daily bodyweight gain in group E was significantly higher (21.4 ± 3.2 g/day vs 18.3 ± 4.0 g/day, P < 0.02; 11.1 ± 1.5 g/kg/day vs 10.4 ± 1.2 g/kg/day, P < 0.04). No significant differences were found in the fecal Bifidobacterium level between the groups quantitated with a real‐time polymerase chain reaction assay at 1 and 4 weeks of age. However, the highest colonization rate of Bifidobacterium was observed when the supplementation started between 24 and 48 h after birth. The incidence of morbidities between the groups was similar. Conclusion: The early administration of B. bifidum to VLBW infants seems effective in promoting growth during the stay in the neonatal intensive care unit without increasing the incidence of morbidity. Furthermore, the preferable timing of starting the probiotic supplementation for VLBW infants is at latest less than 48 h after birth.     

Long-term enteral glutamine supplementation in very low birth weight infants: effects on growth parameters

Enteral and parenteral glutamine supplementation in preterm infants has been shown to have some beneficial effects on neonatal morbidity and mortality, although the results are controversial. In this study, we aimed to determine if long-term glutamine-supplemented enteral nutrition affects growth parameters in very-low-birth-weight (VLBW) preterm infants. Preterm infants with a birth weight of < or = 1500 g were assigned to receive enteral glutamine supplementation (300 mg/kg/day) or placebo between 8-120 days (4 months) of life. At the end of each month, growth parameters [weight, length, head circumference, left upper mid-arm circumference (MAC) and left mid-thigh circumference (MTC)] were determined and enteral glutamine dose was adjusted according to the current weight. In VLBW infants (n = 69), the glutamine-supplemented group (n = 36) had significantly higher mean weight, length, head circumference, MAC and MTC than the control group (n=33) at the end of the fourth month. These findings suggest that long-term enteral glutamine supplementation may lead to significant improvements in growth in all body measures in VLBW infants, possibly in a time-dependent pattern.     

Efficacy and tolerability of EPs 7630 in patients (aged 6–18 years old) with acute bronchitis

Aim: For EPs‐7630, a herbal drug preparation from Pelargonium sidoides roots, therapeutic effects in respiratory tract infections outside the strict indication for antibiotics have already been demonstrated in adults. Now, a dose‐finding study for EPs‐7630 was performed in children and adolescents. Methods: A total of 400 patients (aged 6–18 years) were randomized to receive either 30 mg, 60 mg or 90 mg EPs‐7630 or placebo daily. Primary outcome criterion was the change in the Bronchitis Severity Score (BSS) from day 0 to day 7. Results: After 7 days of treatment, the change in the BSS total score was significantly better in the 60 mg and 90 mg groups compared with placebo that of the without relevant differences between these two dosages. Especially ‘coughing’, ‘sputum’ and ‘rales at auscultation’ improved under EPs‐7630. Onset of effect was faster, time of bed rest shorter and treatment outcome and satisfaction with treatment were rated better. Tolerability was comparable with placebo in all treatment groups. Conclusion: EPs‐7630 is effective in acute bronchitis outside the strict indication for antibiotics in 6–18 years old patients, with a dose of 60 mg or 90 mg daily offering the best benefit/risk ratio. EPs‐7630 significantly reduces the severity of symptoms, leads to a more favourable course of the disease and a faster recovery from acute bronchitis compared with the placebo, and is well tolerated.     

Retinopathy of prematurity: causation

The incidence of ROP is birth weight dependent and restricting therapeutic oxygen levels has dramatically reduced the incidence of ROP in infants of birth weight >1000 g. However, the incidence of ROP has remained high in very low birth weight (VLBW) infants and this appears to be related to these babies being more ill. Several risk factors have been identified in this group, however oxygen variability, rather than high levels, has been correlated with severity of disease in recent clinical and animal studies. Difficulties in defining ‘normal’ oxygen in this group has meant the optimal range of oxygen therapy has not yet been defined. Clinical studies are now underway using even lower oxygen therapy ranges. The impact this may have on ROP, neurological and respiratory outcomes will require further study.     

Effect of zinc supplementation on growth in very low birth weight infants

This was a randomized blinded placebo controlled trial undertaken to study the role of zinc supplementation on growth, primarily the linear growth velocity in very low birth weight (VLBW) infants at 3 months corrected age (CA). Out of 134 neonates with birth weight <1500?g, 101 babies were eligible. Due to lack of consent 10 were excluded. The remaining 91 neonates who were comparable for sex, gestational age, birth weight, APGAR and age at enrollment were randomized to receive either 1?ml of zinc sulfate (10?mg elemental zinc) (n?=?46) or 1?ml placebo (n?=?45) from enrollment to 60 days. The infants in the zinc group had significantly higher linear growth velocity (0.98?±?0.12?cm?week(-1)) compared to a placebo group (0.67?±?0.15?cm?week(-1)) (p?相似文献   

Cerebral tissue oxygenation index and superior vena cava blood flow in the very low birth weight infant

Background: Superior vena cava (SVC) flow assesses blood flow from the upper body, including the brain. Near infrared spectroscopy (NIRS) provides information on brain perfusion and oxygenation.
Aim: To assess the relationship between cerebral tissue oxygenation index (cTOI) and cardiac output measures in the very low birth weight (VLBW) infant in the first day of life.
Methods: A prospective observational cohort study. Neonates with birth weight less than 1500 g (VLBW) were eligible for enrollment. Newborns with congenital heart disease, major congenital malformations and greater than Papile grade1 Intraventricular Haemorrhage on day 1 of life were excluded. Echocardiographic evaluation of SVC flow was performed in the first 24 h of life. Low SVC flow states were defined as a flow less than 40 mL/kg/min. cTOI was measured using NIRO 200 Hamamatsu.
Results: Twenty-seven VLBW neonates had both echocardiography and NIRS performed. The median (range) gestation was 29/40 (25 + 3 to 31 + 5 weeks) and median birth weight was 1.2 kg (0.57–1.48 kg). The mean (SD) TOI was 68.1 (7.9)%. The mean (SD) SVC flow was 70.36(39.5) mLs/kg/min. The correlation coefficient of cerebral tissue oxygenation and SVC flow was r = 0.53, p-value 0.005. There was a poor correlation between right and left ventricular output and cTOI which is not surprising considering the influence of intra- and extracardiac shunts.
Conclusion: There is a positive relationship between cerebral TOI values and SVC flow in the very low birth infant on day one of life.     

Fluconazole prophylaxis prevents invasive fungal infection in high-risk, very low birth weight infants

OBJECTIVES: To evaluate the benefit of fluconazole prophylaxis in preventing invasive fungal infection in very low birth weight (VLBW) infants with central vascular access. STUDY DESIGN: A 3-year baseline period (1998 to 2000) was compared with a subsequent 3-year period (2001 to 2003) during which a different protocol for preventing invasive fungal infection was used. All infants with a birth weight < 1500 g and with central vascular access were eligible for the study. Fluconazole (Diflucan R) was administered for 28 days at a dose of 6 mg/kg every third day during the first week and daily after the first week. RESULTS: There were no significant differences between the baseline and the fluconazole groups in demographic characteristics or risk factors for fungal infection. Fungal infection developed in 9 of the infants in the baseline group and in none of those in the fluconazole group (P=.003). A trend of decreasing mortality rate between the 2 groups (12.6% vs 8.1%; P=.32) was observed but was not statistically significant. No adverse effects of fluconazole therapy were documented. CONCLUSIONS: Fluconazole prophylaxis appeared to be beneficial in preventing invasive fungal infection in VLBW infants.     

Renal function and volume of infants born with a very low birth‐weight: a preliminary cross‐sectional study

Aim: The aim of our study was to compare the function and volumes of kidneys of very low birth‐weight (VLBW) and of extremely low birth‐weight (ELBW) infants at pre‐school ages. Patients and methods: We did a revision of the neonatal records of infants born in our hospital that weighed ≤1500 g at birth. The children were divided into two groups according to their weight at birth: ELBW (<1000 g) and VLBW (1000–1500 g). At the age of 5.7 ± 1.4 years, the children underwent clinical, laboratory and ultrasound renal assessments. Results: Sixty‐nine children fulfilled the requirements for the study. The rate of neonatal treatment with aminoglycosides was higher in ELBW preterms. Renal function parameters, i.e. estimated glomerular filtration rate and albuminuria, did not differ between the two groups of children. Urinary α1‐microglobulin excretion was significantly higher and kidneys were significantly smaller in the ELBW group than in the VLBW group. Conclusion: No impairment or differences in renal parameters were found in pre‐school children born ELBW compared with those born with VLBW, except for differences in kidney volume, renal cortical thickness and urinary α1‐microglobulin excretion. Thus, patients born with ELBW would require a longer follow‐up period.     

Pyrimethamine Teratogenesis by Short Term Administration in Goettingen Miniature Pig

Pyrimethamine was mixed with mashed feed and given to pregnant sows of Goettingen miniature pig through a part of the period of organogenesis. A high incidence of the major malformations such as cleft palate, club foot and micrognathia was observed in 13 out of 24 newborns from 5 pregnants which a teratogenic dose (3.6 mg/kg of body weight/day) from day 11 to day 22 of gestation, the first half of the organogenetic period. Only one cleft palate was observed among the 23 newborns from 4 pregnants administered the same dose through the second half of the period. Among the 51 newborns from 10 pregnants which the same dose through the first or second quarter, only 4 newborns showed external major malformations. However, 19 out of 38 live newborns without external major malformations in these groups died within 2 days after birth. Clinical symptoms of these neonatally dead young were similar to splayleg, a naturally occurring functional anomaly in pigs. No internal malformation was revealed by the autopsy of these dead newborns.     

Developmental Toxicity of Aspirin Prenatally Given to Rats: Assessment in Sic: Wistar-KY Rats

Abstract Slc:Wistar-KY rats were administered orally with 62.5, 125, 187.5 or 250 mg/kg aspirin suspended with 0.5 % CMC-Na on days 9–11 of gestation (plug += day 0). Suppression of maternal weight gain and food consumption during treatment was observed at and over 187.5 mg/kg. At term, the fetal mortality increased at and over 187.5 mg/kg and the fetal weight was lowered at and over 125 mg/kg. Among 15 live fetuses at 250 mg/kg, 4 had external malformations. In the skeletal examination (double staining), skeletal anomalies increased at and over 187.5 mg/kg. The skeletal variations such as vertebral anomalies, fused costal cartilages and increased presacral vertebrae were often encountered and delayed ossification was also found at and over 125 mg/kg. The internal anomalies tended to increase at and over 187.5 mg/kg. The live birth rate was significantly lower at 187.5 mg/kg than that in controls, and all pups, except for 3 from a dam, died before weaning. At 125 mg/kg, the pivoting locomotion on day 7 post partum was poorer as compared with controls. The physical and functional development at 62.5 mg/kg was not changed. There were no significant effects on male offspring in the open-field, rotarod, under-water T-maze and avoidance learning tests. However, in the Biel T-maze test (9–10 weeks of age), the aspirin-treated groups showed more errors and the increased elapsed time on the 1st trial day than controls. These results indicate that aspirin may induce a slight learning defect on rat offspring even at the non-teratogenic dose and the Biel T-maze test is more sensitive than any other learning tests given in this study.     

Midazolam sedation in mechanically ventilated newborns: a double blind randomized placebo controlled trial

OBJECTIVE: To determine efficacy of midazolam as a sedative in mechanically ventilated newborns. DESIGN: Double blind randomized placebo controlled trial. SETTING: Neonatal Unit of Tertiary Hospital. OUTCOME: Sedation over 48 h of observation. METHODS: Neonates with birth weight less than 2000 g who were mechanically ventilated within 7 days of life were randomly assigned to midazolam and placebo group. Midazolam and placebo were administered as bolus (0.2 mg/kg) followed by continuous infusion (0.06 mg/kg/h). Both groups received morphine infusion (10 microg/kg/h). Sedation score was noted at 6 hourly intervals for 48 hours. Hemodynamic variables, ventilatory variables, complications and side effects of treatments were also recorded. RESULTS: Thirty-three neonates were enrolled (17 in midazolam, 16 in placebo group). The groups were comparable for birth weights and gestation. The midazolam group had significantly better sedation from 18-24 hours after enrollment compared to placebo group. At 48 h there were no significant differences in proportion of infants with adequate sedation between midazolam and placebo group. The two groups were comparable with respect to heart rate, perfusion, ventilatory indices and blood gas parameters. None of the infants were noted to have hypotension on loading with midazolam or placebo. Seizures were noted in 2 neonates in placebo group 24 hours after enrollment (insignificant statistically). CONCLUSION: Sedation provided by continuous infusion of midazolam and morphine appears to be comparable to morphine alone in newborn babies on mechanical ventilation, with no significant adverse effects. The course of mechanical ventilation is not influenced by use of midazolam.     

Surfactant phosphatidylcholine composition during dexamethasone treatment in chronic lung disease

OBJECTIVES--To determine whether dexamethasone 'matures' the phosphatidylcholine (PC) composition of broncheoalveolar fluid in infants at high risk of neonatal chronic lung disease (CLD), either by increasing the proportion of dipalmitoylphosphatidylcholine (DPPC), expressed as a percentage of total PC (%DPPC), or by increasing the ratio of DPPC to palmitoyloleoylphosphatidylcholine (DPPC:POPC ratio). DESIGN--Double blind, placebo controlled. SETTING AND PATIENTS--Sixteen infants < 32 weeks' gestation, < 1250 g birth weight who were dependent on mechanical ventilation and requiring a fractional inspired oxygen of > 0.30 at 12 days of chronological age. INTERVENTION--Randomisation to receive a two week reducing course of dexamethasone base at an initial dose of 0.2 mg/kg three times a day, or equivalent volumes of normal saline, starting at 14 days. Eight infants were randomised into each group. Broncheoalveolar lavage was performed serially throughout the study period or until extubation. PC composition of the fluid was analysed by high performance liquid chromatography. OUTCOME MEASURES--The %DPPC and the DPPC:POPC ratios were calculated for individual infants for days -1 and 0 combined, days 1 and 3 combined, and days 5 and 7 combined. Analysis of covariance was used to analyse the results. RESULTS--The DPPC:POPC ratio was significantly less in the treated group than the placebo group on days 1 and 3, and not greater as the hypothesis stated. Three out of five infants treated with dexamethasone and for whom data were available showed a substantial rise in DPPC:POPC ratio on days 5/7, compared with the placebo group, but overall these changes were not statistically significant. CONCLUSIONS--The data do not support the hypothesis that dexamethasone's action in producing a clinical improvement within the first 72 hours of treatment for neonatal CLD is by the 'maturation' of pulmonary surfactant PC.