Carnitine deficiency in preterm infants: A national survey of knowledge and practices.

OBJECTIVE: Lipid supplementation improves developmental outcomes in preterm infants. Carnitine is essential for lipid metabolism; however, despite high risk for carnitine deficiency, there are no standards for carnitine supplementation in preterm infants receiving total parenteral nutrition (TPN). Our objective was to assess knowledge, beliefs and practices regarding preterm carnitine deficiency and supplementation among neonatal practitioners. METHODS: Cross-sectional electronic survey administered via a nationally representative listserv of neonatal practitioners. RESULTS: 492 respondents participated in the survey. Only 21% of respondents were aware that carnitine is secreted by the placenta. 72% believed that carnitine deficiency was common, and 60% believed deficiency could have serious consequences. Five percent routinely screened for deficiency, and 40% routinely provided carnitine supplementation. Respondents with >5 years' experience were more likely to report using carnitine supplementation (50% vs. 38%). CONCLUSIONS: Although most respondents believed that carnitine deficiency is common and could have serious consequences, few screened for deficiency and fewer than half routinely supplemented. Thus, many preterm infants remain at risk for carnitine deficiency. Further research is needed to elucidate the risks of carnitine deficiency in these vulnerable infants.

Predictors of successful closure of patent ductus arteriosus with indomethacin.

OBJECTIVE: To determine whether platelet counts can predict the likelihood of successful closure of patent ductus arteriosus (PDA) with indomethacin. STUDY DESIGN: This was a retrospective cohort study of infants <32 weeks' gestational age (GA) and birth weight <1500 g with PDA. Clinical characteristics between infants who achieved ductal closure with indomethacin and those who failed were compared. Multivariable logistic regression was used to identify predictors of successful ductal closure. RESULTS: In infants with hemodynamically significant PDA, older GA (odds ratio=1.54; 95% confidence interval: 1.12 to 2.13), male gender (odds ratio=3.02; 95% confidence interval: 1.08 to 8.49) and higher platelet count (odds ratio=1.5; 95% confidence interval: 1.04 to 2.17) prior to indomethacin treatment were associated with successful ductal closure with indomethacin. CONCLUSION: Older GA, male gender and higher platelet count at time of treatment of hemodynamically significant PDA are predictors of successful ductal closure with indomethacin.

Evaluating the efficacy of mucoactive aerosol therapy.

The aerosol route is attractive for the delivery of mucoactive medications. Mucoactive medications include mucolytics, which depolymerize polymers of mucin (classic mucolytics) or DNA/actin (peptide mucolytics), mucokinetic agents, which increase cough clearance, mucoregulatory medications, which decrease abnormal mucus secretion, and expectorants and ion channel modifiers. Despite the widespread use of these medications, there are few well conducted studies and thus few data clearly supporting (or failing to support) their use. This will change as our understanding of mucociliary physiology and pharmacology increases and as well designed and well powered clinical trials are conducted with appropriate outcome measurements. Effective mucoactive therapy should make a profound impact on the care of patients with chronic bronchitis, asthma, cystic fibrosis, and inflammatory airways disease, and will be essential for the effective delivery of gene therapy vectors and bioactive peptides to the airway epithelium.

Gastroesophageal reflux in very low birth weight infants: association with chronic lung disease and outcomes through 1 year of age.

OBJECTIVE: To analyze the association between chronic lung disease (CLD) and clinically diagnosed gastroesophageal reflux (GER) in very low birth weight (VLBW) infants, and between GER and outcomes at 1 year adjusted age. METHODS: A total of 375 consecutively born VLBW infants with CLD and 345 gestational age-matched controls were studied. Records were reviewed to ascertain which infants were diagnosed with GER (based on clinical suspicion or confirmatory tests) and which infants had delayed growth or development at 1 year adjusted age. RESULTS: Infants with CLD were treated for GER more frequently than controls (CLD: 27% versus controls: 9%; p < 0.0001). Among infants with CLD, those with and without GER were comparable in terms of the days on supplemental oxygen [124 (64 to 93) vs 121 (47 to 394)] and the proportion with cystic changes on chest radiograph (44% vs 47%). Comparing outcomes at 1 year for infants with and without GER, no differences were found in the rates of Bayley Mental Developmental and Psychomotor Developmental Indices of < 70, cerebral palsy, and measurements below the 10th percentile. CONCLUSION: Among VLBW infants, an association exists between CLD and GER, although this association might be due to greater diagnostic suspicion in infants with CLD. In VLBW infants, GER does not appear to increase the risk of delayed growth or development.

Management of meconium-stained amniotic fluid.

Meconium staining of the amniotic fluid will always be a common problem. Although several therapies may be of benefit in preventing MAS, most require further rigorous scientific investigation to assess their potential in preventing this disorder.

Effect of flow rate and insulin priming on the recovery of insulin from microbore infusion tubing.

BACKGROUND: A retrospective medical record review of 13 consecutive, hyperglycemic, extremely low birth weight (ELBW) infants treated with continuous insulin infusions revealed a 14- to 24-hour delay (mean, 19 hours) in blood glucose normalization despite stepwise increases in insulin infusion rates. OBJECTIVE: This in vitro study examined the effects of flow rate and insulin priming on insulin recovery from polyvinyl chloride (PVC) tubing and polyethylene (PE)-lined PVC tubing infused with a standard insulin stock solution. METHODS: Stock insulin solution (0.2 U/mL) was infused through microbore PVC or PE-lined tubing at flow rates of 0.05 and 0.2 mL/h. To determine if saturation of nonspecific binding sites would alter effluent insulin concentration, we compared insulin recovery from tubing previously flushed with the stock solution and tubing primed with 5 U/mL of insulin for 20 minutes. Effluent samples, which were collected at baseline and at six time points during a 24-hour period, were immediately frozen at -20 degreesC. Insulin concentration was measured by IMx immunoassay. Data were analyzed using general linear modeling with repeated measures. RESULTS: At 0.05 mL/h flow rate, insulin recovery from unprimed PVC tubing at 1, 2, 4, and 8 hours was 17%, 11%, 27%, and 55%, respectively, with 100% recovery at 24 hours. From insulin-primed tubing, insulin recovery was approximately 70% at 1, 2, and 4 hours, and close to 100% at 8 hours. At a faster flow rate of 0.2 mL/h, insulin recovery at 1, 2, 4, and 8 hours was 22%, 38%, 67%, and 75% vs 42%, 85%, 91% and 95% from unprimed and insulin-primed PVC tubing, respectively. Similar results were obtained from unprimed and insulin-primed PE-lined tubing at 0.2 mL/h flow rate. CONCLUSIONS: Priming of microbore tubing with 5 U/mL of insulin solution for 20 minutes to block nonspecific binding sites enhances delivery of a standard insulin stock at infusion rates typically used to treat hyperglycemic ELBW infants. We conclude that priming the tubing with a higher concentration of insulin before initiation of standard insulin infusion therapy should accelerate achievement of steady-state insulin delivery and correction of hyperglycemia in ELBW infants.