January 2012

New Year’s Resolution: Update Your Profile Page on AARConnect!

Here’s a great New Year’s resolution we’re hoping everyone in our section will fulfill before the end of the month—go to AARConnect and complete your profile information and upload a photo of yourself to your profile page. All you have to do to get started is log in with your AARC membership number and then click on “Complete your profile” in the box in the upper right hand corner that welcomes you to the site. Just follow the prompts from there to add as much (or as little) information as you’d like and a photo!

Antenatal Steroids Benefit Smallest Preemies

Antenatal steroids can improve outcomes for premature infants born at 23–25 weeks gestational age, report U.S. researchers publishing in the Dec. 7 edition of JAMA. Their study was conducted among more than 10,000 infants born at 22–25 weeks gestation at 23 academic perinatal centers. Among this group, 74.1% were born to mothers who received antenatal corticosteroids. Neurodevelopmental assessments were conducted in 86.5% of the 5691 infants who survived to 18–22 months. Results showed infants who received antenatal steroids had less neurodevelopmental impairment than infants who did not, 83.4% vs. 90.5%, respectively, at 23 weeks; 68.4% vs. 80.3% at 24 weeks; and 52.7% vs. 67.9% at 25 weeks. No significant difference was seen for infants born at 22 weeks (90.2% vs. 93.1%, respectively). Death by 18–22 months, hospital death, intraventricular hemorrhage or periventricular leukomalacia, and necrotizing enterocolitis were also less frequent for infants born between 23–25 weeks gestation who received antenatal steroids. The only outcomes that were improved for infants born at 22 weeks were death and necrotizing enterocolitis. “Initiation of antenatal corticosteroids may be considered starting at 23 weeks’ gestation and later if the infant will be given intensive care because this therapy is associated with reduced mortality and morbidity,” conclude the authors. READ PRESS RELEASE

Inhaled Mannitol Found Effective in CF

Inhaled mannitol 400 mg bid improved lung function over the long term for patients with cystic fibrosis in a new study conducted by investigators from Seattle, WA. They compared 192 patients who received the treatment with 126 others in a control group. The 26 week double-blind, randomized trial was followed by 26 weeks of open-label treatment. A mean improvement in FEV1 of 105 mL (8.2% above baseline) was seen in the treatment group, and this group also had a relative improvement in FEV1 of 3.75% when compared to the control group. FEV1 was maintained in the original treatment group, and improved in the original control group to the same degree, during the 26 week open-label portion of the trial. Adverse events, sputum microbiology, and exacerbations rates were similar. The study was published ahead of print by the American Journal of Respiratory and Critical Care Medicine on Dec. 23. READ ABSTRACT

Bench Study Questions Conventional Physiology

Brown University researchers who conducted a bench study using an end-tidal CO2 monitor to measure the time to wash out CO2 from a 45-ml test lung find that, contrary to conventional physiology, effective CO2 elimination appears possible with tidal volume (VT) less than dead space (DS), even at conventional rates. Among the results:

• Halving the theoretical “alveolar ventilation” (DS+2 ml to DS+1 ml) only increased the elimination time by 26%, not the 100% predicted by conventional physiology.
• CO2 washout was less efficient, but still occurred even at VT=DS and VT=DS-1.5 ml.
• Halving the theoretical “alveolar ventilation” by decreasing the respiratory rate from 80 to 40 breaths/min only increased elimination time by 35%, not 100%, as predicted by conventional physiology.
• Twenty minutes of CPAP prior to ventilation did not alter the elimination time, verifying that CO2 did not diffuse or leak out of the test lung.
• Size of the endotracheal tube (ETT 2.5, 3.0, and 3.5 mm), flow rate (4, 6, and 10 l/min), and inspiratory time (0.25 vs. 0.35 s) did not affect the results.

“With small ETT a spike of fresh gas likely penetrates through the DS, rather than pushing it ahead,” explain the authors. The study was published ahead of print by the Archives of Disease in Childhood: Fetal and Neonatal Edition on Nov. 18. READ ABSTRACT

Study Sheds Light on Role of Prolonged Inflation Time During Neonatal Resuscitation

A new study from British researchers is helping to clarify the effects of prolonged inflation time during resuscitation on premature infants. Noting one previous study showed no effect while another suggested a reduction in brochopulmonary dysplasia, these investigators assessed the length of inflation times used during face mask and t-piece resuscitation of 40 premature infants born at a mean gestational age of 30 weeks to determine whether prolonged inflations lead to longer inflation flow times. Flow, airway pressure, and tidal volume changes were recorded for the first five inflations using a respiration monitor. The median inflation pressure was 17.6 cmH2O, inflation time was 0.89 seconds, expiratory tidal volume was 1.01 ml/kg, and inflation flow time was 0.11 seconds. While no significant relationship was seen between the inflation time and the inflation flow time, the researchers did note a significant relationship between the inflation pressure and the inflation flow time. They conclude, “These results suggest that prolonging inflation times during face mask resuscitation of prematurely born infants would not improve ventilation as prolonged inflation did not lead to longer inflation flow times.” The study was published ahead of print by the European Journal of Pediatrics on Dec. 28. READ ABSTRACT

Poorer Outcomes Seen for Preemies who are Small for Gestational Age

Infants who are born at less than 33 weeks gestation and have a birthweight less than the 10th percentile for gestational age and sex have poorer outcomes that similar infants who are not small for gestational age. That’s the take home message from Canadian researchers who compared outcomes for small for gestational age (SGA) infants with non-small for gestational age (non-SGA) infants in a large database. SGA infants had higher major morbidity and mortality rates and were more likely to suffer from necrotizing enterocolitis, bronchopulmonary dysplasia, severe retinopathy of prematurity, and respiratory distress syndrome. They also had more prolonged stays in the NICU, longer use of CPAP and supplemental oxygen, and higher resource utilization. The study was published ahead of print by the American Journal of Perinatology on Nov. 30. READ ABSTRACT