Physiologic implications of helium as a carrier gas for inhaled nitric oxide in a neonatal model of Bethanecol-induced bronchoconstriction.

OBJECTIVE: To compare heliox to nitrogen-oxygen (nitrox) as a carrier gas for inducible nitric oxide (iNO) in the presence of pharmacologically inhaled bronchoconstriction. We hypothesized that respiratory resistance and gas exchange would improve when iNO is delivered with heliox. DESIGN: Interventional laboratory study. SETTING: An academic medical research facility in the northeastern United States. SUBJECTS: Sedated, ventilated newborn piglets. INTERVENTIONS: Newborn piglets (n = 16; 2.3 +/- 0.1 kg) were placed on a flow-controlled ventilator and given intravenous Bethanecol (2 x 1 mg/kg followed by 1 mg/kg/hr) to induce bronchoconstriction. Piglets were randomized to heliox or nitrox (Fio2 = 0.3) and given 80 ppm iNO. MEASUREMENTS AND MAIN RESULTS: Hemodynamics, blood chemistry, and pulmonary mechanics were recorded at 30-min intervals for 2 hrs. Bethanecol dosing increased inspiratory respiratory resistance (cm H2O/L/min; p < .01) and decreased respiratory compliance (mL/cm H2O/kg; p < .01). Following carrier gas assignment, hemodynamics and respiratory compliance were similar between groups and respiratory resistance decreased (p < .01) in the heliox group. Over 2 hrs with iNO therapy, Paco2 increased (p < .01) whereas blood pH decreased (p < .01) in the heliox group. Respiratory resistance trended downward, oxygenation index improved (p < .01), and blood methemoglobin levels trended higher for nitrox compared with heliox. CONCLUSIONS: The INOvent was effective for controlling heliox delivery of iNO. Despite marked reduction in respiratory resistance with heliox gas ventilation in a neonatal model of pharmacologic bronchoconstriction, nitrox might perform better as a delivery vehicle for iNO.

Parental preferences regarding administration of an animal-derived versus a synthetic medication to newborn infants.

AIM: We examined the perceptions of parents with regard to animal-derived versus synthetic medications of comparable efficacy. We hypothesized that this issue is a concern in neonatal care and that the perceptions of parents from one geographical location would be similar to those of another. METHODS: A survey was distributed to parents of neonates admitted to a neonatal intensive care unit of a southeastern hospital. RESULTS: Of 153 parents surveyed, 150 (98%) responded. More mothers than fathers completed the surveys (113 vs. 34). Fifty-six percent of participants indicated a college or higher education; 40% had an income of $51,000/yr or higher. Thirty-four percent of parents had concerns about animal-derived medications, 41% preferred a synthetic medication of equivalent efficacy, and 69% would like to be informed if a medication was animal-derived. CONCLUSION: Parents have concerns about exposing neonates to animal-derived medication and wish to be informed if an animal-derived medication is being considered.