PEDIATRICS Vol. 117 No. 6 June 2006, pp. 2325 (doi:10.1542/peds.2006-0674)
Lucinactant Versus Poractant-
in Premature Lambs: In Reply
Adolf Valls-i-Soler, MD
Neonatal Intensive Care Unit
Elena Gastiasoro-Cuesta, MD
Francisco J. Alvarez-Diaz, PhD
Research Unit for Experimental Neonatal Respiratory Physiology,
Department of Pediatrics,
Hospital Cruces,
University of the Basque Country,
Barakaldo E-48903, Bizkaia, Spain
We thank Drs Halliday and Speer for their interest in our recent Pediatrics article.1 They expressed their surprise about our abstract, because they felt that it did not reflect the main findings of our experiments.
First, we apologize for an error that escaped editing. Line 18 of the abstract reads "PaCO2: 8 ± 18 mmHg," but the correct value is "48 ± 18 mmHg."
Although higher PaO2 levels were noted in the poractant-
group than in the lucinactant group in the first 6 hours, differences did not reach statistical significance at any time-point interval of the study. Moreover, mean PaO2 values included those of lambs that did not respond to surfactant: 33% in the lucinactant group.
The conclusion that "lucinactant produced improvements in gas exchange and lung mechanics similar to those observed with a porcine-derived surfactant" is supported by the fact that there were no statistical differences in arterial pH, PaO2, PaCO2, tidal volume, airway resistance, dynamic compliance, and C20 as a measure of lung overdistention, but there was in mean airway pressure. Furthermore, after 12 hours of surfactant instillation, indices that combine arterial oxygenation and ventilatory pressures, such as oxygenation index and ventilatory efficacy index, were also similar.
We agree that results could have been described with greater detail in the abstract, but space limitations precluded it. Furthermore, we thought that results reflecting the overall and final status of lambs in this 12-hour experiment should be stressed in the abstract. That possibly is the reason why the referees did not perceive clinically significant differences between the specific findings in the manuscript and our final conclusions in the abstract.
It should also be considered that, to our knowledge, a quick initial oxygenation response after surfactant instillation has not been clinically related to improvements on any long-term outcome. In fact, a rapid increase in oxygenation could have negative consequences, because it suddenly decreases pulmonary vascular resistance and cerebral blood flow.2,3
Finally, it should be stressed that readers must always read beyond the abstract to understand the specific findings of any study.
FOOTNOTES
Financial Disclosure: We too freely declare potential conflict of interest, because we received support from Discovery and Esteve Laboratories to perform these experiments, but we have also received support from Chiesi, for basic and for clinical studies as well as consultancy fees.
REFERENCES
- Gastiasoro-Cuesta E, Alvarez-Diaz FJ, Rey-Santano C, Arnaiz-Renedo A, Loureiro-Gonzalez B, Valls-i-Soler A. Acute and sustained effects of lucinactant versus poractant- on pulmonary gas exchange and mechanics in premature lambs with respiratory distress syndrome.
Pediatrics. 2006;117
:295
–303
[Abstract/Free Full Text] - Cowan F, Whitelaw A, Wertheim D, Silverman M. Cerebral blood flow velocity changes after rapid administration of surfactant. Arch Dis Child. 1992;66 :1105 –1109
- Murdoch E, Kempley ST. Randomized trial examining cerebral haemodynamics following artificial or animal surfactant. Acta Paediatr. 1998;87 :411 –415[CrossRef][Web of Science][Medline]
PEDIATRICS (ISSN 1098-4275). ©2006 by the American Academy of Pediatrics
CiteULike 
Connotea 
Del.icio.us 
Digg 
Facebook 
Reddit 
Technorati 
Twitter What's this?
Related articles in Pediatrics:
- Lucinactant Versus Poractant- in Premature Lambs
- Henry L. Halliday and Christian P. Speer
Pediatrics 2006 117: 2324-2325.[Extract] [Full Text]
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
