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Hypoxemia following inhalation of helium-oxygen
392
Editorial correspondence
In our experience, high serum AFP levels may be present in the first year of life in some, but not all, infants with WBS. Further cooperative and prospective studies are necessary to confirm our findings and, eventually, to ascertain in how many and in which newborn infants with WBS high serum AFP levels may occur. Longitudinal follow-up in patients with WBS and normal or high AFP levels appears warranted. Luigi Pavanello, M.D. Gianfranco Rizzoni, M.D. Barbara Andreetta, M.D. Graziella Zacchello, M.D. Giovanna Largaiolli, M.D. Department of Pediatrics University of Padua Via Giustiniani 3 35100 Padua, Italy
The Journal of Pediatrics August 1986
rabbits subjected to bilateral cervical vagotomy were given oxygen in binary mixture with each of the gases. Helium was used with 20% and 60% oxygen. Within several hours of use, survival was shorter and pulmonary injury four times greater in the helium exposed animals with 20% oxygen compared with similar percentage oxygen in combination with nitrogen. Helium in 40% concentration with 60% oxygen was associated with hepatization of lung tissue 25% greater than in similar concentration of oxygen with nitrogen. The authors concluded that oxygen is inherently toxic to the lung and that helium increases the toxicity. Samuel DuBose Ravenel, M.D. Moses H. Cone Memorial Hospital 1200 N. Elm St. Greensboro, NC 27401-1020 REFERENCES
I.
REFERENCES
1. Sotelo-Avila C, Gonzales-Crussi F, Fowler JW. Complete and incomplete forms of Beckwith-Wiedemann syndrome: their oncogenic potential. J P~OIATR 1980;96:47. 2. Wiedemann HR. Tumors and hemihypertrophy associated with Wiedemann-Beckwith syndrome. Eur J Pediatr 1983; 141:129. 3. Lau LH, Linkins SE. Alpha-fetoprotein. Am J Obstet Gynecol 1976;124:553. 4. Brown N J, Goldie DJ. Beckwith's syndrome with renal neoplasia and alpha-fetoprotein secretion. Arch Dis Child 1978;53:435.
Hypoxemia following inhalation of helium-oxygen To the Editor: Butt et al. ~ reported unexpected hypoxemia in six infants following the use of helium-oxygen inhalation after extubation during management of bronchopulmonary dysplasia with subglottic stenosis. They suggest that use of continuous positive airway pressure (CPAP) concomitantly with helium-oxygen might prevent hypoxemia. Hypoxemia following use of helium-oxygen has been reported previously, and another earlier report suggests that helium-oxygen inhalation in the neonatal period may cause or aggravate pulmonary oxygen toxicity, especially in situations in which oxygen toxicity is likely to have a role in pulmonary disease, such as bronchopulmonary dysplasia. Tatsuno et a13 reported experience with the use of heliumoxygen and CPAP via endotracheal tube in weaning 11 infants and young children from mechanical ventilation. In seven patients they observed an increase in Pao2 during the first few hours of helium-oxygen, with a significant decrease in Pao2 from the second day and after. In two additional patients hypoxemia was encountered immediately on changing from mechanical ventilation to helium-oxygen with CPAP. Shanklin and Leste# reported the results of a study on the role of nitrogen as a second gas compared with helium, neon, argon, and sulfur hexafluoride in combination with oxygen. Newborn
Butt WW, Koren G, England S, et al. Hypoxia associated with helium-oxygen therapy in neonates. J PetnATR 1985; 106:474. 2. Tatsuno K, Imai Y, Konno S. Therapeutic use of heliumoxygen mixture in continuous positive airway pressure for early weaning from mechanical ventilation after cardiovascular surgery in infants. J Thorac Cardiovasc Surg 1976;72:119. 3. Shanklin DR, Lester EP. On the pulmonary toxicity of oxygen. Biol Neonate 1972;20:140.
Reply To the Editor: We thank Dr. Ravenel for drawing our attention to additional data supporting our observations. Our study followed a report in the JournaP that suggested advantage of helium-oxygen inhalation in neonates. Moreover, similar results were reported in older children and adults? 3 At the outset, the tlaeoretical advantage of helium in reducing friction and cost of breathing appeared conceivable; however, careful assessment revealed helium-associated hypoxemia, which could be prevented by CPAP. The data quoted by Dr. Ravenel certainly strengthen our caution that the potential advantages of helium-oxygen inhalation may be outweighted by hypoxemia. Although we do not believe that animal studies can be directly extrapolated to the different setting of ventilation in the neonate, they certainly indicate that more research is needed. It is conceivable, for instance, that the neonatal mice exposed to helium might not have died if CPAP was introduced. Gideon Koren, M.D. ]Veil Shear, M.D. Division of Clinical Pharmacology The Hospital for Sick Children 555 University Ave. Toronto, Ontario, Canada M5G I)(8 REFERENCES
1. Wolfson MR, Bhutani UK, Shaffer TH, Bowen FW Jr. Mechanics and energetics of breathing helium in infants
Editorial correspondence
In our experience, high serum AFP levels may be present in the first year of life in some, but not all, infants with WBS. Further cooperative and prospective studies are necessary to confirm our findings and, eventually, to ascertain in how many and in which newborn infants with WBS high serum AFP levels may occur. Longitudinal follow-up in patients with WBS and normal or high AFP levels appears warranted. Luigi Pavanello, M.D. Gianfranco Rizzoni, M.D. Barbara Andreetta, M.D. Graziella Zacchello, M.D. Giovanna Largaiolli, M.D. Department of Pediatrics University of Padua Via Giustiniani 3 35100 Padua, Italy
The Journal of Pediatrics August 1986
rabbits subjected to bilateral cervical vagotomy were given oxygen in binary mixture with each of the gases. Helium was used with 20% and 60% oxygen. Within several hours of use, survival was shorter and pulmonary injury four times greater in the helium exposed animals with 20% oxygen compared with similar percentage oxygen in combination with nitrogen. Helium in 40% concentration with 60% oxygen was associated with hepatization of lung tissue 25% greater than in similar concentration of oxygen with nitrogen. The authors concluded that oxygen is inherently toxic to the lung and that helium increases the toxicity. Samuel DuBose Ravenel, M.D. Moses H. Cone Memorial Hospital 1200 N. Elm St. Greensboro, NC 27401-1020 REFERENCES
I.
REFERENCES
1. Sotelo-Avila C, Gonzales-Crussi F, Fowler JW. Complete and incomplete forms of Beckwith-Wiedemann syndrome: their oncogenic potential. J P~OIATR 1980;96:47. 2. Wiedemann HR. Tumors and hemihypertrophy associated with Wiedemann-Beckwith syndrome. Eur J Pediatr 1983; 141:129. 3. Lau LH, Linkins SE. Alpha-fetoprotein. Am J Obstet Gynecol 1976;124:553. 4. Brown N J, Goldie DJ. Beckwith's syndrome with renal neoplasia and alpha-fetoprotein secretion. Arch Dis Child 1978;53:435.
Hypoxemia following inhalation of helium-oxygen To the Editor: Butt et al. ~ reported unexpected hypoxemia in six infants following the use of helium-oxygen inhalation after extubation during management of bronchopulmonary dysplasia with subglottic stenosis. They suggest that use of continuous positive airway pressure (CPAP) concomitantly with helium-oxygen might prevent hypoxemia. Hypoxemia following use of helium-oxygen has been reported previously, and another earlier report suggests that helium-oxygen inhalation in the neonatal period may cause or aggravate pulmonary oxygen toxicity, especially in situations in which oxygen toxicity is likely to have a role in pulmonary disease, such as bronchopulmonary dysplasia. Tatsuno et a13 reported experience with the use of heliumoxygen and CPAP via endotracheal tube in weaning 11 infants and young children from mechanical ventilation. In seven patients they observed an increase in Pao2 during the first few hours of helium-oxygen, with a significant decrease in Pao2 from the second day and after. In two additional patients hypoxemia was encountered immediately on changing from mechanical ventilation to helium-oxygen with CPAP. Shanklin and Leste# reported the results of a study on the role of nitrogen as a second gas compared with helium, neon, argon, and sulfur hexafluoride in combination with oxygen. Newborn
Butt WW, Koren G, England S, et al. Hypoxia associated with helium-oxygen therapy in neonates. J PetnATR 1985; 106:474. 2. Tatsuno K, Imai Y, Konno S. Therapeutic use of heliumoxygen mixture in continuous positive airway pressure for early weaning from mechanical ventilation after cardiovascular surgery in infants. J Thorac Cardiovasc Surg 1976;72:119. 3. Shanklin DR, Lester EP. On the pulmonary toxicity of oxygen. Biol Neonate 1972;20:140.
Reply To the Editor: We thank Dr. Ravenel for drawing our attention to additional data supporting our observations. Our study followed a report in the JournaP that suggested advantage of helium-oxygen inhalation in neonates. Moreover, similar results were reported in older children and adults? 3 At the outset, the tlaeoretical advantage of helium in reducing friction and cost of breathing appeared conceivable; however, careful assessment revealed helium-associated hypoxemia, which could be prevented by CPAP. The data quoted by Dr. Ravenel certainly strengthen our caution that the potential advantages of helium-oxygen inhalation may be outweighted by hypoxemia. Although we do not believe that animal studies can be directly extrapolated to the different setting of ventilation in the neonate, they certainly indicate that more research is needed. It is conceivable, for instance, that the neonatal mice exposed to helium might not have died if CPAP was introduced. Gideon Koren, M.D. ]Veil Shear, M.D. Division of Clinical Pharmacology The Hospital for Sick Children 555 University Ave. Toronto, Ontario, Canada M5G I)(8 REFERENCES
1. Wolfson MR, Bhutani UK, Shaffer TH, Bowen FW Jr. Mechanics and energetics of breathing helium in infants