Dear Editor

Frey and Shann have described different methods of administering oxygen with their pros and cons[1] : There is one more option available, although less-known and less tried, i.e., oropharyngeal administration of oxygen.[2] Head box oxygen is wasteful, hence uneconomical. Face mask is difficult to keep in place in children. Nasal prongs are expensive and are not available universally. Nasopharyngeal catheters tend to get blocked leading to hypoxia and deaths.[3] Nasal catheters may lead to ulcerations and bleeding besides getting blocked.[4] Secondly, unilateral nasal occlusion by a mere passage of a tube like, nasal or nasopharyngeal catheter, is expected to cause airway compromise.[5,6] Oropharyngeal oxygen administration is low flow method. Universally available feeding tubes which are also cheap were used for this purpose. Blockage of tube was not a problem possibly because oropharyngeal secretions are thinner compared to nasal or nasopharyngeal secretions.

References

(1) Frey B, Shann F. Oxygen administration in infants. Arch Dis Child, Fetal and Neonatal Edition 2003:88: F84-88.

(2) Daga SR, Verma B, Gosavi DV. Oropharyngeal delivery of oxygen to children. Trop Doct 1999: 29: 98-99.

(3) Weber MW, Palmer A, Oparango A, Mullholland EK. Comparison of nasal prongs and nasopharyngeal catheter for delivery of oxygen in children with hypoxemia because of a lower respiratory tract infection. J Pediatr 1995: 127: 378-383.

(4) Muhe L, Degefu H, Worku B, Birhane O, Mullholland EK. Ann Trop Pedia 1997;17: 273-281.

(5) Martin RJ, Miller MJ, Siner B, Difiore JM, Carlo WA. Effects of unilateral nasal occlusion on ventilation and pulmonary resistance in infants. J Appl Physiol 1989; 66: 2522-6.

(6) Stocks J. Effects of nasogastric tube on nasal resistance during infancy. Arch Dis Child 1980: 55: 17-2.

Dear Editor

We were interested to see the article “Oxygen Administration in Infants” [1], and subsequent e-letter responses. Both the original article and e-letters were unsure of the efficacy of “non-contact” oxygen delivery, or “wafting” as it is more commonly known. We would like to refer to our study “The Efficacy of Non-Contact Oxygen Delivery Systems”[2] which demonstrated how effective wafting oxygen can be. We found an area of 34 by 37cm obtains a concentration of >30% when oxygen is delivered by face mask at 10 litres/minute. Although this cannot be a substitution for the more reliable methods of administration as detailed by Drs Frey and Shann, in the short term it can be used with confidence.

We caution that holding a self-inflating resuscitation bag over an infant’s airway (without any manipulation of the bag itself), as is often the practice in neonatal delivery rooms, delivers a negligible amount of oxygen. It is much more efficacious to use the oxygen tubing without any attachments.

Yours sincerely

Dr Patrick Davies
Dr Danny Cheng
Dr Adam Fox
Dr LLeona Lee

References

(1) Oxygen administration in infants. B Frey and F Shann. Arch. Dis. Child. Fetal Neonatal Ed. 2003; 88: F84-F88

(2) The Efficacy of Non Contact Oxygen Delivery Systems. Davies P, Cheng D, Fox A, Lee L. Pediatrics. 2002 Nov;110(5):964-7

Dear Editor

Oxygenation by head box is a very useful method as highlighted by the authors of the article.[1] However, there are some issues which need deliberation on head box. The disturbance of oxygen enriched environment may occur during routine care procedures like feeding & suctioning. A newer head box developed by Jain MM et al, provides facility of feeding & other nursing care with out affecting the oxygen environment.[2]

The CO₂ retention in the head box is a likely possibility with low oxygen flow rates, however, as mentioned in the study & by research of Jain MM et al,[2] there was no retention of CO₂ at oxygen flow rate of even 1 litre/mt. These observations should not be taken as practice guidelines because of the lack of statistical strength of studies. As the head box device is a high oxygen flow device, it is better to run it with Oxygen flow rates of >5 litres/mt, which will ensure proper oxygen delivery to the patient as well minimize the probability of CO₂ rebreathing. The difficulty comes when one has to wean the oxygen therapy by hood. Then weaning must be done not by reducing the oxygen flow rates but by permitting more air & oxygen admixture by opening more number of port holes, increasing the shutter opening & by moving the head box slowly & progressively in a stepped manner upwards. Lack of appropriate attention to the above statement may compromise usefulness of headbox with respect to O₂ & CO₂ .

It is correct that natural functions of nose of humidification and warming are available to the patient when O₂ 2 is given by headbox. Practically, one realizes that if one does not use humidifier with warming facility, then the cold & humidified oxygen will be delivered to a neonate because of the standard prevailing routine practice of passing the oxygen through Wolf bottle (bubble humidification), in most of the countries of the world. Therefore, a neonate with respiratory disease may deteriorate to whatever little extent because of irritant effect of cold O₂. Hence, it will be good clinical practice to use warm & humidified oxygen even through headbox. Oxygen administration by holding an oxygen source near the infant’s face: This kind of oxygen administration is widely used for short periods. Owing to the dilutional effects of ambient air, the effective FIO₂ may be low and is unpredictable. However, to provide better oxygenation one can also use a practical technique of making the cup with one’s own hand and let the oxygen pass through the hand from the tubing coming close to the neonate’s face from oxygen source. This is a good tried technique for short period of oxygenation.

The above mentioned remarks are made to facilitate correct bedside clinical practices. The authors requested to give their response.

References

(1) Frey B , Shann F. Oxygen administration in infants. Arch Dis Child Fetal and Neonatal Ed 2003;88:F84.

(2)Jain MM, Shenoi A, Paramesh H. A New Oxygen Head Box. Indian Pediatrics 2002; 39:842-846.