Retrolental fibroplasia

Treatment needs to be adjusted

EDITOR--The results of the audit of oxygen prescribing by Dodd et al raise numerous issues.[1] The audit focused solely on the prescribed input rather than a measure of outcome. No reference was made to adjusting treatment with regard to the patient's oxygen saturation.[2] Realistic goals for desired saturation would reduce the risks of either continued hypoxia or excessive treatment in severe chronic obstructive pulmonary disease.

The spectre of carbon dioxide narcosis was again raised. Intensivists repeatedly find that seriously hypoxic and exhausted patients have had their oxygen treatment reduced because of a raised arterial concentration of carbon dioxide.[3] Guidelines issued by the British Thoracic Society for the management of chronic obstructive pulmonary disease state that the aim of initial treatment is to raise the arterial oxygen concentrations (to [is greater than or equal to] 6.6 kPa) and that a fall in arterial pH to less than 7.26 (equivalent to a hydrogen ion concentration of 54 nmol/l) gives cause for concern.[4] The main focus is not on concentrations of carbon dioxide.

A few patients require careful titration of oxygen treatment, but the current widespread assumption that everyone with a diagnosis of chronic obstructive pulmonary disease should therefore have their oxygen treatment drastically restricted is dangerous. Where there is a suspicion of a retention of carbon dioxide, further history should be sought to avoid increasing hypoxia in an already exhausted patient.

Andrew Inglis consultant intensivist Southern General Hospital, Glasgow G51 4TF

[1] Dodd ME, Kellet F, Davis A, Simpson JCG, Webb AK, Haworth CS, et al. Audit of oxygen prescribing before and after the introduction of a prescription chart BMJ 2000;321:864-5. (7 October.)

[2] Bateman NT, Leach RM. Acute oxygen therapy. BMJ 1998;317:1798-801.

[3] Lavery GG. Fear of hypercapnia is leading to inadequate oxygen treatment. BMJ 1999;318:872.

[4] COPD Guidelines Group, Standards of Care Committee BTS. Management of acute exacerbations of COPD. Thorax 1997;52: S16-21.

Oxygen prescribing has implications in neonatal care

EDITOR--As paediatricians we acknowledge the important points introduced by Dodd et al in their audit of oxygen prescribing and the use of an oxygen prescription chart.[1] There have been no randomised controlled trials of oxygen treatment in infants, and most of our practice is based on observational studies.[2] Many paediatric units do not prescribe oxygen on a formal chart such as the one suggested. Preterm infants and older babies with chronic lung disease require precise oxygen treatment, and the method of prescribing oxygen to these infants should be urgently reviewed in light of this audit.

There are potential hazards of inaccurate prescribing and administration of oxygen in neonatal care. Oxygen treatment in ventilated preterm infants must be closely monitored to reduce the incidence of potentially blinding retinopathy of prematurity.[3] Furthermore, it has been shown that adequate oxygen treatment in babies with chronic lung disease helps prevent pulmonary hypertension and promote growth.[2 4] Appropriate oxygen treatment in this population may also be a factor in reducing the incidence of the sudden infant death syndrome.[5]

With improvements in neonatal care we are seeing increasing numbers of infants with chronic lung disease on our neonatal units and paediatric wards. A telephone survey, conducted by our unit of six level 3 neonatal intensive care units in the United Kingdom showed that none had a specific protocol for the administration or monitoring of oxygen treatment. This aspect of infant care needs further evaluation. The audit by Dodd et al should prompt us to develop guidelines to ensure adequate assessment, monitoring, and prescribing of oxygen requirements in this specific group of infants.

A Reece specialist registrar in paediatrics

L Alsford consultant paediatrician

A Shah consultant paediatrician Arvind@n-m-h.fsnet.co.uk North Middlesex Hospital, London N18 1QX

[1] Dodd ME, Kellet F, Davis A, Simpson JCG, Webb AK, Haworth CS, et al. Audit of oxygen prescribing before and after the introduction of a prescription chart. BMJ 2000;321:864-5. (7 October.)

[2] Poets CE When do infants need additional inspired oxygen? A review of the current literature. Pediatr Pulmonol 1998;26:424-8.

[3] Lucey JF, Dangman B. A reexamination of the role of oxygen in retrolental fibroplasia. Pediatrics 1984;73:82-96.

[4] Groothuis JR, Rosenberg AA. Home oxygen promotes weight gain in infants with bronchopulmonary dysplasia. AJDC 1987;141:992-5.

[5] Gray PH, Rogers Y. Are infants with bronchopulmonary dysplasia at risk for sudden infant death syndrome? Pediatrics 1994;93:774-7.

Advice to authors

We prefer to receive all responses electronically, sent either directly to our website or to the editorial office as email or on a disk. Processing your letter will be delayed unless it arrives in an electronic form.

We are now posting all direct submissions to our website within 24 hours of receipt and our intention is to post all other electronic submissions there as well. All responses will be eligible for publication in the paper journal.

Responses should be under 400 words and relate to articles published in the preceding month. They should include [is less than or equal to] 5 references, in the Vancouver style, including one to the BMJ article to which they relate. We welcome illustrations.

Please supply each authors current appointment and full address, and a phone or fax number or email address for the corresponding author. We ask authors to declare any competing interest. Please send a stamped addressed envelope if you would like to know whether your letter has been accepted or rejected.

Letters will be edited and may be shortened.

bmj.com letters@bmj.com

COPYRIGHT 2001 British Medical Association
COPYRIGHT 2001 Gale Group