Chronic lung disease (CLD)

Published on 03/06/2015 by admin

Filed under Neonatal - Perinatal Medicine

Last modified 22/04/2025

Print this page

This article have been viewed 1462 times

CHAPTER 13 Chronic lung disease (CLD)

Mark Davies, Garry Inglis

Background

There is no uniform definition of chronic lung disease (CLD), or bronchopulmonary dysplasia (BPD). Definitions are usually based on the need for respiratory support (whether oxygen or mechanical support) at a specified time point (28 days of age and/or 36 weeks post-menstrual age is frequently used). The Australian and New Zealand Neonatal Network (ANZNN) defines it as ‘any form of respiratory support (supplemental oxygen and/or assisted ventilation) for the initial chronic respiratory disease at 36 weeks postmenstrual age, in babies born at less than 32 weeks gestation’.

• Babies born at 23 weeks gestation have greater than 80% chance of getting CLD, decreasing to less than 10% in babies born at 31 weeks gestation.

• Babies with CLD have significant morbidity and it is a leading cause of late mortality.

Before discharge, babies with CLD require a longer duration of respiratory support (mechanical ventilation and continuous positive airway pressure) and oxygen treatment, and spend longer in hospital.

After discharge, many will need home oxygen and the rate of re-hospitalisation is high. Lung function measurements (especially measurements of air flow) are often below average, recurrent respiratory infections are common, and there is an increased risk of neurodevelopmental delay.

Management

The clinical course in babies with CLD will improve with time and growth — if they survive the respiratory failure that CLD brings. Numerous treatments have been tried to ameliorate established CLD. The mainstay of treatment remains postnatal systemic corticosteroids (see Dexamethasone below), but this has become increasingly controversial in recent years.

Other treatments that have been tried include inhaled steroids, bronchodilators, diuretics, fluid restriction, vitamin A, inhaled nitric oxide, sildenafil and erythromycin.

• Oxygen is given to target oxygen saturations >90% and <95%. Targeting higher saturations has been proven to be of no benefit and can become an endless cycle of increasing oxygen delivery.

• Some are aggressive in treating a patent ductus arteriosus in babies with CLD.

• Nutritional management is important — most of these babies need higher caloric intake than babies at similar ages without CLD.

• Some would consider respiratory syncytial virus (RSV) immunoprophylaxis.

Dexamethasone

For chronic lung disease (CLD)

Dexamethasone may be used for management of CLD, especially as an aid to weaning from assisted ventilation. Its use is controversial given an increased incidence of cerebral palsy (or an abnormal neurological examination), seen when multiple randomised controlled trials are combined in meta-analysis. However, it should be noted that the majority of trials allowed the use of dexamethasone in the nontreatment groups and the same meta-analysis showed no increase in the rate of disability.

• Dexamethasone is usually commenced at 7–14 days of age if ventilatory requirements are still significant, but is often started later than this.

• We suggest writing up the entire duration of the dexamethasone course at the beginning. This ensures that doses of dexamethasone are not overlooked during the course.

Be wary of infection when starting dexamethasone. In some smaller babies antibiotics may be used to ‘cover’ known colonising organisms over the first 4–5 days of a course.

Regimens

Numerous regimens for a weaning course of dexamethasone in CLD exist. Dexamethasone can be given intravenously (IV) or enterally.

Dexamethasone, 6-week course

• 0.5 mg/kg/day (given in two divided doses) for 3 days.

• Then 0.3 mg/kg/day (given in two divided doses) for 3 days.

• Then reduce dose by 10% each 3 days, until 0.1 mg/kg/day.

• Then 0.1 mg/kg/day (given in two divided doses) every other day for 6 days, and then cease.

[Avery GB et al. Controlled trial of dexamethasone in respirator-dependent infants with bronchopulmonary dysplasia. Pediatrics 1985;75:106–111.]

Dexamethasone, ‘2-week’ course

• 0.5 mg/kg/day (given in two divided doses) for 3 days.

• Then 0.3 mg/kg/day (given in two divided doses) for 3 days.

• Then 0.2 mg/kg/day (given in two divided doses) for 3 days.

• Then 0.1 mg/kg daily for 3 days, and then cease.

Dexamethasone, DART protocol

• 0.15 mg/kg/day (given in two divided doses) for 3 days.

• 0.1 mg/kg/day (given in two divided doses) for 3 days.

• 0.05 mg/kg/day (given in two divided doses) for 2 days.

• 0.02 mg/kg/day (given in two divided doses) for 2 days.

[Doyle LW et al. Low-dose dexamethasone facilitates extubation among chronically ventilator-dependent infants: a multicenter, international, randomized, controlled trial. Pediatrics 2006;117:75–83.]

For airway oedema

Dexamethasone is sometimes given to prevent failure of extubation where there is suspected oedema of the vocal cords or sub-glottis. The course is:

• 0.25 mg/kg/dose every 8 hours for 3 doses, the last dose given 1 hour before extubation.

Related

Pocket Notes on Neonatology 2e