More information about text formats
We read with interest the recent article by Stordal et al. on acid
suppression in children in with asthma and gastro-oesophageal reflux
disease. The authors concluded omeprazole treatment did not improve
asthma symptoms or lung function in children with asthma and gastro-oesophageal reflux disease.
Since Kennedy. first reported the association between gastro-oesophageal reflux and lung di...
Since Kennedy. first reported the association between gastro-oesophageal reflux and lung disease 43 years ago, a number of publications
have reported its’ strong association with asthma; prevalence ranging from
34% to 89%. If acid suppression is really achieved in the current
study, why was there a negative result? We believe there are important
potential limitations in the study.
There are concerns about the management of the study subjects. The
severity of asthma was classified as the GINA guidelines. According to
the authors, 31 children had persistent asthma (steps 2 and 3) and seven
had episodic asthma. Yet, 34 patients were administered daily-inhaled
steroids (indicated for steps 2 and beyond as per GINA guidelines).
Similarly, long acting bronchodilators are indicated for use in moderate
and severe persistent asthma (steps 3 and 4). However, these drugs were
used in 22 children while there were only 17 children with moderate
persistent asthma in the study. From this it appears that the study
subjects were over-treated.
To evaluate the effect of acid suppression on symptom control in
children with asthma and gastro-oesophageal reflux, it is desirable to
enrol children with asthma who have symptoms attributable to gastro-oesophageal reflux. The diagnosis of gastro-oesophageal reflux disease by
a 24-hour pH study and documentation of reflux index alone is not enough.
The quality of study may have been improved by simultaneously measurement
of proximal and distal oesophageal pH using dual probes, correlation of pH
changes with episodes of cough and asthma exacerbation, measurement of
peak expiratory flow rate and forced expiratory volume in the first second
during or immediately after a reflux episode.
Authors did not enrol children with ‘difficult to control’ asthma.
In clinical practice, the important question to address is ‘whether
therapy for gastro-oesophageal reflux improves asthma symptom control in
children with difficult asthma and reflux disease? Previous studies
showed reflux is reportedly more common in poorly controlled patients than
in well-controlled patients[6,7] suggesting that reflux may be
responsible for poor control.
The duration of acid suppression was too short to show a predictable
improvement in asthma. Longer period of suppression is essential for
proper assessment of clinical parameters (i.e. changes in asthma
medication, reduction in method dosage, number of exacerbations and
In addition, it is not clear whether any anti-reflux measures were
used in the study subjects such as prokinetics and lifestyle
modifications. These may be important as preventing reflux may in itself
lead to symptom control as has been seen with surgical treatment.
A major flaw in the study design, also mentioned by the authors, was
the small sample size. With such small sample size the possibility of type
II error cannot be excluded. The authors may provide more details of the
sample size calculation.
Clinicians should interpret this study with caution. The study does
not mean that acid suppression should not be used in children with asthma
and gastro-oesophageal reflux disease. In absence of robust evidence
against use of acid suppression, it could be tried in any child with
difficult to control asthma associated with gastro-oesophageal reflux
disease, along with other medical measures.
1. Stordal K, Johannesdottir GB, Bentsen BS, et al. Acid suppression does
not change respiratory symptoms in children with asthma and gastro-
oesophageal reflux disease. Arch Dis Child 2005; 90: 956-60.
2. Kennedy, JH. `Silent' gastro esophageal reflux: an important but little
known cause of pulmonary complications. Dis Chest.1962; 42: 42-45.
3. Harding SM, Richter JE.The role of gastro esophageal reflux in chronic
cough and asthma. Chest 1997; 111: 1389-1402.
4. Von Mutius E. Presentation of new GINA guidelines for paediatrics. The
Global Initiative on Asthma. Clin Exp Allergy 2000; 30 (suppl 1): 6–10.
5. Mathew J L, Singh M, and Mittal S K. Gastro-oesophageal reflux and
bronchial asthma: current status and future directions. Postgrad Med J
2004; 80: 701 - 705.
6. Chopra K , Matta SK, Madan N, et al. Association of gastro esophageal
reflux (GER) with bronchial asthma. Indian Pediatr 1995; 32: 1083–86.
7. Khoshoo V, Le T, Haydel RM Jr, Landry L, et al. Role of gastro
esophageal reflux in older children with persistent asthma. Chest 2003;
8. Kiljander TO, Salomaa ER, Hietanen EK, et al. Gastroesophageal reflux
and bronchial responsiveness: correlation and the effect of
fundoplication. Respiration 2002; 69: 434–9.