Sonographic evaluation of normal diaphragmatic thickness and excursion in Malaysia paediatric population: A single-institution cross-sectional study

INTRODUCTION: Diaphragmatic dysfunction is often underdiagnosed as clinical presentation is non-specific and reference values for normal diaphragmatic excursion are inadequate. The rationale of this study is to provide a normal reference value of diaphragmatic excursion and thickness in Malaysia's paediatric population using M-mode sonography, as no previous local data are available to our knowledge.

MATERIALS AND METHODS: A total of 119 healthy infants and children fulfilling our inclusion and exclusion criteria were recruited. They were divided into three groups according to age - 0-2 years old in group 1; 2-6 years old in group 2; 6- 12 years old in group 3. Sonography B-mode was used to assess bilateral diaphragmatic thickness and M-mode to assess diaphragmatic excursion during quiet spontaneous respiration.

RESULTS: In our paediatric population, the normal right and left diaphragmatic thickness were 2.0 mm ± 0.5 and 2.0 mm ± 0.5 for group 1; 2.5 mm ± 0.8 and 2.4 mm ± 0.6 for group 2; 2.7 mm ± 0.7 and 2.5 mm ± 0.5 for group 3, respectively. The normal right and left diaphragmatic excursion were 7.7 mm ± 2.5 and 7.3 mm ± 2.6 for group 1; 11.5 mm ± 3.8 and 10.6 mm ± 3.8 for group 2; 13.8 mm ± 3.9 and 12.9 mm ± 3.3 for group 3, respectively (data presented in mean ± standard deviation). There were no significant differences between two genders for each group. Significant positive correlation between age, weight, height, and body surface area with bilateral diaphragmatic thickness and excursion were detected in all studied population. The percentage difference between excursions of both hemidiaphragm was below 40%.

CONCLUSIONS: M-mode sonography is the modality of choice for diaphragmatic kinetics especially in paediatric population. This study provides normal sonographic reference value of diaphragmatic excursion and thickness in the Malaysian paediatric population as well as percentile curves for right diaphragmatic excursion plotted against body weight. The availability of this data will aid in the diagnosis of diaphragmatic dysfunction and hence immediate intervention for better recovery.