Title           : Reference value of Forced Oscillation Technique for healthy preschool children

Researcher       : Clin.Prof.Suwat Benjaponpitak 

Department     : Faculty of Medicine, Siam University, Bangkok, Thailand

E-mail                : med@siam.edu

Abstract            :  Background: The reference values of Forced Oscillation Technique (FOT) parameters of the inspiratory and expiratory phase for preschool children have not yet been established.

Objective: To evaluate FOT measures in Thai healthy preschool children.

Methods: Preschool children, aged 3-6 years, were screened. Children who were positive for the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire for asthma, positive family history of allergic diseases, recent lower respiratory tract infections, and environmental tobacco smoke were excluded. FOT parameters, including resistance (Rrs), reactance (Xrs), frequency of resonance (Fres) and area of reactance (ALX), were measured.

Results: A total of 390 healthy children with the mean age of 5.1 ± 0.9 years were enrolled. FOT was successfully performed in 378 children (96.9%). The mean (SD) for the whole breath (WB) resistance at 5Hz (R5), 20 Hz (R20) and R5-20 were 11.49 (2.69) cmH2O/L/s, 9.46 (2.19) cmH2O/L/s and 2.02 (0.82) cmH2O/L/s, respectively. The median (IQR) for WB reactance at 5Hx (X5), Fres and ALX were -1.51 (-2.37 to -0.96) cmH2O/L/s, 11.17 (8.50-15.65) Hz, and 7.53 (3.72-14.32) cmH2O/L/s, respectively. Significantly difference in WB R5, R20, X5, Fres and ALX between male and female children were demonstrated. The expiratory phase R5, R20, R5-20 were significantly higher than those of the inspiratory phase (p < 0.001). There are significant correlations between the height and FOT parameters. Reference curve for the FOT parameters was generated based on height using the lambda-mu-sigma (LMS) method.

Conclusion: Reference curve of FOT parameters measured in healthy preschool children were demonstrated. Majority of preschool children could perform FOT method.

Key words: Respiratory resistance, Respiratory reactance, LMS method, Frequency of resonance, Area of reactance

Link to article : Asian Pacific Journal of Allergy and Immunology, 2021, 39(2), pp. 89–95. DOI: 10.12932/AP-110618-0334

Journal : Asian Pacific journal of allergy and immunology / in Scopus

Bibliography     : Mukdjindapa, P., Manuyakorn, W., Kiewngam, P., Sasisakulporn, C., Pongchaikul, P., Kamchaisatian, W., & Benjaponpitak, S. (2021). Reference value of Forced Oscillation Technique for healthy preschool children. Asian Pac J Allergy Immunol, 39(2), 89–95. doi: 10.12932/AP-110618-0334. Epub ahead of print. PMID: 30525741.

Title           :  Safety and efficacy of ant rush immunotherapy in children

Researcher       : Clin.Prof.Suwat Benjaponpitak 

Department     : Faculty of Medicine, Siam University, Bangkok, Thailand

E-mail                : med@siam.edu

Abstract            :  Background: The Rush Immunotherapy (RIT) protocol is a valid alternative in order to reach the maintenance phase early. However, there are scarce studies in the literature that have evaluated the safety and the efficacy of an ant RIT process in children.

Objective: To evaluate the safety and the efficacy of an ant RIT protocol and to identify the risk factors for systemic reactions (SRs) during an RIT procedure in children.

Method: A retrospective review was conducted for those children who were receiving an ant RIT procedure. The 3-day RIT protocol consisted of hourly subcutaneous injections in order to achieve a 0.5 ml maintenance dose of a 1:100 weight/ volume (wt/vol) of the Solenopsis invicta whole body extract. The safety for an RIT procedure was monitored by using the World Allergy Organization Subcutaneous Immunology Systemic Reaction Grading System. The efficacy was assessed by the reactions after a field ant re-sting.

Result: A total of 20 children who were receiving an ant RIT therapy were reviewed. The mean age was 9.5±3.07 years. There were 6 systemic reactions (SRs) from 324 injections during the RIT procedure (1.85%). All of the systemic reactions were Grade 1-2. There were no associations of SRs regarding age, gender, an atopic history, or the levels of immunoglobulin E (IgE) sensitization to the ants. Among the 14 patients who experienced a field ant re-sting, 4 (28.5%) patients developed Grade 3 SRs. These Grade 3 reactions were resolved after an increase of the maintenance dose to 0.5 ml of a 1:50 wt/vol. There was a significant difference in the mean age of those children who had ant re-sting systemic reactions and those who had no reactions (6.75±0.95 year vs. 10.8±3.29, p=0.036).

Conclusion: Rush immunotherapy with ant in children is safe and it has a low occurrence of severe systemic reactions. It is an alternative treatment for those patients requiring a rapid protection.

Link to Academic article: DOI: 10.12932/AP0831

Journal : Asian Pacific journal of allergy and immunology  Vol. 35 No. 3 September 2017

Bibliography     : Manuyakorn, W., Benjaponpitak, S., Kamchaisatian, W., Sasisakulporn, C., & Jotikasthira, W. (2017, September). Safety and efficacy of ant rush immunotherapy in children. Asian Pac J Allergy Immunol, 35(3), 156-160. doi: 10.12932/AP0831. PMID: 27996286.