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Year : 2017  |  Volume : 31  |  Issue : 2  |  Page : 83-86

Pediatric peak expiratory flow rate nomograms for Ernakulam district

Department of Paediatrics, Azeezia Medical College, Kollam, Kerala, India

Date of Web Publication29-Sep-2017

Correspondence Address:
Jomon Mathew John
House No. 44/2398 - Nirmal Enclave Santhipuram Road, Palarivattom, Ernakulam - 682 025, Kerala
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/ijaai.ijaai_6_17

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Objective: To obtain the normal reference values of peak expiratory flow rates (PEFRs) among healthy school-going children between 8 and 12 years and thereby construct a nomogram.
Materials And Methods: A cross-sectional study was conducted among healthy children attending schools in Ernakulam district over a period of 1 year. PEFR values were recorded using a Mini-Wright peak flow meter, and the best of three readings was documented.
Results: Nine hundred and fifty-four students were studied. PEFR increases as the age increases. A similar trend was observed across various heights. Nomograms based on age and height were constructed separately for boys and girls.
Conclusion: Established baseline values of PEFR in this study can be useful in diagnosing and following asthmatic children in Ernakulam district.

Keywords: Asthma, nomogram, regional reference values

How to cite this article:
John JM. Pediatric peak expiratory flow rate nomograms for Ernakulam district. Indian J Allergy Asthma Immunol 2017;31:83-6

How to cite this URL:
John JM. Pediatric peak expiratory flow rate nomograms for Ernakulam district. Indian J Allergy Asthma Immunol [serial online] 2017 [cited 2023 Mar 26];31:83-6. Available from: https://www.ijaai.in/text.asp?2017/31/2/83/215842

  Introduction Top

Peak expiratory flow rate (PEFR) is the maximum flow rate generated during a forceful exhalation, starting from full lung inflation. Peak flow rate essentially reflects large airway flow and depends on the voluntary effort and muscular strength of an individual. PEFR as a measurement of ventilatory function was introduced by Hadron in 1942 and was accepted in 1949 as an index in spirometry.[1] Use of Mini-Wright peak flow meter, a portable, hand-held device, provides an objective measure of lung function that can indicate airway hyperresponsiveness, warn of impending asthma exacerbation and can assess the severity of disease activity.[2] Action plans based on symptoms and PEFR readings to guide treatment of acute asthma can be lifesaving.

Owing to their smaller stature, breathing zone of children is lower, so they inhale air loaded with more particles. Diameters of their airways are smaller and therefore more likely to be affected by inflammation produced by air pollution. Their lungs are still developing and hence are more vulnerable to air-borne insults. The efficiency of detoxification system of the body develops in a time-dependent pattern. This in part accounts for increased susceptibility of children at critical points of time. Moreover, finally, their immune defense is immature and hence less active against inhaled pathogens.[3]

When children and adults particle doses are compared, the absolute dose could represent a misleading parameter as it does not take into account the different air–tissue interfaces (alveolar surface area exposed to air) in the alveolar region of the lung. Children's alveolar surface area keeps growing (2.8 m 2 at birth) and reaches a maximum value at the age of 20 years (about 75 m 2).[4],[5] Therefore, children exposed to lower absolute particle concentrations can anyhow lead to a higher deposited particle “density” (i.e., dose normalized to the actual available air–tissue interface) in the alveolar region.

Peak flow rate is most frequently used in home monitoring of asthma, where it can be beneficial in patients for both short- and long-term monitoring. When properly performed and interpreted, peak flow rate measurement can provide a patient and clinician with objective data on which therapeutic decisions can be made. Most studies have shown that when PEFR monitoring is linked to a comprehensive program, combined with symptom diaries and patient education, it was associated with an improvement in outcomes, such as decreased hospital visits and improved quality of life.[6],[7],[8],[9] Thus, nomograms must be made available for primary caregivers of asthmatic children.

Unfortunately, specific nomograms showing PEFR values for normal children are not available in all parts of India, especially in a rapidly urbanizing town like Ernakulam, wherein air pollution could soon be a major concern. A study was therefore planned to measure PEFR in healthy school-going children between 8 and 12 years of age living in Ernakulam district, Kerala, to determine reference values for the regional population and construct a nomogram.

  Materials and Methods Top

A cross-sectional study was conducted in Ernakulam district among healthy school-going children between 8 and 12 years over a period of 12 months starting from April 2014. After the approval of the institutional ethical committee, each school which gave their consent was visited one at a time to distribute consent forms and pro forma. On the second visit, all children who satisfied the study criteria and had obtained consent were studied. Children with a history of wheeze, nocturnal cough, allergy, tuberculosis contact, and acute respiratory tract illness in the preceding 7 days and family history of asthma, tuberculosis, and allergy were excluded from the analysis. Each child was clinically examined for the presence of cough, fever, chest retractions, chest deformities, wheezing, rales, or any major illness affecting the cardiovascular, respiratory, gastrointestinal, and central nervous systems. The procedure of PEFR measurement was first demonstrated and two trials were given. Three readings were noted, and the best of three was taken as PEFR of the child. Disposable mouth piece was used for recording PEFR.

  Results Top

The distribution of gender and age was studied [Table 1]. Bar charts are also drawn to visually understand the distribution [Figure 1]. Nine hundred and fifty-four children were included in this study. From the distribution of sex, it can be concluded that there is not much difference in number of girls and boys [Figure 2].
Figure 1: Bar chart showing frequency distribution

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Figure 2: Bar chart for gender distribution

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Table 1: Distribution of age and gender

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It can be observed that mean PEFR for 12 years of age is maximum for males and females, followed by 11, 10, 9, and 8 years of age. This suggests that in boys and girls, mean PEFR increases as the age increases. A similar trend was observed across various heights [Table 2] and [Table 3].
Table 2: Mean and standard deviation of peak expiratory flow rate for different ages

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Table 3: Mean and standard deviation of peak expiratory flow rate for different height groups

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Nomograms based on age and height were constructed separately for boys and girls [Figure 3], [Figure 4], [Figure 5], [Figure 6].
Figure 3: Nomogram based on age for girls

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Figure 4: Nomogram based on height for girls

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Figure 5: Nomogram based on age for boys

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Figure 6: Nomogram based on height for boys

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  Discussion Top

Measurement of PEFR has gained worldwide importance in clinical practice for the evaluation of patients with obstructive and restrictive airway diseases, particularly following the development of simple handy instrument such as the Mini-Wright peak flow meter. Moreover, assessment of lung functions both qualitatively and quantitatively in both healthy subjects and patients has become important in the field of respiratory medicine. An early detection of asthmatic exacerbations by means of objective measurement can provide a solution to these problems and stimulate the development of self-management and self-control techniques. The lack of perception of the degree of pulmonary obstruction is an important cause for delay in the initiation of treatment. Parents often fail to recognize the severity of the episode resulting in death of some children before arriving at the hospital, especially in children with difficult to control asthma. Early recognition of these asthmatic exacerbations can be made by measuring PEFR, and also it is useful in assessing the response to therapy.

Our aim was to establish normal PEFR values of healthy school-going children in Ernakulam district and thereby use it as a reference value to assess the airway obstruction for the regional population. With the help of the constructed nomograms, comparison between observed and expected PEFR is made easy, and the parents can use them to monitor the effectiveness of therapy.

  Conclusion Top

It is important to have reference standards for detecting abnormal values. Reference values are affected by regional and environmental factors. Therefore, it is necessary to have regional values for children. Established baseline values of PEFR in this study can be useful in diagnosing and following asthmatic children in Ernakulam district. Nomograms have been constructed for boys and girls separately, based on age and height.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

  References Top

Jain SK, Kumar R, Sharma DA. Peak expiratory flow rates in healthy Indian adults: A statistical evaluation. Lung India 1983;3:88-91.  Back to cited text no. 1
Kercsmar CM. Asthma. In: Chernick V, Boat TF, editors. Kendig's Disorders of the Respiratory Tract in Children. 6th ed. USA: W.B. Saunders Company; 1998. p. 888-730.  Back to cited text no. 2
Heinrich J, Slama R. Fine particles, a major threat to children. Int J Hyg Environ Health 2007;210:617-22.  Back to cited text no. 3
Dunnill MS. Postnatal growth of the lung. Thorax 1962;17:239-333.  Back to cited text no. 4
Thurlbeck WM. Postnatal human lung growth. Thorax 1982;37:564-71.  Back to cited text no. 5
Ignacio-Garcia JM, Gonzalez-Santos P. Asthma self-management education program by home monitoring of peak expiratory flow. Am J Respir Crit Care Med 1995;151:353-9.  Back to cited text no. 6
Lahdensuo A, Haahtela T, Herrala J, Kava T, Kiviranta K, Kuusisto P, et al. Randomised comparison of guided self management and traditional treatment of asthma over one year. BMJ 1996;312:748-52.  Back to cited text no. 7
Brouwer AF, Brand PL. Asthma education and monitoring: What has been shown to work. Paediatr Respir Rev 2008;9:193-9.  Back to cited text no. 8
Janson SL, McGrath KW, Covington JK, Baron RB, Lazarus SC. Objective airway monitoring improves asthma control in the cold and flu season: A cluster randomized trial. Chest 2010;138:1148-55.  Back to cited text no. 9


  [Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6]

  [Table 1], [Table 2], [Table 3]


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