Pulmonary function test PFT Spirometry pediatric Children indication ATS ERS Reference equation

1. Spirometry In
Children
Waheed Shouman
Chest Professor, Zagazig University

2.  The examination of lung function in
children is not easy .
 There is no gold standard method to
monitor pulmonary function in children
below 6 years
 The assessment of lung function in infants
and younger children is more challenging
and it is usually not included in routine
clinical examinations as it may require
sedation

3. •According to ATS and the ERS it would not be ethically
acceptable to sedate preschool children for pulmonary
function testing

4. Indications of PFT in children:
(1) Detection and identification of lung
disease (diagnosis)
(2) Assessment of disease progress
(disease monitoring and staging) and
(3) Analysis of therapy effectiveness
(therapy monitoring and optimization)

5. No child will cooperate with any
test if they feel threatened
intimidated

6. PFT that can be done in Children:
•Spirometry
•Plethysmograthy (Box)
•Impulse Oscillometry (IOS)
•Interruption Technique
•Gas Washout test (single or multiple breath)
•Hypoxia Challege Test
•Respiratory Inductive Plethysmography
•Electric Inductive Tomography
•Forced Deflation Technique (neonates and below 2 years)
•Fe No
•Eosophageal and Gastric Manometry
•Others,

8. Spirometry

9. Spirometry:
•“the measuring of breath”
•Spirometry is the basic examination in
lung function testing
•Spirometry is an established method to
study lung function in children

11. Reasons to perform spirometry in a
pediatric patient:
•To establish whether pulmonary mechanics are normal in a child with
symptoms.
•To define the nature and severity of any pulmonary dysfunction
(obstructive vs restrictive defect).
•To define the site of airway obstruction—central vs peripheral or
intrathoracic vs extrathoracic.
•To follow the course of pulmonary disease or assess the effect of
therapy.
•To establish the presence or absence of airway reactivity.
•To assess the risks of diagnostic or therapeutic procedures.
•To monitor for adverse effects of chemotherapy or radiation therapy.
•To predict prognosis or assess disability and to assess the effect of
disease on lung growth.

13. • Spirometry is a good measure of
obstructive lung disese in children
• It underestimate peripheral airway disese
• It can help to assess BHR, BDR

14. Contraindications for spirometry:
•No ABSOLUTE contraindications
•Some conditions may have a relative danger to a
patient or affect the validity of spirometry
performance and results.

15. Relative contraindications for
Spirometry:
•Hemoptysis of unknown origin
•Recent pneumothorax
•Thoracic, abdominal, or cerebral aneurysms
•Recent thoracic, abdominal or eye surgery
•Acute disorders such as nausea or vomiting
•Severe respiratory distress
•Physical limitations
•Cognitive impairment, dementia
•Inability to adequately understand and follow instructions
(except when familiarising child with spirometry)

16.  Spirometry in pre-school children has repeatedly
shown high failure rates, especially when
performing maximum expiratory flow volume
(MEFV) manoeuvres
 It was attributed to lack of coordination and poor
attention

17. • 95% of 8- to 9-year-old children were able to yield
adequate data
• From the age of six, children are usually able to
undergo the same examinations as adults
• Typically a child around 5 years old will have a
50% chance of performing spirometry adequately
in a child orientated lab
• Some children aged 3–5 are able to achieve
reproducible efforts if the standard (adult)
guidelines are modified

18. Individuals interested in obtaining
spirometric results in young subjects
must be prepared to devote financial
resources to equipment and well-trained
technicians who are given adequate time
to work with the children

19. ATS/ERS recommend:
1.Development of reference equations that can cross from
preschool- into school-age children
2.Investigation of the utility of shorter timed expiratory
volumes (e.g., FEV0.5)
3. Development of software that automatically identifies
maneuvers that may not meet these quality-control
criteria,and which better assesses end of test in very young
children

20. ATS/ERS recommend:
4. Assessing both short- and long-term variability of these
spirometric maneuvers in the preschool-aged child
5. Defining bronchodilator response in the individual child
6. Assessing the clinical applicability of this technique in
various disease states

21. ATS/ERS recommend:
1.Reference values from adults should not be extrapolated for children
less than 6 years old Testing children in “adult” laboratories requires
extra time and effort
2.The validity of the selected reference data for use in those with
respiratory disease should be checked by studying at least 30 to 50
healthy preschool children using identical techniques and comparing
their results with those of the similar reference population (same age,
body size, sex, and ethnic group)
3. Results should, by preference, be expressed as z scores (i.e., multiples
of the standard deviation [SD] from the mean) and not as percentages of
predicted values
4.Variability measurements should not be extrapolated from healthy
children to those with disease. Within-subject variability (within and
between occasions) assessments need to be made in at least 30
(preferably more) subjects of similar age and diagnostic category

25. Performing Spirometry

26. The quality of the findings obtained by pulmonary
function testing in infants and children is very much
dependent on the person performing the test
Only fully dedicated investigators guarantee good
quality and reproducible results
The children need to be trained and motivated
Experienced and patient personnel are required to
fulfil this task.

27. Factors affecting spirometry
in children:
•Height
•Age
•Sex
•Environmental factors
•Weight
•Ethnicity
•Prematurity
•Patient cooperation
•Effort and technical factors

28. • Height is the most important predictive
variable for lung function, followed by race
• Height measurement should be performed
at the time of spirometry.
• For nonambulatory patients, arm span can
be used to estimate height

30. If a child refused to
perform the spirometry:
•Ask parenets to do it in front of him
•If refused or can't, Praise and reward and re-
book
•Next time: Most children will be happy to
participate as they know that they will be
rewarded

31. • The nose is often covered with a
nose clip, they will breathy orally
in simple way than adults.
• The child must not wear clothing
that restricts chest movements.
• Feet must be on ground, whether
they are sitting or standing.

32. • Appropriate repeatability is defined as at
least two acceptable curves, with the
second highest FVC and FEV1 within 0.1 L
or 10% of the highest value, whichever is
greater
• Loops need to be rejected if they are less
than 0.5 s in duration, as no FEVt can be
reported

33. • Young children have small absolute lung volumes
and large airway size relative to lung volume
compared with older children and adults.
• American Thoracic Society criteria for acceptable
spirometry call for a 3-second exhalation in
children (6 seconds for adults and older children)
• Forced expiration is completed in a shorter time,
certainly more quickly than the 6 seconds
recommended for adults, but sometimes more
quickly than 1 second

34. • Minimum of three manoeuvres should be
recorded as in adults, but pre-school children
may undertake 10 or more attempts without
exhaustion until they achieve perfect technique
and an acceptable spirometric recording
• FEV0.75 and FEV0.5 have been used. In children
aged 6 years or younger, FEV0.75 was found to
provide information similar to that of FEV1

37. • The best loop is that with the highest sum
of FVC and FEV0.5 [as FEV0.5 is the
commonest FEVt to be recorded in children
less than 6 years.
• The flows MEF25, MEF50, MEF75 and MMEF,
are taken from the best loop.
• The highest values for FEV0.5, FEV0.75,
FEV1 and FVC are taken from any of the
technically acceptable loops

38. PEF
•PEF is a simple but very rough control measure
used in follow-up of respiratory diseases, above all
in asthma
•There is good evidence that routine home
monitoring of peak flow in each asthmatic child is
not justified and not useful

39. • PEF measured by a peak flow meter rather than by
a spirometer is inaccurate and overestimated in
the range of 200–400L/min
• When available, spirometers should be preferred
to peak flow meters for measuring lung function in
children.
• Studying FEV1, FEV1/FVC, and FEF25-75 in
children with asthma, it was found that FEF25-75
is a more sensitive indicator of airway obstruction.

40. FEV1:
•It can not be obtained in very young children
•No evidence that it help in asthma control
•Values above 80% of predicted are
considered normal

41. FEV1/FVC:
•Though the FEV1/FVC ratio is considered a
valuable indicator when assessing obstructive
airway disease, pre-school children have reported
ratios of FEV1/FVC as high as 90 to 95%
•The higher elastic recoil and more rapid emptying
of the lungs in the pediatric population can also lead
to a higher FEV1/FVC ratio
• FEV1/FVC ratio >80% is considered normal results

42. FVC and RV:
There is insufficient evidence to recommend
monitoring in clinical practice

43. Reversibility:
•ATS/ERS standards for interpretation suggest a minimal
change for significance is a 12% increase in FEV1 or FVC,
with a minimal absolute change of 200 mL. There is no
reference to children; 200 mL represents a much larger
relative volume in a small child than in an adult
•There are no national or international guidelines specific to
children for the interpretation of BDR, 10% was suggested in
one longitudinal study and FEF25% –75% by 20% to 30%

44. Longitudinal studies for same
child:
A minimum change from baseline for significance
has been defined by some as ±10% for FVC and
FEV1, and ±25% for FEF 25%-75%

45. Thank You