Page 56 - Škrgat, Sabina, ed. 2023. Severe Asthma Forum - Monitoring and Treatable Traits in Severe Asthma. Koper: University of Primorska Press. Severe Asthma Forum, 2
P. 56
to corticosteroid treatment, but the phenoty- subject with severe asthma who is going to do
ping of the inflammatory response in asthma the induced sputum should be premedicated
severe asthma forum 2: severe asthma - monitoring and treatable traits in severe asthma has gained even greater clinical significance with 200 µg salbutamol. Sputum induction
with the introduction of biological therapy. A is performed by inhalation of increasing con-
great advantage of the technique is that it ena- centrations of aerosolized saline (0.9%, 3%,
bles sampling of the airways in a less-invasive 4% and 5%) through a mouthpiece without a
manner, in contrast with other methods such nose clip. In our clinic we use an Omrone NE
as bronchial biopsy, bronchial brushing and U07 ultrasonic nebulizer (Omron Healthcare
bronchoalveolar lavage, all of which require Europe) with an output of 1.0 mL/min and
bronchoscopy. This is particularly important particle size of 3.5 µm mass median diame-
in the examination of patients with severe ai- ter to generate an aerosol. Each concentration
rways disease where endoscopy poses signifi- should be inhaled over 7 minutes. After each
cant risk to oxygen desaturation5. These tech- inhalation, the patient should be asked to ex-
niques allow sputum to be obtained from 80 pectorate into a container for an analysis and
to 90% of patients, which is significantly more FEV1 or PEF is needed to be measured again.
than patients can expectorate spontaneously. The procedure should be interrupted if dys-
It has been shown that cells in induced spu- pnea or wheezing occurred and immediately
tum reflect well the findings in bronchial wash appropriate treatment should be provided.
and lavage samples and are more viable than If there is a fall in FEV1 or PEF on measure-
in spontaneous sputum6. Fahy et al. studied ment between different concentrations inha-
markers of inflammation and cells in sam- lation of 10-20% versus baseline, the same
ples obtained by sputum induction, bronc- concentration of saline should be used in the
hial washing and lavage samples from heal- next inhalation interval. If the fall is greater
thy and asthmatic subjects. Concentrations of than 20%, the procedure should be terminat-
cells and inflammatory markers were higher ed.30 Patients should be instructed to interrupt
in induced sputum samples than in bronchial the inhalation if they need to expectorate (in
washings or lavage materials. Induced spu- this case the clock was stopped and inhalation
tum samples contained higher percentages of continued after expectoration) or experience
neutrophils and eosinophils, and higher con- dyspnea or wheezing. The volume of the in-
centrations of eosinophil cationic protein, al- duced sputum should be recorded. Sputum
bumin and mucin-like glycoprotein, probably sample should be immediately trasferred into
because they were less diluted7. Induced spu- cytological laboratory.
tum was first developed as a research tool, and
in the meanwhile, it became a valuable clini- Processing of induced sputum
cal tool8. for cytological analysis and differential
cell counting
Sputum induction procedure
It is recommended to process induced spu-
Induced sputum is quite a technically de- tum a soon as possible or within 2 hours to
manding procedure. Each sputum induction ensure optimal cell preservation. Two differ-
should proceed by spirometry, and patients ent approaches can be followed for process-
with FEV1 <40% of predicted, or less than 1 ing, entire sputum analysis or more often se-
L, have to be excluded from induction pro- lected sputum plugs method. Selected sputum
cedure.35 The highest FEV1 value as well as plugs or „fishing“ method means selection of
PEF value obtained were considered as base- dense viscid portions of samples for analysis
line and were used to calculate a relative fall with minimising of saliva contamination9,10.
in FEV1 and PEF during the procedure. Each
ping of the inflammatory response in asthma the induced sputum should be premedicated
severe asthma forum 2: severe asthma - monitoring and treatable traits in severe asthma has gained even greater clinical significance with 200 µg salbutamol. Sputum induction
with the introduction of biological therapy. A is performed by inhalation of increasing con-
great advantage of the technique is that it ena- centrations of aerosolized saline (0.9%, 3%,
bles sampling of the airways in a less-invasive 4% and 5%) through a mouthpiece without a
manner, in contrast with other methods such nose clip. In our clinic we use an Omrone NE
as bronchial biopsy, bronchial brushing and U07 ultrasonic nebulizer (Omron Healthcare
bronchoalveolar lavage, all of which require Europe) with an output of 1.0 mL/min and
bronchoscopy. This is particularly important particle size of 3.5 µm mass median diame-
in the examination of patients with severe ai- ter to generate an aerosol. Each concentration
rways disease where endoscopy poses signifi- should be inhaled over 7 minutes. After each
cant risk to oxygen desaturation5. These tech- inhalation, the patient should be asked to ex-
niques allow sputum to be obtained from 80 pectorate into a container for an analysis and
to 90% of patients, which is significantly more FEV1 or PEF is needed to be measured again.
than patients can expectorate spontaneously. The procedure should be interrupted if dys-
It has been shown that cells in induced spu- pnea or wheezing occurred and immediately
tum reflect well the findings in bronchial wash appropriate treatment should be provided.
and lavage samples and are more viable than If there is a fall in FEV1 or PEF on measure-
in spontaneous sputum6. Fahy et al. studied ment between different concentrations inha-
markers of inflammation and cells in sam- lation of 10-20% versus baseline, the same
ples obtained by sputum induction, bronc- concentration of saline should be used in the
hial washing and lavage samples from heal- next inhalation interval. If the fall is greater
thy and asthmatic subjects. Concentrations of than 20%, the procedure should be terminat-
cells and inflammatory markers were higher ed.30 Patients should be instructed to interrupt
in induced sputum samples than in bronchial the inhalation if they need to expectorate (in
washings or lavage materials. Induced spu- this case the clock was stopped and inhalation
tum samples contained higher percentages of continued after expectoration) or experience
neutrophils and eosinophils, and higher con- dyspnea or wheezing. The volume of the in-
centrations of eosinophil cationic protein, al- duced sputum should be recorded. Sputum
bumin and mucin-like glycoprotein, probably sample should be immediately trasferred into
because they were less diluted7. Induced spu- cytological laboratory.
tum was first developed as a research tool, and
in the meanwhile, it became a valuable clini- Processing of induced sputum
cal tool8. for cytological analysis and differential
cell counting
Sputum induction procedure
It is recommended to process induced spu-
Induced sputum is quite a technically de- tum a soon as possible or within 2 hours to
manding procedure. Each sputum induction ensure optimal cell preservation. Two differ-
should proceed by spirometry, and patients ent approaches can be followed for process-
with FEV1 <40% of predicted, or less than 1 ing, entire sputum analysis or more often se-
L, have to be excluded from induction pro- lected sputum plugs method. Selected sputum
cedure.35 The highest FEV1 value as well as plugs or „fishing“ method means selection of
PEF value obtained were considered as base- dense viscid portions of samples for analysis
line and were used to calculate a relative fall with minimising of saliva contamination9,10.
in FEV1 and PEF during the procedure. Each
