Dataset Information

Peak nasal inspiratory flow as outcome for provocation studies in allergen exposure chambers: a GA²LEN study.

ABSTRACT:

Background

The GA²LEN chamber has been developed as a novel mobile allergen exposure chamber (AEC) allowing standardized multicenter trials in allergy. Hitherto, subjective nasal symptom scores have been the most often used outcome parameter, but in standardized modern trials objective parameters are preferred. Despite its practicability, the objective parameter peak nasal inspiratory flow (PNIF) has been rarely used for allergy trials in the setting of allergen exposure chambers. This study aims to evaluate PNIF as an outcome parameter for provocation studies in AECs.

Methods

In a randomized controlled blinded setting subjects suffering from allergic rhinitis were exposed to grass pollen, birch pollen, house dust mite and/or placebo in the GA²LEN chamber. Different allergen concentrations were used to evaluate symptom severities. Patients had to perform PNIF before and every 30 min during a challenge using a portable PNIF meter.

Results

86 subjects participated in 203 challenges, altogether. House dust mite provocations caused the greatest reduction in PNIF values, followed by grass pollen and birch pollen. Provocations with every allergen or pollen concentration led to a significant decrease (p < 0.05) in PNIF compared to baseline. Furthermore, positive correlations were obtained between PNIF and peak expiratory flow, height and weight, and inverse correlations between PNIF and total nasal symptom score, nasal congestion score and visual analog scale of overall subjective symptoms.

Conclusion

PNIF is a helpful and feasible tool for conducting provocation trials with allergens, especially grass pollen and house dust mite, in an AEC.

SUBMITTER: Boelke G

PROVIDER: S-EPMC5604509 | biostudies-literature | 2017

REPOSITORIES: biostudies-literature

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Publications

Peak nasal inspiratory flow as outcome for provocation studies in allergen exposure chambers: a GA<sup>2</sup>LEN study.

Boelke Georg G Berger Uwe U Bergmann Karl-Christian KC Bindslev-Jensen Carsten C Bousquet Jean J Gildemeister Julia J Jutel Marek M Pfaar Oliver O Sehlinger Torsten T Zuberbier Torsten T

Clinical and translational allergy 20170917

<h4>Background</h4>The GA<sup>2</sup>LEN chamber has been developed as a novel mobile allergen exposure chamber (AEC) allowing standardized multicenter trials in allergy. Hitherto, subjective nasal symptom scores have been the most often used outcome parameter, but in standardized modern trials objective parameters are preferred. Despite its practicability, the objective parameter peak nasal inspiratory flow (PNIF) has been rarely used for allergy trials in the setting of allergen exposure chamb ...[more]

PMID: 28932387

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Project description:BackgroundOptimal flow settings during high-flow nasal cannula (HFNC) therapy are unknown. We investigated the optimal flow settings during HFNC therapy based on breathing pattern and tidal inspiratory flows in patients with acute hypoxemic respiratory failure (AHRF).MethodsWe conducted a prospective clinical study in adult hypoxemic patients treated by HFNC with a fraction of inspired oxygen (FIO2) ≥ 0.4. Patient's peak tidal inspiratory flow (PTIF) was measured and HFNC flows were set to match individual PTIF and then increased by 10 L/min every 5-10 min up to 60 L/min. FIO2 was titrated to maintain pulse oximetry (SpO2) of 90-97%. SpO2/FIO2, respiratory rate (RR), ROX index [(SpO2/FIO2)/RR], and patient comfort were recorded after 5-10 min on each setting. We also conducted an in vitro study to explore the relationship between the HFNC flows and the tracheal FIO2, peak inspiratory and expiratory pressures.ResultsForty-nine patients aged 58.0 (SD 14.1) years were enrolled. At enrollment, HFNC flow was set at 45 (38, 50) L/min, with an FIO2 at 0.62 (0.16) to obtain an SpO2/FIO2 of 160 (40). Mean PTIF was 34 (9) L/min. An increase in HFNC flows up to two times of the individual patient's PTIF, incrementally improved oxygenation but the ROX index plateaued with HFNC flows of 1.34-1.67 times the individual PTIF. In the in vitro study, when the HFNC flow was set higher than PTIF, tracheal peak inspiratory and expiratory pressures increased as HFNC flow increased but the FIO2 did not change.ConclusionMean PTIF values in most patients with AHRF were between 30 and 40 L/min. We observed improvement in oxygenation with HFNC flows set above patient PTIF. Thus, a pragmatic approach to set optimal flows in patients with AHRF would be to initiate HFNC flow at 40 L/min and titrate the flow based on improvement in ROX index and patient tolerance.Trial registrationClinicalTrials.gov (NCT03738345). Registered on November 13th, 2018. https://clinicaltrials.gov/ct2/show/NCT03738345?term=NCT03738345&draw=2&rank=1.

Dataset Information

Peak nasal inspiratory flow as outcome for provocation studies in allergen exposure chambers: a GA²LEN study.

Background

Methods

Results

Conclusion

Publications

Peak nasal inspiratory flow as outcome for provocation studies in allergen exposure chambers: a GA<sup>2</sup>LEN study.

Similar Datasets

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Tweets

Dataset Information

Peak nasal inspiratory flow as outcome for provocation studies in allergen exposure chambers: a GA2LEN study.

Background

Methods

Results

Conclusion

Publications

Peak nasal inspiratory flow as outcome for provocation studies in allergen exposure chambers: a GA<sup>2</sup>LEN study.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets

Peak nasal inspiratory flow as outcome for provocation studies in allergen exposure chambers: a GA²LEN study.