Pleth Variability and Asthma Severity in Children

Study Overview
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Brief Summary
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Research has shown that pleth variability can be used to assess asthma severity in children with status asthmaticus. The investigators would like to use an FDA-cleared monitor (Masimo Radical 7) which measures Pleth Variability Index (PVI) to see if the degree of PVI can be used to help triage patients who present to the pediatric ED in status asthmaticus.

Detailed Description
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Patients with asthma have obstruction to exhalation resulting in hyperinflation of their lungs. This hyperinflation results in a phenomenon known as pulsus paradoxus in which the physiologic drop in blood pressure normally seen with inhalation is exaggerated. Studies have shown that patients with more severe asthma exacerbations (i.e. more hyperinflation) have a greater degree of pulsus paradoxus. Typically, pulsus paradoxus is measured using a sphygmomanometer, however, researchers have demonstrated that it can also accurately be measured using plethysmography, a term known as pleth variability index (PVI). Using this concept, Arnold et al (2008, 2010) showed that a greater degree of pulsus paradoxus correlates with asthma severity. The investigators' study aims to simplify the association between PVI and asthma severity. The investigators hypothesize the following: Patients with a higher admission PVI will have a higher likelihood of being admitted to the hospital. Patients admitted to the Intensive Care Unit (PICU) will have a higher PVI than patients admitted to a floor. PVI can be accurately used to gauge response to bronchodilator/anti-inflammatory therapy. PVI is as effective as respiratory severity score in predicting asthma severity and in gauging response to bronchodilator therapy. To do this the investigators will recruit children who present to the pediatric ED in status asthmaticus. They will be connected to a Masimo Radical 7 monitor upon admission to the ED and then again 4 hours later. In addition the investigators will calculate respiratory severity scores at those same time intervals. The investigators will then look at the disposition of the patient upon leaving the ED: discharge to home, admission to an inpatient floor or admission to the ICU.

Official Title
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Using Pleth Variability to Triage Asthmatics in the Pediatric ED

Conditions
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Status Asthmaticus

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Diagnosis of asthma or reactive airway disease upon leaving the ED Greater than 10 kg Exclusion Criteria: Patients in whom effective pulse oximetry tracings cannot be obtained Patients who are diagnosed with conditions other than asthma/reactive airway disease that are known to cause pulsus paradoxus

Ages Eligible for Study
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Maximum Age: 17 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Status Asthmaticus<br>Any patient presenting to the ED with status asthmaticus. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Disposition from ED | Determine whether a patient was discharged from the ED, admitted to an inpatient floor or admitted to the ICU. | 4 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Comparison to respiratory severity score | Is PVI as effective as RSS in determining asthma severity | 4 hours | 
| Change in disposition within 24 hours | Determine if a patient who was discharged home from the ED required readmission to the ED within 1 week. Determine if a patient admitted to the floor or ICU required a change in level of care in the first 24 hours of admission. | 1 week | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Pulsus paradoxus