89 - Diagnostic Utility and Safety of Continuous Laryngoscopy During Cardiopulmonary Exercise Testing in Pediatric Patients

Publication Number: 4087.89

Andreas Kreutzer, Cook Children's Medical Center, Prosper, TX, United States; John M.. Robertson, Cook Children's Medical Center - Prosper, Frisco, TX, United States; Rebecca Brovina, Cook Children's, Prosper, TX, United States

Background: Exercise-induced respiratory symptoms (EIRS) limit physical activity and sport performance in adolescents. They are common in the general population (15%) and athletes (>20%). Exercise-induced bronchoconstriction (EIB) is the leading cause of EIRS in adolescents. When EIB treatment fails, accurate diagnosis is often arduous. Other causes of EIRS include exercise-induced laryngeal obstruction (EILO), dysfunctional breathing (EIDB), and cardiovascular pathologies. The gold standard for diagnosing EILO is continuous laryngoscopy during exercise (CLE), where a flexible nasolaryngoscope provides real-time video of the larynx. We combine CLE with a cardiopulmonary exercise test (CLE-CPET) for simultaneous upper airway, respiratory, and cardiovascular evaluation.

Objective: The objective of this ongoing QI project is to evaluate safety, feasibility, and diagnostic success of CLE-CPET in pediatric patients at the Cook Children's Exercise Respiratory Center.

Design/Methods: We present data from our first 107 CLE-CPET patients (sex: f = 69, m = 38; age: 14.3 ± 2.3 years [range: 8-18]). They were competitive athletes (72.9%) or recreational exercisers (27.1%). Forty-four (41.1%) had a prior diagnosis of asthma and 69 (64.5%) had been prescribed asthma medication.

Results: We completed 102 (95.3%) of the 107 attempted CLE-CPET, including eight patients under the age of 11. Four patients were unable to tolerate the laryngoscopy; one was unable to reach peak exercise due to prior fatigue. We provided diagnoses for 99 (91.6%) patients. Forty-nine (45.8%) patients had EILO. EIDB was present in 87 (81.3%) patients and was comorbid with EILO in 38. Nine (84%) patients had EIB; five of these also had EILO, and two had all three conditions. One patient experienced syncope during exercise and two experienced near-syncope during recovery. These three patients had been referred for these syncopal/near-syncopal events. No patients experienced adverse events directly caused by the procedure. Eighty-three patients (77.6%) had a resting echocardiogram and 85 (79.4%) a resting electrocardiogram before the CLE-CPET. Nine patients (8.4%) had a cardiovascular diagnosis. Hemoglobin measurements were available for 68 patients (f = 45, m = 23). Two female patients had anemia.

Conclusion(s): Our current diagnostic approach using a CLE-CPET with pre- and post-spirometry has allowed us to safely achieve a diagnosis in almost all of our patients. The vast majority of patients tolerated the procedure well.

Experimental Setup
Experimental setup for our combined continuous laryngoscopy during exercise and cardiopulmonary exercise test (CLE-CPET). ***Not an actual patient test. Data on screens are AI-generated for illustrative purposes only.

Descriptive Statistics
Descriptive statistics for all 107 patients included in the project. BMI = Body Mass Index; EILO = Exercise-Induced Laryngeal Obstruction; EIDB = Exercise Induced Dysfunctional Breathing; EIB = Exercise-Induced Bronchoconstriction. a: Percentages of EILO subtypes are in reference to the total number of patients with EILO rather than the total sample

Venn Diagram of CLE-CPET Diagnoses
Venn diagram showing diagnoses obtained from the CLE-CPET. EIB = Exercise-Induced Laryngeal Obstruction; EIDB = Exercise-Induced Dysfunctional Breathing; EILO = Exercise-Induced Laryngeal Obstruction.