Analgesia Nociception Index In Pediatric Patients With Chronic Pain

Inclusion Criteria: * Experiencing chronic pain defined by: persistent or recurrent pain at least once a week for at least three months in their electronic medical charts or by reference of the patient's physician Exclusion Criteria: * Taking medications known to affect the sympathetic or parasympathetic nervous systems such as cholinomimetics (e.g., pilocarpine), anticholinergics (e.g., ipratropium), sympathomimetics (e.g., salbutamol), and adrenergic antagonists (e.g., propranolol). * Diagnosed cardiac or neurological conditions, including patients with arrhythmias, heart block, postural orthostatic tachycardia syndrome, Guillain-Barre syndrome, or spinal cord injury. * Active cancer diagnosis * Conditions that may interfere with the ability to understand instructions or complete assessments including: cognitive, or developmental delay. * Patients who do not speak English or French.