PEP-device for Treatment of Swimming-induced Pulmonary Edema (SIPE)

Evaluation of Positive Expiratory Pressure Device (PEP-device) for Treatment of Swimming Induced Pulmonary Edema (SIPE) - a Randomized Single-blinded Controlled Study

In swimming induced pulmonary edema (SIPE), there is a lack of knowledge regarding optimal treatment. The present study was designed to assess the benefit of treatment with positive expiratory pressure device (PEP-device) compared to spontaneous recovery in patients with SIPE without hypoxia in the out-of-hospital environment.

Swimming induced pulmonary edema (SIPE) is an unusual condition affecting otherwise healthy swimmers. SIPE is characterized by acute onset of dyspnea and cough, excessive sputum and occasionally hemoptysis when swimming in open water. The condition usually resolves spontaneously within 48 hours, but may result in serious illness and require emergency care. Case reports describe acute treatment with or without oxygen in combination with diuretics, beta-agonist-inhalation or continuous positive airway pressure (CPAP). Evidence for optimal treatment strategy is lacking. Oxygen treatment might not be appropriate for patients with SIPE presenting without hypoxia. It is unknown if positive airway pressure accelerates recovery in SIPE. This study intends to determine whether treatment with positive expiratory pressure (PEP) applied by PEP-device accelerates increase of oxygen saturation compared to spontaneous recovery in patients presenting with SIPE without hypoxia. The aim is to treat patients on site without involving hospital care. We study a large cohort of approximately 12 000 swimmers during Vansbrosimningen, Sweden's biggest annual open water event with a yearly incidence of SIPE about 0,4%. Adult patients clinically diagnosed with SIPE and oxygen saturation ≥92% are randomly assigned to 2 groups: (1) PEP-device for 20 minutes or (2) control group with spontaneous recovery without active treatment for 20 minutes. Assessment with outcome measures is taken 10 minutes after intervention/control. Primary endpoint: oxygen saturation (%) by pulse oxymetry.

Positive expiratory pressure device: continuous treatment with PEP-device breathing air for 20 minutes followed by 10 minutes rest and assessment. Inspiration through nose/mouth, expiration through device.

Change in peripheral oxygen saturation % (continuous variable) measured by pulse oximetry before and after treatment

Recovery, defined by "peripheral oxygen saturation >95% after treatment" or no recovery, defined by "peripheral oxygen saturation ≤95% after treatment"

Four chest regions for both lungs are scanned by lung ultrasound; a positive region defined by the presence of three or more B-line artifacts. Bilateral or unilateral presence of two or more positive regions define positive interstitial syndrome

Four chest regions for both lungs are scanned by lung ultrasound; a positive region defined by the presence of three or more B-line artifacts. Assessment of the total number of positive regions.

Change in absolute number of regions presenting B-lines on lung ultrasound before and after treatment

Four chest regions for both lungs are scanned by lung ultrasound; a positive region defined by the presence of three or more B-line artifacts. Assessment of the total number of positive regions. Change in absolute number of regions presenting B-lines on lung ultrasound before and after treatment

Six different patient reported outcome measures assessed by numerical rating scale (NRS; min-max 0-10): cough, sputum, air hunger, breathing effort, tightness in chest, anxiousness. The patients will assess symptoms prior to and after treatment

Inclusion Criteria: clinical diagnosis of swimming induced pulmonary edema (SIPE) with need of acute treatment peripheral oxygen saturation ≥92% 18 years or older informed consent Exclusion Criteria: declined consent suspected acute coronary syndrome severe asthma diagnosed together with pulmonary edema with requirement of beta-agonist-inhalation prior to treatment of pulmonary edema hemodynamic instability or decreased consciousness