Prevention and Treatment of Immersion Pulmonary Edema

Study Overview
=================
Brief Summary
-----------------
Immersion pulmonary edema (IPE) is a condition in which fluid fills the lungs during diving or swimming, particularly in cold water. Some individuals appear to be predisposed to developing IPE. DNA samples will be collected and stored, in order to compare the genetic profiles of individuals who have experienced IPE with those who have not. In a few individuals who have experienced IPE, we plan to measure the effects of cold water immersion on the blood pressure, cardiac output and the pressures in the pulmonary artery. These will be compared with similar measurements already obtained from normal individuals.

Detailed Description
-----------------
Immersion pulmonary edema (IPE) is a condition that has sudden onset in swimmers and divers, and is characterized by cough, shortness of breath, decreased blood oxygen levels, and hemoptysis. The purpose of this study is to examine the effects of cold water immersion and the dive reflex on pulmonary arterial pressure and pulmonary capillary wedge pressure in those who have already experienced IPE, as well as explore the possibility of a genetic predisposition. Healthy nonsmoking subjects who have experienced IPE will be recruited for several cold-water immersion experiments and DNA analysis. Their pulmonary arterial and pulmonary arterial wedge pressures will be measured as they undergo immersed rest and exercise trials in thermoneutral and cold water. If the pressures increase with these trials as hypothesized, the effects of sildenafil administration (a pulmonary vasodilator) will be tested during a second trial. Blood will also be drawn for DNA analysis of certain genes with possible relation to IPE. Results of these tests will be compared with those of the general population.

Official Title
-----------------
Effects of the Dive Reflex on Pulmonary Arterial and Pulmonary Artery Wedge Pressures in Subjects Who Have Experienced Immersion Pulmonary Edema

Conditions
-----------------
Immersion Pulmonary Edema (IPE), Swimming Induced Pulmonary Edema (SIPE)

Intervention / Treatment
-----------------
* Drug: Sildenafil


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: History of immersion pulmonary edema Exclusion Criteria: Coronary artery disease, cardiomyopathy, heart valve disease

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 55 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Prevention
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Sildenafil<br>Measurements of pulmonary and systemic pressures during cold water immersion before and after sildenafil 50 mg orally. | Drug: Sildenafil<br>* After measurement of the effect of cold water on cardiac output and pulmonary artery and wedge pressures, a single dose of sildenafil (50 mg) will be given orally, followed by similar hemodynamic measurements.<br>* Other names: Viagra;|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pulmonary artery pressure during cold water immersion |  | 1 day | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Immersion pulmonary edema, Diving, Swimming, Pulmonary edema, Cold water immersion