The Incidence of Subclinical High-altitude Pulmonary Oedema at High Altitude

The aim of this investigation is to determine the incidence of silent interstitial pulmonary edema by chest ultrasound at moderate altitude (3905m). Secondary endpoints are to detect a suspected association with acute mountain sickness (AMS), co-morbidities and endothelial dysfunction (marker of hypoxia responses, endothelial damage and inflammation).

Study Overview

• Status: Completed
• Conditions: Acute Mountain Sickness; Subclinical High Altitude Pulmonary Edema

Detailed Description

The high-altitude pulmonary edema (HAPE) is the leading cause of death from high altitude sickness. At moderate altitude (2500-4500m) the incidence (0.2-6%) may be underestimated because only clinical HAPE leads to symptoms and motivates the patient to seek medical advice. Cremona et al. [Cremona et al. Pulmonary extravascular fluid accumulation in recreational climbers: a prospective study. Lancet 2002;359:303-09] suggested that a silent interstitial pulmonary edema arises in most recreational climbers at moderate altitude. Recently, chest sonography has been shown to effectively detect pulmonary edema and quantify extravascular lung water through the sign of "ultrasound lung comets" (ULCs) originating from water-thickened interlobular septa [Lichtenstein D et al. The comet-tail artifact. An ultrasound sign of alveolar-interstitial syndrome. Am J Respir Crit Care Med;156:1640-46]. The technique requires only basic twodimensional technology and has been applied in extreme, out-of-hospital setting, showing in recreational climbers a high prevalence of clinically silent interstitial pulmonary edema at high-altitude [Pratali L et al. Frequent subclinical high-altitude pulmonary edema detected by chest sonography as ultrasound lung comets in recreational climbers. Crit Care Med 2010;38:1818-23]. However, data for moderate altitude remain scarce, despite that mountaineers are increasing in age and comorbidities and could be more prone to high altitude emergencies.

Prospective, non-randomised, observational study. Study participants are recruited from a scientific research group lead by the Ohio State University during a glaciology study on the Ortles Glacier in South Tyrol (3905m).

Patients are tested for a baseline measure, during a permanent stay on the glacier camp (3h, 9h, 24h, 48h, 72h, 7d ). Parameters include chest ultrasound, Lake Louise score, cerebral sensitive score, non-invasive haemodynamic parameters (i.e. US) and markers of hypoxia responses, endothelial damage and inflammation.

• Study Type: Observational
• Enrollment (Actual): 24

Contacts and Locations

Study Locations

• Italy
  • Provincia autonoma di Bolzano
    • Bolzano, Provincia autonoma di Bolzano, Italy, 39100
      • Institute of Mountain Emergency Medicine, EURAC Research

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Healthy adults

Description

Inclusion Criteria:

• healthy of age >18y

Exclusion Criteria:

• cardiac failure
• chronic kidney disease
• chronic pulmonary disease
• acute lung/heart/kidney/brain conditions
• neoplastic disease
• lack of consent

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Changes in the number of beta-lines in chest sonography	as marker of subclinical pulmonary edema	at 0 (arrival at 3830m), 9, 24, 48 and 72 hours, and at day 7

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Changes from baseline of optic nerve sheath diameter	evaluated by optical nerve sonography	at 0 (arrival at 3830m), 3, 9, 24, 48 and 72 hours, and at day 7
Changes from baseline in RNA expression in circulating polymorphonucleated		at 9, 24, 72 hours and day 7

Collaborators and Investigators

• Sponsor: Institute of Mountain Emergency Medicine
• Investigators: Study Director: Giacomo Strapazzon, MD, Institute of Mountain Emergency Medicine, EURAC Research

Study record dates

Study Major Dates

• Study Start: July 1, 2011
• Primary Completion (Actual): July 1, 2011
• Study Completion (Actual): July 1, 2011

Study Registration Dates

• First Submitted: February 14, 2013
• First Submitted That Met QC Criteria: February 15, 2013
• First Posted (Estimate): February 18, 2013

Study Record Updates

• Last Update Posted (Estimate): February 18, 2013
• Last Update Submitted That Met QC Criteria: February 15, 2013
• Last Verified: February 1, 2013

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Cardiovascular Diseases; Vascular Diseases; Respiratory Tract Diseases; Respiration Disorders; Lung Diseases; Hypertension; Altitude Sickness; Hypertension, Pulmonary; Edema; Pulmonary Edema
• Other Study ID Numbers: V/4/11