Do Changes in Plasma Osmolality Influence Ventilation?

Early Phase 1

Completed

• Conditions: Hyponatraemia; Hypernatraemia
• Interventions: Other: Water; Other: Saline 3%

• Registration Number: NCT01008644
• Lead Sponsor: Vibeke Moen

Brief Summary

Primary hypothesis: osmolality changes influence the sensitivity of the respiratory center to carbon dioxide, hyponatraemia causing hyperventilation, and hypernatraemia depressing ventilation.

Secondary hypothesis: There are gender differences in the sensitivity to osmolality changes.

10 women and 10 men will on different occasions drink water or receive hypertonic saline intravenously, in order to lower or increase plasma osmolality. The women will participate during both faces of the menstruation cycle. On each occasion the subject´s sensitivity to carbon dioxide will be tested, and blood samples will be drawn for analysis of blood gases,electrolyte and osmolality.Subjects who interrupt participation before completion of all planned occasions, will be substituted, so that 10 subjects of either sex will have participated as planned. All results from all participants will be analyzed.

Detailed Description

Healthy volunteers will on different occasions be subject to reduced plasma osmolality caused by drinking water, and increased osmolality caused by intravenous infusion of hypertonic saline.Before and after each osmolality change, sensitivity to carbon dioxide will be tested by partial rebreathing through a so called Bain-system. Throughout the whole experiment heart rate, blood pressure and oxygen saturation will be recorded.Blood samples will be collected before each rebreathing test and every 20 minutes during the two hours of water or salt load. Urine will be collected and analysed.

Study Timeline

• Study Start: 2009-11
• Study First Submitted: 2009-11-05
• Study First Submitted QC: 2009-11-05
• Study First Posted: 2009-11-06
• Primary Completion: 2010-11
• Study Completion: 2010-11
• Status Verified: 2012-10
• Last Update Submitted: 2012-10-15
• Last Update Posted: 2012-10-17

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 26

Inclusion Criteria

• Females with regular menstruations, males

Exclusion Criteria

• Consumption of nicotine, BMI > 26,
• pregnancy,any hormone treatment,
• treatment with diuretics,
• diabetes or kidney disease,
• BMI > 26,

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: FACTORIAL

Arm && Interventions

Group	Intervention	Description
Water	Saline 3%	The subjects will drink tap water for 2 hours, the volume calculated as 20ml/kg/hour
Saline	Saline 3%	The subjects will receive saline 3% intravenously for 2 hours, the volume calculated as 0.1 ml/kg/min.
Saline	Water	The subjects will receive saline 3% intravenously for 2 hours, the volume calculated as 0.1 ml/kg/min.
Water	Water	The subjects will drink tap water for 2 hours, the volume calculated as 20ml/kg/hour

Primary Outcome Measures

Name	Time	Method
pCO2	ten minutes	pCO2,osmolality and sensitivity to CO2 will be recorded 10 minutes before before and 10 minutes after administering water or saline for two hours.The results will be analyzed for differences before and after osmolality changes in every single individual, and differences between females in luteal or follicular menstruation phase.

Trial Locations

Locations (1)

Department of Anaesthesia and Intensive care, Kalmar County Hospital; 🇸🇪 Kalmar, Sweden