Do Changes in Plasma Osmolality Influence Ventilation? (OSM)

Do Plasma Osmolality Changes Influence Ventilation, and Are There Gender Differences?

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.

Study Overview

• Status: Completed
• Conditions: Hypernatraemia; Hyponatraemia
• Intervention / Treatment: Other: Water; Other: Saline 3%

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 Type: Interventional
• Enrollment (Actual): 26
• Phase: Early Phase 1

Contacts and Locations

Study Locations

• Sweden
  • Kalmar, Sweden, 39185
    • Department of Anaesthesia and Intensive care, Kalmar County Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 45 years (Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

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 Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Non-Randomized
• Interventional Model: Factorial Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Saline; The subjects will receive saline 3% intravenously for 2 hours, the volume calculated as 0.1 ml/kg/min.	Other: Water; The subjects will drink tap water for 2 hours, volume calculated according to weight: 20ml/kg/hour.; Other Names: saline 3%; Other: Saline 3%; The subjects will receive saline 3% intravenously for 2 hours, the volume calculated as 0.1 ml/kg/min
Experimental: Water; The subjects will drink tap water for 2 hours, the volume calculated as 20ml/kg/hour	Other: Water; The subjects will drink tap water for 2 hours, volume calculated according to weight: 20ml/kg/hour.; Other Names: saline 3%; Other: Saline 3%; The subjects will receive saline 3% intravenously for 2 hours, the volume calculated as 0.1 ml/kg/min

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
pCO2	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.	ten minutes

Collaborators and Investigators

• Sponsor: Vibeke Moen
• Investigators: Study Director: Lars Irestedt. MD PhD, Department of Anaesthesia and Intensive Care , Karolinska University Hospital, Stockholm

Publications and helpful links

General Publications

• Jennings DB. The physicochemistry of [H+] and respiratory control: roles of PCO2, strong ions, and their hormonal regulators. Can J Physiol Pharmacol. 1994 Dec;72(12):1499-512. doi: 10.1139/y94-216.
• Weissgerber TL, Wolfe LA, Hopkins WG, Davies GA. Serial respiratory adaptations and an alternate hypothesis of respiratory control in human pregnancy. Respir Physiol Neurobiol. 2006 Aug;153(1):39-53. doi: 10.1016/j.resp.2005.09.004. Epub 2005 Nov 28.
• Heenan AP, Wolfe LA. Plasma osmolality and the strong ion difference predict respiratory adaptations in pregnant and nonpregnant women. Can J Physiol Pharmacol. 2003 Sep;81(9):839-47. doi: 10.1139/y03-072.

Study record dates

Study Major Dates

• Study Start: November 1, 2009
• Primary Completion (Actual): November 1, 2010
• Study Completion (Actual): November 1, 2010

Study Registration Dates

• First Submitted: November 5, 2009
• First Submitted That Met QC Criteria: November 5, 2009
• First Posted (Estimate): November 6, 2009

Study Record Updates

• Last Update Posted (Estimate): October 17, 2012
• Last Update Submitted That Met QC Criteria: October 15, 2012
• Last Verified: October 1, 2012

More Information

Terms related to this study

• Keywords: ventilation; carbon dioxide; gender; osmolality; menstruation cycle
• Additional Relevant MeSH Terms: Metabolic Diseases; Water-Electrolyte Imbalance; Hyponatremia; Hypernatremia
• Other Study ID Numbers: M-126-09