Effect of Alveolar Minute Ventilation on Respiratory Gas Heat Content

Completed

• Conditions: Ventilation Perfusion Mismatch
• Interventions: Other: controlled positive pressure ventilation 6ml/kg tidal volume; Other: controlled positive pressure ventilation 9ml/kg tidal volume

• Registration Number: NCT01943227
• Lead Sponsor: University of California, Davis

Brief Summary

This is a single site, prospective, non-blinded, non-randomized, non-interventional study designed to evaluate the effect of changes in alveolar minute ventilation on the measurement of respiratory heat loss (enthalpy).

Detailed Description

This is a single site, prospective, non-blinded, non-randomized, noninterventional study designed to evaluate the effect of changes in alveolar minute ventilation on the measurement of respiratory heat loss (enthalpy). Each patient will serve as their own control. The study will enroll adult patients without cardiac or respiratory illness. It is designed to evaluate the effect of the ventilatory pattern (tidal volume, rate) on respiratory heat loss measured using the VQm™ monitor during standard intra-operative clinical care that requires positive pressure ventilation (PPV)

Study Timeline

• Study Start: 2013-08
• Study First Submitted: 2013-09-11
• Study First Submitted QC: 2013-09-11
• Study First Posted: 2013-09-16
• Primary Completion: 2014-03
• Study Completion: 2014-03
• Results First Submitted: 2014-07-01
• Status Verified: 2019-10
• Results First Submitted QC: 2019-10-08
• Last Update Submitted: 2019-10-08
• Results First Posted: 2019-10-28
• Last Update Posted: 2019-10-28

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 20

Inclusion Criteria

• age greater than 18 years
• scheduled for an elective surgical procedure with an anticipated duration of more than 2 hours requiring general anesthesia and positive pressure ventilation using an endotracheal tube
• patient status ASA 1, 2 or 3
• no significant cardio-vascular or respiratory disease
• supine surgical position

Exclusion Criteria

• Adults unable to give primary consent
• age less than 18 years
• pregnancy
• prisoners
• pre-existing cardiac or pulmonary disease
• infusion of inotropic drugs
• positive end expiratory pressure (PEEP) requirements >8 cm H2O
• increased intra-abdominal pressure (e.g. planned surgical pneumoperitoneum or ascitis)
• intra-operative patient position other than supine

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Arm && Interventions

Group	Intervention	Description
6ml/kg	controlled positive pressure ventilation 6ml/kg tidal volume	Enthalpy measured in patients receiving controlled positive pressure ventilation 6ml/kg Tidal volume. The VQm monitor samples the gas at a rate of 3 L/min, returning the analyzed gas to the circuit. As the exhaled gas passes through the analytical chamber, the temperature and humidity are measured essentially continuously (40Hz). These data are combined with pressure measurements to determine the exhaled gas volume and then the heat content (enthalpy) is calculated.
9ml/kg	controlled positive pressure ventilation 9ml/kg tidal volume	Enthalpy measured in patients receiving controlled positive pressure ventilation 9ml/kg Tidal volume. The VQm monitor samples the gas at a rate of 3 L/min, returning the analyzed gas to the circuit. As the exhaled gas passes through the analytical chamber, the temperature and humidity are measured essentially continuously (40Hz). These data are combined with pressure measurements to determine the exhaled gas volume and then the heat content (enthalpy) is calculated.

Primary Outcome Measures

Name	Time	Method
Airway Enthalpy	12 months	This is a single site, prospective, non-blinded, non-randomized, non-interventional study designed to evaluate the effect of changes in alveolar minute ventilation on the measurement of respiratory heat loss (enthalpy) in Joules per minute.

Trial Locations

Locations (1)

UC Davis Health System; 🇺🇸 Sacramento, California, United States