Effect of Alveolar Minute Ventilation on Respiratory Gas Heat Content

• Sponsor: University of California, Davis (Other)
• Overall Status: Completed
• CT.gov ID: NCT01943227
• Collaborator: (none)
• Enrollment: 20
• Location: 1
• Duration (Months): 7
• Patients Per Site Per Month: 2.9

Study Details

Study Description

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).

Condition or Disease	Intervention/Treatment	Phase
Ventilation Perfusion Mismatch	Other: controlled positive pressure ventilation 9ml/kg tidal volume; Other: controlled positive pressure ventilation 6ml/kg tidal volume

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 Design

• Study Type: Observational
• Actual Enrollment: 20 participants
• Observational Model: Cohort
• Time Perspective: Prospective
• Official Title: Effect of Alveolar Minute Ventilation on Respiratory Gas Heat Content
• Study Start Date: Aug 1, 2013
• Actual Primary Completion Date: Mar 1, 2014
• Actual Study Completion Date: Mar 1, 2014

Arms and Interventions

Arm	Intervention/Treatment
6ml/kg 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.	Other: controlled positive pressure ventilation 6ml/kg tidal volume; controlled positive pressure ventilation 6ml/kg tidal volume
9ml/kg 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.	Other: controlled positive pressure ventilation 9ml/kg tidal volume; controlled positive pressure ventilation 9ml/kg tidal volume

Outcome Measures

Primary Outcome Measures

1. 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.

Eligibility Criteria

Criteria

• Ages Eligible for Study: 18 Years and Older
• Sexes Eligible for Study: All
• Accepts Healthy Volunteers: No

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

Contacts and Locations

Locations

	Site	City	State	Country	Postal Code
1	UC Davis Health System	Sacramento	California	United States	95817

Sponsors and Collaborators

• University of California, Davis

Investigators

• Principal Investigator: Neal Fleming, MD, PhD, Professor, Anesthesiology & Pain Medicine

Study Documents (Full-Text)

None provided.

More Information

Publications

None provided.

• Responsible Party: University of California, Davis
• ClinicalTrials.gov Identifier: NCT01943227
• Other Study ID Numbers: 483184
• First Posted: Sep 16, 2013
• Last Update Posted: Oct 28, 2019
• Last Verified: Oct 1, 2019

• Keywords provided by University of California, Davis: humidity; enthalpy; mechanical ventilation

Study Results

Participant Flow

Recruitment Details	Patient recruitment and informed consent will be obtained in the UCDMC perioperative suite. Recruitment will be by direct discussion between the prospective candidates and the study investigators prior to their scheduled surgical procedure. The investigators will provide the consent form in person and give subject time to discuss with family.
Pre-assignment Detail	The screening of patients will require the investigators to access personal health information to identify prospective subjects without HIPAA authorization. The research could not be practicably carried out without this waiver of consent. The risk of harm from contacting the participants is greater than the risk of the study procedures.

Arm/Group Title	Large Tidal Volume	Smal Tidal Volume
Arm/Group Description	Change in airway heat content	Change in airway heat content
Period Title: Overall Study
STARTED	10	10
COMPLETED	10	10
NOT COMPLETED	0	0

Baseline Characteristics

Arm/Group Title	Large Tidal Volume	Small Tidal Volume	Total
Arm/Group Description	Airway heat content	Airway heat content	Total of all reporting groups
Overall Participants	10	10	20
Age (Count of Participants)
<=18 years	0 0%	0 0%	0 0%
Between 18 and 65 years	10 100%	10 100%	20 100%
>=65 years	0 0%	0 0%	0 0%
Age (Years) [Mean (Standard Deviation) ]
Mean (Standard Deviation) [Years]	44 (10.8)	42 (13.8)	43 (12.5)
Sex: Female, Male (Count of Participants)
Female	6 60%	3 30%	9 45%
Male	4 40%	7 70%	11 55%
Region of Enrollment (participants) [Number]
United States	10 100%	10 100%	20 100%

Outcome Measures

1. Primary Outcome

Title	Airway Enthalpy
Description	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.
Time Frame	12 months

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	Large Tidal Volume	Smal Tidal Volume
Arm/Group Description	Change in airway heat content	Change in airway heat content
Measure Participants	10	10
Mean (Standard Deviation) [Joules/Minute]	32 (9.1)	23 (8.9)

Adverse Events

Time Frame	24 hours
Arm/Group Title	Large Tidal Volume		Small Tidal Volume
Arm/Group Description	Airway heat content		Airway heat content
All Cause Mortality
	Large Tidal Volume		Small Tidal Volume
	Affected / at Risk (%)	# Events	Affected / at Risk (%)	# Events
Total	0/10 (0%)		0/10 (0%)
Serious Adverse Events
	Large Tidal Volume		Small Tidal Volume
	Affected / at Risk (%)	# Events	Affected / at Risk (%)	# Events
Total	0/10 (0%)		0/10 (0%)
Other (Not Including Serious) Adverse Events
	Large Tidal Volume		Small Tidal Volume
	Affected / at Risk (%)	# Events	Affected / at Risk (%)	# Events
Total	0/10 (0%)		0/10 (0%)

Limitations/Caveats

[Not Specified]

More Information

Certain Agreements

All Principal Investigators ARE employed by the organization sponsoring the study.

There is NOT an agreement between Principal Investigators and the Sponsor (or its agents) that restricts the PI's rights to discuss or publish trial results after the trial is completed.