Ventilation Perfusion Mismatch
Conditions
Keywords
humidity, enthalpy, mechanical ventilation
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)
Interventions
OTHERcontrolled positive pressure ventilation 9ml/kg tidal volume
controlled positive pressure ventilation 9ml/kg tidal volume
OTHERcontrolled positive pressure ventilation 6ml/kg tidal volume
controlled positive pressure ventilation 6ml/kg tidal volume
Sponsors
University of California, Davis
Study design
Observational model
COHORT
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| 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. |
Countries
United States
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 details
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.
Participants by arm
| Arm | Count |
|---|---|
| Large Tidal Volume Airway heat content | 10 |
| Small Tidal Volume Airway heat content | 10 |
| Total | 20 |
Baseline characteristics
| Characteristic | Small Tidal Volume | Large Tidal Volume | Total |
|---|---|---|---|
| Age, Categorical <=18 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical >=65 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical Between 18 and 65 years | 10 Participants | 10 Participants | 20 Participants |
| Age, Continuous | 42 Years STANDARD_DEVIATION 13.8 | 44 Years STANDARD_DEVIATION 10.8 | 43 Years STANDARD_DEVIATION 12.5 |
| Region of Enrollment United States | 10 participants | 10 participants | 20 participants |
| Sex: Female, Male Female | 3 Participants | 6 Participants | 9 Participants |
| Sex: Female, Male Male | 7 Participants | 4 Participants | 11 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 0 / 10 | 0 / 10 |
| other Total, other adverse events | 0 / 10 | 0 / 10 |
| serious Total, serious adverse events | 0 / 10 | 0 / 10 |
Outcome results
Primary
Airway Enthalpy
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
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Large Tidal Volume | Airway Enthalpy | 32 Joules/Minute | Standard Deviation 9.1 |
| Smal Tidal Volume | Airway Enthalpy | 23 Joules/Minute | Standard Deviation 8.9 |