Infant, Preterm
Conditions
Keywords
mechanical ventilation, diaphragm electrical activity, pressure support
Brief summary
The purpose of this study is to test the hypothesis that neurally adjusted ventilatory assist (NAVA) will allow to lower the ventilator pressure at equivalent fractions of inspiratory oxygen (FiO2) and partial pressure of CO2 of capillary blood in preterm infants in comparison with currently used standard ventilation (synchronized intermittent mandatory ventilation with pressure-support ventilation, SIMV+PSV).
Detailed description
The investigators will apply crossover comparison in preterm infants who received a ventilatory support. In patient whose frequency of mandatory support is under 25, the two ventilatory modes (SIMV+PSV and NAVA) are delivered by the same ventilator (Servo-I; Maquet Critical Care AB, Solna, Sweden) and will set to maintain similar blood gas analysis results. Determination of the type of ventilatory mode used is performed using a cluster randomization. The randomized order of ventilatory mode will be used during total 9 hours; one mode for 4 hours and another mode for 5 hours. To rule out carry-over effects, a 1-hour interval for washout was guaranteed between modes. Recordings will be obtained over a total 8 hours.
Interventions
PROCEDUREneurally adjusted ventilatory assist (NAVA) ventilator mode
Neurally adjusted ventilatory assist (NAVA) utilizes the electrical activity of the diaphragm (EAdi) to trigger and cycle-off breaths, and therefore presents a means of bypassing the ventilator circuit, and the inherent delays with pneumatic triggering. This is a processed signal, which is not artificially influenced by changes in muscle length, chest wall configuration, and/or lung volume. It represents the summation of muscle motor unit recruitment and/or firing rate, and correlates with phrenic nerve activity. In this mode, the amount of support pressure is coupled with the magnitude of the EAdi. The proportion of support pressure to EAdi (NAVA level) is adjustable.
Sponsors
Seoul National University Hospital
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
SUPPORTIVE_CARE
Masking
SINGLE (Subject)
Eligibility
Sex/Gender
ALL
Age
No minimum to 12 Weeks
Healthy volunteers
No
Inclusion criteria
* preterm infants mechanically ventilated * ventilatory set frequency is under 25 * with informed consent of their parents
Exclusion criteria
* major congenital anomalies * patients without self respiratory effort * use of sedative or anesthetic drugs * grade III or IV intraventricular hemorrhage * phrenic nerve palsy or insufficiency
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Peak Inspiratory Pressure | four hours | peak inspiratory pressure measured by a ventilator for 4 hours with each ventilator mode |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Mean Airway Pressure | four hours | mean airway pressure measured by a ventilator for 4 hours with each ventilator mode |
| Minute Ventilation | four hours | Minute ventilation measured by a ventilator for 4 hours with each ventilator mode |
| Expiratory Tidal Volume | four hours | Expiratory tidal volume measured by a ventilator for 4 hours with each ventilator mode |
| Dynamic Compliance | four hours | Dynamic Compliance measured by a ventilator for 4 hours with each ventilator mode |
| Work of Breathing | four hours | Work of breathing of patients measured by a ventilator for 4 hours with each ventilator mode |
| Peak EAdi | four hours | Peak electrical activity of the diaphragm |
| Fraction of Oxygen | four hours | Fraction of oxygen measured by a ventilator for 4 hours with each ventilator mode |
| Capillary Blood pH | four hours | Capillary blood pH checked immediately after the 4-hour respiratory support with each ventilator mode |
| Capillary Blood pCO2 | four hours | Capillary blood pCO2 checked immediately after the 4-hour respiratory support with each ventilator mode |
| Capillary Blood pO2 | four hours | Capillary blood pO2 checked immediately after the 4-hour respiratory support with each ventilator mode |
| Capillary Blood HCO3 | four hours | Capillary blood HCO3 checked immediately after the 4-hour respiratory support with each ventilator mode |
Countries
South Korea
Participant flow
Recruitment details
Participants recruited from a neonatal intensive care unit (NICU) of Seoul National University Hospital, in Seoul, Republic of Korea between March 2011 to July 2011.
Pre-assignment details
26 patients enrolled; 24 assigned to randomization and 2 excluded (1 extubated prior to the study and 1 developed exclusion criteria)
Participants by arm
| Arm | Count |
|---|---|
| SN Group Synchronized intermittent mandatory ventilation (SIMV) with Pressure support (PS) first, then Neurally adjusted ventilatory assist (NAVA) | 13 |
| NS Group NAVA first, then SIMV with PS | 11 |
| Total | 24 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 |
|---|---|---|---|
| Overall Study | Respiratory rate > 80/min during study | 1 | 3 |
| Overall Study | Withdrawal by Subject | 0 | 1 |
Baseline characteristics
| Characteristic | SN Group | NS Group | Total |
|---|---|---|---|
| Age Continuous | 7 days | 5 days | 5 days |
| Birth Height | 37.2 cm STANDARD_DEVIATION 5.9 | 38.3 cm STANDARD_DEVIATION 6.7 | 37.7 cm STANDARD_DEVIATION 6.2 |
| Birth Weight | 990 g | 1630 g | 1075 g |
| Capillary Blood HCO3 | 24.20 mmol/L STANDARD_DEVIATION 3.45 | 21.62 mmol/L STANDARD_DEVIATION 9.34 | 23.02 mmol/L STANDARD_DEVIATION 6.78 |
| Capillary Blood pCO2 | 48.83 mmHg STANDARD_DEVIATION 8.93 | 44.45 mmHg STANDARD_DEVIATION 6.34 | 46.8 mmHg STANDARD_DEVIATION 8 |
| Capillary Blood pH | 7.31 pH STANDARD_DEVIATION 0.04 | 7.34 pH STANDARD_DEVIATION 0.06 | 7.32 pH STANDARD_DEVIATION 0.05 |
| Capillary Blood pO2 | 37.77 mmHg STANDARD_DEVIATION 7.03 | 37.00 mmHg STANDARD_DEVIATION 8.8 | 37.42 mmHg STANDARD_DEVIATION 7.72 |
| Gestational Age | 206 days STANDARD_DEVIATION 28 | 212 days STANDARD_DEVIATION 20 | 209 days STANDARD_DEVIATION 24 |
| Region of Enrollment Korea, Republic of | 13 participants | 11 participants | 24 participants |
| Sex: Female, Male Female | 7 Participants | 0 Participants | 7 Participants |
| Sex: Female, Male Male | 6 Participants | 11 Participants | 17 Participants |
| Study Day Body Weight | 1210 g | 1530 g | 1355 g |
| Study Day Postmenstrual Age | 220 days STANDARD_DEVIATION 20 | 222 days STANDARD_DEVIATION 15 | 221 days STANDARD_DEVIATION 18 |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | — / — | — / — |
| other Total, other adverse events | 0 / 13 | 0 / 11 |
| serious Total, serious adverse events | 0 / 13 | 0 / 11 |
Outcome results
Primary
Peak Inspiratory Pressure
peak inspiratory pressure measured by a ventilator for 4 hours with each ventilator mode
Time frame: four hours
Population: The analysis was per protocol. 19 patients who had completed the study was used for the analysis.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| SIMV With PS | Peak Inspiratory Pressure | 13.45 cmH2O | Standard Deviation 3.44 |
| NAVA | Peak Inspiratory Pressure | 12.45 cmH2O | Standard Deviation 2.66 |
p-value: 0.04395% CI: [0.036, 1.978]Paired t-test
Secondary
Capillary Blood HCO3
Capillary blood HCO3 checked immediately after the 4-hour respiratory support with each ventilator mode
Time frame: four hours
Population: The analysis was per protocol. 19 patients who had completed the study was used for the analysis.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| SIMV With PS | Capillary Blood HCO3 | 24.46 mmol/L | Standard Deviation 3.95 |
| NAVA | Capillary Blood HCO3 | 24.74 mmol/L | Standard Deviation 3.57 |
p-value: 0.695% CI: [-1.35, 0.802]Paired t-test
Secondary
Capillary Blood pCO2
Capillary blood pCO2 checked immediately after the 4-hour respiratory support with each ventilator mode
Time frame: four hours
Population: The analysis was per protocol. 19 patients who had completed the study was used for the analysis.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| SIMV With PS | Capillary Blood pCO2 | 46.75 mmHg | Standard Deviation 7.43 |
| NAVA | Capillary Blood pCO2 | 46.64 mmHg | Standard Deviation 7.87 |
p-value: 0.94995% CI: [-3.505, 3.726]Paired t-test
Secondary
Capillary Blood pH
Capillary blood pH checked immediately after the 4-hour respiratory support with each ventilator mode
Time frame: four hours
Population: The analysis was per protocol. 19 patients who had completed the study was used for the analysis.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| SIMV With PS | Capillary Blood pH | 7.327 pH | Standard Deviation 0.051 |
| NAVA | Capillary Blood pH | 7.334 pH | Standard Deviation 0.046 |
p-value: 0.51595% CI: [-0.03, 0.016]Paired t-test
Secondary
Capillary Blood pO2
Capillary blood pO2 checked immediately after the 4-hour respiratory support with each ventilator mode
Time frame: four hours
Population: The analysis was per protocol. 19 patients who had completed the study was used for the analysis.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| SIMV With PS | Capillary Blood pO2 | 38.89 mmHg | Standard Deviation 8.82 |
| NAVA | Capillary Blood pO2 | 37.84 mmHg | Standard Deviation 8.51 |
p-value: 0.70995% CI: [-4.77, 6.875]Paired t-test
Secondary
Dynamic Compliance
Dynamic Compliance measured by a ventilator for 4 hours with each ventilator mode
Time frame: four hours
Population: The analysis was per protocol. 19 patients who had completed the study was used for the analysis.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| SIMV With PS | Dynamic Compliance | 1.70 mL/cmH2O | Standard Deviation 0.47 |
| NAVA | Dynamic Compliance | 1.84 mL/cmH2O | Standard Deviation 0.36 |
p-value: 0.08595% CI: [-0.32, 0.023]Paired t-test
Secondary
Expiratory Tidal Volume
Expiratory tidal volume measured by a ventilator for 4 hours with each ventilator mode
Time frame: four hours
Population: The analysis was per protocol. 19 patients who had completed the study was used for the analysis.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| SIMV With PS | Expiratory Tidal Volume | 8.73 mL/Kg | Standard Deviation 2.08 |
| NAVA | Expiratory Tidal Volume | 8.54 mL/Kg | Standard Deviation 2.24 |
p-value: 0.60195% CI: [-0.554, 0.931]Paired t-test
Secondary
Fraction of Oxygen
Fraction of oxygen measured by a ventilator for 4 hours with each ventilator mode
Time frame: four hours
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| SIMV With PS | Fraction of Oxygen | 23.33 percentage of concentration |
| NAVA | Fraction of Oxygen | 23.47 percentage of concentration |
p-value: 0.31495% CI: [-0.364, 1.749]Wilcoxon signed-rank test
Secondary
Mean Airway Pressure
mean airway pressure measured by a ventilator for 4 hours with each ventilator mode
Time frame: four hours
Population: The analysis was per protocol. 19 patients who had completed the study was used for the analysis.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| SIMV With PS | Mean Airway Pressure | 7.99 cmH2O | Standard Deviation 1.33 |
| NAVA | Mean Airway Pressure | 8.02 cmH2O | Standard Deviation 1.23 |
p-value: 0.24595% CI: [-0.637, 0.174]Paired t-test
Secondary
Minute Ventilation
Minute ventilation measured by a ventilator for 4 hours with each ventilator mode
Time frame: four hours
Population: The analysis was per protocol. 19 patients who had completed the study was used for the analysis.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| SIMV With PS | Minute Ventilation | 0.53 L/min/Kg | Standard Deviation 0.15 |
| NAVA | Minute Ventilation | 0.51 L/min/Kg | Standard Deviation 0.11 |
p-value: 0.25795% CI: [-0.02, 0.714]Paired t-test
Secondary
Peak EAdi
Peak electrical activity of the diaphragm
Time frame: four hours
Population: The analysis was per protocol. 19 patients who had completed the study was used for the analysis.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| SIMV With PS | Peak EAdi | 13.39 uV | Standard Deviation 5.68 |
| NAVA | Peak EAdi | 11.70 uV | Standard Deviation 5.72 |
p-value: 0.00995% CI: [0.478, 2.904]Paired t-test, 2-sided
Secondary
Work of Breathing
Work of breathing of patients measured by a ventilator for 4 hours with each ventilator mode
Time frame: four hours
Population: The analysis was per protocol. 19 patients who had completed the study was used for the analysis.
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| SIMV With PS | Work of Breathing | 11.13 mJ/L |
| NAVA | Work of Breathing | 8.38 mJ/L |
p-value: 0.00295% CI: [1.799, 11.232]Wilcoxon signed-rank test