Physiological Dead Space Measured by Volumetric Capnography, Is it Different Between the Biphasic Positive Airway Pressure Mode ( BiPAP ) and Airway Pressure Release Ventilation Mode ( APRV ) ? A Randomized Controlled Study.
试验速览
- 阶段
- 不适用
- 发起方
- 入组人数
- 60
- 试验地点
- 1
- 主要终点
- Physiological dead space
研究概览
简要总结
Background and Rationale :
Mechanical ventilation is an essential component of the care of patients with respiratory failure.Biphasic positive Airway Pressure (BiPAP) and Airway Pressure release ventilation (APRV) are relatively new modes of mechanical ventilation which can be used in treatment of patients with impaired oxygenation.The effect of using BiPAP and APRV modes on reducing the physiological dead space had not been previously investigated. The investigators hypothesize that using APRV mode will decrease physiological dead space more than BiPAP mode in the mechanically ventilated critically ill patients.
Objectives :
To assess the physiological dead space with each mode. To assess lung mechanics during the use of the two modes. To assess the effectiveness of ventilation during the use of the two modes.
Study population & Sample size :
Sixty adult patients more than 18 years old who are mechanically ventilated patients with P/F ratio less than 300. This sample size was calculated based on the assumption that APRV will decrease dead space by 20% with alpha error 0.05 and power 80%. The mean and Standard deviation of the volume of the dead space assessed in a previous study using BIPAP was 40
Study Design :
A randomized controlled non-blinded study with cross-over design. In the Trauma and surgical ICU at 185-Hospital (Kasr Alainy Hospitals).
Methods :
All mechanically ventilated patients in Trauma and surgical ICU at 185-Hospital (Kasr Alainy Hospitals) will start on pressure controlled ventilation mode (PCV) with inspiratory pressure achieving tidal volume 6-8 ml/kg for 2 hours then they will be randomized into one of the two study groups the BIPAP group or the APRV group .
Possible Risk (s) to study population :
By adjusting the ventilator parameters properly and continuous monitoring of the patients in the study, there will be no risk facing the patients.
Outcome parameter (s):
Primary outcome: Physiological dead space will be measured in the two groups after 30 minutes.
Secondary outcomes
- Physiological dead space after 3 hours.
- PO2/FiO2 ratio.
- Peak airway and Mean airway pressures.
- PCO2 and PH.
- Dynamic compliance.
详细描述
All mechanically ventilated patients in Trauma and surgical ICU at 185-Hospital (Kasr Alainy Hospitals) will start on pressure controlled ventilation mode (PCV) with inspiratory pressure achieving tidal volume 6-8 ml/kg for 2 hours then they will be randomized into : A-group (APRV group) & B-group (BiPAP group). which are described later in the 2 arms of the study.
Measurement tools :
The following data will be recorded :
- Demographic data ( Age , Sex , Weight and Height ).
- P/F ratio before inclusion.
- All patients then will be connected to Volumetric capnography which is included in the metabolic module on General Electric ventilator (Engstrom Carestation, GE Health care, USA). and physiological dead space will be recorded after 30 minutes and at the end of the 3 hours on each APRV & BiPAP modes .
- Peak air way pressure.
- Mean airway Pressure. They will be also recorded after
- Dynamic Compliance. 30 Minutes and at the end of the
- P/F ratio , PH and pCO2. 3 hours On APRV & BiPAP modes.
- Minute ventilation.
- Blood pressure , Heart rate and central venous pressure will be recorded before inclusion . then , they will be also recorded every 2 hours .
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Crossover
- 主要目的
- Supportive Care
- 盲法
- None
入排标准
- 年龄范围
- 18 Years 至 —（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •Adults above 18 years old.
- •Patients who are recently mechanically ventilated ( within 48 hours ).
- •Patients with P/F ratio less than 300.
排除标准
- •patients with COPD or pneumothorax.
- •Patients with acute lung injury.
- •patients with Emphysema and Emphysematous bullae .
- •patients with broncho-pleural fistula.
- •patients with severe hemodynamic instability (on IV Noradrenaline > 0.8 mic/kg/min).
- •patients with cardiomyopathy , and those with stenotic valvular diseases.
- •Patients with increased intracerebral pressure.
研究组 & 干预措施
APRV ventilation
They will start on APRV mode with high pressure (Phi) 20 cmH2O , low pressure(Plo) 5 cmH2O with I:E ratio ( Phi phase: Plo phase ratio ) 4:1 for 3 hours Then, they will return to the initial settings ( PCV ) for 2 hours . then, they will be switched into BiPAP mode with high pressure (Phi) 20 cmH2O , low pressure(Plo) 5 cmH2O with I:E ratio ( Phi phase: Plo phase ratio ) 1:1 for 3 hours. Then left for ventilation according to the preference of the physician in charge.
干预措施: APRV ventilation mode (Device)
BiPAP ventilation
They will start on BiPAP mode with high pressure (Phi) 20 cmH2O , low pressure(Plo) 5 cmH2O with I:E ratio ( Phi phase: Plo phase ratio ) 1:1 for 3 hours. Then, they will return to the initial settings ( PCV ) for 2 hours . then, they will be switched into APRV mode with high pressure (Phi) 20 cmH2O , low pressure(Plo) 5 cmH2O with I:E ratio ( Phi phase: Plo phase ratio ) 4:1 for 3 hours. Then left for ventilation according to the preference of the physician in charge.
干预措施: BIPAP ventilation moood (Device)
结局指标
主要结局
Physiological dead space
时间窗: after 30 min. on each mode ( APRV and BiPAP )
percentage of vd/vt ( dead space volume/ Tidal volume ) which is measured by volumetric capnography included in the metabolic module on General Electric ventilator (Engstrom Carestation, GE Health care, USA).
次要结局
- PCO2(after 30 min. and 3 hours on each mode ( APRV and BiPAP ).)
- Physiological dead space.(after 3 hours on each mode ( APRV and BiPAP ).)
- PO2/FiO2 ratio(after 30 min. and 3 hours on each mode ( APRV and BiPAP ).)
- Peak airway pressure(after 30 min. and 3 hours on each mode ( APRV and BiPAP ).)
- Mean airway pressure(after 30 min. and 3 hours on each mode ( APRV and BiPAP ).)
- Dynamic compliance(after 30 min. and 3 hours on each mode ( APRV and BiPAP ).)
- pH(after 30 min. and 3 hours on each mode ( APRV and BiPAP ).)
研究者
Ahmed Samir Awad Elkahwagy
Principal Investigator ,Dr. Ahmed Samir Elkahwagy
Kasr El Aini Hospital