Physiological Dead Space Measured by Volumetric Capnography in BiPAP and APRV .
Study Details
Study Description
Brief Summary
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
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Physiological dead space after 3 hours.
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PO2/FiO2 ratio.
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Peak airway and Mean airway pressures.
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PCO2 and PH.
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Dynamic compliance.
| Condition or Disease | Intervention/Treatment | Phase |
|---|---|---|
|
N/A |
Detailed Description
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 :
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Demographic data ( Age , Sex , Weight and Height ).
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P/F ratio before inclusion.
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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 .
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Peak air way pressure.
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Mean airway Pressure. They will be also recorded after
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Dynamic Compliance. 30 Minutes and at the end of the
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P/F ratio , PH and pCO2. 3 hours On APRV & BiPAP modes.
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Minute ventilation.
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Blood pressure , Heart rate and central venous pressure will be recorded before inclusion . then , they will be also recorded every 2 hours .
Study Design
Arms and Interventions
| Arm | Intervention/Treatment |
|---|---|
| Active Comparator: 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. |
Device: APRV ventilation mode
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
|
| Active Comparator: 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. |
Device: BIPAP ventilation moood
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
|
Outcome Measures
Primary Outcome Measures
- Physiological dead space [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).
Secondary Outcome Measures
- Physiological dead space. [after 3 hours 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).
- PO2/FiO2 ratio [after 30 min. and 3 hours on each mode ( APRV and BiPAP ).]
PO2 from ABG / FiO2 set on the ventilator
- Peak airway pressure [after 30 min. and 3 hours on each mode ( APRV and BiPAP ).]
measured by the ventilator in cmH2O.
- Mean airway pressure [after 30 min. and 3 hours on each mode ( APRV and BiPAP ).]
measured by the ventilator in cmH2O.
- Dynamic compliance [after 30 min. and 3 hours on each mode ( APRV and BiPAP ).]
measured by the ventilator ml/cmH2O
- PCO2 [after 30 min. and 3 hours on each mode ( APRV and BiPAP ).]
from ABG
- pH [after 30 min. and 3 hours on each mode ( APRV and BiPAP ).]
from ABG
Eligibility Criteria
Criteria
Inclusion Criteria:
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Adults above 18 years old.
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Patients who are recently mechanically ventilated ( within 48 hours ).
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Patients with P/F ratio less than 300.
Exclusion Criteria:
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patients with COPD or pneumothorax.
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Patients with acute lung injury.
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patients with Emphysema and Emphysematous bullae .
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patients with broncho-pleural fistula.
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patients with severe hemodynamic instability (on IV Noradrenaline > 0.8 mic/kg/min).
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patients with cardiomyopathy , and those with stenotic valvular diseases.
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Patients with increased intracerebral pressure.
Contacts and Locations
Locations
| Site | City | State | Country | Postal Code | |
|---|---|---|---|---|---|
| 1 | Department of Anesthesia , intensive care and pain management -faculty of medicine Cairo Uni.- kasr Alainy Hospitals. | Cairo | Egypt |
Sponsors and Collaborators
- Kasr El Aini Hospital
Investigators
- Study Director: Ahmed Elkahwagy, Department of Anesthesia , intensive care and pain management at kasr Alainy hospitals -faculty of medicine - Cairo Uni. - Egypt
Study Documents (Full-Text)
None provided.More Information
Additional Information:
Publications
- Anderson CT, Breen PH. Carbon dioxide kinetics and capnography during critical care. Crit Care. 2000;4(4):207-15. Epub 2000 Jul 12. Review.
- Baum M, Benzer H, Putensen C, Koller W, Putz G. [Biphasic positive airway pressure (BIPAP)--a new form of augmented ventilation]. Anaesthesist. 1989 Sep;38(9):452-8. German.
- Haitsma JJ, Lachmann RA, Lachmann B. Lung protective ventilation in ARDS: role of mediators, PEEP and surfactant. Monaldi Arch Chest Dis. 2003 Apr-Jun;59(2):108-18. Review.
- Hörmann C, Baum M, Putensen C, Mutz NJ, Benzer H. Biphasic positive airway pressure (BIPAP)--a new mode of ventilatory support. Eur J Anaesthesiol. 1994 Jan;11(1):37-42. Review.
- Verscheure S, Massion PB, Verschuren F, Damas P, Magder S. Volumetric capnography: lessons from the past and current clinical applications. Crit Care. 2016 Jun 23;20(1):184. doi: 10.1186/s13054-016-1377-3. Review.
- N-44-2017