One Lung Ventillation (OLV), Positive End Expiratory Pressure (PEEP), Two Lung Ventillation (TLV), Zero End-expiratory Pressure (ZEEP)
Conditions
Brief summary
One method for treating intraoperative hypoxia during one-lung ventilation (OLV) is application of PEEP to the dependent lung. However, only a minority of patients benefit from this maneuver. The effect of applied PEEP on oxygenation depends on the relation between the total end-expiratory pressure and the lower inflexion point (LIP) of pressure-volume curve (1). LIP during OLV can be determined with super-syringe technique, but is too complicated for routine operating room use. An alternative is the constant-flow method which is easy and widely used in intensive care settings (2). The investigators goal was to confirm that the constant-flow method as applied by an intensive care ventilator works during OLV. Methods: After IRB approval and written, informed consent, data were obtained from 20 patients during OLV for thoracic surgery who were ventilated with an AVEA (VIASYS Healthcare) critical-care ventilator. During two-lung ventilation (TLV) and OLV 8 ml•kg-1 tidal volume was used. During OLV, ventilation periods of ten minutes, with and without 5 cmH2O PEEP were alternated. During each period, the investigators recorded arterial blood partial pressures, respiratory and hemodynamic values, intrinsic PEEP (PEEPi), and LIP. PEEPi and LIP were determined using the automatic mode of the ventilator; specifically, LIP was determined with a continuous flow of 3L/minute.
Interventions
OTHERtwo lung ventilation (TLV)
During two-lung ventilation (TLV) and OLV 8 ml•kg-1 tidal volume was used.
OTHERone lung ventilation (OLV) without PEEP
During OLV, ventilation periods of ten minutes, with and without 5 cmH2O positive end-expiratory pressure (PEEP) were alternated.
OTHEROne lung ventilation (OLV) with positive end-expiratory pressure (PEEP)
During OLV, ventilation periods of ten minutes, with and without 5 cmH2O positive end-expiratory pressure (PEEP) were alternated
Sponsors
The Cleveland Clinic
Study design
Allocation
NON_RANDOMIZED
Intervention model
SINGLE_GROUP
Primary purpose
OTHER
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* thoracic surgery lung ventillation
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| intrinsic positive end-expiratory pressure (PEEP) during ventillation | 10 minutes | constant-flow method useful for determination of intrinsic positive end-expiratory pressure (PEEPi) during OLV |
| lower inflexion point (LIP) of P-V curve during one lung ventillation (OLV) | 10 minutes | constant-low method useful for determination of lower inflexion point (LIP) of P-V curve during one lung ventillation (OLV). |
| net change of Lower Inflexion Point (LIP)- intrinsic positive end-expiratory pressure (PEEPi) ditstance with PEEP | 10 minutes | Relationship between the net change of lower inflexion point (LIP)- positive end-expiratory pressure (PEEPi) ditstance with and without positive end-expiratory pressure (PEEP) and change of PaO2 is useful during OLV for determination of patients reaction for application extternal positive end-expiratory pressure (PEEP) |
| net change of lower inflexion point (LIP)-PEEPi ditstance without PEEP | 10 minutes | Relationship between the net change of lower inflexion point (LIP)-intrinsic positive end-expiratory pressure (PEEPi) ditstance with and without positive end-expiratory pressure (PEEP) and change of PaO2 is useful during one lung ventillation (OLV) for determination of patients reaction for application external positive end-expiratory pressure (PEEP). |
Outcome results
None listed