HFLVV for Hypoxemia in Robot-assisted Cardiac Surgery
- Conditions
- Hypoxemia
- Interventions
- Procedure: Differential ventilation to the non-dependent lung
- Registration Number
- NCT04926649
- Lead Sponsor
- Daping Hospital and the Research Institute of Surgery of the Third Military Medical University
- Brief Summary
These robot-assisted cardiac surgeries usually require single-lung ventilation (SLV) to facilitate surgical exposure. SLV creates ventilation/perfusion mismatch and shunt (Qs:Qt) through the collapsed lung and leads to hypoxemia. Pulmonary gas exchange often deteriorates after cardiopulmonary bypass (CPB) because of ischemic tissue damage. In some cases, severe hypoxemia may require the cessation of surgical procedures and the initiation of double-lung ventilation to improve oxygenation. In this study, the investigator applied the continuous positive airway pressure (CPAP) or the high-frequency low-volume ventilation (HFLVV) to the non-dependent lung (differential ventilation) during the weaning from CPB. The investigator hypothesized that the differential ventilation would produce the least interference with the surgeon's exposure and better oxygenation. The investigators evaluate the airway pressure, shunt fraction, PaO2/FiO2, cerebral oximetry, surgical field condition and the length of stay in intensive care unit of patients underwent the robot-assisted cardiac surgery.
- Detailed Description
Not available
Recruitment & Eligibility
- Status
- UNKNOWN
- Sex
- All
- Target Recruitment
- 56
- scheduled for robot-assisted cardiac surgery with cardiopulmonary bypass
- age <18 or > 70 years
- PaO2/FiO2 ratio < 300 mmHg before anesthesia induction
- American Society of Anesthesiologist (ASA) Grade > 3
- Patients who were converted to conventional open-chest procedure
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- PARALLEL
- Arm && Interventions
Group Intervention Description Conventional ventilation group Differential ventilation to the non-dependent lung Conventional SLV and complementary with DLV when necessary. When SLV was initiated, the patient was ventilated with left lung. FiO2 of 1.0, tidal volume of 6ml/kg, respiratory rate of 16-24 bpm, PEEP of 5-10 cmH2O. The right lung was totally collapsed. If the SpO2 decreased lower than 90%, DLV was started and the operation was paused until the SpO2 increased to 100%. Then the operation was restarted. HFLVV group Differential ventilation to the non-dependent lung SLV of left lung and HFLVV of right lung, and complementary with DLV when necessary. When SLV was initiated, the patient was ventilated with left lung. FiO2 of 1.0, tidal volume of 6ml/kg, respiratory rate of 16-24 bpm, PEEP of 5-10 cmH2O. After the right lung was totally collapsed, HFLVV was started with tidal volume of 2ml/kg, respiratory rate of 60 bpm. If SpO2 decreased lower than 90%, DLV was started and the operation was paused until the SpO2 increased to 100%. Then the operation was restarted. CPAP group Differential ventilation to the non-dependent lung SLV of left lung and CPAP of right lung, and complementary with DLV when necessary. When SLV was initiated, the patient was ventilated with left lung. FiO2 of 1.0, tidal volume of 6ml/kg, respiratory rate of 16-24 bpm, PEEP of 5-10 cmH2O. After the right lung was totally collapsed, CPAP was started with the pressure less than 8 cmH2O. If SpO2 decreased lower than 90%, DLV was started and the operation was paused until the SpO2 increased to 100%. Then the operation was restarted.
- Primary Outcome Measures
Name Time Method Changes of PaO2/FiO2 ratio 5 min after induction of anesthesia during DLV, 5 min after SLV, 5 min after HFLVV, 5 min after CPB flow reduced to 1/3, 5min after CPB flow reduced to 2/3, 15min after resuming of DLV] PaO2/FiO2 ratio defined as the ratio of PaO2 to fractional inspired oxygen (FiO2 expressed as a fraction)
Changes of arterial PaO2 5 min after induction of anesthesia during DLV, 5 min after SLV, 5 min after HFLVV, 5 min after CPB flow reduced to 1/3, 5min after CPB flow reduced to 2/3, 15min after resuming of DLV] Arterial PaO2 (in mmHg) defined as a measurement of partial pressure of oxygen in arterial blood
- Secondary Outcome Measures
Name Time Method Changes of respiratory rates 5 min after induction of anesthesia during DLV, 5 min after SLV, 5 min after HFLVV, 5 min after CPB flow reduced to 1/3, 5min after CPB flow reduced to 2/3, 15min after resuming of DLV] Respiratory rates of both lungs in breath per minute
Changes of mean blood pressure 5 min after induction of anesthesia during DLV, 5 min after SLV, 5 min after HFLVV, 5 min after CPB flow reduced to 1/3, 5min after CPB flow reduced to 2/3, 15min after resuming of DLV] mean blood pressure in mmHg
Changes of venous pressure of jugular vein 5 min after induction of anesthesia during DLV, 5 min after SLV, 5 min after HFLVV, 5 min after CPB flow reduced to 1/3, 5min after CPB flow reduced to 2/3, 15min after resuming of DLV] Venous pressure of jugular vein in cmH2O
Changes of tidal volume 5 min after induction of anesthesia during DLV, 5 min after SLV, 5 min after HFLVV, 5 min after CPB flow reduced to 1/3, 5min after CPB flow reduced to 2/3, 15min after resuming of DLV] Tidal volume of both lungs in milliliter
Changes of the pulmonary shunt fraction 5 min after induction of anesthesia during DLV, 5 min after SLV, 5 min after HFLVV, 5 min after CPB flow reduced to 1/3, 5min after CPB flow reduced to 2/3, 15min after resuming of DLV] Qs/Qt = ((CcO2 - CaO2) / (CcO2 - CvO2)) \* 100
Changes of cardiac stroke volume variation 5 min after induction of anesthesia during DLV, 5 min after SLV, 5 min after HFLVV, 5 min after CPB flow reduced to 1/3, 5min after CPB flow reduced to 2/3, 15min after resuming of DLV] Cardiac stroke volume variation in percentages
Changes of blood oxygen saturation 5 min after induction of anesthesia during DLV, 5 min after SLV, 5 min after HFLVV, 5 min after CPB flow reduced to 1/3, 5min after CPB flow reduced to 2/3, 15min after resuming of DLV] Blood oxygen saturation of both upper and lower extremities in percentages
Changes of regional cerebral oxygen saturation 5 min after induction of anesthesia during DLV, 5 min after SLV, 5 min after HFLVV, 5 min after CPB flow reduced to 1/3, 5min after CPB flow reduced to 2/3, 15min after resuming of DLV] regional cerebral oxygen saturation in percentages
Changes of the surgical field 5 min after induction of anesthesia during DLV, 5 min after SLV, 5 min after HFLVV, 5 min after CPB flow reduced to 1/3, 5min after CPB flow reduced to 2/3, 15min after resuming of DLV] The surgeon's evaluation of the surgical field, graded from 0 (no interference) to 3 (maximal interference)
Changes of Heart rate 5 min after induction of anesthesia during DLV, 5 min after SLV, 5 min after HFLVV, 5 min after CPB flow reduced to 1/3, 5min after CPB flow reduced to 2/3, 15min after resuming of DLV Heart rate in beat per minute
Changes of airway pressure 5 min after induction of anesthesia during DLV, 5 min after SLV, 5 min after HFLVV, 5 min after CPB flow reduced to 1/3, 5min after CPB flow reduced to 2/3, 15min after resuming of DLV] Airway pressure of both lungs in mmHg
Changes of end-tidal carbon dioxide tension 5 min after induction of anesthesia during DLV, 5 min after SLV, 5 min after HFLVV, 5 min after CPB flow reduced to 1/3, 5min after CPB flow reduced to 2/3, 15min after resuming of DLV] End-tidal carbon dioxide tension in mmHg
Trial Locations
- Locations (1)
Daping Hospital, Army Medical University
🇨🇳Chongqing, Chongqing, China