Comparison of Volume-controlled and Pressure-controlled Ventilation in Clasp-knife Position
Condition: Mechanical Ventilation; General Anesthesia; Urological Surgery; Robotic Surgery
Study type: Interventional

Summary: 
      Carbon dioxide (CO2) pneumoperitoneum and clasp-knife positioning are commonly used to
      improve surgical access during robot-assisted laparoscopic urological surgery. However, these
      methods are sometimes associated with several unwanted cardiopulmonary effects such as
      increased mean arterial pressure, decreased pulmonary compliance and functional residual
      capacity, increased peak inspiratory pressure, and respiratory acidosis in association with
      hypercarbia. Volume-controlled ventilation (VCV) is the most commonly used method of
      ventilation during general anesthesia. It provides fixed minute ventilation and pulmonary
      resistance, which affect airway pressure. In pressure-controlled ventilation (PCV), constant
      inspiratory airway pressure can be achieved by decelerating the flow. However, minute
      ventilation is not fixed . CO2 pneumoperitoneum in the clasp-knife positioning can influence
      hemodynamic variables, including blood pressure, heart rate, and cardiac output. This is
      because changes in airway pressure affect intrathoracic pressure and the function of the
      heart itself. In this randomized study, we investigated the effects of VCV and PCV on peak
      inspiratory pressure during robot-assisted laparoscopic urological surgery involving CO2
      pneumoperitoneum in the clasp-knife position.
    

Detailed description: 
      After careful screening, 60 patients were enrolled in the trial. The investigators monitored
      patients' breathing, circulation and carbon metabolism by measuring arterial gas, cardiac
      output monitoring, respiratory parameters and circulation parameters at different times in
      both groups of patients.
    

Intervention name(s): record Hemodynamic variables, respiratory variables and arterial blood gas at specific times
Intervention type(s): Behavioral
Intervention description(s): Hemodynamic variables, respiratory variables and arterial blood gas were measured and recorded 15 minutes after induction of anesthesia (T1), 15 minutes after establishment of a folding knife position (T2), 30 and 60 minutes after CO2 pneumoconiosis (T3 and T4), and 15 minutes after pneumoconiosis (T5). Hemodynamic variables measured included mean arterial pressure , heart rate , cardiac output, cardiac index, stroke volume index and stroke volume variation. Breathing variables include tidal volume, minute ventilation , respiratory rate , airway frontal pressure , mean airway pressure , plateaus airway pressure , peripheral oxygen saturation , oxygen saturation , and oxygen response . Arterial blood gas variables include pH value, arterial carbon dioxide, arterial oxygen pressure , alkali surplus , alveolar oxygen pressure , and bicarbonate of soda ion concentration .
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Investigator)
Primary purpose: Treatment
Keywords: Mechanical ventilation; robot-assisted surgery