Driving Pressure in Laparoscopic Surgery (DPPVL)

Capital Medical University

Status: Completed

Conditions: Laparoscopy

Treatments: Procedure: PEEP

Study type: Interventional

Funder types: Other

Identifiers

NCT04374162

DP-Laparoscopy

Details and patient eligibility

About

The effect of driving pressure (DP)-guided positive end expiratory pressure (PEEP) on early postoperative pulmonary ventilation is to be determined for patients undergoing laparoscopic surgery. Patients are recruited to receive volume controlled ventilation with either a fixed PEEP (5cmH2O) or DP titrated PEEP. Early postoperative regional distribution of lung ventilation, expressed as center of ventilation (COV) is evaluated by electrical impedance tomography (EIT), a noninvasive, radiation free modality. Perioperative ventilatory parameters, arterial oxygenation index (PaO2/FiO2) , serum indicators and postoperative pulmonary complications are secondary outcome variables.

Full description

After screened for preoperative risk factors, 48 patients undergoing elective laparoscopic surgery and planned to be extubated in the operating room are randomly assigned to two groups: (1) PEEP = 5cmH2O; (2) driving pressure (DP)-guided PEEP. The ventilation protocol consists of volume-controlled mechanical ventilation (Datex Ohmeda S/5 Advance; General Electric Company Healthcare, Helsinki, Finland) at a tidal volume (VT) of 8 ml/kg predicted body weight (PBW), fresh gas of 2 litre /min, inspiratory to expiratory ratio of 1:2, and a respiratory rate adjusted to normocapnia (arterial carbon dioxide partial pressure between 35 and 45 mmHg). For group 2, trial for the lowest DP was started 10 min after pneumoperitoneum and position adjustment by increasing PEEP from 5 to 15 cm H2O incrementally. DP was calculated as "plateau pressure - PEEP". Each PEEP level was maintained for 10 respiratory cycles, with DP in the last cycle recorded. Then the PEEP level producing the lowest DP was identified and maintained intraoperatively. A plateau pressure of no more than 30 cmH2O is targeted in each group.

Early postoperative distribution of regional ventilation as COV (center of ventilation) is the primary endpoint evaluated by EIT (electrical impedance tomography), which was performed by a trained technician who is blinded to randomization. Arterial blood gas is tested, with inflammatory and oxidative mediators from venous sample. Postoperative pulmonary complications within 3 days are also recorded.

Enrollment: 57 patients

Sex: All

Ages: 18 to 80 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Informed consent has been obtained
• Elective laparoscopic surgery with Trendelenburg position
• Expected ventilation duration > 2 hours
• Scheduled to be extubated in the operation

Exclusion criteria

• Mechanical ventilation of > 1 hour within the last 2 weeks before surgery
• Body mass index ≥ 35 kg/m2
• Acute respiratory failure (pneumonia, acute lung injury or acute respiratory distress syndrome)
• Emergency surgery
• Severe cardiac disease
• Progressive neuromuscular illness
• Pregnancy
• Refusal to participate
• Contradicted to EIT scan

Trial design

Primary purpose: Prevention

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Double Blind

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57 participants in 2 patient groups, including a placebo group

Conventional PEEP

Placebo Comparator group

Description:

PEEP = 5 cmH2O

Treatment:

Procedure: PEEP

Driving pressure (DP) guided-PEEP

Experimental group

Description:

DP is calculated as "plateau pressure - PEEP". 10 min after pneumoperitoneum， PEEP is increased from 5 to 15 cm H2O incrementally. Each PEEP level is maintained for 10 respiratory cycles, with DP in the last cycle recorded. Then the PEEP level producing the lowest DP will be identified and maintained intraoperatively.

Treatment:

Procedure: PEEP