Clinical trial NCT06256900: Flow Controlled Ventilation in Robot-assisted Laparoscopic Surgery
Official title: Flow Controlled Ventilation to Improve Postoperative Pulmonary Outcome After Robot-assisted Laparoscopic Surgery - a Prospective, Randomised, Single-blinded, Controlled and Single-centre Investigation
Study type: INTERVENTIONAL
Overall status: WITHDRAWN
Phase: NA
Conditions: Mechanical Ventilation Complication
Postoperative Pulmonary Atelectasis
Keywords: Flow-controlled ventilation
Postoperative pulmonary complications
electrical impedance tomography
Lead sponsor: Cantonal Hospital of St. Gallen
Sponsor class: OTHER
First posted: 2024-02-13
Enrollment: 0
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Intervention model description: Randomized, controlled, single-center study
Primary purpose: TREATMENT

Brief summary: The optimization of ventilation is especially important during general anaesthesia, when active, physiologic respiration suspends and is replaced by non-physiologic mechanical positive pressure ventilation. Aiming at preserving compliance of lung tissue to guarantee an effective gas exchange is to avoid an excessive pressure application, especially in extreme positioning of the patient (Trendelenburg positioning) and/or pneumoperitoneum resulting in additional non-physiologic intrathoracic pressure. Perioperative lung protection strategies have steadily improved in recent years to reduce complications from mechanical ventilation, but postoperative pulmonary complications remain a risk factor for increased morbidity and mortality.

Detailed description: Mechanical ventilation is crucial during general anesthesia, with ongoing efforts to refine strategies for optimal respiratory support. Important articles on perioperative ventilation explored key aspects, including PEEP application, tidal volume effects, PPC after major surgeries, and perioperative oxygen titration to mitigate oxidative stress. PEEP plays a pivotal role in enhancing oxygenation and preventing atelectasis during mechanical ventilation. Landmark studies by the ARDS Network highlight the importance of customizing PEEP application. This tailored approach not only improves respiratory mechanics but also reduces the risk of barotrauma, underscoring the crucial impact of personalized PEEP strategies. Concurrently, adopting a lung-protective strategy with low tidal volumes, has proven effective in mitigating ventilator-induced lung injury. These strategies aim to strike a balance between optimal oxygenation and minimizing potential complications associated with mechanical ventilation. Despite advancements in perioperative care, PPC remain a concern, particularly following major surgical procedures. Recent investigations emphasize the multifactorial nature of these complications. Early identification of risk factors and meticulous monitoring are crucial to reducing the incidence of complications such as atelectasis, pneumonia, and respiratory insufficiency. Understanding the interplay between mechanical ventilation strategies and postoperative outcomes is essential for improving patient recovery. The pursuit of optimal oxygenation must be balanced against the potential for oxygen toxicity and oxidative stress. Available studies shed light on the delicate equilibrium required in maintaining adequate oxygen delivery while avoiding the detrimental effects of hyperoxia. Clinicians must consider individual patient factors and tailor oxygen therapy to prevent oxidative stress, which can contribute to tissue damage and compromise overall patient well-being. FCV is a new ventilation strategy designed to minimize the mechanical effects of perioperative ventilation on lung tissue. Compared to traditionally employed ventilation strategies, gas flow is controlled during both inspiration and expiration in FCV. In particular, the almost linear pressure drop during the expiratory phase of FCV has been shown in various ex vivo/experimental and clinical studies to improve gas exchange and the proportion of ventilated lung tissue.

Ongoing advancements in mechanical ventilation shape anesthesia practices with a focus on evidence-based approaches for patient safety. Building on prior findings, this study explores the benefits of the novel ventilation approach, FCV, aiming to reduce dissipative energy and alveolar stress. The investigators hypothesize positive impacts on perioperative ventilation, vital parameters, and a decreased incidence of PPC, contributing to overall postoperative morbidity and mortality reduction.

Eligibility criteria: Inclusion Criteria:

* Patient undergoing elective robot-assisted laparoscopic surgery (either abdominal, urologic or gynecologic surgery) with a duration of expected ventilation of ≥ 90 minutes
* Male or female aged ≥ 18 years
* ASA Physical Status Classification System score I - III
* Must be willing and able to give written informed consent to participate in the study and agree to comply with the study protocol prior to initiation of any study-mandated procedure and study intervention

Exclusion Criteria:

* Patient with weight \< 40 kg ideal body weight
* ASA Physical Status Classification System score IV - VI
* Previous enrolment into the current study
* Enrolment of study investigator, his/her family members, employees and other dependent persons
* If female and of childbearing potential: known pregnancy or a positive urine pregnancy test (confirmed by a positive serum pregnancy test), or lactating

Primary outcomes:
measure: Differences in the number of patients developing postoperative pulmonary complications
timeFrame: to postoperative day 5/discharge
Secondary outcomes:
measure: Differences in Clara-Cell 16 serum concentrations
timeFrame: periprocedural
measure: Differences in area under the curve of postoperative modified Horovitz index
timeFrame: first hour after surgery
measure: Differences in end-tidal to capillary/arterial CO2 gradient
timeFrame: periprocedural
measure: Differences in minimal required intraoperative FiO2 concentration
timeFrame: periprocedural
measure: Differences in parameters derived from the electrical impedance tomography
timeFrame: periprocedural
measure: Differences in perioperative ventilation/oxygenation parameters
timeFrame: periprocedural
Other outcomes:
measure: Number of patients developing events defined as safety events
timeFrame: periprocedural
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