Postoperative Atelectasis, Pulmonary Atelectasis
Conditions
Keywords
Fresh Gas Flow, Lung Ultrasound Score, Pulmonary Complications
Brief summary
This prospective randomized clinical trial aims to evaluate the effects of different fresh gas flow rates on postoperative pulmonary aeration using lung ultrasonography in patients undergoing elective laparoscopic cholecystectomy. Patients will be randomly assigned to receive either low-flow anesthesia (0.5 L/min) or high-flow anesthesia (4 L/min) during maintenance of general anesthesia. The primary objective is to compare postoperative lung ultrasound scores and the incidence of atelectasis between the two groups.
Detailed description
Pulmonary atelectasis is one of the most common postoperative pulmonary complications following general anesthesia. Fresh gas flow is an important component of inhalational anesthesia and may influence airway humidity, gas exchange, respiratory mechanics, and pulmonary physiology. Although low-flow anesthesia has recognized economic, environmental, and physiological advantages, the effect of different fresh gas flow rates on postoperative lung aeration has not been adequately investigated. This prospective, randomized, parallel-group clinical trial will be conducted at Adıyaman University Training and Research Hospital. Adult patients scheduled for elective laparoscopic cholecystectomy under general anesthesia will be randomly allocated to either a low-flow group (0.5 L/min) or a high-flow group (4 L/min) after an initial fresh gas flow of 4 L/min for 8 minutes following endotracheal intubation. Standardized anesthesia management will be applied to all participants. Postoperative lung ultrasonography will be performed 30 minutes after extubation in the post-anesthesia care unit. Lung Ultrasound Score (LUS) and the incidence of postoperative atelectasis will be compared between the study groups. The findings are expected to provide evidence regarding the effects of different fresh gas flow strategies on postoperative pulmonary outcomes and may contribute to optimizing intraoperative anesthesia management.
Interventions
PROCEDURELow Fresh Gas Flow (0.5 L/min)
General anesthesia will be maintained using a fresh gas flow rate of 0.5 L/min after an initial fresh gas flow of 4 L/min for 8 minutes following endotracheal intubation.
PROCEDUREHigh Fresh Gas Flow (4 L/min)
General anesthesia will be maintained using a fresh gas flow rate of 4 L/min after an initial fresh gas flow of 4 L/min for 8 minutes following endotracheal intubation.
Sponsors
Adiyaman University
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
DOUBLE (Subject, Outcomes Assessor)
Intervention model description
Participants will be randomly assigned in a 1:1 ratio to either the low fresh gas flow group (0.5 L/min) or the high fresh gas flow group (4 L/min). Each participant will receive only one intervention throughout the study, and postoperative lung ultrasound findings will be compared between the two parallel groups.
Eligibility
Sex/Gender
ALL
Age
18 Years to 65 Years
Healthy volunteers
No
Inclusion criteria
* Adults aged 18 years or older. * American Society of Anesthesiologists (ASA) physical status I-II. * Scheduled for elective laparoscopic cholecystectomy under general anesthesia. * Able and willing to provide written informed consent.
Exclusion criteria
* Refusal to participate in the study. * History of chronic respiratory disease, including severe asthma, chronic obstructive pulmonary disease (COPD), or bronchiolitis. * History of alcohol or substance abuse. * Intraoperative airway or respiratory complications during endotracheal intubation or surgery. * Life-threatening postoperative complications. * Patients with ASA physical status III or higher.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Postoperative Lung Ultrasound Score | 30 minutes after extubation | Lung ultrasonography will be performed 30 minutes after extubation. Both lungs will be divided into 12 regions, with 6 regions assessed in each lung. Each region will be scored from 0 to 3: 0 indicates normal aeration with A-lines or fewer than three B-lines; 1 indicates at least three well-spaced B-lines; 2 indicates coalescent B-lines; and 3 indicates lung consolidation. The scores from all regions will be summed, resulting in a total score ranging from 0 to 36. Higher scores indicate greater loss of lung aeration. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Incidence of postoperative atelectasis | 30 minutes after extubation | Atelectasis will be defined as a consolidation score ≥2 in any lung region assessed by lung ultrasonography |
| Peripheral oxygen saturation (SpO₂) | During surgery | — |
| Mean arterial pressure | During surgery | — |
| Heart rate | During surgery | — |
| Peak airway pressure | Throughout the intraoperative period | Peak airway pressure will be recorded during general anesthesia and compared between the low and high fresh gas flow groups. |
Countries
Turkey (Türkiye)
Contacts
CONTACTMEHMET DURAN, MD, Associate Professor
Outcome results
None listed