Comparison of Pressure- and Volume-Controlled Ventilation in Laparoscopic Surgery: A Meta-analysis of Randomized Controlled Trial
Bibliographic record
Abstract
PURPOSE: Volume-controlled ventilation (VCV) has been the traditional mechanical ventilation mode in laparoscopic surgery. Pressure-controlled ventilation (PCV) has been used more frequently in recent years, especially for patients with complicated conditions; however, evidence on whether PCV is superior to VCV is still lacking. A meta-analysis was used to compare the effects of PCV and VCV on respiratory and hemodynamic parameters during laparoscopic surgery. METHODS: PubMed and Embase were each searched from their inception to December 2014 for randomized controlled trials comparing the effects of PCV and VCV on respiratory and hemodynamic parameters during laparoscopic surgery. Standard mean difference (SMD) with 95% confidence interval (CI) was calculated using a random effect model. Outcomes were assessed at three times: preoperative (T1), intraoperative (T2) and postoperative (T3). Respiratory mechanics (including peak airway pressure, plateau pressure, mean airway pressure, compliance, airway resistance, minute volume, end-tidal CO2 tension and tidal volume) and hemodynamic parameters (including heart rate and mean arterial pressure) were calculated. RESULTS: Eight randomized controlled trials with a total of 428 participants, 214 cases using PCV and 214 cases using VCV, were included in the meta-analysis. No significant differences were detected between the groups in terms of hemodynamic parameters. In contrast, with respiratory mechanics, PCV was slightly but significantly associated with lower peak airway pressure, higher compliance, lower airway resistance at T1, lower peak airway pressure, higher compliance, higher mean airway pressure at T2, lower peak airway pressure, lower mean airway pressure and higher end-tidal CO2 tension at T3. For the rest of respiratory parameters, there were no statistical differences between the groups. Subgroup analysis by morbidly obese, type of operations and quality of studies, showed similar results. CONCLUSIONS: Our meta-analysis suggests that hemodynamic parameters are similar in patients who underwent laparoscopic surgery with PCV and VCV, but patients who had PCV exhibited mildly better respiratory data.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.015 | 0.035 |
| Meta-epidemiology (narrow) | 0.003 | 0.001 |
| Meta-epidemiology (broad) | 0.024 | 0.046 |
| Bibliometrics | 0.004 | 0.005 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.004 | 0.002 |
| Open science | 0.002 | 0.001 |
| Research integrity | 0.003 | 0.003 |
| Insufficient payload (model declined to judge) | 0.004 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".