NCT06662799

Brief Summary

Postoperative pulmonary complications (PPCs) are common in patients after major abdominal surgery. It has been shown that 5-40% of patients occur PPCs after major surgery, and the mid to high PPC rate is observed after laparoscopic colorectal cancer surgery. PPCs are associated with poor clinical outcomes including prolonged hospital length of stay and increased morbidity and mortality. Mechanical ventilation during general anesthesia can lead to a redistribution of ventilation, increase the aereation in the ventral parts of the lung, whereas reduce ventilation in the dorsal parts of the lung compared with spontaneous breathing (SB) in the awake state in supine position. The reduction of ventilation of dorsal lung regions indicates the presence of dorsal atelectasis during mechanical ventilation after general anesthesia, which may be associated with PPCs. However, there is still no evidence to reveal the association between the reduction of dorsal ventilation and PPCs. Recently, electrical impedance tomography (EIT), which allows visualization of lung ventilation in real time, and assessment of regional lung ventilation. It is feasible to assess the change of ventral/dorsal lung ventilation during the surgery using EIT. To date, no study has investigated whether the change of ventral/dorsal lung ventilation revealed by EIT could be associated with PPCs. So, this prospective observational study aims to clarify whether patients developing postoperative pulmonary complications had higher reduction of dorsal lung ventilation during operation after general anesthesia as compared to patients not developing postoperative pulmonary complications. Ratio of dorsal ventilation during spontaneous respiration (T0) in the awake state as a reference, the proportion of dorsal ventilation after anesthesia induction and endotracheal intubation (T1), body position change and capnoperitoneum (T2), and at the end of surgery (T3) were analyzed. Thereafter, evaluating the change of dorsal ventilation in patients with PPCs and without PPCs at different time points. According to the method of sample size calculation published by Scaramuzzo G et al. (Anesthesiology. 2024 Oct 1;141(4):693-706.). A minimum sample size required for this study was calculated as following: using the difference of reduction of dorsal ventilation at the end of surgery between the patients with PPCs and non-PPCs as the primary outcome. Considering the data of our preliminary experiment showed that a reduction of dorsal lung ventilation at the end of surgery is 12 ± 6% and hypothesizing 30% of patients experiencing postoperative pulmonary complications and a relative clinically relevant increase in reduction of dorsal lung ventilation of 40% in those with postoperative pulmonary complications, we found that 83 patients were sufficient to evaluate differences between groups (effect size 0.8) with a power of 0.90 and an α error of 0.05. Considering a dropout of 10%, we found a minimum sample size of 92 patients.

Trial Health

87
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
92

participants targeted

Target at P50-P75 for all trials

Timeline
Completed

Started Jul 2024

Shorter than P25 for all trials

Geographic Reach
1 country

1 active site

Status
completed

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

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Study Timeline

Key milestones and dates

Study Start

First participant enrolled

July 1, 2024

Completed
3 months until next milestone

First Submitted

Initial submission to the registry

October 7, 2024

Completed
22 days until next milestone

First Posted

Study publicly available on registry

October 29, 2024

Completed
2 months until next milestone

Primary Completion

Last participant's last visit for primary outcome

December 15, 2024

Completed
10 days until next milestone

Study Completion

Last participant's last visit for all outcomes

December 25, 2024

Completed
Last Updated

January 3, 2025

Status Verified

December 1, 2024

Enrollment Period

6 months

First QC Date

October 7, 2024

Last Update Submit

December 31, 2024

Conditions

Outcome Measures

Primary Outcomes (1)

  • The difference of reduction of dorsal ventilation at the end of surgery between the patients with PPCs and non-PPCs

    1. EIT to monitor the regional ventilation of the patients at spontaneous breathing (SB) in the awake state in supine position (T0) and the end of surgery (T3). The reduction of the ratio of dorsal ventilation will be caculated between T3 and T0. 2. Follow-up the patients untill discharge from the hostiptal. Based on whether pulmonary complication occurs during 7 days after surgery, the participants will be divided into the patients with PPCs and the patients with non-PPCs. 3. The difference of reduction of dorsal ventilation at the end of surgery (T3) between the patients with PPCs and non-PPCs will be analyzed.

    1-7 days after surgery.

Secondary Outcomes (3)

  • The difference of reduction of dorsal ventilation at endotracheal intubation after general anesthesia induction between the patients with PPCs and non-PPCs

    1-7 days after surgery.

  • The difference of reduction of dorsal ventilation at pneumoperitoneum and body position change between the patients with PPCs and non-PPCs

    1-7 days after surgery.

  • The risk factors which are associated with PPCs

    1-7 days after surgery.

Other Outcomes (1)

  • The difference of hostpital stays between the patients with PPCs and non-PPC

    From the end of surgery to the discharge from hospital, an average of 2 weeks

Eligibility Criteria

Age18 Years+
Sexall
Healthy VolunteersNo
Age GroupsAdult (18-64), Older Adult (65+)
Sampling MethodNon-Probability Sample
Study Population

Patients undergoing laparoscopic colorectal cancer surgery

You may qualify if:

  • Age ≥18 years
  • ASA grade I-III
  • The patients who are planning to undergo laparoscopic colorectal cancer surgery

You may not qualify if:

  • Emergency surgery
  • Time of surgery less than 2 hours
  • Preoperatively present upper respiratory tract infection or acute pulmonary infection
  • Previous history of pulmonary surgery
  • Preoperative use of home ventilator
  • Inability to perform EIT monitoring
  • Declined to participate in this study

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

The first Affiliated Hospital, School of Medicine, Zhejiang University.

Hangzhou, Zhejiang, 310000, China

Location

Study Design

Study Type
observational
Observational Model
COHORT
Time Perspective
PROSPECTIVE
Target Duration
10 Days
Sponsor Type
OTHER
Responsible Party
PRINCIPAL INVESTIGATOR
PI Title
Director of the Anesthesiology Department

Study Record Dates

First Submitted

October 7, 2024

First Posted

October 29, 2024

Study Start

July 1, 2024

Primary Completion

December 15, 2024

Study Completion

December 25, 2024

Last Updated

January 3, 2025

Record last verified: 2024-12

Locations