An Exploratory Study on the Impact of Prolonged Postoperative Endotracheal Extubation Time on Postoperative Complications in Gastric Cancer Patients With Severe Obstructive Sleep Apnea
Conditions: Obstructive Sleep Apnea, Gastric Cancer (GC)
Sponsor: Qilu Hospital of Shandong University

Study Documents
Cover Page
Official Title of the study: An Exploratory Study on the Impact of Prolonged
Postoperative Endotracheal Extubation Time on Postoperative Complications in
Gastric Cancer Patients with Severe Obstructive Sleep Apnea
NCT number: NCT ID not yet assigned
Date of the document: 2026.1.15

Official Title of the study: An Exploratory Study on the Impact of Prolonged
Postoperative Endotracheal Extubation Time on Postoperative Complications in
Gastric Cancer Patients with Severe Obstructive Sleep Apnea
NCT number: NCT ID not yet assigned Unique Protocol Id：KYLL-202110-034-2
Date of the document: 2026.1.15
Clinical Study Protocol
Project Title: An Exploratory Study on the Impact of Prolonged Postoperative
Endotracheal Extubation Time on Postoperative Complications in Gastric Cancer
Patients with Severe Obstructive Sleep Apnea
Research Unit: <u>Department of General Surgery, Qilu Hospital of Shandong
University</u>
Principal Investigator: <u>Yu Wenbin</u>
Sponsor: <u>Qilu Hospital of Shandong University</u>
Study Abstract
Item
Content
Project Title
An Exploratory Study on the Impact of Prolonged
Postoperative Endotracheal Extubation Time on
Postoperative Complications in Gastric Cancer
Patients with Severe Obstructive Sleep Apnea
Study Objective
To investigate the impact of prolonging the time to
postoperative endotracheal extubation on the
incidence of postoperative complications in gastric
cancer patients with severe obstructive sleep apnea.
Research
Hypothesis
Prolonging the time to endotracheal extubation in
gastric cancer patients with severe obstructive sleep
apnea can reduce the incidence of postoperative
complications.
Study Design
□Case-Control Study ☑Cohort Study □

Item
Content
Cross-Sectional Study
□Case Report / Case Series
Study Subjects
Inclusion Criteria:
1. Patients preoperatively diagnosed with resectable
gastric cancer.
2. Patients without distant organ metastasis.
3. Patients with preoperative OCST or PSG results
showing AHI >30 events/hour and SaO₂ <80%.
4. Patients with cardiopulmonary function deemed
suitable for surgery.
5. Patients aged 18-85 years.
6. Patients who voluntarily joined this study and
provided written informed consent.
Exclusion Criteria:
1. Patients with a history of or concurrent other
malignant tumors.
2. Patients who underwent palliative resection.
3. Subjects who experienced acute cardiovascular or
cerebrovascular events (e.g., acute cerebral
infarction, acute coronary syndrome) within the past
3 months, or whose cardiovascular clinical
symptoms/diseases are not well-controlled.
4. Patients with a history of psychotropic drug abuse
that cannot be abstained, or those with psychiatric
disorders.
5. Patients with concomitant diseases that, in the
investigator’s judgment, seriously endanger the
patient’s safety or affect the completion of the
study.
Diagnostic
Criteria
Meet either (A + B) or C below.
A: Presence of at least 1 of the following: (1) Patient
complaints of sleepiness, non-restorative sleep,
fatigue, or insomnia; (2) Waking from sleep due to
choking or gasping; (3) Bed partner or other observer
reports of habitual snoring, breathing interruptions,
or both during sleep; (4) Diagnosed hypertension, mood
disorder, cognitive dysfunction, coronary artery
disease, cerebrovascular disease, congestive heart
failure, atrial fibrillation, or type 2 diabetes.
B: PSG or OCST confirms ≥5 respiratory events/hour
during monitoring, including obstructive apneas,

Item
Content
mixed apneas, hypopneas, and respiratory
effort-related arousals (RERAs).
C: PSG or OCST confirms ≥15 respiratory events/hour
during monitoring, including obstructive apneas,
mixed apneas, hypopneas, and RERAs.
Sample Size &
Justification
The incidence of postoperative complications in
gastric cancer patients with severe sleep apnea is the
primary endpoint of this study. Based on previous
large-scale literature reports, the incidence of
perioperative cardiovascular complications in
patients with severe sleep apnea undergoing
non-cardiac surgery is 15% higher than in the normal
population [8]. Using a power of 90% and a significance
level of 5%, sample size estimation was performed using
PASS, version 11 (NCSS, LLC). We need to recruit 93
patients per group. Accounting for loss to follow-up,
dropouts, and other factors, we plan to include at
least 120 patients per group.
Primary Exposure
Factor
Time to endotracheal extubation
Outcome Variables Incidence of short-term postoperative complications,
graded using the Clavien-Dindo classification.
Follow-up Plan
(For Cohort
Studies)
Routine follow-up examinations at 1, 3, 6, 9, and 12
months postoperatively. Collect routine follow-up
indicators and assess the occurrence of postoperative
complications.
Sample Collection ☑No □Yes
Brief description of tissue type and quantity: N/A
Non-Medical
Purpose
Examinations
☑No □Yes
e.g., unnecessary CT scans, contrast studies, lab
tests, etc.: N/A
Statistical
Methods
Chi-square test or Fisher's exact test will be used to
compare categorical variables. Continuous variables
will be expressed as median and IQR if non-normally
distributed and analyzed using the Mann-Whitney U
test, or as mean (SD) if normally distributed and
analyzed using the t-test.
Study Risk
Self-Assessment
□High-Risk Study □Medium-Risk Study ☑Low-Risk
Study
Brief explanation: This is an observational study.

Confidentiality Statement:
The information contained in this study protocol is provided
solely to the investigators of this project, the clinical
research
management
committee,
and
relevant
regulatory
bodies for review. Disclosing any information to third
parties unrelated to this study is strictly prohibited
without the approval of the Principal Investigator.
1. Research Background (State the rationale and significance of this study based on
current domestic and international research)
As one of the most common malignant tumors worldwide, gastric cancer ranks fifth
in global cancer incidence and fourth in cancer mortality [1]. Current treatment for
gastric cancer is comprehensive, primarily based on surgical treatment, with standard
radical gastrectomy being the main procedure [2]. This process is complex,
technically demanding, and carries relatively high surgical risks. Obstructive Sleep
Apnea (OSA) is a sleep-related breathing disorder characterized by periodic partial or
complete upper airway obstruction during sleep, manifesting as apneas and
hypopneas [3]. Preliminary statistics indicate the overall prevalence of OSA among
adults in China is 3.93% [4], yet the clinical diagnosis rate remains low. OSA is widely
recognized as an independent risk factor for hypertension and metabolic syndrome
[5, 6]. Reported prevalence of OSA among surgical patients is approximately 7%-10%,
but can reach 68%-70% in high-risk populations (bariatric surgery or other major
non-cardiac surgery). These patients have significantly increased perioperative
complications and mortality [7, 8], especially severe sleep apnea. One cohort study
reported the incidence of cardiovascular complications within 30 days after surgery
in patients with severe sleep apnea was as high as 30.1% [8]. General anesthesia,
sedatives, and postoperative analgesics are potent respiratory depressants; they can
relax the upper airway dilator muscles and impair the ventilatory response to
hypoxemia and hypercapnia. These effects exacerbate OSA. Concurrently, the
hypoxemia caused by OSA can increase the incidence of postoperative complications
in gastric cancer patients and may predispose them to postoperative cardiovascular
complications [9]. Therefore, for gastric cancer patients with severe sleep apnea,
strategies to reduce postoperative complications and adverse events are particularly
important.
2. Research Question & Objectives (Elucidate the scientific question and research
objectives)
To investigate the impact of prolonging the time to postoperative endotracheal
extubation on the incidence of postoperative complications in gastric cancer patients
with severe obstructive sleep apnea.
3. Research Methods (This section should be elaborated in detail)

Study Design
This is a single-center, prospective cohort study. Starting June 2025, the study plans
to enroll patients undergoing radical gastrectomy for gastric cancer in the
Department of General Surgery of our hospital who also have severe obstructive
sleep apnea. Based on the anesthesiologist's assessment during the perioperative
period regarding sufficient metabolism of anesthetic agents and full patient
awakening, patients will be divided into two groups regarding whether extubation
time is prolonged (by 1-2 days): Exposure Group: Prolonged extubation time group;
Non-Exposure Group: Non-prolonged extubation time group (extubation on the day
of surgery group). Clinical data, intraoperative details, postoperative pathology,
lymph node status, and postoperative complications will be recorded for all patients.
Study Site and Subjects (Source, Inclusion, and Exclusion Criteria)
All patients in this study will be inpatients from the Department of Gastrointestinal
Surgery, Qilu Hospital.
Inclusion Criteria:
Patients preoperatively diagnosed with resectable gastric cancer.
Patients without distant organ metastasis.
Patients with preoperative OCST or PSG results showing AHI >30 events/hour and
SaO₂ <80%.
Patients with cardiopulmonary function deemed suitable for surgery.
Patients aged 18-85 years.
Patients who voluntarily joined this study and provided written informed consent.
Exclusion Criteria:
Patients with a history of or concurrent other malignant tumors.
Patients who underwent palliative resection.
Subjects who experienced acute cardiovascular or cerebrovascular events (e.g., acute
cerebral infarction, acute coronary syndrome) within the past 3 months, or whose
cardiovascular clinical symptoms/diseases are not well-controlled.
Patients with a history of psychotropic drug abuse that cannot be abstained, or those
with psychiatric disorders.
Patients with concomitant diseases that, in the investigator’s judgment, seriously
endanger the patient’s safety or affect the completion of the study.

Study Variables (Factors) and Measurement
Study Variable: Whether endotracheal extubation time is prolonged.
Study Outcomes
Incidence of short-term postoperative complications, graded using the Clavien-Dindo
classification.
Follow-up (For Cohort Studies)
Routine follow-up examinations at 1, 3, 6, 9, and 12 months postoperatively. Collect
routine
follow-up
indicators
and
assess
the
occurrence
of
postoperative
complications.
Sample Size
The incidence of postoperative complications in gastric cancer patients with severe
sleep apnea is the primary endpoint of this study. Based on previous large-scale
literature reports, the incidence of perioperative cardiovascular complications in
patients with severe sleep apnea undergoing non-cardiac surgery is 15% higher than
in the normal population [8]. Using a power of 90% and a significance level of 5%,
sample size estimation was performed using PASS, version 11 (NCSS, LLC). We need
to recruit 93 patients per group. Accounting for loss to follow-up, dropouts, and
other factors, we plan to include 120 patients per group, totaling an estimated 240
patients for both groups.
Study Flowchart
Gastric cancer patients with severe sleep apnea
-> Apply Inclusion/Exclusion Criteria
-> Undergo surgical treatment
-> Decision on prolonging extubation time?
text
Yes -> Exposure Group: Prolonged extubation time
text
No -> Non-Exposure Group: Non-prolonged extubation time
Compare complication rates between the two groups
-> Follow-up for 1 year
-> Compare complication rates between the two groups
Data Collection and Management
Preoperative patient status: General information (name, gender, age, BMI),

preoperative nutritional status, preoperative tumor marker levels, preoperative
comorbidities, etc.
Postoperative recovery: Time to recovery of bowel function (first flatus, first oral
water/fluid intake), postoperative complications (pulmonary infection, postoperative
gastroparesis, postoperative reflux, inflammatory bowel obstruction, bleeding,
perforation,
anastomosis-related
complications
such
as
anastomotic
leak,
anastomotic
stenosis,
anastomotic
bleeding,
etc.),
cardiovascular
and
cerebrovascular complications, etc.
Postoperative follow-up information: Patient review at 1, 3, 6, 9, and 12 months
postoperatively, CT and gastroscopy results.
Statistical Analysis Methods
Chi-square test or Fisher's exact test will be used to compare categorical variables.
Continuous variables will be expressed as median and IQR if non-normally
distributed and analyzed using the Mann-Whitney U test, or as mean (SD) if normally
distributed and analyzed using the t-test. Survival data will be analyzed using
Kaplan-Meier curves. Enrollment is expected to be completed between June 2025
and June 2026. Follow-up is expected to be completed between June 2026 and June
2027.
Quality Control
During the clinical research process, strictly adhere to the procedures specified in the
clinical study protocol. Collect and enter data completely and accurately. Manage
data using a standardized database.
4. Feasibility Analysis
This is an observational study requiring no additional medical procedures or
expenses, making it technically and economically feasible.
5. Timeline
Enrollment is expected from June 2025 to June 2026.
Follow-up is expected from June 2026 to June 2027.
Data analysis and manuscript writing are expected to be completed by December
2027.
6. References
1.
Sung HA-O, Ferlay J, Siegel RA-O, Laversanne M, Soerjomataram I, Jemal A, Bray F: Global
Cancer Statistics 2020: GLOBOCAN Estimates of Incidence and Mortality Worldwide for
36 Cancers in 185 Countries. (1542-4863 (Electronic)).
2.
Japanese Gastric Cancer Treatment Guidelines 2021 (6th edition). (1436-3305
(Electronic)).
3.
陈裕桦, 高媛, 王连城, 郭子煜, 付善民: 成人阻塞性睡眠呼吸暂停治疗研究进展.
临床口腔医学杂志2023, 39(03):186-189.
4.
潘悦达, 王东博, 韩德民: 我国成人阻塞性睡眠呼吸暂停低通气综合征患病率的

Meta 分析. 医学信息2019, 32(07):73-77+81.
5.
Cadby G, McArdle N, Briffa T, Hillman DR, Simpson L, Knuiman M, Hung J: Severity of
OSA is an independent predictor of incident atrial fibrillation hospitalization in a large
sleep-clinic cohort. (1931-3543 (Electronic)).
6.
Hirotsu C, Haba-Rubio J, Togeiro SM, Marques-Vidal P, Drager LF, Vollenweider P, Waeber
G, Bittencourt L, Tufik S, Heinzer R: Obstructive sleep apnoea as a risk factor for incident
metabolic syndrome: a joined Episono and HypnoLaus prospective cohorts study. LID -
1801150 [pii] LID - 10.1183/13993003.01150-2018 [doi]. (1399-3003 (Electronic)).
7.
Hallowell PT, Stellato Ta Fau - Schuster M, Schuster M Fau - Graf K, Graf K Fau - Robinson
A, Robinson A Fau - Crouse C, Crouse C Fau - Jasper JJ, Jasper JJ: Potentially
life-threatening sleep apnea is unrecognized without aggressive evaluation. (1879-1883
(Electronic)).
8.
Chan MTV, Wang CY, Seet E, Tam S, Lai HY, Chew EFF, Wu WKK, Cheng BCP, Lam CKM,
Short
TG et
al:
Association
of Unrecognized Obstructive
Sleep
Apnea With
Postoperative Cardiovascular Events in Patients Undergoing Major Noncardiac Surgery.
(1538-3598 (Electronic)).
9.
Subramani Y, Singh M Fau - Wong J, Wong J Fau - Kushida CA, Kushida Ca Fau - Malhotra
A, Malhotra A Fau - Chung F, Chung F: Understanding Phenotypes of Obstructive Sleep
Apnea: Applications in Anesthesia, Surgery, and Perioperative Medicine. (1526-7598
(Electronic)).
Filename: 9. Study Protocol v1.5 2025.6.16.docx