Effect of Preoxygenation Position and Examination Position on Hypoxemia During Painless Gastrointestinal Endoscopy
2026年6月24日 更新者：General Hospital of Ningxia Medical University
Effect of Preoxygenation Position and Examination Position on Hypoxemia During Painless Gastrointestinal Endoscopy: A 2×2 Factorial Randomized Controlled Trial
To investigate the independent effects and interaction of pre-oxygenation position (left lateral vs left lateral with 30° head-up tilt) and examination position (left lateral vs left lateral with 30° head-up tilt) on hypoxemia during painless gastroscopy and colonoscopy using a 2×2 factorial design.
調査の概要
状態
まだ募集していません
条件
詳細な説明
Painless gastroscopy and colonoscopy represent core minimally invasive techniques for colorectal cancer screening and the diagnosis and treatment of gastrointestinal diseases. By utilizing intravenous sedation to ensure a pain-free experience, these procedures are widely adopted in clinical practice. However, perioperative hypoxemia remains the most common and critical safety complication during sedation for endoscopy. It is primarily caused by anesthesia-induced respiratory depression, tongue base collapse, airway obstruction, diaphragmatic compression, and restricted thoracic movement, with significantly elevated risks observed in obese, elderly, snoring, and short-necked patients.
Hypoxemia may trigger bradycardia, arrhythmias, myocardial ischemia, and cerebral hypoxia. In severe cases, it can lead to apnea, laryngospasm, and forced termination of the procedure, making it a key indicator in endoscopic anesthesia quality control.
Pre-oxygenation is a fundamental measure to increase functional residual capacity (FRC) and prolong the safe apneic time prior to induction, thereby preventing hypoxemia. The examination position directly determines airway patency, mandibular relaxation, diaphragmatic position, and thoracic compliance throughout the procedure. Both are critical, controllable factors regulating perioperative oxygenation. Studies have confirmed that the left lateral position reduces the incidence of hypoxemia, while the left lateral position with 30° head elevation effectively relaxes the mandible, alleviates tongue base collapse, reduces abdominal organ pressure on the diaphragm, and improves ventilation and oxygenation by increasing FRC.
Current research largely focuses on either the pre-oxygenation position or the examination position in isolation, presenting notable limitations: first, the interaction between these two positions has not been evaluated, leaving the synergistic or antagonistic effects of combined interventions unclear; second, there is a lack of efficient validation using a factorial design, which is necessary to simultaneously analyze the main effects and interactions of both independent variables.
Addressing these clinical challenges and research gaps, this study employs a 2×2 factorial randomized controlled design. With pre-oxygenation position and examination position serving as the two intervention factors, the study aims to explore the individual and combined effects of both factors on perioperative hypoxemia. The objective is to identify the optimal positional combination, establish standardized and generalizable positioning protocols for painless endoscopy, accurately reduce the incidence of hypoxemia, enhance the precision of anesthesia management, and provide high-level evidence to guide clinical practice.
研究の種類
介入
入学 (推定)
208
段階
- 適用できない
連絡先と場所
このセクションには、調査を実施する担当者の連絡先の詳細と、この調査が実施されている場所に関する情報が記載されています。
研究連絡先
- 名前：xiaoyong wei, Master's degree
- 電話番号：86-951-674-3252
- メール：weixy9912@126.com
研究場所
-
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Ningxia
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Yinchuan、Ningxia、中国、750001
- General Hospital of Ningxia Medical University
-
コンタクト：
- xiaoyong wei, Master's degree
- 電話番号：86-951-674-3252
- メール：weixy9912@126.cm
-
-
参加基準
研究者は、適格基準と呼ばれる特定の説明に適合する人を探します。これらの基準のいくつかの例は、人の一般的な健康状態または以前の治療です。
適格基準
就学可能な年齢
- 大人
- 高齢者
健康ボランティアの受け入れ
いいえ
説明
Inclusion Criteria:
- Aged 18 to 75 years, regardless of gender
- Body mass index (BMI): 18.5 - 35 kg/m²
- ASA physical status class I, II or III
- Scheduled for painless gastroscopy, painless colonoscopy, or combined painless gastroenteroscopy
- Able to understand the study procedure and provide written informed consent
Exclusion Criteria:
- Severe cardiopulmonary diseases, including severe COPD, heart failure, severe arrhythmia and pulmonary hypertension
- Difficult airway identified before anesthesia
- Severe obstructive sleep apnea (OSA)
- Spinal or thoracic deformity
- Preoperative baseline hypoxemia
- Known allergy to any anesthetic drugs used in this study
- Pregnant females
- Unable to cooperate with required intraoperative body position
研究計画
このセクションでは、研究がどのように設計され、研究が何を測定しているかなど、研究計画の詳細を提供します。
研究はどのように設計されていますか？
デザインの詳細
- 主な目的：防止
- 割り当て：ランダム化
- 介入モデル：並列代入
- マスキング：独身
武器と介入
参加者グループ / アーム |
介入・治療 |
|---|---|
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アクティブコンパレータ：Group A1B1 (traditional conventional group)
Pre-oxygenated left lateral position + examination in left lateral position
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An angle measuring device is placed beside the head of the examination bed to enable precise adjustment of the head position.
Pre-oxygenation phase: Administer pure oxygen via a standardized mask with tight fit, at a flow rate of 6 L/min; instruct the patient to take deep breaths while receiving continuous oxygen for 3 minutes, maintaining the same body position throughout.
If the position is altered during this phase, discontinue the procedure.
Left lateral pre-oxygenation: The patient assumes a left lateral position on a horizontal bed surface with the head elevated at 0°, supported by pillows to maintain a neutral spine position and avoid excessive neck extension or flexion.
他の名前：
Examination Phase: From the initiation of anesthesia and endoscope insertion until completion of the procedure, the patient's position and head-of-bed angle must remain fixed throughout; any adjustments are prohibited during this phase.
If the position is altered midway through the examination, the patient will be excluded from the study.
Left lateral position examination: The patient assumes a 90-degree left lateral position on a horizontal bed surface with the head of the bed elevated to 0°, supported by pillows to maintain a neutral spinal alignment, avoiding excessive neck extension or flexion.
他の名前：
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実験的：Group A1B2 (improved examination group)
Left lateral position with pre-oxygenation + left head elevated 30° during examination
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An angle measuring device is placed beside the head of the examination bed to enable precise adjustment of the head position.
Pre-oxygenation phase: Administer pure oxygen via a standardized mask with tight fit, at a flow rate of 6 L/min; instruct the patient to take deep breaths while receiving continuous oxygen for 3 minutes, maintaining the same body position throughout.
If the position is altered during this phase, discontinue the procedure.
Left lateral pre-oxygenation: The patient assumes a left lateral position on a horizontal bed surface with the head elevated at 0°, supported by pillows to maintain a neutral spine position and avoid excessive neck extension or flexion.
他の名前：
Examination Phase: From the initiation of anesthesia and endoscope insertion until completion of the procedure, the patient's position and head-of-bed angle must remain fixed throughout; any adjustments are prohibited during this phase.
If the position is altered midway through the examination, the patient will be excluded from the study.
Left lateral decubitus examination: The patient assumes a left lateral position on a horizontal bed surface with the head elevated at 30°, supported by a pillow to maintain a neutral spinal alignment, avoiding excessive neck extension or flexion.
他の名前：
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実験的：Group A2B1 (pre-oxygenation improvement group)
Left-sided head position at 30°, pre-oxygenated air administration + examination in left lateral decubitus position
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Examination Phase: From the initiation of anesthesia and endoscope insertion until completion of the procedure, the patient's position and head-of-bed angle must remain fixed throughout; any adjustments are prohibited during this phase.
If the position is altered midway through the examination, the patient will be excluded from the study.
Left lateral position examination: The patient assumes a 90-degree left lateral position on a horizontal bed surface with the head of the bed elevated to 0°, supported by pillows to maintain a neutral spinal alignment, avoiding excessive neck extension or flexion.
他の名前：
An angle measuring device is placed beside the head of the examination bed to allow precise adjustment of the head position.
Pre-oxygenation phase: The patient receives pure oxygen via a standardized mask with tight fit, at a flow rate of 6 L/min; they are instructed to take deep breaths while receiving continuous oxygen for 3 minutes, maintaining the same body position throughout.
If the position is altered during this phase, the procedure is discontinued.
Left-sided head elevation (30°): During pre-oxygenation, the patient lies in a left lateral position on a horizontal bed surface with the head elevated by 30°, supported by pillows to maintain a neutral spinal alignment and prevent excessive neck extension or flexion.
他の名前：
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実験的：Group A2B2 (double-position improvement group)
Left-sided head height at 30 weeks: pre-oxygenated condition + left-sided head height at 30 weeks examination
|
Examination Phase: From the initiation of anesthesia and endoscope insertion until completion of the procedure, the patient's position and head-of-bed angle must remain fixed throughout; any adjustments are prohibited during this phase.
If the position is altered midway through the examination, the patient will be excluded from the study.
Left lateral decubitus examination: The patient assumes a left lateral position on a horizontal bed surface with the head elevated at 30°, supported by a pillow to maintain a neutral spinal alignment, avoiding excessive neck extension or flexion.
他の名前：
An angle measuring device is placed beside the head of the examination bed to allow precise adjustment of the head position.
Pre-oxygenation phase: The patient receives pure oxygen via a standardized mask with tight fit, at a flow rate of 6 L/min; they are instructed to take deep breaths while receiving continuous oxygen for 3 minutes, maintaining the same body position throughout.
If the position is altered during this phase, the procedure is discontinued.
Left-sided head elevation (30°): During pre-oxygenation, the patient lies in a left lateral position on a horizontal bed surface with the head elevated by 30°, supported by pillows to maintain a neutral spinal alignment and prevent excessive neck extension or flexion.
他の名前：
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この研究は何を測定していますか？
主要な結果の測定
結果測定 |
メジャーの説明 |
時間枠 |
|---|---|---|
|
Incidence of hypoxemia
時間枠：During procedure
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Incidence of SpO₂ ≤ 90% for >10 seconds during the examination.
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During procedure
|
二次結果の測定
結果測定 |
メジャーの説明 |
時間枠 |
|---|---|---|
|
Safe duration of pre-oxygenation
時間枠：During procedure
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Time from cessation of oxygen administration (start of anesthesia induction) to first SpO₂ <92% for ≥3 seconds.
If no desaturation occurs, the value equals the duration from oxygen cessation to end of procedure (right-censored).
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During procedure
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Incidence of subclinical respiratory depression
時間枠：During procedure
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Defined as the proportion of participants experiencing SpO₂ between 90% and 95% (inclusive) at any time during the examination.
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During procedure
|
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Requirement for jaw thrust
時間枠：During procedure
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Number of participants requiring manual jaw thrust to relieve airway obstruction during the examination.
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During procedure
|
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Requirement for nasal cannula oxygen
時間枠：During procedure
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Number of participants requiring oxygen supplementation via nasal cannula during the examination.
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During procedure
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Requirement for increased oxygen flow
時間枠：During procedure
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Number of participants requiring an increase in oxygen flow rate during the examination.
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During procedure
|
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Requirement for mask ventilation
時間枠：During procedure
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Number of participants requiring bag-mask ventilation during the examination.
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During procedure
|
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Requirement for endotracheal intubation
時間枠：During procedure
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Number of participants requiring endotracheal intubation during the examination.
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During procedure
|
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Incidence of airway intervention
時間枠：During procedure
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Proportion of participants requiring any airway intervention (jaw thrust, nasal cannula, increased flow, mask ventilation, or intubation)
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During procedure
|
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Severity of coughing
時間枠：During procedure
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Assessed using a 4-grade scale: Grade I (none), Grade II (single mild episode), Grade III (multiple episodes <15s), Grade IV (continuous >15s)
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During procedure
|
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Length of stay in recovery room
時間枠：Up to 30 minutes post-anesthesia care unit (PACU) admission
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Time from arrival to discharge from the recovery room (maximum observation 30 minutes)
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Up to 30 minutes post-anesthesia care unit (PACU) admission
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Endoscopist satisfaction score
時間枠：During procedure
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Assessed using a Numerical Rating Scale (NRS) ranging from 0 to 10, with higher scores indicating greater satisfaction.
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During procedure
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Incidence of postoperative nausea, vomiting, headache, and dizziness
時間枠：Up to 30 minutes post-anesthesia care unit (PACU) admission
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Proportion of participants experiencing nausea, vomiting, headache, or dizziness after awakening in the recovery room.
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Up to 30 minutes post-anesthesia care unit (PACU) admission
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その他の成果指標
結果測定 |
メジャーの説明 |
時間枠 |
|---|---|---|
|
Safety outcome endpoints：heart rate
時間枠：Baseline and during procedure
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Recorded at T0 (before pre-oxygenation), T1 (before induction), T2 (scope insertion), and T3 (scope removal).
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Baseline and during procedure
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Safety outcome endpoints：blood pressure
時間枠：Baseline and during procedure
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Recorded at T0 (before pre-oxygenation), T1 (before induction), T2 (scope insertion), and T3 (scope removal)
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Baseline and during procedure
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Safety outcome endpoints：peripheral oxygen saturation (SpO₂)
時間枠：Baseline and during procedure
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Recorded at T0 (before pre-oxygenation), T1 (before induction), T2 (scope insertion), and T3 (scope removal).
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Baseline and during procedure
|
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Safety outcome endpoints：Incidence of hemodynamic instability in recovery
時間枠：Up to 30 minutes post-anesthesia care unit (PACU) admission
|
Occurrence of tachycardia (>100 bpm), bradycardia (<50 bpm), or hypotension (systolic blood pressure <80 mmHg) during the recovery period.
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Up to 30 minutes post-anesthesia care unit (PACU) admission
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協力者と研究者
ここでは、この調査に関係する人々や組織を見つけることができます。
捜査官
- スタディチェア：Xinli Ni, Doctoral、General Hospital of Ningxia Medical University
研究記録日
これらの日付は、ClinicalTrials.gov への研究記録と要約結果の提出の進捗状況を追跡します。研究記録と報告された結果は、国立医学図書館 (NLM) によって審査され、公開 Web サイトに掲載される前に、特定の品質管理基準を満たしていることが確認されます。
主要日程の研究
研究開始 (推定)
2026年6月23日
一次修了 (推定)
2026年7月31日
研究の完了 (推定)
2026年8月31日
試験登録日
最初に提出
2026年6月15日
QC基準を満たした最初の提出物
2026年6月24日
最初の投稿 (実際)
2026年6月29日
学習記録の更新
投稿された最後の更新 (実際)
2026年6月29日
QC基準を満たした最後の更新が送信されました
2026年6月24日
最終確認日
2026年6月1日
詳しくは
本研究に関する用語
その他の研究ID番号
- dywe0003
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