Postoperative Hypoxemia
Conditions
Brief summary
Using prospective real-world data, this study aims to determine whether the lateral decubitus position reduces the incidence of post-procedure hypoxemia in patients undergoing painless gastroscopy/colonoscopy, thereby providing a simple, non-invasive, and low-cost optimization strategy for clinical practice.
Detailed description
Painless gastroscopy and colonoscopy have become essential modalities for the screening and diagnosis of digestive tract diseases, with their utilization increasing annually. However, hypoxemia remains the most common complication during these procedures, with reported incidences ranging widely from 1.8% to 69%. Severe hypoxemia can lead to adverse outcomes, including arrhythmias, hemodynamic decompensation, and hypoxic brain injury. Consequently, developing effective strategies to prevent hypoxemia in patients undergoing sedation for gastrointestinal (GI) endoscopy is of significant clinical value. Current clinical research has primarily focused on hypoxemia occurring during the endoscopic procedure itself, whereas there is a paucity of high-quality evidence regarding the incidence and preventive measures of hypoxemia during the recovery phase. Specifically, the impact of body positioning on post-procedural hypoxemia remains largely unexplored. Emerging evidence suggests that the lateral decubitus position significantly reduces the incidence of hypoxemia during adult sedation. Anatomically, in the supine position, residual sedative effects combined with gravity cause the tongue and soft palate-structures lacking bony support-to collapse posteriorly, leading to upper airway obstruction. Conversely, the lateral position helps maintain a patent airway by preventing this collapse and optimizing the ventilation-perfusion (V/Q) matching, thereby stabilizing oxygenation. Despite this theoretical basis, prospective studies investigating the effect of body positioning on recovery-phase hypoxemia in real-world settings are lacking. Therefore, this study hypothesizes that the lateral decubitus position reduces the incidence of recovery-phase hypoxemia compared to the supine position. Using prospective real-world data, we aim to validate this hypothesis and provide a simple, non-invasive, and cost-effective optimization strategy for clinical practice.
Interventions
PROCEDURELateral decubitus position group (Group L)
Upon admission to the Post-Anesthesia Care Unit (PACU), an independent researcher (attending anesthesiologist) assessed the patient using the Ramsay Sedation Scale (1: anxious and agitated; 2: awake, calm, and cooperative; 3: drowsy but responsive to verbal commands; 4: asleep but responsive to tactile stimulation or pain; 5: asleep with a sluggish response to stimulation; 6: deep sleep with no response). Patients in the Lateral Group (Group L) were maintained in the predetermined left lateral position. Standard monitoring was applied, and nasal cannula oxygen was administered at 2 L/min. If SpO₂ remained \>95% for at least 5 minutes, oxygen was discontinued for observation. To ensure strict adherence to the protocol, an independent researcher continuously monitored and verified patient positioning (corrections were made only if the patient rolled unconsciously). Patients were evaluated using the Aldrete discharge scoring system; discharge from the PACU occurred when a score of \>9 was a
PROCEDURESupine position group (Group S)
Upon admission to the Post-Anesthesia Care Unit (PACU), an independent researcher (attending anesthesiologist) assessed the patient using the Ramsay Sedation Scale (1: anxious and agitated; 2: awake, calm, and cooperative; 3: drowsy but responsive to verbal commands; 4: asleep but responsive to tactile stimulation or pain; 5: asleep with a sluggish response to stimulation; 6: deep sleep with no response). Patients in the Supine Group (Group S) were turned from the predetermined lateral position to the supine position without a head pillow (head-of-bed elevation at 0 degrees). Standard monitoring was applied, and nasal cannula oxygen was administered at 2 L/min. If SpO₂ remained \>95% for at least 5 minutes, oxygen was discontinued for observation. To ensure strict adherence to the protocol, an independent researcher continuously monitored and verified patient positioning (corrections were made only if the patient rolled unconsciously). Patients were evaluated using the Aldrete discharge
Sponsors
General Hospital of Ningxia Medical University
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Subject)
Masking description
Random sequence generation was performed by an independent statistician using computer-generated codes. Allocation concealment was maintained using sequentially numbered, opaque, sealed envelopes (SNOSE), which were opened immediately prior to intervention implementation. Due to the nature of the intervention (body positioning), blinding of participants and personnel was not feasible; however, outcome assessors were blinded, and objective outcome measures were utilized to minimize detection bias."
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
1. Age ≥ 18 years. 2. Both sexes. 3. American Society of Anesthesiologists (ASA) physical status classification I-III. 4. Scheduled for combined painless esophagogastroduodenoscopy/colonoscopy or either of the two procedures. 5. Ability to understand the study protocol and provide written informed consent. 6. A broad set of inclusion criteria was adopted to enroll a patient population that better reflects routine clinical practice. The study aimed to enhance the generalizability of the findings by including patients with various comorbidities, such as preprocedural hypoxemia (room-air SpO₂ ≤ 90%), history of pulmonary surgery, obstructive sleep apnea (OSA), and other pulmonary conditions (including asthma, COPD, chronic bronchitis, emphysema, and pulmonary bullae).
Exclusion criteria
1. Severe cardiovascular or cerebrovascular diseases. 2. Pregnant patients. 3. History of hypersensitivity to ciprofol. Withdrawal Criteria: 1. Endotracheal intubation required during the procedure. 2. Voluntary withdrawal requested by the patient or their legal representative.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Incidence of recovery-phase hypoxemia, | From PACU admission until discharge, assessed up to 30 minutes | Proportion of participants experiencing hypoxemia (SpO₂ ≤ 90% lasting \>10 seconds) during the post-procedure recovery period. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Incidence of Severe Hypoxemia During Recovery | From PACU admission until discharge, assessed up to 30 minutes | Proportion of participants experiencing severe hypoxemia, defined as pulse oxygen saturation (SpO₂) \< 85% lasting \>10 seconds during the post-procedure recovery period. |
| Incidence of Subclinical Respiratory Depression during Recovery | From PACU admission until discharge, assessed up to 30 minutes. | Proportion of participants experiencing subclinical respiratory depression, defined as any episode of pulse oxygen saturation (SpO₂) in the range of 90% to \<95% (inclusive of 90%, exclusive of 95%) during the post-procedure recovery period. |
| Overall Incidence of Airway Intervention During Recovery | From PACU admission until discharge, assessed up to 30 minutes | Proportion of participants requiring any grade of airway intervention (increase oxygen flow, chin lift, mask ventilation, or reintubation) during recovery. |
| Cough Severity Grade During Recovery | From PACU admission until discharge, assessed up to 30 minutes | Severity of cough assessed during the recovery period, graded as: Grade I: No cough, smooth breathing; Grade II: Single mild cough; Grade III: Multiple coughs lasting \<15 seconds; Grade IV: Continuous coughing lasting ≥15 seconds. Reported as the proportion of participants reaching each grade (I-IV). |
| Length of Stay in Post-Anesthesia Care Unit (PACU) | From PACU admission until discharge | Time from admission to the post-anesthesia care unit (PACU) until discharge criteria are met (modified Aldrete score ≥9 on three consecutive assessments), recorded in minutes. |
| Respiratory Comfort Score During Recovery | From PACU admission until discharge, assessed up to 30 minutes | Patient-reported respiratory comfort assessed using a Numerical Rating Scale (NRS) ranging from 0 (worst discomfort) to 10 (greatest comfort) |
| PACU Nurse Satisfaction Score | From PACU admission until discharge, assessed up to 30 minutes | Nurse-assessed satisfaction with patient respiratory stability and overall recovery management, rated using a Numerical Rating Scale (NRS) ranging from 0 (lowest satisfaction) to 10 (highest satisfaction), recorded at patient discharge from the post-anesthesia care unit. |
| Incidence of Tachycardia During Recovery | From PACU admission until discharge, assessed up to 30 minutes | Proportion of participants experiencing tachycardia (heart rate \>100 beats/min) during the post-procedure recovery period. |
| Incidence of Bradycardia During Recovery | From PACU admission until discharge, assessed up to 30 minutes | Proportion of participants experiencing bradycardia (heart rate \<50 beats/min) during recovery. |
| Incidence of Hypotension During Recovery | From PACU admission until discharge, assessed up to 30 minutes | Proportion of participants experiencing hypotension (systolic blood pressure \<80 mmHg) during recovery. |
| Incidence of Nausea or Vomiting During Recovery | From PACU admission until discharge, assessed up to 30 minutes | Proportion of participants experiencing nausea (subjective complaint) or vomiting (objective expulsion of gastric contents) during recovery. |
| Incidence of Laryngospasm During Recovery | From PACU admission until discharge, assessed up to 30 minutes | Proportion of participants experiencing laryngospasm (acute upper airway obstruction with stridor/inability to ventilate, resolving with intervention) during recovery. |
Countries
China
Contacts
CONTACTXiaoyong Wei, Degree
STUDY_CHAIRXinli Ni, Doctoral
86-951-674-3252
Outcome results
None listed