Transnasal Microstream EtCO2 Reduces Hypoxemia During Emergence in Aged Post-Abdomen Surgery

NCT07652385 | Not Yet Recruiting

• 1 other identifier: YXLL-KY-2026(147)
• Study Type: interventional
• Target: 324
• Locations: 0 countries
• Sites: N/A

Brief Summary

This prospective, randomized controlled study aims to investigate whether transnasal microstream end-tidal carbon dioxide (EtCO₂) monitoring in the post-anesthesia care unit (PACU) reduces the incidence of postoperative hypoxemia in elderly patients (65-80 years, ASA I-III, BMI 18-30 kg/m²) undergoing elective laparoscopic surgery under general anesthesia with endotracheal intubation. A total of 324 patients will be randomized 1:1 to either the control group (standard SpO₂ monitoring and clinical observation with oxygen delivery at 2 L/min via sampling line) or the experimental group (same oxygen delivery plus continuous real-time transnasal microstream EtCO₂ monitoring). The primary outcome is the incidence of hypoxemia (SpO₂ \< 90% for \>15 seconds) after extubation in the PACU. Secondary outcomes include severe hypoxemia (SpO₂ \< 85%), lowest SpO₂ during PACU stay, vital signs at specified time points, PACU length of stay, and other adverse events. Statistical analysis will use chi-square or Fisher's exact test for the primary outcome, with a sample size calculated to detect a reduction in hypoxemia from 33% (control) to 18% (experimental group) (α=0.05, power=80%, plus 20% dropout).

Conditions

Elderly Patients; Laparoscopic Surgery; Postoperative Hypoxemia; Capnography

Outcome Measures

Primary Outcomes (1)

• Incidence of post-extubation hypoxemia (SpO₂ < 90% for >15 seconds)

  Closely monitor vital signs, and record the number of episodes of hypoxemia (defined as SpO₂ \< 90% lasting for \>15 seconds) following tracheal extubation after the patient is transferred from the operating room to the PACU.more than 15 seconds

  During the period in the post-anesthesia care unit (PACU) (up to 1 days)

Secondary Outcomes (7)

• Incidence of severe hypoxemia: proportion of patients with SpO₂ < 85% lasting > 15 seconds

  During the period in the post-anesthesia care unit (PACU) (up to 1 days)

• Lowest SpO₂ value during PACU stay Lowest SpO₂ value during PACU stay Lowest SpO₂ value during PACU stay

  During the period in the post-anesthesia care unit (PACU) (up to 1 days)

• PACU length of stay

  During the period in the post-anesthesia care unit (PACU) (up to 1 days)

• Other adverse events

  During the period in the post-anesthesia care unit (PACU) (up to 1 days)

• Record the changes in heart rate following the patient's admission to the PACU

  During the period in the post-anesthesia care unit (PACU) (up to 1 days)

Study Arms (2)

Control Group (Routine Monitoring Group)

ACTIVE COMPARATOR

After endotracheal extubation, the sampling end of the sampling line is placed between the patient's mouth and nose, and oxygen is delivered at 2 L/min via the sampling line. The patient receives only routine monitoring (including continuous pulse oximetry and clinical observation) and is not connected to the end-tidal carbon dioxide (EtCO₂) monitoring device.

Other: Routine Monitoring

Experimental Group (EtCO₂ Monitoring Group)

EXPERIMENTAL

After endotracheal extubation, the sampling end of the sampling line is placed between the patient's mouth and nose, and oxygen is delivered at 2 L/min via the sampling line. At the same time, the sampling line is connected to the monitor to initiate continuous real-time transnasal microstream end-tidal carbon dioxide monitoring.

Device: EtCO₂ Monitoring

Interventions

EtCO₂ Monitoring DEVICE

After extubation, the sampling line is placed between the patient's mouth and nose to deliver oxygen at 2 L/min. The sampling line is connected to a patient monitor (RespArrayTM) to initiate continuous real-time transnasal microstream end-tidal carbon dioxide (EtCO₂) monitoring throughout the post-anesthesia care unit (PACU) stay.

Experimental Group (EtCO₂ Monitoring Group)

Routine Monitoring OTHER

After extubation, the sampling line is placed between the patient's mouth and nose to deliver oxygen at 2 L/min. The patient receives routine monitoring including continuous pulse oximetry (SpO₂) and clinical observation, but is not connected to the EtCO₂ monitoring device.

Control Group (Routine Monitoring Group)

Eligibility Criteria

• Age: 65 Years - 80 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Older Adult (65+)

You may qualify if:

• Age 65-80 years;
• ASA physical status I-III;
• BMI 18-30 kg/m²;
• Participants scheduled for elective laparoscopic surgery under general anesthesia with endotracheal intubation;
• Willing to participate in the study and provide written informed consent

You may not qualify if:

• Patients with nasal bleeding, nasal mucosal injury, nasal cavity occupancy, or other conditions that preclude transnasal carbon dioxide monitoring;
• Patients undergoing emergency surgery;
• Participants requiring postoperative assisted ventilation via endotracheal intubation or tracheostomy;
• Presence of any disease or condition that may cause abnormal end-tidal carbon dioxide waveforms or abnormal baseline pulse oximetry (e.g., congenital heart disease or chronic lung disease);
• Severe cardiac insufficiency (≤4 Metabolic Equivalents \[MetS\]);
• Severe renal insufficiency (acute kidney injury \[AKI\] or chronic kidney disease \[CKD\] stage 4 or higher);
• Severe hepatic insufficiency (Child-Pugh class C or worse);
• Allergy to study medications;
• Daily alcohol intake ≥60 grams;
• History of psychiatric disorders such as depression, severe central nervous system depression, Parkinson's disease, basal ganglion lesions, schizophrenia, epilepsy, Alzheimer's disease;
• Participation in another related clinical study within the past 3 months.

Sponsors & Collaborators

• Jianbo Wu: lead

Study Officials

• Jianbo WU, Doctoral

  Shandong First Medical University

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Jianbo WU

CONTACT

18560083793; jianbowu@sdu.edu.cn

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, INVESTIGATOR, OUTCOMES ASSESSOR
• Masking Details: This is a partially masked (single-blind) study. Participants (under sedation and unaware of group assignment), outcome assessors, and the statistician are masked to group allocation. The anesthesia provider who performs the intervention cannot be masked because the EtCO₂ monitoring interface is visible only in the experimental group. Randomization is concealed using sequentially numbered, sealed, opaque envelopes, and the allocation is revealed after extubation just before the intervention. The statistician receives only coded data (Group A/B) and remains blinded until the final analysis is completed.
• Purpose: PREVENTION
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR INVESTIGATOR
• PI Title: Department Director

Model Details: Participants are randomly assigned in a 1:1 ratio to either the experimental group (transnasal microstream end-tidal carbon dioxide monitoring) or the control group (conventional monitoring with oxygen delivery only, without EtCO₂ monitoring).

Study Record Dates

• First Submitted: June 5, 2026
• First Posted: June 17, 2026
• Study Start (Estimated): July 1, 2026
• Primary Completion (Estimated): July 1, 2028
• Study Completion (Estimated): October 1, 2028
• Last Updated: June 17, 2026

Record last verified: 2026-06

Data Sharing

• IPD Sharing: Will not share