Transnasal Microstream EtCO2 Reduces Hypoxemia During Emergence in Aged Post-Abdomen Surgery
For patients and families
In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- The protocol lists: EtCO₂ Monitoring, Routine Monitoring.
- Who it may be relevant to
- Registry conditions: Elderly Patients, Laparoscopic Surgery, Postoperative Hypoxemia, Capnography. Basic parameters: 65 years — 80 years · All.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- Center list to be confirmed — check the primary protocol.
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
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Official title
Effect of Transnasal Microstream Capnography on Incidence of Hypoxemia During Emergence From General Anesthesia in Elderly Patients After Abdominal Surgery: A Prospective Randomised Controlled Trial
Overview
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).
Detailed description
Study Title:
Effect of Transnasal Microstream End-Tidal Carbon Dioxide Monitoring on the Incidence of Postoperative Hypoxemia in Elderly Patients Undergoing Laparoscopic Surgery under General Anesthesia with Endotracheal Intubation: A Prospective, Randomized Controlled Study
Principal Investigator: Wu Jianbo Department: Anesthesiology and Perioperative Medicine
Background \& Objective:
Postoperative hypoxemia is a common respiratory complication in the post-anesthesia care unit (PACU). Conventional pulse oximetry (SpO₂) has a delayed response to hypoventilation, especially during supplemental oxygen therapy. This study aims to investigate whether adding transnasal microstream end-tidal carbon dioxide (EtCO₂) monitoring in the PACU reduces the incidence of hypoxemia in elderly patients after laparoscopic surgery under general anesthesia.
Study Design:
Prospective, randomized, controlled, interventional study.
Participants:
324 elderly patients (age 65-80 years, ASA I-III, BMI 18-30 kg/m²) scheduled for elective laparoscopic surgery under general anesthesia with endotracheal intubation.
Interventions:
Control group (n=162): Routine monitoring with SpO₂ and clinical observation; oxygen delivery at 2 L/min via sampling line without EtCO₂ monitoring.
Experimental group (n=162): Same oxygen delivery plus continuous real-time transnasal microstream EtCO₂ monitoring.
Primary Outcome:
Incidence of postoperative hypoxemia (SpO₂ \< 90% for \>15 seconds) after extubation in the PACU.
Secondary Outcomes:
Incidence of severe hypoxemia (SpO₂ \< 85% for \>15 seconds) Lowest SpO₂ during PACU stay Vital signs at predefined time points
PACU length of stay (Steward Recovery Score ≥ 4)
Other adverse events (e.g., nausea, vomiting, agitation, shivering)
Safety Monitoring:
Device-related adverse events (nasal irritation, bleeding), respiratory events (bradypnea, apnea, airway obstruction), and serious adverse events (e.g., need for advanced airway, cardiovascular events) will be recorded and managed according to a stepwise intervention protocol.
Randomization and Blinding:
1:1 randomization using block randomization (SAS 9.4) with allocation concealment (sealed, opaque envelopes). Partial blinding: participants, outcome assessors, and statisticians blinded; anesthesiologists/operators unblinded.
Sample Size Calculation:
Based on pilot data (expected hypoxemia rate: 33% in control vs. 18% in experimental group), α=0.05, power=80%, plus 20% dropout → 162 patients per group (total N=324).
Statistical Analysis:
SPSS 22.0 will be used. Continuous variables (normal distribution) will be compared using t-test; non-normally distributed variables using Mann-Whitney U test. Categorical variables (e.g., hypoxemia incidence) will be compared using chi-square or Fisher's exact test.
Expected Significance:
This study will provide high-level evidence on whether transnasal microstream EtCO₂ monitoring in the PACU can enhance respiratory safety in elderly patients recovering from laparoscopic surgery, potentially reducing hypoxemia and related complications.
Interventions
- Device EtCO₂ Monitoring
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. - Other Routine Monitoring
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.
Primary outcome measures
- Incidence of post-extubation hypoxemia (SpO₂ < 90% for >15 seconds) [Time frame: During the period in the post-anesthesia care unit (PACU) (up to 1 days)]
Secondary outcome measures (7)
- Incidence of severe hypoxemia: proportion of patients with SpO₂ < 85% lasting > 15 seconds [Time frame: 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 [Time frame: During the period in the post-anesthesia care unit (PACU) (up to 1 days)]
- PACU length of stay [Time frame: During the period in the post-anesthesia care unit (PACU) (up to 1 days)]
- Other adverse events [Time frame: 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 [Time frame: During the period in the post-anesthesia care unit (PACU) (up to 1 days)]
- Record the patient's blood pressure after admission to the PACU [Time frame: During the period in the post-anesthesia care unit (PACU) (up to 1 days)]
- Record the changes in the patient's SpO₂ values after admission to the PACU [Time frame: During the period in the post-anesthesia care unit (PACU) (up to 1 days)]
Eligibility criteria
Inclusion criteria
- 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
Exclusion criteria
- 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.
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: Yes
Study design
- Allocation
- Randomized
- Model
- Parallel assignment
- Masking
- Triple blind
- Primary purpose
- Prevention
Study locations
Center list to be confirmed — check the primary protocol.
Identifiers
NCT: NCT07652385 · YXLL-KY-2026(147)