Residual Neuromuscular BlockadeDIAPHEXNCT07912437
Diaphragm Ultrasound and Neuromuscular Monitoring for Predicting Early Respiratory Events After Extubation
An observational study of Residual Neuromuscular Blockade and Diaphragm Dysfunction, run by Mustafa Duran.
Trial summary
The goal of this prospective observational study is to learn whether diaphragm ultrasound and quantitative neuromuscular monitoring can predict early respiratory events after extubation in adults having elective surgery under general anesthesia. Read more about this study
- Who is it for?
- Ages 18 to 75 years
- Conditions the study is for
- Residual Neuromuscular Blockade, Diaphragm Dysfunction, Postoperative Pulmonary Complications
- What is being tested?
- Diaphragm ultrasonography4
- How many people
- 100 participants
- Where
- No sites listed yet
- Study dates
- 1 Nov 2026to 10 Jan 2027
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 75 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: Consecutive adult patients (18-75 years, ASA I-III) scheduled for elective surgery in the supine position under general anesthesia with neuromuscular blockade at Marmara University Pendik Training and Research Hospital, Istanbul, Türkiye.
Who may be able to join
- Age 18-75 years
- ASA physical status I-III
- Elective surgery under general anesthesia
- Supine position during surgery
- Use of a neuromuscular blocking agent during surgery
- Quantitative TOF monitoring available before extubation
- Adequate ultrasound window for diaphragm assessment
- Written informed consent
Who cannot join
- Refusal to participate
- Emergency surgery
- ASA physical status IV or higher
- Pregnancy
- Known diaphragm paralysis or phrenic nerve injury
- Previous diaphragm or thoracic surgery
Show all 13Show fewer
- Moderate-to-severe COPD, advanced restrictive lung disease or severe respiratory failure
- Neuromuscular disease (e.g., myasthenia gravis, myopathy)
- Preoperative need for invasive or non-invasive mechanical ventilation
- Hemodynamic instability or vasopressor requirement
- Inability to obtain diaphragm ultrasound images
- Extubation not planned at the end of surgery
- Planned postoperative intensive care unit admission
Trial locations and contacts
No sites are listed yet. Contact the study team or a site near you to ask about taking part.
Marmara University Pendik Training and Research Hospital, Depa contact
About this study
Official title: Evaluation of the Relationship Between Diaphragm Ultrasonography, Neuromuscular Monitoring Parameters and Extubation Success in Patients Undergoing Elective Surgery: A Prospective Observational Study
The goal of this prospective observational study is to learn whether diaphragm ultrasound and quantitative neuromuscular monitoring can predict early respiratory events after extubation in adults having elective surgery under general anesthesia.
The main questions it aims to answer are:
Read more
- Are lower diaphragm thickening fraction and diaphragm excursion before extubation associated with early respiratory events after extubation?
- How well do diaphragm ultrasound parameters and the train-of-four (TOF) ratio predict these events?
Participants will receive their usual anesthesia care. Diaphragm ultrasound will be performed at four time points: before induction of anesthesia, 5 minutes after induction, before extubation, and 30 minutes after extubation in the post-anesthesia care unit (PACU). The TOF ratio will be recorded with routine quantitative neuromuscular monitoring. Respiratory events will be recorded from extubation until discharge from the PACU.
Read the detailed description
Safe extubation after general anesthesia depends on adequate recovery of respiratory muscle function. In routine practice, extubation decisions are based on clinical criteria and, when available, a TOF ratio of 0.9 or higher. However, a normal TOF ratio measured at the adductor pollicis does not always reflect full functional recovery of the diaphragm. Diaphragm ultrasonography is a non-invasive bedside method that allows direct assessment of diaphragm thickness, diaphragm thickening fraction (DTF) and diaphragm excursion. Most studies evaluating diaphragm ultrasound for extubation have been performed in intensive care unit patients; data in patients extubated in the operating room after elective surgery are limited.
This single-center, prospective observational cohort study will be conducted at Marmara University Pendik Training and Research Hospital, Department of Anesthesiology and Reanimation. Adult patients (18-75 years, ASA I-III) undergoing elective surgery in the supine position under general anesthesia with neuromuscular blockade will be included after written informed consent.
Ultrasound protocol: The right hemidiaphragm will be assessed in the supine position. Diaphragm thickness at end-inspiration (Tinsp) and end-expiration (Texp) will be measured with a linear probe at the zone of apposition, and DTF will be calculated as (Tinsp - Texp) / Texp x 100. Diaphragm excursion will be measured with M-mode ultrasound. Measurements will be obtained at four time points: before induction (T0), 5 minutes after induction under controlled ventilation (T1), before extubation during spontaneous breathing with the patient cooperative (T2), and 30 minutes after extubation in the PACU (T3). Each parameter will be measured three times and the mean value will be used.
Neuromuscular monitoring: The neuromuscular blocking agent, total dose (mg and mg/kg), time from last dose to extubation, reversal agent and dose, and the TOF ratio at extubation will be recorded.
The extubation decision will be made by the attending anesthesiologist according to routine clinical assessment, independent of the study measurements. Patients will be observed in the PACU for at least 30 minutes after extubation.
Statistical analysis: Patients with and without early respiratory events will be compared using the t-test or Mann-Whitney U test for continuous variables and the chi-square or Fisher exact test for categorical variables. Changes in diaphragm parameters across time points will be analyzed with repeated-measures ANOVA or the Friedman test. Correlation between diaphragm parameters and the TOF ratio will be assessed with Pearson or Spearman correlation. Independent predictors of early respiratory events will be identified with logistic regression, and the predictive performance of diaphragm parameters will be evaluated with ROC analysis (AUC, sensitivity, specificity, optimal cut-off). A sample size of 90 patients was calculated (two-tailed, effect size d = 0.60, alpha = 0.05, power = 0.80); 100 patients will be enrolled to account for possible data loss.
- Conditions
- Residual Neuromuscular Blockade, Diaphragm Dysfunction, Postoperative Pulmonary Complications, Airway Extubation
- Being tested
- Diaphragm ultrasonography4
- Keywords
- Diaphragm Ultrasound, Diaphragmatic Excursion, Diaphragm Thickening Fraction, Train-of-Four Monitoring, Neuromuscular Monitoring, General Anesthesia
- Medical subject headings
- Delayed Emergence from Anesthesia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Diaphragm ultrasonography4Diagnostic test
Right hemidiaphragm ultrasonography in the supine position. Diaphragm thickness at end-inspiration and end-expiration is measured with a linear probe at the zone of apposition, and diaphragm thickening fraction is calculated. Diaphragm excursion is measured with M-mode. Each parameter is measured three times at four time points: before induction, 5 minutes after induction, before extubation, and 30 minutes after extubation in the PACU.
| Study group | Role | What they receive |
|---|---|---|
| Elective surgery patients under general anesthesia | Adult patients (18-75 years, ASA I-III) undergoing elective surgery in the supine position under general anesthesia with neuromuscular blockade and planned extubation at the end of surgery. Receives: Diagnostic Test: Diaphragm ultrasonography4 |
What is being measured
The primary outcome is the main question the study is designed to answer.
Incidence of early postoperative respiratory events
Composite of any of the following: SpO₂ < 92% lasting at least 30 seconds; airway obstruction requiring jaw thrust; need for mask ventilation; laryngospasm; apnea (at least 15 seconds) or hypoventilation (respiratory rate < 8/min for at least 1 minute); need for non-invasive ventilation; reintubation.
Measured: From tracheal extubation until discharge from the post-anesthesia care unit (PACU), assessed up to 2 hours
Secondary outcomes (6)
Predictive accuracy of diaphragm thickening fraction
Area under the ROC curve, sensitivity, specificity and optimal cut-off of DTF measured before extubation for predicting early respiratory events.
Measured: Diaphragm measured immediately before tracheal extubation (T2); respiratory events assessed from extubation until PACU discharge, up to 2 hours
Predictive accuracy of diaphragm excursion
Area under the ROC curve, sensitivity, specificity and optimal cut-off of diaphragm excursion (cm) measured before extubation for predicting early respiratory events.
Measured: Diaphragm measured immediately before tracheal extubation (T2); respiratory events assessed from extubation until PACU discharge, up to 2 hours
Change in diaphragm thickening fraction from baseline
Percentage change in DTF before extubation compared with the pre-induction value.
Measured: Before induction (T0) and before extubation (T2)
Diaphragm parameters across time points
Diaphragm thickness, DTF (%) and excursion (cm) at four time points.
Measured: Before induction (T0), 5 minutes after induction (T1), before extubation (T2), 30 minutes after extubation (T3)
Correlation between TOF ratio and diaphragm parameters
Correlation coefficient between the TOF ratio at extubation and DTF and diaphragm excursion before extubation.
Measured: Immediately before tracheal extubation
Incidence of individual respiratory events
Incidence of each component of the primary composite outcome.
Measured: From tracheal extubation until discharge from the post-anesthesia care unit (PACU), assessed up to 2 hours
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted3 Nov 2026
- Study start1 Nov 2026 (estimated)
- Primary completion1 Jan 2027 (estimated)
- Study completion10 Jan 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Residual Neuromuscular BlockadeStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 100 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Mustafa Duran
- Sponsor type
- University, hospital or other
- Collaborators
- Marmara University Pendik Training and Research Hospital
- Responsible party
- Sponsor-investigator, Mustafa Duran, Kocaeli University
- Investigators
- mustafa duran, md, Principal investigator, Marmara University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07912437
- Sponsor's protocol ID
- 09.2026.26-0788
- Acronym
- DIAPHEX
- Status last verified
- Oct 2026
- First submitted
- 22 Oct 2026
- Last updated
- 3 Nov 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Individual participant data will not be shared publicly; de-identified data may be made available by the principal investigator upon reasonable request.
Study at a glance
From the registry record, last updated by the sponsor on 3 Nov 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Evaluation of the Relationship Between Diaphragm Ultrasonography, Neuromuscular Monitoring Parameters and Extubation Success in Patients Undergoing Elective Surgery: A Prospective Observational Study
- ClinicalTrials.gov ID
- NCT07912437
- Acronym / sponsor ID
- DIAPHEX / 09.2026.26-0788
- Conditions
- Residual Neuromuscular Blockade, Diaphragm Dysfunction, Postoperative Pulmonary Complications, Airway Extubation
- Keywords
- Diaphragm Ultrasound, Diaphragmatic Excursion, Diaphragm Thickening Fraction, Train-of-Four Monitoring, Neuromuscular Monitoring, General Anesthesia
- Study type
- Observational
- Recruitment status
- Not yet recruiting
- Enrolment
- 100 participants (estimated)
- Lead sponsor
- Mustafa DuranUniversity, hospital or other
- Collaborators
- Marmara University Pendik Training and Research Hospital
- Study start
- 1 Nov 2026 (estimated)
- Primary completion
- 1 Jan 2027 (estimated)
- Study completion
- 10 Jan 2027 (estimated)
- First posted
- 3 Nov 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The goal of this prospective observational study is to learn whether diaphragm ultrasound and quantitative neuromuscular monitoring can predict early respiratory events after extubation in adults having elective surgery under general anesthesia.
The main questions it aims to answer are:
- Are lower diaphragm thickening fraction and diaphragm excursion before extubation associated with early respiratory events after extubation?
- How well do diaphragm ultrasound parameters and the train-of-four (TOF) ratio predict these events?
Participants will receive their usual anesthesia care. Diaphragm ultrasound will be performed at four time points: before induction of anesthesia, 5 minutes after induction, before extubation, and 30 minutes after extubation in the post-anesthesia care unit (PACU). The TOF ratio will be recorded with routine quantitative neuromuscular monitoring. Respiratory events will be recorded from extubation until discharge from the PACU.
Detailed description
Safe extubation after general anesthesia depends on adequate recovery of respiratory muscle function. In routine practice, extubation decisions are based on clinical criteria and, when available, a TOF ratio of 0.9 or higher. However, a normal TOF ratio measured at the adductor pollicis does not always reflect full functional recovery of the diaphragm. Diaphragm ultrasonography is a non-invasive bedside method that allows direct assessment of diaphragm thickness, diaphragm thickening fraction (DTF) and diaphragm excursion. Most studies evaluating diaphragm ultrasound for extubation have been performed in intensive care unit patients; data in patients extubated in the operating room after elective surgery are limited.
This single-center, prospective observational cohort study will be conducted at Marmara University Pendik Training and Research Hospital, Department of Anesthesiology and Reanimation. Adult patients (18-75 years, ASA I-III) undergoing elective surgery in the supine position under general anesthesia with neuromuscular blockade will be included after written informed consent.
Ultrasound protocol: The right hemidiaphragm will be assessed in the supine position. Diaphragm thickness at end-inspiration (Tinsp) and end-expiration (Texp) will be measured with a linear probe at the zone of apposition, and DTF will be calculated as (Tinsp - Texp) / Texp x 100. Diaphragm excursion will be measured with M-mode ultrasound. Measurements will be obtained at four time points: before induction (T0), 5 minutes after induction under controlled ventilation (T1), before extubation during spontaneous breathing with the patient cooperative (T2), and 30 minutes after extubation in the PACU (T3). Each parameter will be measured three times and the mean value will be used.
Neuromuscular monitoring: The neuromuscular blocking agent, total dose (mg and mg/kg), time from last dose to extubation, reversal agent and dose, and the TOF ratio at extubation will be recorded.
The extubation decision will be made by the attending anesthesiologist according to routine clinical assessment, independent of the study measurements. Patients will be observed in the PACU for at least 30 minutes after extubation.
Statistical analysis: Patients with and without early respiratory events will be compared using the t-test or Mann-Whitney U test for continuous variables and the chi-square or Fisher exact test for categorical variables. Changes in diaphragm parameters across time points will be analyzed with repeated-measures ANOVA or the Friedman test. Correlation between diaphragm parameters and the TOF ratio will be assessed with Pearson or Spearman correlation. Independent predictors of early respiratory events will be identified with logistic regression, and the predictive performance of diaphragm parameters will be evaluated with ROC analysis (AUC, sensitivity, specificity, optimal cut-off). A sample size of 90 patients was calculated (two-tailed, effect size d = 0.60, alpha = 0.05, power = 0.80); 100 patients will be enrolled to account for possible data loss.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Elective surgery patients under general anesthesia | – | Diagnostic Test: Diaphragm ultrasonography4Adult patients (18-75 years, ASA I-III) undergoing elective surgery in the supine position under general anesthesia with neuromuscular blockade and planned extubation at the end of surgery. |
Who may qualify
- Ages
- 18 to 75 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Consecutive adult patients (18-75 years, ASA I-III) scheduled for elective surgery in the supine position under general anesthesia with neuromuscular blockade at Marmara University Pendik Training and Research Hospital, Istanbul, Türkiye.
Key inclusion criteria (8 listed)
- Age 18-75 years
- ASA physical status I-III
- Elective surgery under general anesthesia
- Supine position during surgery
- Use of a neuromuscular blocking agent during surgery
Key exclusion criteria (13 listed)
- Refusal to participate
- Emergency surgery
- ASA physical status IV or higher
- Pregnancy
- Known diaphragm paralysis or phrenic nerve injury
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Diaphragm ultrasonography4Right hemidiaphragm ultrasonography in the supine position. Diaphragm thickness at end-inspiration and end-expiration is measured with a linear probe at the zone of apposition, and diaphragm thickening fraction is calculated. Diaphragm excursion is measured with M-mode. Each parameter is measured three times at four time points: before induction, 5 minutes after induction, before extubation, and 30 minutes after extubation in the PACU. | Diagnostic test | Elective surgery patients under general anesthesia |
Primary outcome
Incidence of early postoperative respiratory events
Time frame: From tracheal extubation until discharge from the post-anesthesia care unit (PACU), assessed up to 2 hours
Composite of any of the following: SpO₂ < 92% lasting at least 30 seconds; airway obstruction requiring jaw thrust; need for mask ventilation; laryngospasm; apnea (at least 15 seconds) or hypoventilation (respiratory rate < 8/min for at least 1 minute); need for non-invasive ventilation; reintubation.
6 secondary outcomes
Predictive accuracy of diaphragm thickening fraction
Time frame: Diaphragm measured immediately before tracheal extubation (T2); respiratory events assessed from extubation until PACU discharge, up to 2 hours
Predictive accuracy of diaphragm excursion
Time frame: Diaphragm measured immediately before tracheal extubation (T2); respiratory events assessed from extubation until PACU discharge, up to 2 hours
Change in diaphragm thickening fraction from baseline
Time frame: Before induction (T0) and before extubation (T2)
Diaphragm parameters across time points
Time frame: Before induction (T0), 5 minutes after induction (T1), before extubation (T2), 30 minutes after extubation (T3)
Correlation between TOF ratio and diaphragm parameters
Time frame: Immediately before tracheal extubation
Incidence of individual respiratory events
Time frame: From tracheal extubation until discharge from the post-anesthesia care unit (PACU), assessed up to 2 hours
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 3 Nov 2026.
- Individual participant dataSharing planned: No. Individual participant data will not be shared publicly; de-identified data may be made available by the principal investigator upon reasonable request.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Marmara University Pendik Training and Research Hospital, Depa contact
mustafa duran, md principal investigator
Marmara University
Questions about this trial
What is this clinical trial studying?
An observational study of Residual Neuromuscular Blockade and Diaphragm Dysfunction, run by Mustafa Duran.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 8 inclusion and 13 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 3 Nov 2026. Status can change between updates, so confirm with the study contact before making plans.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact mustafa duran, md (05077933373, duranmustafaa@gmail.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Incidence of early postoperative respiratory events (time frame: From tracheal extubation until discharge from the post-anesthesia care unit (PACU), assessed up to 2 hours). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 3 Nov 2026; AzTrials last refreshed its copy on 8 Nov 2026.