- ICH GCP
- US Clinical Trials Registry
- Clinical Trial NCT02961920
The Effect of Prolonged Inspiratory Time on Pulmonary Mechanics in Obese Patients
The Influence of Prolonged Inspiratory Time on Respiratory Mechanics and Oxygenation in Obese Patients Undergoing Spine Surgery in the Prone Position
The area of aesthesia-induced atelectasis is much larger in the obese compared with the non-obese, but there may also be more airway closure and impaired matching of ventilation and lung blood flow.
When an anesthetized patient is turned to the prone position, dynamic compliance (Cdyn) decreases and peak airway pressure increases unless the abdomen hangs freely to prevent the abdominal viscera from compromising the diaphragm movement. Although the Wilson frame is designed to allow the abdomen to hang, it partially compresses the anterior abdominal wall and therefore does not allow the abdomen to hang completely, especially in obese patients.
This in turn increases peak airway pressure and decreases Cdyn, oxygenation. This study aimed to investigate the effects of a prolonged I:E ratio (i.e., 1:1) compared with the conventional I:E ratio of 1:2 on respiratory mechanics and hemodynamics during spine surgery in the prone position in obese patients.
We hypothesized that, compared with an I:E ratio of 1:2, a ratio of 1:1 improve oxygenation without hemodynamic instability .
Study Overview
Status
Conditions
Intervention / Treatment
Detailed Description
After written informed consent was obtained from all patients, 50 adult patients were enrolled in the study.
The patients met the following inclusion criteria: (1) body mass index (BMI, weight in kilograms divided by the square of height in metres) > 25 kg/m2; (2) American Society of Anesthesiology (ASA) physical status classification grade I or II (BMI by itself was not used as the basis for the ASA classification); (3) aged 20 - 65 years; and (4) scheduled for elective spine surgery in prone position.
Exclusion Criteria:
- Patients who have severe pulmonary disease:
history of chronic obstructive pulmonary disease (COPD), asthma, or pneumothorax. Patients with haemodynamic instability, hypovolaemia, bronchopleural fistula, The enrolled patients were randomly allocated according to a predetermined allocation sequence to receive an I:E ratio of either 1:1 (group 1:1) or 1:2 (group 1:2).
The allocation sequence with no blocking was generated in an Internet website Standard monitoring techniques, including electrocardiography, pulse oximetry, and noninvasive arterial blood pressure measurement, are applied upon arrival at the operating room.
Anesthesia was induced with intravenous propofol 1.5 mg_kg-1 and rocuronium 0.8 mg_kg-1 was administered intravenously.
After tracheal intubation, volume-controlled ventilation was initiated with an I:E ratio of 1:2 or 1:1, no positive end-expiratory pressure, and a tidal volume of 10 mL per ideal body weight (kg). A respiratory rate was adjusted in order to end-tidal carbon dioxide (EtCO2) of 33 - 36 mmHg during surgery. Anesthesia was maintained with an end-tidal concentration of 2-2.5 vol% sevoflurane in 40% oxygen/air. The bispectral index score was monitored continuously in order to maintain an adequate anesthetic depth and was targeted at a range of 40-60 during surgery.
Radial artery cannulation was conducted for monitoring continuous arterial blood pressure and blood sampling.
Respiratory, hemodynamic, and arterial blood gas data were assessed and recorded at three time points: ten minutes after tracheal intubation in the supine position (T1), 30 min after prone positioning (T2), 90 min after prone positioning(T3). Respiratory data consisted of peak airway pressure, plateau airway pressure, mean airway pressure, static compliance, EtCO2, respiratory rate, and minute volume. Arterial pH, arterial oxygen tension (PaO2), arterial carbon dioxide tension (PaCO2), and lactate level were obtained from arterial blood gas analysis.
Study Type
Enrollment (Actual)
Phase
- Not Applicable
Contacts and Locations
Study Locations
-
-
-
Incheon, Korea, Republic of, 22241
- Kyung Cheon Lee
-
-
Participation Criteria
Eligibility Criteria
Ages Eligible for Study
Accepts Healthy Volunteers
Genders Eligible for Study
Description
Inclusion Criteria:
- ASA I-II adult patients scheduled for spine surgery under general anesthesia.
- patient age : greater than 20 years and less than 65years
- Body Mass Index(BMI) >25 kg/m2
Exclusion Criteria:
- Patients who have severe pulmonary disease:
history of chronic obstructive pulmonary disease (COPD), asthma, or pneumothorax. Patients with haemodynamic instability, hypovolaemia, bronchopleural fistula, history of cardiopulmonary disease, or previous lung surgery are excluded.
Study Plan
How is the study designed?
Design Details
- Primary Purpose: Prevention
- Allocation: Randomized
- Interventional Model: Parallel Assignment
- Masking: None (Open Label)
Arms and Interventions
Participant Group / Arm |
Intervention / Treatment |
---|---|
Experimental: IE ratio 1:1
Set an I(inspiration):E(expiration) ratio1:1 in the mechanical ventilator during spine surgery in the prone position in obese patients.
|
Set an I:E ratio1:1 in the mechanical ventilator during spine surgery in the prone position in obese patients.
Other Names:
|
Active Comparator: IE ratio 1:2
Set an I(inspiration):E(expiration) ratio1:2 in the mechanical ventilator during spine surgery in the prone position in obese patients.
|
Set an I:E ratio1:2 in the mechanical ventilator during spine surgery in the prone position in obese patients.
Other Names:
|
What is the study measuring?
Primary Outcome Measures
Outcome Measure |
Measure Description |
Time Frame |
---|---|---|
PaO2(Partial Pressure of Oxygen in Arterial Blood)
Time Frame: ten minutes after tracheal intubation to 90 min after prone position
|
ten minutes after tracheal intubation to 90 min after prone position
|
ten minutes after tracheal intubation to 90 min after prone position
|
Collaborators and Investigators
Investigators
- Study Chair: Kyung Cheon Lee, MD, Gachon University Gil Medical Center
Study record dates
Study Major Dates
Study Start (Actual)
Primary Completion (Actual)
Study Completion (Actual)
Study Registration Dates
First Submitted
First Submitted That Met QC Criteria
First Posted (Estimate)
Study Record Updates
Last Update Posted (Actual)
Last Update Submitted That Met QC Criteria
Last Verified
More Information
Terms related to this study
Additional Relevant MeSH Terms
Other Study ID Numbers
- PrIspSp
Plan for Individual participant data (IPD)
Plan to Share Individual Participant Data (IPD)?
This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.
Clinical Trials on Hypoxia
-
Western University, CanadaUnknownBrain Hypoxia IschemiaCanada
-
Yale UniversityTianjin Chest HospitalCompletedBrain Ischemia Hypoxia | Muscle; Ischemic | Muscle HypoxiaChina
-
Fliegerärztliches InstitutCompleted
-
University of Texas at AustinCompletedIntermittent HypoxiaUnited States
-
Owlet Baby Care, Inc.Completed
-
Robert L. OwensCompletedIntermittent HypoxiaUnited States
-
Montreal Heart InstituteUniversité de MontréalCompleted
-
United States Army Research Institute of Environmental...University of Puget SoundRecruiting
-
The University of Hong Kong-Shenzhen HospitalRecruiting
-
Sherief Abd-ElsalamRecruiting
Clinical Trials on IE ratio 1:1
-
Gangnam Severance HospitalCompletedBlood Loss, SurgicalKorea, Republic of
-
Yonsei UniversityCompletedObese Patients, One Lung VentilationKorea, Republic of
-
Samsung Medical CenterCompletedLung Cancer | One Lung Ventilation | Gas Exchange | Inverse-ratio VentilationKorea, Republic of
-
Samsung Medical CenterCompletedUterine Myoma | Ovarian Cyst | Laparoscopic Gynecologic SurgeryKorea, Republic of
-
The University of Texas Health Science Center,...National Heart, Lung, and Blood Institute (NHLBI); United States Department... and other collaboratorsCompleted
-
Yonsei UniversityCompletedGeneral Anesthesia Using Endotracheal IntubationKorea, Republic of
-
VA Office of Research and DevelopmentRecruiting
-
Centre Hospitalier Universitaire de NiceRecruiting
-
Seoul National University HospitalCompletedProstatic Neoplasm | Urinary Bladder NeoplasmKorea, Republic of
-
Assistance Publique - Hôpitaux de ParisINSERM CESP1018Completed