Optimal Anesthesia for Morbidly Obese Patients

NCT04395248 | Completed Phase 4 DMC

• 1 other identifier: N202002076
• Study Type: interventional
• Target: 80
• Locations: 1 country
• Sites: 1

Brief Summary

Obese patients have a higher risk of anesthesia compared to the non-obese, including difficult intubation, rapid desaturation, difficult vascular access, and delayed recovery from anesthesia. This study aims to investigate the optimal anesthesia strategy for morbidly obese patients undergoing bariatric surgery in airway management, preoxygenation, arterial cannulation, and type of volatile anesthetic with M-Entropy guidance. The investigators will conduct a two-year clinical trial using permuted block randomization to evaluate multiple outcomes in patients undergoing laparoscopic sleeve gastrectomy (LSG) at Shuang Ho Hospital, Taipei Medical University. Particularly, the investigators will explore the role of ultrasound, an easily accessible modality for anesthesiologists, in examining upper airway anatomy and guiding arterial cannulation. The investigators will also assess the effectiveness of high-flow nasal cannula as a preoxygenation tool in preventing desaturation.

Conditions

Obesity; Anesthesia

Keywords

Obesity; Anesthesia; Enhanced recovery after surgery; Difficult intubation; Preoxygenation; Depth of anesthesia; High-flow nasal cannula

Outcome Measures

Primary Outcomes (4)

• Occurrence of difficult laryngoscopy

  The laryngoscopic view will be graded according to Cormack and Lehane's classification with external laryngeal pressure applied. Grade 1: Most of the glottis is visible; Grade 2: At best almost half of the glottis is seen, at worst only the posterior tip of the arytenoids is seen; Grade 3: Only the epiglottis is visible; Grade 4: No laryngeal structures are visible.

  One day before surgery to tracheal intubation

• First-attempt success rate for arterial cannulation

  An attempt is defined as a new penetration of the skin with the needle, followed by an unlimited number of subcutaneous needle redirections.

  Before induction of anesthesia

• PaO2 after preoxygenation

  Arterial blood gas will be analyzed promptly after 5-min preoxygenation.

  Before induction of anesthesia

• Time to spontaneous eye opening

  The interval from discontinuation of volatile anesthetics to spontaneous eye opening

  The period from discontinuation of volatile anesthetics to spontaneous eye opening, an average of 15 minutes

Secondary Outcomes (15)

• First-attempt success rate for intubation

  After induction of anesthesia

• Time to successful intubation

  After induction of anesthesia

• Time to successful arterial catheterization

  Before induction of anesthesia

• Number of attempts for arterial cannulation

  Before induction of anesthesia

• Number of sites and catheters used for arterial cannulation

  Before induction of anesthesia

Study Arms (4)

Risk factors of difficult intubation

ACTIVE COMPARATOR

Appearance anpalpationpalpationpalpationd ultrasound features for predicting difficult laryngoscopy intubation

Procedure: Exploring potential risk factors of difficult intubation using ultrasound

Radial artery cannulation using ultrasound or blind palpation

ACTIVE COMPARATOR

In the ultrasound group, a linear vascular probe in the frequencies 5 to 13 MHz (GE 12L-RS, GE Healthcare, Chicago, IL, USA) of portable ultrasound device (LOGIQTM, GE Healthcare, Chicago, IL, USA) will be applied to the skin to localize the radial artery and a 20-gauge catheter will be inserted distal to the transducer and directed according to the ultrasound image.

Procedure: Radial artery catheterization using ultrasound guidance or blind palpation

Preoxygenation using high-flow nasal cannula or facemask

ACTIVE COMPARATOR

In the HFNC group, preoxygenation will be performed using HFNC (Optiflow™, Fisher \& Paykel Healthcare, Auckland, NZ), nasal prongs set at 30 L/min flow of heated and humidified 100% oxygen. In the facemask group, patients will breath spontaneously with an anesthetic facemask and 100% oxygen 15 L/min. Gas flow for HFNC or facemask can be adjusted depending on patients' tolerance. During laryngoscopy intubation, HFNC will be left in place with the nasal flow escalated to 50 L/min of 100% oxygen in order to achieve apneic oxygenation. In the facemask group, the facemask will be removed when apnea occurs.

Device: Comparing the effectiveness of preoxygenation between high-flow nasal cannula and facemask

Type of volatile anesthetics and M-Entropy guidance

ACTIVE COMPARATOR

Patients will be randomized by a computer-generated list into one of the four groups, desflurane with usual care (N=20), desflurane with M-Entropy guidance (N=20), sevoflurane with usual care (N=20), and sevoflurane with M-Entropy guidance (N=20).

Drug: Type of volatile anesthetics and M-Entropy guidance of anesthesia depth

Interventions

Exploring potential risk factors of difficult intubation using ultrasound PROCEDURE

Before surgery, ultrasound will be used to assess pretracheal soft tissue depth and height and width of tongue base. The distance from the skin to the anterior aspect of the trachea will be measured at three levels: vocal cords, thyroid isthmus, and suprasternal notch. With the patient in a seated position, the convex transducer of a portable ultrasound device (LOGIQTM, GE Healthcare, Chicago, IL, USA) will be introduced to the skin of the neck in the submental region coronally, immediately cephalad to the body of the hyoid bone, and then in the area between the hyoid bone and the symphysis of the mandible. Maximal width of tongue base, tongue base height, and maximal height of mid-tongue will be measured. The laryngoscopy intubation will be performed using a size-3 or -4 Macintosh (Rüsch Inc., Duluth, GA, USA) blade and a styletted endotracheal tube. The laryngoscopic view will be graded according to Cormack and Lehane's classification with external laryngeal pressure applied.

Risk factors of difficult intubation

Radial artery catheterization using ultrasound guidance or blind palpation PROCEDURE

For all patients, the wrist will be extended and taped to a board to maintain wrist extension. All patients will receive local skin anesthesia at the anticipated puncture site. All radial artery catheterizations will be performed by anesthesiology residents with similar levels of experience in both blind-palpation and ultrasound-guided radial arterial catheterization. In the ultrasound group, a linear vascular probe of portable ultrasound device (LOGIQTM, GE Healthcare, Chicago, IL, USA) will be applied to the skin to localize the radial artery and a 20-gauge catheter will be inserted distal to the transducer and directed according to the ultrasound image. In the palpation group, the radial artery will be identified by palpation, and the cannula will be directed by continuous or intermittent palpation of arterial pulsation. An attempt is defined as a new penetration of the skin with the needle, followed by an unlimited number of subcutaneous needle redirections.

Radial artery cannulation using ultrasound or blind palpation

Comparing the effectiveness of preoxygenation between high-flow nasal cannula and facemask DEVICE

In the HFNC group, preoxygenation will be performed using HFNC (Optiflow™, Fisher \& Paykel Healthcare, Auckland, NZ), nasal prongs set at 30 L/min flow of heated and humidified 100% oxygen. In the facemask group, patients will breath spontaneously with an anesthetic facemask and 100% oxygen 15 L/min. Gas flow for HFNC or facemask can be adjusted depending on patients' tolerance. During laryngoscopy intubation, HFNC will be left in place with the nasal flow escalated to 50 L/min of 100% oxygen in order to achieve apneic oxygenation. In the facemask group, the facemask will be removed when apnea occurs. After tracheal intubation, correct placement of the endotracheal tube will be confirmed by capnography and the nasal prongs of the HFNC group will be removed.

Preoxygenation using high-flow nasal cannula or facemask

Type of volatile anesthetics and M-Entropy guidance of anesthesia depth DRUG

At the operating room, a M-Entropy™ sensor and S/5™ module (GE Healthcare, Helsinki, Finland) will be applied to all patients' forehead before induction of anesthesia according to the manufacturer's recommendations. Patients will be randomized to Sevoflurane or Desflurane as the single volatile anesthetics for general anesthesia. Besides, patients will be randomized to M-Entropy group or controls. In the M-Entropy group, dosage of volatile anesthetics will be adjusted to achieve the Response and State Entropy value between 40 and 60 from the start of anesthesia to the end of surgery. In the usual care group, dosage of volatile anesthetics will be titrated according to clinical judgment. M-Entropy monitoring will be continued in the usual care group, but the Entropy number and EEG waveform will be concealed from the anesthetist in charge.

Type of volatile anesthetics and M-Entropy guidance

Eligibility Criteria

• Age: 20 Years - 65 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Age 20 to 65 years
• BMI ≥ 30 kg/m2
• Undergoing laparoscopic sleeve gastrectomy at Shuang-Ho Hospital, Taiwan

You may not qualify if:

• Severe cardiopulmonary disease
• Psychiatric disorder
• History of head and neck surgery or radiation therapy
• Cervical spine injury
• Renal insufficiency (estimated creatinine clearance \< 60 ml/min)
• SpO2 \< 90% in room air
• Hemodynamic instability
• Preexisting arterial catheterization during the same visit within 7 days
• Patient refusal

Sponsors & Collaborators

• Taipei Medical University Shuang Ho Hospital: lead
• Ministry of Science and Technology, Taiwan: collaborator

Study Sites (1)

Department of Anesthesiology, Shuang-Ho Hospital, Taipei Medical University

New Taipei City, 23561, Taiwan

Location

Related Publications (1)

• Wu YM, Su YH, Huang SY, Wang CW, Shen SC, Chen JT, Lo PH, Cherng YG, Wu HL, Tai YH. Morphometric and ultrasonographic determinants of difficult laryngoscopy in obese patients: A prospective observational study. J Chin Med Assoc. 2022 May 1;85(5):571-577. doi: 10.1097/JCMA.0000000000000721. Epub 2022 May 2.

  PMID: 35385418 DERIVED

MeSH Terms

Conditions

Obesity

Condition Hierarchy (Ancestors)

Overweight; Overnutrition; Nutrition Disorders; Nutritional and Metabolic Diseases; Body Weight; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Study Officials

• Ying-Hsuan Tai, M.D., M.Sc.

  Department of Anesthesiolgy, Shuang-Ho Hospital, Taipei Medical University, Taiwan

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: phase 4
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: FACTORIAL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator

Study Record Dates

• First Submitted: May 11, 2020
• First Posted: May 20, 2020
• Study Start: May 26, 2020
• Primary Completion: August 31, 2021
• Study Completion: August 31, 2021
• Last Updated: May 18, 2022

Record last verified: 2022-05

Data Sharing

• IPD Sharing: Will not share

Locations

TW (1)