The Application of Ultrasonic Measurement of Optic Nerve Sheath Diameter in Liposuction Surgery

NCT ID: NCT06685952

Last Updated: 2025-09-30

Basic Information

• Recruitment Status: COMPLETED
• Total Enrollment: 55 participants
• Study Classification: OBSERVATIONAL
• Study Start Date: 2024-11-19
• Study Completion Date: 2025-05-26

Brief Summary

The main purpose of this study is to investigate the effect of changes in Optic Nerve Sheath Diameter (ONSD) measured at different operating position during Liposuction Surgery.

Optic nerve sheath diameter (ONSD) has been shown to be a noninvasive indicator for monitoring intracranial pressure changes.

The use of anesthetic drugs will reduce the intracranial pressure. However, prone position and large fluid infusion can still lead to increased intracranial pressure.

The investigators hypothesized that during sedation and analgesia anesthesia, patients in prone position had higher ONSD.

Detailed Description

Liposuction is a common type of surgery in plastic surgery. In this type of surgery, the position is often changed from prone to supine. Different surgical positions, especially excessive flexion or rotation of the neck, can cause compression of the internal jugular vein, resulting in blocked cerebral venous return and resulting in increased intracranial pressure. Sedation and analgesia anesthesia are often used in liposuction surgery to provide the patient with an appropriate depth of anesthesia, preserve the patient's independent breathing, and can wake the patient during the operation to complete the position switch independently. Dexmedetomidine is a commonly used drug for sedation and analgesia anesthesia. Studies have reported that dexmedetomidine can be used to control intracranial pressure in special surgical positions by reducing cerebral metabolic rate, maintaining cerebral oxygen supply and demand balance, shrinking cerebral vessels and other functions.

Other studies have suggested that IOP increases during prone anesthesia, despite the effect of anesthetic drugs on lowering IOP. IOP, choroidal thickness, and optic nerve diameter also increased in normally awake patients in prone position. Optic nerve sheath diameter (ONSD) has been shown to be a noninvasive indicator of intracranial pressure changes and an independent factor of mortality, poor prognosis, and severity of traumatic brain injury. ONSD measurement is often used in laparoscopic surgery under general anesthesia to observe the effect of elevated CO2 in pneumoperitoneum on IOP. The changes of intracranial pressure were evaluated by ONSD when the head was low and the feet were high.

At present, there are no studies to observe the change of ONSD at different positions during Liposuction Surgery with sedation and analgesia.

The investigators hypothesized that during sedation and analgesia anesthesia, patients in prone position had higher ONSD.

This is an observational study. They were divided into two groups according to the operation, prone group and supine group.T0 awake, T1 30min after sedation and analgesia, T2 30 minutes after T1， T3 end of the operation. Record Optic nerve sheath diameter (ONSD), carotid artery flow rate, Bispectral index (BIS), liposuction swelling fluid input, infusion volume, end-expiratory carbon dioxide, mean arterial pressure, heart rate, peripheral oxygen saturation, body temperature and respiratory rate. Statistically significant differences were assessed.

The incidence of headache, nausea, vomiting and delirium were observed within 24 hours after operation.

Conditions

Optic Nerve Sheath Diameter

Study Design

• Observational Model Type: COHORT
• Study Time Perspective: PROSPECTIVE

Study Groups

Prone position group

Sedation and analgesia anesthesia will be administered after the prone position.

All patients will receive standardized sedation and analgesia anesthesia with 1ug/kg sufentanil，1ug/kg/h dexmedetomidine，1mg/h midazolam，0.05-0.1ug/kg/min remifentanil. And adjust the drug speed according to the patient's respiratory rate, BIS changes.

Optic nerve sheath diameter (ONSD), carotid artery flow rate, Bispectral index (BIS), liposuction swelling fluid input, infusion volume, end-expiratory carbon dioxide, mean arterial pressure, heart rate, peripheral oxygen saturation, body temperature and respiratory rate will be measured at four time points respectively.

No interventions assigned to this group

Supine group

Sedation and analgesia anesthesia will be administered after the supine position.

All patients will receive standardized sedation and analgesia anesthesia with 1ug/kg sufentanil，1ug/kg/h dexmedetomidine，1mg/h midazolam，0.05-0.1ug/kg/min remifentanil. And adjust the drug speed according to the patient's respiratory rate, BIS changes.

Optic nerve sheath diameter (ONSD), carotid artery flow rate, Bispectral index (BIS), liposuction swelling fluid input, infusion volume, end-expiratory carbon dioxide, mean arterial pressure, heart rate, peripheral oxygen saturation, body temperature and respiratory rate will be measured at four time points respectively.

No interventions assigned to this group

Eligibility Criteria

Inclusion Criteria

• Patients aged 18-50 years, undergoing liposuction surgery.
• American Society of Anesthesiologists (ASA) physical status Ⅰ and Ⅱ.
• Voluntary participation and signed an informed consent form.

Exclusion Criteria

• Uncontrolled hypertension, diabetes.
• High nearsightedness or farsightedness, recent eye surgery, and other conditions in which ONSD cannot be measured.
• Moderate to severe obstructive sleep apnea syndrome was present before surgery.
• History of severe mental or neurological diseases, drug or psychotropic drug abuse.
• Cognitive dysfunction or inability to communicate.

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 50 Years
• Eligible Sex: FEMALE
• Accepts Healthy Volunteers: No

Sponsors

The Plastic Surgery Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College

OTHER

Sponsor Role: lead

Responsible Party

Xu Wenli

Attending physician

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Dong Yang

Role: STUDY_CHAIR

Plastic Surgery Hospital, Chinese Academy of Medical Sciences and PekingUnion Medical College

Locations

Xu Wenli

Beijing, Beijing Municipality, China

Countries

China

Other Identifiers

ZX2024310

Identifier Type: -

Identifier Source: org_study_id