Lipid Emulsion for Reversal of Spinal Anesthesia in Ambulatory Surgery

Not Applicable

Recruiting

• Conditions: Spinal Anaesthesia; Spinal Anesthesia Evaluation; Ambulatory Surgery
• Interventions: Drug: Intravenous Lipid Emulsion 20%; Drug: Control (placebo) group

• Registration Number: NCT06988982
• Lead Sponsor: Zagazig University

Brief Summary

Ambulatory surgery places high demands on anesthetic technique. rapid onset and offset of anesthesia, rapid recovery of protective reflexes, mobility and micturition, are required. Since the inception of ambulatory surgery, the favored anesthetic technique has been general anesthesia with short-acting drugs. Concerns about the time to perform spinal anesthesia and the risks of prolonged motor block and urinary retention have limited its use.

Alpha-blockers, lavage fluids for epidural space, insulin, and intravenous lipid emulsions, are still being discussed to shorten and reverse adverse effect of different LAs used for spinal anaesthesia, hence we will evaluate the effectiveness of intravenous lipid emulsion for reversing the neural blockade of spinal anaesthesia in patients undergoing ambulatory surgery.

Detailed Description

An increasing number of ambulatory surgical patients is challenging the currently used anaesthesia methods, reliable surgical anaesthesia should be quick, with rapid recovery and minimal side effects. Spinal anaesthesia (SA) is an easy and reliable technique that has grown in popularity for inpatient surgery, but its use in ambulatory surgery has been limited due to several factors including the prolonged neurological block with long-acting local anaesthetics (LA), delayed ambulation, risk of urinary retention and pain after block regression therefore delaying patient discharge. On the other hand, general anaesthesia with short-acting drugs grants rapid recovery enabling the early discharge. While recovery after spinal anaesthesia has been recently improved by lowering the dose of the commonly used long-acting local anaesthetics such as bupivacaine, discharge times are still prolonged compared to general anaesthesia.

Intravenous lipid emulsions (ILEs) were originally developed as a part of parenteral nutrition for critically ill patients, dating back to the 1960s. Over the last ten years, there has been rising interest in ILEs in clinical toxicology beyond its established role in the treatment of acute intoxication with local anaesthetics (LAST). The use of ILEs for the treatment of lipophilic drug toxicity is increasing nowadays with several studies reported alleviation of intractable cardiovascular collapse induced by toxic doses of these non-local anaesthetic drugs including calcium channel blockers (verapamil), tricyclic antidepressants (amitriptyline) and beta-blockers. In addition, Complications following intrathecal administration of bupivacaine have been reported to be successfully managed with intravenous administration of lipid emulsion.

While the precise mechanism by which ILEs exerts its effect remains unknown, the leading theory is that the ILEs intravascular action entails creating a concentration gradient which favours LA redistribution to the extracellular space. Lipid vesicles then encapsulate LA creating lipid sinks and the formation of this "trap" removes the toxins from the various tissues and organs, reducing their bioavailability and the sequestration mechanism where LA is rapidly redistributed by "lipid shuttles" to sites of metabolism (liver), storage (adipose tissue) or elimination (kidney). Alternative theories include reduced binding of local anaesthetics to sodium transport channels, direct promotion of sodium channel function recovery, and replenishing ATP stores from increased uptake of fatty acids by mitochondria.

Considering the few published reports supporting the effectiveness of ILEs in reversing the primary nervous system effects of regional anaesthesia such as total or high spinal anaesthesia, prolonged neural blockade, and reverse phrenic nerve palsy secondary to a brachial plexus block with the well-known favourable safety profile of ILEs. We hypothesized that ILEs could be an attractive effective option to reverse the sensory and motor actions of intrathecal bupivacaine thus accelerating the neurological recovery after spinal anaesthesia which could avert the delayed hospital discharge and facilitate the use of SA for ambulatory surgeries.

Study Timeline

• Status Verified: 2025-05
• Study First Submitted: 2025-05-17
• Study First Submitted QC: 2025-05-17
• Last Update Submitted: 2025-05-17
• Study First Posted: 2025-05-25
• Last Update Posted: 2025-05-25
• Study Start: 2025-06-01
• Primary Completion: 2025-12-30
• Study Completion: 2026-01-01

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 42

Inclusion Criteria

• Patient acceptance.
• Cooperative patient
• Age 21-70 years old.
• BMI ≤ 35 kg/m2
• ASA I - II.
• Elective ambulatory surgery under spinal anesthesia (general surgery, urology, gynecology, orthopedic surgery).

Exclusion Criteria

• History of allergy to the LA agents used in this study,
• Skin lesion at needle insertion site,
• Those with bleeding disorders, sepsis, liver disease and psychiatric disorders
• History of cognitive dysfunction or mental illness

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Group ILE (Intravenous lipid emulsion group)	Intravenous Lipid Emulsion 20%	patients will receive 1.5 ml/kg bolus of intravenous lipid emulsion 20 % followed by 0.25 ml/kg/hour infusion over 30 minutes at the end of surgery
Group C (control group)	Control (placebo) group	patients will received equal volume of normal saline at the end of surgery

Primary Outcome Measures

Name	Time	Method
Time for complete sensory and motor regression (min)	6 hours after surgery	Time for complete sensory regression (min) (primary outcome) to be calculated from the time of ILEs administration (T0) until full sensation at S1 dermatomal level achieved Time for complete motor regression (min) (primary outcome) to be calculated from time of ILEs administration (T0) until Bromage score will be zero.

Secondary Outcome Measures

Name	Time	Method
Time for two segment sensory regression (min)	6 hours after surgery	the time for regression by two dermatomes compared with the dermatomal level assessed at finishing ILEs infusion (T0)
Time to walk (min) without or with minimal assistance	6 hours after surgery	the time from the ILE administration time (T0) till the patients first stand and walk.
Time to Void (min)	6 hours after surgery	the time from the ILE administration time (T0) till the patients first urinate.
Time to be home-ready (min)	6 hours after surgery	the time from the ILE administration time (T0) till the patients are ready for home discharge as defined by the modified post anaesthesia discharge scoring system.
Time to actual hospital discharge (min)	24 hours after surgery	the period from the end of the surgery till the patients actually leaves the hospital.
Heart rate (HR), and arterial blood pressure (MAP)	6 hours after surgery	Heart rate (HR), and arterial blood pressure (MAP), will be recorded immediately before and after the ILEs administration, at PACU admission and then every 15 min till the PACU discharge.
Numerical rating scale (NRS)	24 hours after surgery	Numerical rating scale (NRS) will be postoperatively assessed and recorded at PACU admission, PACU discharge to phase II recovery, in phase II recovery room, before actual hospital discharge and at 24 h.
Time to first rescue analgesia (min)	24 hours after surgery	the time between ILE administration (T0) to the time patients make their first request for pain relief and NRS ≥ 3.
Total dose of rescue analgesia (diclofenac sodium)	24 hours after surgery	Total dose of rescue analgesia (diclofenac sodium), that will be consumed in the first 24 hours postoperatively.
Patient satisfaction	2 weeks after surgery	Patient satisfaction using a 3-point Likert scale (3=satisfied, 2= neutral, 1=dissatisfied).
Postoperative Complications.	2 weeks after surgery	Postoperative complications will be evaluated including nausea and vomiting, the use of antiemetics, inability to void within 4h after surgery, post-dural puncture headache, transient neurological symptoms (TNS) and lipid emulsions related adverse effects such as hypotension, bradycardia, fever, dyspnea, allergic reaction, increased risk of infection, and fat overload syndrome.; The day after surgery and for one week, all patients will be contacted by telephone and asked about pain and analgesic use, low back pain, headache and transient neurological symptoms. One and two weeks after surgery, patients will be evaluated by the surgical team and the existence of any complications will be recorded.

Trial Locations

Locations (1)

Zagazig University Hospitals; 🇪🇬 Zagazig, Al Sharqia, Egypt