Minimum Effective Intrathecal Dose of Local Anaesthetic With Fentanyl for Fractured Neck of Femur(Dose Finding Study).

Study Overview
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Brief Summary
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Fractured neck of femur (FNF) is a common cause of admission to hospital in elderly patients with multiple comorbidities. Anaesthetic management of this patient group is extremely challenging.Neuraxial anaesthesia with minimum doses of local anaesthetic agents administered via a spinal catheter leads to better cardiovascular stability.The minimum dose of local anaesthetic with intrathecal fentanyl was not established yet.We propose to study and determine the initial minimum local anaesthetic dose (MLAD) of 0.5% bupivacaine with 20 mcg of fentanyl administered via a spinal catheter to achieve a sensory block up to T10 for the operative fixation of FNF.We will use a previously well established Dixon and Massey up-and-down method to calculate initial MLAD in this prospective, observational trial. Objectives: We would like to determine the initial MLAD of 0.5% bupivacaine with 20mcg of fentanyl administered via a spinal catheter required to achieve a sensory block up to T10 on the side of FNF. Outcomes Primary outcome: Initial MLAD of 0.5% bupivacaine with 20mcg of fentanyl required for a sensory block up to T10 on the side of FNF. Secondary outcomes: Total dose of 0.5% bupivacaine with 20mcg of fentanyl required for the operative fixation of fractured neck of femur. The effect on haemodynamic variables (blood pressure, heart rate). Incidence of side effects The length of postoperative analgesia (the time from the last dose of local anaesthetic administered intrathecally to VAS>3). The time to first rescue analgesic requirement Study Design Prospective, observational trial. Study Size Based on the previously well established Dixon and Massey up-and-down method(10), we will recruit patients until a successful spinal block has been achieved in six consecutive patients who received a specific dose. This is the requirement to calculate the initial MLAD.

Official Title
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Determination of the Initial Minimum Effective Dose of 0.5% Bupivacaine With 20mcg of Fentanyl Via a Spinal Catheter for Operative Fixation of Fractured Neck of Femur.

Conditions
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Minimum Effective Dose of Local Anaesthetic With Fentanyl

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: fractured neck of femur Above 60 years American Society of Anesthetists(ASA) I to III Exclusion Criteria: Patient refusal Outside Age Range Contraindications to spinal anaesthesia Head injury or other associated injuries Loss of consciousness and signs of acute coronary syndrome Mini-Mental Score < 25 (Appendix 2) Allergy to bupivacaine, lignocaine or fentanyl

Ages Eligible for Study
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Minimum Age: 60 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Bipolar hemiarthroplasty.<br>Group of patients who will stay in lateral position during whole surgery. | |
| Dynamic hip screw.<br>Group of patients who will be supine during surgery. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Initial MLAD of 0.5% bupivacaine with 20mcg of fentanyl required for a sensory block up to T10 on the side of FNF | A blinded observer will assess the dermatome level of sensory blockade with an ice-cold test (ethyl-chloride spray) bilaterally after the injection of the local anaesthetic. Block assessment will be performed every 5min up to 15 min after completion of the initial intrathecal injection. Sensory block up to T10=positive result Sensory block below T10=negative result. | 15min | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Total dose of 0.5% bupivacaine with 20mcg of fentanyl required for the operative fixation of fractured neck of femur | Initial dose and all top ups will be recorded and analysed in conjunction with the length of surgery and surgical procedure used to fix FNF. | Duration of surgery. | 
| The effect on haemodynamic variables (blood pressure, heart rate). | Noninvasive automated blood pressure and heart rate measurements will be recorded before the spinal anaesthesia (baseline) and every three minutes after the end of local anesthetic injection until the end of surgery.Hypotension is defined as a decrease of more than 20% from the baseline systolic arterial blood pressure (SAP). Severe hypotension is defined as a decrease in SAP more than 30% of baseline value. Hypotension will be treated with IV boluses of ephedrine 6 mg if the heart rate is below 60/minutes or phenylephrine 100 mcg if the heart rate is above 60/minutes.The number of hypotensive episodes, a total amount of vasopressor administered, and the i.v. fluid infused will be recorded as well as duration of anaesthesia. | Duration of surgery. | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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minimum effective dose of local anaesthetic, spinal catheter, fractured neck of femur, a step up, step down methodology