Peripheral Nerve Blocks for Above-the-knee Amputations

Study Overview
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Brief Summary
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Surgery performed with nerve blocks and sedation may be safer and provide better pain control compared to general anesthesia and opioid therapy in high-risk patient populations such as elderly and troubled with peripheral vascular disease, diabetes, hypertension, coronary artery disease, and chronic obstructive pulmonary disease (COPD).

Detailed Description
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Avoidance of general anesthesia in certain high-risk patient populations may have additional benefits beyond improved postoperative pain scores and analgesic consumption. The primary objective of this research will be to evaluate the ability of the femoral, sciatic, lateral femoral cutaneous nerve (LFCN), and obturator blocks to provide surgical anesthesia.

Official Title
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Peripheral Nerve Blocks for Upper Leg Amputations

Conditions
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Peripheral Vascular Diseases, Hyperglycaemia (Diabetic), Hypertension, Coronary Artery Disease, Pulmonary Disease, Chronic Obstructive

Intervention / Treatment
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* Procedure: Peripheral nerve block
* Drug: Intravenous Sedatives
* Procedure: Lateral femoral cutaneous nerve blocks
* Procedure: Obturator nerve blocks


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients undergoing above-the-knee amputation or knee disarticulation Ability to understand and provide informed consent Exclusion Criteria: Patient refusal or inability to provide informed consent True allergy, not sensitivity, to any of the following substances: - Local anesthetics - Propofol or other sedative agents - General anesthetic agents Pregnancy Severe hepatic impairment Evidence of infection at or near the proposed needle insertion site Any sensorimotor deficit, whether acute or chronic, as determined by the PI Chronic use of opioid medication BMI ≥ 35

Ages Eligible for Study
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Minimum Age: 18 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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Design Details

Primary Purpose: Basic Science
Intervention Model: Single Group Assignment
Interventional Model Description: Pilot clinical trial with a single arm
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Peripheral nerve block<br>Prospectively evaluate peripheral nerve blocks as a primary anesthetic in the setting of above-the-knee amputations. All enrollees will be administered Intravenous sedatives using propofol or dexmedetomidine and have ultrasound-guided femoral and sciatic nerve blocks placed per current practice at research site. Single-injection obturator nerve blocks and lateral femoral cutaneous nerve blocks will also be performed. | Procedure: Peripheral nerve block<br>* All enrollees will have ultrasound-guided femoral and sciatic nerve blocks placed per current practice at research site. Single-injection obturator and lateral femoral cutaneous nerve blocks will also be performed.<br>Drug: Intravenous Sedatives<br>* Intravenous sedation using propofol or dexmedetomidine will be administered.<br>* Other names: Propofol or Dexmedetomidine;Procedure: Lateral femoral cutaneous nerve blocks<br>* After administration of intravenous sedation, lateral femoral cutaneous and obturator nerve blocks (in addition to the femoral and sciatic catheters) will be performed under ultrasound guidance.<br>Procedure: Obturator nerve blocks<br>* After administration of intravenous sedation, lateral femoral cutaneous and obturator nerve blocks (in addition to the femoral and sciatic catheters) will be performed under ultrasound guidance.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Chi-squared tests of peripheral nerve block success as a primary anesthetic | Differences in block success percentages analyzed between study participants. | Changes from baseline through 30 days post-operative | 
| Analysis of pain scores | Numerical rating scale pain scores (0-10) will be obtained from patients upon arrival and recorded hourly until discharge. Patients will be called or visited 24-48 hours post procedure to inquire about patient satisfaction. Differences in study participant pain scores will be examined through t-tests. P < 0.05 will be considered statistically significant. | Changes from baseline through 48 hours post procedure. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Mortality | The medical record will be reviewed to assess 30-day mortality. | Changes from baseline through 30 days post-operative |