The Influence of a Bupivacaine Digital Nerve Block Using Rev G.

Study Overview
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Brief Summary
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The investigators are proposing to continue investigation to improve the accuracy of the SpHb (continuous hemoglobin monitoring device) by administering an intermediate acting digital nerve block in the finger connected to the SpHb, specifically bupivacaine 0.25% in patients undergoing spine surgery. Bupivacaine is FDA approved and in routine use.

Detailed Description
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Patients undergoing spine surgery will be randomized to receive (or not) the bupivacaine digital block on the finger attached to the new limited release version of the hemoglobin sensor, RevG. The SpHb reading will be compared to a blood hemoglobin level analyzed in the UCSF Clinical Laboratories.

Official Title
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The Influence of a Bupivacaine Digital Nerve Block With the New Continuous Sensor (Rev G) on the Accuracy of SpHb Monitoring.

Conditions
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Patients Undergoing Spine Surgery

Intervention / Treatment
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* Other: intermediate-acting digital nerve block


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Male or female 18 years of age or older American Society of Anesthesiologists classification 1, 2 or 3 Scheduled to undergo spine or hip surgery Exclusion Criteria: Pregnant or nursing Patients who in the study investigators clinical judgement would not be suitable

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 85 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: Diagnostic
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: bupivacaine digital nerve block<br>Patients undergoing spine surgery will have a 50/50 chance of being randomized to receive a bupivacaine 0.25% (2 milliliters total) intermediate-acting digital nerve block. | Other: intermediate-acting digital nerve block<br>* non-therapeutic Bupivacaine digital nerve block to assess effect on accuracy of diagnostic readings<br>|
| No Intervention: No bupivacaine digital nerve block<br>Patients undergoing spine surgery will have a 50/50 chance of being randomized to not receive a bupivacaine 0.25% (2 milliliters total) intermediate-acting digital nerve block. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| SpHb (continuous hemoglobin monitor reading) minus tHb (clinical laboratory determined hemoglobin value). | Use of a longer acting local anesthetic (bupivacaine) for the digital nerve block will result in SpHb (the non-invasive hemoglobin device) being sufficiently accurate for blood transfusion decisions(≤ 1.0 g/dL difference) To assess if using an intermediate-acting digital nerve block will improve the accuracy of the SpHb readings when compared to a blood hemoglobin level analyzed in the UCSF Clinical Laboratories intermittently during the patient's surgery. | Intermittent (about hourly) hemoglobin checks throughout the surgery. | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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SpHb; hemoglobin monitoring;bupivacaine digital nerve block