Impact of Dexamethasone on the Duration of Sensory and Motor Block Following Spinal Anesthesia

Not Applicable

Completed

• Conditions: Prolonged Sensory Block; Prolonged Motor Block; Spinal Anesthesia
• Interventions: Drug: Normal saline; Drug: Dexamethasone

• Registration Number: NCT03078062
• Lead Sponsor: Centre hospitalier de l'Université de Montréal (CHUM)

Brief Summary

The purpose of this study is to assess the effect of a single-dose of intravenous dexamethasone 8 mg on the duration of sensory and motor blockade following spinal anesthesia with isobaric bupivacaine.

The hypothesis of the study is that intravenous dexamethasone will significantly prolong (by more than 20 minutes) the duration of spinal anesthesia.

Detailed Description

Spinal anesthesia is commonly used for lower body surgery. The injection of local anesthetics in the lumbar intrathecal space allows the desensitization of the lower body by blocking sensory and motor nerve roots. In return, spinal anesthesia causes a sympathetic block which is associated with deleterious hemodynamic effects such as hypotension.

Using intravenous or intrathecal adjuvants to local anesthetics may prolong the duration of sensory and motor blockade following spinal anesthesia. Various intrathecal additives have been studied such as opioids, adrenalin, clonidine, dexmedetomidine, midazolam, ketamine, magnesium, ketorolac and neostigmine. Most of them failed to prolong the duration of spinal anesthesia and side-effects have restricted their use.

Dexamethasone is a potent corticosteroid with a half-life of 36 to 72 hours and an onset of action of 1 to 2 hours. The safety of single doses of intravenous dexamethasone is well documented. Dexamethasone is widely used in anesthesia to prevent nausea and vomiting and treat post-extubation sore throat and postoperative shivering. It is also increasingly used in orthopaedic surgery to reduce opioid needs without increasing the risks of infection, wound dehiscence and osteonecrosis. The use of dexamethasone in the perioperative period reduces postoperative edema allowing early mobilization and improved functional recovery.

Recent studies have demonstrated that both perineural and intrathecal administration of dexamethasone can prolong the duration of peripheral and spinal anesthesia. However, dexamethasone has not been approved by health authorities for these indications and thus, the safety of this practice remains controversial. A recent study has compared peripheral to intravenous administration of dexamethasone for interscalene blocks. This study demonstrated the equivalency of these regimens in increasing the analgesic duration of a single-shot interscalene block.

The impact of intravenous dexamethasone on the duration of spinal anesthesia remains unknown. This study will investigate the effect of a single-dose of dexamethasone 8 mg on the duration of the sensory and motor block following spinal anesthesia.

Sixty patients scheduled for lower body surgery under spinal anesthesia will be considered for this study.

After placement of standard non-invasive monitoring, spinal anesthesia will be performed in the sitting position using a 25 gauge (GA) pencil point needle (Whitacre, Pencan). After aspiration of cerebrospinal fluid (CSF), a dose of isobaric 0.5% bupivacaine 12 mg will be injected. The aspiration of CSF will be repeated at the end of the injection. While performing spinal anesthesia, an intravenous infusion of dexamethasone 8 mg or placebo will be initiated according to randomization.

Subsequently, the patient will be placed in supine position. Sensory block will be measured by loss of sensation to pinprick at 5, 10, 20 and 30 minutes following spinal anesthesia and then every 15 minutes until confirmation of regression by two dermatomes. Loss of sensation will be assessed every 30 minutes thereafter. Motor block will be assessed using the Bromage scale at the same frequency until full recovery.

Sedation will be allowed during the performance of the spinal anesthesia technique and surgery. In case of unsatisfactory quality of spinal anesthesia, general anesthesia will be performed.

At the end of surgery, patients will be transferred to the recovery room. Multimodal analgesia including celecoxib and acetaminophen will be administered. Pain will be assessed using a verbal numeric pain scale (VNPS) of 0 to 10, where 0 means "No pain" and 10 means "Worst pain imaginable". Intravenous hydromorphone will be administered when VNPS is superior to 3. Postoperative nausea and vomiting will be managed with intravenous ondansetron, dimenhydrinate and haloperidol.

Opioid intake, presence of side-effects and quality of sleep will be assessed during the first 24 hours following surgery.

Study Timeline

• Study First Submitted: 2017-03-03
• Study First Submitted QC: 2017-03-07
• Study First Posted: 2017-03-13
• Study Start: 2017-05-26
• Status Verified: 2017-10
• Primary Completion: 2017-10-26
• Study Completion: 2017-10-26
• Last Update Submitted: 2017-10-26
• Last Update Posted: 2017-10-27

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 60

Inclusion Criteria

• Patients undergoing lower body surgery under spinal anesthesia
• American Society of Anesthesiologists' physical status of 1 to 3

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Exclusion Criteria

• Contraindication to spinal anesthesia (coagulopathy, local infection at the site of injection)
• Pre-existing neuropathy or nerve block that could compromise study assessments
• Preoperative use of systemic corticosteroids
• Allergy or hypersensitivity to local anesthetics, dexamethasone or other drugs used in this study
• Patient refusal or inability to consent

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Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Normal Saline	Normal saline	During the performance of spinal anesthesia using isobaric 0.5% bupivacaine 12 mg, an intravenous infusion of 502 ml of Normal Saline will be initiated. The infusion will be administered over 5 -10 minutes. The study drug will be prepared by an independent assistant.
Dexamethasone	Dexamethasone	During the performance of spinal anesthesia using isobaric 0.5% bupivacaine 12 mg, an intravenous infusion of dexamethasone 8 mg (2 ml) will be initiated. The study drug will be administered over 5 -10 minutes diluted in a 500 ml bag of Normal Saline for a total volume of 502 ml. The study drug will be prepared by an independent assistant.

Primary Outcome Measures

Name	Time	Method
Regression of sensory block by 2 dermatomes	At regression of spinal anesthesia by 2 dermatomes, approximately 2 hours after surgery	Loss of pinprick sensation by Von Frey filaments from the injection of bupivacaine for spinal anesthesia until regression of the sensory block by two dermatomes from the peak sensory level

Secondary Outcome Measures

Name	Time	Method
Onset of sensory block	Up to 30 minutes following spinal anesthesia	Time from injection of bupivacaine for spinal anesthesia to reduction of sensitivity using loss of pinprick sensation
Onset of motor block	Up to 30 minutes following spinal anesthesia	Time from injection of bupivacaine for spinal anesthesia to reduction of lower limbs movement using the Bromage scale
Duration of motor block	At 5,10, 20 and 30 minutes following spinal anesthesia, then every 15 minutes until regression of 2 dermatomes and every 30 minutes thereafter until complete recovery, approximately 4 hours after surgery	Using the Bromage scale from the time of injection of bupivacaine for spinal anesthesia until complete recovery of motor block
Quality of motor block	Up to 30 minutes following spinal anesthesia	Maximal Bromage score
Surgeon's satisfaction towards spinal anesthesia	At the end of surgery, on the day of randomization	Unsatisfied or satisfied
Time to first analgesic request	From the end of surgery up to approximately six hours after surgery, on the day of randomization	First request by the patient for an analgesic or pain superior to 3 on a scale from 0 to 10; where 0 means "no pain at all" and 10 means "worst pain imaginable"
Opioid consumption	At recovery room discharge, approximately one hour after the end of surgery on the day of randomization and 24 hours following surgery	Total dose of opioids
Incidence of hypotension	From injection of bupivacaine for spinal anesthesia to 24 hours after surgery	Systolic blood pressure lower than 90 mm Hg
Incidence of bradycardia	From injection of bupivacaine for spinal anesthesia to 24 hours after surgery	Heart rate slower than 50 beats per minute
Incidence of nausea	From injection of bupivacaine for spinal anesthesia to 24 hours after surgery	Any episode of nausea reported by the patient or nursing team
Incidence of vomiting	From injection of bupivacaine for spinal anesthesia to 24 hours after surgery	Any episode of retching or vomiting reported by the patient or nursing team
Incidence of urinary retention	From injection of bupivacaine for spinal anesthesia to 24 hours after surgery	Any episode of urinary retention reported by the patient or nursing team
Incidence of shivering	From injection of bupivacaine for spinal anesthesia to 24 hours after surgery	Any episode of shivering reported by the patient or nursing team
Incidence of headache	From injection of bupivacaine for spinal anesthesia to 24 hours after surgery	Any episode of headache reported by the patient or nursing team
Quality of sleep	At 24 hours after surgery	Described by the patient as good or bad
Duration of sensory block	At 5,10, 20 and 30 minutes following spinal anesthesia, then every 15 minutes until regression by 2 dermatomes and every 30 minutes thereafter until complete recovery, approximately 4 hours after surgery	Loss of pinprick sensation by Von Frey filaments from the injection of bupivacaine for spinal anesthesia until complete recovery

Trial Locations

Locations (1)

Centre Hospitalier de l'Université de Montréal (CHUM); 🇨🇦 Montreal, Quebec, Canada