RCT of SPG Blocks for Post-dural Headache

Study Overview
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Brief Summary
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The purpose of the study is to assess the effectiveness of the SPG block with lidocaine vs. SPG block with placebo on preventing the need for EBP in women who develop PDPH after accidental dural puncture during placement of LEA for labor.

Detailed Description
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The postdural puncture headache (PDPH) is a well-documented complication of dural puncture. Depending on a number of factors, the overall incidence of PDPH following unintended dural puncture with an epidural placement needle is typically around 50%, but can be as high as 70% for certain populations.(1, 2, 3) The headache is characterized by being frontal or occipital in nature, with a typical onset of 6-72 hours after dural puncture. It is normally exacerbated by the upright position and improved by the supine position. Associated symptoms may include photophobia, nausea, vomiting, dizziness, tinnitus, neck stiffness, decreased hearing and visual changes. (2) These symptoms tend to be extremely debilitating in affected patients, severely limiting their functional capacity until the resolution of the headache.(2) The compromise is even greater when considering these women also need to care for a newborn, as the time after birth is important for forming attachment and encompasses many new obligations for the new mother. The treatment of the PDPH often begins with conservative treatment including supportive therapies such as hydration, bed rest, acetaminophen, NSAIDs, and oral opioids. In addition, some evidence exists for the use of caffeine (1,2). While these do not hasten recovery, they may improve symptoms. For PDPH of all etiologies, 72% will resolve spontaneously in 7 days and 89% by 14 days. (1) For patients with moderate to severe symptoms or long lasting headaches, the gold standard for treatment of headaches that do not resolve is the epidural blood patch (EBP) (1,2,4). This treatment has been shown to be effective in 70-98% of patients (1,2,4). However, it has numerous contraindications including: fever, infection, coagulopathy, active neurological disease, patient refusal. In addition, a potential complication is yet another dural puncture. Also, while the EBP is generally very safe, it is an invasive procedure with its own complications; it has been associated with very rare but serious complications including: moderate long-lasting backache, meningitis, epidural abscess formation, epidural hematoma formation, and neurologic deficit development. (5-8) The sphenopalatine ganglion (SPG) is a parasympathetic ganglion with fibers that innervate the cerebral and meningeal blood vessels cause vasodilation and activation of nociceptive fibers in the meninges, which is perceived as referred pain from the head by the sensory cortex. (9) So blockade of these fibers can theoretically relieve headache symptoms from other causes. The SPG block has been safely used for many years to treat chronic facial or head pain from cluster headaches, trigeminal neuralgia, postherpetic neuralgia, atypical facial pain from cancer, and CRPS I and II. (9) The SPG block is safe and easy to perform. The only contraindications include patient refusal, a true allergy to local anesthetic, and Hereditary Hemorrhagic Telangiectasia (HHT). (9,10) Documented potential complications include transient nausea and epistasis. (9,10) The SPG is located in the pterygopalatine fossa, which is just posterior to the middle turbinate, and anterior to the pterygoid canal. It is about 5 mm in size and there is a 1 to 1.5 mm-thick layer of connective tissue and mucous membrane surrounding the ganglion, so drug enters easily by a topical application. (9-11) There are multiple approaches to the blockade of this ganglion, but the easiest and least invasive is the transnasal approach involving entering the nare with the application of lidocaine jelly on a cotton swab directed posteriorly in the nasal passage to the SPG. (9) The cotton swab should remain in place for 10 minutes. (9,10) Recently, the SPG block has also been shown to be effective in relieving the symptoms of the PDPH in case series and case reports. One case series performed SPG blocks in 3 parturients with confirmed PDPH in the emergency room using 2% viscous lidocaine. All 3 patients had good relief after the intervention and did not require EPB. The authors suggested that the procedure can be safely and accurately performed in the emergency room, which will reduce visit time, provide good pain relief, and the EBP can be deferred. (10) Another case series of 32 patients with confirmed PDPH of multiple etiologies showed that the SPG block prevented the need for EBP in 69% of the cases. (12) In addition, a recent randomized placebo controlled trial of SPG block vs. saline for acute headache in the ER showed that for patients with acute anterior headache, SPG block with bupivacaine resulted in a reduction of HA symptoms. However, reduction of headache symptoms was also seen in the SPG block with saline group, indicating a possible placebo effect of the performance of the block. (13) The purpose of the study is to assess the effectiveness of the SPG block with lidocaine vs. SPG block with placebo on preventing the need for EBP in women who develop PDPH after accidental dural puncture during placement of LEA for labor.

Official Title
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A Multicenter Double Blinded Randomized Controlled Trial of the Efficacy of the Sphenopalatine Ganglion Block for the Treatment of the Postdural Puncture Headache After Labor Epidural

Conditions
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Post-Dural Puncture Headache

Intervention / Treatment
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* Drug: Lidocaine HCl Gel 2%
* Drug: placebo gel


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Females age 18-50 Post Dural Puncture Headache after documented accidental dural puncture during placement of LEA for labor and no better explanation for headache onset of HA within 72 hours of delivery. Exclusion Criteria: true allergy to local anesthesia Hereditary Hemorrhagic Telangiectasia inability to understand pain scores and other questionnaires inability to speak English contraindication to acetaminophen or NSAIDs temperature >38.5 C prior Epidural Blood Patch done for this headache

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 50 Years

Sexes Eligible for Study
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Female

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: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Lidocaine<br>Transnasal blockade of SPG approach involving the application of 2 cc (approximately the size of a pea) of 2% lidocaine jelly on a cotton swab directed posteriorly towards the SPG in the nasal passage bilaterally. Cotton swab will be inserted to the back of the nasal passage until it can no longer be inserted any further. The cotton swab should remain in place for 15 minutes on both sides simultaneously. The patient will be instructed on how to perform this procedure on themselves, and they will be given supplies for a 7-day supply of medication to be administered two times per day at approximately 12 hour intervals. | Drug: Lidocaine HCl Gel 2%<br>* Patients will be prescribed a regimen of 1 g acetaminophen q 8hrs alternating with 600 mg ibuprofen q 6 hours. In addition they will be instructed to continue oral fluid hydration and minimal activity for 24 hours. At 2-hours following the SPG blockade an EBP will be offered to patients. Patient will also be informed that they can request an EBP at any time. The SPG blockade will be performed twice daily in the hospital and twice daily at home, by the patient. The patient will also be informed, if that at anytime, they would like an EBP, it can be provided. While the study is being conducted, patients will not be offered a SPG block unless enrolled in the study.<br>|
| Placebo Comparator: Placebo<br>Transnasal blockade of SPG approach involving the application of 2 cc (approximately the size of a pea) of nasal saline jelly on a cotton swab directed posteriorly towards the SPG in the nasal passage bilaterally. Cotton swab will be inserted to the back of the nasal passage until it can no longer be inserted any further. The cotton swab should remain in place for 15 minutes. The patient will be instructed on how to perform this procedure on themselves, and they will be given supplies for a 7-day supply of medication to be administered up to two times per day at approximately 12 hour intervals. | Drug: placebo gel<br>* Patients will be prescribed a regimen of 1 g acetaminophen q 8hrs alternating with 600 mg ibuprofen q 6 hours. In addition they will be instructed to continue oral fluid hydration and minimal activity for 24 hours. At 2-hours following the SPG blockade an EBP will be offered to patients. Patient will also be informed that they can request an EBP at any time. The SPG blockade will be performed twice daily in the hospital and twice daily at home, by the patient. The patient will also be informed, if that at anytime, they would like an EBP, it can be provided. While the study is being conducted, patients will not be offered a SPG block unless enrolled in the study.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Epidural Blood Patch | Proportion of postpartum women with a postdural puncture headache (PDPH) requesting epidural blood patch (EBP) | 7 days after treatment with lidocaine or placebo block | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Verbal Numerical Pain | Verbal Numerical Pain score (0-10) | 30 minutes, 1 hour, 2, hour, 1 day, 2, days, 3 days, 4 days, 5 days, 6 days, and 7 days after treatment with lidocaine or placebo block | 
| Verbal Functionality Score | Daily Questionnaire regarding functionality | 1 day, 2, days, 3 days, 4 days, 5 days, 6 days, and 7 days after treatment with lidocaine or placebo block |