ASRA Pain Medicine Update

A 31-year-old G2P0010 at 39+2 weeks presents in active labor requesting epidural. She denies any complications with current pregnancy.

PMH: Chronic headaches, BMI of 39
PSH: Appendectomy 
Meds: Prenatal vitamins
Allergies: Penicillin
Physical Exam: BP 138/82, HR 101, RR 20, Temp 98.9
Labs: Cr 0.8, Plt 190 

Patient is positioned, and you begin placement of the epidural. During the procedure, the loss-of-resistance syringe abruptly backfills with fluid.  

1. What has happened, and how would you proceed?

Answer: 

• Given the information, it seems the patient may have unintentional dural puncture (wet tap). To confirm diagnosis, the clear fluid can be tested for:
  • Can order beta-2 transferrin, specific to cerebrospinal fluid (CSF)
  • Can test for glucose using glucometer or urine dipstick; glucose will not be present in normal saline used in loss-of-resistance syringe.
• One option is to withdraw the epidural needle and reattempt at a level above or below.
• An intrathecal catheter can be placed if you anticipate continued difficult epidural placement. It is CRITICALLY IMPORTANT to have a Continuous Spinal Management Protocol in place to prevent adverse events including clear labeling of spinal catheters and knowledgeable nursing staff.
• Discussion should be held with patient regarding the increased risk and signs and symptoms of PDPH. ¹

2. What are the risk factors for developing a PDPH?

Answer: 

• Patient factors: Female gender, pregnancy, age 18-50 years, prior history of headache, low BMI (25 or less)
• Procedural risk factors: Larger conventional needle (larger than 25 gauge), sharp cutting tip (Quincke), needle orientation (bevel perpendicular to long axis of spine), operator inexperience ^2,3

3. What are some protective factors concerning development of PDPH?

Answer:

• Patient factors: Male gender, non pregnant, extreme of age (<18 years, >50 years), obesity (BMI 31.5 or greater)
• Procedural factors: Pencil tip (Whitacre and Sprotte), smaller needle size (25 or 27 gauge), needle orientation (bevel parallel to long axis of the spine) ⁴

4. What is the chance of this patient developing a PDPH after unintentional dural puncture?

Answer: 

• After accidental dural puncture with an epidural (18-gauge Tuohy) needle, the risk of a headache postpartum is about 50%. When a 25-gauge Whitacre needle is used, the incidence of PDPH is about 3%-5%. ^3,5

5. After an unintentional dural puncture, what measures can you take to reduce the chance of PDPH for this patient?

Answer: 

• There are mixed data concerning efficacy of prophylactic measures.
• Things that have not been shown to decrease risk of developing PDPH include caffeine, aggressive hydration, lying flat after procedure, or epidural morphine prophylaxis.  
• Some other recommendations are: 
  • IV cosyntropin: One prospective randomized controlled trial found a reduction in the incidence of PDPH and the need for epidural blood patch after unintentional dural puncture in parturients who received 1mg of cosyntropin. Another study concluded cosyntropin may be a reasonable treatment for PDPH in patients where epidural blood patch is contraindicated. ^6,7
  • Leaving an intrathecal catheter in place for 24-48 hours may reduce the frequency of developing a PDPH. 
  • Replacing lost CSF: Limited evidence supports that immediate injection of 10 mL intrathecal normal saline after a wet tap or injection of 10 ml of normal saline prior to the removal of an intrathecal catheter significantly reduced the incidence of PDPH. ^2,8,9

6. On postpartum day 1, the patient develops a headache. What is the differential diagnosis of headache post-delivery? 

Answer: 

• Headaches: Migraine, cluster, tension
• Postdural puncture headache 
• Postnatal depression headache
• Caffeine withdrawal 
• Preeclampsia
• Subdural bleed
• Meningitis
• Pneumocephalus 
• Head trauma (domestic abuse)
• Stroke (ischemic or hemorrhagic)
• Malignancy ^5,10

7. What is the clinical presentation of PDPH?

Answer: 

Patients typically present 12-24 hours following dural puncture (however, can be up to five days) with frontal or occipital headache that is worse with sitting or standing and relieved by lying flat. Patients may have associated symptoms such as neck stiffness, nausea, visual changes, or auditory disturbance. ^1,11

8. What are the diagnostic criteria of PDPH?

Answer: 

1. Orthostatic headache caused by low CSF pressure and criteria (2) and (3) must be fulfilled. 
2. Dural puncture has been performed whether intentional or unintentional, recognized or not.
3. Headache develops within five days of possible dural puncture. 
4. Accompanied symptoms (usually present, but not always): Neck pain, tinnitus, changes in hearing, photophobia, nausea
5. Headache resolves either spontaneously within two weeks or after autologous epidural lumbar blood patch. ^1,2,4,5
   

9. After evaluation, you suspect the patient has a PDPH. What is the management of PDPH? 

Answer: 

• Treatment is based on severity of headache.
• Mild PDPH is defined as patients who can perform activities of daily living. For these patients, conservative treatment is preferred, including bedrest as needed, oral analgesics (acetaminophen, NSAIDS, Fioricet®), hydration, caffeine, and antiemetics for symptomatic management. Headache will resolve within 1-2 weeks. ^2,8,9
• Debilitating PDPH is defined as patients who are unable to tolerate sitting/standing position, unable to perform activities of daily living, and presence of headaches refractory to conservative measures. Epidural blood patch (EBP) should be offered to these patients. Sphenopalatine ganglion and/or occipital nerve block can be considered based on circumstances.
• There is limited evidence for the use of gabapentin, aminophylline, cosyntropin for treatment (see above), hydrocortisone, and neostigmine/atropine for decreasing the severity of PDPH. ^6,7

10. Is there an indication for urgent imaging or epidural blood patch (EBP)?

Answer: 

• There are multiple case reports of non-postural headaches persisting after PDPH in the setting of a spontaneous subdural hematoma. Thus, any headache that is or becomes non-postural and persistent warrants further consideration. Also, imaging to rule out other intracranial processes is warranted in the case of cranial nerve palsy. ^5,12,13
  

• If successful, EBP usually provides immediate relief and is the gold standard for treatment of PDPH.
• Success rate following first EBP is between 65%-98%.
• Success rate after second EBP is 98%. ³

Answer: 

• The decision to place an EBP should be weighed against the risk of repeated dural puncture. 
• Furthermore, experienced providers should perform the EBP.  
• EBP is performed by sterile phlebotomy followed by sterile injection of blood through an epidural needle into the epidural space.
• Step by step procedure entails:

1. Standard monitors are placed and a free-flowing IV is secured in case of emergency. 
2. Two providers are needed to perform an EBP due to the need for two sterile fields - one for blood draw and the other for epidural access.
3. Epidural access is achieved first unless difficult IV access is anticipated.
4. Once the epidural space is identified, autologous venous blood is injected through the epidural needle. Optimal volume of injection is 20 cc. Injections should be stopped if patient complains of significant pain, pressure, or paresthesia. ¹⁴
5. Headache symptoms should improve within seconds to minutes but may take 24-48 hours. 
6. Patient may report a sensation of fullness in the back. Motor and gross sensory testing of the lower extremities should be performed and documented prior to discharge.
7. Patient should lie flat for 1-2 hours post procedure. ^1,5,11 

13. What are the potential complications of not performing an EBP?

Answer:

• PDPH is thought to cause an increased risk of subdural hematoma due to brain sagging resulting in traction and subsequent tearing of bridging meningeal veins. 
• There is a potential increased risk of cerebral venous sinus thrombosis due to the compensatory cerebral vasodilation in the setting of CSF hypotension coupled with postpartum hypercoagulability. ¹⁵
• There is a risk of developing chronic headaches.

• Sphenopalatine ganglion block (SPGB) has been used successfully to treat PDPH. SPGB can relieve headaches for up to 18 hours thus this block may have to be repeated.  It may be beneficial for patients in whom EBP may be contraindicated. 
• Transnasal approach consists of a cotton tip applicator soaked in 2%-4% lidocaine or 0.25%-0.5% bupivacaine inserted into bilateral nares aiming for the posterior pharynx. The applicator tips are then left for about 10 -15 minutes. After the procedure, most patients have immediate relief lasting a few hours to permanent resolution of symptoms, but this procedure is still controversial. Be aware that there may be an increased chance of nosebleed in the postpartum period due to increased vascularity of the nasal mucosa. Addition of epinephrine to the solution can minimize the risk of nose bleed. ¹⁶
• Alternatively, the block can be performed invasively via the suprazygomatic approach in which a 25-gauge needle is inserted superior to the zygomatic arch and posterior to the orbital rim, directed 10 degrees anterior and 45 degrees caudal, and inserted 5 cm to the pterygopalatine fossa where 5 ml of 0.5% ropivacaine is deposited. If resistance is met early, it is likely bone; the needle can be redirected slightly to walk off. This is repeated bilaterally. ¹¹

15. What are the contraindications to an EBP?

Answer:

• Anticoagulation/coagulopathy
• Infection at the injection site
• Patient refusal or lack of cooperation
• EBP should be avoided in the setting of active infections (mastitis, endometritis, fever). ⁵

References

1. American Society of Anesthesiologists. Practice guidelines for obstetric anesthesia: an updated report by the american society of anesthesiologists task force on obstetric anesthesia and the society for obstetric anesthesia and perinatology. Anesthesiology 2016; 124:270-300. https://doi.org/10.1097/ALN.0000000000000935
2. Baysinger CL, Pope JE, Lockhart EM, Mercaldo ND. The management of accidental dural puncture and postdural puncture headache: a North American survey. J Clin Anesth 2011 Aug;23(5):349-60. https://doi.org/10.1016/j.jclinane.2011.04.003
3. Kuntz KM, Kokmen E, Stevens JC, et al. Post-lumbar puncture headaches: experience in 501 consecutive procedures. Neurology 1992 Oct;42(10):1884-7. http://dx.doi.org/10.1212/WNL.42.10.1884 
4. Choi PT, Galinski SE, Takeuchi L, et al. PDPH is a common complication of neuraxial blockade in parturients: a meta-analysis of obstetrical studies. Can J Anaesth 2003;50:460–9. https://doi.org/10.1007/BF03021057
5. Bateman BT, Cole N. Sun-Edelstein C, et al. Post dural puncture headache. UpToDate®. Available at:  https://www.uptodate.com/contents/post-dural-puncture-headache?search=post%20dural%20puncture%20headache&source=search_result&selectedTitle=1~49&usage_type=default&display_rank=1. Accessed May 9, 2022.
6. Hakim SM. Cosyntropin for prophylaxis against postdural puncture headache after accidental dural puncture. Anesthesiology 2010 Aug;113(2):413-20. https://doi.org/10.1097/ALN.0b013e3181dfd424
7. Hanling SR, Lagrew JE, Colmenar DH, et al. Intravenous cosyntropin versus epidural blood patch for treatment of postdural puncture headache. Pain Med 2016 Jul 1;17(7):1337-42. https://doi.org/10.1093/pm/pnw014. 
8. Charsley MM, Abram SE. The injection of intrathecal normal saline reduces the severity of postdural puncture headache. Reg Anesth Pain Med 2001 Jul-Aug;26(4):301-5. https://doi.org/10.1053/rapm.2001.22584
9. Peralta FM, Wong CA, Higgins N, et al. Prophylactic intrathecal morphine and prevention of post-dural puncture headache: a randomized double-blind trial.  2020 May;132(5):1045-52. https://doi.org/10.1097/ALN.0000000000003206. 
10. Ansari J, Flood P. Severe sequelae, chronic headache linked to PDPH. ASA Monitor 2020; 84:1–16.
11. Harrington B, Reina MA. Postdural puncture headache. New York Society of Regional Anesthesia. Available at: https://www.nysora.com/foundations-of-regional-anesthesia/complications/postdural-puncture-headache/. Accessed May 9, 2022.
12. Buddeberg BS, Bandschapp O, Girard T. Post-dural puncture headache. Minerva Anestesiol 2019 May;85(5):543-53. https://doi.org/ 10.23736/S0375-9393.18.13331-1.  
13. Guglielminotti J, Landau R, Li G. Major neurologic complications associated with postdural puncture headache in obstetrics: a retrospective cohort study. Anesth Analg 2019 Nov;129(5):1328-36. https://doi.org/10.1213/ANE.0000000000004336
14. Paech MJ, Doherty DA, Christmas T, et al. The volume of blood for epidural blood patch in obstetrics: a randomized, blinded clinical trial. Anesth Analg 2011 Jul;113(1):126-33. http://dx.doi.org/10.1213/ANE.0b013e318218204d
15. Lim G, Zorn JM, Dong YJ, et al. Subdural hematoma associated with labor epidural analgesia: a case series. Reg Anesth Pain Med 2016 Sep-Oct;41(5):628-31. https://doi.org/10.1097/AAP.0000000000000455
16. Nair AS, Rayani BK. Sphenopalatine ganglion block for relieving postdural puncture headache: technique and mechanism of action of block with a narrative review of efficacy. Korean J Pain 2017;30(2):93-97. https://doi.org/10.3344/kjp.2017.30.2.93