Clinical Case 070: Postpartum headache


This next case is complimented by a great review article, which was sent to me when I phoned for some advice.

Klein AM, Loder E (2010) Postpartum Headache. International Journal of Obstetric Anaesthesia October;19(40) 422-30

Its Saturday morning and you have just opened up a crisp copy of the Australian when get a call from your obstetric colleague asking you to review a 30yo, G3P3, 28hours after an uncomplicated elective caesarean section by spinal anaesthesia, with an unremitting headache.

Interestingly she was diagnosed with a pulmonary embolus at 20weeks and has been on therapeutic subcutaneous enoxaparin (70mg BD) since then but has been otherwise well. Her thrombophillic work-up was negative.

Her enoxaparin was stopped 12 hours before her caesarean and platelet count on the day was 160 x10(9)/L.

The headache is described occipitally and moves frontally when she sits up or leans forward.  She reports some neck stiffness radiating occipitally but no photophobia.

Her observations have been normal (Temp 36.5c HR 65bpm BP 100/70mmhg RR 12/min Sa02 98%RA).

 

History + examination + investigation is always a great place to start! Klein & Loder suggests a history driven approach.

Began slowly last night, 8 hours post-caesarean section. It is overwhelmingly worse on upright posture and frontal in location. Relieved in the supine position.

No previous history of headaches before and during pregnancy.

Has not taken any herbal, over the counter or recreational drugs in the last few weeks.

Headache history is absolutely critical as a number of red flags and significant causes can be ruled out.

Postural headache -> Think low CSF pressure headache, Postdural puncture headache (PDPH).

History of similar headaches -> 1/3 to half of women with migraine will have a postpartum headache and the nature of symptoms are similar to their previous headaches.

Headache associated with antenatal/post-natal history of hypertension, proteinuria or seizure -> Postpartum Preeclampsia.

Abrupt headache -> think aneurysm subarachnoid haemorrhage, cerebral venous thrombosis and a vascular cause.

Spinal anaesthesia preformed at L4/L5 with a 25gauge Whitacre spinal needle.

Needle gauge is directly related to the incidence of headache as a 16G needle will cause headache in about 75% of patients compared with 3% using a 25G needle, 2-12% 26G and <2% with a 29G needle.

 Furthermore bevel position is important as pencil point needles (Whitacre & Sprotte) part the dura rather than cutting through it and are considered to make a smaller puncture, reducing the incidence of headache. 

Patient has current history of pulmonary embolus but no identified thrombophillic condition other than being pregnant!

Red flags to watch for:

New neurological signs with headache

New headache, especially unilateral

Headache not relieved by analgesia

Sudden uncontrollable vomiting

Deterioration of mental status

Underlying medical issue (bleeding disorder, immunocompromised)

Observations as noted above. Cardiovascular, respiratory and neurological examination were normal. Her spinal site was clean with no evidence CSF leakage, swelling or tenderness.

Directed by history and possible causes

⇒ Basic observations BP (both arms), temperature

⇒ Spinal site inspected for signs of leak, inflammation or tenderness

⇒ Neurological examination (localizing signs), hyper-reflexia and conscious state

MSU showed some ketones but was otherwise normal. Post operative FBE showed a haemoglobin of 110g/L.

No further investigation was considered, as driven by history and examination, her headache appears postural, making a diagnosis of Post-Dural Puncture headache most likely.

Relevant investigations:

MSU -> assessing for proteinuria to support a diagnosis of a pre-eclamptic headache

CT-Brain non contrast -> if there was clearly any hint of new neurological deficits, change in mental status or a history suggestive of a sudden maximal headache

Transfer for MRI/MRA -> If there is any doubt about the diagnosis particularly if there are focal neurological signs or vision changes.

Postdural puncture headaches are due to a low CSF pressure sustained after an unintended dural puncture (which does not heal spontaneously) if an epidural or spinal technique has been used for labour and delivery.

Diagnostic criteria

         A. Worsened headache within 15mins after sitting or standing that improves within 15mins of lying down, with at least criteria C and D

         B. Dural puncture preformed

         C. Headache within 5 days after dural puncture

         D. Headache resolves either: Spontaneously in 1 week or within 48hrs of EPB

(Headache Classification Subcommittee of International Headache Society 2004)

1 in 100 obstetric patients experience an unintentional dural puncture during epidural catheter insertion. 55-80% of them will develop a PDPH.

Operator skill and fatigue directly impacts upon the incidence of PDPH. Junior staff and night work are clear factors, with the junior trainee learning rate being as high as 1:20.

These can persist for up to a week and are moderate to severe in 50% of cases.

The incidence following a diagnostic lumbar puncture is between 30-50% and 1-5% following spinal anaesthesia.

1) Conservative management  2) Epidural intervention: Epidural blood patch (EBP)

Conservative management -> Oral and intravenous management

PDPH is a self-limiting condition with the majority of headaches resolving within a week with conservative management.

Oral hydration is a popular therapy with very little evidence to support it, however patients with PDPH should not become dehydrated and should be encouraged to stay hydrated.

Oral caffeine has been used as a conservative option for many years with some low level evidence to support it. It can be given orally, intramuscularly or intravenously.

A 2011 Cochrane review on Drug Therapy in PDPH showed that caffeine resulted in a significant decrease proportion of patients with PDPH with gabapentin, theophylline and hydrocortisone decreasing pain scores. The significance of this conclusion is questioned due to the limited number of studies and sample sizes.

Recently case controlled study published showed that Gabapentin was effective in 17 patients whose headaches were refactory to multiple epidural blood patches. However this should be used with caution in breastfeeding mothers as the effect on the neonate is not fully know and has shown harm in animal models.

Many conservative measures have been studied with none reaching significance. Simple but prudent escalating analgesia with hydration is essential together with daily follow up and consideration of an EBP is an excellent standard of care.

EBP was described 50 years ago to treat post-dural puncture and has been considered as the most effective treatment. Evidence supporting its use and efficacy is lacking with a recent 2011 Cochrane review not finding any superiority for its use due to a lack of trial participants.

Furthermore most studies and reviews do not distinguish between the use of a EBP for PDPH caused by an epidural needle (16-18G) vs a spinal needle (e.g. 25G).

The proposed mechanism of the EBP is tamponade of the dural leak (forming a fibrin clot) and simultaneously raising the subarachnoid pressure.

Despite its varying success, few anaesthetists would delay treating a woman incapacitated by PDPH given that there are no other treatments that offer the hope of a rapid permanent symptomatic treatment Paech adds.

This is because obstetric patients are required to mobilise early and hence relief of symptoms is crucial.

Efficacy EBP following spinal needle puncture (>95%), Epidural 16-18G needle (30-75%). Furthermore up to 95% of obstetric patients obtain short term complete or partial relief from symptoms and 30-70% remain headache free after several days.

“Cure” from EBP should be consented at best 50% with 40% requiring a second EBP. The timing of the EBP is a debated issue with most articles suggesting between 24 and 48hours following the onset of the headache.

EBP is best preformed with 2 operators: One preforming the epidural and one simultaneously preforming a venipuncture on the patient both employing full asepsis (gowns, gloves, hats and mask).

Once the epidural space is found a pre-determined volume of blood is injected slowly and stopped if there is any discomfort.

Patient should lie flat for a minimum of 2 hours following the procedure. Following this, patients should be advised to stay hydrated, avoid heavy lifting, straining and coughing.

Contraindications to EBP: Sepsis, coagulopathy and patient refusal

The most effective volume of autologous blood is not known. Most commonly between 15-20mls is used.

In a recent RCT Paech et al looked at 3 volumes of blood for EBP in PDPH. They found no differences in headache pain scores between the 20ml and 30mls group but noted an increased incidence of back pain in the 30ml group.

These findings supported the use of 20mls when treat PDPH which is the standard of care across most institutions.

Based on her thromboembolic issue and bleeding risk we elected to treat her conservatively.

She responded well over the next 24hours to regular simple analgesia, breakthrough oxycodone and was kept well hydrated.

She did not report any new symptoms and her neurological observations remained stable.

Special thanks to Dr Nolan Mcdonnell, Staff Specialist Anaesthetist at King Edward Memorial Hospital in Perth, for his advice and peer review of this piece.

References

Klein AM, Loder E (2010) Postpartum Headache. International Journal of Obstetric Anaesthesia October;19(40) 422-30

http://www.ncbi.nlm.nih.gov/pubmed/20833030

Turnbull DK, Shepherd BD (2003) Post-dural puncture headach: pathogenesis, prevention and treatment. British Journal Of Anaesthesia 91 (5):718-729

http://bja.oxfordjournals.org/content/91/5/718.full

Paech M (2005) Epidural blood patch – myths and legends. Canadian Journal of Anesthesia 52:3 ppR1-R5

http://link.springer.com/article/10.1007%2FBF03023087?LI=true

Campbell NJ (2010) Anaesthesia Tutorial of the week 181 – Effective Management of the post dural puncture headache

http://totw.anaesthesiologists.org/2010/06/01/post-dural-puncture-headache-181/

Paech MJ et al (2011) The volume of blood for epidural blood patch in obstetrics: a randomized, blinded clinical trial. Anesthesia and Analgesia, 113:1 126-133

http://www.ncbi.nlm.nih.gov/pubmed/21596867

Ghaleb A et al (2012) Post-dural puncture headache. International Journal of General Medicine (5)45-51

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3265991/

Basurto OX et al (2011) Drug Therapy for treating pos-dural puncture headache (Review) The Cochrane Collaboration Library Issue 8

http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD007887.pub2/abstract

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