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Severe headache following an epidural ‘top-up’
Severe headache following an epidural ‘top-up’ J. L. Shah Department of Anaesthetics, Dudley Road Hospital, Birmingham, UK
SUMMA R Y. Half an hour after a normal delivery under epidural analgesia, a patient was given a top-up of 10 ml 0.25% bupivacaine for suture of a small vaginal tear. The patient developed severe headache, nausea and vomiting immediately after the top-up. Initially these symptoms were attributed to a complication of epidural analgesia. However, a raised epidural pressure led to a diagnosis of hypertensive encephalopathy.
Severe headache, nausea, vomiting and photophobia are common after an inadvertent dural puncture in a young parturient. These symptoms result from excessive loss of cerebrospinal fluid (CSF) from the dural rent, especially following straining during delivery. Headache, nausea and vomiting may also occur in hypertensive disease of pregnancy, especially after the use of ergot preparations.‘*’ A case is described where these symptoms occurred immediately after an epidural top-up and gave rise to difficulty in diagnosis.
sia was established at L2/3 interspace without difficulty, and 10 ml 0.25% bupivacaine produced good analgesia. After this her blood pressure remained normal and varied between 116/69 and 136/78 mm Hg. During labour, a small volume of urine passed at 06:OO had a trace of protein, and a catheter specimen of urine obtained at 09:OOshowed heavy proteinuria of + + + on dip stick testing. For the remainder of labour, two further 10 ml top-ups of 0.25% bupivacaine, given by the midwife, produced good analgesia. At 11:40 she had a spontaneous delivery of a live male infant weighing 3.70 kg. At delivery she received an intramuscular injection of 1 ml Syntometrine (0.5 mg ergometrine with 5 units of synthetic oxytocin). Her blood pressure soon after delivery was 155/83 mm Hg. 35 min after the delivery, her blood pressure prior to a top-up for suture of a vaginal tear was 166/85 mm Hg. She was given a 10 ml top-up of 0.25% bupivaCaine by the midwife, and immediately after the epidural injection she complained of severe frontal headache. She was nauseated and retched uncontrollably. Since the onset of her headache coincided with an epidural top-up, the on-call trainee obstetrician asked the author for an anaesthetic opinion. At 12:20, 5 min after the top-up, her blood pressure had risen to 170/95 mm Hg. She was extremely distressed with severe frontal headache, nausea and violent retching. She was conscious and cooperative, and did not show any signs of impaired cerebral function. There was no neck stiffness or papilloedema. Her reflexes appeared normal but at the time, being distressed, she was constantly moving her arms and legs, and it was difficult to elicit hyper-reflexia. She was able to move all her limbs. Aspiration of the epidural catheter was negative, and there was no evidence of an inadvertent dural tap.
CASE REPORT A 23-year-old primigravida was admitted to the labour ward at 01:OO in early labour. Her antenatal course was uneventful with an average blood pressure of 1IO/60 mm Hg, and no proteinuria or oedema. At 04:30 she received 100 mg pethidine (meperidine) and 25 mg promazine for analgesia. Because of slow progress, at 07:30 her labour was augmented with an infusion of Syntocinon (synthetic oxytocin devoid of the pressor-inducing effects of ergot derivatives). Half an hour later, at 08:OO she became distressed and requested epidural analgesia. During labour her blood pressure had been normal and there were no contraindications to epidural analgesia. Five minute blood pressure recordings using an automatic blood pressure monitor (Critikon Dinamap TM 1846SX) were started prior to establishing an epidural block. Blood pressure, recorded soon after a painful contraction, was 135/90 mm Hg and returned to 130/85 5 min later. At 08: 15 epidural analgeCorrespondence to: J. L. Shah, Department of Anaesthetics, Dudley Road Hospital, Birmingham B18 7QH, UK. 29
30
International Journal of Obstetric Anesthesia
The epidural pressure was measured using the epidural catheter as a manometer.3*4 To do this the patient was placed in the left lateral position, the epidural catheter held vertically, and the bacterial filter disconnected from the catheter to allow the fluid level in the catheter to descend. The vertical distance between the final level of the liquid meniscus and the lumbar puncture after allowing for the capillarity effect (with a 16G Portex catheter the capillarity effect is 2 cm HzO) gave an epidural pressure in this patient of 20 cm H,O, which is greater than normal.4 A presumptive diagnosis of severe pregnancy induced hypertension was made, an immediate intravenous injection of 5 mg diazepam given and the arterial pressure monitored. Over the next 3 h the blood pressure slowly declined from 170/95 to lSO/SS mm Hg without further intervention. She still complained of slight headache. Since her blood pressure was declining, it was decided to transfer her to the postnatal ward. The epidural catheter was removed and the puncture site dressed. Whilst being transferred to her bed, the patient had a grand ma1 seizure. She was treated immediately with intravenous diazepam, oxygen by a face mask, and intravenous infusion of chlormethiazole. Within a few minutes her blood pressure settled at 130/80 mm Hg. After the convulsion she had proteinuria of 1 to 2 + + for 3 h and a trace for a further 7 h. With treatment her condition improved over the next 20 h and she made an uneventful recovery. Both mother and baby were discharged home 3 days later in perfect health.
DISCUSSION Severe postpartum headache may occur with an inadvertent dural puncture, hypertension of pregnancy or a subarachnoid haemorrhage. Nausea, vomiting and retching may accompany the headache in all three conditions. An inadvertent dural tap may not be identified at the time of performing the epidural puncture,5*6 and becomes evident only when the patient develops postpartum headache. The onset of headache is variable, and may occur early if an excessive amount of CSF is lost during straining at delivery. The CSF pressure is reduced in patients suffering from post dural puncture headache.’ Since the CSF pressure directly affects the epidural pressure,3 it too should be decreased. Injection of saline has been used to relieve the post dural puncture headache.* In our patient, there was no evidence of dural puncture, the epidural pressure was high, and the headache had been precipitated by the injection of fluid into the epidural space. Syntometrine, which contains 0.5 mg ergometrine, is widely used to prevent postpartum haemorrhage.
Ergot preparations are known to cause severe vasoconstriction and a rise in blood pressure. Severe hypertension, cerebral oedema and convulsions have been reported after its use.l*’ In these reports, headache, nausea and retching preceded the convulsions. Like other reported cases,’ our patient developed hypertension after ergot administration in spite of having normal blood pressure throughout her pregnancy. The single raised pressure during labour was, at the time, attributed to painful contractions. Sudden onset of headache is characteristic of a subarachnoid haemorrhage. However, other signs of cerebral irritation would be expected. In severe cases the patient is semistuporous or drowsy, confused and irritable when roused. Our patient was alert and cooperative, with normal plantar reflexes and subarachnoid haemorrhage seemed unlikely. A significant feature in our patient was that the onset of headache coincided with an epidural top-up. Injection of fluid into the epidural space may compress the dural sac and cause a shift of CSF from the spinal to the cranial compartment and increase the intracranial pressure. l”*ll The lumbar epidural pressure in the immediate postpartum period is reported to be 13.1 f3.0 cm Hz04. The increased epidural pressure in our patient may have been secondary to an increased intracranial pressure which is known to occur in severe pre-eclampsia.” It seems likely that after the injection of Syntometrine (containing 0.5 mg ergometrine), our patient developed hypertension with a degree of hypertensive encephalopathy. The epidural top-up by producing a shift of CSF from the spinal to the intracranial compartment may have further increased her intracranial pressure and precipitated her symptoms. The initial diagnosis of pregnancy induced hypertension in this patient was based on severe headache associated with nausea, retching, high arterial pressure and a raised epidural pressure. However, the recognition of this disorder was delayed because the patient had normal blood pressure without proteinuria or oedema during pregnancy and a normal blood pressure during labour. The misconception that headache during or immediately after labour is commonly due to a complication of epidural analgesia may also have delayed the acceptance of pregnancy induced hypertension as the cause. The final diagnosis of pregnancy induced hypertension was only accepted when the patient had a convulsion. The primary treatment in this patient should have included antihypertensive therapy, which might have prevented the seizure. The patient was lightly sedated by the initial dose of diazepam which may have delayed the occurrence of convulsions. It has been suggested that the epidural pressure is not a single measurable entity, but a complex dynamic equilibrium of forces between the vertebral column and the dura.13 Various factors, including the move-
Severe headache following an epidural ‘top-up’
ment of CSF within the spinal dura and of the blood within the vertebral canal are known to affect the epidural pressure. However, it is the author’s opinion that provided the patient stays still, the epidural pressure is a close approximation of the prevailing spinal CSF pressure and can easily be measured with a simple manometer. It has recently been shown that a pressurised Macintosh balloon may not deflate in the epidural space. l4 It seems likely that when a small volume of air or liquid is injected in the epidural space, it is contained in a small pocket under pressure between the vertebral canal and the dura. This pocket acts as a cushion through which the spinal CSF pressure and its pulsatile waves are transmitted, with the dura acting as a movable membrane of a transducer.
CONCLUSION Leakage of CSF after a dural tap reduces the spinal CSF pressure and should also reduce the epidural pressure. In hypertensive encephalopathy there is an increase in CSF pressure, which should also increase the epidural pressure. Measurement of epidural pressure may distinguish between these two conditions. As stated by Wildsmith,” all epidural injections should be made slowly, especially when raised intracranial pressure is suspected. This may also apply to epidural injections in the immediate postpartum period where routine administration of ergot preparations may have produced an increase in the intracranial pressure.
References 1. Abouleish E. Postpartum hypertension and convulsion after oxytocic drugs. Anesth Analg 1976; 55: 813-815. 2. Ringrose C A D. The obstetrical use of ergot: A violation of the doctrine ‘Primum Non Notre’. Can Med Assoc J 1962; 87: 712-714. 3. Shah J L. Influence of cerebrospinal fluid on epidural pressure. Anaesthesia 1981; 36: 627-63 1. 4. Shah J L. Effect of posture on extradural pressure. Br J Anaesth 1984; 56: 1373-1376. 5. Shah J L, Veness A M. Epidural blood patch using a catheter. Diagnosis of an unrecognised dural tap. Anaesthesia 1985; 40: 1120-1123. 6. Okell R W, Sprigge J S. Unintentional dural puncture. A survey of recognition and management. Anaesthesia 1987; 42: 1110-l 113. 1. Coombs D W, Hooper D. Subarachnoid pressure with epidural blood ‘patch’. Regional Anesthesia 1979; 4: 3-6. 8. Usubiaga J E, Usubiaga L E, Brea L M, Goyena R. Effect of saline injections on epidural and subarachnoid space pressures and relation to postspinal anesthesia headache. Anesth Analg 1967; 46: 293-296. 9. Browning D J. Serious side effects of ergometrine and its use in routine obstetric practice. Med J Aust 1974; 1: 957-959. 10. Hilt H, Gramm H-J, Link J. Changes in intracranial pressure associated with extradural anaesthesia. Br J Anaesth 1986; 58: 676-680. 11. Wildsmith J A W. Extradural blockade and intracranial pressure (Editorial). Br J Anaesth 1986; 58: 579. 12. Fish S A, Morrison J C, Bucovaz E T, Wise W L, Whybrew W D. Cerebral spinal fluid studies in eclampsia. Am J Obstet Gynecol 1972; 112: 502-512. 13. Harrison G R. A model of the extradural space and a reappraisal of the extradural space pressure. Br J Anaesth 1987: 59: 1177-l 180. 14. Shah J L. May ‘extradural pressure be positive? (Abstract). Br J Anaesth 1990; 65: p. 280.
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SUMMA R Y. Half an hour after a normal delivery under epidural analgesia, a patient was given a top-up of 10 ml 0.25% bupivacaine for suture of a small vaginal tear. The patient developed severe headache, nausea and vomiting immediately after the top-up. Initially these symptoms were attributed to a complication of epidural analgesia. However, a raised epidural pressure led to a diagnosis of hypertensive encephalopathy.
Severe headache, nausea, vomiting and photophobia are common after an inadvertent dural puncture in a young parturient. These symptoms result from excessive loss of cerebrospinal fluid (CSF) from the dural rent, especially following straining during delivery. Headache, nausea and vomiting may also occur in hypertensive disease of pregnancy, especially after the use of ergot preparations.‘*’ A case is described where these symptoms occurred immediately after an epidural top-up and gave rise to difficulty in diagnosis.
sia was established at L2/3 interspace without difficulty, and 10 ml 0.25% bupivacaine produced good analgesia. After this her blood pressure remained normal and varied between 116/69 and 136/78 mm Hg. During labour, a small volume of urine passed at 06:OO had a trace of protein, and a catheter specimen of urine obtained at 09:OOshowed heavy proteinuria of + + + on dip stick testing. For the remainder of labour, two further 10 ml top-ups of 0.25% bupivacaine, given by the midwife, produced good analgesia. At 11:40 she had a spontaneous delivery of a live male infant weighing 3.70 kg. At delivery she received an intramuscular injection of 1 ml Syntometrine (0.5 mg ergometrine with 5 units of synthetic oxytocin). Her blood pressure soon after delivery was 155/83 mm Hg. 35 min after the delivery, her blood pressure prior to a top-up for suture of a vaginal tear was 166/85 mm Hg. She was given a 10 ml top-up of 0.25% bupivaCaine by the midwife, and immediately after the epidural injection she complained of severe frontal headache. She was nauseated and retched uncontrollably. Since the onset of her headache coincided with an epidural top-up, the on-call trainee obstetrician asked the author for an anaesthetic opinion. At 12:20, 5 min after the top-up, her blood pressure had risen to 170/95 mm Hg. She was extremely distressed with severe frontal headache, nausea and violent retching. She was conscious and cooperative, and did not show any signs of impaired cerebral function. There was no neck stiffness or papilloedema. Her reflexes appeared normal but at the time, being distressed, she was constantly moving her arms and legs, and it was difficult to elicit hyper-reflexia. She was able to move all her limbs. Aspiration of the epidural catheter was negative, and there was no evidence of an inadvertent dural tap.
CASE REPORT A 23-year-old primigravida was admitted to the labour ward at 01:OO in early labour. Her antenatal course was uneventful with an average blood pressure of 1IO/60 mm Hg, and no proteinuria or oedema. At 04:30 she received 100 mg pethidine (meperidine) and 25 mg promazine for analgesia. Because of slow progress, at 07:30 her labour was augmented with an infusion of Syntocinon (synthetic oxytocin devoid of the pressor-inducing effects of ergot derivatives). Half an hour later, at 08:OO she became distressed and requested epidural analgesia. During labour her blood pressure had been normal and there were no contraindications to epidural analgesia. Five minute blood pressure recordings using an automatic blood pressure monitor (Critikon Dinamap TM 1846SX) were started prior to establishing an epidural block. Blood pressure, recorded soon after a painful contraction, was 135/90 mm Hg and returned to 130/85 5 min later. At 08: 15 epidural analgeCorrespondence to: J. L. Shah, Department of Anaesthetics, Dudley Road Hospital, Birmingham B18 7QH, UK. 29
30
International Journal of Obstetric Anesthesia
The epidural pressure was measured using the epidural catheter as a manometer.3*4 To do this the patient was placed in the left lateral position, the epidural catheter held vertically, and the bacterial filter disconnected from the catheter to allow the fluid level in the catheter to descend. The vertical distance between the final level of the liquid meniscus and the lumbar puncture after allowing for the capillarity effect (with a 16G Portex catheter the capillarity effect is 2 cm HzO) gave an epidural pressure in this patient of 20 cm H,O, which is greater than normal.4 A presumptive diagnosis of severe pregnancy induced hypertension was made, an immediate intravenous injection of 5 mg diazepam given and the arterial pressure monitored. Over the next 3 h the blood pressure slowly declined from 170/95 to lSO/SS mm Hg without further intervention. She still complained of slight headache. Since her blood pressure was declining, it was decided to transfer her to the postnatal ward. The epidural catheter was removed and the puncture site dressed. Whilst being transferred to her bed, the patient had a grand ma1 seizure. She was treated immediately with intravenous diazepam, oxygen by a face mask, and intravenous infusion of chlormethiazole. Within a few minutes her blood pressure settled at 130/80 mm Hg. After the convulsion she had proteinuria of 1 to 2 + + for 3 h and a trace for a further 7 h. With treatment her condition improved over the next 20 h and she made an uneventful recovery. Both mother and baby were discharged home 3 days later in perfect health.
DISCUSSION Severe postpartum headache may occur with an inadvertent dural puncture, hypertension of pregnancy or a subarachnoid haemorrhage. Nausea, vomiting and retching may accompany the headache in all three conditions. An inadvertent dural tap may not be identified at the time of performing the epidural puncture,5*6 and becomes evident only when the patient develops postpartum headache. The onset of headache is variable, and may occur early if an excessive amount of CSF is lost during straining at delivery. The CSF pressure is reduced in patients suffering from post dural puncture headache.’ Since the CSF pressure directly affects the epidural pressure,3 it too should be decreased. Injection of saline has been used to relieve the post dural puncture headache.* In our patient, there was no evidence of dural puncture, the epidural pressure was high, and the headache had been precipitated by the injection of fluid into the epidural space. Syntometrine, which contains 0.5 mg ergometrine, is widely used to prevent postpartum haemorrhage.
Ergot preparations are known to cause severe vasoconstriction and a rise in blood pressure. Severe hypertension, cerebral oedema and convulsions have been reported after its use.l*’ In these reports, headache, nausea and retching preceded the convulsions. Like other reported cases,’ our patient developed hypertension after ergot administration in spite of having normal blood pressure throughout her pregnancy. The single raised pressure during labour was, at the time, attributed to painful contractions. Sudden onset of headache is characteristic of a subarachnoid haemorrhage. However, other signs of cerebral irritation would be expected. In severe cases the patient is semistuporous or drowsy, confused and irritable when roused. Our patient was alert and cooperative, with normal plantar reflexes and subarachnoid haemorrhage seemed unlikely. A significant feature in our patient was that the onset of headache coincided with an epidural top-up. Injection of fluid into the epidural space may compress the dural sac and cause a shift of CSF from the spinal to the cranial compartment and increase the intracranial pressure. l”*ll The lumbar epidural pressure in the immediate postpartum period is reported to be 13.1 f3.0 cm Hz04. The increased epidural pressure in our patient may have been secondary to an increased intracranial pressure which is known to occur in severe pre-eclampsia.” It seems likely that after the injection of Syntometrine (containing 0.5 mg ergometrine), our patient developed hypertension with a degree of hypertensive encephalopathy. The epidural top-up by producing a shift of CSF from the spinal to the intracranial compartment may have further increased her intracranial pressure and precipitated her symptoms. The initial diagnosis of pregnancy induced hypertension in this patient was based on severe headache associated with nausea, retching, high arterial pressure and a raised epidural pressure. However, the recognition of this disorder was delayed because the patient had normal blood pressure without proteinuria or oedema during pregnancy and a normal blood pressure during labour. The misconception that headache during or immediately after labour is commonly due to a complication of epidural analgesia may also have delayed the acceptance of pregnancy induced hypertension as the cause. The final diagnosis of pregnancy induced hypertension was only accepted when the patient had a convulsion. The primary treatment in this patient should have included antihypertensive therapy, which might have prevented the seizure. The patient was lightly sedated by the initial dose of diazepam which may have delayed the occurrence of convulsions. It has been suggested that the epidural pressure is not a single measurable entity, but a complex dynamic equilibrium of forces between the vertebral column and the dura.13 Various factors, including the move-
Severe headache following an epidural ‘top-up’
ment of CSF within the spinal dura and of the blood within the vertebral canal are known to affect the epidural pressure. However, it is the author’s opinion that provided the patient stays still, the epidural pressure is a close approximation of the prevailing spinal CSF pressure and can easily be measured with a simple manometer. It has recently been shown that a pressurised Macintosh balloon may not deflate in the epidural space. l4 It seems likely that when a small volume of air or liquid is injected in the epidural space, it is contained in a small pocket under pressure between the vertebral canal and the dura. This pocket acts as a cushion through which the spinal CSF pressure and its pulsatile waves are transmitted, with the dura acting as a movable membrane of a transducer.
CONCLUSION Leakage of CSF after a dural tap reduces the spinal CSF pressure and should also reduce the epidural pressure. In hypertensive encephalopathy there is an increase in CSF pressure, which should also increase the epidural pressure. Measurement of epidural pressure may distinguish between these two conditions. As stated by Wildsmith,” all epidural injections should be made slowly, especially when raised intracranial pressure is suspected. This may also apply to epidural injections in the immediate postpartum period where routine administration of ergot preparations may have produced an increase in the intracranial pressure.
References 1. Abouleish E. Postpartum hypertension and convulsion after oxytocic drugs. Anesth Analg 1976; 55: 813-815. 2. Ringrose C A D. The obstetrical use of ergot: A violation of the doctrine ‘Primum Non Notre’. Can Med Assoc J 1962; 87: 712-714. 3. Shah J L. Influence of cerebrospinal fluid on epidural pressure. Anaesthesia 1981; 36: 627-63 1. 4. Shah J L. Effect of posture on extradural pressure. Br J Anaesth 1984; 56: 1373-1376. 5. Shah J L, Veness A M. Epidural blood patch using a catheter. Diagnosis of an unrecognised dural tap. Anaesthesia 1985; 40: 1120-1123. 6. Okell R W, Sprigge J S. Unintentional dural puncture. A survey of recognition and management. Anaesthesia 1987; 42: 1110-l 113. 1. Coombs D W, Hooper D. Subarachnoid pressure with epidural blood ‘patch’. Regional Anesthesia 1979; 4: 3-6. 8. Usubiaga J E, Usubiaga L E, Brea L M, Goyena R. Effect of saline injections on epidural and subarachnoid space pressures and relation to postspinal anesthesia headache. Anesth Analg 1967; 46: 293-296. 9. Browning D J. Serious side effects of ergometrine and its use in routine obstetric practice. Med J Aust 1974; 1: 957-959. 10. Hilt H, Gramm H-J, Link J. Changes in intracranial pressure associated with extradural anaesthesia. Br J Anaesth 1986; 58: 676-680. 11. Wildsmith J A W. Extradural blockade and intracranial pressure (Editorial). Br J Anaesth 1986; 58: 579. 12. Fish S A, Morrison J C, Bucovaz E T, Wise W L, Whybrew W D. Cerebral spinal fluid studies in eclampsia. Am J Obstet Gynecol 1972; 112: 502-512. 13. Harrison G R. A model of the extradural space and a reappraisal of the extradural space pressure. Br J Anaesth 1987: 59: 1177-l 180. 14. Shah J L. May ‘extradural pressure be positive? (Abstract). Br J Anaesth 1990; 65: p. 280.
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