Obstetric anaesthetists may be involved in the care of women who present with a previous history of intracranial tumour, or in whom a brain tumour is diagnosed for the first time during pregnancy, labour and delivery, or in the postpartum period.
Problems and special considerations
Previous history of tumour
Women with a past history of a brain tumour may have residual neurological impairment, as for a past history of neurological trauma. A small number of women have residual tumour left, and this may be affected by the pregnancy. There may be a shunt to maintain normal cerebrospinal fluid (CSF) pressures. Generally, these shunts drain from the brain into the peritoneal cavity; however, some drain CSF around the spinal cord into the peritoneum. The latter may be placed in the lumbar region and thus cause a problem if regional block is to be considered (see Chapter 122, Idiopathic intracranial hypertension). The risk of introducing infection at the time of a regional block is very small but may be a deterrent to regional block in these women. Most patients will be particularly anxious about the effects of both regional and general anaesthesia on their neurological function.
Tumour diagnosed during pregnancy
Particular problems may be related to:
• The nature of the tumour
• The treatment the patient is receiving, e.g. steroids or anticonvulsants
• The presence of raised intracranial pressure (ICP), its severity and the associated risk of coning
• The effect of pushing in the second stage of labour on ICP and the tumour
• The presence of any other medical problems
• The risks of regional analgesia or anaesthesia and general anaesthesia
Tumour manifesting itself in the peripartum period
The woman may present with neurological signs or symptoms that may be related to the position of the tumour or to the development of raised ICP. The obstetric anaesthetist may be asked to see the woman, particularly if she has had a regional anaesthetic.
Presentation may be with altered consciousness, focal signs, a convulsion or a headache. The differential diagnosis includes eclampsia, epilepsy, meningitis, posterior reversible encephalopathy syndrome, cerebral venous thrombosis and postdural puncture headache. The headache associated with raised ICP is usually present when the patient is supine and, unlike postdural puncture headache, does not worsen on standing; typically it is made worse by stooping, coughing and straining. The associated symptoms and signs of photophobia, vomiting and neck stiffness may be present both in raised ICP and following dural puncture.
Management options
If a tumour has been diagnosed during pregnancy, the obstetric anaesthetist should be consulted about the management of the labour and the provision of regional analgesia/ anaesthesia to help minimise the stress of labour and delivery. The benefits of regional techniques in these patients must be balanced against the risk of dural puncture and of coning. Decision making should take into account the size and location of the tumour, the presence of mass effect, any clinical or radiological evidence of raised ICP and the potential risks of general anaesthesia. The advice of a neurologist or neurosurgeon should also be sought. If epidural analgesia is indicated, a senior anaesthetist should be involved.
Slow, titrated boluses or a continuous infusion of epidural solution is advisable to reduce the sharp rise in ICP that may result from compression of the dural sac with injection. Pushing in the second stage should be minimised, to reduce the possibility of bleeding into the tumour or acute increases in ICP. If the patient is suffering from a significant increase in ICP and the obstetrician advises urgent delivery, caesarean section under general anaesthesia may be the technique of choice. General anaesthesia may need to be modified to give a ‘neuro’ anaesthetic that would minimise raised ICP at the time of induction of and emergence from anaesthesia. Nausea and vomiting should be well controlled. It is important to remember that decreased arterial partial pressure of carbon dioxide from the normal value in pregnancy (approximately 4 kPa) in the mother will reduce placental perfusion and this may compromise the fetus.
When new headaches, convulsions or other neurological symptoms and signs present in the peripartum period, it is easy to assume more common conditions such as postdural puncture headache and eclampsia, rather than think of intracranial tumour. A careful history and examination (where appropriate by a neurologist) is important in reaching the correct diagnosis, with cranial imaging as appropriate. Once diagnosed, treatment is as for any non-pregnant patient.
The majority of women who have had previous intracranial tumours are entirely normal and have no residual problems. Neurological/neurosurgical advice will be necessary to establish whether the pregnancy will affect any residual tumour.
Key points
• In women who have or have had an intracranial tumour, regional analgesia is usually indicated during labour, but an accidental dural puncture may be catastrophic; thus the decision should depend on the individual features of each case.
• Underlying intracerebral pathology should always be considered when new symptoms or signs present postpartum.
• A neurologist should be consulted if in doubt.
Further reading
Anson JA, Vaida S, Giampetro DM, McQuillan PM. Anesthetic management of labor and delivery in patients with elevated intracranial pressure. Int J Obstet Anesth 2015; 24: 147-60.
Leffert LR, Schwamm LH. Neuraxial anesthesia in parturients with intracranial pathology: a comprehensive review and reassessment of risk. Anesthesiology 2013; 119: 703-18.
Verheecke M, Halasaka MJ, Lok CA, et al. Primary brain tumours, meningiomas and brain metastases in pregnancy: report on 27 cases and review of literature. Eur J Cancer 2014; 50: 1462-71.
Wang LP, Paech MJ. Neuroanesthesia for the pregnant woman. Anesth Analg 2008; 107: 193-200.