Neuraxial analgesia and anaesthesia are well established and widely used in obstetrics. Serious neurological complications very rare, though early recognition is vital to reduce permanent morbidity due to two potential complications – vertebral canal haematoma and epidural abscess (detection and intervention within 12 hours has been suggested as the window to prevent permanent neurological disability).
NAP 3 (National Audit Project 3) identified just one of either of these complications in an obstetric patient in the UK in the 12 month observation period, but identified delays in recognition of, and appropriate understanding of the significance of, prolonged or new leg weakness as a cause of avoidable harm. It also suggested that difficulties with the inter-departmental referral process for these patients may be responsible for delays and additional harm.
There is no existing national guidance that applies to monitoring motor function following neuraxial block in obstetric patients. Local guidelines at Kingston Hospital reflect the NICE guidelines in recommending hourly sensory assessment of patients with epidurals.
A survey of obstetric anaesthetic leads in the UK (see journal club November 2018) found that local protocols for neurological monitoring, and referral and escalation, were frequently absent or varied widely between departments.
Aims of Guidance
To make recommendations on the monitoring of recovery from neuraxial block in obstetric patients and the escalation of patients with delayed recovery from or new symptoms after neuraxial block.
To prevent serious neurological morbidity.
The scope of the guidance was limited to monitoring and managing recovery from neuraxial block, but excluded acute complications. Neuraxial blocks were defined as spinal, epidural or CSE. Antenatal, labour, delivery or postnatal indications were all included.
- Anaesthetist to be alerted if woman receiving epidural analgesia cannot perform a straight leg raise
- Straight leg raise should be monitored hourly, in addition to the hourly sensory monitoring recommended by NICE
- Anaesthetist to be alerted if woman cannot perform a straight leg raise 4 hours after receiving spinal anaesthetic or epidural top-up for procedure
- The Bromage scale is recommended for more detailed assessment of motor block e.g. to monitor recovery from persistent block
- Women to be advised regarding expected resolution of their block and encouraged to alert staff if this does not occur
- All maternity units should have a policy to guide escalation where indicated, based on local services and referral pathways
- A policy should also exist for managing post-partum women who present with neurological deficits following discharge
There was agreement that obtaining an out-of-hours MRI could cause delay to management as this would require neurosurgical referral and transfer to St George’s. This was agreed as an area where departmental policies could be improved.
It was felt by some that assessment of motor function is being assessed though may not be being appropriately documented in many cases. In order for this to change it may be necessary to change the forms used by recovery and midwifery staff for the documentation of observations.
Summary by Dr D Baily. Journal Club Meeting 5 March 2020.