Postpartum peripheral neuropathy due to vitamin B12 deficiency, potentially precipitated by nitrous oxide use

Abstract

Summary Neurological dysfunction which would concern the anaesthetist on labour ward is typically associated with neuraxial blocks. However, an appreciation of other causes is crucial. We present a case of peripheral neuropathy secondary to vitamin B12 deficiency, which highlights the importance of a thorough neurological examination, alongside an understanding of neurological pathophysiology. This is crucial for initiating appropriate referral, subsequent investigations and treatment. Neurological dysfunction secondary to vitamin B12 deficiency may be reversible, following prolonged rehabilitation, so prevention is the best approach, which may require modification of anaesthetic techniques. In addition, at‐risk patients should be screened and treated prior to nitrous oxide use, with alternative methods of labour analgesia advised in very high‐risk individuals. The incidence of vitamin B12 deficiency may increase in the future potentially linked to a rise in plant‐based diets, so this picture may be more commonly seen. Added vigilance by the anaesthetist is imperative.