Background and Goal of Study: Feared infectious complications of central neuraxial blocks (CNB) are spinal or intracranial abscess. Due to the rarity of these complications, the characteristics of patients, symptoms, treatment and outcome are not clearly described. 
Materials and Methods: A systematic literature search was performed in three databases (Medline, Embase and the Cochrane Library) for reports of spinal and intracranial abscess associated with CNB. Patient characteristics, symptoms, risk factors and neurological outcome were analysed. 
Results and Discussion: The search yielded 667 articles, of which 137 articles were reviewed; 254 patients with spinal abscess (SA) and 3 patients with intracranial abscess (IA) were reported. SA occurred predominantly after epidural anaesthesia (83.0%). The majority of reported cases were related to chronic pain treatment (34.7%). In patients with SA, clinical factors associated with persistent neurological deficit were male sex and severe motor deficit prior to treatment (adjusted odds ratio [aOR] 3.1, 95% CI 1.3 - 7.3; p = 0.012 and aOR 3.7, 95% CI 1.2 – 11.4; p = 0.023, respectively). IA occurred in three females; two cases after spinal anaesthesia and one case after epidural anaesthesia. 
Conclusion(s): Patients can experience spinal or intracranial abscess after CNB. Caution should be taken when interpreting the results of this review, since publication bias, selection bias and underreporting of complications may have influenced the results, however we believe that the information of this review is helpful in understanding rare severe complications of CNB. Based on the results we can conclude that abscesses associated with CNB often occur when patients are out of the scope of the anaesthesiologists work field. In patients with pain as isolated symptom, conservative management may be indicated, provided that continuous patient monitoring is guaranteed. Since diverse details were encountered during analysis, we want to accentuate that uniform registries are needed to identify relevant risk factors and also to establish a more accurate estimate of the incidence of serious complications of CNB.

Systematic review of spinal and intracranial complications after central neuraxial blocks for perioperative and obstetric anaesthesia and analgesia. Part II: abscess