Total spinal anaesthesia following obstetric neuraxial blockade: a narrative review

Total spinal anaesthesia (TSA) is an emergency caused by high neuraxial blockade. It is a recognised complication of all neuraxial techniques in obstetric anaesthesia. Its incidence and outcomes have not been evaluated. There is compelling evidence that TSA continues to be a problem in contemporary practice, having the capacity to cause significant morbidity and mortality if not recognised early and promptly treated. This review based on a literature search aims to clarify the epidemiology of TSA, summarise its pathophysiology, and identify risk factors and effective treatments.

We performed a literature search using PubMed, Web of Science and Google Scholar databases using specified search terms for materials published using search terms. For each case, the type of block, the difficulty of the procedure, the dose of local anaesthetic, positivity of aspiration before and after the event, maternal outcome, Apgar score, onset of symptoms, cardiorespiratory and neurological manifestations, cardiorespiratory support employed, admission to an intensive care unit, cardiac arrest events and duration of mechanical ventilation were extracted.

A total of 605 cases were identified, of which 51 were sufficiently detailed for analysis. Although TSA is described after all neuraxial techniques, spinal after epidural was a particular concern in recent reports. Respiratory distress was universal but apnoea was not. The onset of apnoea was variable, ranging from 1 to 180 min. Hypotension was not invariable and occurred in approximately half of cases. Multiple fatalities and neurological injuries were reported, often in under-resourced areas when providers were not skilled in airway management or when recognition and intervention were delayed. In the most recent reports good outcomes were achieved when effective treatments were rapidly provided.

The available literature confirms that TSA remains an active clinical problem and that with prompt recognition and treatment good outcomes can be achieved. This requires anticipation and preparedness in all clinical areas where neuraxial techniques are performed.