Management of Refractory Anaphylaxis: An Overview of Current Guidelines.

In this review, we compare different refractory anaphylaxis (RA) management guidelines focusing on cardiovascular involvement and best practice recommendations, discuss postulated pathogenic mechanisms underlining RA and highlight knowledge gaps and research priorities. There is a paucity of data supporting existing management guidelines. Therapeutic recommendations include the need for the timely administration of appropriate doses of aggressive fluid resuscitation and intravenous (IV) adrenaline in RA. The preferred second-line vasopressor (noradrenaline, vasopressin, metaraminol and dopamine) is unknown. Most guidelines recommend IV glucagon for patients on beta-blockers, despite a lack of evidence. The use of methylene blue or extracorporeal life support (ECLS) is also suggested as rescue therapy. Despite recent advances in understanding the pathogenesis of anaphylaxis, the factors that lead to a lack of response to the initial adrenaline and thus RA are unclear. Genetic factors, such as deficiency in platelet activating factor-acetyl hydrolase or hereditary alpha-tryptasaemia, mastocytosis may modulate reaction severity or response to treatment. Further research into the underlying pathophysiology of RA may help define potential new therapeutic approaches and reduce the morbidity and mortality of anaphylaxis.