[Perioperative aspects of anaphylaxis]

Anaphylaxis is a generalized, severe, life-threatening reaction, mostly with an allergic origin. Triggers are usually drugs, insect bites, poisons, contrast material and food. It is caused by various mediators (histamine, prostaglandins, leukotrienes etc.) released from mast cells, basophilic granulocytes. Histamine plays a central role in its creation. Immediate recognition and specific treatment instantaneously are essential for successful treatment. In severe conditions, the clinical features are very similar, regardless of their allergic/non-allergic origin. The incidence can vary over time and between patient populations. Its incidence is extremely variable, approximately 1/10 000 anaesthesia. Most studies cite neuromuscular blocking agents as the most common causative factor. In England, the results of the 6th National Audit Project revealed that the most common causes were antibiotics (1/26 845), followed by neuromuscular junction blocking drugs (1/19 070), chlorhexidine (1/127 698), and Patent Blue paint (1/6863). It occurs within 5 minutes in 66% of cases, 6-10 minutes in 17%, 11-15 minutes in 5%, 16-30 minutes in 2%, but usually within 30 minutes. Antibiotic allergy is a growing problem, especially to teicoplanin (16.4/100 000) and co-amoxiclav (8.7/100 000). The risk of anaphylactic shock should not be a determining factor in choosing the type of muscle relaxant drug. The patient's anaesthesia classification, physical condition, obesity, use of beta-blockers and ACE inhibitors influence the clinical characteristics. The initial symptoms can be extremely varied in terms of the effectiveness of the treatment, early recognition and commencement of therapy are the keys to success. Asking about a preoperative allergy history can reduce the risk and incidence of anaphylaxis. Orv Hetil. 2023; 164(22): 871-877.

The frequency of allergic reactions to the triple viral vaccine in 94 patients with egg allergy

Introduction: Vaccination is the most effective public health intervention of all times, reducing the death and morbidity rates derived from multiple infectious diseases. In many cases, the administration and reception of vaccines is delayed due to the fear of allergic reactions; this is frequent among patients with allergy to egg who need the triple viral vaccine. Objective: To evaluate the frequency of reactions after the administration of triple viral vaccine (Measles, Mumps and Rubella, MMR) in an egg-allergic population. Materials and methods: We conducted a multi-center retrospective study (2014-2016) including patients with egg allergy who visited an allergology center and required the administration of the triple viral vaccine. Results: A total of 94 patients met the selection criteria. From these patients, 68.2% had cutaneous symptoms, 22.3% had an anaphylactic reaction, 5.3% had gastrointestinal symptoms, and 4.2% had respiratory egg-related symptoms. Regardless of the severity of their reaction to egg, all patients received the triple viral vaccine and in 100% of the cases, it was well tolerated. Conclusion: Although egg allergy is common in childhood, the risk of allergic reactions during the MMR vaccination in this population was similar to that in the general population, therefore, its use should not be deferred even in patients with a history of severe egg-related allergic reactions.

Methylene blue for clinical anaphylaxis treatment: a case report

CONTEXT AND OBJECTIVE

Nitric oxide has a pathophysiological role in modulating systemic changes associated with anaphylaxis. Nitric oxide synthase inhibitors may exacerbate bronchospasm in anaphylaxis and worsen clinical conditions, with limited roles in anaphylactic shock treatment. The aim here was to report an anaphylaxis case (not anaphylactic shock), reversed by methylene blue (MB), a guanylyl cyclase inhibitor.

CASE REPORT

A 23-year-old female suddenly presented urticaria and pruritus, initially on her face and arms, then over her whole body. Oral antihistamine was administered initially, but without improvement in symptoms and signs until intravenous methylprednisolone 500 mg. Recurrence occurred after two hours, plus vomiting. Associated upper respiratory distress, pulmonary sibilance, laryngeal stridor and facial angioedema (including erythema and lip edema) marked the evolution. At sites with severe pruritus, petechial lesions were observed. The clinical situation worsened, with dyspnea, tachypnea, peroral cyanosis, laryngeal edema with severe expiratory dyspnea and deepening unconsciousness. Conventional treatment was ineffective. Intubation and ventilatory support were then considered, because of severe hypoventilation. But, before doing that, based on our previous experience, 1.5 mg/kg (120 mg) bolus of 4% MB was infused, followed by one hour of continuous infusion of another 120 mg diluted in dextrose 5% in water. Following the initial intravenous MB dose, the clinical situation reversed completely in less than 20 minutes, thereby avoiding tracheal intubation.

CONCLUSION

Although the nitric oxide hypothesis for MB effectiveness discussed here remains unproven, our intention was to share our accumulated cohort experience, which strongly suggests MB is a lifesaving treatment for anaphylactic shock and/or anaphylaxis and other vasoplegic conditions.