What is the main complication of Antisera?

Appeared in: MP CHO - 2022

Explanation

Anaphylactic reaction is the most severe and immediate complication of antisera, which are often derived from non-human sources (heterologous serum).
It is a Type I hypersensitivity reaction, mediated by IgE antibodies, that occurs within minutes of exposure.
Key features include life-threatening respiratory distress (bronchospasm, laryngeal edema) and cardiovascular collapse (hypotension, shock).
The rapid onset and high mortality risk make it the primary concern during antisera administration, distinguishing it from other, less severe reactions.

Option A: Rashes are a common symptom, but they are typically associated with serum sickness, a delayed (Type III) hypersensitivity reaction that is less severe than anaphylaxis.
Option B: Fever is also a hallmark of serum sickness, a delayed and generally self-limiting complication. It is not the most critical or life-threatening reaction.
Option D: Cardiac arrest is a potential terminal event resulting from untreated anaphylactic shock. It is a consequence of the primary complication (anaphylaxis), not the complication itself.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Complications of Antisera Administration as background academic context rather than a clinical decision trigger.
Before administering any foreign serum (antisera, antitoxin), a sensitivity test (e.g., intradermal injection of a diluted dose) is crucial to identify sensitized individuals.
Nurses must have an emergency kit with Adrenaline (Epinephrine) 1:1000 solution readily available at the bedside whenever administering antisera.
Patient monitoring is critical. The patient should be observed for at least 30 minutes post-injection for any signs of an immediate reaction.

How to Approach the Question

First, understand the question is asking for the 'main' complication. This implies looking for the most serious, life-threatening, or characteristic issue.
Analyze the options in terms of severity and immediacy. Antisera are foreign proteins, which carry a risk of severe allergic reactions.
Evaluate 'Rashes' and 'Fever'. These are common but generally not life-threatening symptoms.
Evaluate 'Anaphylactic reaction'. This is a known, rapid, and potentially fatal systemic allergic reaction.
Evaluate 'Cardiac arrest'. While extremely serious, consider if it's a primary event or a consequence of something else. In this context, it's a result of shock from anaphylaxis.
Conclude that the anaphylactic reaction is the primary, most critical complication that directly results from the administration of the antisera.

Concept Tested & Keywords

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E6 Parks TextBook of Preventive & Social Medicine part 1 — Subpart A (pp 26-201 of 604) p. 114-116

E6 Nursing Brunner Adult Health 3SA Vol 1 Part 3 p. 124-126

Practise the full MP CHO - 2022

Attempt every question from this paper in a timed mock, then review the full solution for each one.