When administering ear drops to a 2-year-old, the nurse:

Choice A rationale

An intradermal injection is administered into the dermis, the layer of skin directly beneath the epidermis. A 15-degree angle ensures the needle enters superficially, creating a small wheal as the medication is deposited. This shallow angle minimizes penetration into subcutaneous tissue, which is crucial for proper antigen-antibody reactions in allergy testing or tuberculosis screening.

Choice B rationale

A 90-degree angle is used for intramuscular injections, where the medication is delivered deep into muscle tissue. This angle allows for rapid absorption due to the rich vascular supply of muscle, but it would cause excessive penetration and potential systemic absorption if used for an intradermal injection, negating its diagnostic purpose.

Choice C rationale

A 45-degree angle is typically used for subcutaneous injections, delivering medication into the adipose tissue layer beneath the dermis. This angle is too deep for an intradermal injection and would result in the medication being absorbed systemically rather than remaining in the dermal layer for localized diagnostic reactions.

Choice D rationale

A 30-degree angle is also too steep for an intradermal injection. While less deep than a 45-degree angle, it still risks penetrating beyond the dermis into the subcutaneous tissue. The goal of an intradermal injection is to deposit the substance within the highly specific dermal layer to elicit a localized, measurable response.

Choice A rationale

Determining areas of tenderness is typically done through palpation, which should follow auscultation to avoid altering bowel sounds. Performing palpation first could elicit guarding or muscle rigidity, making subsequent auscultation less accurate and potentially increasing patient discomfort.

Choice B rationale

Auscultation precedes percussion and palpation of the abdomen to ensure that bowel sounds are not artificially stimulated or inhibited. Mechanical manipulation of the abdomen through percussion and palpation can alter the frequency and character of bowel sounds, leading to inaccurate assessment of intestinal motility.

Choice C rationale

While patient comfort is important, the primary reason for the sequence of abdominal assessment is scientific accuracy. Manipulating the abdomen prior to auscultation can stimulate peristalsis, creating false-positive bowel sounds or increasing existing ones, thus obscuring the true baseline activity.

Choice D rationale

Distortion of vascular sounds like bruits and hums is less likely to be significantly affected by percussion and palpation compared to bowel sounds. Vascular sounds originate from blood flow dynamics, which are not as readily influenced by external mechanical manipulation as the peristaltic activity of the intestines.