A nurse is assessing an elderly patient receiving palliative care who exhibits Cheyne-Stokes respirations. Which of the following characteristics should the nurse identify as indicative of this respiratory pattern?

The correct answer is Choice D

Choice A rationale: A 1-inch needle is typically used for intramuscular injections, not intradermal administration. Intradermal injections require a short, fine-gauge needle—usually ¼ to ⅝ inch in length and 25 to 27 gauge—to ensure accurate placement within the dermis. Using a longer needle increases the risk of injecting into subcutaneous tissue, which alters absorption and invalidates the test. Scientific technique demands precise needle selection based on anatomical depth and pharmacokinetics of the test substance.

Choice B rationale: A 20° angle is inappropriate for intradermal injections, which require a shallow angle of 5° to 15° to ensure deposition within the dermal layer. Angles greater than 15° risk penetrating into subcutaneous tissue, compromising test accuracy and absorption kinetics. The dermis is a narrow layer between the epidermis and subcutaneous fat, and precise angulation is critical for forming the characteristic wheal and ensuring localized immune response. Scientific technique mandates strict adherence to angle parameters.

Choice C rationale: The standard volume for a tuberculin skin test using purified protein derivative (PPD) is 0.1 mL, not 0.5 mL. Administering 0.5 mL would exceed the recommended dose, potentially causing excessive local reaction, invalid test results, and patient discomfort. The Mantoux method requires exact dosing to elicit a controlled immune response for accurate interpretation. Scientific protocol emphasizes precision in volume to maintain test validity and minimize adverse effects. Overdosing violates established guidelines.

Choice D rationale: Pinching or gently pulling the skin taut at the injection site stabilizes the dermal layer and facilitates correct needle placement. This technique ensures the needle enters at the proper angle and depth, allowing formation of a visible wheal, which confirms intradermal delivery. It also minimizes patient discomfort and prevents misplacement into deeper tissues. Scientific technique for intradermal injections prioritizes anatomical control and tactile feedback to optimize accuracy and diagnostic reliability.

The correct answer is Choice A. The client is receiving an oxygen concentration of 28%. Nasal cannulas can deliver oxygen at a flow rate ranging from 1 to 6 liters per minute (L/min), with

each additional liter increasing the fraction of inspired oxygen (FiO2) by 4%. Therefore, at 2 L/min, the client is receiving an oxygen concentration of 28%78.