A nurse is caring for a client who develops a pulmonary embolism.
Which of the following interventions is the priority for the nurse to take?

Choice A rationale

Epinephrine is an adrenergic agonist and a potent vasoconstrictor, primarily used to treat severe allergic reactions (anaphylaxis) and cardiac arrest by stimulating alpha and beta receptors. It would not reverse the anticoagulant effects of warfarin, which acts by inhibiting vitamin K epoxide reductase in the coagulation cascade. Its mechanism of action is unrelated to reversing excessive anticoagulation.

Choice B rationale

Protamine sulfate is the specific antidote for heparin overdose, not warfarin. Protamine is a highly basic protein that forms a stable, inactive complex with the highly acidic heparin molecule, thereby neutralizing its anticoagulant effect. It has no effect on the mechanism of action of warfarin, which interferes with vitamin K-dependent clotting factors synthesis.

Choice C rationale

Atropine is an anticholinergic (parasympatholytic) agent used to increase heart rate in cases of symptomatic bradycardia by blocking the effects of acetylcholine at muscarinic receptors. It does not interact with the clotting cascade or the pharmacodynamics of warfarin, which requires replacement of the necessary clotting factors or its cofactor.

Choice D rationale

Vitamin K (Phytonadione) is the essential cofactor for the synthesis of coagulation factors II, VII, IX, and X in the liver, which are inhibited by warfarin. Administering Vitamin K bypasses the warfarin-induced block, promoting the production of functional clotting factors and thus reversing excessive anticoagulation, which is reflected by a prolonged International Normalized Ratio (INR) (therapeutic range 2.0-3.0).

Choice A rationale

Applying cold packs, or cryotherapy, is primarily indicated for acute soft tissue injuries to induce vasoconstriction, thereby decreasing local blood flow, metabolism, and inflammation, which reduces pain and swelling. For chronic or recurring lower back pain prevention, heat is often more effective, as it promotes vasodilation, increasing blood flow to relax muscles and reduce stiffness, making cold less suitable as a frequent preventative strategy.

Choice B rationale

Prolonged static postures, like sitting, increase intradiscal pressure and muscle tension in the lumbar region, leading to muscle fatigue and reduced blood flow to the supporting structures, which exacerbates back pain. Regular movement and changing positions is crucial to maintain flexibility, promote circulation, and distribute mechanical stress across different structures, minimizing sustained strain on the spinal ligaments and discs.

Choice C rationale

Sleeping on a mattress that is too soft fails to provide adequate support for the spine's natural curvature (lumbar lordosis), allowing the trunk to sink, which can lead to spinal misalignment and increased strain on the back muscles and ligaments. A medium-firm mattress is generally recommended to maintain proper spinal alignment during sleep, which reduces mechanical stress and prevents morning stiffness and pain.

Choice D rationale

Asking for help when moving clients ensures the nurse can use proper body mechanics, which involves keeping the load close to the body, maintaining a wide base of support, and lifting with the legs, not the back. This principle minimizes the mechanical stress and sheer forces applied to the intervertebral discs and paraspinal muscles, significantly lowering the risk of acute muscle strains or chronic cumulative trauma to the lumbar spine.

Choice E rationale

Partial sit-ups with the knees bent strengthen the abdominal and oblique muscles, which are key components of the body's core musculature. A strong core acts as a stabilizer for the lumbar spine, increasing intra-abdominal pressure to support the vertebral column and reducing the load and mechanical strain on the lower back structures during movement and daily activities, thereby preventing injury recurrence.