When positioned properly, the tip of a central venous catheter should lie in the:

Correct Answer: A

Rationale: A central venous catheter (CVC) is inserted to deliver fluids, medications, or nutrition directly into large veins near the heart, and its tip placement is critical for safety and efficacy. The superior vena cava (Choice A) is the correct location, specifically near its junction with the right atrium but without crossing into it, ensuring rapid dilution of infused substances into central circulation. The basilica vein (Choice B) is a peripheral vein in the arm, unsuitable for a CVC's central purpose. The jugular vein (Choice C) and subclavian vein (Choice D) are common insertion sites, but the catheter's tip must advance beyond these entry points to the superior vena cava for proper function. Misplacement (e.g., too far into the right atrium) risks arrhythmias or perforation, while too proximal a position reduces effectiveness. Imaging (e.g., chest X-ray) confirms placement in the superior vena cava, balancing efficacy and safety. This anatomical precision makes Choice A the correct answer, reflecting standard practice in critical care nursing.

Correct Answer: A

Rationale: Blunt chest trauma from a motor vehicle accident can compromise airway, breathing, or circulation (ABCs), the nurse's top priorities. Assessing the client's airway (Choice A) is first because obstruction (e.g., from blood, swelling, or foreign objects) or injury (e.g., pneumothorax) threatens life within minutes. Signs like stridor, cyanosis, or absent breath sounds demand immediate actione.g., suctioning or intubation. Pain relief (Choice B) is vital but secondary, as unrelieved pain won't kill instantly, unlike airway loss. Encouraging deep breathing and coughing (Choice C) risks worsening injuries like rib fractures or flail chest if airway isn't secured. Splinting the chest (Choice D) aids breathing but assumes airway patency. For example, a tracheal deviation from tension pneumothorax detected during airway assessment takes precedence over pain. ABC prioritization ensures survival, making Choice A the correct first step.

Correct Answer: A

Rationale: Waking from sleep due to abdominal pain involves the body's arousal system responding to internal signals. 'Stimuli from peripheral organs to the RAS' explains this: the reticular activating system (RAS) in the brainstem regulates sleep-wake transitions, and visceral pain (e.g., from gastric distension) sends afferent signals via the vagus nerve to the RAS, triggering arousal. Choice B, 'stimuli to the wake center in the cerebral cortex,' is vague; no specific 'wake center' exists, and cortical activation follows RAS stimulation, not direct peripheral input. Choice C, 'messages from chemoreceptors to the brain,' applies to respiratory stressors (e.g., low oxygen), not abdominal pain, which lacks a chemical trigger like hypoxia. Choice D, 'messages from baroreceptors to the spinal cord,' relates to blood pressure regulation (e.g., carotid sinus), not visceral pain perception. For instance, appendicitis pain activates nociceptors, relaying signals through spinal pathways to the RAS, overriding sleep's inhibition. This aligns with sleep physiology, where the RAS filters stimuli, awakening the individual only for significant threats, making Choice A correct.

Correct Answer: D

Rationale: Diet influences sleep via neurotransmitter and blood sugar effects. 'A carbohydrate snack' promotes sleep by raising tryptophan levels, a serotonin and melatonin precursore.g., a banana or crackers 1-2 hours before bed stabilizes glucose, easing sleep onset. 'One cup of hot chocolate' has caffeine (e.g., 5-20 mg), a stimulant delaying sleep, despite warmth's relaxation. 'Three glasses of red wine' sedates initially but disrupts REM sleep latere.g., alcohol metabolism at 3 a.m. causes awakeningsper sleep studies. 'A high-protein snack' , like turkey, has tryptophan but digestion (e.g., tyrosine release) can stimulate, not sedate. Nursing, per Taylor, favors carbs for their insulin-mediated tryptophan boost, avoiding stimulants or heavy meals. Choice D is the correct, evidence-based recommendation.

Correct Answer: B

Rationale: Cataplexy, tied to narcolepsy, involves muscle weakness triggered by emotions. 'Sudden loss of motor tone that may cause the person to fall asleep; usually experienced during a period of strong emotion' is correcte.g., laughter drops a patient's jaw or knees, lasting seconds, per AASM. Choice A, 'irresistible urge to sleep,' is narcolepsy's sleep attacks, not cataplexye.g., no muscle loss. Choice C, 'nightmare or vivid hallucinations,' fits hypnagogic events, not cataplexy's waking state. Choice D, 'skeletal paralysis during transition,' describes sleep paralysis, not emotion-driven cataplexye.g., no falling asleep. A nurse might see a patient slump during joy, per Taylor's neurology. Choice B precisely defines this feature.