A nursing preceptor is reviewing life expectancy in the twentieth century with a new nurse. The nurse should recognize that which of the following was most responsible for the dramatic increase in life expectancy during the twentieth century.

Choice A reason: Hypertension is a manifestation of increased intracranial pressure, as it reflects the body's attempt to maintain adequate cerebral perfusion pressure (CPP) and blood flow to the brain. CPP is the difference between the mean arterial pressure (MAP) and the intracranial pressure (ICP). When ICP rises, MAP must also rise to keep CPP constant and prevent cerebral ischemia. Hypertension is part of the Cushing's triad, which is a classic sign of increased ICP that also includes bradycardia and irregular respirations.

Choice B reason: Tinnitus is not a manifestation of increased intracranial pressure, as it does not affect the auditory system. Tinnitus is a ringing, buzzing, or hissing sound in the ears that can be caused by various factors, such as ear infections, noise exposure, medications, or aging. Tinnitus may be associated with other neurological conditions, such as Meniere's disease, acoustic neuroma, or multiple sclerosis, but not with increased ICP.

Choice C reason: Hypotension is not a manifestation of increased intracranial pressure, as it indicates a decrease in MAP and CPP, which can lead to cerebral ischemia and infarction. Hypotension can be caused by various factors, such as blood loss, dehydration, shock, or medications. Hypotension may worsen the outcome of increased ICP by reducing the oxygen and nutrient delivery to the brain.

Choice D reason: Tachycardia is not a manifestation of increased intracranial pressure, as it contradicts Cushing's triad. Tachycardia is an increase in heart rate that can be caused by various factors, such as anxiety, pain, fever, dehydration, or medications. Tachycardia may increase the oxygen demand and metabolic rate of the brain, which can exacerbate the effects of increased ICP.

Choice A reason: Planning medication doses to occur before meals is a good suggestion to improve the client's nutritional status. Myasthenia gravis is a neuromuscular disorder that causes weakness and fatigue of the voluntary muscles, especially those involved in chewing and swallowing. Taking anticholinesterase medications before meals can enhance muscle strength and coordination, and make it easier for the client to eat and avoid choking or aspiration.

Choice B reason: Restricting drinking fluids before and during meals is not a good suggestion to improve the client's nutritional status. Fluid intake is important for hydration and digestion, and should not be limited unless there is a medical reason, such as fluid overload or heart failure. Drinking fluids before and during meals can also help lubricate the food and prevent dryness or irritation of the mouth and throat.

Choice C reason: Increasing the amount of fat and carbohydrates in meals is not a good suggestion to improve the client's nutritional status. Fat and carbohydrates are sources of energy, but they can also increase the risk of obesity, diabetes, or cardiovascular disease if consumed excessively. A balanced diet that includes adequate protein, vitamins, minerals, and fiber is more beneficial for the client's health and well-being.

Choice D reason: Eating three large meals per day is not a good suggestion to improve the client's nutritional status. Eating large meals can be difficult and exhausting for the client with myasthenia gravis, as their muscle strength and endurance may decline over time. Eating smaller and more frequent meals can help maintain the energy level and prevent fatigue or hunger.