Question: My 78-year-old dad is considering hip replacement. I am concerned that general anesthesia might cause his mental state to deteriorate. My mother was never the same after surgery. She had hallucinations and paranoia, signs that my dad sometimes shows already. What are the dangers to the elderly in general anesthesia?

Answer: Most older people who undergo hip (or other major joint) replacement are glad they did. Arthritis might significantly limit an older person’s mobility. An older person with severe arthritis in the hip might no longer be able to walk, exercise, or have intercourse comfortably. Blood pressure and blood glucose might be more difficult to control. Muscle weakness and pressure sores might develop in extreme cases. Hip surgery could possibly change your father’s life for the better.

It sounds as if your mother had delirium after her surgery. Delirium is a sudden alteration in mental status, which is seen in at least 1/6, and perhaps 1/3 of adults over the age of 65 who are hospitalized. Older adults who are cognitively impaired (problems with their memory) and who are sensory impaired (especially from low vision) are particularly at risk. The medical and psychosocial stresses of hospitalization cause the confusion. Examples of these stresses include fever, sleep deprivation, immobilization, unfamiliar environment, medicines, chemical abnormalities, infection, stroke, alcohol withdrawal, urinary retention, and fecal impaction. Even if spinal anesthesia is used, as is common for hip surgery, other stresses in the hospitalized environment can cause delirium. Although most people do return to normal, it can take up to eight weeks after discharge from the hospital to return to the pre-hospitalization state.

The risk of delirium in the hospital can be reduced by frequently re-orienting the individual, avoiding unnecessary instrumentation such as urinary catheters, monitoring medicines carefully, ensuring adequate nutrition and supplementing meals with frequent snacks to prevent dehydration or malnutrition, and having the individual get out of bed early in the hospital stay. Making sure that the patient has his or her glasses and hearing aid is important to keep in tune with the environment. A quiet hallway, relaxation tapes, and a cup of warm milk or herbal tea before bedtime are better than using a sleeping pill, which might contribute to confusion.