Colonoscopy sedation not same as surgery
DEAR DR. ROACH: Your column regarding cognitive decline after surgery suggested careful consideration prior to elective surgery. Does this advice apply to screening colonoscopies? Since for it’s done for screening and there is no indication of any problem, does the risk outweigh the benefits for a patient 65 or older? — K.B.
ANSWER: The risk of cognitive decline after colonoscopy is very low. I could not find any data suggesting a significant risk of long-term changes to thinking or memory from the sedation or the procedure.
The sedation used for colonoscopy is very different from general anesthesia. While some anesthetic agents may have greater risk for cognitive decline than others, the risk for the sedatives in colonoscopy is very small.
There are risks to a screening colonoscopy. The most serious is a perforation of the colon, but bleeding and infection are other, rare risks. The preparation can cause imbalances in the salt levels of the blood. The risk of a serious complication after colonoscopy is less than 3 per 1,000 people. The benefits of early detection of colon cancer greatly outweigh the risks of a complication for nearly all healthy people between 50 and 75, and there are some recommendations to start earlier (at 45) or continue screening even older.
DEAR DR. ROACH: I am a 78-year-old woman. How can I get rid of the constant pain from the neuropathy caused from the shingles that I had four months ago? It is constant, sometimes feeling like menstrual cramps, but I also have intermittent stabs that feel like an ice pick stabbing in my pelvis. I have heard that it can last a year or even a lifetime. I was prescribed gabapentin at 100 mg, three times a day and 33 ml medical marijuana drops under my tongue twice a day, but I wish I knew that there could be an end to this. — A.C.S.
ANSWER: Shingles, caused by the recurrence of the chickenpox virus, damages the nerves (“neuropathy”), in some causes an extremely painful sensation. It is usually described as burning, but it may have other qualities such as you are describing.
It’s better to prevent shingles than to treat, as the treatments are only partially effective. The older a person is, the greater the likelihood of neuropathy (this type of neuropathy is called post-herpetic neuralgia) and tends to last.
Gabapentin (Neurontin) is a commonly used treatment for painful post-herpetic neuralgia, but I often see people using far less gabapentin than is effective. In the trial that got gabapentin indicated for PHN, the goal was to get trial subjects to a dose of 1,200 mg three times daily. My experience is that gabapentin starts to become effective in most at a dose of 300 mg three times daily, and most people can tolerate 900 mg three times daily if the dose is raised slowly, over months. Side effects of sedation limit the usefulness of gabapentin. Pregabalin (Lyrica) is easier to titrate to an effective dose, but it’s expensive. Older drugs, such as amitriptyline, may also help. A pain management specialist has expertise in treating PHN.
Cannabis-based medications are slightly better than placebo in treating chronic neuropathic pain. A review found that 21 percent of people had significant pain relief with cannabis-based medicines, compared with 17 percent using placebo. However, 61 percent noted nervous system adverse effects, compared with 29 percent of placebo. Psychiatric disorders occurred in 17 percent of the cannabis group and 5 percent of the placebo group.
(Roach is a columnist for the North American Press Syndicate. Write to him at 628 Virginia Drive, Orlando, FL 32803.)