You didn't really give enough detail for me to understand why you are considering tonsils/adenoids surgery for a sleep problem. This may be night terrors or some other issue. Or is there something you did not mention like apnea or continued ear/throat infections?
Anyway, I want to give my story because, while USUALLY this kind of surgery is just fine and can improve many issues, we have lived with a 5 year--so far--nightmare from it and my daughter may suffer for the rest of her life.
She had sleep apnea from the time she was very little, and by age 4 was also regularly having runny noses, strep infections, and inability to breathe through her nose. We used a lot of nutritional support, which improved things but never completely. When she entered middle school (much bigger), and hit puberty at the same time, she not only began having more infections, but they were far worse and she actually lost her sense of smell entirely. She also began having stress headaches pretty frequently--they would go away with rest, but she just never REALLY rested well because the apnea also got worse.
We finally had her tonsils and adenoids out at age 13. She just turned 18. From the time she came off the anesthesia/pain meds after that surgery 5 years ago, she has had a continuous, extremely painful (8-11, on a scale of 10) headache for FIVE YEARS!!!
After every doctor, naturopath, homeopath, and even a neurologist tried to change her biochemistry for over a year--believing it had something to do with hormones and was a series of migraines (remember, this is CONTINUOUS--it never goes away, she wakes up with it, goes to bed with it, not a single headache free day in 5 years now)--and after she had tried every migraine medication, a raw foods diet, an anti-seizure medication (because somebody once discovered it helped some migraines) and finally steroids, we noticed something else.
Her jaw couldn't open and close straight--it went sideways as she moved it. A chiropractor we then saw, who happened also to be a former Operating Room nurse, told us it is actually a standard procedure during the operation to dislocate the patient's jaw while under general anesthesia if the bone structure is small and tight--to enable the positioning of the clamp that holds the jaw open, and to allow the anesthesiologist, the surgeon, and the assistant all to have their hands in their at once.
A later dental panoramic x-ray and further orthodontic real-time computerized tests with my daughter wired with electrodes to every muscle in her face and neck confirmed that her jaw was misaligned badly. The Temporal Mandibular Joint-TMJ-contains a very important nerve that connects the lower jaw with the brain, and any misalignment can cause incredible pain.
Of course, by the time we figured all this out, my daughter--who had spent her ENTIRE adolescence in deep, searing pain that mostly kept her out of school, away from friends, and in her darkened bedroom--would have nothing to do with ANYONE (including mom) who said they could finally help. Too many people had put her through too many things. She was depressed, and angry. I found suicidal poetry she had written about never being out of pain forever. She began cutting on herself.
Later, she developed an anxiety disorder and began self-medicating with illegal things in order to stop the pain.
The good news is that, as she has matured out of the deepest part of adolescence, she is now doing much better, taking good care of herself with an excellent diet, and finding ways to use relaxation techniques to at least make it all bearable. We may be able to finally get her to see an orthodontist to do the retainers and braces (for 3 years) that she was told she needed. Why? Because she has a longer perspective, AND because sometimes now her jaw actually locks!
Oh, one thing...the surgery DID cure the apnea, strep infections, and loss of sense of smell. All that is all better. But what a cost!
So, while thousands of these surgeries are performed successfully every year, PLEASE really think through whether tonsils/adenoids are really the problem. Also, if you do decide to go through with it, TALK to the surgeon about whether dislocation of the jaw is a possibility, and what you might be able to do to help with even the natural rebound of the muscles tensing after being under general anesthesia.
If you do it, I strongly suggest an immediate assessment by a cranio-sacral therapist/chiropractor in the first week afterwards. This might have helped in my daughter's situation.