Medical care in Laos is extremely limited. Even if you find a good doctor (and considering how badly most of them are paid, that is far from guaranteed) they are highly unlikely to have all the necessary equipment to give you good treatment.
Some people have asked me whether it’s a good idea to travel to Laos for low-cost elective surgery. My answer is, I’ve never heard of anyone doing that, and I wouldn’t take the risk. Thailand - yes. Laos - no. If you meet someone who has actually done it, I would be very interested to hear about their experience.
If you get sick or injured in northern or southern Laos, and you are anywhere near the Thai border, my strong advice is to get across to Thailand as fast as humanly possible. There, you will usually be in good hands. If you are near the Vietnamese border, you might try in Vietnam. Laos is a poor country with less than 10% of the population of either Thailand or Vietnam, so it simply doesn’t have the same resources as its larger neighbours.
In Vientiane, I have heard good things about the Alliance Medical Centre (http://www.aimclao.com/contact-us). I have never used them. If you do so, let me know how it goes.