Puppy pulled out his drainage tube, what should I do?

Call your vet....there is always someone on call after hours who will get back to you. It will probably be a tech who will call the vet if necessary. They will advise you what to do, if anything. I would not wait. Why let the little dog be irritable and uncomfortable when it may be something can be resolved easily. Even if you would need another prescription, there usually is an emergency animal hospital that your vet can call in for the meds. Good luck.....I hope you dog will have a speedy recovery.