I'm no medical doctor, but this is my understanding from my own experience and that of many other fellow SCLS patients:
1) Most of us don't have a 2nd episode until many weeks or months or even years have passed after the 1st episode, so first of all, don't worry yourselves sick about having to go through what you just went through all over again.
Right now, your husband's physical rehabilitation, and your own mental and emotional rehabilitation, should take 1st priority. In many ways, care givers such as yourself suffer as much or more than patients, so feel free to get medical or psychological help for yourself and your children, if you have any, and lean on your family and friends for emotional support.
2) It's not a bad idea to start on one or both of these medications now, while he's still in a hospital setting, under watch. Theophylline tends to be given first, with or without Terbutaline, starting at a low dose to see how the patient reacts. Nothing is written in stone, however. Both medications have side effects, as you will see by searching the Internet, so fasten your seatbelt: Look for an increased heart rate, nervousness, irritability and insomnia as the dosage rises -- and Terbutaline is also prone to induce shaking (in one-third of patients).
3) As the dosage will probably keep getting hiked after you both return home, I advise you to insist that your MD prescribe a tranquilizer for your husband, or at least something to help him fall asleep. In case they don't tell you this, it's best to take these medications in the morning and afternoon -- preferably never in the evening, just like you would never want to take 20 cups of coffee after 8PM.
4) These medications don't always work in preventing the severity or frequency of future episodes, so early detection and better management of any additional episodes that may come along will need to become a priority going forward.
Good luck! You deserve to have some after what you've been through.