Bed bugs are a challenge in the fumigation business. The skin of the insect is not permeable so, even if you manage to have your sprayed insecticide touch the bed bug. still it may not kill it. The only way is to make the poison go into the lungs of the bed bug.
In order to have the bed bug inhale the pesticide, use Poison Gas Tablets. Seal the whole premises, then an experienced and professional fumigator carefully puts the tablets in trays on the floor at different locations (dosage according to instructions) and leave the premises before inhaling. He then closes the door and use masking tape to even seal the door. The tablets release gas which kills any living thing present inside the premises at that time. The premises is left for around 24 hours. Opening the door also requires same precautions. This is a dangerous procedure and should always be applied by professional person.