Prior to the preparation of a tooth for a porcelain-fused-to-metal crown, a dentist anaesthetized a patient with a history of bronchial asthma with 2% solution of novocaine. A few minutes later, the patient complained of shortness of breath (more difficult expiration), there appeared acrocyanosis, swollen neck veins, Ps-100 bpm, rhythmic, AP- 180/110 mm Hg. Percussion revealed box sound over lungs. What is the most likely diagnosis?