During the frenuloplasty of the superior labial frenulum, a 9-year-old girl, who received infiltration anesthesia with 1.0 mL of Sol. Ultracain DS, complained of dizziness, nausea, weakness, and ringing in her ears. Objectively, her skin is pale and covered in cold sweat, her respiration is rapid, the pulse is of poor volume, the blood pressure is 90/60 mm Hg. What is the most likely diagnosis in this case?