An 8-year-old healthy male patient (30 kg weight and 130 cm height) with no history of epilepsy visited the dentist for tooth extraction. The patient had no known drug allergies. During his visit for extraction of deciduous second molar, the dentist injected 1.8 ml of 2% lignocaine (36 mg) with adrenaline (1:200,000) after prior aspiration at upper left maxillary vestibule with respect to deciduous second molar followed by 0.5 ml at left greater palantine nerve block. The total 46 mg lignocaine lasting over 2 min was administered. Immediately following the nerve block, the child presented with tonic-clonic convulsions. Patient was placed in supine position with elevated legs, and care was taken so as to protect from injuries. Injection diazepam was given. The vital signs and all laboratory investigations were normal. Neurological examination was unremarkable. MRI scan of the head and electroencephalogram were normal. There was no recurrence of seizures and the child was discharged after 1 day. Using Naranjo probability scale the relationship between the drug and the event was categorized as probable.
Patient 1 was a 52-year-old male with a medical history of multiple sclerosis, who underwent arthroscopic rotator cuff repair due to a spontaneous complete rupture of the left supraspinatus tendon. The positioning of the patient applied during surgery was the beach chair position. Preoperative blood pressure (BP) was 135/80 mm Hg; heart rate (HR) 66 beats per minute (bpm); oxygen saturation (SpO2) values between 98% and 100%. For premedication, the patient received orally administered midazolam. Single-injection ISB was performed prior to induction of anesthesia and intubation. Total intravenous anesthesia (TIVA) was maintained with propofol and sufentanil. For left ISB, the patient initially received single-dose injections of 1% lidocaine (20 mL) and 0.75% ropivacaine (20 mL) followed by a second single-dose injection of 0.75% ropivacaine (10 mL) three hours after initial local anesthetic injections and 15 min prior to termination of TIVA, and extubation. Safety checks prior to injection did not show any aspiration of blood or cerebrospinal fluid. Adverse cardiac or neurologic symptoms were not recorded. Advancement and placement of the catheter was performed in PNS technique using a stimulating catheter. An effective ISB was confirmed by physical examination prior to surgery. BP was measured every 5 min with a noninvasive cuff. The patient underwent an uneventful operative rotator cuff repair under the ISB and intravenous anesthesia. Intraoperatively, recorded systolic blood pressure (SBP) levels of 100–110 mmHg were interrupted by SBP levels of ≥90 and <100 mmHg for a maximum of 90 min due to the application of controlled hypotension. Administration of antihypertensive and/or vasoconstrictor drugs was not recorded. SpO2 (98% to 100%), and end-tidal CO2 (ETCO2) values (30% to 34%) were normal throughout the case. The duration of surgery was 170 min. After termination of TIVA, and extubation in the operating room (OR), the patient remained in a severely impaired conscious state. In the postanesthesia care unit the patient showed a sustained severe impairment of consciousness, and neurological examination by a neurologist additionally revealed aphasia, multi-modal neglect to the right, left-sided gaze preference, dysphagia, severe right-sided central facial palsy, severe right-sided hemiparesis graded as 2/5 according to the Medical Research Council (MRC) scale for muscle strength, right-sided positive pyramidal tract signs, and right-sided hemihypesthesia. These symptoms were further accompanied by complex behavioural manifestations (anxiety, vocalization, aggression) and facial motor movements suggesting complex focal seizures. Due to vomiting with pulmonary aspiration, the patient underwent an emergency intubation. Brain imaging four hours post-surgery did not detect any cerebral lesions.