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 2 was a previously healthy, 52-year-old male with a spontaneous complete rupture of the left supraspinatus tendon. The patient received an arthroscopic rotator cuff repair, and a single-injection ISB combined with TIVA was selected as the anesthetic strategy. Preprocedural BP was 130/60 mm Hg; HR 66 bpm; SpO2 values 99–100%. After ultrasound- and PNS-guided placement of a left ISB, the brachial nerve block was performed by injecting 1% lidocaine (10 mL) followed by 0.375% ropivacaine (10 mL). There was a negative aspiration test for blood and cerebrospinal fluid prior to injection. Physical examination revealed an effective interscalene block. Adverse cardiac or neurologic symptoms were not recorded. After induction of anesthesia, and intubation, TIVA was maintained with propofol and sufentanil. 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 SBP levels of 100–120 mmHg were interrupted by SBP levels of ≥90 and <100 mmHg for a maximum of 35 min due to the application of controlled hypotension. Administration of antihypertensive and/or vasoconstrictor drugs was not recorded. SpO2 (98–100%) and ETCO2 values (34–37%) were normal throughout the case. The duration of surgery was 56 min. After termination of TIVA, and extubation in the OR, the patient presented with impaired consciousness and aphasia, a left-sided gaze preference, dysphagia, mild-to-moderate right-sided central facial palsy, right-sided hemiplegia, and right-sided positive pyramidal tract signs. Brain imaging four hours post-surgery did not detect any cerebral lesions.