Initial symptoms of systemic toxicity include ringing in the ears (tinnitus), a metallic taste in the mouth, tingling or numbness of the mouth, dizziness and/or disorientation. At higher concentrations, a relatively selective depression of inhibitory neurons results in cerebral excitation, which may lead to more advanced symptoms include motor twitching in the periphery followed by grand mal seizures. It is reported that seizures are more likely to occur when bupivacaine is used, particularly in combination with chloroprocaine.A profound depression of brain functions may occur at even higher concentrations which may lead to coma, respiratory arrest, and death. Such tissue concentrations may be due to very high plasma levels after intravenous injection of a large dose. Another possibility is direct exposure of the central nervous system through the cerebrospinal fluid, i.e., overdose in spinal anesthesia or accidental injection into the subarachnoid space in epidural anesthesia. Cardiovascular system
Cardiac toxicity can result from improper injection of agent into a vessel. Even with proper administration, it is inevitable for some diffusion of agent into the body from the site of application due to unforeseeable anatomical idiosyncrasies of the patient. This may affect the nervous system or cause the agent to enter into general circulation. However, infections are very seldom transmitted. Cardiac toxicity associated with overdose of intravascular injection of local anesthetic is characterized by hypotension, atrioventricular conduction delay, idioventricular rhythms, and eventual cardiovascular collapse. Although all local anesthetics potentially shorten the myocardial refractory period, bupivacaine blocks the cardiac sodium channels, thereby making it most likely to precipitate malignant arrhythmias.
Cause
The lateral femoral cutaneous nerve most often becomes injured by entrapment or compression where it passes between the upper front hip bone (ilium) and the inguinal ligament near the attachment at the anterior superior iliac spine (the upper point of the hip bone). Less commonly, the nerve may be entrapped by other anatomical or abnormal structures, or damaged by diabetic or other neuropathy or trauma such as from seat belt injury in an accident.The nerve may become painful over a period of time as weight gain makes underwear, belting or the waistband of pants gradually exert higher levels of pressure. Pain may be acute and radiate into the rib cage, and into the groin, thigh, and knee. Alternately, weight loss or aging may remove protective fat layers under the skin, so the nerve can compress against underwear, outer clothing, and—most commonly— by belting. Long periods of standing or leg exercise that increases tension on the inguinal ligament may also cause pressure.The lateral cutaneous nerve of the thigh can occasionally be damaged during laparoscopic hernia repair, or scarring from the operation can lead to meralgia paraesthetica. Diagnosis
Diagnosis is largely based on patient  description and relevant details about recent surgeries, hip injuries, or repetitive activities that could irritate the nerve.