Dose calculation of local anesthetic agent is the must know thing for a dentist. Approximately 1 million cartridges of local anesthetic are used each day in the United States.
Local anesthetic systemic toxicity (LAST) is dose-related and although rare, occurs more frequently in small children than adults. LAST occurs more frequently when the patient is administered concomitant central nervous system (CNS) depressants, such as opioid/sedative medications.
Local anesthetics are essential for intraoperative dental analgesia; they work by blocking sodium channels in neurons so that pain signals from the periphery cannot be transmitted to the CNS.
LAST is mediated by the same mechanism when the maximum recommended dose (MRD) is exceeded.
This dose-related toxicity is especially important as the sodium channels in the cardiovascular system are blocked along with those in the CNS.
Without proper knowledge of it, no adequate anesthesia can be achieved and their may be risk of toxicity of specific agents too if not calculated and taken into consideration.