Updates in our understanding of local anaesthetic systemic toxicity: a narrative review

Despite advances in clinical practice, local anaesthetic systemic toxicity continues to occur with the therapeutic use of local anaesthesia. Patterns of presentation have evolved over recent years due in part to the increasing use of ultrasound which has been demonstrated to reduce risk. Onset of toxicity is increasingly delayed, a greater proportion of clinical reports are secondary to fascial plane blocks, and cases are increasing where non-anaesthetist providers are involved. The evolving clinical context presents a challenge for diagnosis and requires education of all physicians, nurses and allied health professionals about these changing patterns and risks. This review discusses: mechanisms; prevention; diagnosis; and treatment of local anaesthetic systemic toxicity. The local anaesthetic and dose used, site of injection and block conduct and technique are all important determinants of local anaesthetic systemic toxicity, as are various patient factors. Risk mitigation is discussed including the care of at-risk groups, such as: those at the extremes of age; patients with cardiac, hepatic and specific metabolic diseases; and those who are pregnant. Advances in the changing clinical landscape with novel applications and settings for the use of local anaesthesia are also described. Finally, we signpost future directions to potentially improve the management of local anaesthetic systemic toxicity. The utility of local anaesthetics remains unquestionable in clinical practice, and thus maximising the safe and appropriate use of these drugs should translate to improvements in patient care.     

An analysis of an admissions system: can performance in the first year of the dental course be predicted?

The admissions process must be scrupulously fair and select the most suitable students. Data on applicants to the Manchester Dental School for the 1996/97 academic year were analysed. The aims of this project were to: describe the applicants using information from the UCAS (university entrance) form; to relate information from the UCAS form to interview performance and A-level results; and to evaluate whether these factors can predict performance during the first year of the course.     

APOE epsilon4 allele and amyloid beta-protein deposition in long term survivors of head injury

Head injury and APOE epsilon4 are risk factors for Alzheimer's disease (AD). We previously found that deposits of amyloid beta-protein (Abeta) occur in fatal head injury, more frequently in patients with APOE epsilon4. We postulated that Abeta deposits triggered by injury could, in survivors, lead to AD-like pathology later in life. Here, we compared Abeta deposits in 21 long term survivors of head injury (up to 20 years) with age and APOE genotype matched controls. In both groups Abeta deposits were more common among patients with APOE epsilon4. However, Abeta deposits were not more common among survivors of head injury than controls. The findings support previous studies associating APOE epsilon4 with deposition of Abeta. However pathogenetic mechanisms other than Abeta deposition may explain the association of head injury with AD.     

Acid hydrolase activities in B cell chronic lymphocytic leukaemia lymphocytes: correlation of cytochemical reactions with immunological phenotype

The cytochemical reactions of 5 acid hydrolases, alpha-naphthyl acetate esterase (ANAE), acid phosphatase (AP), beta-glucuronidase, beta-glucosaminidase and dipeptidylaminopeptidase IV (DAP IV) were investigated in lymphocytes from 30 patients with B cell chronic lymphocytic leukaemia (B-CLL). Based on ANAE and AP reactivities, 4 cytochemically distinctive subgroups were identified: Group 1: AP and ANAE less than 50% positive lymphocytes (5 cases); Group 2: AP greater than 50%, ANAE less than 50% positive lymphocytes (11 cases); Group 3: AP less than 50%, ANAE greater than 50% positive lymphocytes (7 cases); Group 4: AP and ANAE greater than 50% positive lymphocytes (7 cases). beta-Glucuronidase displayed similar patterns of reactivity to AP. beta-Glucosaminidase activity was observed in the majority of lymphocytes in most patients, whereas DAP IV activity was present in less than 20% of lymphoid cells. The study failed to establish any relationship between cytochemical grouping and patients' clinical status, peripheral lymphocyte counts, E or mouse rosette values, light or heavy chain cellular immunoglobulin (Ig) class. Attempts to correlate acid hydrolase and Ig heavy chain isotype expression, putative markers of B cell maturation, were unsuccessful and indicate that within the narrow spectrum of B cell differentiation seen in B-CLL these characteristics are unrelated.     

A place for ipratropium bromide in the treatment of severe acute asthma

Twenty-four consecutive patients admitted to hospital with severe acute asthma were studied. Eleven were given 10 mg salbutamol by nebulizer followed 2 hours later by 500 micrograms of nebulized ipratropium bromide. These patients had a greater response in PEFR than 13 patients given two doses of 10 mg salbutamol 2 hours apart.