Comparative Evaluation of Local Anaesthesia with and without Adrenaline on Haemodynamic and Metabolic Responses during Tooth Extraction: A Prospective Study

Abstract

Introduction: Local Anaesthetic (LA) solutions often incorporate vasoconstrictors to delay the systemic absorption of the drug. This prolongs the duration of anaesthesia, reduces toxicity by slowing systemic uptake, lowers the total required dose of LA and enhances anaesthetic efficacy by localising the drug at the injection site. Despite extensive published literature, the systemic metabolic effects of these agents in diabetic dental patients remain underexplored. Aim: To evaluate the effect of local anaesthesia with and without adrenaline on blood glucose levels and haemodynamic parameters in patients undergoing routine tooth extractions. Materials and Methods: This prospective study was conducted at the Department of Oral and Maxillofacial Surgery, Bharati Vidyapeeth Dental College, and Hospital, Sangli, Maharashtra, India, from January 2017 to December 2019. The study included 120 patients aged 17 to 65 years requiring multiple tooth extractions, comprising both medically stable non-diabetic individuals and patients with controlled Type 2 Diabetes Mellitus (T2DM) as the primary inclusion criteria. Each participant received two anaesthetic regimens in separate appointments in randomised order. Haemodynamic parameters (systolic and diastolic blood pressure, heart rate) and random blood glucose levels were recorded before injection (R0), immediately after (R1), and at 10 (R2) and 20 minutes (R3) post-injection. Data were analysed using repeated-measures Analysis of Variance (ANOVA) with Bonferroni post-hoc tests for intragroup comparisons, Independent t-tests for intergroup change scores, and Chi-square tests for categorical variables (p≤0.05). Results: Lignocaine with adrenaline produced significant transient increases in systolic blood pressure, heart rate, and blood glucose levels in diabetic subjects compared with plain lignocaine (p<0.001). Non diabetic patients exhibited smaller, but statistically significant increases in haemodynamic parameters with adrenaline (p<0.05). Blood glucose changes were also statistically significant with adrenaline in non diabetic patients as well (+11.8 mg/dL, p<0.001), although less pronounced than in diabetic subjects. Diastolic blood pressure showed statistically significant but clinically modest increases with adrenaline in both groups (p<0.001), whereas plain lignocaine produced minimal diastolic pressure. Conclusion: LA solutions can elicit systemic metabolic responses, and caution is warranted when using lignocaine containing adrenaline in patients with T2DM patients. Clinicians should consider plain LA alternatives for diabetic patients when prolonged anaesthesia or enhanced haemostasis is not essential. Patient specific risk assessment is recommended preoperatively, particularly for those with suboptimal glycaemic control despite HbA1c ≤7%. Future studies should evaluate longer term impact on glycaemic control and incorporate non invasive cardiac output monitoring.