Use of hyaluronidase 75 TRU/ml concomitantly with mepivacaine associated epinephrine and inferior alveolar nerve block: hemodynamic and electrocardiographic study

Among the adjuvants to local anesthetics (LA), the enzyme hyaluronidase has its consecrated in ophthalmic anesthesia as a diffuser (spread) of the LA. It is used to improve the clinical efficacy and prolong anesthesia as an alternative to long lasting local anesthetics in patients with systemic involvement. This double-blind, controlled trial evaluated the cardiovascular effects induced by 3.6 ml of local anesthetic (LA) 2% mepivacaine hydrochloride with epinephrine 1:100,000 concomitantly with hyaluronidase 75 TRU/ml or placebo (vehicle) in blocking inferior alveolar nerve for performing third molar surgery bilateral and symmetrical in 20 patients. Surgery was performed only one by appointment, at the same time and operator. The cardiovascular parameters systolic blood pressure (SBP), diastolic blood pressure (DBP), mean blood pressure (MBP) and heart rate (HR) were monitored using the oscillometric method and photoplethysmography in 10 clinical stages. Records electrocardiographic (ECG) of 12 leads were obtained in four steps: (T1) baseline, (T2) local anesthetic, (T3), 5 mim AL, (T4) after surgery. ECG were evaluated in the following variables: heart rate, duration of PR segment, duration of the complex QRS, duration of the corrected QT interval. Hyaluronidase injected concomitantly with local anesthetic did not induce changes in the SBP, DBP, MBP, and HR (p> 0.01, n = 20) compared to placebo, except in the interaction between steps and drugs (p<0.01) for SBP and HR. There were no ECG changes (n = 18) considered of clinical importance as ST segment depression, ST segment elevation, extrasystoles wide QRS complex and extrasystoles of narrow QRS complex. The use of local anesthetic injected concomitantly with hyaluronidase 75 TRU/ml was safe at this dose and route of administration.