Chloroprocaine vs. articaine as spinal anaesthetics for day-case knee arthroscopy

Chloroprocaine and articaine have recently gained interest as short-acting spinal anaesthetics. They have not, however, previously been compared in an ambulatory surgery setting.

In this double-blind, randomised, controlled trial, adult patients (≤65 years, ASA I-II, body mass index<36 kg/m2) underwent day-case knee arthroscopy under spinal anaesthesia with either 40 mg of plain chloroprocaine (20 mg/ml) (group C40; n=39) or 60 mg of plain articaine (40 mg/ml) (group A60; n=39). Study parameters included the onset, degree, and regression of both sensory and motor block. Standardised telephone interviews on the first and seventh post-operative day were aimed at detecting any untoward sequelae, e.g., transient neurologic symptoms (TNSs).

The groups were comparable regarding demographic data, onset and maximal spread of spinal anaesthesia, and duration of surgery. All arthroscopies were performed successfully under spinal anaesthesia, except for one patient (C40, unforeseen delay in the start of surgery). The duration of sensory block≥dermatome L1 was significantly shorter in C40 vs. A60. Correspondingly, complete recovery was significantly faster (P<0.0001, Mann-Whitney U-test) in C40 vs. A60 for both motor [75 (60/90) vs. 135 (105/150) min] and sensory [105 (105/135) vs. 165 (135/180) min] block, respectively [data are median (25th/75th percentiles)]. No TNSs were noted.

Both anaesthetics used provided a rapid onset of spinal anaesthesia of about 1 h and were satisfactory for day-case knee arthroscopy. Recovery, however, was significantly faster in group C40. The data add to earlier results that TNSs seem to be uncommon after spinal chloroprocaine and articaine.