Background and Goal of Study: Both articaine (A) and 2-chloroprocaine (C) are presently being considered as short-acting spinal anaesthetics (1, 2). These two drugs, however, have not been previously compared in an ambulatory surgery setting. Based on earlier studies and experiences, we hypothesised that spinal A 60 mg and C 40 mg do not differ in block onset, maximal spread, and recovery.
Materials and Methods: This randomised, double-blind study had Ethics Committee and National Agency for Medicines approval. Adult patients (±65 years, ASA I-II, BMI<36) underwent day-case knee arthroscopy under spinal anaesthesia accomplished by either 60 mg plain A (40 mg/ml) (group A60; n=39) or 40 mg plain C (20 mg/ml) (group C40; n=40). Study parameters included onset, degree, and regression of both sensory (pin-prick) and motor (modified Bromage scale) block. Standardised interviews by telephone on day 1 and 7 aimed at detecting possible transient neurologic symptoms (TNS).
Results and Discussion: The groups were comparable regarding demographic data, onset (e.g., time needed to reach dermatome L1, Table) and maximal spread of spinal anaesthesia, and duration of surgery. All arthroscopies could be performed successfully under spinal anaesthesia except in one patient (C40, unforeseen delay in the start of surgery). Occasionally, small supplementary doses of fentanyl i.v. (50–150 μg) (A60 ×1, C40 ×3) and propofol i.v. (50 mg, C40 ×1) were given during surgery. The duration of sensory block ≥ dermatome L1 was significantly longer in A60 vs. C40 and, similarly, complete recovery from both motor and sensory block was significantly slower in A60 vs. C40 (Table). Patients from A60 were discharged home later as compared to Group C40 (p<<0.0003, t-test). No TNS were noticed.
Conclusion(s): Both A60 and C40 provided rapid onset spinal anaesthesia lasting for about one hour and allowing day-case knee arthroscopy. Recovery, however, was clearly faster with C40. The data support earlier findings that TNS are no, or at the most a very rare problem with articaine and 2-chloroprocaine.
1 Yoos and Kopacz, Anesth Analg 2005.
2 Kallio et al., Br J Anaesth 2006.