Spinal anaesthesia with Chloroprocaine HCl 1% for elective lower limb procedures of short duration: a prospective, randomised, observer-blind study in adult patients

Abstract

Background: This prospective, randomised, observer-blinded study has been conducted in patients undergoing procedures of the lower extremities to evaluate the time to complete block resolution of 2-chloroprocaine 1% at three intrathecal doses (30, 40 and 50 mg).

Methods: After informed consent, we enrolled 45 male and female patients, aged 18-65 years, ASA score I-II, BMI 18-32 kg/m2, undergoing elective lower limb procedures lasting ≤40 min and with a requested dermatomeric level of sensory block ≥ T12. The patients were randomised in a 1:1:1 ratio to receive Chloroprocaine HCl 1% at one of the three different intrathecal doses (Group 30 = 30 mg, Group 40 = 40 mg or Group 50 = 50 mg). The progression and regression of both sensory and motor blocks were evaluated blindly. Urine and venous blood samples were collected for pharmacokinetic analysis.

Results: Times to regression of spinal blocks were 1.76 ± 0.35 h, 2.13 ± 0.46 h and 2.23 ± 0.38 h, in Group 30, 40 and 50 respectively: the 30 mg dose showed a significantly faster resolution of spinal block than the 40 mg (p = 0.034) and the 50 mg (p = 0.006). Time to readiness for surgery was significantly reduced with the dose of 50 mg when compared to dose of 30 mg (p = 0.0259).

Conclusions: The doses of 50 mg and 40 mg yielded a longer resolution of spinal block than the dose of 30 mg. Nevertheless, the dose of 30 mg resulted in a higher secondary failure rate.

Trial registration: Registration of clinical trial: clinicaltrials.gov ( NCT02481505 ).

Keywords: Ambulatory, subspecialties; Anaesthetics, local; Chloroprocaine; Neuraxial blocks: spinal, regional anaesthesia; Transient neurologic symptoms, complications.

Conflict of interest statement

Daniela Ghisi has participated as a medical consultant to a scientific advice with Sintetica S.A. The other authors have no competing interest to declare.

Figures

Fig. 1

The investigator included 46 subjects in the study. One subject (S030/029) discontinued the study before receiving the assigned anaesthesia due to non-compliance. Among the remaining 45 patients, 15 enrolled subjects received chloroprocaine 30 mg, other 15 received chloroprocaine 40 mg, and other 15 received chloroprocaine 50 mg. Forty-five subjects completed the study as planned

Fig. 2

CABA increased in plasma after the spinal injection of the parent compound and reached a peak 30 min post-dose. Plasma CABA concentrations increased with the increase in chloroprocaine dose