Intrathecal chloroprocaine or hyperbaric prilocaine for ambulatory knee surgery? A prospective randomized study

Abstract

Purpose: The aim of this study was to compare intrathecal 1% chloroprocaine with 2% hyperbaric prilocaine in the setting of ambulatory knee arthroscopy. We hypothesized that complete resolution of the sensory block was faster with chloroprocaine.

Methods: Eighty patients scheduled for knee arthroscopy were included in this prospective randomized double-blind study. Spinal anesthesia was performed with either chloroprocaine (50 mg) or hyperbaric prilocaine (50 mg). Characteristics of sensory and motor blocks and side effects were recorded.

Results: Mean time to full sensory block recovery was shorter with chloroprocaine (169 (56.1) min vs 248 (59.4)). The characteristics of the sensory blocks were similar at the T12 dermatome level between the two groups. Differences appeared at T10: the percentage of patients with a sensory block was higher, onset quicker and duration longer with hyperbaric prilocaine. The number of patients with a sensory block at T4 dermatome level in both groups was minimal. Times to full motor recovery were identical in both groups (85 (70-99) vs 86 (76-111) min). Time to spontaneous voiding was shorter with chloroprocaine (203 (57.6) min vs 287.3 (47.2) min). Incidence of side effects was low in both groups.

Conclusions: When considering the characteristics of the sensory block, the use of chloroprocaine may allow an earlier discharge of patients. Cephalic extension was to a higher dermatomal level and the sensory block at T10 level was of prolonged duration with hyperbaric prilocaine, suggesting that the choice between the two drugs should also be performed based on the level of the sensory block requested by the surgery. This study is registered in the US National Clinical Trials Registry, registration number: NCT030389 , the first of February 2017, Retrospectively registered.

Keywords: Chloroprocaine; Hyperbaric prilocaine; Prospective study; Sensory block; Spinal anesthesia.

Fig. 1

Flowchart patients scheduled for knee arthroscopy with Chloroprocaine (CG) or Hyperbaric prilocaine (HPG)

Fig. 2

a Percentage of patients with a complete loss of cold sensation at the T12 dermatome during the first 30 min after local anesthetics injection. b Time to obtain a T12 dermatome level extension of sensory block evaluated with cold test. c Duration of sensory block at T12 dermatome level evaluated with cold test. d Percentage of patients with negative pin-prick test at T12 dermatome level during the first 30 min after local anesthetics injection. e Time to obtain a T12 dermatome level extension of sensory block evaluated with pin-prick test. f Duration of sensory block at T12 dermatome level evaluated with pin-prick test. Statistically significant differences are marked with *(P < 0.05)

Fig. 3

a Percentage of patients with a complete loss of cold sensation at T10 dermatome during the first 30 min after local anesthetics injection. b Time to obtain a T10 dermatome level extension of sensory block evaluated with cold test. c Duration of sensory block at T10 dermatome level evaluated with cold test. d Percentage of patients with negative pin-prick test at T10 dermatome during the first 30 min after local anesthetics injection. e Time to ontain a T10 dermatome level extension of sensory block evaluated with pin-prick test. f Duration of sensory block at T10 dermatome level evaluated with pin-prick test. Statistically significant differences are marked with *(P < 0.05)

Fig. 4

a Percentage of patients with a complete loss of cold sensation at T4 dermatome level during the first 30 min after local anesthetics injection. b Percentage of patients with negative pin-prick test at the T4 dermatome level during the first 30 min after local anesthetics injection. Statistically significant differences are marked with *(P < 0.05)

Fig. 5

a Percentage of patients with a complete motor block (Bromage 3) during the first 30 min after local anesthetics injection. b Time to obtain complete recovery of motor block (Bromage 0). Statistically significant differences are marked with *(P < 0.05)