Comparison of Effectiveness of Ropivacaine Infusion Regimens for Continuous Femoral Nerve Block for Recovery After Total Knee Arthroplasty: A Randomized Double-Blind Trial

Figures & data

Figure 1 CONSORT flow diagram.

Table 1 Demographic and Intraoperative Characteristics

Characteristics	0.1% Group (n=20)	0.15% Group (n=20)	0.2% Group (n=20)	P-value
Age, y	72 (5.5)	69 (8)	74 (15.1)	0.579
Sex (female/male)	13/7	16/4	14/6	0.563
BMI, kg/m^2	24.7 (2.6)	25.3 (2.63)	24.2 (3.4)	0.480
ASA classification (I/II)	7/13	5/15	6/14	0.788
Surgical duration, minutes	110.8 (18.3)	106.4 (17.1)	113.5 (22.2)	0.051

Note: Measured data with normal distribution were expressed as mean (standard deviation).

Abbreviations: BMI, body mass index; ASA, American Society of Anesthesiologists.

Figure 2 The time to readiness for discharge and the time to first walk. (A) Kaplan–Meier curves demonstrated earlier readiness for discharge among patients in the 0.15% group and 0.2% group than in the 0.1% group (P=0.005 and P=0.001); (B) Kaplan–Meier curves demonstrated earlier walking (B) among patients in the 0.15% group and 0.2% group than in the 0.1% group (P=0.002 and P=0.004).

Abbreviations: 0.1% group, patients received infusion of 10 mL of 0.1% ropivacaine per hour, with a total dosage of 10 mg ropivacaine per hour; 0.15% group, patients received infusion of 6.7 mL of 0.15% ropivacaine per hour, with a total dosage of 10 mg ropivacaine per hour; 0.2% group, patients received infusion of 5 mL of 0.2% ropivacaine per hour, with a total dosage of 10 mg ropivacaine per hour.

Figure 3 Comparison of MMT scores between the 0.1% group, 0.15% group, and 0.2% group. Values are median (interquartile range), n=20.

Abbreviations: MMT, manual muscle testing; 0.1% group, patients received infusion of 10 mL of 0.1% ropivacaine per hour, with a total dosage of 10 mg ropivacaine per hour; 0.15% group, patients received infusion of 6.7 mL of 0.15% ropivacaine per hour, with a total dosage of 10 mg ropivacaine per hour; 0.2% group, patients received infusion of 5 mL. Two percent ropivacaine per hour, with a total dosage of 10 mg ropivacaine per hour.

Figure 4 (A) NRS scores (ranging from 0 to 10) for pain at rest; (B) NRS score (ranging from 0 to 10) for pain on movement. Values are mean (standard deviation), n=20.

Abbreviations: NRS, numerical rating scale; 0.1% group, patients received infusion of 10 mL of 0.1% ropivacaine per hour, with a total dosage of 10 mg ropivacaine per hour; 0.15% group, patients received infusion of 6.7 mL of 0.15% ropivacaine per hour, with a total dosage of 10 mg ropivacaine per hour; 0.2% group, patients received infusion of 5 mL of 0.2% ropivacaine per hour, with a total dosage of 10 mg ropivacaine per hour.

Table 2 Morphine Consumption and Cases of Rescue Analgesia

	0.1% Group (n=20)	0.15% Group (n=20)	0.2% Group (n=20)	P-value
Morphine consumption, mg	8.7 (1.2)	8.0 (1.3)	5.9 (1.0)	0.309
Case of rescue analgesia (%)	7 (35%)	2 (10%)	3 (15%)	0.116

Note: Morphine consumption was expressed as mean (standard deviation).