Median effective volume of 0.3％ ropivacaine in old patients with femoral intertrochanteric fracture undergoing ultrasound-guided fascia iliaca compartment block / 临床麻醉学杂志

ABSTRACT

Objective To identify the median effective volume (EV50) of 0.3 ％ ropivacaine in the old patients with femoral intertrochanteric fracture undergoing ultrasound-guided fascia iliaca compartment block (FICB).Methods Thirty-nine patients,18 males and 21 females,aged 65-98 years old,ASA physical status Ⅱ or Ⅲ,scheduled for femoral intertrochanteric fracture surgery were sequentially received ultrasound-guided FICB.Patients were sequentially given a pre-set volume of 0.3％ ropivacaine according to our pilot study.A sign of "+" was marked if the patient was positive to FICB and totally pain-free 30 min after block,and the next patient would be assigned to a lower volume of ropivacaine.Otherwise,a sign of was marked if the patient was negative to FICB that was partially or not pain-reliefed 30 min after block,and the next patient would be assigned to a larger volume of ropivacaine.The trial was terminated when 7 inflection points appeared.The EV50 of 0.3％ ropivacaine with 95％ confidence interval (CI) was calculated according to sequential method.Results Twenty (51.3％) in a total of 39 patients received a successful ultrasound-guided FICB.The EV50 and 95 ％ CI of 0.3 ％ ropivacaine using ultrasound-guided FICB in old patients with femoral intertrochanteric fracture was 25.37 ml (95％CI 22.06-29.19 ml).Conclusion The EV50 of 0.3％ ropivacaine using ultrasound-guided FICB in the old patients with femoral intertrochanteric fracture is 25.37 ml.