Efficacy of ultrasound-guided adductor canal block for postoperative analgesia in pediatric patients undergoing knee operation / 中华麻醉学杂志

Objective To investigate the efficacy of adductor canal block (ACB) under the guidance of ultrasound for postoperative analgesia in the pediatric patients undergoing knee operation.Methods Sixty pediatric patients,aged 3-12 yr,of American Society of Anesthesiologists physical status Ⅰ or Ⅱ,weighing 12-35 kg,scheduled for elective unilateral knee operation,were selected and randomly divided into 2 equal groups using a random number table:ultrasound-guided ACB group (group ACB) and ultrasound-guided femoral nerve block (FNB) group (group FNB).After induction of general anesthesia,ACB or FNB was performed under the guidance of ultrasound,and 0.3％ ropivacaine 1 ml/kg was injected.Anesthesia was maintained with intravenous infusion of remifentanil combined with propofol,and bispectral index value was maintained at 40-60.Immediately after injection of local anesthetics (T0),and at 4,8,12 and 24 h after injection (T1-4),analgesic efficacy was assessed using the FLACC pain scale,and quadriceps strength was assessed by manual muscle testing.Satisfactory analgesia was defined as FLACC score ≤ 3,and obvious quadriceps weakness was defined as manual muscle testing grade 0-2.The complications associated with nerve block (such as local anesthetic toxicity,bleeding at the puncture site,hematoma),and occurrence of postoperative nausea and vomiting and delayed emergence were recorded.Results There was no significant difference between two groups in the rate of satisfactory analgesia at T1-T4 (P＞ 0.05).Compared with group FNB,the incidence of obvious quadriceps weakness was significantly lower at T1-T3 (P＜0.05),and no significant change was found at T4 in group ACB (P＞0.05).There was no significant difference in the incidence of nausea or retching between two groups (P＞0.05).Complications associated with nerve block,vomiting and delayed emergence were not observed in the two groups.Conclusion Ultrasound-guided ACB can be safely and effectively used for postoperative analgesia in the pediatric patients undergoing knee operation,and it has less influence on the quadriceps strength than FNB.

Reliability of ultrasound for rapid identification of esophageal intubation in patients with difficult airway / 中华麻醉学杂志

Objective To evaluate the reliability of ultrasound for rapid identification of esophageal intubation in the patients with difficult airway.Methods Twenty-one patients requiring orotracheal intubation, aged 20-75 yr, with body mass index of 25-32 kg/m2, of ASA physical status Ⅰ or Ⅱ , Cormack-Lehane grade Ⅲ or Ⅳ under direct laryngoscope, undergoing elective general anesthesia, were selected.The carotid artery, trachea and esophagus were identified by ultrasonic scanning at suprasternal notch before induction of anesthesia.After induction of anesthesia, tracheal intubation was performed.During intubation, ultrasound was performed to detect esophageal intubation.After intubation, mechanical ventilation was performed.Auscultation of bilateral breath sounds was carried out to evaluate the tube position.The position of the tube was subsequendy determined through partial pressure of end-tidal CO2 monitoring.Results The sensitivity and specificity of ultrasound in identifying esophageal intubation were both 100％ in the patients with difficult airway.Conclusion Ultrasound can rapidly and effectively identify esophageal intubation in the patients with difficult airway.

Value of ultrasound-measured quantification of anterior neck soft tissue in predicting difficult laryngoscopy in obese patients / 中华麻醉学杂志

Objective To evaluate the value of ultrasound-measured quantification of anterior neck soft tissue in predicting the difficult laryngoscopy in the obese patients.Methods Ninety-six patients,with body mass index ≥ 28 kg/m2,aged 22-60 yr,of ASA physical status Ⅰ or Ⅱ,scheduled for elective surgery under general anesthesia with endotracheal intubation,were selected.Assessment methods of modified Mallampati grade (method M) and anterior neck soft tissue quantification measured by ultrasound (method U) were performed before anesthesia.The level of vocal cords was selected using ultrasound scanning for anterior neck.The positive result was greater than 20 mm in method U,and was grade Ⅲ or Ⅳ in method M.Direct laryngoscope was placed after induction of anesthesia.Difficult laryngoscopy was defined as Cormack-Lehane grade Ⅲ or Ⅳ,or in whom laryngoscope could not be placed.The sensitivity,specificity and accuracy of the two assessment methods for predicting the difficult laryngoscopy were calculated.Results Twenty-two patients were found to have difficult laryngoscopy,and the anterior neck soft tissue quantification was (23.0±3.0) mm,which was significantly thicker than that in the patients of non-difficult laryngoscopy ((1.9±2.2) mm).The sensitivity,specificity and accuracy of method U were 91％,92％ and 92％,respectively,and of method M were 77％,81％ and 80％,respectively,and there was significant difference between the two methods.There was no significant difference in the parameters of difficult laryngoscopy which were predicted using method U between the patients of different ages or gender.Conclusion It can accurately predict the difficult laryngoscopy in the obese patients when the ultrasound-measured quantification of anterior neck soft tissue is greater than 20 mm.

Efficacy of fascia iliaca compartment block with dexmedetomidine combined with ropivacaine for analgesia in patients suffering from proximal femoral fractures / 中华麻醉学杂志

Objective To evaluate the efficacy of fascia iliaca compartment block with dexmedetomidine combined with ropivacaine for analgesia in the patients suffering from proximal femoral fractures.Methods Eighty emergency patients with proximal femoral fractures,aged 25-70yr,weighing 55-82 kg,of ASA physical status Ⅰ-[Ⅲ,were equally and randomly divided into 2 groups using a random number table:ropivacaine group (group R) and dexmedetomidine mixed with ropivacaine group (group DR).All the patients underwent fascia iliaca compartment block described by Dalens.0.4％ ropivacaine 30 ml was injected in group R,and 1 μg/kg dexmedetomidine 30 ml containing 0.4 ％ ropivacaine was injected in group DR.The severity of pain was assessed by VAS scores,and the level of sedation was assessed by Ramsay scores.At 30,60,90 and 120 min after injection (T1-4),VAS scores at rest and during activity were recorded,the effective analgesia (VAS scores at rest and during activity≤6) and satisfactory sedation (Ramsay scores 2-4) in group DR were also recorded,and the development of hemorrhage or hematoma at the puncture site,local anesthetic poisoning,adverse cardiovascular events and over-sedation was also recorded.Results Compared with group R,the rate of effective analgesia during activity was significantly increased at T2-4,and no significant change was found in the rate of effective analgesia at rest in group DR.In group DR,the rate of satisfactory sedation was 73 ％,88％,95％ and 95％ at T1-4,respectively,and no over-sedation occurred.No patients developed hemorrhage or hematoma at the puncture site,or local anesthetic poisoning in the two groups.Conclusion Fascia iliaca compartment block with 1 μg/kg dexmedetomidine combined with 4％ ropivacaine 30 ml can alleviate the early pain caused by passive activity without inducing obvious adverse reactions in the patients suffering from proximal femoral fractures.

Accuracy of loss of resistance technique for location of fascia iliaca compartment : evaluation using ultrasound technique / 中华麻醉学杂志

Objective The evaluate the accuracy of loss of resistance technique for location of fascia iliaca compartment using ultrasound technique.Methods One hundred and seventy-five patients undergoing hip surgery were enrolled in the study.A line was drawn on the skin from the pubic tubercle to the anterior superior iliac spine and divided in three equal parts.The site of puncture was marked 2 cm distal to the point at which the lateral met the middle third of the line.The needle was inserted until a loss of resistance was felt twice (fascia lata and fascia iliaca),at which point 0.5 ％ ropivacaine 30 ml was infused.Correct puncture was identified by visualized spread of local anesthetic solution under the guidance of ultrasound technique.The effective sensory block was recorded within 20 min after administration.Results The accuracy of loss of resistance method for locating the fascia iliac compartment was 56.6 ％ using ultrasound technique.There were 80 patients in whom fault site of puncture occurred:25 cases in the superficial layer of the fascia iliac and 51 cases in the iliopsoas muscle.The rate of effective block was 98.0 ％ for correct location and 82.9 ％ for fault location.Conclusion Loss of resistance technique cannot accurately locate the fascia iliac compartment.