Yun Jeong Chae

Intravascular Flow Patterns in Transforaminal Epidural Injections: A Comparative Study of the Cervical and Lumbar Vertebral Segments

BACKGROUND: Transforaminal epidural injection (TEI) is commonly used in the treatment of radicular pain. However, there have been many published cases of serious complications after a TEI, occurring most often in cervical levels. One of the presumptive reasons for this complication is inadvertent intravascular injection. We sought to identify the incidence of intravascular injections in cervical and lumbar spinal segments during TEI. METHODS: All patients with radicular symptoms or herpes zoster-associated pain underwent cervical and lumbar TEIs (LTEIs) prospectively by one of the authors. After an ideal needle position was confirmed by biplanar fluoroscopy, 3 mL of a mixture containing nonionic contrast and normal saline was continuously injected at the rate of 0.3–0.5 mL/s with real-time fluoroscopic visualization. RESULTS: One hundred eighty-two TEIs were performed. Fifty-six cases (30.8%) showed intravascular spreading patterns, 45 cases occurring during a cervical TEI (CTEI) and 11 during a LTEI. The incidences of simultaneous perineural and vascular injection in cervical and LTEIs were 52.1% and 9%, respectively, and pure vascular flow pattern rates in cervical and LTEIs were 11.3% and 0.9%, respectively. CONCLUSION: The incidence of vascular injection in CTEIs is significantly higher than in LTEIs, suggesting that CTEIs should be performed more cautiously. Furthermore, the vascular injection rate of CTEIs is much higher than that previously reported. This finding suggests the need for a proper volume of contrast injection (3 mL) to detect vascular flow, especially in simultaneous perineural and vascular injections.

Efficacy and safety of high concentration lidocaine for trigeminal nerve block in patients with trigeminal neuralgia

Aims:  Local anaesthetics, which act as neurolytics and Na+ channel blockers, have been used for disrupting the neural firings in certain neuropathic pain conditions. This study was undertaken to investigate the clinical outcome of trigeminal nerve block with 10% lidocaine in the management of trigeminal neuralgia (TN).

The optimum bolus dose of remifentanil to facilitate laryngeal mask airway insertion with a single standard dose of propofol at induction in children.

The purpose of this study was to determine the optimal bolus dose of remifentanil required for the successful insertion of the laryngeal mask airway during propofol induction in children without a neuromuscular blocking agent. Twenty‐six paediatric patients, aged 3–10 years, requiring anaesthesia for short ambulatory surgery were recruited. A predetermined bolus dose of remifentanil was injected over 30 s, followed by propofol 2.5 mg.kg−1 over 10 s. The bolus dose of remifentanil was determined by a modified Dixon’s up‐and‐down method, starting from 0.5 μg.kg−1 (0.1 μg.kg−1 as a step size). Laryngeal mask insertion was attempted 90 s after the end of remifentanil injection and the response of patients was classified as either ‘movement’ or ‘no movement’. The bolus dose of remifentanil at which there was a 50% probability of successful laryngeal mask insertion (ED50) during induction with 2.5 mg.kg−1 propofol was 0.56 (0.07) μg.kg−1 in children without a neuromuscular blocking agent. From probit analysis, the ED50 and ED95 of remifentanil were 0.52 μg.kg−1 (95% confidence limits, 0.42–0.62 μg.kg−1) and 0.71 μg.kg−1 (95% confidence limits, 0.61–1.40 μg.kg−1), respectively.

Intravenous lidocaine pretreatment with venous occlusion for reducing microemulsion propofol induced pain: Comparison of three doses of lidocaine

Objective Pretreatment with intravenous 40 mg or 0.5 mg/kg lidocaine with venous occlusion is recommended to prevent pain following injection of lipid emulsion propofol. This approach is not sufficient to prevent pain from the injection of microemulsion propofol. The present study investigated whether a higher dose of lidocaine pretreatment with venous occlusion would be more effective for reducing pain following injection of microemulsion propofol compared with 40 mg lidocaine. Methods Patients undergoing elective surgery were randomly assigned to one of three groups: pretreatment with 40 mg (group L40), 60 mg (group L60) or 80 mg (group L80) lidocaine intravenously with venous occlusion, followed by injection with microemulsion propofol 1 min later. Pain was assessed on a four-point scale (severe, moderate, mild, none) based on physical responses to the injection. Results A total of 68 patients were included in the final analysis. Pain severity and incidence were significantly lower in patients in group L60 and L80 compared with patients in group L40. There were no statistically significant differences in pain incidence or severity between group L60 and group L80. Conclusions Pretreatment with 60 mg lidocaine intravenously with venous occlusion may be the most effective minimum dose for reducing injection pain following microemulsion propofol administration for induction of anaesthesia.

Disconnection Technique With a Bronchial Blocker for Improving Lung Deflation: A Comparison With a Double-Lumen Tube and Bronchial Blocker Without Disconnection

OBJECTIVE One-lung ventilation (OLV) is accomplished with a double-lumen tube (DLT) or a bronchial blocker (BB). The authors compared the effectiveness of lung collapse using DLT, BB, and BB with the disconnection technique. DESIGN Prospective, randomized, blind trial. SETTING A university hospital. PARTICIPANTS Fifty-two patients undergoing elective pneumothorax surgery. INTERVENTIONS Patients were assigned randomly to 1 of 3 groups: The DLT group (group 1), the BB group (group 2), and the BB with the disconnection technique group (group 3). The authors modified the disconnection technique in group 3 as follows: (1) turned off the ventilator and opened the adjustable pressure-limiting valve, allowing both lungs to collapse and (2) after loss of the CO2 trace on the capnograph, inflated the blocker cuff and turned on the ventilator, allowing only dependent-lung ventilation. MEASUREMENTS AND MAIN RESULTS Five and ten minutes after OLV, the degree of lung collapse was assessed by the surgeon, who was blinded to the isolation technique. The quality of lung collapse at 5 and 10 minutes was significantly better in groups 1 and 3 than in group 2. No significant differences were observed for the degree of lung collapse at any time point between groups 1 and 3. The average time for loss of the CO2 trace on the capnograph was 32.3±7.0 seconds in group 3. CONCLUSIONS A BB with spontaneous collapse took longer to deflate and did not provide equivalent surgical exposure to the DLT. The disconnection technique could be helpful to accelerate lung collapse with a BB.

Combination of nitrous oxide and lidocaine to prevent withdrawal after rocuronium in children

Background Pain at the site of rocuronium injection is a common side-effect in pediatric patients. This prospective, randomized, double-blind study evaluated the efficacy of a combination of nitrous oxide and lidocaine pretreatment on withdrawal response during rocuronium injection in children. Methods Sixty six pediatric patients, ages 5 to 12 years, were randomly assigned to two groups. The oxygen group received 100% oxygen, and the nitrous oxide group received 50% N2O in oxygen over 2 min. After anesthesia was induced with 2.5% thiopental sodium 5 mg/kg and manual occlusion of the forearm was performed, 1% lidocaine 1 mg/kg was injected over 15 sec. After the occlusion was released, 0.1% rocuronium 0.6 mg/kg was injected over 5 sec. Patient response to rocuronium injection was graded using a 4-point scale. Results Overall incidence of withdrawal movements was significantly lower in the nitrous oxide group (1 patients; 3.1%) than in the oxygen group (8 patients; 25.8%) (P = 0.013). No patient in the nitrous oxide group displayed arm or generalized movement (grade 3 or 4) associated with rocuronium injection. Conclusions This study demonstrated that a combination of inhaled 50% N2O in O2 and 1 mg/kg lidocaine pretreatment significantly reduced the incidence of rocuronium-induced withdrawal movements in pediatric patients compared with lidocaine pretreatment alone.

Trigeminal nerve block with alcohol for medically intractable classic trigeminal neuralgia: long-term clinical effectiveness on pain

Background: Trigeminal nerve block (Tnb) with alcohol for trigeminal neuralgia (TN) may not be used widely as a percutaneous procedure for medically intractable TN in recent clinical work, because it has been considered having a limited duration of pain relief, a decrease in success rate and increase in complications on repeated blocks. Objectives: To evaluate the clinical outcome of the Tnb with alcohol in the treatment of medically intractable TN. Methods: Six hundred thirty-two patients were diagnosed with TN between March 2000 and February 2010. Four hundred sixty-five out of 632 underwent Tnb with alcohol under a fluoroscope. Pain relief duration were analyzed and compared in the individual branch blocks. Outcomes were compared between patients with and without a previous Tnb with alcohol. Results: Tnb with alcohol were performed in a total 710 (1st-465, 2nd-155, 3rd-55, 4th-23, 5th-8, 6th-4) cases for a series of consecutive 465 patients during the study period. Forty hundred sixty two out of the 465 patients experienced immediate complete pain relief (99%) at the first Tnb. Of the 465 patients, 218 patients (46.9%) did not require any further treatment after the first Tnb with alcohol during an entire study period. One hundred fifty nine (34.2 %) out of the 465 patients experienced recurring pain after the first block, among whom 155 patients received subsequent blocks, and the remaining 4 patients decided to take medication. According to the Kaplan-Meier analysis, the probabilities of remaining pain relief for 1, 2, 3, and 5 years after the procedures were 86.2%, 65.5%, 52.5%, and 33.4%, respectively. There was no significant difference in the probability of pain relief duration between patients with and without previous Tnb with alcohol. Median (95% CI) pain relief durations of the first and repeated blocks were 39 (36-51) and 37 (28-54) months, respectively. There was no significant difference in occurrence of complications between patients with and without previous Tnb with alcohol (p <0.076). All the complications recovered spontaneously within 6 months. There was no mortality related to the procedure. Conclusions: Tnb with alcohol for the pain management of TN can provide considerably long lasting pain relief. Repeated Tnb with alcohol has pain relief duration as long as the first block, and seems to produce less complication as well. Tnb with alcohol is a valuable treatment modality of TN as a percutaneous procedure.

A target-controlled infusion regimen for reducing remifentanil-induced coughs

Background This study evaluates the effectiveness of the target-controlled infusion (TCI) of remifentanil through stepwise increases in the effect-site concentration (Ceff) in preventing coughs. Methods In a preliminary study, we randomly selected 140 patients to receive remifentanil through two-step increases in Ceff (1.0 ng/ml to 4.0 ng/ml: Group R1-4; 2.0 ng/ml to 4.0 ng/ml: Group R2-4). Based on the results of the preliminary study, we employed another sample of 140 patients and implemented a three-step increase in TCI (1.0 ng/ml to 2.0 ng/ml to 4.0 ng/ml: Group R1-2-4). We then compared this treatment with direct targeting based on 4.0 ng/ml TCI (Group R4). We recorded the episodes of coughs, rating them as mild (1-2), moderate (3-4), or severe (5 or more). Results In Group R1-4, one patient (1.5%) coughed during the first step, and five (7.3%) coughed during the second step. In Group R2-4, nine (13.2%) coughed during the first step, but none coughed during the next step. Only one patient had a mild cough during the three-step increase in TCI, that is, patients in Group R1-2-4 were significantly less likely to cough than those in Group R4 (P < 0.001). Conclusions Stepwise increases in the TCI of remifentanil reduced the incidence of remifentanil-induced coughing, and the three-step increase in TCI nearly eliminated remifentanil-induced coughing.

Paraplegia following cervical epidural catheterization using loss of resistance technique with air: a case report

We report a case of paraplegia without neurologic deficit of upper extremities following cervical epidural catheterization using air during the loss of resistance technique. A 41-year-old woman diagnosed with complex regional pain syndrome had upper and lower extremity pain. A thoracic epidural lead was inserted for a trial spinal cord stimulation for treating lower extremity pain and cervical epidural catheterization was performed for treating upper extremity pain. Rapidly progressive paraplegia developed six hours after cervical epidural catheterization. Spine CT revealed air entrapment in multiple thoracic intervertebral foraminal spaces and surrounding epidural space without obvious spinal cord compression before the decompressive operation, which disappeared one day after the decompressive operation. Her paraplegia symptoms were normalized immediately after the operation. The presumed cause of paraplegia was transient interruption of blood supply to the spinal cord through the segmental radiculomedullary arteries feeding the spinal cord at the thoracic level of the intervertebral foramen caused by the air.

Effect-site concentration of remifentanil for smooth inhalational induction with desflurane

Objective To determine the effect-site concentration (Ce) of remifentanil target-controlled infusion required for a smooth inhalational induction without airway irritation using desflurane in a stepwise incremental manner for 50% of patients (EC50) and 95% of patients (EC95). Methods Patients with an American Society of Anesthesiologists physical status I and II, aged 19–60 years undergoing elective surgery were enrolled in this study. When target Ce of remifentanil was reached, desflurane was inhaled at 4 vol% initially and then it was increased to 8 and 12 vol% at intervals of 30 s. Smooth induction was regarded as an absence of airway irritation signs and excitatory movements. The EC50 and EC95 values for remifentanil were determined using a modified Dixon’s up-and-down method as well as an isotonic regression method with a bootstrapping approach. Results The EC50 and EC95 of remifentanil for smooth induction during inhalation of desflurane were 3.40 ng/ml (95% confidence interval [CI] 2.42, 4.38 ng/ml) and 4.31 ng/ml (95% CI 2.15, 5.98 ng/ml), respectively. Conclusion Prior administration of remifentanil could provide smooth inhalational induction with desflurane in a stepwise increment.