Lower extremity peripheral nerve block for total knee arthroplasty in a patient with chronic inflammatory demyelinating polyneuropathy: A case report.

RATIONALE: Chronic inflammatory demyelinating polyneuropathy (CIDP) is an autoimmune disorder that affects the peripheral nerves, leading to weakness and sensory symptoms. CIDP is a rare disease, and few studies have reported on anesthetic management in patients with this condition, especially the peripheral nerve block (PNB). Therefore, a safe and standardized anesthetic approach remains to be established. This case report aims to address this gap in evidence by documenting our experience with PNB in a patient with CIDP undergoing surgery. It contributes significantly to expanding the range of anesthetic options and enhancing perioperative outcomes for patients with CIDP. PATIENT CONCERNS: A 58-year-old woman diagnosed with CIDP was scheduled to undergo left total knee arthroplasty due to osteonecrosis. We anticipated postoperative pain and aggravation of neurological symptoms. DIAGNOSIS: CIDP. INTERVENTIONS: To manage the postoperative pain, we planned a combination of general anesthesia (GA) and lower extremity PNBs, viz. the tibial and femoral nerve blocks, supplemented with intravenous patient-controlled analgesia. An initial dose of fentanyl 50 µg was administered as analgesia. The tibial and femoral nerves were identified using a peripheral nerve stimulator in conjunction with an ultrasonic echo device while the patient was conscious, to minimize the risk of nerve injury. The tibial and femoral nerve blocks were performed with 20 mL of ropivacaine (0.25%) and dexamethasone 2.2 mg, respectively. Subsequently, we administered fentanyl and ketamine and initiated continuous infusion of remifentanil. Thereafter, propofol 120 mg was administered intravenously over a span of 1 minute, followed by continuous infusion at 4 mg/kg/h. Upon confirming loss of consciousness, we induced GA using a supraglottic airway device without using muscle relaxants. For postoperative analgesia, we administered acetaminophen 1000 mg. OUTCOMES: The patient experienced no pain immediately after surgery, and good analgesia was achieved subsequently without worsening of sensory symptoms during rehabilitation. LESSONS: We achieved effective anesthetic management in a patient with CIDP by combining GA with nerve stimulation and ultrasound-guided PNB. It is crucial to devise a personalized anesthesia plan that focuses on the patients' safety and comfort while minimizing risk in patients with CIDP.

Effective anesthetic management with remimazolam and ketamine without muscle relaxants for parotidectomy in a patient with myotonic dystrophy: A case report.

RATIONALE: Patients with myotonic dystrophy (DM) are highly sensitive to anesthetics, muscle relaxants, and opioids, necessitating appropriate anesthetic management. Recently, remimazolam, an ultra-short-acting benzodiazepine, has been approved for use as a general anesthetic in Japan, and patients with DM have reportedly been treated with remimazolam. However, to the best of our knowledge, no study has reported on endotracheal intubation without the use of muscle relaxants under anesthetic management with remimazolam, nor on the combination of remimazolam and ketamine. PATIENT CONCERNS: A 23-year-old man was referred to our hospital for right parotidectomy and diagnosed with DM just before surgery. At the surgeon's discretion, he was scheduled to undergo nerve monitoring to preserve the facial nerve. DIAGNOSIS: Myotonic dystrophy. INTERVENTIONS: We planned total intravenous anesthesia without muscle relaxants and selected remimazolam for anesthesia. Our aim was to prevent the intraoperative or postoperative complications associated with propofol and inhalational anesthetics. Additionally, we selected multimodal analgesia, including ketamine, to avoid opioid use. General anesthesia was induced with ketamine 30 mg, remifentanil 0.72 µg/kg/min, and remimazolam 12 + 6 mg. Endotracheal intubation was performed under videolaryngoscopy without the use of muscle relaxants. For postoperative analgesia, we administered additional doses of ketamine 20 mg and acetaminophen 1000 mg, and the surgeons infiltrated 8 mL of xylocaine 0.5% with epinephrine into the skin incision before starting the surgery. Intraoperative anesthesia was maintained with remimazolam 0.9 to 1.0 mg/kg/h and remifentanil 0.26 to 0.50 µg/kg/min. Flumazenil was administered for rapid awakening and safe extubation. All vitals, including the bispectral index, were stable during surgery. OUTCOMES: The patient did not develop facial nerve paralysis, sore throat, or hoarseness, nor did he have any memory of the surgery. Good postoperative analgesia was achieved. LESSONS: We achieved effective anesthetic management using remimazolam without muscle relaxants in a patient with DM. Furthermore, the combination of remimazolam and ketamine provided good sedation and postoperative analgesia.

Accidental epidural catheter removal rates and strength required for disconnection: a retrospective cohort and laboratory study.

BACKGROUND: Epidural catheters are associated with certain risks such as accidental epidural catheter removal, including dislodgement and disconnection. Globally, neuraxial connector designs were revised in 2016 to provide new standardization aimed at decreasing the frequency of misconnections during the administration of medications. However, no studies have investigated accidental epidural catheter removal after the revised standardization. This study aimed to examine differences in dislodgement and disconnection rates associated with different catheter connector types, and to investigate the linear tensile strength required to induce disconnection. METHODS: This retrospective cohort study included adult patients who underwent elective surgery and received patient-controlled epidural analgesia. Patients were divided into groups according to the type of catheter connection used: old standard, new standard, and new standard with taping groups. Furthermore, we prepared 60 sets of epidural catheters and connectors comprising 20 sets for each of the old, new, and taping groups, and used a digital tension meter to measure the maximum tensile strength required to induce disconnection. RESULTS: This clinical study involved 360, 182, and 378 patients in the old, new, and taping groups, respectively. Dislodgement rates did not differ statistically among the three groups, while there was a significant difference in disconnection rates. Propensity score matching analysis for disconnection rates showed no difference between the old and new groups (2.8% vs. 4.5%, p = 0.574), while the new group had higher rates than the taping group (6.5% vs. 0%, p = 0.002). This laboratory study identified that a tensile strength of 12.41 N, 12.06 N, and 19.65 N was required for disconnection in the old, new, and taping groups, respectively, and revealed no significant difference between the new and old groups (p = 0.823), but indicated a significant difference between the new and taping groups (p < 0.001). CONCLUSIONS: This clinical study suggested that dislodgement rates did not change among the three groups. Both clinical and laboratory studies revealed that disconnection rates did not change between the old and new connectors. Moreover, as a strategy to prevent accidents, taping the connecting points of the catheter connectors led to an increase in the tensile strength required for disconnection.

Comparison of surgical outcomes between laparoscopic percutaneous extracorporeal closure (LPEC) and open repair for pediatric inguinal hernia by propensity score methods and log-rank test analysis.

BACKGROUND: Despite a number of studies comparing laparoscopic inguinal hernia repair (LH) and open herniorrhaphy (OH), the putative advantage of LH remains controversial due to a paucity of firm evidence. We hypothesized that LH has both advantages and disadvantages compared to OH and sought to clarify them by comprehensively analyzing the retrospective data using the combination of multiple statistical methods. METHODS: Operative data for inguinal hernia during the period from February 1999 to December 2019 were examined. The patients were assigned into two groups according to the surgical procedure: laparoscopic percutaneous extraperitoneal closure (LPEC, n = 2410) and OH (n = 2038). Operative and anesthesia times and incidence of postoperative complications were evaluated using the propensity score methods and log-rank test. RESULTS: In comparison with OH, operative time of LPEC was longer for unilateral repair (21.59 ± 8.1 min vs 18.01 ± 8.0 min; p < 0.001) and shorter for bilateral repairs (28.55 ± 10.1 min vs 33.23 ± 11.7 min; p < 0.001), while anesthesia times were longer for both unilateral repair (57.67 ± 10.1 min vs 40.62 ± 11.9 min; p < 0.001) and bilateral repairs (65.95 ± 12.5 min vs 56.35 ± 15.1 min; p < 0.001). LPEC significantly reduced the risk of metachronous contralateral hernia (MCLH) (0.52% vs 9.29%; p < 0.001), but the recurrence rate was higher (0.21% vs 0.04%; p = 0.002) than OH. Orchiectomy due to testicular atrophy or torsion was required in 3 cases of OH (0.19%), whereas it was not seen in LPEC. CONCLUSIONS: LPEC had a less risk of MCLH and testicular complications but was associated with a higher recurrence rate and longer anesthesia time. Propensity scoring techniques can enhance the robustness of retrospective comparisons between groups over several years of data collection, which is frequently required in pediatric surgery studies.

Successful peripheral nerve block under dexmedetomidine sedation for femoral neck fracture fixation in a 97-year-old patient.

Hip fracture is a common injury in elderly patients. In Japan, the number of super-old patients-age >90 years-with hip fractures has increased drastically over time. Available strategies for anaesthetic management for hip fracture surgery include general anaesthesia, neuraxial anaesthesia and peripheral nerve block. However, general and neuraxial anaesthesia are often avoided for various reasons, particularly in elderly patients. In recent years, peripheral nerve block has proven effective in various surgical procedures. Additionally, dexmedetomidine exhibits neuroprotective effects and has been used safely in super-old patients. Herein, we demonstrate successful anaesthetic management with peripheral nerve block under dexmedetomidine sedation for open reduction and internal fixation of a femoral neck fracture in a 97-year-old patient.

Distinguishing cerebrospinal fluid from mepivacaine using the pH test in patients undergoing elective cesarean section with combined spinal-epidural anesthesia.

INTRODUCTION: In single-space combined spinal-epidural anesthesia (CSEA), it is important to correctly determine if the fluid coming out of the spinal needle is cerebrospinal fluid (CSF) or the liquid used in the loss of resistance (LOR) technique. In this study, we used mepivacaine for LOR and measured the pH values of CSF and mepivacaine to determine whether the pH test is a reliable method to confirm CSF when performing single-space CSEA. METHODS: This clinical trial included 47 full-term pregnant women who underwent cesarean section. Single-space CSEA was administered at the lumbar intervertebral space using a small amount of mepivacaine for LOR. The pH values of CSF and mepivacaine were determined by the color of the test strip immediately after dropping. The area under the curve (AUC) for the pH values was calculated to determine the cutoff value for distinguishing between CSF and mepivacaine. RESULTS: The median pH values were 7.7 (7.1-8.0) and 6.2 (5.9-6.8) for CSF and mepivacaine, respectively. When the cutoff value of pH for distinguishing CSF from mepivacaine was 7.1 or greater, the AUC was 1.0 (100% sensitivity and specificity). Our result demonstrated that CSF can be correctly distinguished from mepivacaine in patients undergoing cesarean section under single-space CSEA using a cutoff value of pH 7.1. CONCLUSION: The pH test is a simple and reliable method to confirm CSF when performing single-space CSEA with mepivacaine for LOR. TRIAL REGISTRATION: Accuracy of pH test paper for cerebrospinal fluid during spinal anesthesia: prospective study in healthy pregnant women under scheduled caesarean section; University Hospital Medical Information Network, UMIN000036454 . Registered 1 May 2019.

Repeat epidural blood patch at the level of unintentional dural puncture and its neurologic complications: a case report.

BACKGROUND: Autologous epidural blood patch (AEBP) is effective for post-dural-puncture headache (PDPH). In some cases, repeat procedures are required for complete cure. In rare instances, severe adverse effects can occur. We present a case of neurologically complicated AEBPs, one of which was performed at the interspace of unintentional dural puncture (UDP). CASE PRESENTATION: A 40-year-old primigravida sustained UDP at the L2-3 interspace during combined spinal-epidural anesthesia for a scheduled cesarean section. She developed PDPH and underwent a single AEBP at L3-4. The PDPH recurred and she required another AEBP at L2-3, after which she reported radicular pains. A diagnosis of subdural hematoma and adhesive arachnoiditis was made. Her symptoms partially resolved in the following months. CONCLUSION: It may be prudent to reconsider the use of repeated AEBP and to avoid the interspace of UDP. A thorough evaluation is warranted to exclude treatable lesions when adverse effects occur.