Optimization of Intraoperative Neural Monitoring of the Recurrent Laryngeal Nerve in Thyroid Surgery.

The application of intraoperative neural monitoring (IONM) has been widely accepted to improve surgical outcomes after thyroid surgery. The malfunction of an IONM system might interfere with surgical procedures. Thus, the development of anesthesia modalities aimed at ensuring functional neuromonitoring is essential. Two key issues should be taken into consideration for anesthetic management. Firstly, most patients undergo recurrent laryngeal nerve monitoring via surface electrodes embedded in an endotracheal tube. Thus, advanced video-assisted devices might optimize surface electrode positioning for improved neuromonitoring signaling accuracy. Secondly, neuromuscular blocking agents are routinely used during thyroid surgery. The ideal neuromuscular block should be deep enough for surgical relaxation at excision and recovered enough for an adequate signal f nerve stimulation. Proper neuromuscular block management could be achieved by titration doses of muscle relaxants and reversal agents.

Combination Preemptive Peripheral Nerve Block in Limb Surgery. A Prospective Study.

Background and objectives: Patients often suffer from moderate to severe pain during the early recovery period in orthopedic surgery. We investigated the impact of a single-shot preoperative peripheral nerve block (PNB) on post-anesthesia recovery parameters and interleukin (IL)-6 level during limb surgery. Materials and Methods: A prospective randomized controlled study was conducted, and patients scheduled for limb surgery were recruited. Sixty patients were randomly assigned to either the PNB group or control group, who received morphine as a primary analgesic. The peak verbal numeric rating scale (NRS) score in the post-anesthesia care unit (PACU) was evaluated as a primary outcome. We also recorded rescue analgesics requirement and wake-up time from anesthesia in the PACU. In addition, the change of plasma IL-6 level after incision was measured. Results: Fifty-two patients completed the study, 27 and 25 cases in the PNB and control group, respectively. Preemptive PNB significantly reduced peak NRS score in the PACU compared to control group. Lower rescue analgesics requirement and rapid wake-up from anesthesia were also noted in PNB group. The IL-6 concentration increased less in the PNB group at 2 h after incision. Conclusions: Preemptive PNB attenuates IL-6 expression 2 h after incision and improves pain management in the PACU. PNB was considered as an essential part of pain management in limb surgery.

The Effectiveness of Low-dose Dexmedetomidine Infusion in Sedative Flexible Bronchoscopy: A Retrospective Analysis.

Background and objectives: Flexible bronchoscopy has been widely used for diagnosis and intervention, while various drugs are used for sedation during bronchoscopy. We examined two regular standardized sedation options (with or without dexmedetomidine) regularly used in our regional hospital. The aim was to assess the efficacy and safety of dexmedetomidine on conscious sedation under bronchoscopy. Materials and Methods: A retrospective chart review was conducted from April 2017 to March 2018. All patients undergoing flexible bronchoscopy with moderate sedation were enrolled. Patients having received dexmedetomidine-propofol-fentanyl were defined as group D, and those having received midazolam-propofol-fentanyl were defined as group M. The primary outcome was a safety profile during the procedure, including the incidence of procedural interference by patient cough or movement, transient hypoxemia, and hypotension. The secondary outcome was measured by the recovery profile (awake and ambulation time). Results: Thirty-five patients in group D and thirty-three in group M were collected in this retrospective study. All patients underwent the procedure successfully. Group D showed higher safety with fewer procedural interference incidences by cough or body movement than Group M (3.3% versus 36.3%, p < 0.001) and minor respiratory adverse effects. Patients in group D showed faster recovery in a shorter ambulation time than group M (24.9 ± 9.7 versus 31.5 ± 11.9, p = 0.02). In group D, bronchoscopist satisfaction to sedation was higher than group M (p = 0.01). More transient bradycardia episodes were noted in patients receiving dexmedetomidine (p < 0.05), but all recovered without atropine intervention. Overall post-procedural adverse events and satisfaction were comparable in the two groups. Conclusions: The co-administration of dexmedetomidine met the safety and recovery demands of flexible bronchoscopy. Compared to the conventional midazolam-propofol-fentanyl regimen, the application of dexmedetomidine improved sedative effectiveness with less procedural interruptions, shorter time to ambulation and higher bronchoscopist satisfaction.

Propofol target-controlled infusion for sedated gastrointestinal endoscopy: A comparison of propofol alone versus propofol-fentanyl-midazolam.

Gastrointestinal (GI) endoscopy is the major technique for diagnosis of GI disease and treatment. Various sedation and analgesia regimens such as midazolam, fentanyl, and propofol can be used during GI endoscopy. The purpose of the study was to compare propofol alone and propofol combination with midazolam and fentanyl in moderate sedation for GI endoscopy. One hundred patients undergoing GI endoscopy were enrolled in this study. All patients received a propofol target-controlled infusion (TCI) to maintain sedation during the procedure. Patients were randomly allocated into either Group P (propofol TCI alone) or Group C (combination of propofol TCI plus midazolam and fentanyl). Dermographic data, anesthetic parameters (sedation regimen, blood pressure, heart rate, and oxygen saturation), procedure parameters (procedure time, colonoscopy, or panendoscopy), propofol consumption, and adverse events (hypoxia, hypotension, and bradycardia) were all recorded. Postprocedural records included recovery time, postoperative adverse events (nausea, vomiting, dizziness, recall, and pain) and satisfaction. The average propofol consumption was 251 ± 83 mg in Group P and 159 ± 73 mg in Group C (p < 0.001). The incidence of transient hypotension was higher in Group P (p = 0.009). The recovery time and discharge time were both shorter in Group C (p < 0.001 and p = 0.006 respectively). Overall, postprocedural adverse events were similar in both groups. The postanesthetic satisfaction was comparable in both groups. TCI of propofol combined with midazolam and fentanyl achieved sedation with fewer hypotension episodes and shorter recovery and discharge time than propofol TCI alone in patients undergoing GI endoscopy.

Soft catheters reduce the risk of intravascular cannulation during epidural block--a retrospective analysis of 1,117 cases in a medical center.

A wet or bloody tap is an inevitable complication while performing epidural block. The influence of different catheters on the incidence of intravascular cannulation during epidural catheterization has not been reported. We observed an initial, relatively different incidence of intravascular cannulation during the placement of different sorts of epidural catheter; hence, a retrospective review was conducted to explore the possible association. We reviewed 1-year interval anesthetic records of 1117 patients who had undergone epidural anesthesia or received patient-controlled epidural analgesia. Epidural catheter placement was performed by a loss of resistance technique with an 18-G Tuohy needle in lateral position. Patients were divided into two groups according to the different types of epidural catheters used (Perifix One, n=590; Perifix Standard, n=527). Primary outcome measurement was the incidence of intravascular injection. Other analyzed outcomes included dura puncture, failure rate, and low back pain. The incidence of epiduralintravascular cannulation was significantly lower using the Perifix One catheter (1.5%; 9/590) than using the Perifix Standard (4.6%; 24/527), p=0.003. The dura puncture rate did not differ significantly between the Perifix One (1.9%; 11/590) and the Perifix Standard (2.5%; 13/527), p=0.49. Failure rates and low back pain incidence were also comparable between the two groups. Application of the soft epidural catheter (Perifix One) may reduce the incidence of epidural intravascular cannulation. We suggest the use of Perifix One catheter instead of Perifix Standard catheter in daily practice.

A modified lightwand-guided nasotracheal intubation technique for oromaxillofacial surgical patients.

STUDY OBJECTIVE: To investigate the efficiency of a double curve nasotracheal tube on lightwand-guided nasotracheal intubation. DESIGN: Prospective, randomized, controlled trial. SETTING: University medical center hospital. PATIENTS: 60 ASA physical status I and II patients undergoing oromaxillofacial surgery. INTERVENTIONS AND MEASUREMENTS: Patients undergoing surgery with nasotracheal intubation and general anesthesia were randomly enrolled in the laryngoscopy group or the lightwand group. The same type of double curve nasotracheal tube was used in both groups. In the laryngoscopy group, intubation was assisted with a Macintosh No. 3 standard curved blade and Magill forceps. In the lightwand group, intubation was aided with a flexible lightwand device (without the inner stiff stylet). Intubation time was divided into two parts: Part one, from selected naris to oropharynx; Part two, from oropharynx into trachea. Part one, Part two, and total intubation time, hemodynamic responses to nasotracheal intubation, and adverse events or complications were recorded. MAIN RESULTS: Total intubation times in the lightwand group and the laryngoscopy group were 22.8 +/- 8.0 sec vs 30.3 +/- 8.2 sec (P < 0.001), respectively. The lightwand group had comparable hemodynamic responses to those of the laryngoscopy group. Adverse events and complications were all self-limited, with similar occurrence in both groups. CONCLUSION: For patients undergoing oromaxillofacial surgery, modified lightwand-guided nasotracheal intubation is feasible with a double curve nasotracheal tube and is an efficient alternative technique.

Ultrasound examination for the optimal head position for interscalene brachial plexus block.

BACKGROUND: Surface anatomic landmarks have traditionally been used to locate the brachial plexus in the interscalene groove. Head rotation can affect the orientation of neck vessels and may possibly affect the brachial plexus. The optimal degree of head rotation has been specified for better internal jugular vein cannulation but not for interscalene brachial plexus block. The purpose of this study was to evaluate the influence of head rotation on interscalene brachial plexus block. METHODS: We simulated the needle insertion in interscalene approach to brachial plexus with the ultrasound probe to mimic the needle in the manner of actual block in 53 volunteers. Ultrasound-derived measurements were recorded to evaluate the influence of head rotation on the approach including deviation from the imitative needle path to plexus center, depth of brachial plexus and vessel intersection. RESULTS: Medial deviation of the imitative needle path to the center of brachial plexus was found from all angles of head rotation. Increased head rotation angle of 0 degree, 15 degrees, 30 degrees, 45 degrees and 60 degrees from the midline was associated with increasing medial deviation. The brachial plexus became more superficial if head rotation was over 30 degrees than within the realm of 15 degrees. The likelihood of the stimulated needle path intersecting the internal jugular vein was lower than 5% for head rotation within 30 degrees and would become significantly higher for head rotation over 45 degrees. CONCLUSIONS: Whenever we perform interscalene brachial plexus block, the head rotation angle should not exceed 30 degrees. The measured medial deviation of surface landmark should be considered when it is used to approach interscalene brachial plexus.

Clinical experience of pain treatment for postherpetic neuralgia in elderly patients.

BACKGROUND: Postherpetic neuralgia (PHN) is a neuropathic pain syndrome that occurs following acute herpes zoster infection. The main clinical problem is intractable pain which interferes with activity of daily life and reduces the quality of life in the elderly patients. This retrospective study was to evaluate the outcome of pain treatment for the elderly patients with PHN at the Pain Clinic of Kaohsiung Medical University Hospital. METHODS: Fifty-eight elderly outpatients with PHN were studied from January 2004 to June 2006. The pain intensity before and after treatment were assessed by patients themselves with numeric pain scale (NPS). The pain treatment included (1) medication with anticonvulsants, opioids and nonsteroidal anti-inflammatory drugs (NSAIDs); (2) nerve block with 0.25% bupivacaine or 1% lidocaine twice a week at the beginning of the treatment. The therapeutic outcome was expressed by pain relief. The reduction of pain and residual pain intensity were evaluated subjectively by the patients themselves with patients' global impression and NPS, respectively, after treatment for one and three months (or last visit). The adverse events throughout the treatment course were analyzed. RESULTS: (1) The mean age of the patients was 75.1 yr. The number of female PHN sufferers was higher than that of male in all aged groups and the highest incidence was found in the age group of 70-79 (65.5%). The most commonly involved dermatomes were in the thoracic region (82.7%). (2) All patients suffered from severe pain (NPS 8-10) before treatment. (3) The pain management was a combination of medication and nerve block at the beginning of the treatment. Among the medications, gabapentin was prescribed to all the patients and almost all of them (98.3%) required opioids simultaneously and some of them needed additional NSAIDs at the beginning of the treatment. (4) The most common adverse event was somnolence (24.1%). (5) Among the sympathetic blocks, the intercostal nerve block was performed commonly (84.5%). (6) The therapeutic outcome was expressed by pain relief. As to the reduction of pain, 46 cases (79.3%) and 57 cases (98.3%) felt moderate and much improvement after treatment for one and three months (or last visit), respectively. As to residual pain intensity, although none of them got complete pain relief, however, there were 12 cases (20.7%) and 45 cases (77.6%) felt the pain intensity was mild (NPS 1-3) after treatment for one and three months respectively. (7) There was a statistically significant decrease in the pain intensity between before treatment and after treatment for one month and three months. CONCLUSIONS: Our study results showed that the concurrent combination therapy with proper medications and appropriate nerve blocks could offer satisfactory pain relief in the majority of elderly patients with PHN.

The feasibility of surface landmark for coracoid infraclavicular brachial plexus block by ultrasonographic assessment.

BACKGROUND: The coracoid infraclavicular block first introduced by Whiffler provides a safer and easily approach than classic infraclavicular block. In this technique, the anatomy-based puncture site is 2 cm medial and 2 cm caudal from the coracoid process. This prospective study was purposed to evaluate the feasibility of surface landmark-based coracoid block by ultrasonography. METHODS: High-frequency ultrasonographic examination was performed in 80 volunteers along the vertical line 2 cm medial to the coracoid process. The C point (C) is defined as landmark-based puncture site. The U point (U) is defined as the ultrasonographically modified optimal puncture site. After identifying the neurovascular bundle, the extent of precision based on landmark was examined and ultrasonographic measurements were also done. Demographic data was applied to correlate with the deviation between C and U. RESULTS: The landmark-based puncture site for coracoid infraclavicular block was found to have a fair precision rate of 74.4%, although not high enough to provide a reliable puncture in daily practice. There was a significant trend toward a more superior puncture site of 2.95 mm (95% CI, 1.2-4.7). In female subjects, U was 5.12 mm (95% CI, 2.91-7.33) superior to C which was statistically significantly (P < 0.001). In male subjects, U was not significantly superior to C. CONCLUSIONS: Ultrasonographic guidance is suggested whenever anatomical precision is inadequate or meeting with great individual bodily variance which renders landmark-based technique difficult. However, if this facility is not available, the gender discrepancy in measurement should be seriously considered when coracoid process is used as the landmark.

Seizure after local anesthesia for nasopharyngeal angiofibroma.

We report a young male patient who experienced seizure after local injection of 3 mL 2% lidocaine with epinephrine 1:200,000 around a recurrent nasal angiofibroma. After receiving 100% oxygen via mask and thiamylal sodium, the patient had no residual neurologic sequelae. Seizure immediately following the injection of local anesthetics in the nasal cavity is probably due to injection into venous or arterial circulation with retrograde flow to the brain circulation. Further imaging study or angiography should be done before head and neck surgeries, especially in such highly vascular neoplasm.