Clinical Application of an Augmented Reality Navigation System for Transforaminal Epidural Injection: A Randomized Controlled Trial.

Objectives: Augmented reality (AR) navigation systems are emerging to simplify and enhance the precision of medical procedures. Lumbosacral transforaminal epidural injection is a commonly performed procedure for the treatment and diagnosis of radiculopathy. Accurate needle placement while avoiding critical structures remains a challenge. For this purpose, we conducted a randomized controlled trial for our augmented reality navigation system. Methods: This randomized controlled study involved 28 patients, split between a traditional C-arm guided group (control) and an AR navigation guided group (AR-NAVI), to compare procedure efficiency and radiation exposure. The AR-NAVI group used a real-time tracking system displaying spinal structure and needle position on an AR head-mounted display. The procedural time and C-arm usage (radiation exposure) were measured. Results: All patients underwent successful procedures without complications. The AR-NAVI group demonstrated significantly reduced times and C-arm usage for needle entry to the target point (58.57 ± 33.31 vs. 124.91 ± 41.14, p < 0.001 and 3.79 ± 1.97 vs. 8.86 ± 3.94, p < 0.001). Conclusions: The use of the AR navigation system significantly improved procedure efficiency and safety by reducing time and radiation exposure, suggesting a promising direction for future enhancements and validation.

Development of a Deep Learning Model for the Analysis of Dorsal Root Ganglion Chromatolysis in Rat Spinal Stenosis.

Objective: To create a deep learning (DL) model that can accurately detect and classify three distinct types of rat dorsal root ganglion neurons: normal, segmental chromatolysis, and central chromatolysis. The DL model has the potential to improve the efficiency and precision of neuron classification in research related to spinal injuries and diseases. Methods: H&E slide images were divided into an internal training set (80%) and a test set (20%). The training dataset was labeled by two pathologists using pre-defined grades. Using this dataset, a two-component DL model was developed with the first component being a convolutional neural network (CNN) that was trained to detect the region of interest (ROI) and the second component being another CNN used for classification. Results: A total of 240 lumbar dorsal root ganglion (DRG) pathology slide images from rats were analyzed. The internal testing results showed an accuracy of 93.13%, and the external dataset testing demonstrated an accuracy of 93.44%. Conclusion: The DL model demonstrated a level of agreement comparable to that of pathologists in detecting and classifying normal and segmental chromatolysis neurons, although its agreement was slightly lower for central chromatolysis neurons. Significance: DL in improving the accuracy and efficiency of pathological analysis suggests that it may have a role in enhancing medical decision-making.

Development and Evaluation of a Virtual Reality Simulator for Spinal Cord Stimulation: A Randomized Controlled Trial.

Purpose: The aim of this prospective study was to develop a virtual reality simulator (VRS) for spinal cord stimulation (SCS) trials and establish its effectiveness. Methods: We developed a VRS for SCS training by integrating patient imaging data analytics, creating artificial X-ray images, and using spatial alignment techniques and virtual reality technologies. The simulator was created by a physician with considerable experience in performing SCS, and can simulate the feeling of the procedure in a virtual environment. The efficacy of the simulator for SCS trials was assessed using a cohort of 20 novice trainees. The primary outcomes were duration of the procedure, checklist score, number of C-arm images captured, and overall trainee satisfaction. Results: The cohort that utilized the VRS had better Zwisch scale scores (P <0.001), completed the procedure in a shorter time (P <0.001), took fewer C-arm images (P <0.001), and reported better overall satisfaction (P = 0.011) than the cohort that did not. Conclusion: We developed a realistic and efficient VRS for educating novice trainees on SCS trials, thereby eliminating the risk of radiation exposure associated with cadaver training. The results of this study indicate that our VRS has potential as an instrumental resource that can be integrated into the educational framework for SCS trials.

Efficacy of Transcutaneous 4.4 MHz Radiofrequency Diathermy versus Therapeutic Ultrasound for Pain Relief and Functional Recovery in Patients with Knee Osteoarthritis: A Randomized Controlled Study.

Knee osteoarthritis (KOA) is a prevalent common cause of disability and pain among adults. Transcutaneous radiofrequency (RF) diathermy and therapeutic ultrasound (US) are commonly employed treatments for addressing musculoskeletal conditions. This study aims to evaluate and compare the clinical effectiveness of transcutaneous 4.4 MHz RF diathermy and therapeutic US therapy in individuals diagnosed with KOA. A total of 108 patients with KOA were randomly assigned to either the RF or US groups. Each participant underwent a series of 10 treatment sessions over four weeks and was evaluated at different time points. The assessments included physical evaluations, vital sign measurements, the Numeric Rating Scale (NRS) for pain, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores, the Lequesne index, gait analysis, the 36-Item Short Form Health Survey (SF-36), and analysis of adverse responses. Both groups showed significant differences in NRS, WOMAC scores, and Lequesne index compared to baseline values at both the 10th treatment session and the one-month follow-up assessment. However, no significant disparities were observed between the two groups at each assessment point. In the gait analysis, following the 10th treatment, the RF group showed significant changes in stride length and stride velocity compared to baseline. Four weeks after the completion of treatment, both groups exhibited significant alterations in stride length and stride velocity when compared to baseline measurements. However, regarding cadence, only the RF group exhibited a significant difference compared to baseline. The findings suggest that transcutaneous 4.4 MHz RF diathermy displays a comparable effectiveness to therapeutic US in reducing pain and enhancing functional capacity among individuals with KOA. Further research endeavors are warranted to advance the efficacy of noninvasive treatments for KOA.

Burst stimulation for refractory angina pectoris - A case report.

BACKGROUND: Refractory angina pectoris (RAP) is a chronic, severe chest pain associated with coronary artery disease that cannot be resolved using optimal medical or surgical approaches. Spinal cord stimulation (SCS) is a suitable treatment option. Conventional waveforms of SCS have shown a potent effect on the tempering of RAP. However, SCS is associated with undesired paresthesia. The new burst SCS waveforms have been reported to have fewer adverse effects. CASE: We reviewed a case in which RAP was successfully treated with burst SCS in a middle-aged male, with a tonic waveform employed for breakthrough pain as needed. CONCLUSIONS: Appropriate use of tonic and burst stimulations according to the symptoms is expected to maximize the effect of relieving chest pain induced by RAP.

Augmented Reality-Assisted Navigation System for Transforaminal Epidural Injection.

Purpose: Multiple studies have attempted to demonstrate the benefits of augmented reality (AR)-assisted navigation systems in surgery. Lumbosacral transforaminal epidural injection is an effective treatment commonly used in patients with radiculopathy due to spinal degenerative pathologies. However, few studies have applied AR-assisted navigation systems to this procedure. The study aimed to investigate the safety and effectiveness of an AR-assisted navigation system for transforaminal epidural injection. Patients and Methods: Through a real-time tracking system and a wireless network to the head-mounted display, computed tomography images of the spine and the path of a spinal needle to the target were visualized on a torso phantom with respiration movements installed. From L1/L2 to L5/S1, needle insertions were performed using an AR-assisted system on the left side of the phantom, and the conventional method was performed on the right side. Results: The procedure duration was approximately three times shorter, and the number of radiographs required was reduced in the experimental group compared to the control group. The distance from the needle tips to the target areas in the plan showed no significant difference between the two groups. (AR group 1.7 ± 2.3mm, control group 3.2 ± 2.8mm, P value 0.067). Conclusion: An AR-assisted navigation system may be used to reduce the time required for spinal interventions and ensure the safety of patients and physicians in view of radiation exposure. Further studies are essential to apply AR-assisted navigation systems to spine interventions.

Virtual reality simulator's effectiveness on the spine procedure education for trainee: a randomized controlled trial.

BACKGROUND: Since the onset of the coronavirus disease 2019 pandemic, virtual simulation has emerged as an alternative to traditional teaching methods as it can be employed within the recently established contact-minimizing guidelines. This prospective education study aimed to develop a virtual reality simulator for a lumbar transforaminal epidural block (LTFEB) and demonstrate its efficacy. METHODS: We developed a virtual reality simulator using patient image data processing, virtual X-ray generation, spatial registration, and virtual reality technology. For a realistic virtual environment, a procedure room, surgical table, C-arm, and monitor were created. Using the virtual C-arm, the X-ray images of the patient's anatomy, the needle, and indicator were obtained in real-time. After the simulation, the trainees could receive feedback by adjusting the visibility of structures such as skin and bones. The training of LTFEB using the simulator was evaluated using 20 inexperienced trainees. The trainees' procedural time, rating score, number of C-arm taken, and overall satisfaction were recorded as primary outcomes. RESULTS: The group using the simulator showed a higher global rating score (P = 0.014), reduced procedural time (P = 0.025), reduced number of C-arm uses (P = 0.001), and higher overall satisfaction score (P = 0.007). CONCLUSIONS: We created an accessible and effective virtual reality simulator that can be used to teach inexperienced trainees LTFEB without radiation exposure. The results of this study indicate that the proposed simulator will prove to be a useful aid for teaching LTFEB.

A Comparison of Anesthetic Quality between Single and Septum-based Double Injection for Ultrasound-Guided Costoclavicular Block: A Randomized Controlled Trial.

BACKGROUND: In a costoclavicular (CC) approach of an ultrasound (US)-guided infraclavicular brachial plexus block (BPB), a septum between the lateral and the medial/posterior cords can result in an incomplete block. We hypothesized that double injections in each compartment between the septum would result in a higher success rate of BPB than a single injection in the center of the CC space. OBJECTIVES: This study was conducted to confirm the superiority of block quality achieved by septum-based double injections (experimental group; group E) over single injection in the center of the CC space (control group; group C). STUDY DESIGN: A randomized, controlled trialSETTING: Department of Anesthesiology and Pain Medicine, Korea University College of Medicine, Anam Hospital. METHODS: Sixty-eight patients who underwent upper extremity surgery randomly received a single (SI group, n = 34) or a septum-based double injection (DI group, n = 34) using the CC approach. Ten milliliters of 2% lidocaine, 10 mL of 0.75% ropivacaine, and 5 mL of normal saline were used for BPB in each group (total 25 mL). Sensory-motor blockade of the ipsilateral median, radial, ulnar, and musculocutaneous nerves was assessed by a blinded observer at 5-minute intervals for 30 minutes immediately after local anesthesia administration. The assessed variables were the success rate, the rate of all 4 nerves blockade, and onset time. RESULTS: Thirty minutes after the block, the success rate was significantly higher in the DI group than in the SI group (64.7% in the SI group vs 91.2% in the DI group, P = 0.009), and the rate of all 4 nerves blockade also significantly increased in the DI group compared to the SI group (44.1% in the SI group vs 91.2% in the DI group, P = 0). The onset time was significantly shortened in the DI group compared with the SI group (26.3 ± 5.6 min in the SI group vs 21.3 ± 6.2 min in the DI group, P = 0.010). LIMITATIONS: We considered that the location of the septum was always between the lateral cord superficially and the medial/posterior cords below it. In some patients in whom the septum was not visible, a superficial lateral cord was injected first, and then deep medial and posterior cords were injected, assuming that the 2 compartments were divided by the septum. CONCLUSIONS: Compared with the SI, the septum-based DI of CC approach increased the success rate and the rate of all 4 nerves blockade and shortened the onset time.

Development of pre-procedure virtual simulation for challenging interventional procedures: an experimental study with clinical application.

Background: Most pain management techniques for challenging procedures are still performed under the guidance of the C-arm fluoroscope although it is sometimes difficult for even experienced clinicians to understand the modified three-dimensional anatomy as a two-dimensional X-ray image. To overcome these difficulties, the development of a virtual simulator may be helpful. Therefore, in this study, the authors developed a virtual simulator and presented its clinical application cases. Methods: We developed a computer program to simulate the actual environment of the procedure. Computed tomography (CT) Digital Imaging and Communications in Medicine (DICOM) data were used for the simulations. Virtual needle placement was simulated at the most appropriate position for a successful block. Using a virtual C-arm, the authors searched for the position of the C-arm at which the needle was visualized as a point. The positional relationships between the anatomy of the patient and the needle were identified. Results: For the simulations, the CT DICOM data of patients who visited the outpatient clinic was used. When the patients revisited the clinic, images similar to the simulated images were obtained by manipulating the C-arm. Transforaminal epidural injection, which was difficult to perform due to severe spinal deformity, and the challenging procedures of the superior hypogastric plexus block and Gasserian ganglion block, were successfully performed with the help of the simulation. Conclusions: We created a pre-procedural virtual simulation and demonstrated its successful application in patients who are expected to undergo challenging procedures.

Comparison of Temperature and Pain Changes between the Drip and Topical Methods of Administering the Transnasal Sphenopalatine Ganglion Block.

The objective of this study was to compare facial temperatures and the visual analogue scale (VAS) between the drip method and the topical method of transnasal sphenopalatine ganglion block (SPGB). The transnasal SPGB is administered to patients with facial or head and neck pain. In the transnasal approach, the drip and topical methods are frequently used. We compared facial temperatures and VAS after transnasal SPGB. Medical records of 74 patients who visited the pain clinic and underwent transnasal SPGB were retrospectively reviewed. A total of 156 transnasal SPGB were performed. The patients were divided into the drip-method and topical-method groups. Facial temperatures were measured in six areas of the right and left forehead, maxilla, and mandible before and 30 min after completion of the transnasal SPGB. Temperatures were compared before and 30 min after SPGB in each group and between the two groups. VAS scores were compared at the same times of SPGB in each group and between the two groups. In the drip-method group, there were significant increases at four areas of the face in temperature changes at 30 min after SPGB. In the topical-method group, there was no significant difference in the temperature changes at 30 min after SPGB. There were statistically significant differences in the facial temperature changes between the two groups in the right forehead (p = 0.001), left forehead (p = 0.015), and right maxillary area (p = 0.046). In herpes zoster, there were statistically significant differences in the VAS scores between before and 30 min after SPGB in both groups (p < 0.001, p = 0.008) and between two groups (p < 0.001). In migraine, there were statistically significant differences in VAS scores between before and 30 min after SPGB in both groups (p < 0.001, p = 0.004) and between two groups (p = 0.014). Transnasal SPGB using two methods showed different temperature changes and VAS scores.

Creation of a three-dimensional printed spine model for training in pain procedures.

OBJECTIVE: Technological developments have made it possible to create simulation models to educate clinicians on surgical techniques and patient preparation. In this study, we created an inexpensive lumbar spine phantom using patient data and analyzed its usefulness in clinical education. METHODS: This randomized comparative study used computed tomography and magnetic resonance imaging data from a single patient to print a three-dimensional (3D) bone framework and create a mold. The printed bones and structures made from the mold were placed in a simulation model that was used to train residents. The residents were divided into two groups: Group L, which received only an audiovisual lecture, and Group P, which received an additional 1 hour of training using the 3D phantom. The performance of both groups was evaluated using pretest and post-test analyses. RESULTS: Both the checklist and global rating scores increased after training in both groups. However, some variables improved significantly only in Group P. The overall satisfaction score was also higher in Group P than in Group L. CONCLUSIONS: We have described a method by which medical doctors can create a spine simulation phantom and have demonstrated its efficiency for procedural education.

Comparison of Postoperative Pain and Adverse Effects between Variable-Rate Feedback Infusion and Conventional Fixed-Rate Basal Infusion Modes of Patient-Controlled Epidural Analgesia following Open Gastrectomy: A Randomized Controlled Trial.

Patient-controlled epidural analgesia is widely used to control postoperative pain following major intra-abdominal surgeries. However, determining the optimal infusion dose that can produce effective analgesia while reducing side effects remains a task to be solved. Postoperative pain and adverse effects between variable-rate feedback infusion (VFIM group, n = 36) and conventional fixed-rate basal infusion (CFIM group, n = 36) of fentanyl/ropivacaine-based patient-controlled epidural analgesia were evaluated. In the CFIM group, the basal infusion rate was fixed (5 mL/h), whereas, in the VFIM group, the basal infusion rate was increased by 0.5 mL/h each time a bolus dose was administered and decreased by 0.3 mL/h when a bolus dose was not administered for 2 h. Patients in the VFIM group experienced significantly less pain at one to six hours after surgery than those in the CFIM group. Further, the number of patients who suffered from postoperative nausea was significantly lower in the VFIM group than in the CFIM group until six hours after surgery. The variable-rate feedback infusion mode of patient-controlled epidural analgesia may provide better analgesia accompanied with significantly less nausea in the early postoperative period than the conventional fixed-rate basal infusion mode following open gastrectomy.

Successful application of burst spinal cord stimulation for refractory upper limb pain: a case series.

Spinal cord stimulation (SCS) has been used to treat sustained pain that is intractable despite various types of treatment. However, conventional tonic waveform SCS has not shown promising outcomes for spinal cord injury (SCI) or postamputation pain. The pain signal mechanisms of burst waveforms are different to those of conventional tonic waveforms, but few reports have presented the therapeutic potential of burst waveforms for the abovementioned indications. This current case report describes two patients with refractory upper limb pain after SCI and upper limb amputation that were treated with burst waveform SCS. While the patients could not obtain sufficient therapeutic effect with conventional tonic waveforms, the burst waveforms provided better pain reduction with less discomfort. However, further studies are necessary to better clarify the mechanisms and efficacy of burst waveform SCS in patients with intractable pain.

An anatomical neurovascular study for procedures targeting peri-articular nerves in patients with anterior knee pain.

BACKGROUND: Radiofrequency ablation (RFA) of the articular branches innervating the anterior knee capsule has been studied as a possible alternative to surgery for degenerative arthritis. However, the neurovascular topography of the anterior knee capsule remains unclear. METHODS: One leg from each of the 20 formalin-embalmed cadaveric specimens was investigated. Modified ablation points (MAPs) were evaluated for a possible alternative for conventional target points (CAPs). RESULTS: For the nerve to vastus medialis (NVM), the probability of identifying the nerve was higher at MAP compared with CAP (62.5% vs. 25%). The mean shortest distance from the nerve was shorter at MAP compared with CAP (18.0 mm vs. 29.9 mm). The probabilities and distances for other nerves were not significantly different between the points. However, the probability of identifying the artery was significantly lower at MAPs compared with CAPs for arteries (0%, 5.3%, and 0% vs. 84.2%, 84.2%, and 73.3% for superior medial genicular, superior lateral genicular, and inferior medial genicular artery, respectively). For the recurrent peroneal nerve (RPN), a new target point was set in MAPs. CONCLUSIONS: The current landmark for genicular nerve procedures may not accurately target the correct nerve position, or reduce the risk for vessel damage. A more proximal target may reduce complications and increase the probability of successful procedures, although clinical correlation is needed.

Application of purified porcine collagen in patients with chronic refractory musculoskeletal pain.

BACKGROUND: This study aimed to assess the potential efficacy of purified porcine atelocollagen (PAC) for the management of refractory chronic pain due to suspected connective tissue damage. METHODS: Patients treated with PAC were retrospectively evaluated. Patients with chronic refractory pain, suspected to have originated from musculoskeletal damage or defects with the evidence of imaging studies were included. Pain intensity, using the 11-point numerical rating scale (NRS), was assessed before the procedure, and 1 month after the last procedure. RESULTS: Eighty-eight patients were finally included for investigation. The mean NRS score was decreased from 5.8 to 4.1 after 1 month of PAC injection (P < 0.001). No independent factor was reported to be directly related to the decrease in NRS score by more than half. CONCLUSIONS: Application of PAC may have potential as a treatment option for refractory chronic musculoskeletal pain. PAC might promote tissue recovery, act as a scaffold for repair, or directly reduce inflammation.

Comparison of Analgesic and Adverse Effects of Oxycodone- and Fentanyl-Based Patient-Controlled Analgesia in Patients Undergoing Robot-Assisted Laparoscopic Gastrectomy Using a 55:1 Potency Ratio of Oxycodone to Fentanyl: A Retrospective Study.

PURPOSE: Oxycodone has affinities for both kappa- and mu-opioid receptors. Therefore, it has been used for postoperative analgesia of surgeries in which visceral pain is expected to be the main cause of pain. However, there are few studies of the 55:1 potency ratio of oxycodone to fentanyl when using it as intravenous patient-controlled analgesia (IV-PCA). Thus, we compared the analgesic and adverse effects of IV-PCA using the 55:1 potency ratio of oxycodone to fentanyl in patients who underwent robot-assisted laparoscopic gastrectomy. PATIENTS AND METHODS: This retrospective study included 100 patients using an automatic PCA pump with oxycodone or fentanyl who underwent robot-assisted laparoscopic gastrectomy between January and November 2017. All patients were provided with an IV-PCA consisting of 20 µg/kg of fentanyl or 1.1 mg/kg of oxycodone mixed with 0.9% normal saline solution to a total volume of 250 mL, which was infused basally at a rate of 0.1 mL/h with a bolus dose of 1 mL and lockout time of 6 min. The primary and secondary endpoints were to evaluate the efficacies of IV-PCA using the 55:1 potency ratio of oxycodone to fentanyl on analgesic and adverse effects. RESULTS: Pain intensity on arrival at the post-anesthesia care unit (PACU; 3.6±1.4 vs 4.4±2.0, P=0.031) and additional analgesic requirement within an hour after surgery (including the PACU period) (12% vs 37%; P=0.005) were significantly lower in the oxycodone group (n=49) than in the fentanyl group (n=51). Regarding adverse effects, the rate of postoperative nausea within 1 h after surgery (2% vs 16%; P=0.031) was also significantly lower in the oxycodone group than that in the fentanyl group. CONCLUSION: Oxycodone-based IV-PCA by dose calculations with a 55:1 potency ratio may achieve better analgesia without any significant adverse effects, when using IV-PCA in patients undergoing robot-assisted laparoscopic gastrectomy.

A Novel Application of Buprenorphine Transdermal Patch to Relieve Pain in the Knee Joint of Knee Osteoarthritis Patients: A Retrospective Case-Control Study.

Osteoarthritis (OA) is considered to be one of the most disabling diseases. The intra-articular opioid injection has been widely studied for its simplicity, safety, and efficacy in OA. In this study, however, we suggest a novel method of buprenorphine transdermal patch (BTDP) to painful knee joints of OA patients, instead of intra-articular opioid injection, and subsequently compared the knee application with conventional chest application. We retrospectively enrolled 213 patients with knee OA who did not respond to conventional therapy. The Numeric Rating Scale (NRS), adverse effects, and compliance were recorded before and after the application of the BTDP. All parameters were compared between the knee applied group and the chest applied group. After the BTDP application, the NRS score in the knee applied group was lower than that of the chest applied group (p = 0.007). NRS scores after buprenorphine patch decreased to 2.21 ± 0.77, and 2.55 ± 0.71 in the chest applied group and the knee applied group, respectively. The adverse effects were 19.32% in the knee applied group, and 64.00% in the chest applied group. The compliances were 82.95% and 37.60% in the knee applied group and chest applied group, respectively. This novel application of BTDP directly to the painful knee joint of knee OA patients led to a decrease in the NRS score, adverse effects, and an increase in compliance compared with the chest application method.

Influence of reversal of neuromuscular blockade with sugammadex or neostigmine on postoperative quality of recovery following a single bolus dose of rocuronium: A prospective, randomized, double-blinded, controlled study.

STUDY OBJECTIVE: To evaluate the influence of reversal of neuromuscular blockade with sugammadex or neostigmine on postoperative quality of recovery following a single bolus dose of rocuronium after pars plana vitrectomy (PPV) under general anesthesia. DESIGN: Prospective, double-blind, randomized controlled trial. SETTING: This study was conducted in a University Teaching Hospital from February to July 2017. PATIENTS: A total of 84 patients with an American Society of Anesthesiologists physical status of I or II who were scheduled to undergo PPV under general anesthesia. INTERVENTIONS: The patients were randomly assigned to the neostigmine (Group N, n = 44) or sugammadex (Group S, n = 40) groups; 3 ml of study drug was prepared for the patients. For patients in Group N, a solution of neostigmine methylsulfate (1 mg) and glycopyrrolate (0.2 mg) was prepared, while a solution of sugammadex sodium (2 mg/kg) and normal saline was prepared for patients in Group S. MEASUREMENTS: The primary endpoint was the effect of sugammadex, compared with neostigmine, on the recovery rate in the physiological domain in patients who underwent PPV with general anesthesia. The quality of recovery was assessed using the Postoperative Quality Recovery Scale at 15 min and 40 min after surgery, and on postoperative day 1. MAIN RESULTS: The recovery rate in the physiological domain was higher in Group S at 15 min after surgery (P = 0.020). Though there were no significant differences in the overall cognitive recovery domain, patients in Group S could recall more numbers in reverse order. However, there were no significant differences between the groups in the other domains of the scale. CONCLUSIONS: The use of sugammadex may increase the quality of physiological recovery at early postoperative periods, compared with that of neostigmine, following a single bolus dose of rocuronium in patients undergoing PPV with general anesthesia. TRIAL REGISTRATION: Registered at ClinicalTrials.gov (https://clinicaltrials.gov/ct2/show/NCT03108989). Registration number: NCT03108989.

Effects of long periods of pneumoperitoneum combined with the head-up position on heart rate-corrected QT interval during robotic gastrectomy: an observational study.

OBJECTIVE: Pneumoperitoneum and the head-up position reportedly stimulate the sympathetic nervous system, potentially increasing the risk of cardiac arrhythmia. We evaluated the effects of a long duration of pneumoperitoneum in the head-up position on the heart rate-corrected QT (QTc) interval during robotic gastrectomy. METHODS: This prospective observational study involved 28 patients undergoing robotic gastrectomy. The QTc interval was recorded at the following time points: before anaesthetic induction (baseline); 10 minutes after tracheal intubation; 1, 5, 30, 60, and 90 minutes after pneumoperitoneum induction in the head-up position; after pneumoperitoneum desufflation in the supine position; and at the end of surgery. The primary outcome was the QTc interval, which was measured 90 minutes after pneumoperitoneum combined with the head-up position. RESULTS: Compared with baseline, the QTc interval was significantly prolonged at 1 and 60 minutes after pneumoperitoneum, peaked at 90 minutes, and was sustained and notably prolonged until the end of surgery. However, no considerable haemodynamic changes developed. CONCLUSION: A long period of carbon dioxide pneumoperitoneum application in a head-up position significantly prolonged the QTc interval during robotic gastrectomy. Therefore, diligent care and close monitoring are required for patients who are susceptible to developing ventricular arrhythmia. Trial Registration: Registered at ClinicalTrials.gov; https://clinicaltrials.gov/ct2/show/NCT02604979 ; Registration number NCT02604979.

Effects of remifentanil with or without midazolam pretreatment on the 95% effective dose of propofol for loss of consciousness during induction: A randomized, clinical trial.

BACKGROUND: Propofol is a rapid, efficient hypnotic agent with antiemetic effects. However, a high dosage is related to hemodynamic abnormalities such as hypotension and bradycardia. Pretreatment with remifentanil can decrease injection pain and stabilize hemodynamics during the induction period. Remifentanil or midazolam in combination with propofol can provide synergistic or additive effects during anesthesia induction. However, the hypnotic doses of propofol required in patients who receive pretreatment with remifentanil or midazolam remain unclear. METHODS: Patients aged 20 to 50 years who were scheduled to undergo surgery under general anesthesia were enrolled in this study. The patients were randomized into 3 groups using a computer-generated randomization table. Patients in Group P (Propofol) received only propofol for loss of consciousness, those in Group PR (Propofol-Remifentanil) received remifentanil prior to propofol, and those in Group PMR (Propofol-Midazolam-Remifentanil) received remifentanil and midazolam prior to propofol. After propofol administration, loss of both the eyelash reflex and verbal response represented success. The 95% effective dose of propofol for loss of consciousness in each group, which was the primary outcome, was determined using a modified biased coin up-and-down method. RESULTS: A total of 124 patients were initially enrolled. Of these, 4 were excluded, and the remaining 120 patients were randomized to each (n = 40) of the 3 groups. The 95% effective dose of propofol for loss of consciousness was 1.74 , 1.38, and 0.92 mg/kg in Groups P, PR, and PMR, respectively. Blood pressure decreased at 2 minutes after propofol administration in all the groups. However, compared with Group P, Groups PR and PMR exhibited a significant decrease in blood pressure. CONCLUSIONS: The effective dose of propofol for loss of consciousness could be decreased by 21% and 47% when remifentanil pretreatment was used without and with midazolam, respectively. However, the decrease in blood pressure was greater with pretreatment than sole propofol use. These findings suggest that the combination of remifentanil with or without midazolam may have no benefit on hemodynamic stability during induction using propofol. TRIAL REGISTRATION: NCT02536690 (clinicaltrials.gov).