Background Most depth of anesthesia (DOA) monitors rely on the temporal characteristics of a single-channel electroencephalogram (EEG) and cannot provide spatial or connectivity information. Phase lag entropy (PLE) reflects DOA by calculating diverse connectivity from temporal patterns of phase relationships. The aim of this study was to compare the performance of PLE and bispectral index (BIS) monitors for assessing DOA during anesthesia induction, nerve integrity monitoring (NIM), and anesthesia emergence. Methods Thirty-five patients undergoing elective thyroid surgery with recurrent laryngeal nerve NIM received propofol and remifentanil via target-controlled infusion. After applying PLE and BIS monitors, propofol infusion was initiated at a calculated effect site concentration (Ce) of 2 µg/mL and then increased in 1-µg/mL Ce increments. After propofol Ce reached 5 μg/mL, a remifentanil infusion was begun, and anesthesia induction was considered complete. During NIM, PLE and BIS values were compared at a specific time points from platysma muscle exposure to subcutaneous tissue closure. PLE and BIS values were recorded continuously from preanesthetic state to full recovery of orientation; bias and limits of agreement between monitors were calculated. Results PLE and BIS values decreased progressively with increasing propofol Ce during anesthetic induction and increased by stages during emergence. The prediction probabilities of PLE and BIS for detecting propofol Ce changes were 0.750 and 0.756, respectively, during induction and 0.749 and 0.746, respectively, during emergence. No aberrant PLE or BIS values occurred during NIM. Correlation coefficients for BIS and PLE were 0.98 and 0.92 during induction and emergence, respectively. PLE values were significantly higher than BIS values at full recovery of orientation. Estimated bias between monitors was −4.16 ± 8.7, and 95% limits of agreement were −21.21 to 12.89. Conclusion PLE is a reasonable alternative to BIS for evaluating consciousness and DOA during general anesthesia and during NIM. Trial Registration Clinical Research Information Service Identifier: KCT0003490

Background: Immobilization with cervical spine worsens endotracheal intubation condition. Though various intubation devices have been demonstrated to perform well in oral endotracheal intubation, limited information is available concerning nasotracheal intubation (NTI) in patients with cervical spine immobilization. The present study compared the performance of the C-MAC D-Blade videolaryngoscope with the McCoy laryngoscope for NTI in patients with simulated cervical spine injuries. Methods: This was a prospective, randomized, controlled, study done in a tertiary hospital. Ninety-five patients requiring NTI were included in data analysis: McCoy group (group M, n = 47) or C-MAC D-Blade videolaryngoscope group (group C, n = 48). A Philadelphia neck collar was applied before anesthetic induction to immobilize the cervical spine. Single experienced anesthesiologist performed NTI. The primary outcome was duration of intubation divided by three steps: nose to oropharynx; oropharynx into glottic inlet; and glottic inlet to trachea. Secondary outcomes included glottic view as percentage of glottis opening (POGO) score and Cormack-Lehance (CL) grade, modified nasal intubation-difficulty scale (NIDS) rating, hemodynamic changes before and after intubation, and complications.Results: Total intubation duration was significantly shorter in group C (39.5 ± 11.4 s) compared to group M (48.1 ± 13.9 s). Group C required significantly less time for glottic visualization and endotracheal tube placement in the trachea. More patients in group C had CL grade I and higher POGO scores (P < 0.001, for both measures). No difficulty in NTI (modified NIDS = 0) was more in group C than group M. Hemodynamic changes and incidence of complications were comparable between groups.(Continued on next page)

Background: Optimal needle depth in transforaminal epidural injection (TFEI) is determined by body measurements and is influenced by the needle entry angle. Physician can choose the appropriate needle length and perform the procedure more effectively if depth is predicted in advance. Methods: This retrospective study included patients with lumbosacral pain from a single university hospital. The skin depth from the target point was measured using magnetic resonance imaging transverse images. The depth was measured bilaterally for L4 and L5 TFEIs at 15°, 20°, and 25° oblique angles from the spinous process. Results: A total of 4,632 measurements of 386 patients were included. The lengths of the left and right TFEI at the same level and oblique angle were assessed, and no statistical differences were identified. Therefore, linear regression analysis was performed for bilateral L4 and L5 TFEIs. The R-squared values of height and weight combined were higher than the height, weight, and body mass index (BMI). The following equation was established: Depth (mm) = a -b (height, cm) + c (weight, kg). Based on the equation, maximal BMI capable with a 23G, 3.5-inch, Quincke-type point spinal needle was presented for three different angles (15°, 20°, and 25°) at lumbar levels L4 and L5. Conclusions: The maximal BMI that derived from the formulated equation is listed on the table, which can help in preparations for morbid obesity. If a patient has bigger BMI than the one in the table, the clinician should prepare longer needle than the usual spinal needle.

Background The coronavirus disease 2019 (COVID-19) pandemic has caused significant changes. This study aimed to investigate the impact of COVID-19 on patients with chronic pain. Methods Patients with chronic pain from 23 university hospitals in South Korea participated in this study. The anonymous survey questionnaire consisted of 25 questions regarding the following demographic data, diagnosis, hospital visit frequency, exercise duration, time outside, sleep duration, weight change, nervousness and anxiety, depression, interest or pleasure, fatigue, daily life difficulties, and self-harm thoughts. Depression severity was evaluated using the Patient Health Questionnaire-9 (PHQ-9). Logistic regression analysis was used to investigate the relationship between increased pain and patient factors. Results A total of 914 patients completed the survey, 35.9% of whom had decreased their number of visits to the hospital, mostly due to COVID-19. The pain level of 200 patients has worsened since the COVID-19 outbreak, which was more prominent in complex regional pain syndrome (CRPS). Noticeable post-COVID-19 changes such as exercise duration, time spent outside, sleep patterns, mood, and weight affected patients with chronic pain. Depression severity was more significant in patients with CRPS. The total PHQ-9 average score of patients with CRPS was 15.5, corresponding to major depressive orders. The patients’ decreased exercise duration, decreased sleep duration, and increased depression were significantly associated with increased pain. Conclusions COVID-19 has caused several changes in patients with chronic pain. During the pandemic, decreased exercise and sleep duration and increased depression were associated with patients’ increasing pain.

Background: Inserting a double-lumen endotracheal tube (DLT) poses more challenge than inserting a single-lumen tube. The C-MAC D-blade videolaryngoscope is a useful alternative to the direct laryngoscope. However, no study has compared its performance with that of the McCoy laryngoscope, which has a hyperangulated blade tip similar to that of the C-MAC D-blade. We aimed to compare the performance of the C-MAC D-blade videolaryngoscope with that of the McCoy laryngoscope in DLT intubation.Methods: In this prospective randomized controlled study, 90 patients requiring DLT intubation were randomly allocated to either the C-MAC D-blade videolaryngoscope group (group C, n = 47) or McCoy laryngoscope group (group M, n = 43). During intubation, the percentage of glottic opening, modified Cormack-Lehane grade, time taken for intubation, malposition of the bronchial lumen, and hemodynamic parameters were recorded. After intubation, we assessed the intubation difficulty scale score and, a postoperative sore throat in the recovery room.Results: The time taken for intubation was 35.85 ± 10.77 seconds and 33.18 ± 11.97 seconds in groups C and M, respectively (P = .269). The modified Cormack-Lehane grade was significantly lower in group C than in group M (P = .000). Percentage of glottic opening was significantly higher in group C (79.36 ± 13.42%) than in group M (53.49 ± 29.83%) (P = .000). The intubation difficulty scale score was significantly lower in group C than in group M (P = .030). There were no significant differences between the 2 groups in terms of malposition status, hemodynamic parameters, or visual analog scale score for a postoperative sore throat. Conclusion:Although the time taken for intubation was comparable between the 2 intubation devices, the C-MAC D-blade videolaryngoscope facilitated glottis visualization and reduced the intubation difficulty scale better than the McCoy laryngoscope in patients undergoing DLT intubation.Abbreviations: BURP = backward, upward, and rightward pressure maneuvers, DLT = double-lumen endobronchial tube, Fr = French, HR = heart rate, IDS = intubation difficulty scale, MAP = mean arterial pressure, POGO = percentage of glottic opening, SPI = surgical pleth index, SpO 2 = peripheral oxygen saturation, T0 = baseline, T1 = immediately before intubation, T2 = immediately after intubation, T3 = 3 minutes after intubation, VAS = visual analog scale.