Although preoxygenation is an essential procedure for safe endotracheal intubation, in some cases securing sufficient time for tracheal intubation may not be possible. Patients with head and neck cancer might have a difficult airway and need a longer time for endotracheal intubation. We hypothesized that the extended apneic period with preoxygenation via a high-flow nasal cannula (HFNC) is beneficial to patients who undergo head and neck surgery compared with preoxygenation with a simple mask. Methods: The study was conducted as a single-center, single-blinded, prospective, randomized controlled trial. Patients were divided into groups based on one of the two preoxygenation methods: HFNC group or simple facemask (mask group). Preoxygenation was performed for 5 minutes with each method, and endotracheal intubation for all patients was performed using a video laryngoscope. Oxygen partial pressures of the arterial blood were compared at the predefined time points. Results: For the primary outcome, the mean arterial oxygen partial pressure (PaO2 ) immediately after intubation was 454.2 mm Hg (95% confidence interval [CI], 416.9–491.5 mm Hg) in the HFNC group and 370.7 mm Hg (95% CI, 333.7–407.4 mm Hg) in the mask group (P=0.002). The peak PaO2 at 5 minutes after preoxygenation was not statistically different between the groups (P=0.355). Conclusions: Preoxygenation with a HFNC extending to the apneic period before endotracheal intubation may be beneficial in patients with head and neck cancer.

Although preoxygenation is an essential procedure for safe endotracheal intubation, in some cases securing sufficient time for tracheal intubation may not be possible. Patients with head and neck cancer might have a difficult airway and need a longer time for endotracheal intubation. We hypothesized that the extended apneic period with preoxygenation via a high-flow nasal cannula (HFNC) is beneficial to patients who undergo head and neck surgery compared with preoxygenation with a simple mask. Methods: The study was conducted as a single-center, single-blinded, prospective, randomized controlled trial. Patients were divided into groups based on one of the two preoxygenation methods: HFNC group or simple facemask (mask group). Preoxygenation was performed for 5 minutes with each method, and endotracheal intubation for all patients was performed using a video laryngoscope. Oxygen partial pressures of the arterial blood were compared at the predefined time points. Results: For the primary outcome, the mean arterial oxygen partial pressure (PaO2 ) immediately after intubation was 454.2 mm Hg (95% confidence interval [CI], 416.9–491.5 mm Hg) in the HFNC group and 370.7 mm Hg (95% CI, 333.7–407.4 mm Hg) in the mask group (P=0.002). The peak PaO2 at 5 minutes after preoxygenation was not statistically different between the groups (P=0.355). Conclusions: Preoxygenation with a HFNC extending to the apneic period before endotracheal intubation may be beneficial in patients with head and neck cancer.

Although preoxygenation is an essential procedure for safe endotracheal intubation, in some cases securing sufficient time for tracheal intubation may not be possible. Patients with head and neck cancer might have a difficult airway and need a longer time for endotracheal intubation. We hypothesized that the extended apneic period with preoxygenation via a high-flow nasal cannula (HFNC) is beneficial to patients who undergo head and neck surgery compared with preoxygenation with a simple mask. Methods: The study was conducted as a single-center, single-blinded, prospective, randomized controlled trial. Patients were divided into groups based on one of the two preoxygenation methods: HFNC group or simple facemask (mask group). Preoxygenation was performed for 5 minutes with each method, and endotracheal intubation for all patients was performed using a video laryngoscope. Oxygen partial pressures of the arterial blood were compared at the predefined time points. Results: For the primary outcome, the mean arterial oxygen partial pressure (PaO2 ) immediately after intubation was 454.2 mm Hg (95% confidence interval [CI], 416.9–491.5 mm Hg) in the HFNC group and 370.7 mm Hg (95% CI, 333.7–407.4 mm Hg) in the mask group (P=0.002). The peak PaO2 at 5 minutes after preoxygenation was not statistically different between the groups (P=0.355). Conclusions: Preoxygenation with a HFNC extending to the apneic period before endotracheal intubation may be beneficial in patients with head and neck cancer.

Although preoxygenation is an essential procedure for safe endotracheal intubation, in some cases securing sufficient time for tracheal intubation may not be possible. Patients with head and neck cancer might have a difficult airway and need a longer time for endotracheal intubation. We hypothesized that the extended apneic period with preoxygenation via a high-flow nasal cannula (HFNC) is beneficial to patients who undergo head and neck surgery compared with preoxygenation with a simple mask. Methods: The study was conducted as a single-center, single-blinded, prospective, randomized controlled trial. Patients were divided into groups based on one of the two preoxygenation methods: HFNC group or simple facemask (mask group). Preoxygenation was performed for 5 minutes with each method, and endotracheal intubation for all patients was performed using a video laryngoscope. Oxygen partial pressures of the arterial blood were compared at the predefined time points. Results: For the primary outcome, the mean arterial oxygen partial pressure (PaO2 ) immediately after intubation was 454.2 mm Hg (95% confidence interval [CI], 416.9–491.5 mm Hg) in the HFNC group and 370.7 mm Hg (95% CI, 333.7–407.4 mm Hg) in the mask group (P=0.002). The peak PaO2 at 5 minutes after preoxygenation was not statistically different between the groups (P=0.355). Conclusions: Preoxygenation with a HFNC extending to the apneic period before endotracheal intubation may be beneficial in patients with head and neck cancer.

Purpose: In men with metastatic castration-resistant prostate cancer (mCRPC), new bone lesions are sometimes not properly categorized through a confirmatory bone scan, and clinical significance of the test itself remains unclear. This study aimed to demonstrate the performance rate of confirmatory bone scans in a real-world setting and their prognostic impact in enzalutamide-treated mCRPC. Materials and Methods: Patients who received oral enzalutamide for mCRPC during 2014-2017 at 14 tertiary centers in Korea were included. Patients lacking imaging assessment data or insufficient drug exposure were excluded. The primary outcome was overall survival (OS). Secondary outcomes included performance rate of confirmatory bone scans in a real-world setting. Kaplan-Meier analysis and multivariate Cox regression analysis were performed. Results: Overall, 520 patients with mCRPC were enrolled (240 [26.2%] chemotherapy-naïve and 280 [53.2%] after chemotherapy). Among 352 responders, 92 patients (26.1%) showed new bone lesions in their early bone scan. Confirmatory bone scan was performed in 41 patients (44.6%), and it was associated with prolonged OS in the entire population (median, 30.9 vs. 19.7 months; p < 0.001), as well as in the chemotherapy-naïve (median, 47.2 vs. 20.5 months; p=0.011) and post-chemotherapy sub-groups (median, 25.5 vs. 18.0 months; p=0.006). Multivariate Cox regression showed that confirmatory bone scan performance was an independent prognostic factor for OS (hazard ratio 0.35, 95% confidence interval, 0.18 to 0.69; p=0.002). Conclusion Confirmatory bone scan performance was associated with prolonged OS. Thus, the premature discontinuation of enzalutamide without confirmatory bone scans should be discouraged.

Endoscopic ultrasound (EUS)-guided interventions have evolved rapidly in recent years, with dedicated metal stents playing a crucial role in this process. Specifically, the invention of biflanged short metal-covered stents, including lumen-apposing metal stents (LAMS), and modifications in a variety of tubular self-expandable metal stents (SEMS), have led to innovations in EUS-guided interventions. LAMS or non-LAMS stents are commonly used in the EUS-guided drainage of pancreatic fluid collections, especially in cases of walled-off necrosis. Additionally, LAMS is commonly considered for drainage of the EUS-guided gallbladder or dilated common bile duct and EUS-guided gastroenterostomy. Fully or partially covered tubular SEMS with several new designs are being considered for EUS-guided biliary drainage. This review focuses on advances in SEMS for EUS-guided interventions and discusses related research results.

Background: In patients with metastatic renal cell carcinoma (mRCC), sites of metastatic involvement have been reported to be associated with a difference in survival. However, the frequency and survival according to different sites of metastases in Korean patients with mRCC remain unclear. Therefore, this study aimed to assess the frequency of metastatic site involvement and the association between sites of metastatic involvement and survival in Korean patients with mRCC. Methods: This retrospective study used the multicenter cohort of the Korean Renal Cancer Study Group mRCC database to identify patients who started targeted therapy between December 2005 and March 2018. Data on the frequency of metastatic organ involvement at the time of mRCC diagnosis and oncologic outcomes according to different sites of metastasis were analyzed. Results: A total of 1,761 patients were eligible for analysis. Of the 1,761 patients, 1,564 (88.8%) had clear cell RCC, and 1,040 (59.1%) had synchronous metastasis. The median number of metastasis sites was 2 (interquartile range [IQR], 1–6). The median age at the initiation of systemic therapy was 60 years (IQR, 29–88), 1,380 (78.4%) were men, and 1,341 (76.1%) underwent nephrectomy. Based on the International Metastatic Renal Cell Carcinoma Database Consortium model, patients were stratified into favorable-, intermediate-, and poor-risk groups with 359 (20.4%), 1,092 (62.0%), and 310 (17.6%) patients, respectively. The lung (70.9%), lymph nodes (37.9%), bone (30.7%), liver (12.7%), adrenal gland (9.8%), and brain (8.2%) were the most common sites of metastasis, followed by the pancreas, pleura, peritoneum, spleen, thyroid, and bowel. Among the most common sites of metastasis (> 5%), the median cancer-specific survival (CSS) ranged from 13.9 (liver) to 29.1 months (lung). An association was observed between liver, bone, and pleural metastases and the shortest median CSS (< 19 months). Conclusion In Korean patients with mRCC, metastases to the lung, lymph nodes, bone, liver, adrenal gland, and brain were more frequent than those to other organs. Metastases to the liver, bone, and pleura were associated with poor CSS. The findings of this study may be valuable for patient counseling and guiding future study designs.

Purpose: The diagnosis and management of cardiovascular diseases are important for pilots, as well as the assessment of workload. Heart rate variability (HRV) can be evaluated from electrocardiography (ECG) signals during flight phases to assess the activation of the autonomic nervous system. Methods: In this study, continuous ECG activity was recorded of one pilot who flied as a pilot flying during a 4-hour long round trip using wearable ECG machine and was analyzed with MATLAB (R2020b ver. 9.9, The Mathworks Inc.). Total flight was divided into five phases: preflight, take off, cruise, landing, and postflight. Results: Mean heart rate (HR) was lowest in the postflight phase (76 bpm), and highest in the landing phase (86 bpm). Landing phase showed the highest values in standard deviation of NN interval (59.3 ms), triangular index (11.7), and triangular interpolation of NN interval (195 ms), while the postflight phase had highest root mean square of successive difference (20.5 ms) and proportion of successive RR interval (3.4 ms). As for frequency-domain metrics, the landing phase had the highest lowfrequency/high-frequency ratio of 5.33. Among the non-linear HRV measures, the landing phase presented the lowest SD1/SD2 ratio (0.15). Conclusion We observed the relative increase of mean HR and change of HRV in the landing phase, indicating elevated sympathetic nervous tone. Further studies should be considered to evaluate specific changes of ECG signals in flight phases and confirm the clinical use of the MATLAB signal analysis tools.

Background: In patients with metastatic renal cell carcinoma (mRCC), sites of metastatic involvement have been reported to be associated with a difference in survival. However, the frequency and survival according to different sites of metastases in Korean patients with mRCC remain unclear. Therefore, this study aimed to assess the frequency of metastatic site involvement and the association between sites of metastatic involvement and survival in Korean patients with mRCC. Methods: This retrospective study used the multicenter cohort of the Korean Renal Cancer Study Group mRCC database to identify patients who started targeted therapy between December 2005 and March 2018. Data on the frequency of metastatic organ involvement at the time of mRCC diagnosis and oncologic outcomes according to different sites of metastasis were analyzed. Results: A total of 1,761 patients were eligible for analysis. Of the 1,761 patients, 1,564 (88.8%) had clear cell RCC, and 1,040 (59.1%) had synchronous metastasis. The median number of metastasis sites was 2 (interquartile range [IQR], 1–6). The median age at the initiation of systemic therapy was 60 years (IQR, 29–88), 1,380 (78.4%) were men, and 1,341 (76.1%) underwent nephrectomy. Based on the International Metastatic Renal Cell Carcinoma Database Consortium model, patients were stratified into favorable-, intermediate-, and poor-risk groups with 359 (20.4%), 1,092 (62.0%), and 310 (17.6%) patients, respectively. The lung (70.9%), lymph nodes (37.9%), bone (30.7%), liver (12.7%), adrenal gland (9.8%), and brain (8.2%) were the most common sites of metastasis, followed by the pancreas, pleura, peritoneum, spleen, thyroid, and bowel. Among the most common sites of metastasis (> 5%), the median cancer-specific survival (CSS) ranged from 13.9 (liver) to 29.1 months (lung). An association was observed between liver, bone, and pleural metastases and the shortest median CSS (< 19 months). Conclusion In Korean patients with mRCC, metastases to the lung, lymph nodes, bone, liver, adrenal gland, and brain were more frequent than those to other organs. Metastases to the liver, bone, and pleura were associated with poor CSS. The findings of this study may be valuable for patient counseling and guiding future study designs.

Purpose: The diagnosis and management of cardiovascular diseases are important for pilots, as well as the assessment of workload. Heart rate variability (HRV) can be evaluated from electrocardiography (ECG) signals during flight phases to assess the activation of the autonomic nervous system. Methods: In this study, continuous ECG activity was recorded of one pilot who flied as a pilot flying during a 4-hour long round trip using wearable ECG machine and was analyzed with MATLAB (R2020b ver. 9.9, The Mathworks Inc.). Total flight was divided into five phases: preflight, take off, cruise, landing, and postflight. Results: Mean heart rate (HR) was lowest in the postflight phase (76 bpm), and highest in the landing phase (86 bpm). Landing phase showed the highest values in standard deviation of NN interval (59.3 ms), triangular index (11.7), and triangular interpolation of NN interval (195 ms), while the postflight phase had highest root mean square of successive difference (20.5 ms) and proportion of successive RR interval (3.4 ms). As for frequency-domain metrics, the landing phase had the highest lowfrequency/high-frequency ratio of 5.33. Among the non-linear HRV measures, the landing phase presented the lowest SD1/SD2 ratio (0.15). Conclusion We observed the relative increase of mean HR and change of HRV in the landing phase, indicating elevated sympathetic nervous tone. Further studies should be considered to evaluate specific changes of ECG signals in flight phases and confirm the clinical use of the MATLAB signal analysis tools.