A Hybrid Kinematic-Acoustic System for Automated Activity Detection of Construction Equipment.

Automatically recognizing and tracking construction equipment activities is the first step towards performance monitoring of a job site. Recognizing equipment activities helps construction managers to detect the equipment downtime/idle time in a real-time framework, estimate the productivity rate of each equipment based on its progress, and efficiently evaluate the cycle time of each activity. Thus, it leads to project cost reduction and time schedule improvement. Previous studies on this topic have been based on single sources of data (e.g., kinematic, audio, video signals) for automated activity-detection purposes. However, relying on only one source of data is not appropriate, as the selected data source may not be applicable under certain conditions and fails to provide accurate results. To tackle this issue, the authors propose a hybrid system for recognizing multiple activities of construction equipment. The system integrates two major sources of data-audio and kinematic-through implementing a robust data fusion procedure. The presented system includes recording audio and kinematic signals, preprocessing data, extracting several features, as well as dimension reduction, feature fusion, equipment activity classification using Support Vector Machines (SVM), and smoothing labels. The proposed system was implemented in several case studies (i.e., ten different types and equipment models operating at various construction job sites) and the results indicate that a hybrid system is capable of providing up to 20% more accurate results, compared to cases using individual sources of data.

Influence of intraoperative sevoflurane or desflurane on postoperative sore throat: a prospective randomized study.

PURPOSE: Tracheal intubation for general anesthesia causes postoperative sore throat. The purpose of this study was to evaluate the effect of sevoflurane and desflurane on prevalence of postoperative sore throat in patients after general anesthesia. METHODS: Ninety-six patients scheduled for orthopedic lower extremity surgery under general anesthesia were assigned to sevoflurane group or desflurane group. In the sevoflurane group (n = 48), sevoflurane was used as a maintenance anesthetic agent. In the desflurane group (n = 48), desflurane was used. Prevalence of sore throat, number of patients with rescue analgesics, and analgesics requirements were evaluated. RESULTS: The overall prevalence of postoperative sore throat in the sevoflurane group was lower than that in the desflurane group [21 (44%) vs. 32 (67%), p = 0.024]. The prevalence of sore throat at postoperative 4 h in the sevoflurane group was lower than that in the desflurane group [6 (13%) vs. 18 (38%), p = 0.005]. The number of patients requiring rescue analgesics was lower in the sevoflurane group [25 (52%) vs. 36 (75%), p = 0.020]. The requirement of diclofenac was also lower in the sevoflurane group (30 ± 37 mg vs. 47 ± 40 mg, p = 0.031). CONCLUSIONS: We have shown that sevoflurane was associated with less frequent sore throat than desflurane in patients undergoing orthopedic lower extremity surgery.

Focus prosody of telephone numbers in Tokyo Japanese.

Using production and perception experiments, this study examined whether the prosodic structure inherent to telephone numbers in Tokyo Japanese affects the realization of focus prosody as well as its perception. It was hypothesized that prosodic marking of focus differs by position within the digit groups of phone number strings. Overall, focus prosody of telephone numbers was not clearly marked, resulting in poor identification in perception. However, a difference between positions within digit groups was identified, reflecting a prosodic structure where one position is assigned an accentual peak instead of the other. The findings suggest that, conforming to a language-specific prosodic structure, focus prosody within a language can vary under the influence of a particular linguistic environment.

Remifentanil postconditioning has cross talk with adenosine receptors in the ischemic-reperfused rat heart.

BACKGROUND: Although there is a possibility of cross talk between opioid and adenosine signaling pathways in the ischemic-reperfused myocardium, it is not clear that an ultra-short-acting opioid receptor agonist remifentanil-induced postconditioning (RPostC) has cross talk with adenosine receptor (ADR). The purpose of this study was to determine whether there is cross talk with ADR in RPostC. MATERIALS AND METHODS: Isolated rat hearts were subjected to 30 min of regional ischemia and 2 h of reperfusion. RPostC was induced by 100 ng/mL of remifentanil perfusion, 5 min before reperfusion, followed by 5 min of reperfusion. The nonspecific opioid receptor antagonist naloxone (NAL) and the nonspecific ADR antagonist 8-(p-sulfophenyl) theophylline hydrate (8-SPT) were perfused for a 20-min period, 10 min before RPostC to the end of RPostC. Western blot analysis was performed to detect phospho-ERK1/2 in cultured cardiomyocytes. RESULTS: In cultured cardiomyocytes, remifentanil incubation significantly increased the phosphorylation of ERK1/2 and this effect was blocked by both NAL and 8-SPT (P < 0.01 and P < 0.05, respectively). RPostC significantly reduced infarct size over ischemic area at risk from 34.1 ± 10.5% to 16.6 ± 7.5% (P < 0.05 versus control). The infarct-limitation effect of RPostC was reversed by both NAL (33.8 ± 13.0%, P < 0.05) and 8-SPT (35.7 ± 14.5%, P < 0.01). CONCLUSIONS: This study strongly implies that the intracellular signaling pathways of cardioprotection by RPostC has cross talk with ADR in the ischemic-reperfused myocardium.

Analysis of anesthesia-related medical disputes in the 2009-2014 period using the Korean Society of Anesthesiologists database.

Using the Korean Society of Anesthesiologists database of anesthesia-related medical disputes (July 2009-June 2014), causative mechanisms and injury patterns were analyzed. In total, 105 cases were analyzed. Most patients were aged < 60 yr (82.9%) and were classified as American Society of Anesthesiologists physical status ≤ II (90.5%). In 42.9% of all cases, the injuries were determined to be 'avoidable' if the appropriate standard of care had been applied. Sedation was the sec most common type of anesthesia (37.1% of all cases), following by general anesthesia. Most sedation cases (27/39, 69.2%) showed a common lack of vigilance: no pre-procedural testing (82.1%), absence of anesthesia record (89.7%), and non-use of intra-procedural monitoring (15.4%). Most sedation (92.3%) was provided simultaneously by the non-anesthesiologists who performed the procedures. After the resulting injuries were grouped into four categories (temporary, permanent/minor, permanent/major, and death), their causative mechanisms were analyzed in cases with permanent injuries (n=20) and death (n=82). A 'respiratory events' was the leading causative mechanism (56/102, 54.9%). Of these, the most common specific mechanism was hypoxia secondary to airway obstruction or respiratory depression (n=31). The sec most common damaging event was a 'cardiovascular events' (26/102, 25.5%), in which myocardial infarction was the most common specific mechanism (n=12). Our database analysis demonstrated several typical injury profiles (a lack of vigilance in seemingly safe procedures or sedation, non-compliance with the airway management guidelines, and the prevalence of myocardial infarction) and can be helpful to improve patient safety.

Does restriction of pitch variation affect the perception of vocal emotions in Mandarin Chinese?

This study reports a finding about vocal expressions of emotion in Mandarin Chinese. Production and perception experiments used the same tone and mixed tone sequences to test whether pitch variation is restricted due to the presence of lexical tones. Results showed that the restriction of pitch variation occurred in all high level tone sequences (tone 1 group) with the expression of happiness but did not happen for other dynamic tone groups. However, perception analysis revealed that all the emotions in every tone group received high identification rates; this indicates that listeners used other cues for encoding happiness in the tone 1 group. This study demonstrates that the restriction of pitch variation does not affect the perception of vocal emotions.

Dataset of focus prosody in Japanese phone numbers.

The data in this article present position-dependent variation of focus prosody within phone number strings in Tokyo Japanese. Four acoustic parameters (duration, mean intensity, maximum pitch, and time-normalized pitch contours) are reported to illustrate focus prosody of Japanese phone numbers, separately for broad focus and corrective focus. The data also include four attached files: 1) time-normalized pitch contours for all speakers (Appendix A), 2) aggregated data of duration, mean intensity, and maximum pitch for on-focus effects (Appendix B), 3) a Python script automatically generating target stimuli (Appendix C), and 4) target stimuli used for each focus type (Appendix D). The data set can be used for several research projects including speech recognition, focus study, speaker variation in marking prosodic focus, and prosody modeling in Tokyo Japanese. Detailed discussion of data interpretation can be found in the article entitled "Prosodic focus of telephone numbers in Tokyo Japanese" (Lee et al.).

The influence of high-dose intraoperative remifentanil on postoperative sore throat: a prospective randomized study: A CONSORT compliant article.

BACKGROUND: Endotracheal intubation for general anesthesia causes postoperative sore throat (POST). This study is designed to evaluate the effect of high-dose remifentanil on the incidence of POST in patients after general anesthesia. METHODS: Ninety-two patients scheduled for orthopedic lower extremity surgery under general anesthesia were randomly assigned into 1 of 2 groups. In the high-dose remifentanil (HR) group (n = 46), remifentanil was infused at a rate of 0.25 µg/kg/min and subsequently increased or decreased by 0.05 µg/kg/min per clinical demand. In the low-dose remifentanil (LR) group (n = 46), remifentanil was infused at a rate of 0.05 µg/kg/min. The incidence of POST was monitored at 0, 2, 4, and 24 hours postoperatively. Complications regarding opioids were compared between groups. RESULTS: The overall incidence of POST was higher in the HR group compared with that in the LR group [33 (72%) vs 18 (39%), P = .022]. The incidence of POST at 0, 2, and 24 hours after surgery was higher in the HR group compared with that in the LR group (P < .001, P = .001, and P = .001, respectively). The incidence of postoperative nausea, vomiting, drowsiness, and headache was similar between the groups. The incidence of postoperative shivering was higher in the HR group than in the LR group [10 (22%) vs 2 (4%), difference 17%, 95% CI 2%-33%, P = .027]. CONCLUSION: A relatively large dose of intraoperative remifentanil increased the incidence of POST in patients for orthopedic surgery under general anesthesia. TRIAL REGISTRATION: Clinicaltrials.gov Identifier: NCT03173339.

Stylet angulation of 70 degrees reduces the time to intubation with the GlideScope®: A prospective randomised trial.

Objective The GlideScope® videolaryngoscope provides a good view of the glottis. However, directing and inserting an endotracheal tube is sometimes difficult during intubation with the GlideScope®. In this study, we compared two GlideScope® stylet angulations (90° vs. 70°) in terms of the time to intubation. Methods In total, 162 patients scheduled for elective surgery under general anaesthesia were randomly assigned to one of two groups. In the 90 group ( n = 79), a 90° stylet was used. In the 70 group ( n = 78), a 70° stylet was used. The time to intubation was recorded. The number of intubation attempts was assessed. Results The time to intubation was significantly shorter in the 70 than 90 group [26.0 (23.0-32.0) vs. 37.0 (30.0-43.0) s, respectively]. The first-time intubation success rate was significantly higher and the number of failed intubations was significantly lower in the 70 than 90 group (100% vs. 87% and 0% vs. 6%, respectively). Conclusions This investigation suggests that a 70° angle stylet is superior to a 90° angle stylet for GlideScope® intubation. Trial Registration Clinicaltrials.gov Identifier: NCT02547064.

Mitochondrial ATP-Sensitive Potassium Channels Play a Role in Reducing Both Myocardial Infarction and Reperfusion Arrhythmia in Remote Ischemic Preconditioned Hearts.

BACKGROUND: Mitochondrial ATP-sensitive potassium (mKATP) channels play a role in reperfusion arrhythmias (RAs) in ischemia-reperfusion (I/R) injury. Evidence suggests that remote ischemic preconditioning (RIPC) reduces RAs, however not much is known on the mechanistic role of mKATP in RIPC. We evaluated whether mKATP channels are associated with reducing arrhythmia and infarct size in RIPC. METHODS: Isolated rat hearts received 30 minutes of regional ischemia followed by 2 hours of reperfusion through the Langendorff perfusion system. RIPC was induced by 3 cycles of 5 minutes occlusion and 5 minutes release of the bilateral femoral artery. The animals were randomly divided into 4 groups as follows: 1) CON, I/R injury but not RIPC, 2) RIPC, 3) HD+RIPC, pretreatment of the selective mKATP channel blocker, 5-hydroxydecanoate (5-HD), in RIPC, and 4) HD, pretreatment of 5-HD in CON. Cardiodynamics and infarct size were determined. The severity of arrhythmia was quantitated via the Curtis and Walker scoring system as well as the Lepran scoring system. RESULTS: RIPC significantly reduced the infarct size over AR (25.7 ± 2.6%) compared to CON (37.0 ± 2.6%, P < 0.05). The selective mKATP channel blocker 5-HD significantly inhibited the infarct-reducing effect of RIPC (39.3 ± 3.0%, P < 0.05 vs. RIPC). Additionally, RIPC significantly reduced the arrhythmia score compared to CON (14.6 ± 1.9 to 8.7 ± 0.4, P = 0.023, by Curtis and Walker's system, 16.1 ± 2.1 to 9.1 ± 0.5, P = 0.006, by Lepran's system). The anti-arrhythmic effect of RIPC was blocked by 5-HD (15.5 ± 1.6 and 16.0 ± 1.2, by Curtis and Walker's and Lepran's system, respectively). CONCLUSIONS: The selective mKATP channel blocker, 5-HD, inhibited the infarct-limitation and anti-arrhythmic effect of RIPC. The mKATP channels play a role in the reduction of both infarct size and RAs in RIPC.

The effect of lidocaine jelly on a taper-shaped cuff of an endotracheal tube on the postoperative sore throat: a prospective randomized study: A CONSORT compliant article.

BACKGROUND: Postoperative sore throat (POST) following general anesthesia with endotracheal intubation is a common complication. We hypothesized that lidocaine jelly applied to the tapered cuff of the endotracheal tube (ETT) might decrease the incidence of POST most commonly arising from endotracheal intubation. METHODS: A total of 208 patients under general anesthesia were randomly assigned into 1 of 2 groups. In the lidocaine group (n = 104), the distal part of ETTs with tapered-shaped cuff was lubricated with lidocaine jelly. In the control group (n = 104), the distal part of ETTs with tapered-shaped cuff was lubricated with normal saline. The incidence of POST, hoarseness, and cough in the postanesthesia patients was compared. RESULTS: The overall incidence of POST was higher in the lidocaine group than in the normal saline group [60 (58%) vs 40 (39%), P = .006]. The incidence of POST at 1 hour postoperatively was higher in the lidocaine group than in the normal saline group [53 (51%) vs 32 (31%), P = .003]. The overall incidence of hoarseness for 24 hours postoperatively was comparable (P = .487). The overall incidence of cough for 24 hours postoperatively is higher in the lidocaine group (P = .045). CONCLUSION: The lidocaine jelly applied at the distal part of ETT with tapered-shaped cuff increased the overall incidence of POST in patients undergoing general anesthesia.

Effective Bolus Dose of Sufentanil to Attenuate Cardiovascular Responses in Laryngoscopic Double-Lumen Endobronchial Intubation.

BACKGROUND: Sufentanil is a potent opioid analgesic frequently used in clinical anesthesia. Double-lumen endobronchial intubation induces profound cardiovascular responses in comparison with ordinary endotracheal intubation because of the larger tube diameter and direct irritation of the carina. OBJECTIVES: The purpose of this study was to determine the effective bolus dose of sufentanil to attenuate hemodynamic changes in response to laryngoscopic double-lumen endobronchial intubation. PATIENTS AND METHODS: We randomly assigned 72 patients aged 18 - 65 years and with an American Society of Anesthesiologists physical status of 1 or 2 to one of four sufentanil dose groups: NS, S0.1, S0.2, or S0.3. The respective doses for the groups were as follows: normal saline, 0.1 mcg/kg of sufentanil, 0.2 mcg/kg of sufentanil, and 0.3 mcg/kg of sufentanil. Blood pressure and heart rate were recorded during the pre-anesthesia period at baseline, pre-intubation, immediate post-intubation, and every minute during 5 minutes after intubation. RESULTS: Baseline mean arterial pressures in the NS, S0.1, S0.2, and S0.3 groups were 89.8 ± 12.1, 89.2 ± 10.9, 88.8 ± 13.6, and 90.7 ± 11.1, respectively. At immediate post-intubation, the mean arterial pressures in the NS, S0.1, S0.2, and S0.3 groups were 129.7 ± 14.7, 120.7 ± 14.2, 120.8 ± 17.2, and 96.7 ± 10.4, respectively. At immediate post-intubation, the mean arterial pressure in the NS, S0.1, and S0.2 groups significantly increased from baseline (P < 0.001), but the S0.3 group showed no difference. In the time point comparison at immediate post- intubation, the S0.3 group had a significantly lower mean arterial pressure than did the NS, S0.1, and S0.2 groups (P < 0.001). CONCLUSIONS: We found that 0.3 mcg/kg of sufentanil attenuates cardiovascular responses to double-lumen endobronchial intubation without adverse effects.

Remifentanil-induced preconditioning has cross-talk with A1 and A2B adenosine receptors in ischemic-reperfused rat heart.

The purpose of this study was to determine whether there is a cross-talk between opioid receptors (OPRs) and adenosine receptors (ADRs) in remifentanil preconditioning (R-Pre) and, if so, to investigate the types of ADRs involved in the cross-talk. Isolated rat hearts received 30 min of regional ischemia followed by 2 hr of reperfusion. OPR and ADR antagonists were perfused from 10 min before R-Pre until the end of R-Pre. The heart rate, left ventricular developed pressure (LVDP),velocity of contraction (+dP/dtmax), and coronary flow (CF) were recorded. The area at risk and area of necrosis were measured. After reperfusion, the LVDP, +dP/dtmax,and CF showed a significant increase in the R-Pre group compared with the control group (no intervention before or after regional ischemia). These increases in the R-Pre group were blocked by naloxone, a nonspecific ADR antagonist, an A1 ADR antagonist, and an A2B ADR antagonist. The infarct size was reduced significantly in the R-Pre group compared with the control group. The infarct-reducing effect in the R-Pre group was blocked by naloxone, the nonspecific ADR antagonist, the A1 ADR antagonist, and the A2B ADR antagonist. The results of this study demonstrate that there is cross-talk between ADRs and OPRs in R-Pre and that A1 ADR and A2B ADR appear to be involved in the cross-talk.

Production and Perception of Tone 3 Focus in Mandarin Chinese.

This study uses production and perception experiments to explore tone 3 focus in Mandarin Chinese. Overall, contrastive focus in Mandarin is clearly marked with increased duration, intensity, and pitch range: in the experiments, listeners identified focused syllables correctly more than 90% of the time. However, a tone 3 syllable offers a smaller capacity for pitch range expansion under focus, and also yields less intensity increase; in addition, local dissimilation increases the duration, intensity, and pitch range of adjacent syllables within the same phrase as a focused tone 3 syllable. As a result, tone 3 focus was less well identified by listeners (77.1%). We suggest that the relatively poor identification of tone 3 focus is due to the smaller capacity for pitch range expansion, the confusion from within-phrase local dissimilatory effects, and the relatively weak intensity of tone 3. This study demonstrates that even within a language where purely prosodic marking of focus is clear, the location of prosodic focus can be difficult to identify in certain circumstances. Our results underline the conclusion, established in other work, that prosodic marking of focus is not universal, but is expressed through the prosodic system of each language.

Esophageal perforation after perioperative transesophageal echocardiography: a case report.

BACKGROUND: Transesophageal echocardiography is widely used in cardiac surgery. Transesophageal echocardiography probe insertion and manipulation can injure the esophagus. CASE PRESENTATION: A 76-year-old Asian man was admitted to our hospital for coronary artery bypass graft revascularization surgery. A right carotid endarterectomy was successfully performed 2 days before coronary artery bypass graft revascularization surgery. After the coronary artery bypass graft revascularization surgery was done successfully, postoperative computed tomography and esophagography revealed perforation of the middle esophagus. The patient was managed with fasting, parenteral nutrition, and intravenous antibiotics. CONCLUSIONS: Esophageal perforation can occur with transesophageal echocardiography probe insertion, even without difficulty or resistance, in patients with atherosclerotic disease. Appropriate imaging and vigilance for esophageal injury after a transesophageal echocardiography examination in patients with cardiovascular disease are necessary for appropriate diagnosis and treatment.

Fixation methods for implantable port chamber: comparative study using glue, self-stabilizing leg and suture fixations in rabbits.

OBJECTIVE: To evaluate the fixation strength and tissue reaction of the glue fixation and self-stabilizing leg fixation methods and to compare the results with those of the conventional tagging suture fixation method. MATERIALS AND METHODS: Twelve healthy rabbits were selected and three different methods of implanting the port chamber were employed on the back of each rabbit. A total of thirty six port chambers were implanted with these three different methods, viz. the glue fixation method using tissue adhesive, the self-stabilizing leg method using a self-expandable stabilizing leg, and the suture fixation method. The fixation strength and the gross and histopathologic changes of each fixation method were evaluated at three days, one week, two weeks and four weeks after port implantation. RESULTS: The glue fixation method showed a good fixation strength, which was similar to that of the tagging suture method (p = 0.3486). Five of the six ports (83%) implanted with the glue fixation method which were examined after two weeks showed cracks on the external surface, but this had no adverse effects on their function. A large amount of granulation tissue reaction was found at the bottom of the chamber (p = 0.0025). The fixation with the self-stabilizing leg showed relatively lower fixation strength (p = 0.0043), but no turning-over of the chamber occurred. The fixation strength improved with time after the first week, and minimal granulation tissue reaction was observed with this method. CONCLUSION: The glue fixation method exhibited equal fixation strength compared to the suture fixation, but showed cracking and a large amount of granulation tissue, whereas the fixation with a self-stabilizing leg showed weaker fixation strength.

Effect of tranexamic acid on reducing postoperative blood loss in combined hypotensive epidural anesthesia and general anesthesia for total hip replacement.

STUDY OBJECTIVE: To determine whether the use of tranexamic acid in the setting of hypotension induced by hypotensive epidural anesthesia (HEA) has any additional beneficial effects in reducing perioperative blood loss and transfusion requirements in total hip replacement. DESIGN: Prospective, randomized, double-blinded trial. SETTING: University-affiliated hospital. PATIENTS: 68 adult, ASA physical status 1 and 2 patients undergoing primary unilateral cementless total hip replacement with general anesthesia and HEA. INTERVENTIONS: The HEATA group received a bolus dose of 15 mg/kg of tranexamic acid before surgical incision, followed by a continuous 15 mg/kg infusion until skin closure. The HEA group received normal saline instead of tranexamic acid in the same manner. MEASUREMENTS: Intraoperative blood loss was measured using the difference between the weights of used gauze and the original unused gauze, in addition to the blood volume accumulated in suction bottles. Postoperative blood loss was considered to be the amount of blood accumulated in drainage bags. MAIN RESULTS: There was no significant difference in intraoperative blood loss between the HEA and HEATA groups (251.8 ± 109.9 mL vs. 234.9 ± 93.9 mL), but postoperative blood loss was significantly less in the HEATA group than the HEA group (439.3 ± 171. 6 mL vs. 1074.4 ± 287.1 mL), as was total cumulative blood loss (674.2 ± 216.4 mL vs. 1326.2 ± 347.8 mL). There was no significant difference in intraoperative transfusion incidences, but postoperative transfusion was greater in the HEA group than the HEATA group. CONCLUSIONS: Administration of tranexamic acid combined with hypotensive epidural anesthesia reduced postoperative and total accumulative blood loss and transfusion requirements more than did hypotensive epidural anesthesia alone.

The incidence, risk factors, and prognosis of recurrent venous thromboembolism (VTE) in patients with advanced solid cancers receiving anticoagulation therapy after the diagnosis of index VTE.

UNLABELLED: Patients with cancer have been associated with increased risk of recurrent venous thromboembolism (VTE). However, data on recurrent VTE in Asian patients with advanced solid cancers are limited. METHODS: This study was conducted using data from the Korean VTE registry, which is an ongoing, prospective database. Patients were eligible if they had diagnosed with recurrent/metastatic solid cancers and initiated anticoagulation therapy following index VTE diagnosis. A total of 449 patients were included in this analysis. The 6-month and 12-month cumulative incidences of recurrent VTE were 20.6% and 27.0%, respectively. Isolated pulmonary embolism (PE) (51%) was the most predominant recurrence type. Pancreas as the primary tumor site, poor Eastern Cooperative Oncology Group performance status at the time of index VTE diagnosis, and initial presentation with PE were independent risk factors for developing recurrent VTE. With a median follow-up of 29.1months (range, 1.0-91.2), the median overall survival (OS) was 11.9months. Patients with recurrent VTE had a significantly worse OS than those without recurrent VTE (median, 8.4 vs. 13.0months, respectively; P=0.001). In conclusion, the incidence of recurrent VTE in Korean patients with advanced solid cancers is comparable with Caucasian patients. Pancreas as the primary tumor site, poor performance status, and initial presentation with PE are independent recurrent VTE risk factors in advanced cancer VTE patients. Additionally, OS is adversely affected by recurrent VTE.

Airway obstruction after biopsy by cervical mediastinoscopy in a patient with a mediastinal mass -A case report-.

Biopsy, using mediastinoscopy is commonly employed for accurate histologic diagnosis of a mediastinal mass. However, since the mass is not removed during the procedure, it may cause compression of vital structures such as major airways, the heart, the pulmonary artery, and the superior vena cava after surgery. We observed a case of a 66-year-old man with a mediastinal mass that caused severe airway obstruction during recovery from anesthesia following mediastinoscopic biopsy, probably caused by upper airway edema which seemed to originate from compression of the superior vena cava. Therefore, we suggest that unexpected airway obstruction in a patient with a mediastinal mass can be due to superior vena cava compression.