Risk Factors for the Mortality of Patients With Coronavirus Disease 2019 Requiring Extracorporeal Membrane Oxygenation in a Non-Centralized Setting: A Nationwide Study.

BACKGROUND: Limited data are available on the mortality rates of patients receiving extracorporeal membrane oxygenation (ECMO) support for coronavirus disease 2019 (COVID-19). We aimed to analyze the relationship between COVID-19 and clinical outcomes for patients receiving ECMO. METHODS: We retrospectively investigated patients with COVID-19 pneumonia requiring ECMO in 19 hospitals across Korea from January 1, 2020 to August 31, 2021. The primary outcome was the 90-day mortality after ECMO initiation. We performed multivariate analysis using a logistic regression model to estimate the odds ratio (OR) of 90-day mortality. Survival differences were analyzed using the Kaplan-Meier (KM) method. RESULTS: Of 127 patients with COVID-19 pneumonia who received ECMO, 70 patients (55.1%) died within 90 days of ECMO initiation. The median age was 64 years, and 63% of patients were male. The incidence of ECMO was increased with age but was decreased after 70 years of age. However, the survival rate was decreased linearly with age. In multivariate analysis, age (OR, 1.048; 95% confidence interval [CI], 1.010-1.089; P = 0.014) and receipt of continuous renal replacement therapy (CRRT) (OR, 3.069; 95% CI, 1.312-7.180; P = 0.010) were significantly associated with an increased risk of 90-day mortality. KM curves showed significant differences in survival between groups according to age (65 years) (log-rank P = 0.021) and receipt of CRRT (log-rank P = 0.004). CONCLUSION: Older age and receipt of CRRT were associated with higher mortality rates among patients with COVID-19 who received ECMO.

Prospective, multicenter validation of the deep learning-based cardiac arrest risk management system for predicting in-hospital cardiac arrest or unplanned intensive care unit transfer in patients admitted to general wards.

BACKGROUND: Retrospective studies have demonstrated that the deep learning-based cardiac arrest risk management system (DeepCARS™) is superior to the conventional methods in predicting in-hospital cardiac arrest (IHCA). This prospective study aimed to investigate the predictive accuracy of the DeepCARS™ for IHCA or unplanned intensive care unit transfer (UIT) among general ward patients, compared with that of conventional methods in real-world practice. METHODS: This prospective, multicenter cohort study was conducted at four teaching hospitals in South Korea. All adult patients admitted to general wards during the 3-month study period were included. The primary outcome was predictive accuracy for the occurrence of IHCA or UIT within 24 h of the alarm being triggered. Area under the receiver operating characteristic curve (AUROC) values were used to compare the DeepCARS™ with the modified early warning score (MEWS), national early warning Score (NEWS), and single-parameter track-and-trigger systems. RESULTS: Among 55,083 patients, the incidence rates of IHCA and UIT were 0.90 and 6.44 per 1,000 admissions, respectively. In terms of the composite outcome, the AUROC for the DeepCARS™ was superior to those for the MEWS and NEWS (0.869 vs. 0.756/0.767). At the same sensitivity level of the cutoff values, the mean alarm counts per day per 1,000 beds were significantly reduced for the DeepCARS™, and the rate of appropriate alarms was higher when using the DeepCARS™ than when using conventional systems. CONCLUSION: The DeepCARS™ predicts IHCA and UIT more accurately and efficiently than conventional methods. Thus, the DeepCARS™ may be an effective screening tool for detecting clinical deterioration in real-world clinical practice. Trial registration This study was registered at ClinicalTrials.gov ( NCT04951973 ) on June 30, 2021.

Chemical Burn Injury on the Cornea Following Skin Preparation With Chlorhexidine in Tonsillectomy and Adenoidectomy.

This article report discusses a pediatric patient who suffered a corneal chemical burn injury after tonsillectomy and adenoidectomy surgery due to skin preparation with chlorhexidine. In this case, inadequate sealing of the eye shield during skin preparation allowed the chlorhexidine-alcohol solution to accumulate at its edge and gradually penetrate, resulting in the corneal injury. Prompt ophthalmological intervention and appropriate eye care treatment led to a gradual improvement in the patient's symptoms. The authors aim to present the case, share the revisions made to our skin preparation policy, and emphasize the importance of cautious antiseptic use to minimize the risk of adverse events. Adverse effects of chlorhexidine, such as hypersensitivity reactions and burns, including corneal damage, are highlighted. Health care providers should exercise caution when selecting and applying antiseptics, considering patient-specific factors, and comprehensive training should be provided to promote adherence to safe antiseptic practices during surgical procedures.

Bilateral Nostril Abrasion in Endoscopic Sinus Surgery with Micodebrider.

The emergence of microdebrider technology has revolutionized endoscopic sinus surgery (ESS). Although widely used, it has been associated with complications such as cerebrospinal fluid leakage, ocular and brain injuries, and synechia formation. However, reports on cases of skin abrasion associated with the use of microdebriders in ESS are scarce. We herein present a unique observation of bilateral nostril abrasion after ESS using the microdebrider in a 53-year-old man. The patient underwent ESS and septoplasty for nasal obstruction and polyps. Bilateral nostril erythema and skin abrasion were observed after surgery, which resolved without scarring. Nostril abrasion is attributed to the lever-like use of the microdebrider against the medial aspect of the nostril during the procedure, particularly among inexperienced surgeons. This prompts the need for a cautious approach when using microdebriders in ESS to minimize complications. Increased awareness and precautionary measures can enhance the safety of microdebriders in ESS.

Arrested Pneumatization of the Sphenoid Sinus.

The sphenoid bone is a complex structure in terms of its embryological origin. At birth, the sphenoid sinus is nonpneumatized. Arrested pneumatization of the sphenoid sinus is considered a normal anatomic variant but may be mistaken for disease in imaging studies. We report 2 cases of arrested pneumatization of the sphenoid sinus, a normal variant commonly misdiagnosed as a serious disease of the skull base. A 29-year-old man with a complaint of dizziness visited a local clinic for assessment. Computed tomography (CT) of the paranasal sinuses (PNS) showed a noneroding, nonexpansile, and nonhomogenous lesion in the sphenoid bone. Magnetic resonance imaging (MRI) of the brain revealed a high-signal lesion on both T1-weighted and T2-weighted images. Given these typical findings in the CT of PNS and MRI of the brain, the lesion was diagnosed as arrested pneumatization of the sphenoid sinus. In the second case, a 60-year-old woman with a complaint of headache visited a local clinic for assessment. CT of PNS showed a fibro-osseous lesion (with features of sclerosis and osteolysis) in the skull base. Brain MRI revealed a low-signal lesion on a T1-weighted image containing a high-signal intensity around the sphenoid bone, thereby suggesting internal fat contents. A precise interpretation of CT of PNS and brain MRI is essential to distinguish arrested pneumatization of the sphenoid sinus and to help establish a differential diagnosis and avoid needless biopsy.

Postrhinoplasty Nasal Radix Cyst Treated with Endoscopic Marsupialization.

Postrhinoplasty nasal radix cyst is a rare late complication, with few cases being reported in the literature. The appropriate treatment for this cyst is surgical removal. To date, an open approach or intracartilagenous incision has been performed in most cases. Herein, we present a case of a 68-year-old man with a bulging mass of radix who visited our clinic. The patient underwent open surgery for the mass, but the mass recurred 2 years after surgery. Although removal using the open approach was planned as in the previous surgery, marsupialization was performed because a connection with the frontal recess was seen on a computed tomography scan. We report a rare case of nasal radix cyst successfully treated with marsupialization without an external scar.

Impact of High-Flow Nasal Cannula Oxygenation on the Prevention of Hypoxia During Endoscopic Retrograde Cholangiopancreatography in Elderly Patients: A Randomized Clinical Trial.

BACKGROUND: Hypoxia is the most frequently occurring adverse effect during endoscopic retrograde cholangiopancreatography (ERCP) under sedation; thus, oxygen must be properly supplied to prevent a reduction of oxygen saturation. In this study, we intend to verify the preventive effect for hypoxia during ERCP, using a high-flow nasal cannula (HFNC), in elderly patients. METHODS: As a multicenter prospective randomized trial, patients who underwent ERCP with propofol-based sedation were randomly assigned into two groups: Patients in the HFNC group were supplied with oxygen via an HFNC, and those in the standard nasal cannula group were supplied with oxygen via a low-flow nasal cannula. The co-primary end points were the lowest oxygen saturation rate and hypoxia during the overall procedure. RESULTS: A total of 187 patients (HFNC group: 95; standard nasal cannula group: 92) were included in the analysis. Unexpected hypoxia events were more frequently observed among patients in the standard nasal cannula group than among patients in the HFNC group (13% vs. 4%, odds ratio 3.41, 95% confidence interval 1.06-11.00, p = 0.031). The mean of the lowest oxygen saturation rate during ERCP was significantly lower in the standard nasal cannula group than in the HFNC group (95% vs. 97%, p = 0.002). CONCLUSION: Oxygen supplementation with an HFNC can prevent oxygen desaturation and hypoxia events in patients undergoing ERCP under sedation. Trial registration Clinical Research Information Service (CRIS; KCT0004960).

Quick Sequential Organ Failure Assessment Score and the Modified Early Warning Score for Predicting Clinical Deterioration in General Ward Patients Regardless of Suspected Infection.

BACKGROUND: The quick sequential organ failure assessment (qSOFA) score is suggested to use for screening patients with a high risk of clinical deterioration in the general wards, which could simply be regarded as a general early warning score. However, comparison of unselected admissions to highlight the benefits of introducing qSOFA in hospitals already using Modified Early Warning Score (MEWS) remains unclear. We sought to compare qSOFA with MEWS for predicting clinical deterioration in general ward patients regardless of suspected infection. METHODS: The predictive performance of qSOFA and MEWS for in-hospital cardiac arrest (IHCA) or unexpected intensive care unit (ICU) transfer was compared with the areas under the receiver operating characteristic curve (AUC) analysis using the databases of vital signs collected from consecutive hospitalized adult patients over 12 months in five participating hospitals in Korea. RESULTS: Of 173,057 hospitalized patients included for analysis, 668 (0.39%) experienced the composite outcome. The discrimination for the composite outcome for MEWS (AUC, 0.777; 95% confidence interval [CI], 0.770-0.781) was higher than that for qSOFA (AUC, 0.684; 95% CI, 0.676-0.686; P < 0.001). In addition, MEWS was better for prediction of IHCA (AUC, 0.792; 95% CI, 0.781-0.795 vs. AUC, 0.640; 95% CI, 0.625-0.645; P < 0.001) and unexpected ICU transfer (AUC, 0.767; 95% CI, 0.760-0.773 vs. AUC, 0.716; 95% CI, 0.707-0.718; P < 0.001) than qSOFA. Using the MEWS at a cutoff of ≥ 5 would correctly reclassify 3.7% of patients from qSOFA score ≥ 2. Most patients met MEWS ≥ 5 criteria 13 hours before the composite outcome compared with 11 hours for qSOFA score ≥ 2. CONCLUSION: MEWS is more accurate that qSOFA score for predicting IHCA or unexpected ICU transfer in patients outside the ICU. Our study suggests that qSOFA should not replace MEWS for identifying patients in the general wards at risk of poor outcome.

Patient Discomfort After Rhinoplasty With and Without Osteotomy Under Conscious Sedation.

OBJECTIVE: Many rhinoplasty techniques, including dorsum augmentation and tip surgery, could be performed under conscious sedation rather than general anesthesia. However, as osteotomy is an invasive procedure, it is burdensome for surgeons to perform osteotomy under conscious sedation. As patient ratings of pain and satisfaction when osteotomy is performed under conscious sedation are unknown, this study aimed to determine discomfort of osteotomy performed under conscious sedation. METHODS: Patients who underwent rhinoplasty with conscious sedation were prospectively included in the study. The patients were classified into an osteotomy and a nonosteotomy group. Questionnaires with a visual analog scale ranging from 0 to 10 were utilized to assess patient pain and satisfaction. Patients were also asked whether they would choose conscious sedation for future rhinoplasty operations. To evaluate adverse events, cardiopulmonary vital signs and nausea or vomiting were assessed. RESULTS: Forty-five patients with a mean age of 32.7 years were included in the study. The mean patients' visual analog scale scores for pain and satisfaction were 3.3±2.0 and 7.2±1.9, respectively. Most of the patients [42, (93%)] stated that they would choose conscious sedation again if they had further operations in the future. No significant adverse effects occurred, and there were no significant differences in patients' ratings of pain and satisfaction between osteotomy and nonosteotomy groups when conscious sedation was used. CONCLUSION: Patients' ratings of pain and satisfaction, and a lack of significant adverse effects, indicated that rhinoplasty can be performed under conscious sedation, even with osteotomy.

Extracranial Craniopharyngioma Confined to the Sphenoid Sinus.

ABSTRACT: Craniopharyngioma is rare epithelial tumor that develops along the craniopharyngeal duct, and most of these tumors occur in the sellar and suprasellar regions. Although it rarely occurs in the extracranial region, sphenoid solitary lesions were not reported in previous literature. In this study, we report a case of infrasellar craniopharyngioma within the sphenoid sinus without intracranial lesion. A patient with intermittent headache visited a private clinic and presented with sphenoid lesions based on the Magnetic resonance imaging scan results. The mass was completely removed using endoscopic endonasal transsphenoidal approach without any complications and showed characteristic pathologic findings, which lead to the diagnosis of craniopharyngioma.

Anisakiasis in Palatine Tonsil.

ABSTRACT: Anisakiasis is a parasitic infection caused by ingesting raw or undercooked fish and seafood infected with Anisakis larvae. Anisakis genus is mostly found in the mucosal or submucosal layer of the stomach and intestine. However, the reports of anisakiasis in tonsils are highly uncommon. A 54-year-old woman with clinical features of sore throat and foreign-body sensation for 10 days after eating raw and undercooked fish. A wriggling worm was noted beneath the mucosa of the right palatine tonsil upon endoscopic examination. The worm was immediately removed completely and histological examination revealed anisakiasis. Reports of anisakia-sis in the tonsils are scarce, but it should be considered at the initial physical examination of patients who visit the hospital for sore throat after eating raw fish. We report a case of anisakiasis in the palatine tonsils, which to date has been rarely reported in the literature.

Depletion of ST6GALNACIII retards A549 non-small cell lung cancer cell proliferation by downregulating transferrin receptor protein 1 expression.

Alterations in sialylation of terminal residues of glycoproteins have been implicated in forming tumor-associated glycans. ST6GALNAC transfers sialyl moiety to N-acetylgalactosamine residue via α2,6 linkage. Although the oncogenic characteristics of ST6GALNACI or II have been demonstrated in various cancer cells, the impact of ST6GALNACIII on tumor progression remains undefined. In this study, we evaluated the effect of ST6GALNACIII knockdown on the growth of A549 non-small cell lung cancer cells. ST6GALNACIII depletion resulted in significant retardation in growth of A549 cells under various culture conditions, including collagen-supported 3D culture and anchorage-independent soft agar culture conditions. Liquid chromatography with tandem mass spectrometry revealed that two glycopeptides of transferrin receptor protein 1 (TFR1) containing N-acetylhexosamine-sialic acid were not detected in ST6GALNACIII-depleted A549 cells compared with control cells. Subsequent lectin binding assay, western blotting, and real-time RT-PCR indicated that TFR1 sialylation was not significantly changed, but TFR1 protein and mRNA expressions were decreased after ST6GALNACIII knockdown. However, cell growth retardation by ST6GALNACIII knockdown was partially rescued by TFR1 overexpression. Additionally, TFR1 mRNA degradation was accelerated following ST6GALNACIII knockdown with concomitant reduction in mRNA levels of iron regulatory protein 1 and 2, the upstream regulators of TFR1 mRNA stability. Therefore, our results indicated an important role of ST6GALNACIII in promoting A549 cell growth through quantitative regulation of TFR1 expression and provided therapeutic implications for ST6GALNACIII targeting in tumor growth suppression in vivo.

Relationship between the presence of dedicated doctors in rapid response systems and patient outcome: a multicenter retrospective cohort study.

BACKGROUND: Rapid response systems (RRSs) improve patients' safety, but the role of dedicated doctors within these systems remains controversial. We aimed to evaluate patient survival rates and differences in types of interventions performed depending on the presence of dedicated doctors in the RRS. METHODS: Patients managed by the RRSs of 9 centers in South Korea from January 1, 2016, through December 31, 2017, were included retrospectively. We used propensity score-matched analysis to balance patients according to the presence of dedicated doctors in the RRS. The primary outcome was in-hospital survival. The secondary outcomes were the incidence of interventions performed. A sensitivity analysis was performed with the subgroup of patients diagnosed with sepsis or septic shock. RESULTS: After propensity score matching, 2981 patients were included per group according to the presence of dedicated doctors in the RRS. The presence of the dedicated doctors was not associated with patients' overall likelihood of survival (hazard ratio for death 1.05, 95% confidence interval [CI] 0.93‒1.20). Interventions, such as arterial line insertion (odds ratio [OR] 25.33, 95% CI 15.12‒42.44) and kidney replacement therapy (OR 10.77, 95% CI 6.10‒19.01), were more commonly performed for patients detected using RRS with dedicated doctors. The presence of dedicated doctors in the RRS was associated with better survival of patients with sepsis or septic shock (hazard ratio for death 0.62, 95% CI 0.39‒0.98) and lower intensive care unit admission rates (OR 0.53, 95% CI 0.37‒0.75). CONCLUSIONS: The presence of dedicated doctors within the RRS was not associated with better survival in the overall population but with better survival and lower intensive care unit admission rates for patients with sepsis or septic shock.

The association between hospital length of stay before rapid response system activation and clinical outcomes: a retrospective multicenter cohort study.

BACKGROUND: Rapid response system (RRS) is being increasingly adopted to improve patient safety in hospitals worldwide. However, predictors of survival outcome after RRS activation because of unexpected clinical deterioration are not well defined. We investigated whether hospital length of stay (LOS) before RRS activation can predict the clinical outcomes. METHODS: Using a nationwide multicenter RRS database, we identified patients for whom RRS was activated during hospitalization at 9 tertiary referral hospitals in South Korea between January 1, 2016, and December 31, 2017. All information on patient characteristics, RRS activation, and clinical outcomes were retrospectively collected by reviewing patient medical records at each center. Patients were categorized into two groups according to their hospital LOS before RRS activation: early deterioration (LOS < 5 days) and late deterioration (LOS ≥ 5 days). The primary outcome was 28-day mortality and multivariable logistic regression was used to compare the two groups. In addition, propensity score-matched analysis was used to minimize the effects of confounding factors. RESULTS: Among 11,612 patients, 5779 and 5883 patients belonged to the early and late deterioration groups, respectively. Patients in the late deterioration group were more likely to have malignant disease and to be more severely ill at the time of RRS activation. After adjusting for confounding factors, the late deterioration group had higher 28-day mortality (aOR 1.60, 95% CI 1.44-1.77). Other clinical outcomes (in-hospital mortality and hospital LOS after RRS activation) were worse in the late deterioration group as well, and similar results were found in the propensity score-matched analysis (aOR for 28-day mortality 1.66, 95% CI 1.45-1.91). CONCLUSIONS: Patients who stayed longer in the hospital before RRS activation had worse clinical outcomes. During the RRS team review of patients, hospital LOS before RRS activation should be considered as a predictor of future outcome.

Rapid Response System Should Be Enhanced at Non-general Ward Locations: a Retrospective Multicenter Cohort Study in Korea.

BACKGROUND: A rapid response system (RRS) contributes to the safety of hospitalized patients. Clinical deterioration may occur in the general ward (GW) or in non-GW locations such as radiology or dialysis units. However, there are few studies regarding RRS activation in non-GW locations. This study aimed to compare the clinical characteristics and outcomes of patients with RRS activation in non-GW locations and in the GW. METHODS: From January 2016 to December 2017, all patients requiring RRS activation in nine South Korean hospitals were retrospectively enrolled and classified according to RRS activation location: GW vs non-GW RRS activations. RESULTS: In total, 12,793 patients were enrolled; 222 (1.7%) were non-GW RRS activations. There were more instances of shock (11.6% vs. 18.5%) and cardiac arrest (2.7% vs. 22.5%) in non-GW RRS activation patients. These patients also had a lower oxygen saturation (92.6% ± 8.6% vs. 88.7% ± 14.3%, P < 0.001) and a higher National Early Warning Score 2 (7.5 ± 3.4 vs. 8.9 ± 3.8, P < 0.001) than GW RRS activation patients. Although non-GW RRS activation patients received more intubation (odds ratio [OR], 3.135; P < 0.001), advanced cardiovascular life support (OR, 3.912; P < 0.001), and intensive care unit transfer (OR, 2.502; P < 0.001), their hospital mortality (hazard ratio, 0.630; P = 0.013) was lower than GW RRS activation patients upon multivariate analysis. CONCLUSION: Considering that there were more critically ill but recoverable cases in non-GW locations, active RRS involvement should be required in such locations.

Enhanced method for estimation of flow intercepted by drainage grate inlets on roads.

Determining appropriate road drainage grate installation intervals requires an equation for estimating the flow intercepted by each grate inlet and its interception efficiency. In this study, 720 experiments were performed using a hydraulic model to estimate the flow intercepted by a grate inlet on a road. The flow calculation considered the number of lanes (2-4), longitudinal slope of the road (2-10%), transverse slope of the gutter (2-10%), and design capacity (up to 30 years of rainfall). The experimental results revealed that the flow intercepted by a grate inlet increased with increasing transverse slope of the gutter or the inlet length, thereby increasing its interception efficiency. Intercepted flow estimation equation was derived by regression analysis, and the derived equation was found to be more accurate than an existing empirical equation. The derived equation can thus be used to determine the installation of drainage grate inlets more effectively.

Thrombectomy in acute vertebrobasilar occlusion: a single-centre experience.

PURPOSE: Acute vertebrobasilar occlusion (VBO) has a grave clinical course; however, thrombectomy in VBO patients has rarely been reported. We retrospectively evaluated the clinical and radiological outcomes of thrombectomy in VBO patients. METHODS: From March 2010 to December 2017, 38 patients with 40 acute VBOs underwent thrombectomy at our hospital. Thrombectomy was performed using catheter aspiration (n = 11, 26.8%) or a stent retriever (n = 29, 70.7%). RESULTS: Good clinical outcomes (3-month modified Rankin scale (mRS) of 2 or lower) were achieved in 9 cases (22.5%), and successful recanalization (thrombolysis in cerebral infarction (TICI) grade of 2b or 3) was achieved in 35 cases (87.5%). Good clinical outcomes were significantly related to aetiologies other than atherosclerosis (p = 0.020) and lower National Institutes of Health Stroke Scale (NIHSS) scores on admission (p = 0.025). The clinical and radiological outcomes did not differ significantly between catheter aspiration and stent retriever thrombectomy (p = 1.000 and p = 0.603, respectively); however, stent retriever thrombectomy had a shorter procedure time than catheter aspiration (59.7 ± 31.2 vs. 84.5 ± 35.1 min, p = 0.037). CONCLUSION: In our series, good clinical outcomes were associated with a lower NIHSS score on admission and stroke aetiologies other than atherosclerosis. The two thrombectomy modalities showed similar clinical and radiological outcomes. However, stent retrievers seemed to allow more rapid recanalization than catheter aspiration in VBO.

The Long-term Effectiveness of the Automatic Position-Adaptive System in Spinal Cord Stimulation: A Retrospective Comparative Study with a Two-Year Follow-up.

OBJECTIVE: To compare the nonadaptive manual system with the position-adaptive system in subjects with permanent spinal cord stimulator (SCS) implantation over a two-year follow-up period. DESIGN: Retrospective study. SETTING: Tertiary university-based national hospital. SUBJECTS: Patients who underwent permanent SCS implantation procedures. METHODS: Patients were divided into an adaptive group and a nonadaptive group according to the type of implanted SCS device. The primary outcome was the change (%) in pain intensity from baseline between the adaptive and nonadaptive groups at 24 months after SCS implantation. The secondary outcomes were comparisons of detailed clinical variables such as the scores of patient pain and satisfaction during the two-year follow-up after SCS therapy. Further, the number of subjects with SCS removal or revision within two years after SCS implantation was investigated. RESULTS: Of 187 patients with permanent SCS implantation, 85 in the nonadaptive group and 64 in the position-adaptive group were finally analyzed. The reduction in pain intensity at 24 months was higher in the adaptive group (-38.6%) than in the nonadaptive group (-30.8%, P = 0.05). Similarly, patient satisfaction with the SCS treatment at 24 months was superior in the adaptive group than in the nonadaptive group (85.7% vs 67.5% were satisfied in each group, respectively, P = 0.024). During the two years, 5.3% of patients (N = 10) underwent SCS removal and 7.0% (N = 13) underwent revision procedures. CONCLUSIONS: There was a trend of a sustained reduction in pain intensity as well as improvement in patient satisfaction at two-year follow-up in the position-adaptive system, suggesting long-term benefit over the nonadaptive manual system during SCS treatment.

Phe-140 Determines the Catalytic Efficiency of Arylacetonitrilase from Alcaligenes faecalis.

Arylacetonitrilase from Alcaligenes faecalis ATCC8750 (NitAF) hydrolyzes various arylacetonitriles to the corresponding carboxylic acids. A systematic strategy of amino acid residue screening through sequence alignment, followed by homology modeling and biochemical confirmation was employed to elucidate the determinant of NitAF catalytic efficiency. Substituting Phe-140 in NitAF (wild-type) to Trp did not change the catalytic efficiency toward phenylacetonitrile, an arylacetonitrile. The mutants with nonpolar aliphatic amino acids (Ala, Gly, Leu, or Val) at location 140 had lower activity, and those with charged amino acids (Asp, Glu, or Arg) exhibited nearly no activity for phenylacetonitrile. Molecular modeling showed that the hydrophobic benzene ring at position 140 supports a mechanism in which the thiol group of Cys-163 carries out a nucleophilic attack on a cyanocarbon of the substrate. Characterization of the role of the Phe-140 residue demonstrated the molecular determinant for the efficient formation of arylcarboxylic acids.

Case Report of Patients with Acute Respiratory Distress Syndrome Caused by COVID-19: Successfully Treated by Venovenous Extracorporeal Membrane Oxygenation and an Ultra-Protective Ventilation.

Coronavirus disease (COVID-19) started in Wuhan (China) at the end of 2019, and then increased rapidly. In patients with severe acute respiratory distress syndrome (ARDS) caused by COVID-19, venovenous extracorporeal membrane oxygenation (VV-ECMO) is considered a rescue therapy that provides adequate gas exchange. The way in which mechanical ventilation is applied during VV-ECMO is not clear, however it is associated with prognosis. Currently, the mortality rate of COVID-19 patients that receive VV-ECMO stands at approximately 50%. Here, we report three patients that successfully recovered from COVID-19-induced ARDS after VV-ECMO and implementation of an ultra-protective ventilation. This ventilation strategy involved maintaining a peak inspiratory pressure of ≤20 cmH2O and a positive end-expiratory pressure (PEEP) of ≤ 10 cmH2O, which are lower values than have been previously reported. Thus, we suggest that this ultra-protective ventilation be considered during VV-ECMO as it minimizes the ventilator-induced lung injury.