Prehospital Advanced Airway Management and Ventilation for Out-of-Hospital Cardiac Arrest with Prehospital Return of Spontaneous Circulation: A Prospective Observational Cohort Study in Japan.

BACKGROUND: The relationship among advanced airway management (AAM), ventilation, and oxygenation in patients with out-of-hospital cardiac arrest (OHCA) who achieve prehospital return of spontaneous circulation (ROSC) has not been validated. This study was designed to evaluate ventilation and oxygenation for each AAM technique (supraglottic devices [SGA] or endotracheal intubation [ETI]) using arterial blood gas (ABG) results immediately after hospital arrival. METHODS: This observational cohort study, using data from the Japanese Association for Acute Medicine OHCA Registry, included patients with OHCA with prehospital and hospital arrival ROSC between July 1, 2014, and December 31, 2019. The primary outcomes were the partial pressure of carbon dioxide in the arterial blood (PaCO2) and partial pressure of oxygen in the arterial blood (PaO2) in the initial ABG at the hospital for each AAM technique (SGA or ETI) performed by paramedics. The secondary outcome was favorable neurological outcome (cerebral performance category [CPC] 1 or 2) for specific PaCO2 levels, which were defined as good ventilation (PaCO2 ≤45 mmHg) and insufficient ventilation (PaCO2 >45 mmHg). RESULTS: This study included 1,527 patients. Regarding AAM, 1,114 and 413 patients were ventilated using SGA and ETI, respectively. The median PaCO2 and PaO2 levels were 74.50 mmHg and 151.35 mmHg in the SGA group, while 66.30 mmHg and 173.50 mmHg in the ETI group. PaCO2 was significantly lower in the ETI group than in the SGA group (12.55 mmHg; 95% CI 15.27 to 8.20, P-value < 0.001), while no significant difference was found in PaO2 by multivariate linear regression analysis. After stabilizing inverse probability of weighting (IPW), the adjusted odds ratio for favorable neurological outcome at 1 month was significant in the good ventilation group compared to the insufficient ventilation cohort (adjusted odds ratio = 2.12, 95%CI: 1.40 to 3.19, P value < 0.001). CONCLUSION: The study showed that in OHCA patients with prehospital ROSC, the PaCO2 levels in the initial ABG were lower in the group with AAM by ETI than in the SGA group. Furthermore, patients with prehospital ROSC and PaCO2 ≤45 mmHg on arrival had an increased odds of favorable neurological outcome after stabilized IPW adjustment.

Outcomes of patients suffering unwitnessed hypothermic cardiac arrest rewarmed with extracorporeal life support: A systematic review.

Prolonged cardiac arrest (CA) may lead to neurologic deficit in survivors. Good outcome is especially rare when CA was unwitnessed. However, accidental hypothermia is a very specific cause of CA. Our goal was to describe the outcomes of patients who suffered from unwitnessed hypothermic cardiac arrest (UHCA) supported with Extracorporeal Life Support (ECLS). We included consecutive patients' cohorts identified by systematic literature review concerning patients suffering from UHCA and rewarmed with ECLS. Patients were divided into four subgroups regarding the mechanism of cooling, namely: air exposure; immersion; submersion; and avalanche. A statistical analysis was performed in order to identify the clinical parameters associated with good outcome (survival and absence of neurologic impairment). A total of 221 patients were included into the study. The overall survival rate was 27%. Most of the survivors (83%), had no neurologic deficit. Asystole was the presenting CA rhythm in 48% survivors, of which 79% survived with good neurologic outcome. Variables associated with survival included the following: female gender (P < .001); low core temperature (P = .005); non-asphyxia-related mechanism of cooling (P < .001); pulseless electrical activity as an initial rhythm (P < .001); high blood pH (P < .001); low lactate levels (P = .003); low serum potassium concentration (P < .001); and short resuscitation duration (P = .004). Severely hypothermic patients with unwitnessed CA may survive with good neurologic outcome, including those presenting as asystole. The initial blood pH, potassium, and lactate concentration may help predict outcome in hypothermic CA.

Adaptive Cross-Resistance to Aminoglycoside Antibiotics in Pseudomonas aeruginosa Induced by Topical Dosage of Neomycin.

BACKGROUND: Topical antimicrobial formulations containing neomycin are commonly used to prevent and treat burn infections. However, Pseudomonas aeruginosa shows rapid acquisition of adaptive resistance to neomycin. This study aimed to evaluate the survival of P. aeruginosa during exposure to neomycin at high concentrations comparable to those used in topical formulations, and to investigate the effect of adaptive resistance to neomycin on the susceptibility to other aminoglycosides. METHODS: Strain IID1130 [neomycin minimal inhibitory concentration (MIC) = 4 µg/ml] was incubated on an agar medium containing neomycin at high concentrations (8-4,096 µg/ml), and growing colonies were macroscopically observed. Acquisition of adaptive resistance was examined for 5 P. aeruginosa strains. Cells were sequentially passaged on agar medium containing neomycin with step-wise increased concentrations (8-2,048 µg/ml). To assess reversion of antibiotic susceptibility, the resulting colonies were repeatedly subcultured on antibiotic-free agar plates. RESULTS: Growing IID1130 colonies were macroscopically detected on a neomycin-containing (2,048 µg/ml) agar plate for 48 h. These cells showed increasing MIC for not only neomycin, but also gentamicin and amikacin; the MIC values were occasionally higher than the breakpoints. When the adapted cells were subcultured on antibiotic-free agar, several passages were required for reversion of susceptibility. CONCLUSIONS: Our findings suggest that P. aeruginosa can survive in the presence of neomycin with a concentration typically used in topical dosage forms, and that the acquired adaptive resistance is persistent and is accompanied by cross-resistance to other aminoglycosides.

Takotsubo cardiomyopathy induced by suicidal neck hanging.

BACKGROUND: Takotsubo cardiomyopathy (TC) is an uncommon immune-endocrinologic cause of acute reversible heart failure, generally caused by some form of stress. CASE REPORT: We report a case of TC after hanging for attempted suicide. Upon admission, the patient demonstrated an almost entirely normal electrocardiogram (ECG) and mild hypotension. However, on the third day after hanging, she developed chest and back pain with inverted T waves and QTc prolongation on ECG. Her coronary arteries were normal on angiogram, but the left ventricle showed apical ballooning, consistent with TC. She was treated with an intra-aortic balloon pump and fully recovered. We observed that the QTc interval seemed to be a good guide for clinical course in this case. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: TC should be considered in any acute stressful presentation, and to assist in the diagnosis as TC, we suggest following the QTc on ECG. TC should be taken into consideration in patients after suicide attempt with low blood pressure or an abnormal ECG, including ST segment elevation, T wave inversion, and QTc prolongation.

Outcome from severe accidental hypothermia with cardiac arrest resuscitated with extracorporeal cardiopulmonary resuscitation.

PURPOSE: This study aimed to identify factors of neurologic prognosis in severe accidental hypothermic patients with cardiac arrest. BASIC PROCEDURES: This retrospective observational study was performed in a tertiary care university hospital in Sapporo, Japan (January 1994 to December 2012). We investigated 26 patients with accidental hypothermic cardiac arrest resuscitated with extracorporeal cardiopulmonary resuscitation (ECPR). We evaluated the neurologic outcome in patients who were resuscitated with ECPR at discharge from hospital. MAIN FINDINGS: In those 26 patients, their median age was 50.5 years; and 69.2% were male. The cause of hypothermia was exposure to cold air in 46.1%, submersion in 46.1%, and avalanche in 7.8%. Ten (38.5%) of these patients survived to favorable neurological outcome at discharge. Factors associated with favorable neurological outcome were a cardiac rhythm other than asystole (P = .009), nonasphyxial hypothermia (P = .006), higher pH (P = .01), and lower serum lactate (P = .01). In subgroup analyses, the patients with hypothermic cardiac arrest due to submersion or avalanche (asphyxia group) showed no factors associated with good neurological outcome, whereas the nonasphyxia group showed a significantly lower core temperature (P = .02) and a trend towards a lower serum lactate (P = .09). PRINCIPAL CONCLUSIONS: Patients with hypothermic cardiac arrest due to nonasphyxial hypothermia have improved neurologic outcomes when treated with ECPR compared to patients with asphyxial hypothermic cardiac arrest. Further investigation is needed to develop a prediction rule for patients with nonasphyxial hypothermic cardiac arrest to determine which patients would benefit from treatment with ECPR.

Prediction of the future number of fall-related emergency medical services calls in older individuals.

BACKGROUND: Falls among older individuals contribute significantly to the rise in ambulance transport use. To recognize the importance of future countermeasures, we estimated the projected number and percentage of fall-related emergency medical service (EMS) calls. METHODS: We examined the sex, age group, and location of falls among patients aged ≥ 65 years who contacted emergency services in Sapporo City from 2013 to 2021. Annual fall-related calls per population subgroup were calculated, and trends were analyzed. Four models were used to estimate the future number of fall-related calls from the 2025-2060 projected population: (1) based on the 2022 data, estimates from the 2013-2022 data using (2) Poisson progression, (3) neural network, (4) estimates from the 2013-2019 data using neural network. The number of all EMS calls was also determined using the same method to obtain the ratio of all EMS calls. RESULTS: During 2013-2022, 70,262 fall-related calls were made for those aged ≥ 65 years. The rate was higher indoors among females and outdoor among males in most age groups and generally increased with age. After adjusting for age, the rate increased by year. Future estimates of the number of fall calls are approximately double the number in 2022 in 2040 and three times in 2060, with falls accounting for approximately 11% and 13% of all EMS calls in 2040 and 2060, respectively. CONCLUSION: The number of fall-related EMS calls among older people is expected to increase in the future, and the percentage of EMS calls will also increase; therefore, countermeasures are urgently needed.

Correlation between normally aerated lung and respiratory system compliance at clinical high positive end-expiratory pressure in patients with COVID-19.

Normally aerated lung tissue on computed tomography (CT) is correlated with static respiratory system compliance (Crs) at zero end-expiratory pressure. In clinical practice, however, patients with acute respiratory failure are often managed using elevated PEEP levels. No study has validated the relationship between lung volume and tissue and Crs at the applied positive end-expiratory pressure (PEEP). Therefore, this study aimed to demonstrate the relationship between lung volume and tissue on CT and Crs during the application of PEEP for the clinical management of patients with acute respiratory distress syndrome due to COVID-19. Additionally, as a secondary outcome, the study aimed to evaluate the relationship between CT characteristics and Crs, considering recruitability using the recruitment-to-inflation ratio (R/I ratio). We analyzed the CT and respiratory mechanics data of 30 patients with COVID-19 who were mechanically ventilated. The CT images were acquired during mechanical ventilation at PEEP level of 15 cmH2O and were quantitatively analyzed using Synapse Vincent system version 6.4 (Fujifilm Corporation, Tokyo, Japan). Recruitability was stratified into two groups, high and low recruitability, based on the median R/I ratio of our study population. Thirty patients were included in the analysis with the median R/I ratio of 0.71. A significant correlation was observed between Crs at the applied PEEP (median 15 [interquartile range (IQR) 12.2, 15.8]) and the normally aerated lung volume (r = 0.70 [95% CI 0.46-0.85], P < 0.001) and tissue (r = 0.70 [95% CI 0.46-0.85], P < 0.001). Multivariable linear regression revealed that recruitability (Coefficient = - 390.9 [95% CI - 725.0 to - 56.8], P = 0.024) and Crs (Coefficient = 48.9 [95% CI 32.6-65.2], P < 0.001) were significantly associated with normally aerated lung volume (R-squared: 0.58). In this study, Crs at the applied PEEP was significantly correlated with normally aerated lung volume and tissue on CT. Moreover, recruitability indicated by the R/I ratio and Crs were significantly associated with the normally aerated lung volume. This research underscores the significance of Crs at the applied PEEP as a bedside-measurable parameter and sheds new light on the link between recruitability and normally aerated lung.

Influence of Personal and Work Environments on Work-Life Balance Among Emergency Medical Technicians.

Introduction Work-life balance (WLB) is a critical concern for emergency medical technicians (EMTs) because it significantly affects the provision of comprehensive emergency medical services (EMS). This study investigated personal and work-related factors influencing work-to-family negative spillover (WFNS), a key element of WLB, among EMTs. Methods A web-based survey was conducted from July 26 to September 13, 2021, among EMTs in Hokkaido, Japan. The study included 21 facilities that were randomly selected from 42 fire stations. The Japanese version of the Survey Work-Home Interaction-NijmeGen (SWING-J) was used to measure WFNS. Personal background factors, such as age, sex, years of work experience, and education, were surveyed. We also evaluated work environment factors, such as weekly working hours, monthly night shifts, monthly overtime hours, and yearly paid vacation days. Unpaired Student's t-tests, one-way analysis of variance (ANOVA), and multilevel generalized linear model (MGLM) analyses were used to explore the relationships between WFNS and personal and work-related factors. Results A total of 912 respondents were included in our analysis. They were predominantly male (98.2%), with an average EMT work experience of 12.7 years and a mean WFNS score of 1.16 (standard deviation (SD) = 1.67). MGLM analysis, adjusting for covariates, identified years of work experience (ß = -0.129, p = 0.001), monthly overtime hours (ß = 0.184, p < 0.001), and yearly paid vacation days (ß = -0.170, p < 0.001) as independent factors associated with WFNS. Conclusion This study suggested that adjusting WFNS among EMTs could be achieved by reducing overtime hours and fostering an organized approach to paid leave within the work environment.

Prehospital emergency care family satisfaction scale for care provided by emergency medical technicians: Scale development and validation.

RATIONALE: To date, family satisfaction with emergency medical technicians (EMTs) has only been reported through narrative statements in subjective evaluations. Although a quantitative assessment of healthcare professional satisfaction is desirable, no specific measures have been devised to assess family satisfaction with the healthcare and care provided by EMTs. AIMS AND OBJECTIVES: This study aimed to develop and validate an EMT care family satisfaction scale to measure patient satisfaction with prehospital emergency care. METHODS: The study population comprised 216 family members (N = 216) of patients who used ambulances between November 2020 and May 2021 in a single region in Japan. Questionnaires were distributed to the participants who provided informed consent. An exploratory factor analysis of construct validity was performed to validate the Family Satisfaction Scale. The Cronbach's alpha was used to validate the internal consistency reliability of the scale. RESULTS: The exploratory factor analysis results revealed a four-factor structure: 'explanation and communication,' 'physical treatment,' 'psychological support,' and 'environment in the ambulance.' The Cronbach's range (0.80-0.93) for the total score for each of these four factors and the overall total score confirmed favorable internal reliability of this study. CONCLUSIONS: The family satisfaction scale developed in this study was constructed and validated to highlight the role of EMTs and needs of the families in the prehospital care settings. Moreover, this scale can be applied in the evaluation and consideration of interventions to improve family satisfaction with EMTs.

Trauma-related thyroid storm in adolescents: A case report.

Background: Because of a scant report, it is little known that thyroid storms can occur after trauma, even in adolescence. Significantly, this increases the risk of delaying diagnosis resulting in life-threatening. Case Presentation: A 13-year-old girl was admitted to the emergency department after a traffic accident. Despite receiving comprehensive trauma care, the patient developed hyperthermia and tachycardia that did not respond to temperature management therapy. On the 10th day of her admission, she was diagnosed with a thyroid storm. Treatment for thyroid storm was initiated; thereby, her condition was totally improved. Conclusion: We experienced a case of an adolescent girl, who developed a thyroid storm during the treatment of trauma and could save her life. Clinicians should consider thyroid storm in post-traumatic hyperthermia and tachycardia patients, even in children.

Prevalence, Location, and Interference With Daily Life of Chronic Pain in Long-Term Survivors After Discharge From a Tertiary Emergency Center.

Background This study aimed to investigate the prevalence, location, and characteristics of new-onset chronic pain by using a new definition in long-term survivors after discharge from a tertiary emergency center. Materials and methods We conducted a single-center ambidirectional cohort study from January to May 2022. A survey of patients was conducted by postal mail two to 2.5 years after their discharge from a tertiary emergency center. We used the Brief Pain Inventory to investigate chronic pain parameters, and the painDETECT questionnaire to investigate neuropathic pain. Patient information during hospitalization was collected retrospectively from medical records. Results The survey was sent to 78 patients, 63 (81%) of whom responded and were included in the analysis. Nine of the 63 patients (14%) had new-onset chronic pain. Of these, six (67%) had chronic pain of moderate or severe intensity which interfered with daily life. The most frequent location of chronic pain was the foot/ankle (n=4, 44%). Neuropathic pain was present in four (44%) patients with new-onset chronic pain. Conclusion New-onset chronic pain may occur for up to two to 2.5 years after discharge from a tertiary emergency center, and this may interfere with daily life. Therefore, a follow-up system for chronic pain is warranted.

Extension of Selection Time for the Emergency Destination of Patients with a Fever Due to the Coronavirus Disease 2019 Pandemic: A Difference-in-differences Analysis.

Objective During the coronavirus disease 2019 (COVID-19) pandemic period, an extended total activity time (TAT) in emergency cases has been reported, especially in febrile patients. A brief selection time (ST) regarding the transport of patients to designated hospitals is vital to achieving a good outcome. However, to our knowledge, no studies have reported the impact of the COVID-19 pandemic on the ST. We therefore examined the impact of a fever on the ST for the transportation of emergency patients during the COVID-19 pandemic. Methods We analyzed emergency medical services (EMS) data in Sapporo between January 2015 and December 2020. The primary outcome was the ST for the emergency destination of patients. The secondary outcomes were the number of inquiries, time from emergency call to arrival at the scene [call-to-scene time (CST)], time from arrival at the hospital to return base [arrival-to-return time (ART)], and TAT. We used a multivariable linear regression model to estimate the difference-in-differences effect. Results A total of 383,917 patients who were transported to the hospital were enrolled within the study period. The mean ST was 5.8 minutes in 2019 and 7.1 minutes in 2020. The difference-in-differences analyses showed that the mean ST increased by 2.52 minutes (p<0.001), the mean ART by 3.10 minutes (p<0.001), and the mean TAT by 7.27 minutes (p<0.001) for patients with a fever during the COVID-19 period. Conclusion This study showed that febrile patients had a longer ST, ART, and TAT during the 2020 COVID-19 period. Considering the COVID-19 pandemic and the threat of future pandemics, regional infection control and information-sharing should be conducted to reduce the EMS activity time.

Effect of prehospital advanced airway management on out-of-hospital cardiac arrest due to asphyxia: A JAAM-OHCA registry-based observational study in Japan.

Aim: To investigate the relationship between prehospital advanced airway management (AAM) and neurological outcomes in patients with asphyxia-related out-of-hospital cardiac arrest (OHCA). Methods: We retrospectively analyzed data from the Japanese Association for Acute Medicine OHCA registry between June 2014 and December 2017. Patients with asphyxia-related cardiac arrest aged ≥18 years were included. The primary outcome was a 1-month favorable neurological outcome (cerebral performance category [CPC] 1-2). Results: Of the 34,754 patients in the 2014-2017 JAAM-OHCA Registry, 1956 were included in our analysis. Cerebral performance category 1-2 was observed in 31 patients (1.6%), while CPC 3-5 was observed in 1925 patients (98.4%). Although prehospital AAM was associated with unfavorable neurological outcomes (odds ratio [OR], 0.269; 95% confidence interval [CI], 0.114-0.633; p = 0.003) in the univariate analysis, the association was not significant in the multivariate analysis. Compared with the AAM group, the non-AAM group showed increased rates of cardiac arrest after emergency medical service contact (4.3 vs. 7.2%, p = 0.009) and Glasgow Coma Scale ≥4 at hospital admission (1.9% vs. 4.7%, p = 0.004). Among the 903 patients for whom the time to return of spontaneous circulation (ROSC) could be calculated, the time from witnessed cardiac arrest to ROSC was significantly shorter (median, 8.5 vs. 37.0 min; p < 0.001) for those with favorable neurological outcomes than for those without. Conclusion: Prehospital AAM is not associated with improved neurological outcomes among those with asphyxia-related OHCA. However, the time from cardiac arrest to the first ROSC was significantly shorter among those with favorable outcomes.

Prehospital emergency care patient satisfaction scale [PECPSS] for care provided by emergency medical teams: Scale development and validation.

The purpose of this study was to develop and validate an emergency medical technician (EMT) care patient satisfaction scale to measure patient satisfaction with prehospital emergency care. To date, patient satisfaction surveys of EMTs have been performed subjectively, e using each facility's questionnaire, without the use of a validated patient satisfaction scale. However, no specific scale has been devised to assess patient satisfaction with EMTs. The study population comprised patients who used an ambulance between November 2020 and May 2021 (N = 202). A survey instrument was administered to participants who provided informed consent. In the process of validating the patient satisfaction scale, an exploratory factor analysis (EFA) of construct validity was performed. The results of the EFA showed a factor structure consisting of five factors: "teamwork", "explanation and communication", "physical treatment and psychological support", "quickness of transport", and "environment in the ambulance". In addition, domain and summary scores showed good internal reliability (Cronbach's range = 0.82-0.94). The patient satisfaction scale developed in this study was designed and validated considering the role of EMTs and patients' needs for prehospital care. This scale may be useful in the development of assessments and interventions to improve patient satisfaction with EMTs.

Influence of work and family environment on burnout among emergency medical technicians.

OBJECTIVE: Burnout among emergency medical technicians is a serious problem affecting delivery of quality emergency medical services. Although the repetitive nature of the job and lower education level requirements for technicians have been reported as risk factors, little is known about the influence of burden of responsibility, degree of supervisor support, and home environment on burnout among emergency medical technicians. This study aimed to test the hypothesis that burden of responsibility, degree of supervisor support, and home environment increase burnout probability. METHODS: A web-based survey was conducted among emergency medical technicians in Hokkaido, Japan from July 26, 2021 to September 13, 2021. A total of 21 facilities were randomly selected from 42 fire stations. Prevalence of burnout was measured using the Maslach Burnout-Human Services Survey Inventory (MBI-HSS). Burden of responsibility was measured using a visual analog scale. Occupational background was also measured. Supervisor support was measured using the Brief Job Stress Questionnaire (BJSQ). Family-work negative spillover was measured using the Japanese version of Survey Work-Home Interaction-NijmeGen (SWING). The cutoff value for burnout syndrome was defined as emotional exhaustion≥27 and/or depersonalization≥10. RESULTS: A total of 700 survey respondents were included, and 27 surveys with missing data were excluded. The suspected burnout frequency was 25.6%. Covariates were adjusted using multilevel logistic regression model analysis. Low supervisor support (odds ratio, 1.421; 95% confidence interval, 1.136-1.406; P<0.001) and high family-work negative spillover (odds ratio, 1.264; 95% confidence interval, 1.285-1.571; P<0.001) were independent factors associated with higher probability of burnout. CONCLUSION: This study indicated that focusing on improvement of supervisor support for emergency medical technicians and creating supportive home environments may assist in reducing burnout frequency.

Long-term prognostic significance of gasping in out-of-hospital cardiac arrest patients undergoing extracorporeal cardiopulmonary resuscitation: a post hoc analysis of a multi-center prospective cohort study.

BACKGROUND: Gasping during resuscitation has been reported as a favorable factor for out-of-hospital cardiac arrest. We examined whether gasping during resuscitation is independently associated with favorable neurological outcomes in patients with refractory ventricular fibrillation or pulseless ventricular tachycardia (VF/pVT) undergoing extracorporeal cardiopulmonary resuscitation ECPR. METHODS: Data from a 2014 study on advanced cardiac life support for ventricular fibrillation with extracorporeal circulation in Japan (SAVE-J), which examined the efficacy of ECPR for refractory VF/pVT, were analyzed. The primary endpoint was survival with a 6-month favorable neurological outcome in patients who underwent ECPR with or without gasping during resuscitation. Multivariate logistic regression analysis was performed to evaluate the association between gasping and outcomes. RESULTS: Of the 454 patients included in the SAVE-J study, data from 212 patients were analyzed in this study after excluding those with missing information and those who did not undergo ECPR. Gasping has been observed in 47 patients during resuscitation; 11 (23.4%) had a favorable neurological outcome at 6 months. Multivariate logistic regression analysis showed that gasping during resuscitation was independently associated with a favorable neurological outcome (odds ratio [OR], 10.58 [95% confidence interval (CI) 3.22-34.74]). The adjusted OR for gasping during emergency medical service transport and on arrival at the hospital was 27.44 (95% CI 5.65-133.41). CONCLUSIONS: Gasping during resuscitation is a favorable factor in patients with refractory VF/pVT. Patients with refractory VF/pVT with continuously preserved gasping during EMS transportation to the hospital are expected to have more favorable outcomes.

Dexmedetomidine improves excessive extracellular glutamate-induced synaptic depression (BRAINRES-D-21-00941).

We investigated the effects of dexmedetomidine, a selective α2-adrenergic agonist and a sedative, on excessive glutamate-induced depressions of central excitatory synaptic transmissions in vitro. From the CA1 in rat hippocampal slices, orthodromically elicited population spikes (PSs) and field excitatory postsynaptic potentials (fEPSPs) at 0.1 Hz were simultaneously recorded. ANOVA was used for statistics, and p < 0.05 was accepted as significant. Glutamate (10 mM for 10 min) completely depressed PSs and fEPSPs, which were partially recovered by the following washout for 40 min (57.4 ± 10.2% and 59.9 ± 9.8% of the control, respectively, p < 0.01, n = 6). The recoveries in PSs and fEPSPs were improved by pre-treatment and simultaneous treatment with dexmedetomidine (p < 0.01, n = 6) but were not altered by post-treatment. Dexmedetomidine alone did not alter PSs and fEPSPs. Simultaneous treatment with isoproterenol or dobutamine exacerbated the recoveries in PSs and fEPSPs (p < 0.01, n = 6), but simultaneous treatment with salbutamol, propranolol, phenylephrine or phentramine did not influence the recoveries. Simultaneous treatment with AP5 improved the recoveries in PSs and fEPSPs that were depressed by glutamate alone and by glutamate with dexmedetomidine, isoproterenol or dobutamine (p < 0.01, n = 6). Excessive glutamate depresses glutamatergic excitatory synaptic transmissions by mainly mediating NMDA receptors, and the depressed transmissions are improved by α2-adrenoceptor stimulation but are exacerbated by ß1-adrenoceptor stimulation. Dexmedetomidine has a protective effect on neuronal dysfunctions induced by excessive glutamate, which is one of the main mechanisms of the secondary damage in the central nervous system.

Pneumomediastinum as patient self-inflicted lung injury in patients with acute respiratory distress syndrome due to COVID-19: a case series.

Background: In patients with coronavirus disease (COVID-19) due to severe acute respiratory syndrome coronavirus 2 infection, pneumomediastinum has been increasingly reported in cases of noninvasive oxygen therapy, including high-flow nasal cannula, and invasive mechanical ventilation. However, its pathogenesis is still not understood. Case Presentation: We report two cases of pneumomediastinum in acute respiratory distress syndrome (ARDS) caused by COVID-19. In both cases, control of spontaneous breathing with neuromuscular blocking agents resulted in resolution of pneumoperitoneum. Conclusion: The improvement of pneumomediastinum with control of spontaneous breathing suggested patient self-inflicted lung injury as a possible mechanism in this case series. In ARDS cases with pneumomediastinum, in addition to controlling plateau pressure with conventional lung protective ventilation, spontaneous breathing should be controlled if the patient's inspiratory effort is suspected to be strong.

Correlation between the hysteresis of the pressure-volume curve and the recruitment-to-inflation ratio in patients with coronavirus disease 2019.

BACKGROUND: Since the response to lung recruitment varies greatly among patients receiving mechanical ventilation, lung recruitability should be assessed before recruitment maneuvers. The pressure-volume curve (PV curve) and recruitment-to-inflation ratio (R/I ratio) can be used bedside for evaluating lung recruitability and individualing positive end-expiratory pressure (PEEP). Lung tissue recruitment on computed tomography has been correlated with normalized maximal distance (NMD) of the quasi-static PV curve. NMD is the maximal distance between the inspiratory and expiratory limb of the PV curve normalized to the maximal volume. However, the relationship between the different parameters of hysteresis of the quasi-static PV curve and R/I ratio for recruitability is unknown. METHODS: We analyzed the data of 33 patients with severe coronavirus disease 2019 (COVID-19) who received invasive mechanical ventilation. Respiratory waveform data were collected from the ventilator using proprietary acquisition software. We examined the relationship of the R/I ratio, quasi-static PV curve items such as NMD, and respiratory system compliance (Crs). RESULTS: The median R/I ratio was 0.90 [interquartile range (IQR), 0.70-1.15] and median NMD was 41.0 [IQR, 37.1-44.1]. The NMD correlated significantly with the R/I ratio (rho = 0.74, P < 0.001). Sub-analysis showed that the NMD and R/I ratio did not correlate with Crs at lower PEEP (- 0.057, P = 0.75; and rho = 0.15, P = 0.41, respectively). On the contrary, the ratio of Crs at higher PEEP to Crs at lower PEEP (Crs ratio (higher/lower)) moderately correlated with NMD and R/I ratio (rho = 0.64, P < 0.001; and rho = 0.67, P < 0.001, respectively). CONCLUSIONS: NMD of the quasi-static PV curve and R/I ratio for recruitability assessment are highly correlated. In addition, NMD and R/I ratio correlated with the Crs ratio (higher/lower). Therefore, NMD and R/I ratio could be potential indicators of recruitability that can be performed at the bedside.

Acquisition of a transposon encoding extended-spectrum beta-lactamase SHV-12 by Pseudomonas aeruginosa isolates during the clinical course of a burn patient.

Three of seven clonally related Pseudomonas aeruginosa strains isolated from a burn patient produced the extended-spectrum beta-lactamase (ESBL) SHV-12. Its gene was flanked by two IS26 elements with a large transposon (>24 kb). The transposon also contained at least five IS26 elements and a gene encoding the amikacin resistance determinant aminoglycoside 6'-N-acetyltransferase type Ib [aac(6')-Ib]. It was inserted into the gene PA5317 in the P. aeruginosa chromosome.