Low-flow Time Research Articles

First Description of a Helicopter-Borne ECPR Team for Remote Refractory Out-of-Hospital Cardiac Arrest

Introduction: Access time to extracorporeal cardiopulmonary resuscitation (ECPR) refractory out of hospital cardiac arrest (OHCA) is a crucial factor. In our region, some patients are not eligible to this treatment due to the impossibility to reach the hospital with reasonable delay (ideally 60 min). In order to increase accessibility for patients far from ECPR centers, we developed a helicopter-borne ECPR-team which is sent out to the patient for ECPR implementation on the scene of the OHCA. Methods: We conducted a retrospective monocentric study to evaluate this strategy. The team is triggered by the local emergency medical service and heliborne on the site of the OHCA. All consecutive patients implemented with ECPR by our heliborne ECPR team from January 2014 to December 2017 were included. We analyzed usual CA characteristics, different times (no-flow, low-flow, time between OHCA and dispatch…), and patient outcome. Results: During this 4-year study period, 33 patients were included. Mean age was 43.9 years. Mean distance from the ECPR-team base to OHCA location was 41 km. Mean low-flow time was 110 minutes. Five patients survived with good neurological outcome; 6 patients developed brain death and became organ donors. Conclusion: These results show the possibility to make ECPR accessible for patients far from ECPR centers. Survival rate is non negligible, especially in the absence of therapeutic alternative. An earlier trigger of the ECPR-team could reduce the low-flow time and probably increase survival. This strategy improves equity of access to ECPR and needs to be confirmed by further studies.

Nosocomial infections in in-hospital cardiac arrest patients who undergo extracorporeal cardiopulmonary resuscitation.

BackgroundLittle is known of nosocomial infections (NI) in patients who suffer from in-hospital cardiac arrest who undergoing extracorporeal cardiopulmonary resuscitation. This study aimed to investigate clinical pictures of NI, and the association of NIs with clinical outcomes in in-hospital cardiac arrest patients who undergoing extracorporeal cardiopulmonary resuscitation.MethodsTo evaluate the incidence and clinical characteristics of NI in patients who undergoing extracorporeal cardiopulmonary resuscitation, a retrospective cohort study was conducted in a single tertiary referral center between January 2010 and December 2018. We included adult patients who undergoing extracorporeal cardiopulmonary resuscitation for in-hospital cardiac arrest and excluded patients who were out-of-hospital cardiac arrest or failed ECMO implantation. Clinical characteristics and outcomes were compared between NI and Non-NI patients, or multidrug-resistant (MDR) and non-MDR. The independent risk factors associated with NIs were also analyzed using multivariable logistic regression model.ResultsThirty-five (23.3%) patients developed a NI. These cases included 21 patients with a gram negative (G-) infection, 12 patients with a gram positive (G+) bacterial infection, and two patients with fungal infection. Pneumonia was the most common type of NIs, followed by catheter-related infection. The in-hospital mortality and neurologic outcomes at discharge were not different between the NI and non-NI groups. Multidrug-resistant (MDR) pathogens were detected in 10 cases (28.6%). The MDR NI patients had a higher ICU mortality than did those with non-MDR NI (80% vs. 32%, p = 0.028). Following multivariable adjustment, body mass index (adjusted OR 0.87, 95% CI, 0.77–0.97, p = 0.016) and cardiopulmonary resuscitation to pump on time (adjusted OR 1.04, 95% CI, 1.01–1.06, p = 0.001) were independent predictors of NI development.ConclusionsIn patients who received extracorporeal cardiopulmonary resuscitation, NIs were not associated with an increase in in-hospital mortality. However, NIs with MDR organisms do increase the risk of in-hospital mortality. Lower body mass index and longer low flow time were significant predictors of NI development.

Promising candidates for extracorporeal cardiopulmonary resuscitation for out-of-hospital cardiac arrest

Precise criteria for extracorporeal cardiopulmonary resuscitation (ECPR) are still lacking in patients with out-of-hospital cardiac arrest (OHCA). We aimed to investigate whether adopting our hypothesized criteria for ECPR to patients with refractory OHCA could benefit. This before-after study compared 4.5 years after implementation of ECPR for refractory OHCA patients who met our criteria (Jan, 2015 to May, 2019) and 4 years of undergoing conventional CPR (CCPR) prior to ECPR with patients who met the criteria (Jan, 2011 to Jan, 2014) in the emergency department. The primary and secondary outcomes were good neurologic outcome at 6-months and 1-month respectively, defined as 1 or 2 on the Cerebral Performance Category score. A total of 70 patients (40 with CCPR and 30 with ECPR) were included. For a good neurologic status at 6-months and 1-month, patients with ECPR (33.3%, 26.7%) were superior to those with CCPR (5.0%, 5.0%) (all Ps < 0.05). Among patients with ECPR, a group with a good neurologic status showed shorter low-flow time, longer extracorporeal membrane oxygenation duration and hospital stays, and lower epinephrine doses used (all Ps < 0.05). The application of the detailed indication before initiating ECPR appears to increase a good neurologic outcome rate.

ECPR en 2020 ?

L’arrêt cardiaque prolongé est associé à un taux faible de retour à la circulation (ROSC) et à un mauvais devenir neurologique. La réanimation cardio-pulmonaire assistée par ECMO veno-arterielle, ou eCPR, est proposée depuis plusieurs années dans ces conditions. Dans cette revue, nous allons discuter l’intérêt potentiel et les limitations des l’eCPR tans dans l’arrêt cardiaque intrahospitalier (iHCA) qu’extrahospitalier (oHCA). Dans l’iHCA, l’eCPR semble améliorer le devenir de patients de patients présentant un arrêt cardiaque devant témoin et pour lesquels des manœuvres de réanimation cardiopulmonaires sont entreprises sans délais, et qui par ailleurs ne présentent pas de pathologie terminale. Dans ce contexte, il semble raisonnable de proposer l’eCPR pour des patients sélectionnés présentant un iHCA, pour autant que le centre possède les possibilités d’insérer une ECMO VA. Dans l’oHCA, les résultats sont plus mitigés et fortement dépendant du délai de « low-flow ». Il semble cependant raisonnable de proposer une eCPR à des patients présentant un oHCA devant témoin, pour autant que le délai entre le début de l’arrêt cardiaque et la mise en circulation de l’ECMO soit relativement limité.

Effects of climate anomalies on warm-season low flows in Switzerland

Abstract. Switzerland has faced extended periods of low river flows in recent years (2003, 2011, 2015 and 2018), with major economic and environmental consequences. Understanding the origins of events like these is important for water resources management. In this work, we provide data illustrating the individual and joint contributions of precipitation and evapotranspiration to low flows in both typical and dry years. To quantify how weather drives low flows, we explore how deviations from mean seasonal climate conditions (i.e., climate anomalies) of precipitation and potential evapotranspiration correlate with the occurrence and magnitude of annual 7 d lowest flows (Qmin) during the warm season (May through November) across 380 Swiss catchments from 2000 through 2018. Most warm-season low flows followed periods of below-average precipitation and above-average potential evapotranspiration, and the lowest low flows resulted from both of these drivers acting together. Low-flow timing was spatially variable across Switzerland in all years, including the driest (2003, 2011, 2015 and 2018). Low flows in these driest years were associated with much longer-lasting climate anomalies than the ≤2 month anomalies which preceded typical warm-season low flows in other years. We found that snow water equivalent and winter precipitation totals only slightly influenced the magnitude and timing of warm-season low flows in low-elevation catchments across Switzerland. Our results provide insight into how precipitation and potential evapotranspiration jointly shape warm-season low flows across Switzerland and potentially aid in assessing low-flow risks in similar mountain regions using seasonal weather forecasts.

Abstract 15210: Do Idiopathic Ventricular Fibrillation and Brugada Syndrome Patients Have Favor Outcomes in the Targeted Temperature Management Era?

Introduction: Idiopathic ventricular fibrillation (IVF) including Brugada syndrome (BS) is one of causes of cardiac arrest without prior overt cardiac dysfunction. Hypothesis: We assessed the hypothesis that patents of IVF had favor outcomes than those of non-IVF after cardiac arrest treated with targeted temperature management (TTM). Methods: Patients who were treated with TTM after cardiac arrest between 2000 and 2019 were enrolled in the study. Patients were divided into 2 groups according to whether the patients were diagnosed as IVF or not. The patients treated with TTM were routinely performed coronary angiography. Results: Among the study patients (N = 306), 35 (11%) patients were IVF and 7 were BS. The patients of the IVF group were significantly younger (median 53 y vs. 64 y) than those of the non-IVF group. The prevalence of initial rhythm was shockable (69% vs. 47%, P = 0.02) was significantly higher in the patients of the IVF group than those of the non-IVF group. Among the patients in the non-IVF group, 114 patients (42%) were diagnosed as acute coronary syndrome and 93 patients (35%) were treated with coronary revascularization. The prevalence of male sex (77% vs 74%, P = 0.70) and witnessed to arrest (80% vs. 81%, P = 0.87), and low-flow time (29 min vs. 38 min [20 - 43 min vs. 21 - 52 min, P = 0.15]) were similar between the 2 groups. The prevalence of performing extracorporeal resuscitation (9% s 43%, P &lt; 0.001) were lower in the patients of the IVF group. The 8-y survival rate were shown in the figure. All of the BS patients were witnessed arrest and were discharged without severe neurological deficit. The IVF as the cause of arrest was independently associated with 8-y survival. Conclusions: The patients of IVF had favor outcomes than those of non-VF. One of causes may be the lower prevalence of requiring extracorporeal circulatory support due to less cardiac dysfunction. The patients of BS had the tendency toward higher survival rate than those of non-BS IVF patients.

Sequential Use of Normothermic Regional and Ex Situ Machine Perfusion in Donation After Circulatory Death Liver Transplant.

In Italy, 20minutes of a continuous flat line on an electrocardiogram are required for declaration of death. In the setting of donation after circulatory death (DCD), prolonged warm ischemia time prompted the introduction of abdominal normothermic regional perfusion (NRP) followed by postprocurement ex situ machine perfusion (MP). This is a retrospective review of DCD liver transplantations (LTs) performed at 2 centers using sequential NRP and ex situ MP. From January 2018 to April 2019, 34 DCD donors were evaluated. Three (8.8%) were discarded before NRP, and 11 (32.4%) were discarded based on NRP parameters (n=1, 3.0%), liver macroscopic appearance at procurement and/or biopsy results (n=9, 26.5%), or severe macroangiopathy at back-table evaluation (n=1, 3.0%). A total of 20 grafts (58.8%; 11 uncontrolled DCDs, 9 controlled DCDs) were considered eligible for LT, procured and perfused ex situ (9 normothermic and 11 dual hypothermic MPs). In total, 18 (52.9%; 11 uncontrolled) livers were eventually transplanted. Median (interquartile range) no-flow time was 32.5 (30-39) minutes, whereas median functional warm ischemia time was 52.5 (47-74) minutes (controlled DCD), and median low-flow time was 112 minutes (105-129 minutes; uncontrolled DCD). There was no primary nonfunction, while postreperfusion syndrome occurred in 8 (44%) recipients. Early allograft dysfunction happened in 5 (28%) patients, while acute kidney injury occurred in 5 (28%). After a median follow-up of 15.1 (9.5-22.3) months, 1 case of ischemic-type biliary lesions and 1 patient death were reported. DCD LT is feasible even with the 20-minute no-touch rule. Strict NRP and ex situ MP selection criteria are needed to optimize postoperative results.

Clinical Significance of Low-Flow Time in Patients Undergoing Extracorporeal Cardiopulmonary Resuscitation: Results from the RESCUE Registry.

Limited data are available on the association between low-flow time and survival in patients with in-hospital cardiac arrest (IHCA) who undergo extracorporeal cardiopulmonary resuscitation (ECPR). We evaluated data from 183 IHCA patients who underwent ECPR as a rescue procedure. Patients were divided into two groups: patients undergoing extracorporeal membrane oxygenation as an adjunct to standard cardiopulmonary resuscitation for less than 38 min (n = 110) or for longer than 38 min (n = 73). The ECPR ≤ 38 min group had a significantly greater incidence of survival to discharge compared to the ECPR > 38 min group (40.0% versus 24.7%, p = 0.032). The incidence of good neurologic outcomes at discharge tended to be greater in the ECPR ≤ 38 min group than in the ECPR > 38 min group (35.5% versus 24.7%, p = 0.102). The incidences of limb ischemia (p = 0.354) and stroke (p = 0.805) were similar between the two groups, but major bleeding occurred less frequently in the ECPR ≤ 38 min group compared to the ECPR > 38 min group (p = 0.002). Low-flow time ≤ 38 min may reduce the risk of mortality and fatal neurologic damage and could be a measure of optimal management in patients with IHCA.

Out-of-hospital cardiac arrest patients with an initial non-shockable rhythm could be candidates for extracorporeal cardiopulmonary resuscitation: a retrospective study

BackgroundExtracorporeal cardiopulmonary resuscitation (ECPR) is a promising treatment for refractory out-of-hospital cardiac arrest (OHCA). Most studies evaluating the effectiveness of ECPR include patients with an initial shockable rhythm. However, the effectiveness of ECPR for patients with an initial non-shockable rhythm remains unknown. This retrospective single-center study aimed to evaluate the effectiveness of ECPR for patients with an initial non-shockable rhythm, with reference to the outcomes of OHCA patients with an initial shockable rhythm.MethodsAdult OHCA patients treated with ECPR at our center during 2011–2018 were included in the study. Patients were classified into the initial shockable rhythm group and the non-shockable rhythm group. The primary outcome was the cerebral performance category (CPC) scale score at hospital discharge. A CPC score of 1 or 2 was defined as a good outcome.ResultsIn total, 186 patients were eligible. Among them, 124 had an initial shockable rhythm and 62 had an initial non-shockable rhythm. Among all patients, 158 (85%) were male, with a median age of 59 (interquartile range [IQR], 48–65) years, and the median low flow time was 41 (IQR, 33–48) min. Collapse was witnessed in 169 (91%) patients, and 36 (19%) achieved return of spontaneous circulation (ROSC) transiently. Proportion of female patients, presence of bystander cardiopulmonary resuscitation, and collapse after the arrival of emergency medical service personnel were significantly higher in the non-shockable rhythm group. The rate of good outcomes at hospital discharge was not significantly different between the shockable and non-shockable groups (19% vs. 16%, p = 0.69). Initial shockable rhythm was not significantly associated with good outcome after controlling for potential confounders (adjusted odds ratio 1.58, 95% confidence interval: 0.66–3.81, p = 0.31). In the non-shockable group, patients with good outcomes had a higher rate of transient ROSC, and pulmonary embolism was the leading etiology.ConclusionsThe outcomes of patients with an initial non-shockable rhythm are comparable with those having an initial shockable rhythm. OHCA patients with an initial non-shockable rhythm could be candidates for ECPR, if they are presumed to have reversible etiology and potential for good neurological recovery.

Advanced Resuscitation Measures: Extracorporeal Cardiopulmonary Resuscitation

An extracorporeal cardiopulmonary resuscitation (eCPR) is considered as a therapy option for cardiovascular failure that is refractory to therapy. It can significantly improve the survival rate with favourable neurological results in highly selected patients. The initially defibrillatable heart rhythm and the short low-flow time < 60 minutes are of particular prognostic value. An essential prerequisite for deciding on eCPR is the existence of a reversible cause for cardiac arrest. Whether an eCPR directly at the emergency site (out-of-hospital variant) or in the clinic, e.g. in the cardiac catheterization laboratory (in-hospital variant) can be recommended must be clarified in further randomized-controlled, multicentre studies. Both variants have advantages and disadvantages. With the out-of-hospital eCPR, the "collapse-to-start-eCPR-time" can be significantly reduced under certain conditions. With the in-hospital eCPR external negative influences can be greatly minimized.

Timing of inducing therapeutic hypothermia in patients successfully resuscitated after out-of-hospital cardiac arrest

Background: Therapeutic hypothermia can improve neurological status in cardiac arrest survivors. Objectives: We investigated the association between the timing of inducing therapeutic hypothermia and neurological outcomes in patients who experienced out-of-hospital cardiac arrest. Methods: We evaluated data from 116 patients who were comatose after return of spontaneous circulation and those who received therapeutic hypothermia between January 2013 and April 2017. The primary endpoint was good neurological outcomes during index hospitalization, defined as a cerebral performance category score of 1 or 2. Therapeutic hypothermia timing was defined as the duration from the return of spontaneous circulation to hypothermia initiation. We analyzed the effect of early hypothermia induction on neurological results. Results: In total, 112 patients were enrolled. The median duration to hypothermia initiation was 284 min (25th–75th percentile, 171–418 min). Eighty-two (69.5%) patients underwent hypothermia within 6 h, and 30 (25.4%) had good neurological outcomes. The rates of good neurological outcomes by hypothermia initiation time quartile (shortest to longest) were 28.3%, 34.5%, 14.8%, and 28.6% (p = 0.401). The good neurologic outcomes did not differ between hypothermia patients within 6 h or after (26.5% vs 26.7%, p = 0.986). Short low-flow time and bystander resuscitation were associated with good neurological outcomes (p = 0.044, confidence interval: 0.027–0.955), but the timing of hypothermia initiation was not (p = 0.602, confidence interval: 0.622–1.317). Conclusion: A shorter low-flow time was associated with good neurological outcomes in out-of-hospital cardiac arrest patients who experienced hypothermia. However, inducing hypothermia sooner, even within 6 h, did not improve the neurological outcomes. Thus, as current guidelines recommend, initiating hypothermia within 6 h of recovery of spontaneous circulation is reasonable.

The Impact of Hypoxic Hepatitis on Clinical Outcomes after Extracorporeal Cardiopulmonary Resuscitation.

Although there have been several reports regarding the association between hypoxic hepatic injury and clinical outcomes in patients who underwent conventional cardiopulmonary resuscitation (CPR), limited data are available in the setting of extracorporeal CPR (ECPR). Patients who received ECPR due to either in- or out-of-hospital cardiac arrest from May 2004 through December 2018 were eligible. Hypoxic hepatitis (HH) was defined as an increased aspartate aminotransferase or alanine aminotransferase level to more than 20 times the upper normal range. The primary outcome was in-hospital mortality. In addition, we assessed poor neurological outcome defined as a Cerebral Performance Categories score of 3 to 5 at discharge and the predictors of HH occurrence. Among 365 ECPR patients, 90 (24.7%) were identified as having HH. The in-hospital mortality and poor neurologic outcomes in the HH group were significantly higher than those of the non-HH group (72.2% vs. 54.9%, p = 0.004 and 77.8% vs. 63.6%, p = 0.013, respectively). As indicators of hepatic dysfunction, patients with hypoalbuminemia (albumin < 3 g/dL) or coagulopathy (international normalized ratio > 1.5) had significantly higher mortalities than those of their counterparts (p = 0.005 and p < 0.001, respectively). In multivariable logistic regression, age and acute kidney injury requiring continuous renal replacement therapy were predictors for development of HH (p = 0.046 and p < 0.001 respectively). Furthermore age, arrest due to ischemic heart disease, initial shockable rhythm, out-of-hospital cardiac arrest, lowflow time, continuous renal replacement therapy, and HH were significant predictors for in-hospital mortality. HH was a frequent complication and associated with poor clinical outcomes in ECPR patients.

The challenges of hydrological drought definition, quantification and communication: an interdisciplinary perspective

Abstract. Numerous indices exist for the description of hydrological drought. The EURO FRIEND-Water Low flow and Drought Group has repeatedly discussed changing paradigms in the perception and use of existing and emerging new indices for hydrological drought identification and characterization. Group members have also tested the communication of different indices to stakeholders in several national and international transdisciplinary research projects. This contribution presents the experience gained with regard to the purpose and applicability of different classes of drought indices. A recent paradigm shift is the use of anomalies, traditionally from climatology, in hydrology. For instance, anomaly-based indices, such as the Standardized Streamflow Index (SSI) and the variable threshold level method to define streamflow deficiencies, are used increasingly for real-time monitoring. How these indices relate to low flows and their impacts may have become less clear as a result. Assessments of the severity of a particular drought may also differ depending on whether return periods based on traditional low flow or drought frequency analyses or whether SSI time series index values are used. These experiences call for a systematic comparison, classification and evaluation of different low flow and drought indices and their usages.

Blood lactate predicts survival after percutaneous implantation of extracorporeal life support for refractory cardiac arrest or cardiogenic shock complicating acute coronary syndrome: insights from the CareGem registry

Refractory cardiogenic shock (RCS) or refractory cardiac arrest (RCA) complicating acute coronary syndrome (ACS) is associated with extremely high mortality rate. Veno-arterial extracorporeal life support (VA-ECLS) represents a valuable therapeutic option to stabilize patients’ condition before or at the time of emergency revascularization. We analyzed 29 consecutive patients with RCS or RCA complicating ACS, and implanted with VA-ECLS in two centers who have adopted a similar, structured approach to ECLS implantation. Data were collected from January 2010 to December 2015 and ECLS had to be percutaneously implanted either before (within 48 h) or at the time of attempted percutaneous coronary revascularization (PCI). We investigated in-hospital outcome and factors associated with survival. Twenty-one (72%) were implanted for RCA, whereas 8 (28%) were implanted on ECLS for RCS. All RCA were witnessed and no-flow time was shorter than 5 min in all cases but one. All patients underwent attempted emergency PCI, using radial access in ten cases (34.5%), whereas in three patients a subsequent CABG was performed. Overall, ten patients (34.5%) survived, nine of them with a good neurological outcome. Life threatening complications, including stroke (4 pts), leg ischemia (4 pts), intestinal ischemia (5 pts), and deep vein thrombosis 2 pts), occurred frequently, but were not associated with in-hospital death. Main cause of death was multi-organ failure. PCI variables did not predict survival. Survivors were younger, with shorter low-flow time, and with ECLS mainly implanted for RCS. At multivariate analysis, levels of lactate at ECLS implantation (OR 4.32, 95%CI 1.01–18.51, p = 0.049) emerged as the only variable that independently predicted survival. In patients with RCA or RCS complicating ACS who are percutaneously implanted with ECLS before or at the time of coronary revascularization, in hospital survival rate is higher than 30%. Level of lactate at ECLS implantation appears to be the most important factor to predict survival.

Extracorporeal cardiopulmonary resuscitation: tool or toy?

Neurological outcome and quality of live are of uttermost interest in survivors of cardiac arrest. Assuming acceptable rates of return of spontaneous circulation, the long-term effects on neurological function and quality of live after cardiopulmonary resuscitation remain unsatisfactory. Extracorporeal cardiopulmonary resuscitation (eCPR) can reduce low-flow times and therefore provide adequate cerebral tissue perfusion and oxygenation. This may improve favorable outcomes after cardiac arrest. Due to the risk of procedure related complications and ethical issues, this technique should be only performed in selected patients by specially trained and experienced teams. In this review we aimed at providing an insight into the sparse evidence in this field and discussing ethical issues associated with the use of eCPR.

Extracorporeal cardiopulmonary resuscitation without target temperature management for out-of-hospital cardiac arrest patients prolongs the therapeutic time window: a retrospective analysis of a nationwide multicentre observational study in Japan

BackgroundExtracorporeal cardiopulmonary resuscitation (ECPR) with extracorporeal membrane oxygenation (ECMO) is a promising therapy for out-of-hospital cardiac arrest (OHCA) compared with conventional cardiopulmonary resuscitation (CCPR). The no and low-flow time (NLT), the interval from collapse to reperfusion to starting ECMO or to the return of spontaneous circulation (ROSC) in CCPR, is associated with the neurological outcome of OHCA. Because the effects of target temperature management (TTM) on the outcomes of ECPR are unclear, we compared the neurological outcomes of OHCA between ECPR and CCPR without TTM.MethodsWe performed retrospective subanalyses of the Japanese Association for Acute Medicine OHCA registry. Witnessed cases of adult cardiogenic OHCA without TTM were selected. We performed univariate, multivariable and propensity score analyses to compare the neurological outcomes after ECPR or CCPR in all eligible patients and in patients with NLT of > 30 min or > 45 min.ResultsWe analysed 2585 cases. Propensity score analysis showed negative result in all patients (odds ratio 0.328 [95% confidence interval 0.141–0.761], P = 0.010). However, significant associated with better neurological outcome was shown in patients with NLT of > 30 min or > 45 min (odds ratio 2.977 [95% confidence interval 1.056–8.388], P = 0.039, odds ratio 5.099 [95% confidence interval 1.259–20.657], P = 0.023, respectively).ConclusionThis study revealed significant differences in the neurological outcomes between ECPR and CCPR without TTM, in patients with NLT of > 30 min.

Both Forest Harvesting and Hydropower Dams Yielded Negative Impact on Low Flow Regimes in the Zagunao River Watershed, Southwest China

Forest harvesting and hydropower dams can significantly affect flow regimes (magnitude, timing, duration, frequency, and variability), resulting in changes in degraded aquatic ecosystems and unstable water supply. Despite numerous studies on the effects of forest harvesting on mean flows, the impact of forest harvesting on flow regimes has been less investigated. A great difficulty lies in separating the hydrological effect of forest harvesting from that of climate variability and other watershed disturbances such hydropower dams. In this study, the Upper Zagunao River watershed (2242 km2) was selected as an example to provide a quantitative assessment of the effects of forest harvesting and hydropower dams on low flow regimes. The key findings include: (1) Forest harvesting led to a significant reduction in the magnitude and return period of low flows, and a significant increment in the variability and duration of low flows; (2) the recovery of low flow regimes occurred 40 years after forest harvesting as forest recovery processed; and (3) hydropower dams caused significant impact on all components of low flow regimes, e.g., a reduction in the magnitude, return period, and timing of low flows, and an increment in the variability and duration of low flows. Our findings highlight the negative impact of both forest harvesting and hydropower dams on low flow regimes in the Upper Zagunao River watershed. A watershed management strategy for offsetting the negative effect of hydropower dams on low flow regimes by restoring hydrological functions of subalpine forests is highly recommended in subalpine watersheds of the Upper Yangtze River.

Long-Term Disabilities of Survivors of Out-of-Hospital Cardiac Arrest: The Hanox Study

Long-term outcomes of awakened survivors of out-of-hospital cardiac arrest (OHCA) are poorly known. What are the month (M) 18 outcomes of survivors of out-of-hospital cardiac arrest (OHCA) who awakened during the first 2weeks' post-OHCA and their poor-outcome risk factors? All OHCA survivors with a Glasgow Coma Scale score≥12 during the first 2weeks' post-OHCA were enrolled in six ICUs and followed up at M3, M6, M12, and M18. The primary outcome measure was Glasgow Outcome Scale-Extended (GOS-E) score at M18. Secondary outcome measures included evaluation at M18 of neurologic, behavioral, and cognitive disabilities; health-related quality of life (HR-QOL), anxiety and depression; and poor-outcome risk factors (GOS-E score≤ 6). Among the 139 included patients, 98 were assessable for the primary outcome measure. At M18, 64 (65%) had full recovery or minor disabilities (GOS-E score > 6), 18 (18%) had moderate disabilities but were autonomous for daily-life activities (GOS-E score= 6), 12 (12%) had poor autonomy (GOS-E score< 6 but > 1), and four had died. Percentages of patients with GOS-E scores > 6 increased significantly over the 18-month study period. At M18, no patients had major neurologic disabilities, 20%had cognitive disabilities, 32%had anxiety symptoms, 25%had depression symptoms, and their HR-QOL was impaired compared with a sex- and age-matched population. Low-flow time, Sequential Organ Failure Assessment score at admission, coma duration > 3days after cardiac arrest, and mechanical ventilation on days 3 and 7 were associated with poor functional outcome. Among patients who awoke (Glasgow Coma Scale score≥12) in the 14days following OHCA, 35%had moderate to severe disabilities or had died at M18. Interestingly, patients improved until M18 post-OHCA. Risk factors associated with poor functional outcome were low-flow time, clinical severity at ICU admission, prolonged coma duration, and mechanical ventilation. ClinicalTrials.gov; No.: NCT02292147; URL: www.clinicaltrials.gov.

Can we predict patient outcome before extracorporeal membrane oxygenation for refractory cardiac arrest?

BackgroundRefractory cardiac arrest resistant to conventional cardiopulmonary resuscitation (C-CPR) has a poor outcome. Although previous reports showed that extracorporeal cardiopulmonary resuscitation (E-CPR) can improve the clinical outcome, there are no clinically applicable predictors of patient outcome that can be used prior to the implementation of E-CPR. We aimed to evaluate the use of clinical factors in patients with refractory cardiac arrest undergoing E-CPR to predict patient outcome in our institution.MethodsThis is a single-center retrospective study. We report 112 patients presenting with refractory cardiac arrest resistant to C-CPR between January 2012 and November 2017. All patients received E-CPR for continued life support when a cardiogenic etiology was presumed. Clinical factors associated with patient outcome were analyzed. Significant pre-ECMO clinical factors were extracted to build a patient outcome risk prediction model.ResultsThe overall survival rate at discharge was 40.2, and 30.4% of patients were discharged with good neurologic function. The six-month survival rate after hospital discharge was 36.6, and 25.9% of patients had good neurologic function 6 months after discharge. We stratified the patients into low-risk (n = 38), medium-risk (n = 47), and high-risk groups (n = 27) according to the TLR score (low-flow Time, cardiac arrest Location, and initial cardiac arrest Rhythm) that we derived from pre-ECMO clinical parameters. Compared with the medium-risk and high-risk groups, the low-risk group had better survival at discharge (65.8% vs. 42.6% vs. 0%, p < 0.0001) and at 6 months (60.5% vs. 38.3% vs. 0%, p = 0.0001). The low-risk group also had a better neurologic outcome at discharge (50% vs. 31.9% vs. 0%, p = 0.0001) and 6 months after discharge (44.7% vs. 25.5% vs. 0%, p = 0.0003) than the medium-risk and high-risk groups.ConclusionsPatients with refractory cardiac arrest receiving E-CPR can be stratified by pre-ECMO clinical factors to predict the clinical outcome. Larger-scale studies are required to validate our observations.

Initial pH and shockable rhythm are associated with favorable neurological outcome in cardiac arrest patients resuscitated with extracorporeal cardiopulmonary resuscitation.

BackgroundThere is uncertainty about best selection criteria for extracorporeal cardiopulmonary resuscitation (eCPR) in the setting of refractory cardiac arrest. We aimed to identify factors associated with a favorable neurological outcome, and to build a score calculable at the time of ECMO insertion predicting the prognosis.MethodsRetrospective analysis of all patients who underwent eCPR between 2010 and 2017 in a single university hospital. Primary end point was survival with favorable neurological outcome at intensive care unit (ICU) discharge defined as a Cerebral Performance Category of 1 or 2.ResultsOverall low-flow time of the 113 included patients was 84 [55–122] minutes. Eighteen patients (16%) survived with a favorable neurological outcome. By multivariate logistic regression analysis, initial shockable rhythm, and arterial blood pH at the time of eCPR implantation ≥7.0, were independent predictors of survival with favorable neurological outcome. All of the patients presenting with both non-shockable rhythm and pH <7.0 at the time of eCPR implantation died in the ICU.ConclusionsAt the time of eCPR start, only initial shockable rhythm and arterial pH ≥7.0 predicted neurological outcome. A selection of the patients who might benefit from eCPR, based upon initial rhythm and arterial pH rather than on low flow time, should be further evaluated.