Prognostication after cardiac arrest

Hypoxic-ischaemic brain injury (HIBI) is the main cause of death in patients who are comatose after resuscitation from cardiac arrest. A poor neurological outcome-defined as death from neurological cause, persistent vegetative state, or severe neurological disability-can be predicted in these patients by assessing the severity of HIBI. The most commonly used indicators of severe HIBI include bilateral absence of corneal and pupillary reflexes, bilateral absence of N 2 O waves of short-latency somatosensory evoked potentials, high blood concentrations of neuron specific enolase, unfavourable patterns on electroencephalogram, and signs of diffuse HIBI on computed tomography or magnetic resonance imaging of the brain. Current guidelines recommend performing prognostication no earlier than 72 h after return of spontaneous circulation in all comatose patients with an absent or extensor motor response to pain, after having excluded confounders such as residual sedation that may interfere with clinical examination. A multimodal approach combining multiple prognostication tests is recommended so that the risk of a falsely pessimistic prediction is minimised

Neurologic prognostication: Neurologic examination and current guidelines

Clinical examination is paramount for prognostication in patients who are comatose after resuscitation from cardiac arrest. At 72 hours from recovery of spontaneous circulation (ROSC), an absent or extensor motor response to pain (M ≤ 2) is a very sensitive, but not specific predictor of poor neurologic outcome. Bilaterally absent pupillary or corneal reflexes are less sensitive, but highly specific predictors. Besides the clinical examination, investigations such as somatosensory evoked potentials (SSEPs), electroencephalography (EEG), blood levels of neuron-specific enolase (NSE), or imaging studies can be used for neuroprognostication. In patients who have not been treated using targeted temperature management (TTM), the 2006 Practice Parameter of the American Academy of Neurology suggested a unimodal approach for prognostication within 72 hours from ROSC, based on status myoclonus (SM) within 24 hours, SSEP, or NSE at 24 to 72 hours and ocular reflexes or M ≤ 2 at 72 hours. The 2015 guidelines from the European Resuscitation Council and the European Society of Intensive Care Medicine suggest a multimodal prognostication algorithm, to be used in both TTM-treated and non-TTM-treated patients with M ≤ 2 at ≥ 72 hours from ROSC. Ocular reflexes (pupillary and corneal) and SSEPs should be used first, followed by a combination of other predictors (SM, EEG, NSE, imaging) if results of the first predictors are normal

Management of oxygen and carbon dioxide pressure after cardiac arrest.

Experimental evidence shows that derangements of arterial partial pressures of either oxygen (PaO2) and carbon dioxide (PaCO2) immediately after resuscitation from cardiac arrest may increase the severity of organ dysfunction due to whole body ischemia and subsequent reperfusion. Hyperoxia is believed to increase reperfusion injury, especially to mitochondrial membrane due to increased production of reactive oxygen species. Two large observational studies in human adults showed that hyperoxia (defined as a PaO2 65300 mmHg) in the first 24h after hospital admission was associated with increased mortality or lower likelihood of independent functional status at hospital discharge. Evidence of the effects of hyperoxia in children were less consistent. A reduction of PaCO2 below normal values may cause cerebral vasoconstriction and increase the severity of delayed brain hypopefusion which usually occurs within 24h from resuscitation. Cerebrovascular reactivity to CO2 is preserved during therapeutic hypothermia. According to recent clinical studies, a low PaCO2 after resuscitation is associated with increased mortality and higher rates of poor neurological outcome both in children and in adults, while the effects of a PaCO2 above 45 mmHg are less clear. The PaCO2 derangements are very common in resuscitated patients. Maintaining normal levels of both PaO2 and PaCO2 and in particular avoiding both hyperoxia and hypocapnia may reduce morbidity and improve survival of cardiac arrest survivors. Available clinical evidence is however almost exclusively limited to observational studies which may be biased by potential uncontrolled confounders

Prediction of poor neurological outcome within 24\u202fh from cardiac arrest: Can electrophysiology-based indices be helpful?

The vast majority of patients who are resuscitated from out of hospital cardiac arrest (CA) are unconscious during the first 24 h after return of spontaneous circulation (ROSC), as a result of hypoxic-ischaemic brain injury (HIBI). Two-thirds of these patients die before hospital discharge, mainly because of active withdrawal of life-sustaining treatment (WLST) based on prediction of a poor neurological outcome. In order to avoid an inappropriate WLST, prognostication after CA should be as accurate as possible. According to the 2015 ERC-ESICM Guidelines on Post-Resuscitation Care a poor neurological outcome can be predicted with high certainty (false positive rate [FPR] < 5%, narrow confidence interval) based on the bilateral absence of pupillary and corneal reflexes or the N20 wave of short-latency somatosensory evoked potentials (SSEPs) after 72 h or more from ROSC. However, recent evidence shows that an accurate prediction before this time point, namely within 24h from ROSC is feasible, based on electrophysiological indices. In this paper recent evidence on EEG-based predictors, classified according to the 2013 guidelines of the American Clinical Neurophysiology Society (ACNS) is presented and discussed

Critically ill children with Down Syndrome: The associated risk for cardiac arrest and mortality

Down Syndrome (DS) represents one of the most common chromosomal abnormalities in humans, occurring in one per 691 babies born in the United States, equivalent to about 6000 each year. Congenital heart diseases are commonand may represent a risk factor for early death in children with DS. However, little data are available on the epidemiology of cardiac arrest (CA ) in this category of patients and on its relevant outcome as compared to that of children with no genetic disease. Recent data show that the prevalence of CA in DS-patients admitted to intensive care unit is very similar to that observed in non-DS patients (2-3%), and that its outcome is relatively faviourable. This can be attributed to the high prevalence of cardiac causes, especially arrhythmias

Capnography during cardiac arrest

Successful resuscitation from cardiac arrest depends on provision of adequate blood flow to vital organs generated by cardiopulmonary resuscitation (CPR). Measurement of end-tidal expiratory pressure of carbon dioxide (ETCO2) using capnography provides a noninvasive estimate of cardiac output and organ perfusion during cardiac arrest and can therefore be used to monitor the quality of CPR and predict return of spontaneous circulation (ROSC). In clinical observational studies, mean ETCO2 levels in patients with ROSC are higher than those in patients with no ROSC. In prolonged out of hospital cardiac arrest, ETCO2 levels <10 mmHg are consistently associated with a poor outcome, while levels above this threshold have been suggested as a criterion for considering patients for rescue extracorporeal resuscitation. An abrupt rise of ETCO2 during CPR suggests that ROSC has occurred. Finally, detection of CO2 in exhaled air following intubation is the most specific criterion for confirming endotracheal tube placement during CPR. The aetiology of cardiac arrest, variations in ventilation patterns during CPR, and the effects of drugs such as adrenaline or sodium bicarbonate administered as a bolus may significantly affect ETCO2 levels and its clinical significance. While identifying ETCO2 as a useful monitoring tool during resuscitation, current guidelines for advanced life support recommend against using ETCO2 values in isolation for decision making in cardiac arrestmanagement

Risk of intracranial bleeding in patients with primary brain cancer receiving therapeutic anticoagulation for venous thromboembolism: A meta-analysis

Venous thromboembolism (VTE) is common in glioma patients. Also, spontaneous intracerebral hemorrhage (ICH) is frequently observed in subjects with primary brain tumors. Thus, the management of anticoagulant therapy for VTE is challenging and controversial in these patients. We performed a meta-analysis to clarify the risk of ICH in glioma patients treated with anticoagulant therapy for VTE compared to glioma patients without VTE

Predictors of favourable outcome after in-hospital cardiac arrest treated with extracorporeal cardiopulmonary resuscitation: A systematic review and meta-analysis

Aims To identify the predictors of survival to discharge in adults resuscitated with extracorporeal cardiopulmonary resuscitation (ECPR) following in-hospital cardiac arrest (IHCA). Methods MEDLINE and ISI Web of Science were searched for eligible studies. Pooled Odds Ratio (OR) and Pooled Mean Difference (PMD) for each predictor were calculated. The quality of evidence (QOE) was evaluated according to the GRADE guidelines. Results Eleven studies were included totalling 856 patients. Of these, 324 (37.9%) survived to discharge. Good neurological outcome (Cerebral Performance Category 1 or 2) occurred in 222/263 (84.4%) survivors. Survival was associated with significantly higher odds of an initial shockable rhythm (OR 1.65; 95% confidence interval [95%CI] 1.05\ue2\u80\u932.61; p = 0.03), shorter low-flow time (PMD \ue2\u88\u9217.15 [\ue2\u88\u9220.90, \ue2\u88\u9213.40] min; p < 0.00001), lower lactate levels both immediately before ECPR start (PMD \ue2\u88\u924.12 [\ue2\u88\u926.0,\ue2\u88\u922.24] mmol/L; p < 0.0001) and on ICU admission (PMD \ue2\u88\u924.13 [\ue2\u88\u926.38, \ue2\u88\u921.88] mmol/L; p < 0.0003), lower SOFA score (PMD \ue2\u88\u921.71 [\ue2\u88\u922.93, \ue2\u88\u920.50]; p = 0.006) and lower creatinine levels within 24 h after ICU admission (PMD \ue2\u88\u920.37 [\ue2\u88\u920.54, \ue2\u88\u920.19] mg/dl; p < 0.00001). No significant association was found between survival and age, gender, or cardiac vs. non-cardiac aetiology. The overall QOE was low or very low. Conclusions In adult IHCA treated with ECPR a shockable initial rhythm, a lower low-flow time, lower blood lactate levels before ECPR start or on ICU admission, and a lower SOFA score or creatinine levels in the first 24 h after ICU admission were associated with a higher likelihood of survival. These factors could help identifying patients who are eligible for ECPR

The ISHTAR mission: Probing the interior of asteroids

ISHTAR (Internal Structure High-resolution Tomography by Asteroid Rendezvous) is a mission developed in response to ESA's recent call for ideas for Near Earth Object (NEO) exploration and discovery. The study, led by Astrium in cooperation with several scientific institutes throughout Europe, has produced a low-cost spacecraft design capable of performing multiple asteroid rendezvous and to characterize them with a focussed set of instruments. The ISHTAR concept is centred around a Radar Tomography payload .able to probe the internal structure of a small asteroid to depths of 300-1000m. This instrument uses low-frequency radio waves that can penetrate deep inside solid rock and records the reflected echoes caused by changes in the internal structure (permittivity). By combining these signals in a coherent fashion, it is possible to reconstruct a 3D image of the asteroid interior. The radar payload combined with a multispectral imager for measurement of the surface properties & surface geology, an IR spectrometer for mineralogical characterization, and a radio science experiment for accurate mass, mass distribution and density determination. The ISHTAR mission is designed to visit at least 2 NEOs, ideally one stony and one carbonaceous in composition, as these types are the most common among the NEO population. This unique combination of instruments and multiple rendezvous will allow the first detailed physical characterization of the NEO population and represents an essential step towards the development of mitigation strategies to protect the Earth from impact