Assessing prognosis following cardiopulmonary resuscitation and therapeutic hypothermia-a critical discussion of recent studies

[Palliative aspects in clinical acute and emergency medicine as well as intensive care medicine : Consensus paper of the DGIIN, DGK, DGP, DGHO, DGfN, DGNI, DGG, DGAI, DGINA and DG Palliativmedizin]

The integration of palliative medicine is an important component in the treatment of various advanced diseases. While a German S3 guideline on palliative medicine exists for patients with incurable cancer, a recommendation for non-oncological patients and especially for palliative patients presenting in the emergency department or intensive care unit is missing to date. Based on the present consensus paper, the palliative care aspects of the respective medical disciplines are addressed. The timely integration of palliative care aims to improve quality of life and symptom control in clinical acute and emergency medicine as well as intensive care.

The effects of ECMO on neurological function recovery of critical patients: A double-edged sword

Extracorporeal membrane oxygenation (ECMO) played an important role in the treatment of patients with critical care such as cardiac arrest (CA) and acute respiratory distress syndrome. ECMO is gradually showing its advantages in terms of speed and effectiveness of circulatory support, as it provides adequate cerebral blood flow (CBF) to the patient and ensures the perfusion of organs. ECMO enhances patient survival and improves their neurological prognosis. However, ECMO-related brain complications are also important because of the high risk of death and the associated poor outcomes. We summarized the reported complications related to ECMO for patients with CA, such as north–south syndrome, hypoxic–ischemic brain injury, cerebral ischemia–reperfusion injury, impaired intracranial vascular autoregulation, embolic stroke, intracranial hemorrhage, and brain death. The exact mechanism of ECMO on the role of brain function is unclear. Here we review the pathophysiological mechanisms associated with ECMO in the protection of neurologic function in recent years, as well as the ECMO-related complications in brain and the means to improve it, to provide ideas for the treatment of brain function protection in CA patients.

Reliability of prognostic biomarkers after prehospital extracorporeal cardiopulmonary resuscitation with target temperature management

BACKGROUND

Extracorporeal cardiopulmonary resuscitation (ECPR) performed at the emergency scene in out-of-hospital cardiac arrest (OHCA) can minimize low-flow time. Target temperature management (TTM) after cardiac arrest can improve neurological outcome. A combination of ECPR and TTM, both implemented as soon as possible on scene, appears to have promising results in OHCA. To date, it is still unknown whether the implementation of TTM and ECPR on scene affects the time course and value of neurological biomarkers.

METHODS

69 ECPR patients were examined in this study. Blood samples were collected between 1 and 72 h after ECPR and analyzed for S100, neuron-specific enolase (NSE), lactate, D-dimers and interleukin 6 (IL6). Cerebral performance category (CPC) scores were used to assess neurological outcome after ECPR upon hospital discharge. Resuscitation data were extracted from the Regensburg extracorporeal membrane oxygenation database and all data were analyzed by a statistician. The data were analyzed using non-parametric methods. Diagnostic accuracy of biomarkers was determined by area under the curve (AUC) analysis. Results were compared to the relevant literature.

RESULTS

Non-hypoxic origin of cardiac arrest, manual chest compression until ECPR, a short low-flow time until ECPR initiation, low body mass index (BMI) and only a minimal need of extra-corporeal membrane oxygenation support were associated with a good neurological outcome after ECPR. Survivors with good neurological outcome had significantly lower lactate, IL6, D-dimer, and NSE values and demonstrated a rapid decrease in the initial S100 value compared to non-survivors.

CONCLUSIONS

A short low-flow time until ECPR initiation is important for a good neurological outcome. Hypoxia-induced cardiac arrest has a high mortality rate even when ECPR and TTM are performed at the emergency scene. ECPR patients with a higher BMI had a worse neurological outcome than patients with a normal BMI. The prognostic biomarkers S100, NSE, lactate, D-dimers and IL6 were reliable indicators of neurological outcome when ECPR and TTM were performed at the emergency scene.

[Influence of therapeutic temperature management on the clinical course in patients after in-hospital cardiac arrest : A retrospective analysis]

METHODS

Retrospective analysis of all patients with in-hospital cardiac arrest and return of spontaneous circulation (ROSC) in the ICU of the cardiologic department of the University Hospital of Halle (Saale) between 1999 and 2009.

RESULTS

During the observation period, 169 patients with in-hospital cardiac arrest and information regarding temperature measurements were treated. Invasive therapeutic temperature management (TTM+) was applied in 64 patients (37.9%), while 105 patients (62.1%) underwent no therapeutic temperature management (TTM-). TTM+ and TTM- showed no relevant differences regarding patient age (TTM+: 67.6 ± 12.6 years; TTM-: 69.8 ± 12.6 years; p = 0.257), comorbidities and the initial rhythm; however, there were more men in the TTM+ group (76.6% vs. 58.1%; p = 0.015). All patients had been intubated. Time until ROSC in TTM+ was significantly longer (25.9 ± 25.8 min vs. 15.0 ± 12.4 min; p < 0.005). TTM+ resulted in a lower 30-day survival and an unfavourable neurologic outcome (Glasgow outcome scale I or II: 75% TTM+ vs. 55.2% TTM-). This negative effect persisted after adjustment for age of the patients, but not after adjustment for age and duration of reanimation (nonadjusted odds ratio for adverse neurologic outcome under TTM+: 0.411 (p = 0.011); odds ratio after adjusting for age: 0.361 (p = 0.09); odds ratio after adjusting for age and duration of the reanimation: 0.505 (p = 0.121)).

The Use of Continuous EEG Monitoring in Intensive Care Units in The Netherlands: A National Survey

Background

Currently, continuous electroencephalographic monitoring (cEEG) is the only available diagnostic tool for continuous monitoring of brain function in intensive care unit (ICU) patients. Yet, the exact relevance of routinely applied ICU cEEG remains unclear, and information on the implementation of cEEG, especially in Europe, is scarce. This study explores current practices of cEEG in adult Dutch ICU departments focusing on organizational and operational factors, development over time and factors perceived relevant for abstaining its use.

Methods

A national survey on cEEG in adults among the neurology and adult intensive care departments of all Dutch hospitals (n = 82) was performed.

Results

The overall institutional response rate was 78%. ICU cEEG is increasingly used in the Netherlands (in 37% of all hospitals in 2016 versus in 21% in 2008). Currently in 88% of university, 55% of teaching and 14% of general hospitals use ICU cEEG. Reasons for not performing cEEG are diverse, including perceived non-feasibility and lack of data on the effect of cEEG use on patient outcome. Mostly, ICU cEEG is used for non-convulsive seizures or status epilepticus and prognostication. However, cEEG is never or rarely used for monitoring cerebral ischemia and raised intracranial pressure in traumatic brain injury. Review and reporting practices differ considerably between hospitals. Nearly all hospitals perform non-continuous review of cEEG traces. Methods for moving toward continuous review of cEEG traces are available but infrequently used in practice.

Conclusions

cEEG is increasingly used in Dutch ICUs. However, cEEG practices vastly differ between hospitals. Future research should focus on uniform cEEG practices including unambiguous EEG interpretation to facilitate collaborative research on cEEG, aiming to provide improved standard patient care and robust data on the impact of cEEG use on patient outcome.

[Therapy escalation for the potential organ donor : Are all intensive care measures also ethically justifiable?]

The gap between the number of organs needed and the number available has dramatically increased in Germany in the last decade-for intensivists and transplantation specialists, it is challenging to cover the demand responsibly. It is therefore increasingly important to identify potential organ donors in order to realize organ donation. An escalation of intensive care measures is often required, which raises critical ethical questions. In Germany, organ donation is only allowed after brain death with prior informed consent from the deceased or his/her relatives. Determining the willingness of the potential organ donor and adapting the subsequent intensive care to it requires experience and empathy. Therapy escalation for the realization of organ donation is not opposed to the basic ethical principles of medicine, but remains an individual decision. A time limitation of this last intensive therapy phase to achieve optimal conditions for transplantation should be discussed with the relatives and adapted to the medical requirements. This article would like to highlight ethical questions that are relevant in the context of therapy escalation of potential organ donors and, thus, support the decision-making process.

History and current use of mild therapeutic hypothermia after cardiac arrest

In spite of many years of development and implementation of pre-hospital advanced life support programmes, the survival rate of out-of-hospital cardiac arrest (OHCA) used to be very poor. Neurologic injury from cerebral hypoxia is the most common cause of death in patients with OHCA. In the past two decades, post-resuscitation care has developed many new concepts aimed at improving the neurological outcome and survival rate of patients after cardiac arrest. Systematic post-cardiac arrest care after the return of spontaneous circulation, including induced mild therapeutic hypothermia (TH) in selected patients, is aimed at significantly improving rates of long-term neurologically intact survival. This review summarises the history and current knowledge in the field of mild TH after OHCA.

Electrophysiological Monitoring of Brain Injury and Recovery after Cardiac Arrest

Reliable prognostic methods for cerebral functional outcome of post cardiac-arrest (CA) patients are necessary, especially since therapeutic hypothermia (TH) as a standard treatment. Traditional neurophysiological prognostic indicators, such as clinical examination and chemical biomarkers, may result in indecisive outcome predictions and do not directly reflect neuronal activity, though they have remained the mainstay of clinical prognosis. The most recent advances in electrophysiological methods--electroencephalography (EEG) pattern, evoked potential (EP) and cellular electrophysiological measurement--were developed to complement these deficiencies, and will be examined in this review article. EEG pattern (reactivity and continuity) provides real-time and accurate information for early-stage (particularly in the first 24 h) hypoxic-ischemic (HI) brain injury patients with high sensitivity. However, the signal is easily affected by external stimuli, thus the measurements of EP should be combined with EEG background to validate the predicted neurologic functional result. Cellular electrophysiology, such as multi-unit activity (MUA) and local field potentials (LFP), has strong potential for improving prognostication and therapy by offering additional neurophysiologic information to understand the underlying mechanisms of therapeutic methods. Electrophysiology provides reliable and precise prognostication on both global and cellular levels secondary to cerebral injury in cardiac arrest patients treated with TH.

Early prognostication markers in cardiac arrest patients treated with hypothermia

BACKGROUND AND PURPOSE

Established prognostication markers, such as clinical findings, electroencephalography (EEG) and biochemical markers, used by clinicians to predict neurological outcome after cardiac arrest (CA) are altered under therapeutic hypothermia (TH) conditions and their validity remains uncertain.

METHODS

MEDLINE and Embase were searched for evidence on the current standards for neurological outcome prediction for out-of-hospital CA patients treated with TH and the validity of a wide range of prognostication markers. Relevant studies that suggested one or several established biomarkers and multimodal approaches for prognostication are included and reviewed.

RESULTS

Whilst the prognostic accuracy of various tests after TH has been questioned, pupillary light reflexes and somatosensory evoked potentials are still strongly associated with negative outcome for early prognostication. Increasingly, EEG background activity has also been identified as a valid predictor for outcome after 72 h after CA and a preferred prognostic method in clinical settings. Neuroimaging techniques, such as magnetic resonance imaging and computed tomography, can identify functional and structural brain injury but are not readily available at the patient's bedside because of limited availability and high costs.

CONCLUSIONS

A multimodal algorithm composed of neurological examination, EEG-based quantitative testing and somatosensory evoked potentials, in conjunction with newer magnetic resonance imaging sequences, if available, holds promise for accurate prognostication in CA patients treated with TH. In order to avoid premature withdrawal of care, prognostication should be performed more than 72 h after CA.

Persistent vegetative state and minimally conscious state: a systematic review and meta-analysis of diagnostic procedures

BACKGROUND

Acute brain damage can cause major disturbances of consciousness, ranging all the way to the persistent vegetative state (PVS), which is also known as "unresponsive wakefulness syndrome". PVS can be hard to distinguish from a state of minimal preserved consciousness ("minimally conscious state," MCS); the rate of misdiagnosis is high and has been estimated at 37-43%. In contrast, PVS is easily distinguished from brain death. We discuss the various diagnostic techniques that can be used to determine whether a patient is minimally conscious or in a persistent vegetative state.

METHODS

This article is based on a systematic review of pertinent literature and on a quantitative meta-analysis of the sensitivity and specificity of new diagnostic methods for the minimally conscious state.

RESULTS

We identified and evaluated 20 clinical studies involving a total of 906 patients with either PVS or MCS. The reported sensitivities and specificities of the various techniques used to diagnose MCS vary widely. The sensitivity and specificity of functional MRI-based techniques are 44% and 67%, respectively (with corresponding 95% confidence intervals of 19%-72% and 55%-77%); those of quantitative EEG are 90% and 80%, respectively (95% CI, 69%-97% and 66%-90%). EEG, event-related potentials, and imaging studies can also aid in prognostication. Contrary to prior assumptions, 10% to 24% of patients in PVS can regain consciousness, sometimes years after the event, but only with marked functional impairment.

CONCLUSION

The basic diagnostic evaluation for differentiating PVS from MCS consists of a standardized clinical examination. In the future, modern diagnostic techniques may help identify patients who are in a subclinical minimally conscious state.

["Bridge to recovery"- implantation of an Impella® CP in infarct-related cardiogenic shock]

We present the case of a 43-year-old man with the diagnosis of a posterior and anterior wall infarction who was taken to our institution after prolonged cardioplumonary resuscitation. Cardiac catheterization showed thrombotic occlusion of the LAD and a subtotal stenosis of the right coronary artery. Both lesions were revascularized by PCI. Despite catecholamine infusion, the patient developed severe cardiogenic shock with multiorgan dysfunction syndrome under therapeutic hypothermia. Thus, an Impella® CP, a percutaneous left ventricular assist device (LVAD), was implanted. Due to effective LVAD support, it was possible to wean and remove the device after 75 h of support. The impaired left ventricular ejection fraction and wall-motion abnormalities which were present on day 1 achieved complete recuperation on day 14. The patient was discharged without any neurological deficits.

Management of patients with risk factors

This review addresses concomitant diseases and risk factors in patients treated for diseases of the ears, nose and throat in outpatient and hospital services. Besides heart disease, lung disease, liver disease and kidney disease, this article also covers disorders of coagulation (including therapy with new oral anticoagulants) and electrolyte imbalance. Special attention is paid to the prophylaxis, diagnosis and treatment of perioperative delirium. It is also intended to help optimise the preparation for surgical procedures and pharmacotherapy during the hospital stay.