Predictors of awakening from postanoxic status epilepticus after therapeutic hypothermia

Ongoing abdominal status myoclonus in postanoxic coma

We present the video of a patient who presented massive and ongoing rhythmic abdominal myoclonus in postanoxic coma.

Frequency and timing of nonconvulsive status epilepticus in comatose post-cardiac arrest subjects treated with hypothermia

BACKGROUND

Therapeutic hypothermia (TH) improves outcomes in comatose patients resuscitated from cardiac arrest. However, nonconvulsive status epilepticus (NCSE) may cause persistent coma. The frequency and timing of NCSE after cardiac arrest is unknown.

METHODS

Review of consecutive subjects treated with TH and receiving continuous EEG (cEEG) monitoring between 8/1/2009 and 11/16/2010. Demographic data, survival, and functional outcome were prospectively recorded. Each cEEG file was analyzed using standard definitions to define NCSE. Data were analyzed using descriptive and nonparametric statistics.

RESULTS

Mean age of the 101 subjects was 57 years (SD 15) with most subjects being male (N = 55, 54%) and experiencing out-of-hospital cardiac arrest (N = 78; 77%). Ventricular fibrillation was the initial cardiac rhythm in 39 (38%). All subjects received TH. Thirty subjects (30%) awoke at a median of 41 h (IQR 30, 61) after cardiac arrest. A total of 29/30 (97%) subjects surviving to hospital discharge were awake. Median interval from arrest to placement of cEEG was 9 h (IQR 6, 12), at which time the mean temperature was 33.9°C. NCSE occurred in 12 (12%) subjects. In 3/12 (25%) subjects, NCSE was present when the cEEG recording began. In 4 subjects, NCSE occurred within 8 h of cEEG recording. One (8%) subject with NCSE survived in a vegetative state.

CONCLUSIONS

NCSE is common in comatose post-cardiac arrest subjects receiving TH. Most seizures occur within the first 8 h of cEEG recording and within the first 12 h after resuscitation from cardiac arrest. Outcomes are poor in those who experience NCSE.

Effect of mild hypothermia on glutamate receptor expression after status epilepticus

Hypothermia has been shown to have neuroprotective effects in various models of neurological damage. However, its therapeutic effect on pediatric status epilepticus (SE) is still unknown. We conducted a study to investigate whether hypothermia can have an adjuvant effect on pilocarpine-induced status epilepticus in immature rats when combined with diazepam treatment. Pilocarpine-induced status epilepticus was maintained for either 30 min or 60 min, which was followed by injection with diazepam (10mg/kg body weight) and/or treatment with mild hypothermia (core temperature to 33°C). We found that the spike-wave amplitude and frequency after SE during treatment with diazepam and hypothermia was significantly lower than treatment with diazepam alone. Mild hypothermia significantly reduced the number of cells undergoing necrosis and apoptosis. In addition, α-amino-3-hydroxyl-5-methyl-4-isoxazole-propionate (AMPA) receptor subunit GluR1 was shown to be up-regulated by SE, while GluR2 was shown to be down-regulated. However, after combination therapy with diazepam and mild hypothermia for 8h, the expression of GluR1 was decreased and GluR2 was increased relative to the levels of diazepam alone treated juveniles. We also found that the expression of mGluR-1a was also decreased relative to diazepam alone. These findings suggest that mild hypothermia might further protect against pilocarpine-induced status epilepticus in immature rats by regulating glutamate receptor expression. This study was conducted using a pediatric model of SE so as to gain a better understanding of the role of hypothermia in the developing brain.

The frequency and timing of epileptiform activity on continuous electroencephalogram in comatose post-cardiac arrest syndrome patients treated with therapeutic hypothermia

AIM

The incidence and timing of electrographic seizures and epileptiform activity in comatose, adult, post-cardiac arrest syndrome (PCAS) patients treated with therapeutic hypothermia (TH) have not been extensively investigated. We hypothesized that onset most frequently occurs within the first 24 h post-arrest and is associated with poor neurologic outcome.

METHODS

Single-center, retrospective analysis of a cohort of 38 comatose PCAS patients treated with TH and continuous-EEG-monitoring (cEEG), initiated as soon as possible after ICU admission. All raw cEEG waveform records were cleared of annotations and clinical information and classified by two fellowship-trained electroencephalographers.

RESULTS

Twenty-three percent (9/38) of patients had electrographic seizures (median onset 19 h post-arrest); 5/9 (56%) had seizure-onset prior to rewarming; 7/9 (78%) had status epilepticus. Forty-five percent (17/38) had evidence of epileptiform activity (electrographic seizures or interictal epileptiform discharges), typically occurring during first 24 h post-arrest. Interictal epileptiform activity was highly associated with later detection of electrographic seizures (6/14, 43%, p=0.001). Ninety-four percent (16/17) of patients with epileptiform activity had poor neurologic outcome or death at discharge (Cerebral Performance Category scale 3-5; p=0.002) as did all (9/9) patients with electrographic seizures (p=0.034).

CONCLUSIONS

Electrographic seizures and epileptiform activity are common cEEG findings in comatose, PCAS patients treated with TH. In this preliminary study, most seizures were status epilepticus, had onset prior to rewarming, evolved from prior interictal epileptiform activity, and were associated with short-term mortality and poor neurologic outcome. Larger, prospective studies are needed to further characterize seizure activity in comatose post-arrest patients.

Outcome from therapeutic hypothermia and EEG

PURPOSE

The aim of this study is to characterize the significance of EEG findings during therapeutic hypothermia.

METHODS

The authors retrospectively reviewed continuous EEG monitoring data of every patient treated with therapeutic hypothermia after cardiac arrest from January 2008 to December 2009. EEG data were correlated with a functional outcome at the time of discharge.

RESULTS

Data from 26 patients (14 men and 12 women) were reviewed. All the patients were treated with therapeutic hypothermia. The mean age was 60.3 years. The initial EEG background was severely depressed in 13 patients, suppression-burst pattern was present in 4 patients, alpha or theta coma pattern was present in 2 patients, generalized slow-wave activity was present in 3 patients, and generalized periodic epileptiform discharges were present in 4 patients. Epileptiform activity was present in 10 patients (38.5%). Initial background activity with generalized slow-wave activity correlated with better prognosis compared with other types of background activity (P = 0.017).

CONCLUSIONS

The majority of patients (20 of 26) had poor outcomes despite therapeutic hypothermia. Continuous EEG background with generalized slow-wave activity correlated with survival and better prognosis in this study.

The utility of EEG, SSEP, and other neurophysiologic tools to guide neurocritical care

Neuromonitoring is an emerging field that aims to characterize real-time neurophysiology to tailor therapy for acute injuries of the central nervous system. While cardiac telemetry has been used for decades among patients requiring critical care of all kinds, neurophysiology and neurotelemetry has only recently emerged as a routine screening tool in comatose patients. The increasing utilization of electroencephalography in comatose patients is primarily due to the recognition of the common occurrence of nonconvulsive seizures among comatose patients, the development of quantitative measures to detect regional ischemia, and the appreciation of electroencephalography phenotypes that indicate prognosis after cardiac arrest. Other neuromonitoring tools, such as somatosensory evoked potentials have a complementary role, surveying the integrity of the neuroaxis as an indicator of prognosis or illness progression in both acute brain and spinal injuries.

What is the value of hypothermia in acute neurologic diseases and status epilepticus?

Patients with status epilepticus that proves refractory to anesthetic agents represent a daunting challenge for treating clinicians. Animal data support the neuroprotective action of brain hypothermia, and its efficacy in status epilepticus models. This approach, targeting a core temperature of about 33°C for at least 24 hours together with pharmacological sedation, has been described in adults and children. However, although relatively safe if concomitant barbiturates are avoided, it seems that mild hypothermia rarely allows a sustained control of ongoing status epilepticus, since seizures tend to recur in normothermia. Conversely, mild hypothermia has a high-evidence level and is increasingly used in postanoxic encephalopathy, both in newborns and adults. Due to the paucity of available clinical data, prospective studies are needed to assess the value of hypothermia in status epilepticus.

Management of refractory status epilepticus in adults: still more questions than answers

Refractory status epilepticus (RSE) is defined as status epilepticus that continues despite treatment with benzodiazepines and one antiepileptic drug. RSE should be treated promptly to prevent morbidity and mortality; however, scarce evidence is available to support the choice of specific treatments. Major independent outcome predictors are age (not modifiable) and cause (which should be actively targeted). Recent recommendations for adults suggest that the aggressiveness of treatment for RSE should be tailored to the clinical situation. To minimise intensive care unit-related complications, focal RSE without impairment of consciousness might initially be approached conservatively; conversely, early induction of pharmacological coma is advisable in generalised convulsive forms of the disorder. At this stage, midazolam, propofol, or barbiturates are the most commonly used drugs. Several other treatments, such as additional anaesthetics, other antiepileptic or immunomodulatory compounds, or non-pharmacological approaches (eg, electroconvulsive treatment or hypothermia), have been used in protracted RSE. Treatment lasting weeks or months can sometimes result in a good outcome, as in selected patients after encephalitis or autoimmune disorders. Well designed prospective studies of RSE are urgently needed.

Difficulties with neurological prognostication in a young woman with delayed-onset generalised status myoclonus after cardiac arrest due to acute severe asthma

Neurological prognostication in cardiac arrest survivors is difficult, especially when the primary etiology is respiratory arrest. Prognostic factors designed to have zero false-positive rates to robustly confirm poor outcome are usually inadequate to rule out poor outcomes (i.e., high specificity and low sensitivity). One of the least understood prognosticators is generalised status myoclonus (GSM), with case reports confusing GSM, isolated myoclonic jerks and post-hypoxic intention myoclonus (Lance Adams syndrome [LAS]). With several prognostic indicators (including status myoclonus) having been validated in the pre-hypothermia era, their current relevance is debatable. New modalities such as brain magnetic resonance imaging (MRI) and continuous electroencephalography are being evaluated. We describe here a pregnant woman resuscitated from a cardiac arrest due to acute severe asthma, and an inability to reach a consensus based on published guidelines, with a brief overview of myoclonus, LAS and the role of MRI brain in assisting prognostication.

Survivors and nonsurvivors of very prolonged status epilepticus

Several studies have shown reliable predictive factors for outcome in status epilepticus (SE), especially etiology and presentation in coma. Duration of SE is predictive, but probably only in the first few hours, and there have been many reports of patients treated successfully for SE lasting many days or weeks. Nevertheless, there are many other patients with SE treated for prolonged periods without success, sometimes apparently futilely. We compared clinical features of 10 survivors of prolonged SE with those of a matched cohort treated for similarly prolonged episodes but unsuccessfully, looking for exceptions to known predictive factors. Multiple medical problems (i.e., etiologies) and coma on presentation were confirmed as predictors of a poor outcome. Analysis of individual exceptions to these predictors showed that age, overall background health, and family input on the value of prolonged treatment, on the one hand, and earlier epilepsy plus rapid and accurate diagnosis and treatment, on the other, contributed to results different from what would have been expected.

Neurologic recovery after therapeutic hypothermia in patients with post-cardiac arrest myoclonus

Early myoclonus in comatose survivors of cardiac arrest, even when it is not myoclonic status epilepticus (MSE), is considered a sign of severe global brain ischemia and has been associated with high rates of mortality and poor neurologic outcomes. We report on three survivors of primary circulatory cardiac arrests who had good neurologic outcomes (two patients with a CPC score=1 and one patient with a CPC score=2) after mild therapeutic hypothermia, despite exhibiting massive myoclonus within the first 4h after return of spontaneous circulation. The concept that early myoclonus heralds a uniformly poor prognosis may need to be reconsidered in the era of post-cardiac arrest mild therapeutic hypothermia.

Predicting neurological outcome after cardiac arrest

PURPOSE OF REVIEW

Therapeutic hypothermia and aggressive management of postresuscitation disease considerably improved outcome after adult cardiac arrest over the past decade. However, therapeutic hypothermia alters prognostic accuracy. Parameters for outcome prediction, validated by the American Academy of Neurology before the introduction of therapeutic hypothermia, need further update.

RECENT FINDINGS

Therapeutic hypothermia delays the recovery of motor responses and may render clinical evaluation unreliable. Additional modalities are required to predict prognosis after cardiac arrest and therapeutic hypothermia. Electroencephalography (EEG) can be performed during therapeutic hypothermia or shortly thereafter; continuous/reactive EEG background strongly predicts good recovery from cardiac arrest. On the contrary, unreactive/spontaneous burst-suppression EEG pattern, together with absent N20 on somatosensory evoked potentials (SSEP), is almost 100% predictive of irreversible coma. Therapeutic hypothermia alters the predictive value of serum markers of brain injury [neuron-specific enolase (NSE), S-100B]. Good recovery can occur despite NSE levels >33 μg/l, thus this cut-off value should not be used to guide therapy. Diffusion MRI may help predicting long-term neurological sequelae of hypoxic-ischemic encephalopathy.

SUMMARY

Awakening from postanoxic coma is increasingly observed, despite early absence of motor signs and frank elevation of serum markers of brain injury. A new multimodal approach to prognostication is therefore required, which may particularly improve early prediction of favorable clinical evolution after cardiac arrest.

Post-cardiac arrest syndrome: update on brain injury management and prognostication

OPINION STATEMENT

Treatment of cardiac arrest should focus on maximizing neurologic recovery as well as systemic recovery to ensure the best possible functional outcome. This article focuses on the neurologic care of patients after they have been resuscitated from cardiac arrest. Maximizing neurologic outcome after cardiac arrest requires attention to prevention of primary and secondary brain injury. Primary brain injury such as hypoperfusion and hypoxic injury should be avoided by optimizing hemodynamic goals to maximize cerebral perfusion and maintain normoxia and normocarbia. Secondary brain injury mediated by excitotoxicity and the inflammatory cascade may be mitigated by therapeutic hypothermia. Other strategies that may be beneficial include the treatment of seizures and maintaining normoglycemia. Finally, accurate and timely prognostication is crucial because it influences withdrawal of care and overall mortality. With the adoption of therapeutic hypothermia, the classic prognostic paradigm that was previously used needs to be reexamined. The application of our knowledge of risk factors for poor outcome, serial physical examinations, neurophysiological tests, neuroimaging, and biochemical markers may need to be delayed until after rewarming. We emphasize the importance of a shift in physicians' approach to the management of post-cardiac arrest syndrome, not only in prognostication, but also in the early and aggressive therapies that have been shown to improve survival and quality of life.

Early EEG monitoring for detecting postanoxic status epilepticus during therapeutic hypothermia: a pilot study

OBJECTIVE

To determine whether routine electroencephalography (EEG) detected electrical status epilepticus (ESE), masked by neuromuscular blockade, in comatose cardiac-arrest survivors receiving therapeutic hypothermia.

DESIGN

Prospective 3-year study.

SETTING

Medical ICU.

PATIENTS

Fifty-one consecutive comatose cardiac-arrest patients treated between May 2005 and May 2008 using a standardized protocol of hypothermia with neuromuscular blockade.

INTERVENTION

EEG was performed routinely as soon as possible after starting therapeutic hypothermia. EEG recordings were read by an independent neurophysiologist who was blinded to patient data.

MEASUREMENTS AND MAIN RESULTS

Median body temperature at EEG recording was 33.0°C (range 32.4-33.8). ESE was found on 5 (10%) of the 51 EEG recordings: three patients had continuous rhythmic generalized spikes and two patients had continuous rhythmic focal spike-waves. Of the 17 (33%) patients who were discharged alive, 8 (8/51, 16%) had a CPC score of 1, 4 (8%) of 2, and 5 (10%) of 3. All patients with ESE died during their ICU stay.

CONCLUSION

These preliminary results indicate that postanoxic status epilepticus can be masked by neuromuscular blockade during our protocol of therapeutic hypothermia. Routine EEG monitoring might be helpful in cardiac-arrest survivors receiving therapeutic hypothermia. Further studies including continuous EEG monitoring are needed to determine whether early diagnosis and treatment of ESE during therapeutic hypothermia improves the outcome.

Short-term outcome prediction by electroencephalographic features in children treated with therapeutic hypothermia after cardiac arrest

BACKGROUND

Electroencephalographic (EEG) features may provide objective data regarding prognosis in children resuscitated from cardiac arrest (CA), but therapeutic hypothermia (TH) may impact its predictive value. We aimed to determine whether specific EEG features were predictive of short-term outcome in children treated with TH after CA, both during hypothermia and after return to normothermia.

METHODS

Thirty-five children managed with a standard clinical TH algorithm after CA were prospectively enrolled. EEG recordings were scored in a standardized manner and categorized. EEG category 1 consisted of continuous and reactive tracings. EEG category 2 consisted of continuous but unreactive tracings. EEG category 3 included those with any degree of discontinuity, burst suppression, or lack of cerebral activity. The primary outcome was unfavorable short-term outcome defined as Pediatric Cerebral Performance Category score of 4-6 (severe disability, vegetative, death) at hospital discharge. Univariate analyses of the association between EEG category and outcome was performed using logistic regression.

RESULTS

For tracings obtained during hypothermia, patients with EEGs in categories 2 or 3 were far more likely to have poor outcome than those in category 1 (OR 10.7, P = 0.023 and OR 35, P = 0.004, respectively). Similarly, for tracings obtained during normothermia, patients with EEGs in categories 2 or 3 were far more likely to have poor outcomes than those in category 1 (OR 27, P = 0.006 and OR 18, P = 0.02, respectively).

CONCLUSIONS

A simple EEG classification scheme has predictive value for short-term outcome in children undergoing TH after CA.

Prognosis after cardiac arrest and hypothermia: a new paradigm

Before the use of hypothermia as a treatment for comatose post-cardiac arrest patients, several prognostic variables were widely accepted as reliable and valid for the prediction of poor outcome. Recent studies using hypothermia have reported on patients with recovery of consciousness in spite of absent or extensor motor responses after 3 days, absent bilateral cortical N20 responses after 24 h, serum neuron-specific enolase levels greater than 33 μg/L, and early myoclonus status epilepticus. Hypothermia and its associated use of sedative and paralytic agents may delay neurologic recovery and affect the optimal timing of prognostic variables. Recent developments in brain imaging may provide additional objective prognostic information and deserve further study. Pending the results of future validation studies in patients treated with hypothermia, we recommend that irreversible management decisions not be made based on a single prognostic parameter, and, if there is uncertainty, these decisions be delayed for several days to allow for repeated testing.

Prognostic value of continuous EEG monitoring during therapeutic hypothermia after cardiac arrest

Introduction

Continuous EEG (cEEG) is increasingly used to monitor brain function in neuro-ICU patients. However, its value in patients with coma after cardiac arrest (CA), particularly in the setting of therapeutic hypothermia (TH), is only beginning to be elucidated. The aim of this study was to examine whether cEEG performed during TH may predict outcome.

Methods

From April 2009 to April 2010, we prospectively studied 34 consecutive comatose patients treated with TH after CA who were monitored with cEEG, initiated during hypothermia and maintained after rewarming. EEG background reactivity to painful stimulation was tested. We analyzed the association between cEEG findings and neurologic outcome, assessed at 2 months with the Glasgow-Pittsburgh Cerebral Performance Categories (CPC).

Results

Continuous EEG recording was started 12 ± 6 hours after CA and lasted 30 ± 11 hours. Nonreactive cEEG background (12 of 15 (75%) among nonsurvivors versus none of 19 (0) survivors; P < 0.001) and prolonged discontinuous "burst-suppression" activity (11 of 15 (73%) versus none of 19; P < 0.001) were significantly associated with mortality. EEG seizures with absent background reactivity also differed significantly (seven of 15 (47%) versus none of 12 (0); P = 0.001). In patients with nonreactive background or seizures/epileptiform discharges on cEEG, no improvement was seen after TH. Nonreactive cEEG background during TH had a positive predictive value of 100% (95% confidence interval (CI), 74 to 100%) and a false-positive rate of 0 (95% CI, 0 to 18%) for mortality. All survivors had cEEG background reactivity, and the majority of them (14 (74%) of 19) had a favorable outcome (CPC 1 or 2).

Conclusions

Continuous EEG monitoring showing a nonreactive or discontinuous background during TH is strongly associated with unfavorable outcome in patients with coma after CA. These data warrant larger studies to confirm the value of continuous EEG monitoring in predicting prognosis after CA and TH.

Continuous amplitude-integrated electroencephalogram predicts outcome in hypothermia-treated cardiac arrest patients

OBJECTIVE

To assess the prognostic value of continuous amplitude-integrated electroencephalogram in comatose survivors after cardiac arrest and treated with hypothermia.

DESIGN

Prospective observational study.

SETTING

General intensive care unit at a university hospital.

PATIENTS

Comatose patients after cardiac arrest and treated with hypothermia.

INTERVENTIONS

Patients were sedated and continuously monitored using an amplitude-integrated electroencephalogram. Monitoring was commenced on arrival in the intensive care unit and continued until recovery of consciousness, death, or 120 hrs after cardiac arrest. The amplitude-integrated electroencephalogram was interpreted together with the original electroencephalogram and analyzed without knowledge of the patient's clinical status. The amplitude-integrated electroencephalogram patterns at start of registration and at normothermia and the transitions of the amplitude-integrated electroencephalogram patterns over time were correlated to outcome.

MEASUREMENTS AND MAIN RESULTS

A total of 111 consecutive patients were assessed; 11 patients were not included because of technical reasons and five were excluded because of death before normothermia. Ninety-five patients remained; 57 (60%) eventually regained consciousness, of whom 49 (52%) lived an independent life at 6 months. Thirty-one patients (33%) at start of registration and 62 patients (65%) at normothermia had a continuous electroencephalogram pattern, and this was strongly associated with recovery of consciousness (29/31 [90%] and 54/62 [87%]). A suppression-burst pattern was always transient and patients with suppression-burst at any time remained in coma until death. An initial flat pattern was registered in 47 patients, but this had no prognostic value. Electrographic status epilepticus was a common finding (26/95 patients [27%]) and two types of electrographic status epilepticus were identified: one developed from suppression-burst and one developed from a continuous background. Two patients from the latter group regained consciousness.

CONCLUSIONS

Continuous amplitude-integrated electroencephalogram adds valuable early positive and negative prognostic information in comatose survivors after cardiac arrest. We identified two types of postanoxic electrographic status epilepticus, which is a novel finding with possible therapeutic implications.

Postresuscitation care: entering a new era

PURPOSE OF REVIEW

The purpose of this study is to discuss recent data relating to the treatment of cardiac arrest survivors. This is a rapidly evolving component of resuscitation medicine that impacts significantly on the quality of survival after cardiac arrest.

RECENT FINDINGS

The postcardiac arrest syndrome comprises postcardiac arrest brain injury, postcardiac arrest myocardial dysfunction, the systemic ischaemia/reperfusion response, and the persistent precipitating disease. Primary percutaneous coronary intervention is the preferred method for restoring coronary perfusion when cardiac arrest has been caused by an ST-elevation myocardial infarction. Many cardiac arrest survivors with non-ST-elevation myocardial infarction may also benefit from urgent percutaneous coronary intervention. Comatose cardiac arrest survivors should be managed with a moderate blood glucose target range of below 10 mmol/l (180 mg/dl). Therapeutic hypothermia is now generally accepted as part of a treatment strategy for comatose survivors of cardiac arrest, but its use may render conventional methods of prognostication unreliable.

SUMMARY

Survivors from cardiac arrest develop a postcardiac arrest syndrome. Postresuscitation care, including primary percutaneous coronary intervention, therapeutic hypothermia, and control of blood sugar, improves survival and neurological outcome in cardiac arrest survivors. Completely reliable prognostication in comatose survivors of cardiac arrest is difficult to achieve.

CT and MR in non-neonatal hypoxic-ischemic encephalopathy: radiological findings with pathophysiological correlations

Non-neonatal hypoxic-ischemic encephalopathy is a clinical condition often related to cardiopulmonary arrest that demands critical management and treatment decisions. Management depends mainly on the degree of neurological impairment and prognostic considerations. Computed tomography (CT) is often used to exclude associated or mimicking pathology. If any, only nonspecific signs such as cerebral edema, sulci effacement, and decreased gray matter (GM)/white matter (WM) differentiation are evident. Pseudosubarachnoid hemorrhage, a GM/WM attenuation ratio <1.18, and inverted GM attenuation are associated with a poor prognosis. Magnetic resonance (MR) imaging is more sensitive than CT in assessing brain damage in hypoxic-ischemic encephalopathy. Some MR findings have similarities to those seen pathologically, based on spatial distribution and time scale, such as lesions distributed in watershed regions and selective injury to GM structures. In the acute phase, lesions are better depicted using diffusion-weighted imaging (DWI) because of the presence of cytotoxic edema, which, on T2-weighted images, only become apparent later in the early subacute phase. In the late subacute phase, postanoxic leukoencephalopathy and contrast enhancement could be observed. In the chronic phase, atrophic changes predominate over tissue signal changes. MR can be useful for estimating prognosis when other tests are inconclusive. Some findings, such as the extent of lesions on DWI and presence of a lactate peak and depleted N-acetyl aspartate peak on MR spectroscopy, seem to have prognostic value.

Association between clinical examination and outcome after cardiac arrest

BACKGROUND

Neurologic prognostication after cardiac arrest relies on clinical examination findings derived before the advent of therapeutic hypothermia (TH). We measured the association between clinical examination findings at hospital arrival, 24, and 72 h after cardiac arrest in a modern intensive care unit setting.

METHODS

Between 1/1/2005 and 3/31/2009, hospital charts were reviewed in 272 subjects for neurologic examination findings (Glasgow Coma Score--motor examination, pupil response, corneal response) at hospital arrival, 24, and 72 h following cardiac arrest. Primary outcome was survival to hospital discharge. Secondary outcome was "good outcome," defined as discharge to home or acute rehabilitation facility.

RESULTS

Mean age was 61 years; 155 (57%) were male. Most were treated with TH (N=161; 59%) and 100 subjects (37%) were in ventricular fibrillation/ventricular tachycardia. Out-of-hospital cardiac arrest was common (N=169; 62%). Ninety-one (33%) survived, with 54 (20%) experiencing a good outcome. In subjects with a GCS Motor score < or = 3 at 24 and 72 h survival was 17% (13/76; 95% CI 7.9-26.2%) and 20% (6/27; 95% CI 6.3-33.6%), respectively. Subjects with a GCS Motor score < or = 2 at 24 and 72 h survived in 14% (9/66; 95% CI 4.6-22.6%) and 18% (6/33; 95% CI 3.5-32.8%), respectively. Absent pupil reactivity on arrival did not exclude survival (7/65; 11%; 95% CI 2.4-19%). A lack of pupil reactivity or corneal response at 72 h was associated with death (pupil: 0/17; 95% CI 0, 2.9%; corneal: 0/21; 95% CI 0, 2.4%).

CONCLUSIONS

GCS Motor score < or = 3 or < or = 2 at 24 or 72 h following cardiac arrest does not exclude survival or good outcome. However, absent pupil or corneal response at 72 h appears to exclude survival and good outcome.

Anesthesia and analgesia protocol during therapeutic hypothermia after cardiac arrest: a systematic review

BACKGROUND

Present practice guidelines recommend sedative-analgesic and neuromuscular blocking administration during therapeutic hypothermia in comatose patients after cardiac arrest. However, none suggests the best administration protocol. In this study, we evaluated intensivists' preferences regarding administration.

METHODS

A systematic literature review was conducted to identify clinical studies published between 1997 and July 2009. Selected articles had to meet the following criteria: use of hypothermia to improve neurologic outcome after cardiac arrest, and specific mention of the sedative protocol used. We checked drugs and dose used, the reason for their administration, and the specific type of neurologic and neuromuscular monitoring used.

RESULTS

We identified 44 studies reporting protocols used in 68 intensive care units (ICUs) from various countries. Midazolam, the sedative used most often, was used in 39 ICUs at doses between 5 mg/h and 0.3 mg/kg/h. Propofol was used in 13 ICUs at doses up to 6 mg/kg/h. Eighteen ICUs (26%) did not report using any analgesic. Fentanyl was the analgesic used the most, in 33 ICUs, at doses between 0.5 and 10 microg/kg/h, followed by morphine in 4 ICUs. Neuromuscular blocking drugs were routinely used to prevent shivering in 54 ICUs and to treat shivering in 8; in 1 ICU, their use was discouraged. Pancuronium was used the most, in 24 ICUs, followed by cisatracurium in 14. Four ICUs used neuromuscular blocking drug administration guided by train-of-four monitoring and 3 ICUs used continuous monitoring of cerebral activity.

CONCLUSIONS

There is great variability in the protocols used for anesthesia and analgesia during therapeutic hypothermia. Very often, the drug and the dose used do not seem the most appropriate. Only 3 ICUs routinely used electroencephalographic monitoring during paralysis. It is necessary to reach a consensus on how to treat this critical care population.

Status epilepticus

Status epilepticus (SE) still results in significant mortality and morbidity. Whereas mortality depends mainly on the age of the patient as well as etiology, morbidity often results from a myriad of complications that occur during prolonged admission to an intensive care environment. Although SE is a clinical diagnosis in most cases (convulsant), its treatment requires support by continuous electroencephalographic recording to ensure cessation of potential nonconvulsive elements of SE. Treatment must be initiated as early as possible and consists of benzodiazepine administration and supportive measures for the airway and circulation. These initial interventions are followed by effective intravenous antiepileptic drugs. If the SE becomes refractory, more complex intensive care interventions, such as induction of barbiturate coma, need to be pursued. Data regarding the role of more recently available antiepileptic drugs in treating SE also are discussed in this review.

Nonconvulsive status epilepticus and coma

Nonconvulsive status epilepticus (NCSE) in a comatose patient cannot be diagnosed without electroencephalography (EEG). In many advanced coma stages, the EEG exhibits continuous or periodic EEG abnormalities, but their causal role in coma remains unclear in many cases. To date there is no consensus on whether to treat NCSE in a comatose patient in order to improve the outcome or to retract from treatment, as these EEG patterns might reflect the end stages of a dying brain. On the basis of EEG, NCSE in comatose patients may be classified as generalized or lateralized. This review aims to summarize the ongoing debate of NCSE and coma and to critically reassess the available literature on coma with epileptiform EEG pattern and its prognostic and therapeutic implications. The authors suggest distinguishing NCSE proper and comatose NCSE, which includes coma with continuous lateralized discharges or generalized epileptiform discharges (coma-LED, coma-GED). Although NCSE proper is accompanied by clinical symptoms suggestive of status epilepticus and mild impairment of consciousness, such as in absence status or complex focal status epilepticus, coma-LED and coma-GED represent deep coma of various etiology without any clinical motor signs of status epilepticus but with characteristic epileptiform EEG pattern. Hence coma-LED and coma-GED can be diagnosed with EEG only. Subtle or stuporous status epilepticus and epilepsia partialis continua-like symptoms in severe acute central nervous system (CNS) disorders represent the borderland in this biologic continuum between NCSE proper and comatose NCSE (coma-LED/GED). This pragmatic differentiation could act as a starting point to solve terminologic and factual confusion.