Postanoxic Patients Research Articles

Serum procalcitonin as a marker of post-cardiac arrest syndrome and long-term neurological recovery, but not of early-onset infections, in comatose post-anoxic patients treated with therapeutic hypothermia

ObjectiveTo examine the relationship of early serum procalcitonin (PCT) levels with the severity of post-cardiac arrest syndrome (PCAS), long-term neurological recovery and the risk of early-onset infections in patients with coma after cardiac arrest (CA) treated with therapeutic hypothermia (TH). MethodsA prospective cohort of adult comatose CA patients treated with TH (33°C, for 24h) admitted to the medical/surgical intensive care unit, Lausanne University Hospital, was studied. Serum PCT was measured early after CA, at two time-points (days 1 and 2). The SOFA score was used to quantify the severity of PCAS. Diagnosis of early-onset infections (within the first 7 days of ICU stay) was made after review of clinical, radiological and microbiological data. Neurological recovery at 3 months was assessed with Cerebral Performance Categories (CPC), and was dichotomized as favorable (CPC 1–2) vs. unfavorable (CPC 3–5). ResultsFrom December 2009 to April 2012, 100 patients (median age 64 [interquartile range 55–73] years, median time from collapse to ROSC 20 [11–30]min) were studied. Peak PCT correlated with SOFA score at day 1 (Spearman's R=0.44, p<0.0001) and was associated with neurological recovery at 3 months (peak PCT 1.08 [0.35–4.45]ng/ml in patients with CPC 1–2 vs. 3.07 [0.89–9.99] ng/ml in those with CPC 3–5, p=0.01). Peak PCT did not differ significantly between patients with early-onset vs. no infections (2.14 [0.49–6.74] vs. 1.53 [0.46–5.38]ng/ml, p=0.49). ConclusionsEarly elevations of serum PCT levels correlate with the severity of PCAS and are associated with worse neurological recovery after CA and TH. In contrast, elevated serum PCT did not correlate with early-onset infections in this setting.

A Cerebral Recovery Index (CRI) for early prognosis in patients after cardiac arrest

IntroductionElectroencephalogram (EEG) monitoring in patients treated with therapeutic hypothermia after cardiac arrest may assist in early outcome prediction. Quantitative EEG (qEEG) analysis can reduce the time needed to review long-term EEG and makes the analysis more objective. In this study, we evaluated the predictive value of qEEG analysis for neurologic outcome in postanoxic patients.MethodsIn total, 109 patients admitted to the ICU for therapeutic hypothermia after cardiac arrest were included, divided over a training and a test set. Continuous EEG was recorded during the first 5 days or until ICU discharge. Neurologic outcomes were based on the best achieved Cerebral Performance Category (CPC) score within 6 months. Of the training set, 27 of 56 patients (48%) and 26 of 53 patients (49%) of the test set achieved good outcome (CPC 1 to 2). In all patients, a 5 minute epoch was selected each hour, and five qEEG features were extracted. We introduced the Cerebral Recovery Index (CRI), which combines these features into a single number.ResultsAt 24 hours after cardiac arrest, a CRI <0.29 was always associated with poor neurologic outcome, with a sensitivity of 0.55 (95% confidence interval (CI): 0.32 to 0.76) at a specificity of 1.00 (CI, 0.86 to 1.00) in the test set. This results in a positive predictive value (PPV) of 1.00 (CI, 0.73 to 1.00) and a negative predictive value (NPV) of 0.71 (CI, 0.53 to 0.85). At the same time, a CRI >0.69 predicted good outcome, with a sensitivity of 0.25 (CI, 0.10 to 0.14) at a specificity of 1.00 (CI, 0.85 to 1.00) in the test set, and a corresponding NPV of 1.00 (CI, 0.54 to 1.00) and a PPV of 0.55 (CI, 0.38 to 0.70).ConclusionsWe introduced a combination of qEEG measures expressed in a single number, the CRI, which can assist in prediction of both poor and good outcomes in postanoxic patients, within 24 hours after cardiac arrest.

Continuous electroencephalography monitoring for early prediction of neurological outcome in postanoxic patients after cardiac arrest

To evaluate the value of continuous electroencephalography in early prognostication in patients treated with hypothermia after cardiac arrest. Prospective cohort study. Medical intensive care unit. Sixty patients admitted to the intensive care unit for therapeutic hypothermia after cardiac arrest. None. In all patients, continuous electroencephalogram and daily somatosensory evoked potentials were recorded during the first 5 days of admission or until intensive care unit discharge. Neurological outcomes were based on each patient's best achieved Cerebral Performance Category score within 6 months. Twenty-seven of 56 patients (48%) achieved good neurological outcome (Cerebral Performance Category score 1-2).At 12 hrs after resuscitation, 43% of the patients with good neurological outcome showed continuous, diffuse slow electroencephalogram rhythms, whereas this was never observed in patients with poor outcome.The sensitivity for predicting poor neurological outcome of low-voltage and isoelectric electroencephalogram patterns 24 hrs after resuscitation was 40% (95% confidence interval 19%-64%) with a 100% specificity (confidence interval 86%-100%), whereas the sensitivity and specificity of absent somatosensory evoked potential responses during the first 24 hrs were 24% (confidence interval 10%-44%) and 100% (confidence interval: 87%-100%), respectively. The negative predictive value for poor outcome of low-voltage and isoelectric electroencephalogram patterns was 68% (confidence interval 50%-81%) compared to 55% (confidence interval 40%-60%) for bilateral somatosensory evoked potential absence, both with a positive predictive value of 100% (confidence interval 63%-100% and 59%-100% respectively). Burst-suppression patterns after 24 hrs were also associated with poor neurological outcome, but not inevitably so. In patients treated with hypothermia, electroencephalogram monitoring during the first 24 hrs after resuscitation can contribute to the prediction of both good and poor neurological outcome. Continuous patterns within 12 hrs predicted good outcome. Isoelectric or low-voltage electroencephalograms after 24 hrs predicted poor outcome with a sensitivity almost two times larger than bilateral absent somatosensory evoked potential responses.

The N20 in post-anoxic coma: Are you listening?

ObjectivePersistent absence of the median nerve N20 response in patients suffering from postanoxic coma after a cardiac arrest is invariably associated with a poor outcome. Preservation of the N20 response, however, does not indicate a good recovery. We wish to improve our understanding on this issue. MethodsWe discuss the limited specificity of the presence of the N20 response regarding a favourable outcome and the selective neuronal damage that may be responsible for this clinical scenario. We also present EEG and SSEP data from post-anoxic patients. ResultsWe show data from a patient suffering from a severe post-anoxic encephalopathy, with a nearly flat EEG recording, but preserved N20 responses obtained after median nerve stimulation and propose a simple model for these observations. ConclusionsSomatosensory neurons have both “receiving” and “sending” properties, where the latter mainly reflects cortical synaptic function. After hypoxic insults, these two modes may be selectively damaged. Preservation of the N20 reflects an intact “receiving mode”, while the EEG mainly reflects the “sending mode”. SignificanceInsight into the physiological processes underlying the generation of the SSEP and the EEG is relevant in clinical decision making and may guide novel monitoring strategies.

Uncommon EEG burst-suppression in severe postanoxic encephalopathy

In patients suffering from severe hypoxia, the EEG may show a burst-suppression pattern, characterized by low-voltage activity and the occurrence of high amplitude burst-like events. We describe the two-timescale burst phenomenology of this postanoxic condition. We present EEG recordings showing remarkable burst phenomenology in two postanoxic patients and consider potential mechanisms responsible for the generation of the burst-suppression patterns. We quantify the postanoxic condition in terms of the dimension (number of degrees of freedom) of its dynamics by comparing our data with a system of three ordinary differential equations with two timescales subject to varying degrees of noise. EEGs displayed extreme similarity of the bursts, separated by interburst intervals up to more than 300s. This pattern reflects a significant reduction in the number of functional brain states. This post-anoxic condition is found to have dimension 3, consisting of fast dynamics responsible for the bifurcation to bursting behavior, and a long time-scale responsible for burst termination and the interburst intervals. Low-dimensional postanoxic brain states, as manifested by burst-similarity, appears to indicate an irreversible loss of brain function and consciousness. Evidence of brain functionality in a persistent low dimensional state due to severe hypoxia is indicative of permanent loss of consciousness with essentially no chance for recovery. Quantitative evidence for such degenerate states is important for clinical decision making.

Novel anesthetics and other treatment strategies for refractory status epilepticus

Novel anesthetics and other treatment strategies for refractory status epilepticus

Status epilepticus

Prognosis of status epilepticus (SE) depends on its cause, but there is uncertainty as to whether SE represents an independent outcome predictor for a given etiology. Cerebral anoxia is a relatively homogenous severe encephalopathy. Postanoxic SE is associated to a nearly 100% mortality in this setting; however, it is still unclear whether this is a severity marker of the underlying encephalopathy, or an independent factor influencing outcome. The goal of this study was to assess if postanoxic SE is independently associated with mortality after cerebral anoxia. This was a retrospective observation of consecutive comatose survivors of cardiac arrest, including subjects treated with hypothermia. On the subgroup with EEG recordings in the first hospitalization days, univariate and multivariate analyses were applied to potential determinants of in-hospital mortality, and included the following variables: age, gender, type and length of cardiac arrest, occurrence of circulatory shock, presence of therapeutic hypothermia, and electrographic SE. Out of 166 postanoxic patients, 107 (64%) had an EEG (median latency from admission, 2 days); in this group, therapeutic hypothermia was administered in 59%. Death occurred in 71 (67%) patients. Postanoxic SE was associated with mortality regardless of type of acute cardiac rhythm and administration of hypothermic treatment. In this hospital-based cohort, postanoxic status epilepticus (SE) seems to be independently related to death in cardiac arrest survivors, suggesting that SE might determine a bad prognosis for a given etiology. Confirmation of these results in a prospective assessment is needed.

Effect of deep brain stimulation of GPI on neuronal activity of the thalamic nucleus ventralis oralis in a dystonic patient

Objective. – To record the possible effect of acute deep brain stimulation (DBS) of the globus pallidus internus (GPI) on the neuronal activity of the ventralis oralis anterior (VOA) nucleus of the thalamus. Methods. – Under general propofol anaesthesia, extracelullar single unit recordings were performed in VOA of a post-anoxic dystonic patient previously implanted with GPI located electrodes for chronic DBS. Results. – Neurons recorded in the VOA could be classified in two cell subpopulations: a high firing rate (16.5 Hz) and low burst index (BI; 15.6) type and a low firing rate (5.5 Hz) and high BI (35.6) type. GPI electrical stimulation reduced the frequency and increased the BI of the high firing rate cells while leaving the other cell type unchanged. Conclusion. – These results demonstrate that pallidal DBS is able to inhibit a subpopulation of motor thalamic cells and question the pathophysiological model of dystonia based on a low firing rate of GPI cells.

Incidence and short-term prognosis of status epilepticus in adults in Bologna, Italy.

To determine the incidence and the 30-day case fatality of status epilepticus (SE) in the adult resident population of the city of Bologna, Italy. Over a 1-year period (March 1, 1999 to February 29, 2000), all patients older than 20 years with SE were included. The case-finding method was based on (a) a prospective surveillance of all public general hospitals in the city by neurologic units, and (b) a review of all discharge codes concerning epilepsy. The crude and standardized annual incidence rate of SE was 13.1 per 100,000 [95% confidence interval (CI), 9.5-17.5] and 10.7 (95% CI, 7.5-13.8). It was higher in the elderly (older than 60 years) than in young adults (26.2 vs. 5.2) and in women than in men (14.9 vs. 11.0). Acute symptomatic SE accounted for 48%, and a cerebrovascular pathology was the most frequently associated etiologic condition (41%). A history of seizures was reported in 39% of patients. The 30-day case fatality was 39% (33% excluding postanoxic patients). This study reports the first data on the epidemiology of SE in Italy. The incidence rate found in the population of Bologna is in the same range as that of the other European countries. The 30-day case fatality is higher than all the other population studies (both European and American), despite the broadly similar clinical features of patients. Indirect evidence suggests that some inaccurate patient management could have negatively influenced the outcome of SE.

Transient Eye Opening With EEG Suppression-Burst Pattern in Postanoxic Encephalopathy-Reply

In Reply. —We wish to thank Mori et al for their observations and comments concerning the association of transient eye opening with EEG suppression-burst pattern in severe anoxic encephalopathy. There are ten cases of this phenomenon with which we are personally familiar—all with rapidly fatal outcomes. The presence of a survivor with this phenomenon is most interesting, especially in view of the EEG transition to another pattern of poor prognosis, ie, a generalized periodic pattern reminiscent of Creutzfeldt-Jakob disease (although this pattern is often associated with myoclonus in the postanoxic patient). The prognosis in these patients is most likely related to the severity of the anoxia, and the suppression-burst pattern is merely a reflection of this severe metabolic insult. Prior1predicted approximately a 92% mortality with the suppression-burst pattern after cardiopulmonary arrest. Other authors, including Kuroiwa et al,2also suggest a very high mortality (approaching 96%) in patients with suppression-burst