Cardiac arrest and therapeutic hypothermia: Prognosis and outcome

Abstract Therapeutic hypothermia (TH) is the only treatment available to reduce neurological sequels for unconscious patients following cardiac arrest (CA). TH requires sedation and muscular relaxation, obscuring the clinical neurological examination for estimation of prognosis, and clinical decision making. Continuous amplitude-integrated EEG (aEEG) has been used to predict outcome in neonates suffering from asphyxia. In adults following CA and TH, the novel observation was made that a continuous aEEG-pattern prior to or at normothermia strongly correlated to return of consciousness, while other patterns strongly correlated to continued coma. A status epilepticus aEEG-pattern carried a poor, but not desolate prognosis. Biochemical neuronal-markers (neuron-specific enolase (NSE) and S-100B) have previously been assessed in non-TH CA patients. In TH, an NSE level of 28 μg/l 48h after CA, or an increase of more than 2 μg/l between 24 and 48h were strongly associated to a poor outcome. Five days after the CA, one third of the patients remained in coma. They either had multimodal signs of extensive brain damage (high NSE levels, ischemic changes on MRI or neurophysiological evidence of advanced brain damage (bilateral lack of SSEP)), or showed sustained unconsciousness and a status epilepticus aEEG-pattern. Unconscious patients without these signs of brain injury eventually regained consciousness. Approximately 50% of hypothermia treated patients regained consciousness. Ninety-eight percent of surviving patients had an independent lifestyle six months after the CA. The dominant cognitive problem was a disturbed memory function. Taken together, aEEG appears superior in early neurological prognostication in these patients

Study, definition and analysis of pilot/system performance measurements for planetary entry experiments

Definition analysis for experimental prediction of pilot performance during planetary entr

An in-depth characterisation of neonatal seizures by early continuous video-EEG analysis

Introduction Seizures are harmful to the neonatal brain; this compels many clinicians and researchers to persevere further in optimizing every aspects of managing neonatal seizures. Aims To delineate the seizure profile between non-cooled versus cooled neonates with hypoxic-ischaemic encephalopathy (HIE), in neonates with stroke, the response of seizure burden to phenobarbitone and to quantify the degree of electroclinical dissociation (ECD) of seizures. Methods The multichannel video-EEG was used in this research study as the gold standard to detect seizures, allowing accurate quantification of seizure burden to be ascertained in term neonates. The entire EEG recording for each neonate was independently reviewed by at least 1 experienced neurophysiologist. Data were expressed in medians and interquartile ranges. Linear mixed models results were presented as mean (95% confidence interval); p values <0.05 were deemed as significant. Results Seizure burden in cooled neonates was lower than in non-cooled neonates [60(39-224) vs 203(141-406) minutes; p=0.027]. Seizure burden was reduced in cooled neonates with moderate HIE [49(26-89) vs 162(97-262) minutes; p=0.020] when compared with severe HIE. In neonates with stroke, the background pattern showed suppression over the infarcted side and seizures demonstrated a characteristic pattern. Compared with 10 mg/kg, phenobarbitone doses at 20 mg/kg reduced seizure burden (p=0.004). Seizure burden was reduced within 1 hour of phenobarbitone administration [mean (95% confidence interval): -14(-20 to -8) minutes/hour; p<0.001], but seizures returned to pre-treatment levels within 4 hours (p=0.064). The ECD index in cooled, non-cooled neonates with HIE, stroke and in neonates with other diagnoses were 88%, 94%, 64% and 75% respectively. Conclusions Further research exploring the treatment effects on seizure burden in the neonatal brain is required. A change to our current treatment strategy is warranted as we continue to strive for more effective seizure control, anchored with use of the multichannel EEG as the surveillance tool

Therapeutic Hypothermia in Brain Injury

This book describes the evidence behind the application of Therapeutic Hypothermia on patients with injury to the brain and spinal cord, that includes ischemia reperfusion after cardiac arrest or asphyxiation, traumatic brain injury, acute ischemic stroke, hemorrhagic stroke, refractory intracranial hypertension, cerebral edema in acute liver failure, subarachnoid hemorrhage, as well as spinal cord injury. This book discusses the mechanisms by which therapeutic hypothermia can mitigate the pathophysiologies responsible for secondary brain injury, and provides information to help guide this treatment with regard to timing, depth, duration, and management of side-effects. The book also discusses the methods and technologies used to induce and maintain therapeutic hypothermia. It also describes how hypothermia can influence the ability to prognosticate these injured patients and provides grounds for future directions in the application of and research with therapeutic hypothermia

Cardiac arrest – prognostic biomarkers and aspects of shock

Background: Some improvement has been seen in survival after cardiac arrest but the outcome is still poor and 50-70% of patients do not survive despite successful return of spontaneous circulation (ROSC). The cause of death is multifactorial. The majority of patients die from brain injury, but up to 35% die as a result of circulatory failure. Purpose: First, to investigate the release profiles of an array of biomarkers in patients treated with mild induced hypothermia after cardiac arrest and study their correlation to the post-cardiac arrest syndrome (PCAS) and long-term outcome; Second, to investigate the effect of two different target temperatures (33°C and 36°C) on hemodynamics and vasopressor requirement in cardiac arrest patients and; Third, to investigate the association of target temperature with outcome in patients with shock in admission. Methods: The biomarkers were collected serially at 8 time points during the first 72 hours following cardiac arrest in 84 still comatose post-resuscitation cardiac arrest patients treated with mild induced hypothermia. We analysed markers of inflammation; procalcitonin (PCT) and c-reactive protein (CRP), oxidation; peroxiredoxin 4 (prx4), cardiac stress; MR-proANP, cardiac injury; Troponin T (TnT), brain injury; Neuron specific enlolase (NSE), and the stress hormone; CT-proAVP (copeptin). Outcome was assessed at 6 months with the cerebral performance category scale (CPC) where CPC 1-2 was considered a good outcome. The cardiovascular sequential organ failure assessment score (SOFA-score) and the time to ROSC were used as surrogate markers for the PCAS. Three different definitions of infection were used to assess occurrence of infection. The effect of a target temperature of 33°C or 36°C on hemodynamics was investigated in all patients with available vasopressor data (n=920) in the ‘Targeted temperature management at 33°C versus 36°C after cardiac arrest’ trial and in patients with shock on admission (n=139). Primary outcome was mortality. Secondary outcomes were vasopressor requirements as assessed by the cardiovascular SOFA-score, serum lactate concentrations, mean arterial pressure, and heart rate. Results: PCT, CT-proAVP and MR-proANP were all significantly higher in patients with poor outcome and correlated to surrogate markers of the PCAS. No specific cut-off levels were identified. PCT release was not associated to infection. Combinations of biomarkers may be a promising concept to improve prognostication. A targeted temperature of 33°C was associated with increased vasopressor requirements and increased lactate levels in both our investigated cohorts. A low MAP during the intervention (0-36 hours) was associated with poor outcome after adjustment for baseline characteristics. Conclusion: Biomarkers from other sources than the brain are associated to the PCAS and may be promising biomarkers to prognosticate outcome, alone or in combination. Targeted temperature management at 33°C is associated with increased vasopressor requirements and severity of shock and does not improve outcome as compared to 36°C

Aerospace Medicine and biology: A continuing bibliography with indexes, supplement 123, January 1974

This special bibliography lists 226 reports, articles, and other documents introduced into the NASA scientific and technical information system in Dec. 1973

Soviet space biology and medicine

Review of Soviet space biology and medicin

The influence of criterion shifts on electrophysiological correlates of recognition memory

The claim that event-related potentials (ERPs) index familiarity was assessed by acquiring ERPs during a recognition memory task in which participants were instructed to adopt different decision criteria in separate retrieval phases. In one, the instructions were to respond 1Cold 1D only when confident that this was the correct response, and to respond 1Cnew 1D otherwise (the conservative condition). In the other, the instructions were to respond new only when confident that this was the correct response (the liberal condition). The rationale for this approach was that the level of familiarity licensing an old response would be higher in the conservative than in the liberal condition, and if ERPs index familiarity, this would be reflected in changes to the putative ERP index. This index comprises relatively more positive-going neural activity for correct judgments to old than to new items, which is evident from 300 to 500 msec poststimulus at mid-frontal scalp locations. In keeping with task instructions, participants made more old responses in the liberal than in the conservative condition. There were reliable mid-frontal ERP old/new effects in both conditions, and the ERPs evoked by correct judgments to words in the conservative condition were relatively more positive-going than those in the liberal condition. This finding is consistent with the view that the mid-frontal ERP old/new effect indexes familiarity, and in combination with other ERP findings, provides strong support for dual-process accounts of recognition memory