Brain monitoring after cardiac arrest

Purpose of reviewTo describe the available neuromonitoring tools in patients who are comatose after resuscitation from cardiac arrest because of hypoxic-ischemic brain injury (HIBI).Recent findingsElectroencephalogram (EEG) is useful for detecting seizures and guiding antiepileptic treatment. Moreover, specific EEG patterns accurately identify patients with irreversible HIBI. Cerebral blood flow (CBF) decreases in HIBI, and a greater decrease with no CBF recovery indicates poor outcome. The CBF autoregulation curve is narrowed and right-shifted in some HIBI patients, most of whom have poor outcome. Parameters derived from near-infrared spectroscopy (NIRS), intracranial pressure (ICP) and transcranial Doppler (TCD), together with brain tissue oxygenation, are under investigation as tools to optimize CBF in patients with HIBI and altered autoregulation. Blood levels of brain biomarkers and their trend over time are used to assess the severity of HIBI in both the research and clinical setting, and to predict the outcome of postcardiac arrest coma. Neuron-specific enolase (NSE) is recommended as a prognostic tool for HIBI in the current postresuscitation guidelines, but other potentially more accurate biomarkers, such as neurofilament light chain (NfL) are under investigation.Neuromonitoring provides essential information to detect complications, individualize treatment and predict prognosis in patients with HIBI.Peer reviewe

Targeted temperature management and cardiac arrest after the TTM-2 study

Non peer reviewe

Effect of intra-arrest trans-nasal evaporative cooling in out-of-hospital cardiac arrest: a pooled individual participant data analysis

Randomized trials have shown that trans-nasal evaporative cooling initiated during CPR (i.e. intra-arrest) effectively lower core body temperature in out-of-hospital cardiac arrest patients. However, these trials may have been underpowered to detect significant differences in neurologic outcome, especially in patients with initial shockable rhythm.Peer reviewe

Quality of targeted temperature management and outcome of out-of-hospital cardiac arrest patients : A post hoc analysis of the TTH48 study

Background: No data are available on the quality of targeted temperature management (TTM) provided to out-of-hospital cardiac arrest (OHCA) patients and its association with outcome. Methods: Post hoc analysis of the TTH48 study (NCT01689077), which compared the effects of prolonged TTM at 33 degrees C for 48 h to standard 24-h TTM on neurologic outcome. Admission temperature, speed of cooling, rewarming rates, precision (i.e. temperature variability), overcooling and overshooting as post-cooling fever (i.e. >38.0 degrees C) were collected. A specific score, ranging from 1 to 9, was computed to define the "quality of TTM". Results: On a total of 352 patients, most had a moderate quality of TTM (n = 217; 62% - score 4-6), while 80 (23%) patients had a low quality of TTM (score 1-3) and only 52 (16%) a high quality of TTM (score 7-9). The proportion of patients with unfavorable neurological outcome (UO; Cerebral Performance Category of 3-5 at 6 months) was similar between the different quality of TTM groups (p = 0.90). Although a shorter time from arrest to target temperature and a lower proportion of time outside the target ranges in the TTM 48-h than in the TTM 24-h group, quality of TTM was similar between groups. Also, the proportion of patients with UO was similar between the different quality of TTM groups when TTM 48-h and TTM 24-h were compared. Conclusions: In this study, high quality of TTM was provided to a small proportion of patients. However, quality of TTM was not associated with patients' outcome.Peer reviewe

Characteristics and outcomes of cancer patients in European ICUs

Increasing numbers of cancer patients are being admitted to the intensive care unit (ICU), either for cancer-related complications or treatment-associated side effects, yet there are relatively few data concerning the epidemiology and prognosis of cancer patients admitted to general ICUs. The aim of this study was to assess the characteristics of critically ill cancer patients, and to evaluate their prognosis.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Recommended β-lactam regimens are inadequate in septic patients treated with continuous renal replacement therapy

Introduction: Sepsis is responsible for important alterations in the pharmacokinetics of antibiotics. Continuous renal replacement therapy (CRRT), which is commonly used in septic patients, may further contribute to pharmacokinetic changes. Current recommendations for antibiotic doses during CRRT combine data obtained from heterogeneous patient populations in which different CRRT devices and techniques have been used. We studied whether these recommendations met optimal pharmacokinetic criteria for broad-spectrum antibiotic levels in septic shock patients undergoing CRRT.Methods: This open, prospective study enrolled consecutive patients treated with CRRT and receiving either meropenem (MEM), piperacillin-tazobactam (TZP), cefepime (FEP) or ceftazidime (CAZ). Serum concentrations of these antibiotics were determined by high-performance liquid chromatography from samples taken before (t = 0) and 1, 2, 5, and 6 or 12 hours (depending on the β-lactam regimen) after the administration of each antibiotic. Series of measurements were separated into those taken during the early phase ( 48 hours).Results: A total of 69 series of serum samples were obtained in 53 patients (MEM, n = 17; TZP, n = 16; FEP, n = 8; CAZ, n = 12). Serum concentrations remained above four times the minimal inhibitory concentration for Pseudomonas spp. for the recommended time in 81% of patients treated with MEM, in 71% with TZP, in 53% with CAZ and in 0% with FEP. Accumulation after 48 hours of treatment was significant only for MEM.Conclusions: In septic patients receiving CRRT, recommended doses of β-lactams for Pseudomonas aeruginosa are adequate for MEM but not for TZP, FEP and CAZ; for these latter drugs, higher doses and/or extended infusions should be used to optimise serum concentrations. © 2011 Seyler et al. licensee BioMed Central Ltd.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Optic nerve sheath diameter measured sonographically as non-invasive estimator of intracranial pressure: a systematic review and meta-analysis

Purpose: Although invasive intracranial devices (IIDs) are the gold standard for intracranial pressure (ICP) measurement, ultrasonography of the optic nerve sheath diameter (ONSD) has been suggested as a potential non-invasive ICP estimator. We performed a meta-analysis to evaluate the diagnostic accuracy of sonographic ONSD measurement for assessment of intracranial hypertension (IH) in adult patients. Methods: We searched on electronic databases (MEDLINE/PubMed\uae, Scopus\uae, Web of Science\uae, ScienceDirect\uae, Cochrane Library\uae) until 31 May 2018 for comparative studies that evaluated the efficacy of sonographic ONSD vs. ICP measurement with IID. Data were extracted independently by two authors. We used the QUADAS-2 tool for assessing the risk of bias (RB) of each study. A diagnostic meta-analysis following the bivariate approach and random-effects model was performed. Results: Seven prospective studies (320 patients) were evaluated for IH detection (assumed with ICP > 20 mmHg or > 25 cmH2O). The accuracy of included studies ranged from 0.811 (95% CI 0.678\u20120.847) to 0.954 (95% CI 0.853\u20120.983). Three studies were at high RB. No significant heterogeneity was found for the diagnostic odds ratio (DOR), positive likelihood ratio (PLR) and negative likelihood ratio (NLR), with I2< 50% for each parameter. The pooled DOR, PLR and NLR were 67.5 (95% CI 29\u2012135), 5.35 (95% CI 3.76\u20127.53) and 0.088 (95% CI 0.046\u20120.152), respectively. The area under the hierarchical summary receiver-operating characteristic curve (AUHSROC) was 0.938. In the subset of five studies (275 patients) with IH defined for ICP > 20 mmHg, the pooled DOR, PLR and NLR were 68.10 (95% CI 26.8\u2012144), 5.18 (95% CI 3.59\u20127.37) and 0.087 (95% CI 0.041\u20120.158), respectively, while the AUHSROC was 0.932. Conclusions: Although the wide 95% CI in our pooled DOR suggests caution, ultrasonographic ONSD may be a potentially useful approach for assessing IH when IIDs are not indicated or available (CRD42018089137, PROSPERO)

Optimizing sedation in patients with acute brain injury.

Daily interruption of sedative therapy and limitation of deep sedation have been shown in several randomized trials to reduce the duration of mechanical ventilation and hospital length of stay, and to improve the outcome of critically ill patients. However, patients with severe acute brain injury (ABI; including subjects with coma after traumatic brain injury, ischaemic/haemorrhagic stroke, cardiac arrest, status epilepticus) were excluded from these studies. Therefore, whether the new paradigm of minimal sedation can be translated to the neuro-ICU (NICU) is unclear. In patients with ABI, sedation has 'general' indications (control of anxiety, pain, discomfort, agitation, facilitation of mechanical ventilation) and 'neuro-specific' indications (reduction of cerebral metabolic demand, improved brain tolerance to ischaemia). Sedation also is an essential therapeutic component of intracranial pressure therapy, targeted temperature management and seizure control. Given the lack of large trials which have evaluated clinically relevant endpoints, sedative selection depends on the effect of each agent on cerebral and systemic haemodynamics. Titration and withdrawal of sedation in the NICU setting has to be balanced between the risk that interrupting sedation might exacerbate brain injury (e.g. intracranial pressure elevation) and the potential benefits of enhanced neurological function and reduced complications. In this review, we provide a concise summary of cerebral physiologic effects of sedatives and analgesics, the advantages/disadvantages of each agent, the comparative effects of standard sedatives (propofol and midazolam) and the emerging role of alternative drugs (ketamine). We suggest a pragmatic approach for the use of sedation-analgesia in the NICU, focusing on some practical aspects, including optimal titration and management of sedation withdrawal according to ABI severity

Cerebral microcirculation is impaired during sepsis: an experimental study

INTRODUCTION: Pathophysiology of brain dysfunction due to sepsis remains poorly understood. Cerebral microcirculatory alterations may play a role; however, experimental data are scarce. This study sought to investigate whether the cerebral microcirculation is altered in a clinically relevant animal model of septic shock. METHODS: Fifteen anesthetized, invasively monitored, and mechanically ventilated female sheep were allocated to a sham procedure (n = 5) or sepsis (n = 10), in which peritonitis was induced by intra-abdominal injection of autologous faeces. Animals were observed until spontaneous death or for a maximum of 20 hours. In addition to global hemodynamic assessment, the microcirculation of the cerebral cortex was evaluated using Sidestream Dark-Field (SDF) videomicroscopy at baseline, 6 hours, 12 hours and at shock onset. At least five images of 20 seconds each from separate areas were recorded at each time point and stored under a random number to be analyzed, using a semi-quantitative method, by an investigator blinded to time and condition. RESULTS: All septic animals developed a hyperdynamic state associated with organ dysfunction and, ultimately, septic shock. In the septic animals, there was a progressive decrease in cerebral total perfused vessel density (from 5.9 ± 0.9 at baseline to 4.8 ± 0.7 n/mm at shock onset, P = 0.009), functional capillary density (from 2.8 ± 0.4 to 2.1 ± 0.7 n/mm, P = 0.049), the proportion of small perfused vessels (from 95 ± 3 to 85 ± 8%, P = 0.02), and the total number of perfused capillaries (from 22.7 ± 2.7 to 17.5 ± 5.2 n/mm, P = 0.04). There were no significant changes in microcirculatory flow index over time. In sham animals, the cerebral microcirculation was unaltered during the study period. CONCLUSIONS: In this model of peritonitis, the cerebral microcirculation was impaired during sepsis, with a significant reduction in perfused small vessels at the onset of septic shock. These alterations may play a role in the pathogenesis of septic encephalopathy

Dangers of hyperoxia

Oxygen (O-2) toxicity remains a concern, particularly to the lung. This is mainly related to excessive production of reactive oxygen species (ROS). Supplemental O-2, i.e. inspiratory O-2 concentrations (FIO2) > 0.21 may cause hyperoxaemia (i.e. arterial (a) PO2 > 100 mmHg) and, subsequently, hyperoxia (increased tissue O-2 concentration), thereby enhancing ROS formation. Here, we review the pathophysiology of O-2 toxicity and the potential harms of supplemental O-2 in various ICU conditions. The current evidence base suggests that PaO2 > 300 mmHg (40 kPa) should be avoided, but it remains uncertain whether there is an "optimal level" which may vary for given clinical conditions. Since even moderately supra-physiological PaO2 may be associated with deleterious side effects, it seems advisable at present to titrate O-2 to maintain PaO2 within the normal range, avoiding both hypoxaemia and excess hyperoxaemia.Peer reviewe