EEG for good outcome prediction after cardiac arrest: A multicentre cohort study.

AIM: Assess the prognostic ability of a non-highly malignant and reactive EEG to predict good outcome after cardiac arrest (CA). METHODS: Prospective observational multicentre substudy of the "Targeted Hypothermia versus Targeted Normothermia after Out-of-hospital Cardiac Arrest Trial", also known as the TTM2-trial. Presence or absence of highly malignant EEG patterns and EEG reactivity to external stimuli were prospectively assessed and reported by the trial sites. Highly malignant patterns were defined as burst-suppression or suppression with or without superimposed periodic discharges. Multimodal prognostication was performed 96 h after CA. Good outcome at 6 months was defined as a modified Rankin Scale score of 0-3. RESULTS: 873 comatose patients at 59 sites had an EEG assessment during the hospital stay. Of these, 283 (32%) had good outcome. EEG was recorded at a median of 69 h (IQR 47-91) after CA. Absence of highly malignant EEG patterns was seen in 543 patients of whom 255 (29% of the cohort) had preserved EEG reactivity. A non-highly malignant and reactive EEG had 56% (CI 50-61) sensitivity and 83% (CI 80-86) specificity to predict good outcome. Presence of EEG reactivity contributed (p < 0.001) to the specificity of EEG to predict good outcome compared to only assessing background pattern without taking reactivity into account. CONCLUSION: Nearly one-third of comatose patients resuscitated after CA had a non-highly malignant and reactive EEG that was associated with a good long-term outcome. Reactivity testing should be routinely performed since preserved EEG reactivity contributed to prognostic performance.

[Postcardiac arrest treatment guide]. / Praxisleitfaden für die Postreanimationsbehandlung.

BACKGROUND: Treatment after cardiac arrest has become more complex and interdisciplinary over the last few years. Thus, the clinically active intensive and emergency care physician not only has to carry out the immediate care and acute diagnostics, but also has to prognosticate the neurological outcome. AIM: The different, most important steps are presented by leading experts in the area, taking into account the interdisciplinarity and the currently valid guidelines. MATERIALS AND METHODS: Attention was paid to a concise, practice-oriented presentation. RESULTS AND DISCUSSION: The practical guide contains all important steps from the acute care to the neurological prognosis generation that are relevant for the clinically active intensive care physician.

Outcome prediction in patients after cardiac arrest: a simplified method for determination of gray-white matter ratio in cranial computed tomography.

PURPOSE: Out-of-hospital cardiac arrest is a frequent cause of death in Europe. Hypoxic ischemic encephalopathy (HIE) often develops in initial survivors, and the question of treatment limitation arises in severely affected patients. To establish a poor prognosis with a high level of certainty, the use of a combination of prognostic parameters such as neurological examination, somatosensory evoked potentials, and neuron-specific enolase is common practice. A few recent studies suggest that gray-white matter ratio (GWR) determined from cranial computed tomography (CT) scans is an additional reliable predictor of poor prognosis. The standard GWR determination method involves measurements of 16 different regions of interest (ROIs). We tested whether a simplified method to obtain GWR has equivalent reliability for poor outcome prediction. MATERIALS AND METHODS: We retrospectively analyzed 98 patients after cardiac arrest who had been treated with hypothermia. CT scans were obtained within the first 7 days after cardiac arrest. Neurological outcome was determined at intensive care unit discharge. Four different methods to obtain GWR were compared in a receiver-operating characteristic curve analysis with respect to their prognostic value for poor outcome prediction. RESULTS: The simplest method using only four ROIs (putamen and internal capsule bilaterally) had the same prognostic value compared with the standard method using 16 ROIs. The simplified GWR predicted poor outcome with a sensitivity of 44 % at 100 % specificity. CONCLUSION: Our results indicate that for poor outcome prediction in survivors of cardiac arrest, a simplified GWR determination is feasible and has the same reliability as the complex standard procedure.

Regional cerebral oxygen saturation after cardiac arrest in 60 patients--a prospective outcome study.

INTRODUCTION: Non-invasive near-infrared spectroscopy (NIRS) offers the possibility to determine regional cerebral oxygen saturation (rSO2) in patients with cardiac arrest. Limited data from recent studies indicate a potential for early prediction of neurological outcome. METHODS: Sixty cardiac arrest patients were prospectively enrolled, 22 in-hospital cardiac arrest (IHCA) and 38 out-of-hospital cardiac arrest (OHCA) patients respectively. NIRS of frontal brain was started after return of spontaneous circulation (ROSC) during admission to ICU and was continued until normothermia. Outcome was determined at ICU discharge by the Pittsburgh Cerebral Performance Category (CPC) and 6 months after cardiac arrest. RESULTS: A good outcome (CPC 1-2) was achieved in 23 (38%) patients, while 37 (62%) had a poor outcome (CPC 3-5). Patients with good outcome had significantly higher rSO2 levels (CPC 1-2: rSO2 68%; CPC 3-5: rSO2 58%; p<0.01). For good and poor outcome median rSO2 within the first 24h period was 66% and 59% respectively and for the following 16h period 68% and 59% (p<0.01). Outcome prediction by area of rSO2 below a critical threshold of rsO2=50% within the first 40h yielded 70% specificity and 86% sensitivity for poor outcome. CONCLUSION: On average, rSO2 within the first 40h after ROSC is significantly lower in patients with poor outcome, but rSO2 ranges largely overlap between outcome groups. Our data indicate limited potential for prediction of poor outcome by frontal brain rSO2 measurements.

Use of target temperature management after cardiac arrest in Germany--a nationwide survey including 951 intensive care units.

INTRODUCTION: Target temperature management (TTM) after cardiac arrest is recommended by international guidelines, which have been last updated in 2010. Here we investigate the status of implementation in a nationwide survey in Germany which took place in 2012. METHODS: We conducted a nationwide telephone survey including a total of 951 German intensive care units (ICUs). ICUs were identified by using the online registry for hospitals in Germany. A questionnaire was used for the interview about basic data of the intensive care unit and about details concerning use and implementation of TTM after cardiac arrest. RESULTS: The overall response rate was 91% (865/951). 86% (742/865) of ICUs used TTM after cardiac arrest and implementation peaked in 2010. 95% (702/736) of the ICUs using TTM perform treatment independently of the initial rhythm and 48% (355/738) apply TTM with the use of a feedback device for cooling and controlled re-warming. However, 22% (166/742) still use conventional methods like ice and cold infusion and only 61% (453/742) of the participants provided a written standard operating procedure (SOP). CONCLUSION: With a delay of several years, TTM after cardiac arrest is now implemented in the majority of German ICUs. The moderate proportion of ICUs using SOPs for TTM and feedback-controlled cooling devices indicates the need of further improvement in post cardiac arrest care.

[Neurological chief complaints in an emergency room]. / Neurologische Leitsymptome in einer Notaufnahme.

Neurological chief complaints often lead patients into the emergency room. In order to establish standard emergency workups it is important to know the frequency of neurological chief complaints. Therefore, we performed a retrospective study on 4,132 consecutive neurological patients in the emergency room over a 1-year period. The most frequent chief complaint was headache (20%) followed by motor deficit (13%), vertigo (12%) and epileptic seizure (11%). In conclusion, the neurological workup in the emergency room can be optimized by establishing clinical decision-making rules for the four most frequent chief complaints.

A flow sensitive alternating inversion recovery (FAIR)-MRI protocol to measure hemispheric cerebral blood flow in a mouse stroke model.

Blood flow imaging is an important tool in cerebrovascular research. Mice are of special interest because of the potential of genetic engineering. Magnetic resonance imaging (MRI) provides three-dimensional noninvasive quantitative methods of cerebral blood flow (CBF) imaging, but these MRI techniques have not yet been validated for mice. The authors compared CBF imaging using flow sensitive alternating inversion recovery (FAIR)-MRI and (14)C-Iodoantipyrine (IAP)-autoradiography in a mouse model of acute stroke. Twenty-nine male 129S6/SvEv mice were subjected to filamentous left middle cerebral artery occlusion (MCAo). CBF imaging was performed with (14)C-IAP autoradiography and FAIR-MRI using two different anesthesia protocols, namely intravenous infusion of etomidate or inhalation of isoflurane, which differentially affect perfusion. Using (14)C-IAP autoradiography, the average CBF in ml/(100 g*min) was 160+/-34 (isoflurane, n=5) vs. and 59+/-21 (etomidate, n=7) in the intact hemisphere and 43+/-12 (isoflurane, n=5) vs. 36+/-12 (etomidate, n=7) in the MCAo hemisphere. Using FAIR-MRI, the corresponding average CBFs were 208+/-56 (isoflurane, intact hemisphere, n=7), 84+/-9 (etomidate, intact hemisphere, n=7), 72+/-22 (isoflurane, MCAo hemisphere, n=7) and 48+/-13 (etomidate, MCAo hemisphere, n=7). Regression analysis showed a strong linear correlation between CBF measured with FAIR-MRI and (14)C-IAP autoradiography, and FAIR-MRI overestimated CBF compared to autoradiography. FAIR-MRI provides repetitive quantitative measurements of hemispheric CBF in a mouse model of stroke.

No evidence for early decrease in blood oxygenation in rat whisker cortex in response to functional activation.

Using optical methods through a closed cranial window over the rat primary sensory cortex in chloralose/urethane-anesthetized rats we evaluated the time course of oxygen delivery and consumption in response to a physiological stimulus (whisker deflection). Independent methodological approaches (optical imaging spectroscopy, single fiber spectroscopy, oxygen-dependent phosphorescence quenching) were applied to different modes of whisker deflection (single whisker, full whisker pad). Spectroscopic data were evaluated using different algorithms (constant pathlength, differential pathlength correction). We found that whisker deflection is accompanied by a significant increase of oxygenated hemoglobin (oxy-Hb), followed by an undershoot. An early increase in deoxygenated hemoglobin (deoxy-Hb) proceeded hyperoxygenation when spectroscopic data were analyzed by constant pathlength analysis. However, correcting for the wavelength dependence of photon pathlength in brain tissue (differential pathlength correction) completely eliminated the increase in deoxy-Hb. Oxygen-dependent phosphorescence quenching did not reproducibly detect early deoxygenation. Together with recent fMRI data, our results argue against significant early deoxygenation as a universal phenomenon in functionally activated mammalian brain. Interpreted with a diffusion-limited model of oxygen delivery to brain tissue our results are compatible with coupling between neuronal activity and cerebral blood flow throughout stimulation, as postulated 110 years ago by C. Roy and C. Sherrington (1890, J. Physiol. 11:85--108).

Optic neuropathy in uremia: an interdisciplinary emergency.

Optic neuropathy in uremia is rare. Although the consequences of optic neuropathy-blindness or substantial loss of vision-are devastating, only a few cases have been reported by way of single case reports and case series studies. The reported patients are heterogeneous with regard to the cause of neuropathy. We report the case of a patient with uremic optic neuropathy and summarize the other cases reported in the literature so far. Based on the data available from these reports, we propose a classification system, which includes nonischemic neurotoxic uremic optic neuropathy; ischemic optic neuropathy, more specifically anterior ischemic optic neuropathy; and optic neuropathy as a result of drug side effects, benign intracranial hypertension, and optic neuritis. The immediate institution of dialysis and corticosteroid therapy and correction of anemia and relative hypotension can optimize the chances of visual recovery for these patients. Close collaboration among nephrologists, ophthalmologists, and neurologists is important in this interdisciplinary emergency.

Magnetic resonance imaging of the heart during positive end-expiratory pressure ventilation in normal subjects.

OBJECTIVES: Magnetic resonance imaging was used to assess the effects of ventilation with positive end-expiratory pressure (PEEP) on cardiac volumes, especially on atrial volumes as well as to determine semiquantitative measurements of spatial interactions between heart, lungs and chest. DESIGN: Prospective study with healthy volunteers undergoing mechanical ventilation with different levels of PEEP during magnetic resonance imaging. SETTING: Magnetic resonance unit, Institute of Diagnostic Imaging, Rudolfinerhaus Hospital. SUBJECTS: Twelve healthy volunteers. INTERVENTIONS: Volunteers were imaged, using a multislice-multiphase technique during spontaneous breathing and with PEEP values of 0, 7, and 15 cm H2O. MEASUREMENTS AND MAIN RESULTS: Atrial as well as ventricular volumes, chest diameters, and midventricular contact between the heart and anterior chest wall were determined on transverse-oblique sections. Atrial volumes showed a progressive decline beginning at a PEEP of 7 cm H2O. Diastolic filling of both ventricles was reduced. A PEEP level of 15 cm H2O induced a significant increase in the sagittal-oblique but not in the transverse-oblique chest diameter. PEEP values of 7 and 15 cm H2O shortened the length of the midventricular contact between the heart and anterior chest wall. CONCLUSIONS: Left and right ventricular end-diastolic volumes and stroke volumes decreased significantly during ventilation with PEEP at 15 cm H2O, as did end-systolic atrial volumes. Volume changes in association with changes of chest and heart configuration suggest external cardiac compression by the expanding lungs. Furthermore, this study illustrates the feasibility of magnetic resonance imaging in mechanically ventilated patients.

Atrial natriuretic peptide release in response to different positive end-expiratory pressure levels.

OBJECTIVE: To assess the influence of different positive end-expiratory pressure (PEEP) levels on plasma atrial natriuretic peptide concentrations. DESIGN: Prospective, randomized study. SETTING: Intensive care unit of a university hospital. PATIENTS: Twenty-seven patients who were mechanically ventilated due to acute respiratory failure. INTERVENTION: None. MEASUREMENTS AND MAIN RESULTS: The patients were randomized into three groups: in each group, a defined PEEP level (5, 10, or 15 cm H2O, respectively) was applied, alternating with zero PEEP (0 cm H2O) in consecutive order (reversal experiment). Blood samples for the determination of atrial natriuretic peptide concentrations were drawn from the pulmonary artery and the radial artery catheters. There were no decreases in atrial natriuretic peptide concentrations with a PEEP of 5 cm H2O, but significant decreases could be shown for PEEP values of 10 and 15 cm H2O. The patients of all groups were subjected to PEEP levels of 5, 10, 15, and 20 cm H2O in randomized order (step experiment). The data demonstrated a significant inverse correlation between changes in PEEP levels and changes in plasma atrial natriuretic peptide concentrations. CONCLUSION: The data suggest that the release of atrial natriuretic peptide is influenced by a PEEP of > or = 10 cm H2O, while a PEEP of < or = 5 cm H2O does not disturb this cardiac endocrine function.

Airway management in a case of neck impalement: use of the oesophageal tracheal combitube airway.

A patient presented with neck impalement after a traffic accident. Respiratory arrest demanded immediate tracheal intubation, which was impossible as a wooden splinter had partially obstructed the pharynx and prevented laryngoscopy. An oesophageal tracheal Combitube airway was inserted successfully and the patient's lungs were ventilated adequately until tracheotomy was performed.

Massive upper airway bleeding after thrombolytic therapy: successful airway management with the Combitube.

We present the case of a patient who required immediate intubation because of increasing upper airway bleeding. Endotracheal intubation failed because the glottis could not be visualized. An airway control device designed for cases of difficult emergency intubations was used successfully. This device can be inserted without the use of a laryngoscope.

Influence of age on outcome of mechanically ventilated patients in an intensive care unit.

OBJECTIVE: To assess the influence of age on the outcome of patients receiving prolonged mechanical ventilation. DESIGN: Retrospective study. SETTING: Intensive care unit. PATIENTS: A total of 1,141 patients in our ICU during a 32-month period. A total of 536 patients required mechanical ventilation. After exclusion of 171 patients ventilated for less than 24 hrs after surgery, 365 patients were investigated. MEASUREMENTS AND MAIN RESULTS: Two hundred sixty-six (73%) patients were aged less than 70 yrs; 99 (27%) patients were greater than or equal to 70 yrs. There was no significant difference in mortality rate between the younger and the older age groups. There was no significant influence of other important factors, such as severity of illness, duration of mechanical ventilation, or length of ICU stay. The only factor showing a significant influence on patient outcome was the reason for mechanical ventilation. There were more survivors in the group being ventilated because of ventilatory insufficiency than in the group with oxygenation impairment (57.8% vs. 23.9%, p less than .001). CONCLUSION: An influence of age on the outcome of mechanically ventilated patients in the ICU could not be ascertained in this study.

[Comparison of netilmicin administration once or three times daily in intensive care patients]. / Vergleich der Einmalgabe von Netilmicin mit der Dreimalgabe bei Intensivpatienten.

In a retrospective study once-daily dosage of netilmicin was compared with the thrice-daily regimen in critically ill patients. Netilmicin given once daily for 5 days appeared to be as effective as the multiple dose regimen, with no increase in the incidence of nephrotoxicity.

[Acute upper airway obstruction caused by cervical hematoma as a complication of an internal jugular vein catheter]. / Akute obere Atemwegsobstruktion durch Zervikalhämatom als Komplikation des Vena-jugularis-interna-Katheters.

4 cases of inadvertent puncture of the common carotid artery following unsuccessful puncture of the internal jugular vein leading to a massive cervical hematoma are described. In all cases, acute upper airway obstruction required immediate intubation.

Esophageal tracheal combitube, endotracheal airway, and mask: comparison of ventilatory pressure curves.

The esophageal tracheal Combitube (ETC) is a new airway especially designed for airway maintenance and ventilation in unconscious patients such as those requiring CPR. The ETC may be used as an esophageal obturator or an endotracheal airway. Previous studies yielded a significantly higher mean arterial oxygen tension (PaO2) during ventilation using an ETC in the esophageal position compared to a conventional endotracheal airway (ETA). To investigate this phenomenon, endotracheal and airway opening pressures were examined in 12 patients in randomized order during ventilation with an ETC in the esophageal position, with an ETA, and with a mask, respectively. In this study again the PaO2 was higher with ETC compared to ETA. The following differences in intratracheal pressure and flow could be found for ETC when compared to ETA: smaller rising pressure during inspiration, prolonged expiratory flow time, and formation of a small positive end expiratory pressure (PEEP). These factors may be responsible for the improved oxygen tension with ETC. Comparing mask to ETC ventilation, PaO2 did not differ; however, mean arterial carbon dioxide tension was higher during mask ventilation.

Esophageal tracheal combitube (ETC) for emergency intubation: anatomical evaluation of ETC placement by radiography.

The esophageal tracheal combitube (ETC) is designed for emergency intubation. The ETC is inserted blindly allowing ventilation after either esophageal or endotracheal placement. A special pharyngeal balloon serves to seal the upper airways. In 10 cardiac arrest patients, emergency intubation with the ETC was performed. Blood gas analyses showed adequate ventilation. Radiography proved correct placement of the proximal and distal balloons in accordance with design theory. Hyperinflation experiments documented expansion of the proximal balloon into the oral cavity rather than towards the epiglottis.

Atrial natriuretic peptide decrease during spontaneous breathing with continuous positive airway pressure in volume-expanded healthy volunteers.

We examined the effect of spontaneous breathing with continuous positive airway pressure (CPAP) on the plasma concentrations of immunoreactive (ir) alpha-atrial natriuretic peptide (ANP). In three experiments, each of 11 healthy male volunteers performed CPAP at 20, 10 and 0 cm H2O for 2 h during continuous volume loading. Samples were drawn from a peripheral vein. Plasma concentrations of irANP were determined by a sensitive radioimmunoassay. Significantly lower concentrations of irANP were observed during 20 cm H2O CPAP than at 10 and 0 cm H2O. The concentrations of irANP did not differ significantly when individuals breathing with CPAP at 10 and at 0 cm H2O were compared. Our data suggest that CPAP at 20 cm H2O lowers the release of ANP in volume-expanded subjects. We hypothesize that this phenomenon may contribute to the fluid retention and renal dysfunction observed frequently during high CPAP levels. The decline in plasma concentrations of irANP may be the result of atrial compression by the distended lungs and of reduced venous return to the heart during CPAP.