[Show abstract][Hide abstract] ABSTRACT: IntroductionUltrasound of the lung and quantification of B-Lines was recently introduced as a novel tool to detect overhydration. In the present study we aimed to evaluate a four region protocol of lung ultrasound to determine the pulmonary fluid status in ventilated patients in the intensive care unit.Methods
Fifty patients underwent both lung ultrasound and transpulmonary thermodilution measurement using the PiCCO-System. An ultrasound score based on number of single and confluent B-Lines per intercostal space was used to quantify pulmonary overhydration.To check for reproducibility the ultrasound pictures were blinded and reassessed by two different intensivists and classified using the same scoring system. Results were compared to other methods of evaluating hydration status, including extravascular lung water index (EVLWI) and intrathoracic blood volume index calculated from transpulmonary thermodilution measurements. Moreover, chest radiographs were assessed regarding signs for pulmonary overhydration and categorized based on a numeric rating scale.ResultsLung water assessment by ultrasound using a simplified protocol showed excellent correlation with EVLWI over a broad range of lung hydration grades and ventilator settings. Correlation of chest radiography and EVLWI was less accurate. No correlation whatsoever was found with central venous pressure measurement.Conclusion
Lung ultrasound is a useful non-invasive tool to predict hydration status in mechanically ventilated patients. The four region protocol is time saving, correlates well to transpulmonary thermodilution measurements and performs markedly better than chest radiography.
Full-text · Article · Feb 2015 · Critical care (London, England)
[Show abstract][Hide abstract] ABSTRACT: 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.
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.
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 24 hour period was 66% and 59% respectively and for the following 16 hour period 68% and 59% (p < 0.01). Outcome prediction by area of rSO2 below a critical threshold of rsO2 = 50% within the first 40 hours yielded 70% specificity and 86% sensitivity for poor outcome.
On average, rSO2 within the first 40 hours after ROSC is significantly lower in patients with poor outcome, but rSO2 ranges largely overlap between outcome groups. Our data indicate limited potential for predicition of poor outcome by frontal brain rSO2 measurements.
[Show abstract][Hide abstract] ABSTRACT: Cerebral and microvascular perfusion is reduced in atrial fibrillation (AF). Maintenance of brain perfusion is important in acute disease and long-term course. Assessment of brain perfusion and oxygenation is difficult in clinical practice. Our study aimed to determine changes in cerebral tissue oxygen saturation (SctO2) with bedside near-infrared spectroscopy (NIRS).METHODS AND RESULTS: Twenty patients (mean age 67.7 ± 10.2 years, 50% men) in whom electrical cardioversion (CV) was successful were prospectively studied. Ten patients (mean age 64.2 ± 7.7 years, 80% men) in whom CV was not successful served as control group. Bilateral SctO2, mean arterial pressure (MAP), arterial oxygen saturation (SaO2), and heart rate were recorded and changes of all parameters before and after CV were compared between the groups. Our results show an increase in SctO2 after successful CV that was significantly higher compared with patients who remained in AF (right SctO2 3.25 ± 2.5 vs. -0.13 ± 0.52%, P = 0.001; left SctO2 4.27 ± 3.56 vs. -0.38 ± 2.4%, P < 0.001). Neither arterial blood pressure nor SaO2 changes differed significantly between the two groups. No correlation could be detected between the significant increase of SctO2 after successful CV and arterial blood pressure, SaO2, or heart rate.CONCLUSION: Cerebral tissue oxygen saturation increases significantly after restoration of sinus rhythm. Near-infrared spectroscopy monitoring can identify changes of SctO2 after successful CV of AF independent from standard monitoring parameters (MAP, SaO2). Near-infrared spectroscopy can be used to detect cerebral oxygen saturation deficits in AF patients or patients at high risk for AF. Clinical applications may include monitoring during ablation procedures and in critical care.
[Show abstract][Hide abstract] ABSTRACT: Background
Mild therapeutic hypothermia alters the validity of a number of parameters currently used to predict neurological outcome after cardiac arrest and resuscitation. Thus, additional parameters are needed to increase certainty of early prognosis in these patients. A promising new approach is the determination of the gray-white-matter ratio (GWR) in cranial computed tomography (CCT) obtained early after resuscitation. It is not known how GWR relates to established outcome parameters such as neuron specific enolase (NSE) or somatosensory evoked potentials (SSEP).
Cardiac arrest patients (n = 98) treated with hypothermia were retrospectively analyzed with respect to the prognostic value of GWR, NSE and SSEP.
A GWR < 1.16 predicted poor outcome with 100% specificity and 38% sensitivity. In 62 patients NSE, SSEP and CCT were available. The sensitivity of poor outcome prediction by both NSE > 97 μg/L and bilateral absent SSEP was 43%. The sensitivity increased to 53% in a multi-parameter approach predicting poor outcome using at least two of the three parameters (GWR, NSE and SSEP).
Our results suggest a strong association of a low GWR with poor outcome following cardiac arrest. Determination of the GWR increases the sensitivity in a multi-parameter approach for prediction of poor outcome after cardiac arrest.
Full-text · Article · Apr 2013 · Scandinavian Journal of Trauma Resuscitation and Emergency Medicine
[Show abstract][Hide abstract] ABSTRACT: Neuron specific enolase (NSE) has repeatedly been evaluated for neurological prognostication in patients after cardiac arrest. However, it is unclear whether current guidelines for NSE cutoff levels also apply to cardiac arrest patients treated with hypothermia. Thus, we investigated the prognostic significance of absolute NSE levels and NSE kinetics in cardiac arrest patients treated with hypothermia.
In a prospective study of 35 patients resuscitated from cardiac arrest, NSE was measured daily for four days following admission. Outcome was assessed at ICU discharge using the CPC score. All patients received hypothermia treatment for 24 hours at 33°C with a surface cooling device according to current guidelines.
The cutoff for absolute NSE levels in patients with unfavourable outcome (CPC 3-5) 72 hours after cardiac arrest was 57 μg/l with an area under the curve (AUC) of 0.82 (sensitivity 47%, specificity 100%). The cutoff level for NSE kinetics in patients with unfavourable outcome (CPC 3-5) was an absolute increase of 7.9 μg/l (AUC 0.78, sensitivity 63%, specificity 100%) and a relative increase of 33.1% (AUC 0.803, sensitivity 67%, specificity 100%) at 48 hours compared to admission.
In cardiac arrest patients treated with hypothermia, prognostication of unfavourable outcome by NSE kinetics between admission and 48 hours after resuscitation may be superior to prognostication by absolute NSE levels.
Full-text · Article · Jan 2012 · Scandinavian Journal of Trauma Resuscitation and Emergency Medicine
[Show abstract][Hide abstract] ABSTRACT: Mild hypothermia treatment (32-34°C) in survivors after cardiac arrest (CA) is clearly recommended by the current guidelines. The effects of cooling procedure towards QT interval have not been evaluated so far outside of case series. In a prospective study 34 consecutive survivors after cardiac arrest were continuously monitored with Holter ECG over the first 48 h.
A total of 34 patients were analysed and received mild therapeutic hypothermia treatment (MTH) according to the current guidelines and irrespective of the initial rhythm. At admission to hospital and in the field in case of OHCA, a 12-lead ECG was performed in all patients.
During cooling the incidence of ventricular tachycardia was low (8.8%) and in none of the patients Torsade de pointes occurred. The QTc interval was within normal range at first patient contact with EMS in the field (440.00 ms; IQR 424.25-476.75; n=17) but during hypothermia treatment the QTc interval was significantly prolonged at 33°C after 24h of cooling (564.47 ms; IQR 512.41-590.00; p=0.0001; n=34) and decreased after end of hypothermia to baseline levels (476.74 ms; 448.71-494.97; p=0.15).
The QTc interval was found to be significantly prolonged during MTH treatment, and some severe prolongations >670 ms were observed, without a higher incidence of life-threatening arrhythmias, especially no Torsade des pointes were detected. However, routine and frequent ECG recording with respect to the QTc interval should become part of any hypothermia standard operation protocol and should be recommended by official guidelines.
[Show abstract][Hide abstract] ABSTRACT: Prehospital induction of therapeutic hypothermia after cardiac arrest may require temperature monitoring in the field. Tympanic temperature is non-invasive and frequently used in clinical practice. Nevertheless, it has not yet been evaluated in patients undergoing mild therapeutic hypothermia (MTH). Therefore, a prospective observational study was conducted comparing three different sites of temperature monitoring during therapeutic hypothermia.
Ten consecutive patients admitted to our medical intensive care unit after out-of-hospital cardiac arrest were included in this study. During MTH, tympanic temperature was measured using a digital thermometer. Simultaneously, oesophageal and bladder temperatures were recorded in a total of 558 single measurements.
Compared with oesophageal temperature, bladder temperature had a bias of 0.019°C (limits of agreement ± 0.61°C (2SD)), and tympanic measurement had a bias of 0.021°C (± 0.80°C). Correlation analysis revealed a high relationship for tympanic versus oesophageal temperature (r = 0.95, p < 0.0001) and also for tympanic versus bladder temperature (r = 0.96, p < 0.0001).
That tympanic temperature accurately indicates both oesophageal and bladder temperatures with a very small discrepancy in patients undergoing MTH after cardiac arrest is demonstrated in this study. Although our results were obtained in the hospital setting, these findings may be relevant for the prehospital application of therapeutic hypothermia as well. In this case, tympanic temperature may provide an easy and non-invasive method for temperature monitoring.
Preview · Article · Jun 2011 · Emergency Medicine Journal
[Show abstract][Hide abstract] ABSTRACT: Therapeutic hypothermia has proved effective in improving outcome in patients after cardiac arrest due to ventricular fibrillation (VF). The benefit in patients with non-VF cardiac arrest is still not defined.
This prospective observational study was conducted in a university hospital setting with historical controls. Between 2002 and 2010 387 consecutive patients have been admitted to the intensive care unit (ICU) after cardiac arrest (control n=186; hypothermia n=201). Of those, in 175 patients the initial rhythm was identified as non-shockable (asystole, pulseless electrical activity) rhythm (control n=88; hypothermia n=87). Neurological outcome was assessed at ICU discharge according to the Pittsburgh cerebral performance category (CPC). A follow-up was completed for all patients after 90 days, a Kaplan-Meier analysis and Cox regression was performed.
Hypothermia treatment was not associated with significantly improved neurological outcome in patients resuscitated from non-VF cardiac arrest (CPC 1-2: hypothermia 27.59% vs control 18.20%, p=0.175). 90-Day Kaplan-Meier analysis revealed no significant benefit for the hypothermia group (log rank test p=0.82), and Cox regression showed no statistically significant improvement.
In this cohort patients undergoing hypothermia treatment after non-shockable cardiac arrest do not benefit significantly concerning neurological outcome. Hypothermia treatment needs to be evaluated in a large multicentre trial of cardiac arrest patients found initially to be in non-shockable rhythms to clarify whether cooling may also be beneficial for other rhythms than VF.
Full-text · Article · Mar 2011 · Emergency Medicine Journal
[Show abstract][Hide abstract] ABSTRACT: Neuron specific enolase (NSE) has been proven effective in predicting neurological outcome after cardiac arrest with a current cut off recommendation of 33 microg/l. However, most of the corresponding studies were conducted before the introduction of mild therapeutic hypothermia (MTH). Therefore we conducted a study investigating the association between NSE and neurological outcome in patients treated with MTH.
In this prospective observational cohort study the data of patients after cardiac arrest receiving MTH (n = 97) were consecutively collected and compared with a retrospective non-hypothermia (NH) group (n = 133). Serum NSE was measured 72 hours after admission to ICU. Neurological outcome was classified according to the Pittsburgh cerebral performance category (CPC 1 to 5) at ICU discharge.
NSE serum levels were significantly lower under MTH compared to NH in univariate analysis. However, in a linear regression model NSE was affected significantly by time to return of spontaneous circulation (ROSC) and ventricular fibrillation rhythm but not by MTH. The model for neurological outcome identified NSE, NSE*MTH (interaction) as well as time to ROSC as significant predictors. Receiver Operating Characteristic (ROC) analysis revealed a higher cutoff value for unfavourable outcome (CPC 3 to 5) with a specificity of 100% in the hypothermia group (78.9 microg/l) compared to the NH group (26.9 microg/l).
Recommended cutoff levels for NSE 72 hours after ROSC do not reliably predict poor neurological outcome in cardiac arrest patients treated with MTH. Prospective multicentre trials are required to re-evaluate NSE cutoff values for the prediction of neurological outcome in patients treated with MTH.
[Show abstract][Hide abstract] ABSTRACT: Therapeutic hypothermia has been proven to be effective in improving neurological outcome in patients after cardiac arrest due to ventricular fibrillation (VF). Data concerning the effect of hypothermia treatment on long-term survival however is limited.
Clinical and outcome data of 107 consecutive patients undergoing therapeutic hypothermia after cardiac arrest due to VF were compared with 98 historical controls. Neurological outcome was assessed at ICU discharge according to the Pittsburgh cerebral performance category (CPC). A Kaplan-Meier analysis of follow-up data concerning mortality after 24 months as well as a Cox-regression to adjust for confounders were calculated.
Neurological outcome significantly improved after mild hypothermia treatment (hypothermia group CPC 1-2 59.8%, control group CPC 1-2 24.5%; p < 0.01). In Kaplan-Meier survival analysis hypothermia treatment was also associated with significantly improved 2-year probability for survival (hypothermia 55% vs. control 34%; p = 0.029). Cox-regression analysis revealed hypothermia treatment (p = 0.031) and age (p = 0.013) as independent predictors of 24-month survival.
Our study demonstrates that the early survival benefit seen with therapeutic hypothermia persists after two years. This strongly supports adherence to current recommendations regarding postresuscitation care for all patients after cardiac arrest due to VF and maybe other rhythms as well.
Full-text · Article · Jan 2010 · Scandinavian Journal of Trauma Resuscitation and Emergency Medicine