16 research outputs found
Contribution of High Nature Value farming systems to sustainable livestock production : A case from Finland
Sustainability of livestock production is a highly contested issue in agricultural sustainability discourse. This study aimed to assess the environmental impact of farms using semi-natural grasslands in Finland, or so-called High Nature Value (HNV) farms. We estimated the environmental impact of 11 such farms, including greenhouse gas emissions (GHG), nitrogen (N) balance, land occupation, and carbon storage. We also accounted for unique biodiversity, defined in this study as communities that are dependent on semi-natural grasslands. We compared these to the alternative states of the farms, specifically a hypothetical farm with the same production output but without access to semi natural grasslands. GHG emissions at the farm level (tCO(2eq)/ha) in HNV farms were 64% lower than on the alternative farms; GHG emissions at the product level (tCO(2eq)/t LW) and N balance (N kg/ha) were 31% and 235% lower, respectively. The carbon stocks were 163% higher at farm level. Biodiversity values, indicated by the share of semi-natural grassland in management, ranged from 23% to 83% on HNV farms. Six out of eleven farms would need to increase their arable land occupation by an average of 39% of arable land to fulfil their needs for animal feed if they did not utilize semi-natural grassland. This study contributes to growing evidence that HNV farming systems can support sustainable production by minimising arable land occupation, reducing nutrient loses, and increasing carbon storage while maintaining unique biodiversity.Peer reviewe
Noninvasive Neuromonitoring of Hypothermic Circulatory Arrest in Aortic Surgery
Background and Aims: Circulatory arrest carries a high risk of neurological damage, but modern monitoring methods lack reliability, and is susceptible to the generalized effects of both anesthesia and hypothermia. The objective of this prospective, explorative study was to research promising, reliable, and noninvasive methods of neuromonitoring, capable of predicting neurological outcome after hypothermic circulatory arrest. Materials and Methods: Thirty patients undergoing hypothermic circulatory arrest during surgery of the thoracic aorta were recruited in a single center and over the course of 4 years. Neuromonitoring was performed with a four-channel electroencephalogram montage and a near-infrared spectroscopy monitor. All data were tested off-line against primary neurological outcome, which was poor if the patient suffered a significant neurological complication (stroke, operative death). Results: A poor primary neurological outcome seen in 10 (33%) patients. A majority (63%) of the cases were emergency surgery, and thus, no neurological baseline evaluation was possible. The frontal hemispheric asymmetry of electroencephalogram, as measured by the brain symmetry index, predicted primary neurological outcome with a sensitivity of 79 (interquartile range; 62%-88%) and specificity of 71 (interquartile range; 61%-84%) during the first 6 h after end of circulatory arrest. Conclusion: The hemispheric asymmetry of frontal electroencephalogram is inherently resistant to generalized dampening effects and is predictive of primary neurological outcome. The brain symmetry index provides an easy-to-use, noninvasive neuromonitoring method for surgery of the thoracic aorta and postoperative intensive care.Peer reviewe
A randomized controlled proof-of-concept trial of early sedation management using Responsiveness Index monitoring in mechanically ventilated critically ill patients
INTRODUCTION: Deep sedation is associated with adverse patient outcomes. We recently described a novel sedation-monitoring technology, the Responsiveness Index (RI), which quantifies patient arousal using processed frontal facial EMG data. We explored the potential effectiveness and safety of continuous RI monitoring during early intensive care unit (ICU) care as a nurse decision-support tool. METHODS: In a parallel-group controlled single centre proof of concept trial, patients requiring mechanical ventilation and sedation were randomized via sequential sealed envelopes following ICU admission. Control group patients received hourly clinical sedation assessment and daily sedation holds; the RI monitor was connected but data were concealed from clinical staff. The intervention group received control group care, but RI monitoring was visible and nurses were asked to adjust sedation to maintain patients with an RI>20 whenever possible. Traffic-light colour coding (RI<20, Red; 20–40, Amber; >40, Green) simplified decision-making. The intervention lasted up to 48 hours. Sixteen nurses were interviewed to explore their views of the novel technology. RESULTS: We analysed 74 patients treated per protocol (36 intervention; 38 control). The proportion of patients with RI<20 was identical at the start of monitoring (54 % both groups). Overall, the proportion of time with RI<20 trended to lower values for the intervention group (median 16 % (1–3rd quartile 8–30 %) versus 33 % (10–54 %); P = 0.08); sedation and analgesic use was similar. A post hoc analysis restricted to patients with RI<20 when monitoring started, found intervention patients spent less time with low RI value (16 % (11–45 %) versus 51 % (33–72 %); P = 0.02), cumulative propofol use trended to lower values (median 1090 mg versus 2390 mg; P = 0.14), and cumulative alfentanil use was lower (21.2 mg versus 32.3 mg; P = 0.01). RASS scores were similar for both groups. Sedation related adverse event rates were similar (7/36 versus 5/38). Similar proportions of patients had sedation holds (83 % versus 87 %) and were extubated (47 % versus 44 %) during the intervention period. Nurses valued the objective visible data trends and simple colour prompts, and found RI monitoring a useful adjunct to existing practice. CONCLUSIONS: RI monitoring was safe and acceptable. Data suggested potential to modify sedation decision-making. Larger trials are justified to explore effects on patient-centred outcomes. TRIAL REGISTRATION: NCT01361230 (registered April 19, 2010) ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13054-015-1043-1) contains supplementary material, which is available to authorized users
Responsiveness of the frontal EMG for monitoring the sedation state of critically ill patients
Background. Excessive sedation is associated with adverse patient outcomes during critical illness, and a validated monitoring technology could improve care. We developed a novel method, the responsiveness index (RI) of the frontal EMG. We compared RI data with Ramsay clinical sedation assessments in general and cardiac intensive care unit (ICU) patients.Methods. We developed the algorithm by iterative analysis of detailed observational data in 30 medical–surgical ICU patients and described its performance in this cohort and 15 patients recovering from scheduled cardiac surgery. Continuous EMG data were collected via frontal electrodes and RI data compared with modified Ramsay sedation state assessments recorded regularly by a blinded trained observer. RI performance was compared with EntropyTM across Ramsay categories to assess validity.Results. RI correlated well with the Ramsay category, especially for the cardiac surgery cohort (general ICU patients r¼0.55; cardiac surgery patients r¼0.85, both P,0.0001).Discrimination across all Ramsay categories was reasonable in the general ICU patient cohort [PK¼0.74 (SEM 0.02)] and excellent in the cardiac surgery cohort [PK¼0.92 (0.02)]. Discrimination between ‘lighter’ vs ‘deeper’ (Ramsay 1–3 vs 4–6) was good for general ICU patients [PK¼0.80 (0.02)] and excellent for cardiac surgery patients [PK¼0.96 (0.02)].Performance was significantly better than EntropyTM. Examination of individual cases suggested good face validity.Conclusions. RI of the frontal EMG has promise as a continuous sedation state monitor in critically ill patients. Further investigation to determine its utility in ICU decision-making is warranted
An assessment of the validity of spectral entropy as a measure of sedation statein mechanically ventilated critically ill patients
To assess whether the Entropy Module (GE Healthcare, Helsinki, Finland), a device to measure hypnosis in anesthesia, is a valid measure of sedation state in critically ill patients by comparing clinically assessed sedation state with Spectral Entropy Prospective observational study. Teaching hospital general ICU. 30 intubated, mechanically ventilated patients without primary neurological diagnoses or drug overdose receiving continuous sedation. Monitoring of EEG and fEMG activity via forehead electrodes for up to 72 h and assessments of conscious level using a modified Ramsay Sedation Scale. 475 trained observer assessments were made and compared with concurrent Entropy numbers. Median State (SE) and Response (RE) Entropy values decreased as Ramsay score increased, but wide variation occurred, especially in Ramsay 4–6 categories. Discrimination between different sedation scores [mean (SEM) PK value: RE 0.713 (0.019); SE 0.710 (0.019)] and between lighter (Ramsay 1–3) vs.deeper (Ramsay 4–6) sedation ranges was inadequate [PK: RE 0.750 (0.025); SE 0.748 (0.025)]. fEMG power decreased with increasing Ramsay score but was often significant even at Ramsay 4–6 states. Frequent “on–off” effects occurred for both RE and SE, which were associated with fEMG activity.Values switched from low to high values even in deeply sedated patients. High Entropy values during deeper sedation were strongly associated with simultaneous high relative fEMG powers. Entropy of the frontal EEG does not discriminate sedation state adequately for clinical use in ICU patients. Facial EMG is a major confounder in clinical sedation range
Correlation of EEG spectral entropy with regional cerebral blood flow during sevoflurane and propofol anaesthesia
ENTROPY™ index monitoring, based on spectral entropy of the electroencephalogram, is a promising new method to measure the depth of anaesthesia. We examined the association between spectral entropy and regional cerebral blood flow in healthy subjects anaesthetised with 2%, 3% and 4% end-expiratory concentrations of sevoflurane and 7.6, 12.5 and 19.0 µg.ml-1 plasma drug concentrations of propofol. Spectral entropy from the frequency band 0.8–32 Hz was calculated and cerebral blood flow assessed using positron emission tomography and [15O]-labelled water at baseline and at each anaesthesia level. Both drugs induced significant reductions in spectral entropy and cortical and global cerebral blood flow. Midfrontal-central spectral entropy was associated with individual frontal and whole brain blood flow values across all conditions, suggesting that this novel measure of anaesthetic depth can depict global changes in neuronal activity induced by the drugs. The cortical areas of the most significant associations were remarkably similar for both drugs