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| 2. |
- Broome, Michael
(författare)
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MEDIQ CorVascSim
- 2011
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Annan publikation (övrigt vetenskapligt/konstnärligt)
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| 3. |
- Broome, Michael
(författare)
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Simulation of cardiovascular physiology and pathology with CorVascSim : A PC software for advanced education and research
- 2004
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Background and Goal: The rapid development of computer technology makes simulation of cardiovascular physiology and pathology possible. The current work presents a scientifically based cardiovascular model, with a self-explanatory interface. Material and Methods: An electrical analogue of the cardiovascular system including resistances, capacitances and inductances was constructed. The contractile function of the cardiac atria and ventricles are represented by time-varying elastances. Valvular function, pericardial volume, ventricular interaction and intrathoracic pressure are represented by constants and functions, which can interact. Pressures, flows and volumes are recalculated every millisecond and presented on-line as numerical and high-resolution graphics. Results and Discussion: The validity of the simulation models is based on the references (1-4). The software makes it possible to illustrate a great diversity of circulatory pathological findings including systolic and diastolic heart failure, valve diseases, pericardial effusion, arteriosclerosis and effects of changes in intrathoracic pressure. The model is being used to educate doctors and nurses in cardiac surgery, cardiac anaesthesia, and cardiology, but its pedagogical value remains to be validated. Conclusion: Simulation of cardiac physiology and pathology provides a new way to study the heart. Results from simulations can be used in education as well as in interpretation of clinical invasive monitoring, echocardiography and experimental research.
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| 4. |
- Krakau, Karolina, 1968-, et al.
(författare)
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Energy balance and metabolism after severe traumatic brain injury : A pilot study using doubly labelled water
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Objective: To explore the course of energy balance in patients with severe traumatic brain injury, from time of injury until twelve weeks post injury. Method: This prospective desriptive study included six patients with isolated, closed severe traumatic brain injury and an expected hospital stay of ≥2-3 months. Energy balance was calculated from energy intake compared to total energy expenditure measured by continuous indirect calorimetry and doubly labelled water. Clinical and laboratory variables with possible influence on metabolism and nutritional delivery were recorded simultaneously. Intermittent indirect calorimetry measurements were used to differentiate components of the energy expended. Results: Patients were roughly in energy balance while on mechanical ventilation, but in negative energy balance from the 3rd week post injury. The total energy expenditure then increased while the daily energy intake declined. Concurrent with this period were difficulties in retaining enteral and/or parenteral nutrition delivery routes until oral feeding was satisfactory. Nitrogen balance was back to normal at about 1.5 months and the inflammatory period with increased C-reactive protein levels continued for 12 to 58 days from time of injury. During the first and second month post injury, patients lost 8-19% of their initial body weight. Conclusion: Data suggests that negative energy balance after a severe TBI could not only be explained by the elevated metabolic rate and catabolism induced by the trauma, but also by difficulties in securing alternative nutritional routes in the distressed patient.
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| 5. |
- Krakau, Karolina, 1968-, et al.
(författare)
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Prediction of energy expenditure in patients with severe traumatic brain injury : A validation study by use of continuous indirect calorimetry and doubly labelled water
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Objective: The aim was to evaluate the accuracy of methods to predict energy expenditure (EE) in patients with severe traumatic brain injury (TBI). Method: To this prospective descriptive study, a small cohort of patients (n6) with isolated, severe TBI and an expected hospital stay of ≥2-3 months were included. The EE was measured at two intervals: by continuous indirect calorimetry during mechanical ventilation and by doubly labelled water from 3rd to 5th week post injury. Different equations for prediction of EE and a portable monitor, the SenseWear Armband were compared to the measured EE. Result: The majority of methods for predicting EE agreed poorly with the measured EE during indirect calorimetry period. A good agreement was found only with the three Penn-State equations, but two were biased according to Bland Altman analysis. The Penn-State equation from 1998 was the only valid predictive method, with a mean difference per day close to zero (+22 kcal), an excellent agreement (ICC 0.82) with 72% (n54/75) accurately assessed days (±10% of the measured EE) and with all patients within clinically acceptable levels, i.e. ±15% of the measured EE. During doubly labelled water period, observations were too few for any conclusive statement. Conclusion: These data support use of the Penn-State equation from 1998 to estimate EE in patients with severe TBI while on mechanical ventilation.
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| 7. |
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| 8. |
- Lind, Anne-Li, et al.
(författare)
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Affinity Proteomics Applied to Patient CSF Identifies Protein Profiles Associated with Neuropathic Pain and Fibromyalgia
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Objective: Today, there are no biological tests on which to base pain diagnoses, treatment choices or to understand the biological processes underlying and accompanying chronic pain for the individual pain patient. Relevant biological markers would greatly aid in diagnosis and treatment of patients with chronic pain. Our study aimed to find proteins in CSF associated with fibromyalgia and neuropathic pain, two common and poorly understood chronic pain conditions.Methods: We have performed CSF protein profiling of 55 proteins using a 100-plex antibody suspension bead array. We collected, analyzed and compared CSF samples from 25 patients with neuropathic pain (two independent sets, n=14 patients for discovery and n=11 for verification), 40 patients with fibromyalgia and 135 controls without neurological disease from two different populations.Results: We found significant differences in CSF protein levels between patients and controls (p<0.05). Among these proteins, Apolipoprotein C1 (APOC1) was found to be increased in CSF of neuropathic pain patients compared to controls and there was a non-significant trend for increased levels also in fibromyalgia patient CSF. Ectonucleotide pyrophosphatase (ENPP2, Autotaxin) was increased in the CSF of fibromyalgia patients compared to all other groups including neuropathic pain patients. Multivariate analysis revealed partially overlapping and partially distinct CSF profiles in neuropathic pain patients compared with fibromyalgia and controls for several other proteins including angiotensinogen (AGT), prostaglandin-H2 D-isomerase (PTGDS), neurexin-1 (NRXN1), superoxide dismutase 1 (SOD1) and superoxide dismutase 3 (SOD3).Conclusions: Our results, suggest that the CSF protein profiles of neuropathic pain and fibromyalgia patients may be different from each other and from those of controls. CSF levels of APOC1, ENPP2, AGT, PTGDS, NRXN1, SOD1 and SOD3 should be further investigated for their potential to serve as biomarkers of different kinds of pain pathophysiology.
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| 9. |
- Abrahamsson, Pernilla, 1972-, et al.
(författare)
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Comparison between outcome of surface and intraparenchymatous sampling using microdialysis in an experimental liver ischemia model
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Introduction. We recently have shown that samples from MD probes placed on the surface of the heart reflect metabolic events in the myocardium. This new interesting observation challenges us to consider whether surface application of MD applies to other parenchymatous organs and their surfaces. Material and methods. In thirteen anesthetized pigs transient liver ischemia was achieved by occlusion of arterial and venous inflow to the liver. Two probes on liver surface, and two in parenchyma were perfused with a flow rate of 1 µL/min (n=13). An identical set up was used for probes with a flow rate of 2 µL/min (n=9). Samples were collected for every 15 minute period during 60 minutes of baseline, 45 minutes of ischemia and 60 minutes of reperfusion. Lactate, glucose, pyruvate and glycerol were analysed in MD samples. We focused on relative changes in the present paper. Results. There was a strong agreement in relative lactate and glucose levels between probes placed on liver surface and parenchyma. No significant differences in relative changes of lactate and glucose levels were seen between samples from surface probes and probes in liver parenchyma during equilibration, baseline, ischemia or reperfusion with a flow rate of 1 µL/min. Conclusion. MD sampling applied on the liver surface is a new application area for the MD technique, and may be used to monitor liver metabolism both during physiological and pathophysiological conditions.
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| 10. |
- Ahlstrand, Rebecca, 1973-, et al.
(författare)
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High resolution solid-state manometry of the effect of rocuronium on esophagogastric junction integrity
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Background: The pressure in the lower esophageal sphincter (LES) is partly dependent on striated muscles derived from the crural portion of the diaphragm. The effect of neuromuscular blockade on the integrity of the esophagogastric junction is not well studied. We conducted a prospective interventional study to determine the effect of rocuronium on the pressure in the LES and the barrier pressure (LES pressure – intra gastric pressure). We also studied the effect of positive pressure ventilation on the barrier pressure after neuromuscular blockade with rocuronium.Methods: Fourteen patients classified as ASA I or II (aged 18-75 years) who presented for elective surgery (11 cholecystectomy, 3 inguinal hernia) participated in the study. Esophageal manometry was performed after anesthetization with propofol, fentanyl and sevoflurane. After the insertion of a laryngeal mask airway, the patients breathed spontaneously for one minute. Rocuronium was administrated and the patients observed during the onset of apnea and during one minute of apnea and complete neuromuscular blockade. Volume controlled positive pressure ventilation followed.Results: Muscle relaxation with rocuronium showed no significant changes in barrier pressure comparing the pressure immediately before rocuronium administration with the pressure obtained at the time point of 0% TOF. Conversion to positive pressure ventilation did not change the barrier pressure with inspiration or expiration. The greatest decrease in barrier pressure was measured after inducing anesthesia when comparing pressures during inspiration (P< 0.01)
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