| 1. |
- Falkenberg, Cecilia, et al.
(författare)
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A study of the physiological consequences of sympathetic denervation of the heart caused by the arterial switch procedure.
- 2010
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Ingår i: Cardiology in the young. - 1467-1107. ; 20:2, s. 150-8
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The arterial switch operation is the corrective operation for transposition of the great arteries, defined as the combination of concordant atrioventricular and discordant ventriculo-arterial connections, but there have been concerns about silent subendocardial ischaemia on exercise and coronary artery growth. The arterial switch divides the majority of the sympathetic nerves entering the heart; we have studied the effects of coronary flow and sensitivity to catecholamine stimulation in an animal model. METHODS: A total of 10 piglets were operated on cardiopulmonary bypass with section and resuturing of aortic trunk, pulmonary artery and both coronary arteries, with 13 sham-operated controls. After 5-7 weeks of recovery, seven simulated switch survivors and 13 controls were studied. RESULTS: Basal heart rate was significantly higher in switch piglets: in vivo mean (standard deviation) 112 (12) versus sham 100 (10) beats per minute, (p = 0.042); in vitro (Langendorff preparation): 89 (9) versus sham 73 (8) beats per minute (p = 0.0056). In vivo maximal heart rate in response to epinephrine was increased in switch piglets, 209 (13) versus 190 (17) beats per minute (p = 0.044). In vitro dose-response curves to norepinephrine were shifted leftward and upwards (p = 0.0014), with an 80% increase in heart rate induced by 0.095 (0.053) norepinephrine micromole per litre perfusate in switch hearts versus 0.180 (0.035) norepinephrine micromole per litre (p = 0.023). Increase in coronary flow on norepinephrine stimulation and maximal coronary flow were significantly reduced in switch hearts: 0.3 (0.2) versus 0.8 (0.4) millilitre per gram heart weight (p = 0.045) and 2.5 (0.4) versus 3.1 (0.4) millilitre per gram heart (p = 0.030), respectively. CONCLUSIONS: A combination of increased intrinsic heart rate, increased sensitivity to chronotropic actions of norepinephrine, and a decreased maximal coronary flow creates potential for a mismatch between perfusion and energy demands.
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| 2. |
- Marganiec, J., et al.
(författare)
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Coulomb breakup of 17Ne from the viewpoint of nuclear astrophysics
- 2012
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Ingår i: Proceedings of Science. - Proceedings of Science : Sissa. - 1824-8039.
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Konferensbidrag (refereegranskat)abstract
- By the Coulomb breakup of 17Ne, the time-reversed reaction 15O(2p,γ)17Ne has been studied. This reaction might play an important role in the rp process, as a break-out reaction of the hot CNO cycle. The secondary 17Ne ion beam with an energy of 500 MeV/nucleon has been dissociated in a Pb target. The reaction products have been detected with the LAND-R3B experimental setup at GSI. The preliminary differential and integral Coulomb dissociation cross section sCoul has been determined, which then will be converted into a photo-absorption cross section sphoto, and a two-proton radiative capture cross section σcap. Additionally, information about the structure of the 17Ne, a potential two-proton halo nucleus, will be received. The analysis is in progress. © Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike Licence.
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| 3. |
- Berggren, Mattias, et al.
(författare)
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Improved response time with a new miniaturised main-stream multigas monitor.
- 2009
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Ingår i: Journal of clinical monitoring and computing. - : Springer Science and Business Media LLC. - 1573-2614 .- 1387-1307. ; 23:6, s. 355-61
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: For paediatric monitoring and demanding applications such as metabolic monitoring and measurements of functional residual capacity combining gas concentration with flow/volume measurements the performance of side-stream monitors (SSGM) is suboptimal. The objective was to evaluate the performance of a miniaturised mainstream multigas monitor (MSGM) alleged to offer fast response gas monitoring. The MSGM uses infrared technique for measurements of carbon dioxide, nitrous oxide and inhalation agents and fuel cell technique for oxygen monitoring. The MSGM performance was com- pared to a state of the art side-stream monitor in a bench study. METHODS: Response time was measured in two bench study set ups; a high flow oxygen flush to achieve one step change in gas concentrations and during continuous ventilation using a circuit with an oxygen consuming/carbon dioxide producing lung model connected to a ventilator. Averaged tracings from the tested monitors were used for calculation of the 90-10% decline of CO(2), the corresponding 10-90% incline of O(2) and N(2)O and of Isoflurane concentrations in the flush set up and at different inspired O(2) for the O(2) upslope and corresponding CO(2) down- slope during continuous ventilation at different breathing frequencies. Calibration gases with different concentrations of CO(2), O(2) and N(2)O were used for testing of accuracy. RESULTS: The MSGM response time for CO(2) was 96 (88-100) compared to 348 (340-352) ms for the SSGM (P < 0.001). Corresponding response times for O(2) was 108 (76-144), and 432 (360-448) ms (P < 0.001), respectively. At a respiratory rate of 60 BPM the SSGM trace was damped and sinusoidal whereas the MSGM displayed wider amplitude and a square waveform. The deviations from calibration gas values were within clinically acceptable range and linear for all gases over the concentration range studied for both monitors. CONCLUSIONS: The MSGM response time for CO(2) and O(2) was less than 1/3 of the SSGM. The performance of the MSGM was maintained at high breathing frequencies. The accuracy was within clinically acceptable limits for both monitors.
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| 4. |
- Fransson, A-L, et al.
(författare)
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Temperature variation in newborn babies: importance of physical contact with the mother.
- 2005
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Ingår i: Archives of disease in childhood. Fetal and neonatal edition. - : BMJ. - 1359-2998 .- 1468-2052. ; 90:6
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Hypothermia is a major cause of deterioration and death in the neonatal period. Temperature deviations are key signs of illness. OBJECTIVE: To determine normal patterns of temperature variation in newborn babies and the influence of external factors. METHODS: Abdominal and foot skin temperature were continuously recorded in 27 healthy full term babies during the first two days of life and related to the care situation-that is, whether the baby was with the mother or in its cot. The recordings were made using no wires to avoid interference with the care of the neonate. Ambient temperature was close to 23 degrees C during the study period. RESULTS: Mean rectal and abdominal and foot skin temperature were lower on day 1 than day 2. The foot skin temperature was directly related to the care situation, being significantly higher when the baby was with the mother. The abdominal skin temperature was much less influenced by external factors. When the neonates were with their mothers, the mean difference between rectal temperature and abdominal skin temperature was 0.2 degrees C compared with a mean difference between rectal temperature and foot skin temperature of 1.5 degrees C, indicating a positive heat balance. In the cot the corresponding temperature differences were 0.7 degrees C and 7.5 degrees C. A temperature difference between rectal and foot skin temperature of 7-8 degrees C indicates a heat loss close to the maximum for which a neonate can compensate (about 70 W/m2). CONCLUSION: This study emphasises the importance of close physical contact with the mothers for temperature regulation during the first few postnatal days.
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| 5. |
- Hanson, Angela, et al.
(författare)
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Lung aeration during ventilation after recruitment guided by tidal elimination of carbon dioxide and dynamic compliance was better than after end-tidal carbon dioxide targeted ventilation : A computed tomography study in surfactant-depleted piglets
- 2011
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Ingår i: Pediatric Critical Care Medicine. - 1529-7535 .- 1947-3893. ; 12:6, s. E362-E368
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To test the hypothesis that tidal elimination of carbon dioxide and dynamic compliance guided lung recruitment and positive end-expiratory pressure titration in surfactant-depleted piglets result in improved aeration (repeated computed tomography scans) and reduced ventilation pressures compared to those of a control group with conventional end-tidal carbon dioxide targeted ventilation. Design: Prospective animal investigation. Setting: Clinical physiology research laboratory. Subjects: Seventeen saline-lavaged piglets. Interventions: The piglets were initially ventilated at an end-inspiratory pressure of 20 cm H(2)O, a positive end-expiratory pressure of 5 cm H(2)O, and a tidal volume of 10 mL kg(-1) for an end-tidal carbon dioxide target of 30-45 torr followed by 5 mins of ventilation without positive end-expiratory pressure. After this, the control group was ventilated for the same end-tidal carbon dioxide target during the study period. In the recruitment group, the protocol started with an increase of the positive end-expiratory pressure to 15 cm H(2)O. The end-inspiratory pressure was then increased in steps of 3 cm H(2)O to a tidal elimination of carbon dioxide peak/plateau in one recruitment group and further increased in two steps in a second recruitment group. A downward positive end-expiratory pressure titration was followed by continuous dynamic compliance monitoring. The "open lung positive end-expiratory pressure" was set 2 cm H(2)O above the positive end-expiratory pressure at the first dynamic compliance decline and used for a final "open lung ventilation" period. Measurements and Main Results: The recruitment groups showed better aeration, lower ventilatory pressure amplitude, and better dynamic compliance than the control group at the end of the study. Recruitment using airway pressures above the tidal elimination of carbon dioxide peak/plateau did not improve aeration. Using end-tidal carbon dioxide targeted ventilation in the control group restored aeration after the ventilation without positive end-expiratory pressure, but no recruitment or improvement of dynamic compliance was measured. Conclusions: Aeration was significantly better after recruitment and positive end-expiratory pressure titration than in a control group managed by "conventional" end-tidal carbon dioxide targeted ventilation. An increase of the end-inspiratory pressure above the tidal elimination of carbon dioxide peak/plateau did not result in an increased amount of normally aerated lung. A recruitment maneuver resulted in a lower ventilatory amplitude for achieving a target tidal volume and better dynamic compliance at the end of the study period compared to those of the control group.
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| 6. |
- Hanson, Angela, et al.
(författare)
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Recruitment and PEEP level influences long-time aeration in saline-lavaged piglets: an experimental model.
- 2012
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Ingår i: Paediatric anaesthesia. - : Wiley. - 1460-9592 .- 1155-5645. ; 22:11, s. 1072-1079
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: To evaluate aeration/ventilation in saline-lavaged piglets during a 3-h follow-up after a recruitment maneuver (RM)/PEEP titration compared with PEEP 10cmH(2) O without a RM. Background: Lung recruitment and PEEP titration are used to find a PEEP preventing repetitive opening/collapsing of lung. Methods: Twenty-one lung-lavaged piglets, mean age 7weeks and mean weight 10kg; a RM-group and a PEEP10-group, were ventilated at PEEP 5cmH(2) O (baseline) followed by zero PEEP ventilation. In the RM-group, tidal elimination of CO(2) and dynamic compliance (Cdyn) guided recruitment and PEEP titration, respectively. A final 3-h ventilation followed using PEEP 2cmH(2) O above the first decline of Cdyn and end-inspiratory pressure (EIP) for a target tidal volume (V(T) ) of 10ml·kg(-1) . In the PEEP10-group, PEEP 10cmH(2) O without a RM was used during the final 3-h ventilation. CT scans and blood gases were repeated every 30min. Airway pressures, Cdyn and hemodynamics were continuously recorded. Results: Aeration improved without differences between groups. The RM-group PEEP level of 10±0.6cmH(2) O did not differ from the PEEP10-group. Compared to baseline EIP was lower in the RM-group after 3-h ventilation. In both groups, driving pressure (DP) was lower and Cdyn higher than baseline. In the RM-group, final EIP and DP were lower and Cdyn higher than in the PEEP10-group. Conclusions: Both RM/PEEP titration and PEEP elevation resulted in improved aeration without differences between groups at the end point. Lung aeration was achieved at lower EIP and DP and higher Cdyn in the RM-group than in the PEEP10-group.
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| 7. |
- Hanson, Angela, et al.
(författare)
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VTCO2 and dynamic compliance-guided lung recruitment in surfactant-depleted piglets: a computed tomography study.
- 2009
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Ingår i: Pediatric critical care medicine : a journal of the Society of Critical Care Medicine and the World Federation of Pediatric Intensive and Critical Care Societies. - 1529-7535 .- 1947-3893. ; 10:6, s. 687-92
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Using computed tomography (CT) as reference, our primary objectives were to test if maximal tidal elimination of carbon dioxide (VTCO2) could be used as a marker of "optimal recruitment," indicating maximal available lung tissue for gas exchange and if a decrease in dynamic compliance (Cdyn) indicated the beginning of lung collapse during a downward positive end-expiratory pressure (PEEP) titration. DESIGN: Prospective laboratory animal investigation. SETTING: Clinical physiology research laboratory. SUBJECTS: Six piglets undergoing lung lavage. INTERVENTIONS: Saline-lavaged piglets were initially ventilated without PEEP at a tidal volume (VT) of 10 mL/kg followed by baseline ventilation at end-inspiratory pressure (EIP) 25 cm H2O and PEEP 6 cm H2O. PEEP was increased to 12 or 15 cm H2O. Then EIP was increased in steps of 5 cm H2O and the EIP where VTCO2 peaked or leveled off was assumed to define optimally recruited lungs. A downward PEEP titration followed from 12 or 15 to 4 cm H2O in steps of 1 cm H2O. First decline of Cdyn was assumed to define onset of lung collapse. VTCO2 and Cdyn were continuously recorded and CT scans iterated for each change of ventilation. "Open-lung PEEP" was set 2 cm H2O above PEEP at the first Cdyn decline and was used for a final period of "open-lung ventilation." MEASUREMENTS AND MAIN RESULTS: CT images showed recruited lungs at peak VTCO2 and that a minimal amount of normally aerated lung was added by further increase in EIP. Cdyn declined just before CT scans indicated lung collapse. Compared with baseline, the target VT of 10 mL/kg was achieved at lower EIP and pressure amplitude (EIP-PEEP) during the final open-lung ventilation with more normally aerated and fewer collapsed lungs. Cdyn was doubled after recruitment. CONCLUSIONS: The lung recruitment maneuver was effective and lungs optimally recruited at maximal VTCO2. A fall in Cdyn indicated lung collapse during downward PEEP titration as confirmed by CT.
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| 8. |
- Norén, Jörgen G, 1947, et al.
(författare)
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Intubation and mineralization disturbances in the enamel of primary teeth.
- 1993
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Ingår i: Acta odontologica Scandinavica. - 0001-6357. ; 51:5, s. 271-5
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Tidskriftsartikel (refereegranskat)abstract
- This study was undertaken to examine the effects of intubation on the enamel development of primary teeth in children intubated during the first 3 months of life. The teeth of 35 children were examined clinically for signs of defects. Dental enamel defects were seen in 26 (74%) patients; enamel hypoplasia was seen in 15 and enamel hypomineralization in 19 cases. In eight patients both enamel hypoplasia and hypomineralization were found. There was a preponderance of enamel defects in the right maxilla, which supports the hypothesis that an early trauma to mineralizing primary teeth caused by laryngoscope may lead to dental enamel hypoplasia.
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| 9. |
- Romlin, Birgitta S, et al.
(författare)
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Intraoperative thromboelastometry is associated with reduced transfusion prevalence in pediatric cardiac surgery.
- 2011
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Ingår i: Anesthesia and analgesia. - 1526-7598. ; 112:1, s. 30-6
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Tidskriftsartikel (refereegranskat)abstract
- Background: The majority of pediatric cardiac surgery patients receive blood transfusions. We hypothesized that the routine use of intraoperative thromboelastometry to guide transfusion decisions would reduce the overall proportion of patients receiving transfusions in pediatric cardiac surgery. Methods: One hundred pediatric cardiac surgery patients were included in the study. Fifty patients (study group) were prospectively included and compared with 50 procedure- and age-matched control patients (control group). In the study group, thromboelastometry, performed during cardiopulmonary bypass, guided intraoperative transfusions. Intraoperative and postoperative transfusions of packed red blood cells, fresh frozen plasma, platelets, and fibrinogen concentrates, and postoperative blood loss and hemoglobin levels were compared between the 2 groups. Results: The proportion of patients receiving any intraoperative or postoperative transfusion of packed red blood cells, fresh frozen plasma, platelets, or fibrinogen concentrates was significantly lower in the study group than in the control group (32 of 50 [64%] vs 46 of 50 [92%], respectively; P < 0.001). Significantly fewer patients in the study group received transfusions of packed red blood cells (58% vs 78%, P = 0.032) and plasma (14% vs 78%, P < 0.001), whereas more patients in the study group received transfusions of platelets (38% vs 12%, P = 0.002) and fibrinogen concentrates (16% vs 2%, P = 0.015). Neither postoperative blood loss nor postoperative hemoglobin levels differed significantly between the study group and the control group. Conclusions: The results suggest that routine use of intraoperative thromboelastometry in pediatric cardiac surgery to guide transfusions is associated with a reduced proportion of patients receiving transfusions and an altered transfusion pattern.
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| 10. |
- Romlin, Birgitta S, et al.
(författare)
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Moderate superficial hypothermia prolongs bleeding time in humans.
- 2007
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Ingår i: Acta anaesthesiologica Scandinavica. - : Wiley. - 0001-5172 .- 1399-6576. ; 51:2, s. 198-201
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: In vitro and in vivo studies have shown that mild systemic hypothermia influences platelet adhesion and aggregation and coagulation reactions. We wanted to test the hypothesis that mild local hypothermia in healthy volunteers with preserved core temperature increased bleeding time. A secondary aim was to evaluate if local cooling influenced whole blood coagulation measured by thrombelastograph (TEG) in the same setting. METHODS: Bleeding time was measured at the left volar forearm at a baseline skin temperature of 32 degrees C and after cooling to 30 degrees C and 28 degrees C in a water bath. Skin temperature was continuously measured by contact thermistors. Measurements of coagulation by TEG were performed at baseline skin temperature before cooling and after cooling to 28 degrees C skin temperature. Tympanic membrane temperature was continuously measured. RESULTS: Compared with baseline, bleeding time was significantly prolonged at 30 degrees C skin temperature and further prolonged at 28 degrees C skin temperature. No significant differences were measured in any of the TEG parameters. During the procedure, tympanic membrane temperature did not change. CONCLUSION: Lowering the skin temperature from 32 degrees C to 30 degrees C and 28 degrees C with a preserved core temperature more than doubled the bleeding time. Whole blood coagulation measured by TEG was not influenced by the local cooling. In addition to core temperature, local temperature may offer information in understanding the surgical site of bleeding.
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