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- Broomé, Michael, et al.
(författare)
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Pressure-independent cardiac effects of angiotensin II in pigs.
- 2004
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Ingår i: Acta Anaesthesiol Scand. - 0001-6772 .- 1365-201X. ; 182:2, s. 111-9
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Angiotensin II (Ang II) is a potent vasoconstrictor with an important role in the development of cardiovascular disease. Earlier results have shown a positive acute inotropic effect of Ang II in anaesthetized pigs together with significant vasoconstriction. This investigation was designed to study cardiac effects of Ang II, when blood pressure was maintained constant by experimental means. METHODS: Ang II (200 microg h(-1)) was infused in anaesthetized pigs (n = 10) at two different arterial blood pressures, the first determined by the effects of Ang II alone, and the second maintained at baseline blood pressure with nitroprusside. Cardiac systolic and diastolic function was evaluated by analysis of left ventricular pressure-volume relationships. RESULTS: Heart rate, end-systolic elastance (Ees) and pre-load adjusted maximal power (PWRmax EDV(-2)) increased at both blood pressure levels, although less when blood pressure was kept constant with nitroprusside. The time constant for isovolumetric relaxation (tau(1/2)) was prolonged with Ang II alone and shortened with Ang II infused together with nitroprusside. CONCLUSION: Ang II infusion in the pig has inotropic and chronotropic properties independent of arterial blood pressure levels, although the effects seem to be blunted by pharmacological actions of the nitric oxide donor nitroprusside.
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| 4. |
- Fagerberg, Anneli, 1964, et al.
(författare)
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Electrical impedance tomography and heterogeneity of pulmonary perfusion and ventilation in porcine acute lung injury.
- 2009
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Ingår i: Acta anaesthesiologica Scandinavica. - : Wiley. - 1399-6576 .- 0001-5172. ; 53:10, s. 1300-9
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The heterogeneity of pulmonary ventilation (V), perfusion (Q) and V/Q matching impairs gas exchange in an acute lung injury (ALI). This study investigated the feasibility of electrical impedance tomography (EIT) to assess the V/Q distribution and matching during an endotoxinaemic ALI in pigs. METHODS: Mechanically ventilated, anaesthetised pigs (n=11, weight 30-36 kg) were studied during an infusion of endotoxin for 150 min. Impedance changes related to ventilation (Z(V)) and perfusion (Z(Q)) were monitored globally and bilaterally in four regions of interest (ROIs) of the EIT image. The distribution and ratio of Z(V) and Z(Q) were assessed. The alveolar-arterial oxygen difference, venous admixture, fractional alveolar dead space and functional residual capacity (FRC) were recorded, together with global and regional lung compliances and haemodynamic parameters. Values are mean+/-standard deviation (SD) and regression coefficients. RESULTS: Endotoxinaemia increased the heterogeneity of Z(Q) but not Z(V). Lung compliance progressively decreased with a ventral redistribution of Z(V). A concomitant dorsal redistribution of Z(Q) resulted in mismatch of global (from Z(V)/Z(Q) 1.1+/-0.1 to 0.83+/-0.3) and notably dorsal (from Z(V)/Z(Q) 0.86+/-0.4 to 0.51+/-0.3) V and Q. Changes in global Z(V)/Z(Q) correlated with changes in the alveolar-arterial oxygen difference (r(2)=0.65, P<0.05), venous admixture (r(2)=0.66, P<0.05) and fractional alveolar dead space (r(2)=0.61, P<0.05). Decreased end-expiratory Z(V) correlated with decreased FRC (r(2)=0.74, P<0.05). CONCLUSIONS: EIT can be used to assess the heterogeneity of regional pulmonary ventilation and perfusion and V/Q matching during endotoxinaemic ALI, identifying pivotal pathophysiological changes.
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- Fagerberg, Anneli, 1964, et al.
(författare)
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Electrical impedance tomography applied to assess matching of pulmonary ventilation and perfusion in a porcine experimental model.
- 2009
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Ingår i: Critical care (London, England). - : Springer Science and Business Media LLC. - 1466-609X .- 1364-8535. ; 13:2
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Tidskriftsartikel (refereegranskat)abstract
- Electrical impedance tomography (EIT) can be used to measure impedance changes related to the thoracic content of air and blood. Few studies, however, have utilised EIT to make concurrent measurements of ventilation and perfusion. This experimental study was performed to investigate the feasibility of EIT to describe ventilation/perfusion (V/Q) matching after acute changes of pulmonary perfusion and aeration.
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- Fagerberg, Anneli, 1964, et al.
(författare)
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Monitoring pulmonary perfusion by electrical impedance tomography: an evaluation in a pig model.
- 2009
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Ingår i: Acta anaesthesiologica Scandinavica. - : Wiley. - 1399-6576 .- 0001-5172. ; 53:2, s. 152-8
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Electrical impedance tomography (EIT) is a non-invasive technique that generates images of impedance distribution. Changes in the pulmonary content of air and blood are major determinants of thoracic impedance. This study was designed to evaluate EIT in monitoring pulmonary perfusion in a wide range of cardiac output. METHODS: Eight anaesthetised, mechanically ventilated pigs were fitted with a 16-electrode belt at the mid-thoracic level to generate EIT images that were analysed to determine pulse-synchronous systolic changes in impedance (DeltaZ(sys)). Stroke volume (SV) was derived using a pulmonary artery catheter. Reductions in cardiac pre-load, and thus pulmonary perfusion, were induced either by inflating the balloon of a Fogarty catheter positioned in the inferior caval vein or by increasing the positive end-expiratory pressure (PEEP). All measurements were performed in a steady state during a short apnoea. RESULTS: Pulse-synchronous changes in DeltaZ(sys) were easily discernable during apnoea. Balloon inflation reduced SV to 36% of the baseline, with a corresponding decrease in DeltaZ(sys) to 45% of baseline. PEEP reduced SV and DeltaZ(sys) to 52% and 44% of the baseline, respectively. Significant correlations between SV and DeltaZ(sys) were demonstrated during all measurements (rho=0.62) as well as during balloon inflation (rho=0.73) and increased PEEP (rho=0.40). A Bland-Altman comparison of relative changes in SV and DeltaZ(sys) demonstrated a bias of -7%, with 95% limits of agreement at -51% and 36%. CONCLUSIONS: EIT provided beat-to-beat approximations of pulmonary perfusion that significantly correlated to a wide range of SV values achieved during both extra and intrapulmonary interventions to change cardiac output.
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| 7. |
- Frost, Steven A, et al.
(författare)
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Unplanned admission to the intensive care unit in the very elderly and risk of in-hospital mortality.
- 2010
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Ingår i: Critical care and resuscitation. - 1441-2772. ; 12:3, s. 171-6
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Unplanned admission to the intensive care unit has been shown to significantly increase the risk of inhospital mortality. Medical advances and increased expectations have resulted in a greater number of very elderly patients (80 years and over) being admitted to the ICU. The risk of in-hospital death associated with unplanned admission to the ICU in very elderly patients has not been clearly defined. OBJECTIVE: To estimate the risk of in-hospital mortality associated with unplanned admission to the ICU in patients aged 80 years and over. DESIGN, SETTING AND PARTICIPANTS: Retrospective review of an adult intensive care database. The setting was Liverpool Hospital, a large teaching hospital in Sydney, Australia, with a 28-bed ICU that has about 2000 admissions per year. We analysed data on very elderly patients (n = 1680), aged 80 years or more, admitted to the ICU between 1 January 1997 and 31 December 2007. MAIN OUTCOME MEASURES: Baseline risk factors for inhospital mortality. RESULTS: Mortality among patients with unplanned ICU admissions was 47%, compared with 25% in patients with planned admissions (adjusted rate ratio [RR], 1.92 [95% CI, 1.59-2.32]). An estimated 50% of the overall risk of inhospital death among very elderly patients was attributable to a combination of unplanned admission to the ICU, the presence of at least one comorbid condition, acute renal failure and respiratory failure requiring intubation. CONCLUSION: Unplanned admission to the ICU increases the risk of in-hospital mortality in very elderly patients. At least 50% of the risk of in-hospital death in this age group is attributable to a combination of unplanned ICU admission, comorbidity (≥1 comorbid condition), acute renal failure and respiratory failure.
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| 8. |
- Grivans, Christina, 1963, et al.
(författare)
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A Scandinavian survey of drug administration through inhalation, suctioning and recruitment maneuvers in mechanically ventilated patients.
- 2009
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Ingår i: Acta Anaesthesiol Scand. - : Wiley. - 1399-6576. ; 53:6, s. 710-6
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The aim was to describe current practices for drug administration through inhalation, endotracheal suctioning and lung recruitment maneuvers in mechanically ventilated patients in Scandinavian intensive care units (ICUs). METHODS: We invited 161 ICUs to participate in a web-based survey regarding (1) their routine standards and (2) current treatment of ventilated patients during the past 24 h. In order to characterize the patients, the lowest PaO(2) with the corresponding highest FiO(2), and the highest PaO(2) with the corresponding lowest FiO(2) during the 24-h study period were recorded. RESULTS: Eighty-seven ICUs answered and reported 186 patients. Positive end-expiratory pressure (PEEP) levels (cmH(2)O) were 5-9 in 65% and >10 in 31% of the patients. Forty percent of the patients had heated humidification and 50% received inhalation of drugs. Endotracheal suctioning was performed >7 times during the study period in 40% of the patients, of which 23% had closed suction systems. Twenty percent of the patients underwent recruitment maneuvers. The most common recruitment maneuver was to increase PEEP and gradually increase the inspiratory pressure. Twenty-six percent of the calculated PaO(2)/FiO(2) ratios varied >13 kPa for the same patient. CONCLUSION: Frequent use of drug administration through inhalation and endotracheal suctioning predispose to derecruitment of the lungs, possibly resulting in the large variations in PaO(2)/FiO(2) ratios observed during the 24-h study period. Recruitment maneuvers were performed only in one-fifth of the patients during the day of the survey.
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| 9. |
- Hillman, Ken, et al.
(författare)
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Continuum of hospital care: the role of intensive care.
- 2010
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Ingår i: Current opinion in critical care. - 1531-7072. ; 16:5, s. 505-9
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Tidskriftsartikel (refereegranskat)abstract
- This review outlines the way the specialty of intensive care has expanded over the last decade in response to the changing population of hospital patients, being older with more comorbidities and having more complex interventions. The previous disjointed professional and geographical silos, providing patient care, are being challenged and a more patient focussed continuum of care is replacing it.
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| 10. |
- Jonsson, Olof, 1941, et al.
(författare)
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Enhanced post-ischaemic recovery in rabbit kidney after pretreatment with an indeno-indole compound and ascorbate monitored in vivo by 31P magnetic resonance spectroscopy.
- 2003
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Ingår i: Scandinavian Journal of Urology and Nephrology. - 0036-5599. ; 37:6, s. 450-455
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To investigate whether combined pretreatment with lipid- and water-soluble antioxidants gave better restoration of energy phosphates after ischaemia–reperfusion of rabbit kidneys than single pretreatment with a lipid-soluble antioxidant. Material and Methods: Thirteen New Zealand white rabbits were used for the study. Changes in energy phosphates were measured in vivo using volume-selective 31P magnetic resonance spectroscopy. The indeno–indole compound H290/51 was chosen as a lipid-soluble antioxidant and ascorbate as a water-soluble antioxidant. Results: The combined pretreatment led to significantly better restoration of the β-adenosine triphosphate:inorganic phosphate ratio after 60 min of ischaemia and 120 min of reperfusion compared with the single pretreatment. Analyses of blood pressure and blood gas changes showed that the beneficial effect of combined pretreatment was not caused by a better general condition of the animals in that group but by a direct effect on the kidneys. Conclusions: Combined pretreatment with lipid- and water-soluble antioxidants leads to better restoration of energy phosphates in rabbit kidneys subjected to ischaemia–reperfusion compared with single pretreatment with a lipid-soluble antioxidant.
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