| 1. |
- Samuelsson, Anders, et al.
(författare)
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Implications for burn shock resuscitation of a new in vivo human vascular microdosing technique (microdialysis) for dermal administration of noradrenaline
- 2012
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Ingår i: Burns. - : Elsevier. - 0305-4179 .- 1879-1409. ; 38:7, s. 975-983
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Skin has a large dynamic capacity for alterations in blood flow, and is therefore often used for recruitment of blood during states of hypoperfusion such as during burn shock resuscitation. However, little is known about the blood flow and metabolic consequences seen in the dermis secondary to the use vasoactive drugs (i.e. noradrenaline) for circulatory support. The aims of this study were therefore: to develop an in vivo, human microdosing model based on dermal microdialysis; and in this model to investigate effects on blood flow and metabolism by local application of noradrenaline and nitroglycerin by the microdialysis system simulating drug induced circulatory support. less thanbrgreater than less thanbrgreater thanMethod: Nine healthy volunteers had microdialysis catheters placed intradermally in the volar surface of the lower arm. The catheters were perfused with noradrenaline 3 or 30 mmol/L and after an equilibrium period all catheters were perfused with nitroglycerine (2.2 mmol/L). Dermal blood flow was measured by the urea clearance technique and by laser Doppler imaging. Simultaneously changes in dermal glucose, lactate, and pyruvate concentrations were recorded. less thanbrgreater than less thanbrgreater thanResults: Noradrenaline and nitroglycerine delivered to the dermis by the microdialysis probes induced large time- and dose-dependent changes in all variables. We particularly noted that tissue glucose concentrations responded rapidly to hypoperfusion but remained higher than zero. Furthermore, vasoconstriction remained after the noradrenaline administration implicating vasospasm and an attenuated dermal autoregulatory capacity. The changes in glucose and lactate by vasoconstriction (noradrenaline) remained until vasodilatation was actively induced by nitroglycerine. less thanbrgreater than less thanbrgreater thanConclusion: These findings, i.e., compromised dermal blood flow and metabolism are particularly interesting from the burn shock resuscitation perspective where noradrenaline is commonly used for circulatory support. The importance and clinical value of the results obtained in this in vivo dermal model in healthy volunteers needs to be further explored in burn-injured patients.
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| 2. |
- Farnebo, Simon, 1972-, et al.
(författare)
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Assessment of blood flow changes in human skin by microdialysis urea clearance
- 2011
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Ingår i: Microcirculation. - : Wiley. - 1073-9688 .- 1549-8719. ; 18:3, s. 198-204
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Forskningsöversikt (refereegranskat)abstract
- Objective: The aim of this study was to evaluate the urea clearance technique for the measurement of drug-induced blood flow changes in human skin, and compare it with two non-invasive techniques: polarization light spectroscopy and laser Doppler perfusion imaging. Methods: Fifteen microdialysis catheters were placed intracutaneously on the volar aspect of the forearms of healthy human subjects, and were perfused with nitroglycerine, noradrenaline, and again nitroglycerine, to induce local tissue hyperaemia, hypoperfusion, and hyperaemia, respectively. Results: Urea clearance, but not the other techniques, detected the changes in blood flow during all three periods of altered flow. The last hyperaemic response was detected by all three methods. Conclusion: Urea clearance can be used as a relatively simple method to estimate blood flow changes during microdialysis of vasoactive substances, in particular when the tissue is preconditioned in order to enhance the contrast between baseline and the responses to the provocations. Our results support that, in the model described, urea clearance was superior to the optical methods as it detected both the increases and decrease in blood flow, and the returns to baseline between these periods.
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| 3. |
- Farnebo, Simon, et al.
(författare)
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Urea Clearance: A New Technique Based on Microdialysis to Assess Liver Blood Flow Studied in a Pig Model of Ischemia/Reperfusion
- 2010
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Ingår i: EUROPEAN SURGICAL RESEARCH. - : S. Karger AG. - 0014-312X .- 1421-9921. ; 45:2, s. 105-112
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Tidskriftsartikel (refereegranskat)abstract
- Delayed detection of ischemia is one of the most feared postoperative complications. Early detection of impaired blood flow and close monitoring of the organ-specific metabolic status may therefore be critical for the surgical outcome. Urea clearance is a new technique for continuous monitoring of alterations in blood flow and metabolic markers with acceptable temporal characteristics. We compare this new microdialysis technique with the established microdialysis ethanol technique to assess hepatic blood flow. Six pigs were used in a liver ischemia/reperfusion injury model. Microdialysis catheters were placed in liver segment IV and all circulation was stopped for 80 min, followed by reperfusion for 220 min. Urea and ethanol clearance was calculated from the dialysate and correlated with metabolic changes. A laser Doppler probe was used as reference of restoration of blood flow. Both urea and ethanol clearance reproducibly depicted changes in liver blood flow in relation to metabolic changes and laser Doppler measurements. The two techniques highly correlated both overall and during the reperfusion phase (r = 0.8) and the changes were paralleled by altered perfusion as recorded by laser Doppler.
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| 4. |
- Hagglof, Elsa, et al.
(författare)
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Long-term survival after intensive care for COVID-19: a nationwide cohort study of more than 8000 patients
- 2023
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Ingår i: Annals of Intensive Care. - : SPRINGER. - 2110-5820. ; 13:1
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Tidskriftsartikel (refereegranskat)abstract
- Background Was it worth it-what is the outcome after the extended ICU (intensive care unit) length of stay for COVID-19 patients? Surprisingly, data on long-term mortality in large cohorts are lacking. We investigate long-term mortality including differences between men and women, as previous studies show that men generally suffer a more severe course of COVID-19 in terms of severity of illness and short-term mortality.Methods Nationwide cohort including all adult COVID-19 patients admitted to Swedish ICUs until August 12, 2022. Primary outcome was 360-day mortality after ICU admission. Logistic regression was used to estimate associations between demographics, comorbidities, clinical characteristics and mortality.Results In total, 8392 patients were included. Median (IQR) age was 63 (52-72) years and the majority (70.1%) were men. Among the 7390 patients with complete 360-day mortality data, 1775 (24.4%) patients died within 30 days, 2125 (28.8%) within 90 days and 2206 (29.8%) within 360 days from ICU admission. 360-day mortality was 27.1% in women and 31.0% in men. Multivariable logistic regression analysis showed increased risk of 360-day mortality in men compared to women (OR: 1.33, 95% CI: 1.17-1.52). Other variables associated with poor 360-day mortality were age, cardiac disease, COPD/asthma, diabetes, immune deficiency, chronic kidney disease, neuromuscular disease, and malignancy.Conclusion This study confirms the increased severity of disease in critically ill men with COVID-19, even in a long-term perspective. However, mortality beyond 90 days was strikingly low, indicating high probability of survival after the acute phase of illness.
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| 5. |
- Zettersten, Erik, et al.
(författare)
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Long-term outcome after intensive care for COVID-19: differences between men and women—a nationwide cohort study
- 2021
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Ingår i: Critical Care. - : Springer Science and Business Media LLC. - 1364-8535 .- 1466-609X. ; 25:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Questions remain about long-term outcome for COVID-19 patients in general, and differences between men and women in particular given the fact that men seem to suffer a more dramatic course of the disease. We therefore analysed outcome beyond 90days in ICU patients with COVID-19, with special focus on differences between men and women. Methods: We identified all patient ≥ 18years with COVID-19 admitted between March 6 and June 30, 2020, in the Swedish Intensive Care Registry. Patients were followed until death or study end-point October 22, 2020. Association with patient sex and mortality, in addition to clinical variables, was estimated using Cox regression. We also performed a logistic regression model estimating factors associated with 90-day mortality. Results: In total, 2354 patients with COVID-19 were included. Four patients were still in the ICU at study end-point. Median follow-up time was 183days. Mortality at 90-days was 26.9%, 23.4% in women and 28.2% in men. After 90days until end of follow-up, only 11 deaths occurred. On multivariable Cox regression analysis, male sex (HR 1.28, 95% CI 1.06–1.54) remained significantly associated with mortality even after adjustments. Additionally, age, COPD/asthma, immune deficiency, malignancy, SAPS3 and admission month were associated with mortality. The logistic regression model of 90-day mortality showed almost identical results. Conclusions: In this nationwide study of ICU patients with COVID-19, men were at higher risk of poor long-term outcome compared to their female counterparts. The underlying mechanisms for these differences are not fully understood and warrant further studies.
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| 6. |
- Zettersten, Erik
(författare)
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Sex and gender aspects on intensive care : access, intensity and outcome
- 2021
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- There is an underlying assumption in society that critically ill patients are admitted to an intensive care unit (ICU) based on their illness severity coupled with their comorbidities, and that other variables are irrelevant. It is therefore troublesome to not fully understand the sexdiscrepancy in the ICU-population; the gender distribution in intensive care units is consistently found to be around 60% men and 40% women. We sought to elucidate the reasons for this discrepancy by constructing five different studies, covering the entire chain from admittance to the ICU until 90 days post intensive care. The overall aim for this thesis is to investigate if there are differences in allocation of intensive care resources depending on whether the patient is a man or a woman. The first two studies aimed at investigating gender differences in the afferent arm, i.e., the access to the ICU. This was done using surveys with fictive patient cases, where the respondent was to decide whether the patient in each case described was in need of ICU care or not. We concluded that in a blinded survey we could not see any differences in admittance to the ICU depending on whether the patient was a man or a woman. Study III is a retrospective cohort study with 8,598 adult patients admitted between 2006 and 2016 to the ICU at Karolinska University Hospital in Stockholm, Sweden. This study explored differences in the efferent arm, i.e., sex- and gender-based differences in discharge from the ICU and mortality after intensive care. We found that women had a higher probability of being discharged from the ICU. There were no differences in 30- or 90-day mortality. In Study IV we used the same cohort as in study III. In this retrospective cohort study, we explored care provided within the ICU, specifically different ICU-typical items, for example mechanical ventilation, vasoactive and inotropic treatment. We concluded that differences in the level of intensive care provided to men and women exist. Given equal severity of illness, men receive more intensive care. Finally, in study V, we investigated differences between men and women regarding care provided in the ICU as well as long-term outcome for all ICU-treated patients with COVID- 19 during the spring of 2020 in Sweden. Male sex was significantly associated with mortality. Additionally, age, COPD/asthma, immune deficiency, malignancy, SAPS 3 and admission month were associated with mortality. In this nationwide study of ICU patients with COVID- 19 we concluded that men were at higher risk of poor long-term outcome compared to women.
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