| 521. |
- Christensen, Steffen, et al.
(författare)
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Three-year mortality among alcoholic patients after intensive care : a population-based cohort study
- 2012
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Ingår i: Critical Care. - : Springer Science and Business Media LLC. - 1364-8535 .- 1466-609X. ; 16:1, s. R5-
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Alcoholic patients comprise a large proportion of patients in intensive care units (ICUs). However, data are limited on the impact of alcoholism on mortality after intensive care. Methods: We conducted a cohort study among 16,848 first-time ICU patients between 2001 and 2007 to examine 30-day and 3-year mortality among alcoholic patients. Alcoholic patients with and without complications of alcohol misuse (for example, alcoholic liver disease) were identified from previous hospital contacts for alcoholism-related conditions or redemption of a prescription for alcohol deterrents. Data on medication use, demographics, hospital diagnoses, and comorbidity were obtained from medical databases. We computed 30-day and 3-year mortality and mortality rate ratios (MRRs) by using Cox regression analysis, controlling for covariates. Results: In total, 1,229 (7.3%) ICU patients were current alcoholics. Among alcoholic patients without complications of alcoholism (n = 785, 4.7% of the cohort), 30-day mortality was 15.9% compared with 19.7% among nonalcoholic patients. Compared with nonalcoholic patients, the adjusted 30-day MRR was 1.04 (95% confidence interval (CI), 0.87 to 1.25). Three-year mortality was 36.2% compared with 40.9% among nonalcoholic patients, corresponding to an adjusted 3-year MRR of 1.16 (95% CI, 1.03 to 1.31). For alcoholic patients with complications (n = 444, 2.6% of the cohort), 30-day mortality was 33.6%, and 3-year mortality was 64.5%, corresponding to adjusted MRRs, with nonalcoholics as the comparator, of 1.64 (95% CI, 1.38 to 1.95) and 1.67 (95% CI, 1.48 to 1.90), respectively. Conclusions: Alcoholic ICU patients with chronic complications of alcoholism have substantially increased 30-day and 3-year mortality. In contrast, alcoholics without complications have no increased 30-day and only slightly increased 3-year mortality.
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| 522. |
- Chu, Jiangtao, et al.
(författare)
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Impact of static pressure on transmembrane fluid exchange in high molecular weight cut off microdialysis
- 2014
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Ingår i: Biomedical microdevices (Print). - : Springer Science and Business Media LLC. - 1387-2176 .- 1572-8781. ; 16:2, s. 301-310
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Tidskriftsartikel (refereegranskat)abstract
- With the interest of studying larger biomolecules by microdialysis (MD), this sampling technique has reached into the ultrafiltration region of fluid exchange, where fluid recovery (FR) has a strong dependence on pressure. Hence in this study, we focus on the fluid exchange across the high molecular weight cut off MD membrane under the influence of the static pressure in the sampling environment. A theoretical model is presented for MD with such membranes, where FR has a linear dependence upon the static pressure of the sample. Transmembrane (TM) osmotic pressure difference and MD perfusion rate decide how fast FR increases with increased static pressure.A test chamber for in vitro MD under static pressure was constructed and validated. It can hold four MD probes under controlled pressurized conditions. Comparison showed good agreement between experiment and theory. Moreover, test results showed that the fluid recovery of the test chamber MD can be set accurately via the chamber pressure, which is controlled by sample injection into the chamber at precise rate. This in vitro system is designed for modelling in vivo MD in cerebrospinal fluid and studies with biological samples in this system may be good models for in vivo MD.
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| 523. |
- Comasco, Erika, et al.
(författare)
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Adipocytokines levels at delivery, functional variation of TFAP2 beta, and maternal and neonatal anthropometric parameters
- 2013
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Ingår i: Obesity. - : Wiley. - 1930-7381 .- 1930-739X. ; 21:10, s. 2130-2137
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVEAdipocytokines participate in the regulation of glucose metabolism and foetal development. The transcription factor activating protein 2B (TFAP2β) has been associated with adipocytokine regulation, and gene variations with type 2 diabetes and obesity. This study investigated associations between maternal TFAP2B variation, adipocytokines levels and maternal and neonatal anthropometric characteristics.DESIGN AND METHODSA population-based sample of women was followed from delivery to six months postpartum. Adiponectin, leptin and interleukin-6 levels at delivery, and maternal as well as neonatal anthropometric variables were assessed. The TFAP2β intron 1 variable number tandem repeat (VNTR) was genotyped.RESULTSMaternal interleukin-6 correlated positively with leptin at delivery, with peripartum weight changes and weight of newborn males, adjusted for potential confounders. Leptin at delivery was associated with TFAP2β intron 1 VNTR genotype, adjusted for confounders, maternal weight and negatively with birth weight among female neonates. A path model suggested a link between TFAP2β genotype, leptin levels and newborn females' weight.CONCLUSIONSThe present results stress a role for the TFAP2 β in adiposity-related conditions and intrauterine growth. The association between neonatal birth weight and maternal adipocytokine levels, together with the observed sex effect, call for further studies on the mechanisms behind neuro-endocrine foetal programming.
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| 524. |
- Crockett, D. C., et al.
(författare)
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Tidal changes in PaO2 and their relationship to cyclical lung recruitment/derecruitment in a porcine lung injury model
- 2019
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Ingår i: British Journal of Anaesthesia. - : ELSEVIER SCI LTD. - 0007-0912 .- 1471-6771. ; 122:2, s. 277-285
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Tidskriftsartikel (refereegranskat)abstract
- Background: Tidal recruitment/derecruitment (R/D) of collapsed regions in lung injury has been presumed to cause respiratory oscillations in the partial pressure of arterial oxygen (PaO2). These phenomena have not yet been studied simultaneously. We examined the relationship between R/D and PaO2 oscillations by contemporaneous measurement of lung-density changes and PaO2. Methods: Five anaesthetised pigs were studied after surfactant depletion via a saline-lavage model of R/D. The animals were ventilated with a mean fraction of inspired O-2 (FiO(2)) of 0.7 and a tidal volume of 10 ml kg(-1) Protocolised changes in pressure-and volume-controlled modes, inspiratory: expiratory ratio (I:E), and three types of breath-hold manoeuvres were undertaken. Lung collapse and PaO2 were recorded using dynamic computed tomography (dCT) and a rapid PaO2 sensor. Results: During tidal ventilation, the expiratory lung collapse increased when I: E <1 [mean (standard deviation) lung collapse = .7 (8.7)%; P<0.05], but the amplitude of respiratory PaO2 oscillations [ 2.2 (0.8) kPa] did not change during the respiratory cycle. The expected relationship between respiratory PaO2 oscillation amplitude and R/D was therefore not clear. Lung collapse increased during breath-hold manoeuvres at end-expiration and end-inspiration (14% vs 0.9-2.1%; P<0.0001). The mean change in PaO2 from beginning to end of breath-hold manoeuvres was significantly different with each type of breath-hold manoeuvre (P<0.0001). Conclusions: This study in a porcine model of collapse-prone lungs did not demonstrate the expected association between PaO2 oscillation amplitude and the degree of recruitment/derecruitment. The results suggest that changes in pulmonary ventilation are not the sole determinant of changes in PaO2 during mechanical ventilation in lung injury.
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| 525. |
- Crockett, Douglas C., et al.
(författare)
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Validating the inspired sinewave technique to measure the volume of the 'baby lung' in a porcine lung-injury model
- 2020
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Ingår i: British Journal of Anaesthesia. - : ELSEVIER SCI LTD. - 0007-0912 .- 1471-6771. ; 124:3, s. 345-353
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Tidskriftsartikel (refereegranskat)abstract
- Background: Bedside lung volume measurement could personalise ventilation and reduce driving pressure in patients with acute respiratory distress syndrome (ARDS). We investigated a modified gas-dilution method, the inspired sinewave technique (IST), to measure the effective lung volume (ELV) in pigs with uninjured lungs and in an ARDS model. Methods: Anaesthetised mechanically ventilated pigs were studied before and after surfactant depletion by saline lavage. Changes in PEEP were used to change ELV. Paired measurements of absolute ELV were taken with IST (ELVIST) and compared with gold-standard measures (sulphur hexafluoride wash in/washout [ELVSF6] and computed tomography (CT) [ELVCT]). Measured volumes were used to calculate changes in ELV (Delta ELV) between PEEP levels for each method (Delta ELVIST, Delta ELVSF6, and Delta ELVCT). Results: The coefficient of variation was <5% for repeated ELVIST measurements (n=13 pigs). There was a strong linear relationship between ELVIST and ELVSF6 in uninjured lungs (r(2)=0.97), and with both ELVSF6 and ELVCT in the ARDS model (r(2)=0.87 and 0.92, respectively). ELVIST had a mean bias of -12 to 13% (95% limits=+/- 17 - 25%) compared with ELVSF6 and ELVCT. Delta ELVIST was concordant with Delta ELVSF6 and Delta ELVCT in 98-100% of measurements, and had a mean bias of -73 to -77 ml (95% limits=+/- 128 - 186 ml) compared with Delta ELVSF6 and -1 ml (95% limits +/- 333 ml) compared with Delta ELVCT. Conclusions: IST provides a repeatable measure of absolute ELV and shows minimal bias when tracking PEEP-induced changes in lung volume compared with CT in a saline-lavage model of ARDS.
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| 526. |
- Cronin, John N, et al.
(författare)
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Dynamic single-slice CT estimates whole-lung dual-energy CT variables in pigs with and without experimental lung injury
- 2019
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Ingår i: Intensive Care Medicine Experimental. - : Springer. - 2197-425X. ; 7:1
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Dynamic single-slice CT (dCT) is increasingly used to examine the intra-tidal, physiological variation in aeration and lung density in experimental lung injury. The ability of dCT to predict whole-lung values is unclear, especially for dual-energy CT (DECT) variables. Additionally, the effect of inspiration-related lung movement on CT variables has not yet been quantified.METHODS: Eight domestic pigs were studied under general anaesthesia, including four following saline-lavage surfactant depletion (lung injury model). DECT, dCT and whole-lung images were collected at 12 ventilatory settings. Whole-lung single energy scans images were collected during expiratory and inspiratory apnoeas at positive end-expiratory pressures from 0 to 20 cmH2O. Means and distributions of CT variables were calculated for both dCT and whole-lung images. The cranio-caudal displacement of the anatomical slice was measured from whole-lung images.RESULTS: Mean CT density and volume fractions of soft tissue, gas, iodinated blood, atelectasis, poor aeration, normal aeration and overdistension correlated between dCT and the whole lung (r2 0.75-0.94) with agreement between CT density distributions (r 0.89-0.97). Inspiration increased the matching between dCT and whole-lung values and was associated with a movement of 32% (SD 15%) of the imaged slice out of the scanner field-of-view. This effect introduced an artefactual increase in dCT mean CT density during inspiration, opposite to that caused by the underlying physiology.CONCLUSIONS: Overall, dCT closely approximates whole-lung aeration and density. This approximation is improved by inspiration where a decrease in CT density and atelectasis can be interpreted as physiological rather than artefactual.
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| 527. |
- Cronin, John N., et al.
(författare)
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Mechanical Ventilation Redistributes Blood to Poorly Ventilated Areas in Experimental Lung Injury*
- 2020
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Ingår i: Critical Care Medicine. - : LIPPINCOTT WILLIAMS & WILKINS. - 0090-3493 .- 1530-0293. ; 48:3, s. E200-E208
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: Determine the intra-tidal regional gas and blood volume distributions at different levels of atelectasis in experimental lung injury. Test the hypotheses that pulmonary aeration and blood volume matching is reduced during inspiration in the setting of minimal tidal recruitment/derecruitment and that this mismatching is an important determinant of hypoxemia.Design: Preclinical study.Setting: Research laboratory.Subjects: Seven anesthetized pigs 28.7 kg (sd, 2.1 kg).Interventions: All animals received a saline-lavage surfactant depletion lung injury model. Positive end-expiratory pressure was varied between 0 and 20 cm H2O to induce different levels of atelectasis.Measurements and Main Results: Dynamic dual-energy CT images of a juxtadiaphragmatic slice were obtained, gas and blood volume fractions within three gravitational regions calculated and normalized to lung tissue mass (normalized gas volume and normalized blood volume, respectively). Ventilatory conditions were grouped based upon the fractional atelectatic mass in expiration (< 20%, 20-40%, and >= 40%). Tidal recruitment/derecruitment with fractional atelectatic mass in expiration greater than or equal to 40% was less than 7% of lung mass. In this group, inspiration-related increase in normalized gas volume was greater in the nondependent (818 mu L/g [95% CI, 729-908 mu L/g]) than the dependent region (149 mu L/g [120-178 mu L/g]). Normalized blood volume decreased in inspiration in the nondependent region (29 mu L/g [12-46 mu L/g]) and increased in the dependent region (39 mu L/g [30-48 mu L/g]). Inspiration-related changes in normalized gas volume and normalized blood volume were negatively correlated in fractional atelectatic mass in expiration greater than or equal to 40% and 20-40% groups (r(2) = 0.56 and 0.40), but not in fractional atelectatic mass in expiration less than 20% group (r(2) = 0.01). Both the increase in normalized blood volume in the dependent region and fractional atelectatic mass in expiration negatively correlated with Pao(2)/Fio(2) ratio (rho = -0.77 and -0.93, respectively).Conclusions: In experimental atelectasis with minimal tidal recruitment/derecruitment, mechanical inspiratory breaths redistributed blood volume away from well-ventilated areas, worsening Pao(2)/Fio(2).
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| 528. |
- Dahl, Michael, et al.
(författare)
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Can a central blood volume deficit be detected by systolic pressure variation during spontaneous breathing?
- 2016
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Ingår i: BMC Anesthesiology. - : Springer Science and Business Media LLC. - 1471-2253 .- 1471-2253. ; 16
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Tidskriftsartikel (refereegranskat)abstract
- Background: Whether during spontaneous breathing arterial pressure variations (APV) can detect a volume deficit is not established. We hypothesized that amplification of intra-thoracic pressure oscillations by breathing through resistors would enhance APV to allow identification of a reduced cardiac output (CO). This study tested that hypothesis in healthy volunteers exposed to central hypovolemia by head-up tilt. Methods: Thirteen healthy volunteers were exposed to central hypovolemia by 45 degrees head-up tilt while breathing through a facemask with 7.5 cmH(2)O inspiratory and/or expiratory resistors. A brachial arterial catheter was used to measure blood pressure and thus systolic pressure variation (SPV), pulse pressure variation and stroke volume variation. Pulse contour analysis determined stroke volume (SV) and CO and we evaluated whether APV could detect a 10 % decrease in CO. Results: During head-up tilt SV decreased form 91 (+/- 46) to 55 (+/- 24) mL (mean +/- SD) and CO from 5.8 (+/- 2.9) to 4.0 (+/- 1.8) L/min (p < 0.05), while heart rate increased (65 (+/- 11) to 75 (+/- 13) bpm; P < 0.05). Systolic pressure decreased from 127 (+/- 14) to 121 (+/- 13) mmHg during head-up tilt, while SPV tended to increase (from 21 (+/- 15)% to 30 (+/- 13) %). Yet during head-up tilt, a SPV >= 37 % predicted a decrease in CO >= 10 % with a sensitivity and specificity of 78 % and 100 %, respectively. Conclusion: In spontaneously breathing healthy volunteers combined inspiratory and expiratory resistors enhance SPV during head-up tilted induced central hypovolemia and allow identifying a 10 % reduction in CO. Applying inspiratory and expiratory resistors might detect a fluid deficit in spontaneously breathing patients.
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| 529. |
- Dahl, Michael K., et al.
(författare)
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Using an expiratory resistor, arterial pulse pressure variations predict fluid responsiveness during spontaneous breathing : an experimental porcine study
- 2009
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Ingår i: Critical Care. - : Springer Science and Business Media LLC. - 1364-8535 .- 1466-609X. ; 13:2, s. R39-
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Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: Fluid responsiveness prediction is difficult in spontaneously breathing patients. Because the swings in intrathoracic pressure are minor during spontaneous breathing, dynamic parameters like pulse pressure variation (PPV) and systolic pressure variation (SPV) are usually small. We hypothesized that during spontaneous breathing, inspiratory and/or expiratory resistors could induce high arterial pressure variations at hypovolemia and low variations at normovolemia and hypervolemia. Furthermore, we hypothesized that SPV and PPV could predict fluid responsiveness under these conditions. METHODS: Eight prone, anesthetized and spontaneously breathing pigs (20 to 25 kg) were subjected to a sequence of 30% hypovolemia, normovolemia, and 20% and 40% hypervolemia. At each volemic level, the pigs breathed in a randomized order either through an inspiratory and/or an expiratory threshold resistor (7.5 cmH2O) or only through the tracheal tube without any resistor. Hemodynamic and respiratory variables were measured during the breathing modes. Fluid responsiveness was defined as a 15% increase in stroke volume (DeltaSV) following fluid loading. RESULTS: Stroke volume was significantly lower at hypovolemia compared with normovolemia, but no differences were found between normovolemia and 20% or 40% hypervolemia. Compared with breathing through no resistor, SPV was magnified by all resistors at hypovolemia whereas there were no changes at normovolemia and hypervolemia. PPV was magnified by the inspiratory resistor and the combined inspiratory and expiratory resistor. Regression analysis of SPV or PPV versus DeltaSV showed the highest R2 (0.83 for SPV and 0.52 for PPV) when the expiratory resistor was applied. The corresponding sensitivity and specificity for prediction of fluid responsiveness were 100% and 100%, respectively, for SPV and 100% and 81%, respectively, for PPV. CONCLUSIONS: Inspiratory and/or expiratory threshold resistors magnified SPV and PPV in spontaneously breathing pigs during hypovolemia. Using the expiratory resistor SPV and PPV predicted fluid responsiveness with good sensitivity and specificity.
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| 530. |
- Dahlin, Andreas P., et al.
(författare)
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Methodological aspects on microdialysis protein sampling and quantification in biological fluids : an in vitro study on human ventricular CSF.
- 2010
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Ingår i: Analytical Chemistry. - : American Chemical Society (ACS). - 0003-2700 .- 1520-6882. ; 82:11, s. 4376-4385
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Tidskriftsartikel (refereegranskat)abstract
- There is growing interest in sampling of protein biomarkers from the interstitial compartment of the brain and other organs using high molecular cutoff membrane microdialysis (MD) catheters. However, recent data suggest that protein sampling across such MD membranes is a highly complex process that needs to be further studied. Here, we report three major improvements for microdialysis sampling of proteins in complex biological matrixes. The improvements in this in vitro study using human ventricular cerebrospinal fluid as the sample matrix include increased fluid recovery control, decreased protein adsorption on the microdialysis membrane and materials, and novel quantitative mass spectrometry analysis. Dextrans in different concentrations and sizes were added to the perfusion fluid. It was found that dextrans with molecular mass 250 and 500 kDa provided a fluid recovery close to 100%. An improved fluid recovery precision could be obtained by self-assembly triblock polymer surface modification of the MD catheters. The modified catheters also delivered a significantly increased extraction efficiency for some of the investigated proteins. The final improvement was to analyze the dialysates with isobaric tagged (iTRAQ) proteomics, followed by tandem mass spectrometric analysis. By using this technique, 48 proteins could be quantified and analyzed with respect to their extraction efficiencies. The novel aspects of microdialysis protein sampling, detection, and quantification in biological fluids presented in this study should be considered as a first step toward better understanding and handling of the challenges associated with microdialysis sampling of proteins. The next step is to optimize the developed methodology in vivo.
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