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- Lethvall, Sven, 1967, et al.
(författare)
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Tracheal double-lumen ventilation attenuates hypercapnia and respiratory acidosis in lung injured pigs.
- 2004
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Ingår i: Intensive care medicine. - : Springer Science and Business Media LLC. - 0342-4642 .- 1432-1238. ; 30:4, s. 686-92
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Evaluation of ventilatory and circulatory effects with coaxial double-lumen tube ventilation for dead-space reduction as compared with standard endotracheal tube ventilation. DESIGN: Experimental study in a pig model of lung lavage induced acute lung injury. SETTING: University research laboratory. MEASUREMENTS AND RESULTS: Tidal volumes of 6, 8 and 10 ml/kg body weight with a set respiratory rate of 20 breaths per minute were used in a random order with both double-lumen ventilation and standard endotracheal tube ventilation. Measurements of ventilatory and circulatory parameters were obtained after steady state at each experimental stage. With a tidal volume of 6 ml/kg, PaCO(2) was reduced from 10.9 kPa (95% CI 9.0-12.9) with a standard endotracheal tube to 8.2 kPa (95% CI 7.0-9.4) with double-lumen ventilation. This corresponds to a reduction in carbon dioxide levels by 25%. At 6 ml/kg, pH increased from 7.17 (95% CI 7.09-7.24) with a standard endotracheal tube to 7.27 (95% CI 7.21-7.32) with double-lumen ventilation. Tracheal pressure was monitored continuously and no difference between single- or double-lumen ventilation was noted at corresponding levels of ventilation. There was no formation of auto-PEEP. Partial tube obstruction due to secretions was not observed during the experiments. CONCLUSIONS: Coaxial double-lumen tube ventilation is an effective adjunct to reduce technical dead space. It attenuates hypercapnia and respiratory acidosis in a lung injury pig model.
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| 2. |
- Lindgren, Sophie, 1971, et al.
(författare)
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Effectiveness and side effects of closed and open suctioning: an experimental evaluation.
- 2004
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Ingår i: Intensive care medicine. - : Springer Science and Business Media LLC. - 0342-4642 .- 1432-1238. ; 30:8, s. 1630-7
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To compare the effectiveness of closed system suctioning (CSS) and open system suctioning (OSS) and the side effects on gas exchange and haemodynamics, during pressure-controlled ventilation (PCV) or continuous positive airway pressure (CPAP). DESIGN: Bench test and porcine lung injury model. PARTICIPANTS: Twelve bronchoalveolar saline-lavaged pigs. SETTING: Research laboratory in a university hospital. INTERVENTIONS: In a mechanical lung, the efficacy of OSS and CSS with 12 and 14 Fr catheters were compared during volume-control ventilation, PCV, CPAP 0 or 10 cmH(2)O by weighing the suction system before and after aspirating gel in a transparent trachea. Side effects were evaluated in the animals with the same ventilator settings during suctioning of 5, 10 or 20 s duration. MEASUREMENTS AND RESULTS: Suctioning with 12 and 14 Fr catheters was significantly more efficient with OSS (1.9+/-0.1, 2.8+/-0.9 g) and with CSS during CPAP 0 cmH(2)O (1.8+/-0.2, 4.2+/-0.5 g) as compared to CSS during PCV (0.2+/-0.2, 0.8+/-0.3 g) or CPAP 10 cmH(2)O (0.0+/-0.1, 0.7+/-0.4 g), p<0.01 (means +/- SD). OSS and CSS at CPAP 0 cmH(2)O resulted in a marked decrease in SpO(2), mixed venous oxygen saturation and tracheal pressure, p<0.001, but the side effects were considerably fewer during CSS with PCV and CPAP 10 cmH(2)O, p<0.05. CONCLUSIONS: Irrespective of catheter size, OSS and CSS during CPAP 0 cmH(2)O were markedly more effective than CSS during PCV and CPAP 10 cmH(2)O but had worse side effects. However, the side effects lasted less than 5 min in this animal model. Suctioning should be performed effectively when absolutely indicated and the side effects handled adequately.
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| 3. |
- Mercke Odeberg, Johanna, et al.
(författare)
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A pharmacokinetic and pharmacodynamic study of desmopressin: evaluating sex differences and the effect of pre-treatment with piroxicam, and further validation of an indirect response model.
- 2004
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Ingår i: The Journal of pharmacy and pharmacology. - : Oxford University Press (OUP). - 0022-3573 .- 2042-7158. ; 56:11, s. 1389-98
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Tidskriftsartikel (refereegranskat)abstract
- Desmopressin is a synthetic vasopressin analogue mainly used in treatment of diabetes insipidus and nocturia. Studies in rats have revealed a sex difference in the response to a vasopressin infusion, which was diminished after treatment with an NSAID. This study was performed in man to investigate the influence of sex and concomitant treatment of piroxicam on the pharmacokinetics and dynamics of desmopressin, and to validate a previously described indirect response model. Eight healthy males and eight healthy females participated in the trial, which was conducted in a pharmacokinetic (PK) part followed by a pharmacodynamic (PD) part. Desmopressin was administered intravenously as a single dose (PK = dose 2 microg, PD = dose 0.2 microg). Piroxicam was administered to achieve steady state. The pharmacokinetic parameters of desmopressin were estimated and calculated by means of two-compartmental analysis. In the dynamic part a study design based on an oral hydration model was used. Parameters for urine flow and urine osmolality were estimated. Individual estimates of the pharmacokinetic parameters served as input to the indirect response model that subsequently was fitted to urine osmolality data. The pharmacokinetics of desmopressin after a fixed bolus injection was neither influenced by piroxicam nor sex of the subject. The pharmacodynamics of desmopressin showed a sex difference where females exhibited a more pronounced antidiuretic effect than males, which was statistically significant when the effects were submaximal (>4.5 h after dose). The sex differences were diminished after pre-treatment with piroxicam, indicating a prostaglandin PGE(2)-mediated mechanism. The indirect response model was confirmed, although the modelling could not distinguish a sex difference, indicating a limitation of this model compared with traditional descriptive statistics.
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