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T Pasch

Publications and source records attributed to T Pasch.

At least 55 records · Page 3Linked to original sources
PubMed1998

Characterization of rat lung ICAM-1.

OBJECTIVE AND DESIGN: We expressed soluble rat ICAM-1, generated a polyclonal anti-ICAM-1 antibody, and studied ICAM-1 upregulation in lung inflammatory conditions. Bacterial and baculovirus expression systems were employed. MATERIAL: 250 g adult, male Long Evans rats were used. For in vitro studies, rat pulmonary artery endothelial cells (RPAEC), rat alveolar macrophages and aortic rings were stimulated (as described below) and evaluated for ICAM-1 expression. TREATMENT: RPAEC and macrophages were stimulated with lipopolysaccharide (LPS) and recombinant murine tumour necrosis factor alpha (TNFalpha). In vivo immunoglobulin G (IgG) immune complex-induced lung injury was employed. METHODS: Enzyme-linked immunoassay (ELISA) Western and Northern blot analyses and immunohistochemical evaluations were performed. All experiments were done at least in duplicate. Data were analyzed by two-tailed Student's t-test. RESULTS: ICAM-1 expression of RPAEC was time- and dose-dependent, peaking at 6h after LPS-stimulation. LPS and TNFalpha each enhanced ICAM-1 expression on alveolar macrophages (reaching a maximum at 2 h). In IgG immune complex-induced lung injury, ICAM-1 mRNA isolated from whole lung peaked at 4 h, while lung ICAM- I protein peaked at 6 h. CONCLUSIONS: Quantitation of ICAM-1 expression in vitro and in vivo suggests that ICAM-1 plays a central role in two lung inflammatory models. Furthermore, lung ICAM-1 upregulation involves at least two cell types: vascular endothelial cells and alveolar macrophages.

Animals↗
PubMed1998

Assessment of pulmonary mechanics in mechanical ventilation: effects of imprecise breath detection, phase shift and noise.

OBJECTIVE: In mechanical ventilation, the assessment of pulmonary mechanics, mainly of total compliance (Crs), total resistance (Rrs), and intrinsic positive end-expiratory pressure (PEEPint), is clinically important. By using airway pressure (Paw) and flow (V'aw), the least squares fit (LSF) method allows the continuous calculation of these parameters. The objective of this work was to study the influence of imprecise breath detection, phase shift between airway pressure and flow signals, and noise on the determination of Crs, Rrs, and PEEPint. METHODS: Paw and V'aw were mathematically simulated as well as recorded in mechanically ventilated patients. Crs, Rrs, and PEEPint were computed off-line using the LSF method. The boundaries of the breath data window and the phase relationship between Paw and V'aw signals were manipulated and noise was superimposed. RESULTS: Both simulated and patient data gave similar results. Crs and Rrs were not sensitive to imprecise breath detection. If the first portion of the breath was missed, the mean relative error on PEEPint was 20% or 53% when the exact beginning of inspiration was missed by 0.1 or 0.3 sec, respectively. Paw lag of 66 ms with respect to V'aw yielded a relative error of -15 +/- 4% (mean +/- SD) for Rrs, -5 +/- 2% for Crs, and +13 +/- 16% for PEEPint. Paw lead of 66 ms with respect to V'aw yielded a relative error of +5 +/- 4% for Rrs, +7 +/- 3% for Crs, and +14 +/- 18% for PEEPint. Noise had very little impact on the accuracy of Crs, Rrs, and PEEPint. CONCLUSIONS: We conclude that the LSF method allows the assessment of Crs, Rrs, and PEEPint even with high levels of noise in patients with normal lungs provided that Paw and V'aw signals are precisely synchronised and a reliable breath detection algorithm is used.

Adult↗
PubMed1998

The effect of potato starch derived and corn starch derived hydroxyethyl starch on in vitro blood coagulation.

We have compared the effects of progressive in vitro haemodilution (30% and 60%) with potato starch derived hydroxyethyl starch and corn starch derived hydroxyethyl starch on blood coagulation in 80 patients using thrombelastography. Both solutions significantly compromised blood coagulation as evidenced by an increase in coagulation time and decrease in angle alpha, maximum amplitude and coagulation index (p < 0.05). Blood coagulation was more compromised during haemodilution with potato starch derived hydroxyethyl starch as compared with corn starch derived hydroxyethyl starch (p < 0.05). When taking the effect of haemodilution with 0.9% saline into account, haemodilution with both hydroxyethyl starch solutions also augmented clot lysis (p < 0.05), with potato starch derived hydroxyethyl starch having a greater effect than corn starch derived hydroxyethyl starch (p < 0.05). We conclude that potato starch derived hydroxyethyl starch compromises in vitro blood coagulation more than corn starch derived hydroxyethyl starch.

Adult↗
PubMed1998

Perioperative reliability of an on-site prothrombin time assay under different haemostatic conditions.

Perioperative use of laboratory coagulation assays is limited by the delay in obtaining results. The management of haemostasis during major surgical procedures requires rapid and accurate measurement of the prevailing coagulation status. In this prospective study, we have evaluated the reliability of on-site prothrombin time assessed by the portable coagulation monitor CoaguChek-Plus compared with standard laboratory assays during elective non-cardiac surgery. Sixty-two patients were assigned to one of three groups: group A = normal preoperative coagulation where minor intraoperative blood loss is expected; group B = normal preoperative coagulation where major intraoperative blood loss is expected; and group C = preoperative anticoagulation and minor intraoperative blood loss expected. On-site prothrombin time and laboratory prothrombin time showed poor correlation in group A (r2 = 0.24; bias (2 SD) 1.80 (3.34) S) and group B (r2 = 0.30; 1.43 (3.12) S). The correlation in group C was better (r2 = 0.71; 1.41 (1.92) S). We conclude that prothrombin time measured with the CoaguCheck-Plus monitor did not appear to be suitable for the management of haemostasis.

Blood Loss, Surgical↗
PubMed1998

Substantial changes in arterial blood gases during thoracoscopic surgery can be missed by conventional intermittent laboratory blood gas analyses.

UNLABELLED: Substantial and clinically relevant changes in arterial blood gases are likely to occur during thoracoscopic surgery with one-lung ventilation (OLV). We hypothesized that they may be missed when using the conventional intermittent blood gas sampling practice. Therefore, during 30 thoracoscopic procedures with OLV, the sampling intervals between consecutive intermittent laboratory blood gas analyses (BGA) were evaluated with respect to changes of PaO2, PaCO2, and pHa ([H+]) using a continuous intraarterial blood gas monitoring system. Frequency and timing of BGA were based on the clinical judgment of 16 experienced anesthesiologists who were blinded to the continuously measured values. Extreme fluctuations of PaO2 (37-625 mm Hg), PaCO2 (27-56 mm Hg), and pHa (7.24-7.51) were observed by continuous blood gas monitoring. During 63% of all sampling intervals, PaO2 decreased >20% compared with the preceding BGA value, which remained undetected by intermittent analysis. In 10 patients with a continuously measured minimal PaO2 value < or = 60 mm Hg, the preceding BGA overestimated this minimal PaO2 by > 47%. Correspondingly, PaCO2 increases of > 10% were observed in 35% of all sampling intervals, and [H+] increases of > 10% were observed in 24% of all sampling intervals. Because these blood gas changes were not reliably detected by using noninvasive monitoring and their magnitude is not predictable during OLV, intermittent BGA with short sampling intervals is warranted. In critical cases, continuous blood gas monitoring may be helpful. IMPLICATIONS: The magnitude of blood gas changes during thoracoscopic surgery with one-lung ventilation is not predictable and not reliably detected by noninvasive monitoring. Using a continuous intraarterial blood gas monitoring device, we demonstrated that intermittent laboratory blood gas analysis with short sampling intervals is warranted to detect arterial hypoxemia.

Adolescent↗
PubMed1998

Compromised blood coagulation: an in vitro comparison of hydroxyethyl starch 130/0.4 and hydroxyethyl starch 200/0.5 using thrombelastography.

UNLABELLED: We compared the effects of progressive in vitro hemodilution (30% and 60%) on blood coagulation in 80 patients receiving one of two different 6% hydroxyethyl starch (HES) solutions using thrombelastography (TEG). The newly developed solution has a mean molecular weight of 130 kD and a degree of substitution, defined as the average number of hydroxyethyl groups per glucose moiety, of 0.4 (HES 130/0.4); the conventional solution has a mean molecular weight of 200 kD and a degree of substitution of 0.5 (HES 200/0.5). Both HES solutions significantly compromised blood coagulation, as seen by an increase in reaction time and coagulation time and a decrease in angle alpha, maximal amplitude, and coagulation index (all P < 0.05). There was no difference between HES 130/0.4 and HES 200/0.5 diluted blood (P > 0.05 for all TEG variables). When analyzing the intrinsic HES effect by taking hemodilution with 0.9% saline into account, progressive hemodilution with both HES solutions resulted in an increasing clot lysis (P < 0.05 after 60 min). Again, there was no difference between HES 130/0.4 and HES 200/0.5 diluted blood. We conclude that HES 130/ 0.4 and HES 200/0.5 compromise blood coagulation to the same degree. IMPLICATIONS: Progressive in vitro hemodilution using hydroxyethyl starch (HES) compromises blood coagulation. We observed similar effects of a new HES solution with a mean molecular weight of 130 kD and a degree of substitution of 0.4 (HES 130/0.4), compared with the conventional HES 200/0.5.

Blood Coagulation↗
PubMed1998

Anaesthesia for lung volume reduction surgery.

To date, only a few published studies have been concerned with the anaesthesiological aspects of lung volume reduction surgery. This review summarizes the different anaesthetic concepts and offers a general strategy to meet specific requirements. Limitation of peak inspiratory pressure, tolerance of hypercapnia and avoidance of hypoxia during one-lung ventilation, and the immediate postoperative tracheal extubation of these patients, are considered to be crucial. However, many aspects of the procedure and of anaesthesiological management remain to be elucidated.

Journal Article↗
PubMed1998

State-of-the-art blood saving techniques.

Preoperative autologous donation, the use of erythropoietin, acute normovolaemic haemodilution, acceptance of minimal perioperative haemoglobin levels, the use of specific drugs (aprotinin, antifibrinolytics), cell saving and a meticulous surgical technique aimed at minimizing blood loss have all been described as blood saving techniques. Each has proved effective in reducing the need for allogeneic blood transfusions. With an appropriate selection of patients, all techniques can be used efficiently.

Journal Article↗
PubMed1998

Haemodilution tolerance in patients with mitral regurgitation.

Haemodynamic parameters and oxygen consumption were determined in 20 patients with mitral regurgitation before and after a 12 ml.kg-1 isovolaemic exchange of blood for 6% hydroxyethyl starch. During haemodilution, mean (SEM) haemoglobin concentration decreased from 13.0 (0.4) to 10.3 (0.4) g.dl-1 (p = 0.001). With cardiac filling pressures maintained at predilution levels, cardiac index increased from 1.84 (0.08) to 1.94 (0.08) l.min-1.m-2 (p = 0.025) while systemic vascular resistance decreased from 1556 (86) to 1425 (83) dyne.s.cm-5 (p = 0.002) and oxygen extraction increased from 31.7 (1.1) to 37.3 (1.4)% (p = 0.001) resulting in an unchanged oxygen consumption. The haemodynamic response to haemodilution was not affected by the patients' cardiac rhythm, i.e. whether it was sinus rhythm or atrial fibrillation. In conclusion, isovolaemic haemodilution to a haemoglobin of 10.3 g.dl-1 is well tolerated in patients with mitral regurgitation. Compensatory mechanisms include both an increase in cardiac index and an increase in oxygen extraction.

Aged↗
PubMed1998

Hyaluronan induces monocyte chemoattractant protein-1 expression in renal tubular epithelial cells.

Hyaluronan (HA) is a nonsulfated glycosaminoglycan that accumulates in the renal interstitium in immune-mediated kidney diseases. The functional significance of such HA deposition in the kidney has not been elucidated. Several studies have suggested that HA may exhibit proinflammatory effects. Since chemokines such as monocyte chemoattractant protein-1 (MCP-1) play an important role in the recruitment of leukocytes in renal injury, this study tested whether HA and its fragments could promote MCP-1 production by renal parenchymal cells. Mouse cortical tubular cells were stimulated with fragmented HA or with high molecular weight HA (Healon) in vitro and were examined for MCP-1 expression. Fragmented HA, but not Healon, increased MCP-1 mRNA within 30 min with a peak after 2 h. In addition, a 10-fold increase of MCP-1 protein in the supernatant was found after a 6-h stimulation with fragmented HA. The enhanced MCP-1 mRNA and protein expression in response to HA was dose-dependent between 1 and 100 microg/ml. Upregulation of MCP-1 protein production could be blocked by preincubation with actinomycin D or cycloheximide, suggesting that MCP-1 mRNA and protein expression in response to HA are based on de novo synthesis. The HA-stimulated MCP-1 production was also inhibited with anti-CD44 antibodies, suggesting that MCP-1 is upregulated at least in part by signaling through CD44. In summary, fragmented HA markedly stimulates renal tubular MCP-1 production by mechanisms that involve binding to the HA receptor CD44. It is hypothesized that the accumulation of HA in immune renal injury could participate in the recruitment and activation of inflammatory cells in vivo through production of MCP-1.

Animals↗
PubMed1997

Effects of intravenous and oral clonidine on hemodynamic and plasma-catecholamine response due to endotracheal intubation.

STUDY OBJECTIVE: To investigate the effects of intravenous (IV) versus oral clonidine on alterations of heart rate (HR), mean arterial pressure (MAP), cardiac output (CO), and plasma-catecholamines due to endotracheal intubation. DESIGN: Randomized, double-blind, placebo-controlled study. SETTING: University hospital surgery operating room. PATIENTS: 33 ASA physical status I patients were randomly assigned to either receive clonidine 3 micrograms/kg IV immediately prior to anesthesia induction, clonidine 4 micrograms/kg orally 90 minutes prior to anesthesia induction, or placebo. INTERVENTIONS: Insertion of a 14 G cannula in a large cubital vein for the determination of plasma-catecholamines using local anesthesia. Insertion of a radial artery catheter for measuring blood pressure (BP) using local anesthesia. Transthoracic echocardiography determined CO. MEASUREMENTS AND MAIN RESULTS: Heart rate, MAP, CO, and plasma-catecholamine concentrations were measured. Measurements were performed prior to induction, during intubation, and 10 minutes after intubation. During endotracheal intubation, MAP was significantly lower in the IV clonidine group compared with the placebo and the oral clonidine groups. Cardiac output was significantly lower in the IV clonidine group only. In contrast to the placebo group, norepinephrine plasma concentrations did not increase in either clonidine group. Significant alterations of epinephrine plasma concentrations due to intubation were not observed in either group. Hemodynamics after intubation were not impaired by clonidine treatment. CONCLUSIONS: In conclusion, IV clonidine reduced stress response to endotracheal intubation compared with placebo. Oral clonidine at the dose used was less effective in blunting hemodynamic stress response than IV clonidine.

Administration, Oral↗
PubMed1997

Hemocue, an accurate bedside method of hemoglobin measurement?

OBJECTIVE: Evaluate the accuracy of this bedside method to determine hemoglobin (Hb) concentration in general surgery over a wide range of Hb values and to determine potential sources of error. METHODS: Accuracy of Hb measurement using HemoCue (AB Leo Diagnostics, Helsinborg, Sweden) was assessed in 140 surgical blood samples using 7 HemoCue devices in comparison with a CO-Oximeter (IL 482, Instrumentation Laboratory, Lexington, MA). To analyze potential sources of error, packed red cells and fresh frozen plasma were reconstituted to randomized Hb levels of 2-18 g/dL. RESULTS: In the surgical blood samples, the Hb concentration determined by the CO-Oximeter (HbCOOX) ranged from 5.1 to 16.7 g/dL and the Hb concentration measured by HemoCue (HbHC) from 4.7 to 16.0 g/dL. Bias (HbCOOX - HbHC) between HbCOOX and HbHC was 0.6+/-0.6 g/dL (mean +/- SD) or 5.4+/-5.0% (p < 0.001). Also in the reconstituted blood, the bias between HbCOOX and HbHC was significant (0.2+/-0.3 g/dL or 2.1+/-3.2%; p < 0.001). The microcuvette explained 68% of the variability between HbCOOX and HbHC. HemoCue thus underestimates the Hb concentration by 2-5% and exhibits a 8-10 times higher variability with only 86.4% of HbHC being within +/- 10% of HbCOOX. CONCLUSION. Although the mean bias between HbCOOX and HbHC was relatively low, Hb measurement by HemoCue exhibited a significant variability. Loading multiple microcuvettes and averaging the results may increase the accuracy of Hb measurement by HemoCue.

Evaluation Studies as Topic↗
PubMed1997

Haemodynamic effects of pneumoperitoneum in elderly patients with an increased cardiac risk.

We studied the haemodynamic changes induced by pneumoperitoneum (PP) in elderly patients with increased cardiac risk (ASA class III; n = 10; age 72.3 +/- 8.8 years, mean +/- SD, P < 0.05; group 2) and compared the results with patients at normal risk (ASA class I, II; n = 12; age 55.6 +/- 11.8 years; group 1). Thermodilution measurements were performed after induction of general anaesthesia (T1), after onset of PP (T2, intraabdominal pressure 14 mmHg) and after additional 15 degrees head-up tilt (T3). In both groups PP, as compared with T1, induced a significant increase in mean arterial pressure (MAP, mmHg, group 1: 77 +/- 14 to 96 +/- 18, P < 0.05/group 2: 75 +/- 10 to 102 +/- 18, P < 0.01), mean pulmonary artery pressure (MPAP, mmHg: 15 +/- 5 to 22 +/- 4, P < 0.01/18 +/- 3 to 25 +/- 5, P < 0.01), central venous pressure (CVP, mmHg: 7 +/- 2 to 15 +/- 3, P < 0.01/7 +/- 2 to 12 +/- 2, P < 0.01), pulmonary capillary wedge pressure (PCWP, mmHg: 9 +/- 4 to 16.3, P < 0.01/8 +/- 2 to 15 +/- 6, P < 0.01) and in systemic vascular resistance (SVR, dynes s cm-5: 1415 +/- 375 to 1873 +/- 412, P < 0.01/ 1502 +/- 360 to 2067 +/- 647, P < 0.01). Cardiac index (CI, L min-1 m-2: 2.3 +/- 0.3 to 1.9 +/- 0.3, P < 0.05/2.2 +/- 0.4 to 2.2 +/- 0.5 P = 0.76) and oxygen delivery index (DO2I, mL min-1 m-2: 388 +/- 54 to 324 +/- 61, P < 0.05/358 +/- 69 to 353 +/- 82, P = 0.77) decreased in group 1 but not in group 2. Heart rate, stroke Index, pulmonary vascular resistance, arteriovenous oxygen content difference and oxygen consumption index were unchanged. After head-up tilt MAP (mmHg, 92 +/- 15, P < 0.05/ 101 +/- 17, P < 0.01), MPAP (mmHg, 20 +/- 3, P < 0.01/22 +/- 4, P < 0.05), CVP (mmHg, 12 +/- 2, P < 0.01/10 +/- 2, P < 0.01) and PCWP (mmHg, 12 +/- 3, P < 0.05/12 +/- 5, P < 0.05) remained elevated compared with T1 in both groups, SVR (dynes s cm-5, 1575 +/- 372, P = 0.13/1793 +/- 528, P < 0.01) in group 2 only. No complications occurred. The results indicate that PP is associated with significant but relatively benign haemodynamic changes. Anaesthesia for laparoscopic cholecystectomy may be performed safely also in elderly ASA class III patients with increased cardiac risk. An adequate haemodynamic monitoring is recommended.

Aged↗
PubMed1997

Effects of chronic beta-blockade on compensatory mechanisms during acute isovolaemic haemodilution in patients with coronary artery disease.

We have compared compensatory mechanisms during acute isovolaemic haemodilution of 12 ml/kg body weight of blood with hydroxyethyl starch (450,000/0.7) exchange, in non-beta-blocked and beta-blocked patients with coronary artery disease. During haemodilution, mean concentrations of haemoglobin decreased from 12.8 (SEM 0.2) to 10.1 (0.1) g dl-1 (P < 0.01). Only beta-blocked patients had an increase in cardiac index (P < 0.01); in non-beta-blocked patients, cardiac index remained constant. In both groups oxygen extraction increased (P < 0.01), but the increase tended to be greater in non-beta-blocked patients (P = 0.06). Oxygen consumption was maintained in both groups. There were no ECG signs of myocardial ischaemia. We conclude that beta-blocked and non-beta-blocked patients with coronary artery disease tolerated well moderate haemodilution to a haemoglobin value of approximately 10 g dl-1, however, compensatory haemodynamic mechanisms differed fundamentally between the two groups.

Adrenergic beta-Antagonists↗