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M J Schultz

Publications and source records attributed to M J Schultz.

At least 19 recordsLinked to original sources
PubMed2006

[End-of-life decisions in seriously ill patients: the position of intensive care nurses].

Intensive care units regularly have patients in whom a curative treatment plan is changed to palliative treatment. This does not only concern the medical and technical aspects, but also medical-ethical problems and questions relating to communication and organization. All these play a part in making a correct assessment. It is logical that nurses play an important part in this process as they have the most contact with the patient and his/her family. The optimalization of collaboration between doctors and nurses by means of the mutual exchange of information unique to each different discipline as well as acknowledging one another's talents and skills, forms the basis of good communication and organization concerning end-of-life decisions. It is useful to formalize this collaboration by means of multidisciplinary discussions.

Critical Care↗
PubMed2006

Mechanical ventilation affects alveolar fibrinolysis in LPS-induced lung injury.

The aim of the present study was to determine the effects of mechanical ventilation on alveolar fibrin turnover in lipopolysaccharide (LPS)-induced lung injury. In a randomised controlled trial, Sprague-Dawley rats (n = 61) were allocated to three ventilation groups after intratracheal LPS (Salmonella enteritidis) instillations. Group I animals were subjected to 16 cmH(2)O positive inspiratory pressure (PIP) and 5 cmH(2)O positive end-expiratory pressure (PEEP); group II animals to 26 cmH(2)O PIP and 5 cmH(2)O PEEP; and group III animals to 35 cmH(2)O PIP and 5 cmH(2)O PEEP. Control rats (not mechanically ventilated) received LPS. Healthy rats served as a reference group. Levels of thrombin-antithrombin complex (TATc), D-dimer, plasminogen activator inhibitor (PAI) activity and PAI-1 antigen in bronchoalveolar lavage fluid were measured. LPS-induced lung injury increased TATc, D-dimer and PAI activity and PAI-1 antigen levels versus healthy animals. High pressure-amplitude ventilation increased TATc concentrations. D-dimer concentrations were not significantly raised. Instead, PAI activity increased with the amplitude of the pressure, from 0.7 U.mL(-1) in group I to 3.4 U.mL(-1) in group II and 5.0 U.mL(-1) in group III. There was no change in PAI-1 antigen levels. In conclusion, mechanical ventilation creates an alveolar/pulmonary anti-fibrinolytic milieu in endotoxin-induced lung injury which, at least in part, might be due to an increase in plasminogen activator inhibitor activity.

Animals↗
PubMed2006

Workload and main activities of consultative ICU nurses: long-term experience in a large teaching hospital in the Netherlands.

BACKGROUND: Early recognition and prompt treatment of deteriorating patients outside the intensive care unit (ICU) improves hospital survival. Over the past decade, consultative services have been implemented in many institutions. This service is frequently performed by ICU nurses, while little information is available on the workload and type of activities these ICU nurses actually perform. METHODS: In 1995, a consultative ICU nurse-driven service was introduced in a large teaching hospital in the Netherlands. In this descriptive study, we determined types of consultation, time consumed per visit, and main interventions during these activities. RESULTS: During the study period, 9144 consultations in 4365 patients were performed. While the number of 'scheduled' visits (visits of patients after discharge from the ICU) was reasonably variable during the study period, the number of 'on demand' visits (visits demanded by non-ICU personnel) increased gradually, especially during the first years. At the end of the observation period, approximately half of the visits were 'on demand' in the non-ICU wards. The mean number of consultations per patient dropped gradually over the whole period, from 4.02 in 1996 to 1.54 in 2004. The total workload was approximately half an hour per day; visits were combined with regular activities of the ICU team. Tracheal suctioning was among the most frequent activities during consultation (approximately 90% of all visits). CONCLUSION: Consultative ICU nurses play a growing role in bridging the gap between the ICU and non-ICU departments in our hospital. Workload is acceptable.

APACHE↗
PubMed2004

Cryoablation of benign breast tumors: evolution of technique and technology.

We report on improvements in cryoprobe design and techniques of cryoablation as a minimally invasive alternative to open surgery for the treatment of benign breast tumors. In the study, which was conducted in 12 centers, 124 lesions in 102 patients were monitored for a period of 12 months after cryoablation. Two different treatment techniques were used: Double HI FREEZE and Tailored Freeze. In patients treated with the Tailored Freeze technique significantly better results were recorded 12 months after the procedure: the median reduction in tumor volume was 91%, 73% of all tumors treated were nonpalpable, 84% of lesions less than 2.5 cm in maximum diameter were nonpalpable, and none of the 31 mammograms performed yielded abnormal findings. Patient satisfaction was good to excellent in 92% of the patients. The safety profile of this technique was excellent; all complications were minor. Evolution of cryoablation freezing techniques, coupled with improvements in cryoprobe design, has resulted in significant improvements in both safety and effectiveness.

Adult↗
PubMed2004

Local activation of coagulation and inhibition of fibrinolysis in the lung during ventilator associated pneumonia.

BACKGROUND: Fibrin deposition is a hallmark of pneumonia. To determine the kinetics of alterations in local coagulation and fibrinolysis in relation to ventilator associated pneumonia (VAP), a single centre prospective study of serial changes in pulmonary and systemic thrombin generation and fibrinolytic activity was conducted in patients at risk for VAP. METHODS: Non-directed bronchial lavage (NBL) was performed on alternate days in patients expected to require mechanical ventilation for more than 5 days. A total of 28 patients were studied, nine of whom developed VAP. RESULTS: In patients who developed VAP a significant increase in thrombin generation was observed in the airways, as reflected by a rise in the levels of thrombin-antithrombin complexes in NBL fluid accompanied by increases in soluble tissue factor and factor VIIa concentrations. The diagnosis of VAP was preceded by a decrease in fibrinolytic activity in NBL fluid. Indeed, before VAP was diagnosed clinically, plasminogen activator activity levels in NBL fluid gradually declined, which appeared to be caused by a sharp increase in NBL fluid levels of plasminogen activator inhibitor 1. CONCLUSION: VAP is characterised by a shift in the local haemostatic balance to the procoagulant side, which precedes the clinical diagnosis of VAP.

Blood Coagulation↗
PubMed2004

Disturbed alveolar fibrin turnover during pneumonia is restricted to the site of infection.

Severe infection is associated with profound alterations in the systemic haemostatic balance, with activation of coagulation and suppressed fibrinolysis. Within the alveolar compartment, similar disturbances have been described during pulmonary inflammation. The current authors investigated whether local haemostasis was influenced during ventilator-associated pneumonia (VAP). In five patients with unilateral VAP, bronchoalveolar lavage fluid (BALF) was obtained from both the infected site (as identified on chest radiograph) and the contralateral noninfected lung (with no clinical or radiographic abnormalities). Markers for coagulation and fibrinolysis were compared between infected and noninfected lungs. A total of 10 healthy volunteers and 10 mechanically ventilated patients without pneumonia served as controls. Strong activation of coagulation (high levels of thrombin-antithrombin complexes, soluble tissue factor and factor VIIa) was detected in BALF from infected lungs, compared with that from noninfected lungs and controls. Furthermore, in infected lungs, fibrinolysis was depressed, with high levels of plasminogen activator inhibitor type 1. In conclusion, ventilator-associated pneumonia is characterised by a hypercoagulant state at the site of infection.

Adult↗
PubMed2003

[Percutaneous dilatating tracheostomy in intensive-care patients: technique, indications and complications].

Since tracheal cannulas are increasingly used to wean intensive-care patients from respiratory machines, more doctors and nurses will find themselves having to take care of patients with tracheostomas. Indications for tracheal cannula use include the likelihood of prolonged mechanical ventilation and/or difficult weaning. Percutaneous dilatational tracheotomy is a relatively simple procedure for inserting a tracheal cannula. It is performed using a modified Seldinger technique, carried out under general anaesthesia; use of a bronchoscope during the operation makes the procedure simpler and safer. When it is difficult to pinpoint the source of problems arising in patients fitted with a tracheal cannula, it must always be considered that the cannula might be the cause. Although rare, complications may arise several weeks or months after decanulation, such as stenosis of the trachea, changes in voice and fistula formation between the trachea and skin. A strict surveillance protocol is needed to recognize and treat late complication.

Dilatation↗
PubMed2003

[Mechanical ventilation in acute respiratory distress syndrome (ARDS): lung protecting strategies for improved alveolar recruitment].

For patients with acute respiratory distress syndrome (ARDS) the most important objective of mechanical ventilation is opening and keeping open the alveoli to achieve adequate oxygenation, without further damaging the lungs or negatively affecting the circulation. Alveolar recruitment is achieved by making use of positive end-expiratory pressure (PEEP). The best PEEP level is that with which the largest improvement in oxygen transport and lung compliance is achieved, without a decrease in the stroke volume of the left ventricle. In addition to the usual volume-controlled ventilation with PEEP, pressure-limited ventilation is also possible. In this a preselected pressure is never exceeded, whereas a maximum inspiratory airflow at the start of inspiration provides more opportunity for gaseous exchange. The oxygenation can possibly be further improved by increasing the inspiration-expiration ratio. As a result of the reduced expiratory period the alveoli which tend to collapse at the end of a normal expiration are kept open. Mechanical ventilation with a lower tidal volume decreases mortality. Ventilation in a prone position increases the end-expiratory lung volume and reduces the intrapulmonary shunt and the regional differences in the degree of ventilation. These factors possibly contribute to preventing ventilation-induced lung damage. Administration of natural surfactant during the ventilation of patients with ARDS seems to be a highly promising strategy; the clinical effectiveness still needs to be demonstrated.

Humans↗
PubMed2002

[Immunomodulating strategies in the treatment of sepsis].

Sepsis is associated with the activation of several inflammatory cascades, including the cytokine network and the coagulation system, but it can also be associated with an immunodepressed state. This can lead to a situation in which the septic patient becomes more susceptible to secondary infections. In animal experiments, inhibition of the cytokine cascade by administration of tumour necrosis factor alpha (TNF alpha)-receptors or anti-TNF alpha antibodies has led to reduced mortality, but this has not been confirmed in clinical trials. After the data were pooled, there was a statistically significant decrease in mortality of 3-5%. Treatment with endotoxin antibodies, corticosteroids in high doses, other anti-inflammatory agents and agents designed to eliminate immunodepression generally also did not produce a convincing decrease in mortality. Research on antithrombotic agents has yielded, along with disappointing results with antithrombin III and 'tissue factor pathway inhibitor', one study with a positive result. In septic patients with organ failure who were treated with activated protein C, a coagulation inhibitor, the mortality decreased from 30.8 to 24.7%.

Adjuvants, Immunologic↗
PubMed2002

Lodixanol inhibits exogenous surfactant therapy in rats with acute respiratory distress syndrome.

Optimal alveolar distribution of exogenous surfactant is an important determinant of its beneficial effect. This distribution can be determined by suspending surfactant in a radiological contrast medium before intratracheal instillation, followed by radiological imaging. Iodixanol is reported to be a safe contrast medium that causes no lung injury when instilled intratracheally. In this study, the effects of surfactant suspended in saline were compared with surfactant suspended either in 4:1 saline-iodixanol (64 mg iodine x mL(-1)) or in 1:1 saline-iodixanol (160 mg iodine x mL(-1)), on oxygenation and lung mechanics in a rat model of adult respiratory distress syndrome (ARDS) induced by lung lavage. After the induction of ARDS, surfactant instillation improved oxygenation, total lung volume at inflation with a distending pressure of 35 cmH2O, lung volume at transpulmonary pressure of 5 cmH2O and Gruenwald index. The effects of surfactant suspended in 4:1 saline-iodixanol were similar to those of surfactant alone. However, instillation of surfactant suspended in 1:1 saline-iodixanol resulted in significantly lower values in all measured parameters. Surface tension was the lowest in surfactant suspended in saline alone and addition of iodixanol led to an increase in surface tension in a dose-dependent manner. In conclusion, iodixanol at the higher dose caused an inhibition of the exogenous surfactant effect, characterized as a lack of improvement in oxygen tension in arterial blood, low total lung compliance, volume at 5 cmH2O end-expiration and Gruenwald index. This effect of iodixanol was probably due to its high surface tension, especially if a high concentration was used. Surfactant suspended in a lower concentration of iodixanol seems a better alternative, allowing for radiological imaging of the distribution of surfactant when intratracheally instilled.

Animals↗
PubMed2001

Mice lacking the multidrug resistance protein 1 are resistant to Streptococcus pneumoniae-induced pneumonia.

Leukotrienes (LTs) are considered important for antibacterial defense in the lung. Multidrug resistance protein 1 (mrp1) is a transmembrane protein responsible for the cellular extrusion of LTC(4). To determine the role of mrp1 in host defense against pneumonia, mrp1(-/-) and wild-type mice were intranasally inoculated with Streptococcus pneumoniae. mrp1(-/-) mice displayed a diminished outgrowth of pneumococci in lungs and a strongly reduced mortality. These findings were related to an effect of mrp1 on LT metabolism, because survival was similar in mrp1(-/-) and wild-type mice treated with the 5-lipoxygenase-activating protein inhibitor MK-886. Although LTC(4) levels remained low in the bronchoalveolar lavage fluid of mrp1(-/-) mice, LTB(4) concentrations were higher than in wild-type mice. These elevated LTB(4) concentrations were important for the relative protection of mrp1(-/-) mice, because the LTB(4) antagonist LTB(4)-dimethyl amide abolished their survival advantage. In vitro experiments suggested that the intracellullar accumulation of LTC(4) in mrp1(-/-) mice results in product inhibition of LTC(4)-synthase, diminishing substrate competition between LTA(4)-hydrolase (which yields LTB(4)) and LTC(4)-synthase for the available LTA(4). We conclude that mrp1(-/-) mice are resistant against pneumococcal pneumonia by a mechanism that involves increased release of LTB(4). These results identify mrp1 as a novel target for adjunctive therapy in pneumonia.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2001

p38 mitogen-activated protein kinase inhibition increases cytokine release by macrophages in vitro and during infection in vivo.

p38 mitogen-activated protein kinase (MAPK) has been suggested as a mediator of cytokine release and is currently being targeted for anti-inflammatory therapy. However, experimental data are contradictory and lack sufficient affirmation in vivo. We tested the effect of p38 MAPK inhibition in several cell types and in different murine models of infectious disease. We observed that most cell types react to p38 MAPK inhibition with diminished cytokine release, but that this treatment induced increased cytokine release in macrophages. Furthermore, we observed increased cytokine production in mouse models of pneumococcal pneumonia and tuberculosis accompanied by severely reduced bacterial clearance. This apparent inefficacy of p38 MAPK inhibition in reducing cytokine release in infectious disease, as well as its immune-compromising action, suggest that targeting p38 MAPK may not be a suitable anti-cytokine strategy in patients with such disease or at risk for infection.

Animals↗
PubMed2001

Pharmacokinetic-pharmacodynamic modeling of the inhibitory effect of erythromycin on tumour necrosis factor-alpha and interleukin-6 production.

Erythromycin inhibits the production of tumour necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL6) induced by heat-killed Streptococcus pneumoniae in human whole blood ex-vivo. The objective of the present study was to determine and characterize the concentration-effect relationship of this phenomenon in order to predict its possible clinical relevance. Six healthy volunteers received a single intravenous dose of 1000 mg erythromycin. Blood samples were obtained up to 4 h after drug administration. Samples were assayed for erythromycin concentrations and (after heat-killed Streptococcus pneumoniae stimulation) for TNF-alpha and IL6 concentrations. Effect vs. time data from individual subjects were fitted to the indirect response model with an Emax concentration-effect relationship. Simulations of these effects were performed for therapeutic intravenous and oral erythromycin dosage regimens. The geometric means of the values of Kin, Kout and EC50 were 15.4 microg/h, 0.82/h, 9.4 mg/L for TNF-alpha and 321 microg/h, 2.02/h, 18.3 mg/L for IL6. Simulations revealed a maximal inhibition of TNF-alpha concentrations of 35%, 50%, 16% and 27% at erythromycin dosages of 500 mg i.v., 1000 mg i.v., 500 mg p.o and 1000 mg p.o. q 6 h, respectively, whereas a maximal inhibition of IL6 of 29%, 44%, 13% and 22% are predicted for the respective regimens. The inhibitory effect of erythromycin on TNF-alpha and IL6 production can be adequately described by the indirect response model with an Emax concentration-effect relationship. Simulations predicted a substantial decrease of production of these cytokines at intravenous and to a much lesser extent at oral erythromycin dosage regimens.

Administration, Oral↗
PubMed2001

Erythromycin inhibits Pseudomonas aeruginosa-induced tumour necrosis factor-alpha production in human whole blood.

Erythromycin has been shown to be beneficial for panbronchiolitis, a disorder linked to infection with Pseudomonas aeruginosa. Erythromycin, but not the anti-Pseudomonas antibiotics imipenem, ceftazidime, gentamicin and ciprofloxacin, caused a dose-dependent decrease in the production of tumour necrosis factor (TNF)-alpha by whole blood stimulated with heat-killed P. aeruginosa. The release of interleukin (IL)-10, IL-6, interferon-gamma and IL-8 was inhibited only at the highest erythromycin concentration. Inhibition of TNF-alpha production by erythromycin may, at least in part, explain the efficacy of this macrolide during panbronchiolitis despite its lack of activity for P. aeruginosa.

Anti-Bacterial Agents↗