44 research outputs found
Pulmonary abnormalities after cardiac surgery are better explained by atelectasis than by increased permeability oedema
No full textBACKGROUND: Cardiac surgery can be complicated by pulmonary abnormalities, but it is unclear how various manifestations interrelate. METHODS: A prospective study in the intensive care unit was performed on 26 mechanically ventilated patients without cardiac failure within 3 h after elective cardiac surgery involving cardiopulmonary bypass. Oedema (extravascular lung water, EVLW) was measured by the thermal-dye technique and permeability by a dual radionuclide technique, yielding a pulmonary leak index (PLI). Radiographic, mechanical and gas exchange features were used to calculate the lung injury score (LIS), ranging between 0 and 4. Evidence for left lower lobe atelectasis was obtained from plain radiographs. The plasma colloid osmotic pressure (COP) was measured by an oncometer. RESULTS: The EVLW (normal, 10 ml/kg. There was no difference in EVLW and PLI in patients with LIS 1 (31% of patients). In patients with radiographic evidence for atelectasis (46%), the positive end-expiratory pressure and inspiratory O2 fraction to maintain oxygenation were higher than in those without. CONCLUSIONS: After cardiac surgery, mild pulmonary oedema is relatively common, even in the absence of high filling pressures, and is mainly attributable to a low COP, irrespective of increased permeability in about one-half of patients. It may prolong mechanical ventilation at EVLW > 10 ml/kg. However, pulmonary radiographic and ventilatory abnormalities may result, at least in part, from atelectasis rather than increased permeability oedema
EFFECTS OF OPIATE RECEPTOR BLOCKADE ON GONADOTROPHIN SECRETION BEFORE AND AFTER ADMINISTRATION OF THE OESTROGEN RECEPTOR BLOCKER TAMOXIFEN IN EUGONADAL MEN
No full textBoth gonadal steroids and endogenous opioid peptides (EOPs) exert an inhibitory effect on gonadotrophin secretion. It is thought that the negative feedback action of the gonadal steroids, testosterone (T) and oestradiol (E2), on the gonadotrophin secretion is mediated by EOPs. To assess the effects of EOPs and oestrogen and their interrelationship on pulsatile LH secretion we studied two groups of eugonadal men. The subjects of the first group were tested on three different occasions, firstly under basal conditions, secondly during infusion of the opiate receptor blocker naloxone (NAL) (bolus 5 mg + 2.1 mg/h for 7 h), and finally during NAL infusion after 6 weeks administration of the oestrogen receptor blocker tamoxifen (10 mg twice daily). The subjects of the second group were studied before and after 6 weeks administration of tamoxifen. NAL infusion produced a significant increase in mean serum LH levels (4.8 ± SD 1.5 to 6.2 ± 1.8 U/l) and LH pulse frequency (3.7 ± 1.6 to 5.3 ± 1.2 pulses/7 h). No change was seen in mean LH pulse amplitudes (3.5 ± 1.5 vs 3.4 ± 1.0 U/l). After tamoxifen administration alone there was a significant increase in mean LH level (from 5.7 ± 1.3 to 10.1 ± 2.4 U/l), LH pulse amplitude (from 3.8 ± 0.9 to 4.6 ± 0.9 U/l) and LH pulse frequency (from 4.2 ± 1.5 to 5.8 ± 1.7 pulses/7 h). A significant rise in mean serum LH levels was observed during NAL infusion after previous tamoxifen administration in comparison to the infusion of NAL alone (from 6.2 ± 1.8 to 10.5 ± 6.2 U/l). LH pulse frequency (5.3 ± 1.2 vs 6.3 ± 1.3 pulses/7h) and amplitude (3.4 ± 1.0 vs 3.6 ± 1.5 U/l) however, did not change. Mean serum LH level and LH pulse frequency after opiate receptor and oestrogen receptor blockade together did not differ from the results obtained after oestrogen receptor blockade alone. NAL however was expected not only to block opioid‐mediated oestrogen action blockade on LH pulse frequency and mean serum LH levels after oestrogen receptor blockade could mean that the opioid inhibition depends on oestrogen rather than androgen action. If so there could be a parallel between the lack of effect of NAL infusion on gonadotrophin secretion in tamoxifen‐treated men and the same lack of effect in gonadectomized (Shoupe et al., 1985) and postmenopausal women (Reid et al., 1983; Melis et al., 1984; Caspar et al., 1985), in that a long‐term oestrogen deprivation reduces the opioid tone. The assumption that opioid inhibition is primarily dependent on oestrogen action conflicts, however, with a number of earlier studies on the relationship of androgens and EOPs. The feedback effect of the non‐aromatizable androgen dihydrotes‐tosterone can be blocked by NAL (Veldhuis et al, 1984) and androgen receptor blockade abolishes the LH response to NAL (Balzano et al., 1987). Another possible explanation is that androgen action was impeded after tamoxifen administration and for this reason blockade of androgen mediated opioid action by NAL infusion had no additional effect on the LH pulse frequency. In an earlier study we have found that antioestrogens probably interfere with androgen action on gonadotrophin secretion (Spijkstra et al., 1988). Such an effect was apparent in the group treated with tamoxifen alone in this study. While T levels had risen 60–80% following tamoxifen administration, this substantial rise was without a suppressing effect on LH pulse frequency, which had increased upon tamoxifen administration. The results obtained in this study therefore seem to be consistent with this assumption. However some caution is warranted when interpreting the results of the study in this way. Antioestrogens are known to bind to receptors other than E2 receptors (Sutherland et al., 1980), which raises the question if antioestrogens may exert effects other than their antioestrogenic or oestrogenic properties. Indeed studies with the antioestrogen clomiphene citrate both in vivo (Kerin et al., 1985) and in vitro (Miyake et al., 1983) provided indications in support of this assumption
Solar Powered Drones: PV Generator
No full textDrones are unmanned flying vehicles, which can be used for a broad spectrum of different applications. One of these applications is the generation of albedo maps. However, it could take some time to map an area. Therefore problems can occur the with respect to its flight range, which typically lies between 20 to 45 km for mini UAVs. The goal of this project is to design a PV powered drone that can create an albedo map of an area that is equal or bigger than the area of the Technical University of Delft. This is done by choosing and modelling an UAV system, where after choosing and modelling a PV generator system. Based on these models, power dynamics and flight ranges are calculated. The usability is tested for different weather conditions of Delft. The UAV system with PV generator without protection layers has a flying range between 129 and 250 km, depending in the irradiance. For the same system with protective layers, the flight range varies from 117 to 208 km. the total flight range that is needed to map the area of the TU Delft is 48.75 km. Therefore, there can be concluded that in both cases our goal has been achieved. When these results are compared to the weather conditions of the TU Delft, it can be concluded that on average a UAV system with PV generator will increase the flight range. However, when comparing this system to a system with additional batteries, the latter will achieve better results. In order to make sure that the PV generator system will guarantee a longer flight range, limitations regarding times, periods and places are made. Keep in mind that since these results are solely based on models of systems, it's best to create and test the physical system to validate the found results. This thesis is written in context of the Bachelor Graduation Project. We would like to express our gratitude to our daily supervisor Patrizio Manganiello and our supervisors Andres Calcabrini and Mirco Muttillo for their guidance during the project. Finally we would like to thank our colleagues: Laura Muntenaar and Sjoerd de Groot of the control algorithm project and Jetse Spijkstra and Martin Geertjes of the power electronics project for an enjoyable and productive collaboration. J. Koning & R. van der Hoorn Delft, June 2020</p
Short-term patterns of pulsatile luteinizing hormone secretion do not differ between male-to-female transsexuals and heterosexual men
No full textThis study tested whether there is a difference in the pulsatile LH secretion between male-to-female transsexuals and eugonadal heterosexual men. The mean serum LH concentrations, the LH pulse frequency, and the LH pulse amplitude were compared between a group of eight male-to-female transsexuals and a group of 22 heterosexual men. Blood samples for LH determinations were collected every 10 min for seven hours. 17-β-estradiol and testosterone were measured at the beginning of each test. There were no significant differences between the heterosexual and transsexual group in LH pulse frequency (3.9±1.3 vs. 3.9±1.7), LH pulse amplitude (3.7±1.3 U/l vs. 3.0±0.5 U/l), mean serum LH concentration (5.2±1.4 U/l vs. 5.4±1.1 U/l), 17-β-estradiol (0.07±0.01 nmol/l vs. 0.08±0.02 nmol/l), or testosterone (22.9±3.7 nmol/l vs. 21.8±8.0 nmol/l). We conclude that the pulsatile release characteristics of LH do not allow a distinction between eugonadal heterosexual men and eugonadal male-to-female transsexuals
Intra-observer variability in APACHE II scoring
No full textAlthough the APACHE II score is the most widely used scoring system in intensive care units worldwide, its reliability and variability have not been extensively studied. Differences in case-mix may complicate comparison and interpretation of results. We hypothesised that a degree of variability might be inherent to use of the APACHE II scoring system, and decided to assess intra-observer variability in APACHE II scoring as a potential indicator of inherent score variability. APACHE II scores were assessed twice from the charts of 11 patients by 14 physicians, with a time interval of 4 (range 3.5-4.5) months between the two assessments. Intra-observer was found to be approximately 15%. These findings are in agreement with previous observations regarding inter-observer variability in APACHE II scoring, and strongly suggest that there is an inherent score variability of about 15%
Divergent effects of the antiestrogen tamoxifen and of estrogens on luteinzing hormone (lh) pulse frequency, but not on basal lh levels and lh pulse amplitude in men
No full textWe studied the role of estrogens on LH pulse modulation in men in two ways. Firstly, we compared LH pulse frequency and amplitude in 13 normal men before and after 6 weeks administration of the antiestrogen tamoxifen (10 mg twice daily). Secondly, we compared LH pulse frequency and amplitude between a group of 10 agonadal men not receiving sex steroid treatment and a group of 9 agonadal men (male to female transsexuals) continuously treated with 50 ng ethinyl estradiol/day. Tamoxifen administration to normal men resulted in a significant rise in the mean serum LH level from 5.7 ± 1.3 (± SD) to 10.1 ± 2.4 U/L, which was associated with significant increases in LH pulse frequency (from 4.2 ± 1.5 to 5.8 ± 1.7/7 h) and LH pulse amplitude (from 3.8 ± 0.9 to 4.6 ± 0.7 U/L). In the group of agonadal men the mean LH pulse frequency was 6.8 ± 1.5/7 h, while it was 5.9 ± 1.7/7 h in the estrogen-treated agonadal group (P = NS). The mean serum LH level and LH pulse amplitude were, however, significantly lower in the estrogen-treated agonadal men than in the agonadal men (14.7 ± 7.0 vs. 34.3 ± 8.6 and 4.1 ± 1.8 vs. 7.4 ± 1.8 U/L, respectively). We conclude that estrogens reduce basal LH levels and LH pulse amplitude. With regard to the modulation of LH pulse frequency our data provide contradictory results. While an antiestrogen increased LH pulse frequency in normal men, estrogen alone produced no change in LH pulse frequency in agonadal men. The study design in the agonadal men ignores the possible interaction of the two major testicular hormones (estradiol and testosterone) on gonadotropin secretion. Therefore, a possible explanation for this discrepancy in the effects of antiestrogen and estrogen could be an interaction between estrogens and androgens on gonadotropin secretion at the level of the LHRH pulse generator
Immunoparalysis as a cause for invasive aspergillosis?
No full textAspergillus infections are among the most feared opportunistic infections in humans. These organisms are ubiquitous in nature; protection against infection is usually provided by anatomical barriers and by the immune system. Tissue invasion by Aspergillus is uncommon, occurring primarily in the setting of immunosuppression. The prognosis of invasive aspergillosis is very poor. Although it is widely recognised that critically ill patients in the Intensive Care Unit (ICU) are at risk for nosocomial infections, it is not generally appreciated that such patients may also be at risk for opportunistic infections usually seen only in immunocompromised patients. This might be explained by a biphasic immunological pattern during sepsis: an early hyperinflammatory phase followed by an anti-inflammatory response, leading to a hypo-inflammatory state, the so-called compensatory anti-inflammatory response syndrome (CARS or immunoparalysis). We describe four patients admitted to our ICU for various reasons, without a history of abnormal immune function, who developed invasive pulmonary aspergillosis. We hypothesise that the occurrence of these opportunistic infections in our patients may have been due to immunoparalysis, and that perhaps all ICU patients with sepsis and multiple organ dysfunction syndrome (MODS) may be at risk for opportunistic infections such as aspergillosis as a result of this syndrome. Physicians treating critically ill patients in the ICU should be aware of the CARS/immunoparalysis syndrome and its potential to cause opportunistic infections, even in patients with normal immune function prior to ICU admission
The impact of COVID-19 on nursing workload and planning of nursing staff on the Intensive Care: A prospective descriptive multicenter study
No full textIntroduction: The impact of the care for COVID-19 patients on nursing workload and planning nursing staff on the Intensive Care Unit has been huge. Nurses were confronted with a high workload and an increase in the number of patients per nurse they had to take care of. Objective: The primary aim of this study is to describe differences in the planning of nursing staff on the Intensive Care in the COVID period versus a recent non-COVID period. The secondary aim was to describe differences in nursing workload in COVID-19 patients, pneumonia patients and other patients on the Intensive Care. We finally wanted to assess the cause of possible differences in Nursing Activities Scores between the different groups. Methods: We analyzed data on nursing staff and nursing workload as measured by the Nursing Activities Score of 3,994 patients and 36,827 different shifts in 6 different hospitals in the Netherlands. We compared data from the COVID-19 period, March 1st 2020 till July 1st 2020, with data in a non-COVID period, March 1st 2019 till July 1st 2019. We analyzed the Nursing Activities Score per patient, the number of patients per nurse and the Nursing Activities Score per nurse in the different cohorts and time periods. Differences were tested by a Chi-square, non-parametric Wilcoxon or Student's t-test dependent on the distribution of the data. Results: Our results showed both a significant higher number of patients per nurse (1.1 versus 1.0, p<0.001) and a significant higher Nursing Activities Score per Intensive Care nurse (76.5 versus 50.0, p<0.001) in the COVID-19 period compared to the non-COVID period. The Nursing Activities Score was significantly higher in COVID-19 patients compared to both the pneumonia patients (55.2 versus 50.0, p<0.001) and the non-COVID patients (55.2 versus 42.6, p<0.001), mainly due to more intense hygienic procedures, mobilization and positioning, support and care for relatives and respiratory care. Conclusion: With this study we showed the impact of COVID-19 patients on the planning of nursing care on the Intensive Care. The COVID-19 patients caused a high nursing workload, both in number of patients per nurse and in Nursing Activities Score per nurse
Twee patiënten met lactaatacidose en hypoglykemie als uiting van een lymfoom
No full textA 32-year-old man who had undergone kidney transplantation presented with malaise, severe diarrhoea, nausea and vomiting, productive cough and shortness of breath. A 42-year-old woman with no relevant medical history presented with fever, weight loss and abdominal pain. Both patients had lactic acidosis and hypoglycaemia. Initially, the hyperlactataemia was thought to result from tissue hypoxia (sepsis) but it persisted after correction of the hypovolaemia; therefore, alternative causes were considered. Both patients were found to have T-cell lymphoma with liver infiltration. The male patient died before treatment could be initiated. The lactic acidosis resolved in the female patient following lymphoma treatment, but she died subsequently from the lymphoma. Lymphoreticular malignancies should be considered for cases of lactic acidosis with sufficient oxygen supply, particularly when hypoglycaemia is also present. The lactic acidosis and hypoglycaemia result from increased anaerobic glycolysis in tumour cells. Tumour reduction with chemotherapy can reduce the lactic acidosi
