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Biomedical subjects

Thomas R Karl

Publications and source records attributed to Thomas R Karl.

5 recordsLinked to original sources

Are we improving after 10 years of humanitarian paediatric cardiac assistance?

BACKGROUND: Paediatric cardiovascular services are frequently absent or poorly developed in many countries around the world. Our foundation made 83 trips in support of cardiovascular services between April 1993 and March 2003 to help alleviate this problem. In this study, we present an analysis of our results over these period of 10 years. METHODS: We performed a review of all available records relating to the trips, including patient databases, audited financial statements, donated product inventory lists, lists of team members, and follow-up data from the host sites concerning the state of the patients treated. RESULTS: We made 83 trips to 14 countries, 40 of these being in Central Europe, 5 in Eastern Europe, 10 in Caribbean, and Central America, 18 in South America, 9 in Asia, and 1 in the Middle East. In the first 5 years, we made 23, as opposed to 60 in the second 5 years, this difference being significant (p less than 0.01). The total number of primary operations performed over 10 years was 1,580. The number of procedures performed yearly increased over the two intervals from 97.0 plus or minus 32.7 to 219.0 plus or minus 41.7, p less than 0.002. The probability of survival between the periods increased from 84.6 to 93.3 per cent, and this was also significantly different (p less than 0.001). Overall, the rate of survival for the period of 10 years was 90.5 per cent. Moreover, the value of services donated to support each trip also differed significantly, decreasing from 105,900 dollars plus or minus 14,581 dollars for the first period to 54,617 dollars plus or minus 11,425 dollars for the second period (p less than 0.001). CONCLUSIONS: Improving paediatric cardiac services in under-served countries requires significant financial and personnel commitments, but can produce reasonable outcomes.

Altruism↗

Climate (communication arising): impact of land-use change on climate.

Urbanization and other changes in land use have an impact on surface-air temperatures. Kalnay and Cai report that the observed surface-temperature trend in part of the United States exceeds the trend in the NCEP/NCAR 50-year reanalysis (NNR) and conclude that changes in land use account for the difference (0.035 degrees C per decade according to their corrected values). Although land-use change may explain some of this discrepancy, the authors do not quantify the impact of the many changes in observational practice that occurred during the analysis period. Our findings indicate that these 'non-climatic' changes have a systematic effect that overwhelms the reported difference in trends and therefore calls Kalnay and Cai's central conclusion into question.

Comment↗

Modern global climate change.

Modern climate change is dominated by human influences, which are now large enough to exceed the bounds of natural variability. The main source of global climate change is human-induced changes in atmospheric composition. These perturbations primarily result from emissions associated with energy use, but on local and regional scales, urbanization and land use changes are also important. Although there has been progress in monitoring and understanding climate change, there remain many scientific, technical, and institutional impediments to precisely planning for, adapting to, and mitigating the effects of climate change. There is still considerable uncertainty about the rates of change that can be expected, but it is clear that these changes will be increasingly manifested in important and tangible ways, such as changes in extremes of temperature and precipitation, decreases in seasonal and perennial snow and ice extent, and sea level rise. Anthropogenic climate change is now likely to continue for many centuries. We are venturing into the unknown with climate, and its associated impacts could be quite disruptive.

Journal Article↗

Modified ultrafiltration postextracorporeal membrane oxygenation.

Modified ultrafiltration (MUF) has been widely used for the removal of extracellular water in the immediate postcardiopulmonary bypass (CPB) period. The reported benefits of this technique are improved hematological status and hemodynamic stability post-CPB, as well as a decrease in blood utilization during the operation. MUF has also been associated with improved pulmonary status along with enhanced myocardial performance. With these benefits in mind, we have explored the possible advantages of using MUF following extracorporeal membrane oxygenation (ECMO). The theoretical advantages of using MUF post-ECMO are the reduction of blood use prior to removal from ECMO for optimization of hemoglobin levels, improved pulmonary compliance decreasing the duration of ventilatory support, improved myocardial function, as well as the other reported benefits described with MUF post-CPB. This report communicates the technique used to perform MUF post-ECMO, as well as a simple MUF circuit design for use in the intensive care unit setting.

Cardiopulmonary Bypass↗