Current European flood-rich period exceptional compared with past 500 years.

There are concerns that recent climate change is altering the frequency and magnitude of river floods in an unprecedented way1. Historical studies have identified flood-rich periods in the past half millennium in various regions of Europe2. However, because of the low temporal resolution of existing datasets and the relatively low number of series, it has remained unclear whether Europe is currently in a flood-rich period from a long-term perspective. Here we analyse how recent decades compare with the flood history of Europe, using a new database composed of more than 100 high-resolution (sub-annual) historical flood series based on documentary evidence covering all major regions of Europe. We show that the past three decades were among the most flood-rich periods in Europe in the past 500 years, and that this period differs from other flood-rich periods in terms of its extent, air temperatures and flood seasonality. We identified nine flood-rich periods and associated regions. Among the periods richest in floods are 1560-1580 (western and central Europe), 1760-1800 (most of Europe), 1840-1870 (western and southern Europe) and 1990-2016 (western and central Europe). In most parts of Europe, previous flood-rich periods occurred during cooler-than-usual phases, but the current flood-rich period has been much warmer. Flood seasonality is also more pronounced in the recent period. For example, during previous flood and interflood periods, 41 per cent and 42 per cent of central European floods occurred in summer, respectively, compared with 55 per cent of floods in the recent period. The exceptional nature of the present-day flood-rich period calls for process-based tools for flood-risk assessment that capture the physical mechanisms involved, and management strategies that can incorporate the recent changes in risk.

Influence of Elevated Intra-abdominal Pressure on Suture Tension Dynamics in a Porcine Model.

BACKGROUND: Inadequate suture tension is a risk factor for the failure of laparotomy closure. Suture tension dynamics in the abdominal wall are still obscure due to the lack of measuring devices. To answer the questions if intra-abdominal hypertension (IAH) influences suture tension in midline laparotomies and if IAH leads to a permanent loss of suture tension, microsensors were applied in a porcine model of IAH. MATERIAL AND METHODS: Microsensors measuring suture tension "on the thread" with a frequency of 1/s were developed and implanted in the suture lines of midline laparotomies in four pigs. During a 23-h experiment under general anesthesia, two intervals of IAH (30 mm Hg) were applied, interrupted by a 3-h interval without elevated intra-abdominal pressure. RESULTS: All sensors showed an immediate and reproducible response to changes of intra-abdominal pressure. The two 9-h periods of IAH resulted in a significant elevation of suture tension (P = 0.003 and P = 0.0009, respectively). Reducing the IAH lead to a significant loss of suture tension (P = 0.0005 and P = 0.0001, respectively). After the second interval with IAH, a complete loss of mean suture tension was observed. A statistically significant "recovery" of suture tension in the interval between the two phases with IAH was not observed. CONCLUSIONS: Intervals with elevated intra-abdominal pressure have a direct influence on suture tension in midline laparotomy wounds. Intervals with IAH lead to a significant loss of suture tension in the suture line and to a complete loss of mean suture tension at the end of this experiment. A subsequent gaping of the fascia might contribute to either acute or chronic failure of laparotomy closure.

Miniaturized Sensors Registering the Long-Term Course of Suture Tension In Vivo under Varying Intra-Abdominal Pressure.

BACKGROUND: Failure of laparotomy closure develops after up to 20% of abdominal operations. Suture tension has an influence on the quality of tissue regeneration. No sensors are available to register suture tension dynamics in vivo. METHODS: In a series of animal experiments, the effect of suture tension on the ultrastructure of the healing incision was examined. Surgeons' ability to suture with target tension was tested. An implantable sensor and data logger were developed and tested experimentally in sutures closing midline laparotomies in pigs both under normal and elevated intra-abdominal pressure. RESULTS: High suture tension has a negative influence on the regeneration of laparotomy incisions. Running sutures for laparotomy closure lose 45% of their initial tension over periods of 23 h. Intermittent elevation of intra-abdominal pressure to 30 mm Hg leads to a near total loss of suture tension after 23 h. CONCLUSION: Surgeons are not able to control and reproduce suture tension. Suture tension dynamics can be measured in vivo by the sensor developed. Further research is needed to define a tissue-specific suture tension optimum to reduce the incidence of complications after laparotomy. Techniques for laparotomy closure need to be modified.