A sea change in our view of overturning in the subpolar North Atlantic.

To provide an observational basis for the Intergovernmental Panel on Climate Change projections of a slowing Atlantic meridional overturning circulation (MOC) in the 21st century, the Overturning in the Subpolar North Atlantic Program (OSNAP) observing system was launched in the summer of 2014. The first 21-month record reveals a highly variable overturning circulation responsible for the majority of the heat and freshwater transport across the OSNAP line. In a departure from the prevailing view that changes in deep water formation in the Labrador Sea dominate MOC variability, these results suggest that the conversion of warm, salty, shallow Atlantic waters into colder, fresher, deep waters that move southward in the Irminger and Iceland basins is largely responsible for overturning and its variability in the subpolar basin.

Practice in the perioperative prevention of deep vein thrombosis in german neurosurgical departments: is there a trend towards homogenization?

OBJECTIVE: There was no consensus on the most suitable perioperative prophylaxis of deep vein thrombosis (DVT) in neurosurgical patients. The aim of this work was to review the current practice and search for a standard protocol in the prophylaxis of DVT. METHODS AND MATERIAL: Questionnaires addressing the routine prophylaxis of perioperative DVT for 4 groups of neurosurgical procedures and the estimation of risks and benefits of perioperative heparin (unfractionated and/or low-molecular-weight) administration were sent to 130 neurosurgical departments in Germany. RESULTS: 103 of 130 questionnaires were returned and suitable for analysis. The use of heparin (unfractionated and/or low-molecular-weight) is common, with some variation depending on the type of operation (83.5-99%). In spinal procedures, heparin administration is commonly started early, i. e., between the preoperative and first postoperative day (90.3-97.1%). This differs in intracranial procedures. In most neurosurgical departments heparin administration is stopped at the day of discharge (69.6-77.4% depending on procedure). Enoxaparin is the most commonly used heparin. In spinal as well as in cranial procedures, thrombosis risk reduction is unanimously assumed to be lesser the later administration starts. The estimation of the risks related to heparin injection are considered to be higher in cranial than in spinal operation in the early postoperative period. Most departments use antithrombotic stockings (ATS) irrespective of the type of surgery. However, 11% never use ATS. CONCLUSIONS: In spinal surgery, a trend towards homogenization is observed with the early use of heparin. In intracranial procedures, practice is more heterogenous. The heterogeneity is due to the fact that the data available in the literature does not allow for the identification of an optimal protocol.