Preoperative Cardiac Diagnostics in Bariatric Patients with Diabetes and Perioperative Morbidity: Results of a Cohort of 258 Patients.

PURPOSE: The combination of obesity and diabetes mellitus are well-known risk factors for cardiovascular complications and perioperative morbidity in metabolic surgery. The aim of this study was to evaluate effectivity and reliability of the cardiac assessment in patients with diabetes prior to bariatric surgery. SETTING: Private, university-affiliated teaching hospital, Switzerland MATERIAL AND METHODS: Retrospective analysis of prospectively collected data on results and consequences of cardiac assessments in 258 patients with obesity and diabetes scheduled for primary bariatric surgery at our institution between January 2010 and December 2018. RESULTS: Out of 258 patients, 246 (95.3%) received cardiac diagnostics: 173 (67.1%) underwent stress-rest myocardial perfusion scintigraphy (MPS), 15 (5.8%) patients had other cardiac imaging including cardiac catheterization, 58 (22.5%) patients had echocardiography and/or stress electrocardiography, and 12 (4.7%) patients received no cardiac evaluation. Subsequently, cardiac catheterization was performed in 28 patients (10.9%), and coronary heart disease was detected and treated in 15 subjects (5.8%). Of these 15 individuals, 5 (33.3%) patients had diffuse vascular sclerosis, 8 (53.3%) patients underwent coronary angioplasty and stenting, and 2 (13.3%) patients coronary artery bypass surgery. Bariatric surgery was performed without perioperative cardiovascular events in all 258 patients. CONCLUSION: Our data suggest that a detailed cardiac assessment is mandatory in bariatric patients with diabetes to identify those with yet unknown cardiovascular disease before performing bariatric surgery. We recommend carrying out myocardial perfusion scintigraphy as a reliable diagnostic tool in this vulnerable population. If not viable, stress echocardiography should be performed as a minimum.

Drug interaction between rifampicin and sirolimus in transplant patients.

We report two cases of drug interaction between rifampicin and sirolimus in renal trans-plant patients who were diagnosed with tuberculosis after transplantation and induction of immuno-suppressive therapy with sirolimus. The dosage of sirolimus had to be increased, in one case up to six-fold and in the second case up to five-fold, to maintain serum levels after starting the rifampicin. The two patients tolerated the treatment well, with no signs of tuberculosis and good renal function.

Post pressure hyperemia in the rat.

In prior studies in man, we have demonstrated that pressure-induced hyperemia lasts for prolonged periods as compared to the short-term hyperemia created by proximal arterial occlusion. We have analyzed this phenomenon in our well-studied rat model of skin blood flow. Skin blood flow was measured using laser Doppler techniques in Wistar Kyoto rats at the back, a nutritively perfused site, and at the plantar surface of the paw, where arteriovenous anastomotic perfusion dominates. A customized pressure feedback control device was used to vary applied pressures. At the back, pressures in excess of 80 mmHg resulted in occlusion, whereas at the paw 150 mmHg was required. The peak hyperemic flow after release of pressure was comparable to that elicited by proximal arterial occlusion with a blood pressure cuff. However, the post pressure hyperemia peak descended to a plateau value, which was 50-100% greater than baseline and continued for up to 20 min while the peak following proximal arterial occlusion returned to baseline within 4 min. At the back, post pressure hyperemia reached a maximum after application of 100 mmHg pressure. The application of higher pressures than required for occlusion produced no greater hyperemic response. At the paw, maximum post pressure hyperemia occurred at 100 mmHg, although this pressure level was not totally occlusive. Higher pressures resulted in no greater hyperemia. At the back, 10 min of occlusion produced a maximal peak value whereas 1 min was sufficient at the paw. The application of pressure to a heated probe with subsequent release, produced a hyperemic response. Normalized to baseline blood flow, there was no difference between the hyperemic responses at basal skin temperature and at 44 degrees C. There is a prolonged hyperemic response following local pressure occlusion compared to a much shorter period following proximal ischemic occlusion. One can presume two different mechanisms, one related to ischemia and the other a separate pressure related phenomenon. The thermal vasodilatory response is additive, not synergistic with the post pressure hyperemia we have demonstrated. This finding suggests that different mechanisms are involved in thermal vasodilation and post pressure hyperemia.