Cytoprotective effect of isotonic mannitol at low oxygen tension

Current Technological Advances of Bipolar Coagulation

Background:

Heat has been used to control bleeding for thousands of years. In the 1920s, this concept was applied to the development of electrosurgical instruments and was used to control hemorrhage during surgical procedures. In the time that has passed since its first use, electrosurgery has evolved into modernday bipolar technology, involving a diverse group of coagulation instruments.

Methods:

We review the evolution and advances in electrosurgery, specifically bipolar coagulation, and the current technologies available for intraoperative hemorrhage control.

Results:

Electrosurgery has evolved to include highly accurate devices that deliver thermal energy via nonstick and noncontact methods. Over time, the operative range of coagulation instruments has increased dramatically with the incorporation of irrigating pathways, a wide range of instrument tips to perform various functions, and the application of bipolar technology to microforceps and microscissors for minimally invasive procedures.

Conclusion:

Electrosurgical devices and techniques, especially bipolar coagulation, have developed significantly with the availability of new technologies. This has led to better intraoperative coagulation control while minimizing iatrogenic damage associated with heat spread and tissue adherence, thus potentially improving outcomes for neurosurgical procedures.

The effects of mannitol, albumin, and cardioplegia enhancers on 24-h rat heart preservation

During 24 h in vitro heart preservation and reperfusion, tissue damage occurs that seriously reduces cardiac function. Prevention of free radical production during preservation and reperfusion of ischemic tissue using free radical scavengers is of primary importance in maintaining optimal heart function in long-term preservation protocols. We examined whether mannitol (68 mM) and albumin (1.4 microM) in combination with other cardioplegia enhancers decreased free radical formation and edema and increased cardiac function during 24-h cold (5 degrees C) heart preservation and warm (37 degrees C) reperfusion in the Langendorff-isolated rat heart. The performance of mannitol-treated hearts was significantly decreased compared with that of hearts without mannitol treatment after 24 h of preservation with regard to recovery of diastolic pressure, contractility (+dP/dt), relaxation (-dP/dt), myocardial creatine kinase release, coronary flow, and lipid peroxidation. Albumin-treated hearts demonstrated higher cardiac function (contractility and coronary flow especially) than hearts not treated with albumin or hearts treated with mannitol, and this appears to be due to the positive effects of increased cellular metabolism and the enhancement of membrane stability.

Isotonic mannitol and the prevention of local heat generation and tissue adherence to bipolar diathermy forceps tips during electrical coagulation. Technical note

The authors observed temperature levels of saline and mannitol on the tips of bipolar diathermy forceps during application of power to the forceps and compared the effects of irrigation with saline and isotonic mannitol on electrical coagulation of vessels during neurosurgical operations. There was a marked rise in the temperature of saline corresponding to increased output power of the coagulator; there was no rise in the temperature of the mannitol. Irrigation with isotonic mannitol during surgery resulted in a considerable reduction of adherence of burned tissue and blood clots to forceps tips during coagulation of both arteries and veins compared with that which occurred during irrigation with saline. These results demonstrate that irrigation with an isotonic mannitol surpasses that with conventional ionic fluids, such as a saline, for prevention of both tissue adherence to bipolar diathermy forceps and removal of heat generated during electrical coagulation.