Perfusion
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Over the last few years, near-infrared spectroscopy (NIRS) has been introduced to study cerebral haemodynamics and oxygenation. This paper points out how the use of an external source of CO2 effects on the absolute value of cerebral NIRS during cardiac surgery on cardiopulmonary bypass. ⋯ Nowadays, NIRS is usually used in cardiac surgery to reduce possible risks of neurological damage. The importance of the role of pCO2 in the cerebral vascular resistance and in cerebral blood flow has already been proven. This research demonstrates a relationship between pCO2 and the NIRS value. This paper could introduce an important correcting tool when an inadequate NIRS value occurs although the level of oxygenation, haematocrit and mean arterial pressure are acceptable and the arterial line is accurately positioned.
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Given that micelles of lipids are colloids, the hypothesis was generated that the rapid administration of large volumes of soybean oil micelles would be an effective perfusion fluid. We also hypothesized that oxygen loading would be enhanced due to the greater solubility of oxygen in lipids compared to water. ⋯ (1) Soybean oil emulsions were superior to other fluids in restoring and maintaining the blood pressure; (2) oxygen-carrying ability of soybean oil micelles exceeds that of water and follows Henry's law between 10% and 30% w/v oil content; (3) nitric oxide was carried by the micelles; (4) animals receiving soybean oil micelles did not exhibit fat embolization; (5) colloids comprised of soybean oil-containing micelles may be used to replace blood loss and may be used to deliver oxygen and other potentially therapeutic gases such as nitric oxide to tissues.