Artificial organs
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Small animal cardiopulmonary bypass (CPB) model would be a valuable tool for investigating pathophysiological and therapeutic strategies on bypass. However, the rat CPB models have a number of technical limitations. Effective maintenance and control of core temperature by heat exchanger (HE) is among them. ⋯ Arterial blood gases and hematocrits showed no further significant findings. We confirmed the effect of rectal temperature maintenance and hypothermic control using an HE of cardioplegia system in CPB model for rats. This model would be a valuable tool for further use in hypothermic CPB experiments in rats.
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For many years it has been assumed that patients undergoing cardiac surgery utilizing cardiopulmonary bypass accumulate an "oxygen debt" that requires a higher postoperative hemoglobin concentration for its reversal. Much of this evidence has now been discredited due to mathematical error with recent research suggesting critical levels of oxygen delivery are lower than previously thought. This article aims to explore the relationship between observed and critical oxygen delivery with an estimation of the minimal hemoglobin required. ⋯ Observed measurements of oxygen delivery were recorded and compared with calculated "critical" values adjusted for temperature. The hemoglobin value that represented critical oxygen delivery was compared with the observed value to identify any "hemoglobin reserve." At no perioperative time point did observed oxygen delivery or critical hemoglobin concentration significantly approach its corresponding critical value. Current transfusion practice in noncritically ill cardiac surgery patients may be considered excessive if systemic oxygen requirement is the sole parameter considered.
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There is increasing evidence showing that adult stem cells are useful for tissue regeneration. Bone marrow mesenchymal stem cells (MSCs) are self-renewing and are potent in differentiating into multiple cells and tissues. To investigate the practicability of repairing burn wounds with tissue-engineered (TE) skin combined with bone MSCs, we established a burn wound model in the porcine skin. ⋯ When grafted to the burn wounds, the TE skin containing MSCs showed better healing and keratinization, less wound contraction, and more vascularization. Grafts proliferated well and contributed to the neo-tissues. These data suggest that TE skin containing MSCs in a burn defect can accelerate wound healing and receive satisfactory effects.
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Particulate embolization remains a serious complication of cardiac surgery. Adverse events associated with particulate embolization affect patient morbidity and long-term survival, and increase the length of hospital stay and the cost of health care. Today, atherosclerosis plays a role in at least two-thirds of all adverse events after coronary artery revascularization, and postoperative stroke is the second most common cause of operative mortality. ⋯ Patients must be carefully assessed before surgery to determine their risk, and if the risk is high, surgeons should consider using newer, innovative devices, and techniques in their operative strategy that have proven to be effective in mitigating some of the potential embolic adverse events. A multifaceted, preventive strategy can make a difference, not only in reducing particulate emboli, but also in reducing morbidity and in lowering the economic burden on the health-care system. This brief review will address three areas of focus that are important for the prevention of particulate embolization: (i) prevalence and morbidity of atherosclerotic disease; (ii) risk factors for adverse neurologic events; and (iii) prevention/mitigation of adverse events for patients undergoing cardiac surgery.
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Randomized Controlled Trial
Nitric oxide in conjunction with milrinone better stabilized pulmonary hemodynamics after Fontan procedure.
Inhaled nitric oxide (iNO) has been used for patients with increased pulmonary vascular resistance (PVR) shortly after Fontan operation, but repeat deterioration of PVR during or shortly after its withdrawal remains a major concern. Milrinone, a phosphodiesterase type 3 (PDE3) inhibitor, can also reduce PVR for postoperative patients with pulmonary hypertension. We hypothesized that iNO, in conjunction with milrinone, can provide additive benefits for pulmonary hemodynamics and reduce the occurrence of iNO withdrawal failure/rebound. ⋯ Combined application of iNO and milrinone resulted in (i) more significant decrement of CVP (19.6 +/- 3.5% in group iNO + Mil vs. 15.2 +/- 4.6% in group iNO, P < 0.05) and TPG (18.2 +/- 4.8% in group iNO + Mil vs. 15.3 +/- 2.6% in group iNO, P < 0.05), (ii) more significant increment of systolic systemic arterial pressure (8.7 +/- 2.7% in group iNO + Mil vs. 5.2 +/- 3.1% in group iNO, P < 0.05), and (iii) more significant improvement of arterial oxygen saturation (9.3 +/- 3.2% in group iNO + Mil vs. 6.8 +/- 2.8% in group iNO, P < 0.01). Occurrence of iNO withdrawal failure during its weaning or rebound after its discontinuation was significantly lower in group iNO + Mil. The combined use of iNO and milrinone provided additive benefits as compared with exclusive use of iNO for patients with elevated PVR after Fontan procedure.