European journal of cardio-thoracic surgery : official journal of the European Association for Cardio-thoracic Surgery
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Eur J Cardiothorac Surg · Jul 2006
The influence of positive end-expiratory pressure on stroke volume variation and central blood volume during open and closed chest conditions.
Intermittent positive pressure ventilation and positive end-expiratory pressure (PEEP) affect cardiac preload. Their effect is dependent on chest wall compliance. This study compares the effects of intermittent positive pressure ventilation and PEEP on stroke volume variation and central blood volume during open and closed chest conditions. ⋯ We conclude that PEEP increases right and left ventricular stroke volume variation both during open and closed chest conditions. The concomitant reduction of right ventricular end-diastolic volume further indicates that PEEP has a preload reductive effect during open chest conditions, too.
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Eur J Cardiothorac Surg · Jul 2006
Hyporesponsiveness of T cell subsets after cardiac surgery: a product of altered cell function or merely a result of absolute cell count changes in peripheral blood?
The activity of the specific immune system and especially the function of T helper (TH) cells are reduced after cardiac surgery. This decrease is followed by an increase in TH2 cell activity and a delayed recovery of TH1 cell function (TH1/TH2 shift). Neither the underlying cause nor the relationship between the absolute numbers of T lymphocyte subpopulations, the state of activation of these cells and cytokine synthesis in cell culture has been clarified. We conducted a prospective study in order to test the hypothesis that the decrease in specific immunity is not caused by dilution effects but by functional alterations in T cell subsets. ⋯ The number of immune cells of the specific and the non-specific immune system is not reduced in the immediate postoperative period. Haemodilution thus has no detectable effect on immune function at this time point. Beginning on d1, the function of specific immune cells, especially TH lymphocytes, is severely suppressed. This functional alteration appears not to be preceded by T cell activation during CPB. Although TH cell activity begins to increase on d1, cytokine synthesis is reduced. When cytokine synthesis is corrected to the absolute number of TH cells in culture, there is strong evidence for an increase in TH2 cell activity. On the whole, these results corroborate the hypothesis of a TH1/TH2 shift that is primarily caused by an alteration of TH1 function. Neither haemodilution nor a preceding activation plays a major role.
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Eur J Cardiothorac Surg · Jul 2006
Intraoperative mapping of the right atrial free wall during sinus rhythm: variety of activation patterns and incidence of postoperative atrial fibrillation.
The atrial conduction properties associated with cardiac disease are speculated as the background of postoperative atrial fibrillation (POAF). We examined the atrial conduction patterns and conduction properties during sinus rhythm (SR) in patients that had undergone cardiac operations and evaluated the incidence of POAF in all patients. ⋯ Cardiac surgery patients exhibited a variety of sinus activation patterns, which also provided an arrhythmogenic substrate for POAF. A better understanding of the sinus activation using an intraoperative mapping system may provide benefit in the clinical management of POAF.
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Eur J Cardiothorac Surg · Jul 2006
ReviewThe role of hyperbaric oxygen therapy in the treatment of sternal wound infection.
Sternal wound dehiscence and infection are major problems for patients and health care providers. A range of risk factors, including diabetes, obesity and internal thoracic artery harvest, has been implicated. Several pathophysiological mechanisms, which may account for the development of infection, have been proposed. ⋯ It has been suggested that there may be a role for hyperbaric oxygen therapy in the treatment of sternal infection. The theoretical mechanisms would seem plausible, but at present there is only limited evidence to support its use. This review addresses the theory and evidence supporting the role of hyperbaric oxygen therapy in the treatment of sternal wound infection.
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Eur J Cardiothorac Surg · Jul 2006
Patient-prosthesis mismatch does not affect survival following aortic valve replacement.
Patient-prosthesis mismatch (PPM) has been reported to increase perioperative mortality and reduce postoperative survival in patients undergoing aortic valve replacement (AVR). We analysed the effect of PPM at values predicting severe mismatch on survival following AVR in our unit. ⋯ Severe patient-prosthesis mismatch was predicted in 4-10% of patients undergoing AVR but this did not affect in-hospital mortality or mid-term survival.