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Biomedical subjects

J A Leusink

Publications and source records attributed to J A Leusink.

11 recordsLinked to original sources
PubMed1989

Pulmonary shunting after cardiopulmonary bypass.

The effect of cardiopulmonary bypass (CPB) on pulmonary function was investigated in 32 adult patients, including 23 patients undergoing coronary artery bypass grafting and nine patients undergoing heart-valve replacement. Clinical indicators for pulmonary insufficiency, such as chest X-ray, gas exchange and lung function tests were measured. Transthoracic electrical impedances were measured, and the mean specific thoracic impedance (RHO) was calculated. (RHO is an accurate indicator for the intrathoracic fluid content; low RHO values correspond with high intrathoracic fluid content.) Significant postoperative decreases in RHO were paralleled by a significant impairment of gas exchange. Chest X-rays demonstrated accumulation of intrathoracic fluid. Lung function tests showed significant postoperative decreases in lung volumes and vital capacity. These findings are consistent with the concept that CPB provokes an inflammatory reaction in the lung. The non-invasive RHO measurement proved to be simple and in good agreement with clinical indicators. This method may be a real asset in the prevention and treatment of pulmonary dysfunction after CPB. The possibility of calibrating RHO with respect to absolute values of intrathoracic fluid content should be investigated.

Cardiography, Impedance↗
PubMed1988

Renal function following open heart surgery: the influence of postoperative artificial ventilation.

In order to detect changes in renal perfusion and function in the postoperative period of open heart surgery, a prospective study of 21 patients following open heart surgery was performed. Cardiac output, renal blood flow, glomerular filtration and renal function parameters were determined during intermittent positive pressure ventilation (IPPV), and during spontaneous ventilation (SV). During IPPV, renal perfusion was found to be substantially decreased. The glomerular filtration rate was also reduced, but to a lesser extent, implying that the changes were due to a selective increase in postglomerular vascular resistance. The clearances of urea and creatinine were decreased during IPPV, but the clearances of osmoles and potassium were higher. The reabsorption of sodium, potassium and osmoles were also decreased during IPPV, but not that of urea. These findings are consistent with the development of increased renal venous pressure during IPPV, caused by impeded venous return to the heart. In the low cardiac output range a cardiac index in excess of 0.5l/min/m2 during IPPV seems necessary to achieve the same renal perfusion as during SV.

Acute Kidney Injury↗
PubMed1987

The effect of hemodynamic factors on cardiac performance following open heart surgery.

Sixteen patients who had undergone open heart surgery were studied in order to determine the factors influencing cardiac performance in the postoperative period. Hemodynamic influences during and following cardiopulmonary bypass were found to be more important than the preoperative cardiac function. The flow rate used during cardiopulmonary bypass had a pronounced influence on the post-operative cardiac performance. A low flow can result in the development of vasoconstriction postoperative with an increased chance of low cardiac output. A high flow during bypass is recommended, and in the postoperative period vasoconstriction must be treated vigorously to forecome low cardiac output.

Cardiac Output↗
PubMed1986

Hematological advantage of a membrane oxygenator over a bubble oxygenator in long perfusions.

To determine whether the large volumes of cardiotomy suction which occur during long perfusions can obscure the hematological advantage of the membrane oxygenator (MO) over the bubble oxygenator (BO), we studied 23 patients undergoing a coronary artery bypass grafting operation with an expected perfusion time of 3 hours (MO group, N = 10, SciMed spiral coil; BO group, N = 13, Shiley 100-A). During MO perfusion we found significantly higher platelet numbers, better platelet function (adenosine diphosphate-induced platelet aggregation), and less hemolysis (plasma hemoglobin), than during the BO perfusion. After the MO perfusion we measured significantly shorter bleeding times (Simplate II) and fewer transfusions of blood products. However, blood loss and whole-blood transfusions 18 hours after perfusion did not differ significantly between both groups. So in coronary artery bypass grafting operations with long perfusion times (mean, 3 hours), the MO still causes significantly less platelet and erythrocyte damage than the BO, despite the large volumes of cardiotomy suction known to occur during these operations.

Coronary Artery Bypass↗
PubMed1985

Controlled cardiotomy suction during clinical bubble oxygenator perfusions.

Cardiotomy suction causes platelet damage and hemolysis due to air aspiration along with blood suction (uncontrolled suction = US). However, prevention of air aspiration (controlled suction = CS) reduces platelet damage and hemolysis and improves postoperative hemostasis, as only attainable in membrane oxygenator (MO) perfusions. We therefore studied 3 groups of patients subjected to extracorporeal circulation: bubble oxygenator (BO) with CS (n = 10), BO with US (n = 8) and MO with US (n = 10). If CS was used during BO perfusions we found that only hemolysis was significantly reduced, if compared to BO perfusions with US. Despite the use of CS during BO perfusions, platelets were still significantly better preserved during MO perfusions in which US was used. This was indicated by a higher platelet number, higher ADP-induced platelet aggregation, and lower beta-thromboglobulin plasma concentration, during and immediately after MO perfusions. Blood loss and blood transfusions during the first 18 hours after perfusion were not significantly different between the 3 groups. We conclude that the platelet-preserving capacity of CS is completely lost by the platelet damaging effect of the BO. However, reduction in hemolysis is well maintained.

Adenosine Diphosphate↗
PubMed1985

Serious acute renal failure following open heart surgery.

The influence of 51 preoperative, peroperative and postoperative variables on the development of serious acute renal failure (ARF) following open heart surgery was studied. Although a large number of significant variables was found, a logit-model with only 2 explanatory variables showed an almost perfect fit. With this model the chances of serious ARF up to 90% were estimated. The results suggest that a critical circulation is the main cause of serious ARF. Furthermore, a reduced ability to cope with a critical circulation without renal failure plays an important role in the pathogenesis. There is a higher risk of serious ARF for patients older than 70, especially when circulatory support with dopamine is needed.

Acute Kidney Injury↗
PubMedDate not supplied

Haematological characteristics of a new membrane oxygenator: the Cobe CML.

The new Cobe CML membrane oxygenator is more compact than other membrane oxygenators and has a combined venous and cardiotomy suction reservoir. Its size makes it as easy to use as a bubble oxygenator. The studies reported here were designed to show whether the excellent haemocompatibility found with other types of membrane oxygenators had ben compromised by the changes introduced in the Cobe CML oxygenator. Platelet number and function (ADP induced aggregation) plasma betathromboglobulin concentration and plasma haemoglobulin concentration were studied in nine patients where the Cobe CML oxygenator had been used and these were compared with ten patients managed with a Shiley S-100 bubble oxygenator. We conclude that the constructional changes of the Cobe CML oxygenator do not affect the haemocompatibility of this type of membrane oxygenator and that it remains significantly better than the Shiley S-100 bubble oxygenator.

Coronary Artery Bypass↗