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Biomedical subjects

N Bleese

Publications and source records attributed to N Bleese.

At least 37 records · Page 2Linked to original sources

Correlation of echocardiographic and surgical findings in acute bacterial endocarditis.

From January 1979 to April 1983, 72 patients (pts) with bacterial endocarditis were treated. During their first stay in hospital 36 of them (age range: 23-67 years) underwent cardiac surgery because of severe congestive heart failure, unsuccessful antibiotic treatment of the infection and/or embolic events. In all these cases cardiac surgery was performed without preoperative catheterization. Surgery was recommended on the basis of clinical as well as M-mode and 2D echocardiographic findings. In 32 of the 36 pts the echocardiographic study completely predicted the surgical findings (23x the aortic valve, 1x the mitral valve, 1x the tricuspid valve, 5x the mitral and aortic valve, 1x the aortic valve and a VSD and 1x the triscuspid valve and a VSD were involved). The preoperative echocardiographic diagnosis was incomplete in 4 of the 36 pts. One aortic aneurysm, one aortic root abscess and 2x vegetations on the mitral valve were not detected by echocardiography. Surgery was recommended in these 4 pts because of additional aortic valve endocarditis proven by echocardiography. We conclude that combined M-mode and 2D echocardiography allows the accurate prediction of morphological alterations of the heart in the setting of acute bacterial endocarditis. Thus cardiac surgery can be recommended in pts with acute bacterial endocarditis without preoperative heart catheterization and coronary angiography.

Acute Disease↗

[Value of echocardiography in the preoperative diagnosis of acute bacterial endocarditis].

Open-heart surgery was performed in 26 of 56 patients with acute bacterial endocarditis seen in three years. Non-controllable infection, cardiac failure or embolism were the indications for operation. In all instances pre-operative invasive angiographic diagnosis was dispensed with, indications being based entirely upon clinical findings plus the results of M-mode or cross-sectional echocardiography. In 22 of the 26 patients the pre-operative echocardiographic diagnosis coincided with the intra-operative one. In the other four patients the pre-operative echocardiographic findings were incomplete, but no surgically important information had been missed.

Adult↗

The reliability of echocardiography in preoperative diagnostics of bacterial endocarditis.

During a period of 4 years, 32 patients with acute bacterial endocarditis were admitted for cardiac surgical intervention. Uncontrollable infections, heart failure or embolism presented indications for the operation. In all cases, a preoperative, invasive angiography diagnostic was abandoned. The indication for surgical intervention was based on clinical criteria as well as the findings of one-dimensional or two-dimensional echocardiography. In 26 out of 32 patients who underwent surgical intervention, the preoperative echocardiography findings were in agreement with the intraoperative findings. In the remaining 6 patients, the preoperative echocardiographic findings were incomplete; in 2 cases particularly, it is important to note that an aneurysm of the ascending aorta had been missed. In view of these findings and results, we think that in acute bacterial endocarditis, the combined use of one- and two-dimensional echocardiography together with clinical findings can replace preoperative hemodynamic diagnostics.

Adult↗

[X-ray findings of the sternum after sternotomy (author's transl)].

X-ray examination of the sternum after sternotomy supplies proof of rupture of a suture, of dehiscence of the sternum, malpositioning of the wire ligature, of the cutting-through of the fixation wire by the bone, of the fracture, pseudoarthrosis and inflammation. Fractures can be located in the manubrium sterni, the body of the sternum, the xiphoid process and in one of the two parts of the sternum. Pseudoarthroses can be seen in the manubrium, in the body of the sternum or as longitudinal pseudoarthroses. Pseudoarthroses were found only in conjunction with inflammatory chances. Signs pointing to an osteomyelitis of the sternum can be very discreet. This applies to both the reactive scleroses and to osteolyses. In individual cases the examination of a fistula system allows identification of a connection to the bone or to the ligature material. Retrosternal abscesses can be differentiated in the computer tomogram from dissections after bolus injection. Diagnosis by exclusion requires tomography in two planes with complicated blurs. In such cases the diagnostic reliability is probably far superior to the reliability achieved by plain roentgenography and with longitudinal blurring.

Abscess↗

[Perioperative complete right bundle branch block after aorto-coronary bypass surgery (author's transl)].

In 322 patients undergoing isolated coronary artery bypass grafting, the possible factors responsible for the development of intraventricular conduction disturbances were investigated. In 18 patients (5.6%), complete right bundle branch was observed perioperatively, 2 of whom also demonstrated left anterior hemiblock. Left bundle branch block, either complete or incomplete, was not observed. Patients demonstrating perioperative complete right bundle branch block were further characterized by the finding that 14 of 18 (77.7%) had preoperative inferior wall infarction as opposed to only 34% in the remaining 304 patients. Fifteen of the 18 patients (83.3%) had prolonged aortic cross-clamp times in contrast to only 37.5% of the remaining patients. Three-vessel disease, present in 16 of the 18 (88.9%) patients, was less frequently present (56.2%) in those in whom complete right bundle branch block did not develop perioperatively. Application of the chi 2-test showed significant differences in all of the latter variables. The perioperative onset of complete right bundle branch block may be due to several factors. The results of this study indicate that the extent of scar tissue and arteriosclerotic changes as well as the ischemic time during surgery may play a decisive role. In ten of the patients, the perioperatively-incurred complete right bundle branch block was irreversible. Postoperative angiographic studies revealed no relationship between block development and graft occlusion.

Adult↗

Hemofiltration during extracorporeal circulation (ECC).

In cardiac surgery hemofiltration can be used: 1. to balance fluids during ECC, especially in long-term perfusion; 2. to carry out open heart procedures in patients with terminal renal insufficiency; 3. to treat acute hyperkalemia. The model of the 12.5 by 4.5 cm DIAFILTER TM and the model of operation are described. The compounds of the ultrafiltrate (UF) are identical with that of plasma water. Particles with a molecular weight of less than 50,000 can pass freely across the filtration membrane. The filtration capacity is 100 cc/min UF (Q blood: 300 cc/min, pressure across the membrane 600 mm Hg and hematokrit (Hkt) 25%). The technical details of operation are explained. Its general use as well as its simplicity is demonstrated in 10 patients.

Adult↗

Clinical application of cardioplegia in aortic cross-clamping periods longer than 150 minutes.

Out of more than 1000 patients operated upon by means of cardioplegia in profound myocardial hypothermia (15 degrees - 20 degrees C) aortic crossclamping time exceeded 150 min in 26 cases. The average clamping time in this group of patients was 169 +/- 22 min (150 to 227 min). The average duration of the cardioplegic coronary perfusion was 35 +/- 21 min (14 to 99 min). The following procedures were performed. Aneurysmectomy of the ascending thoracic aorta combined with valve replacement (n = 7); valve replacement combined with aorto-coronary bypass procedures (n = 9); multiple valve replacement (n = 3); multiple coronary grafting (n = 6) and one complicated reoperation. Three patients (11.5%) died, none intraoperatively and none as the result of a heart failure connected with the operation.

Adenosine Triphosphate↗

[Reversible myocardial ischaemia or irreversible myocardial fibrosis? Differentiation by biphasic 201thallium scintigraphy (author's transl)].

The results of biphasic 201thallium (201Tl) scanning were compared with those of coronary arteriography, left ventricular angiogarphy and stress ECG in 56 patients with coronary artery disease and six with no evidence of heart disease. There were 104 201Tl defects, 50 of them reversible. The defects were always located in the area supplied by a critically stenotic coronary artery. Correlation of regional wall motion with 201Tl activity demonstrated that in all forms of abnormal wall motion there was either ischaemia or fibrosis. The resting LV angiogram thus does not make it possible to distinguish between myocardial ischaemia and fibrosis. Taking the LV angiogram as a standard, the rate of false-positive 201Tl scintigrams was 5%, that of false-negative ones 23%. The biphasic 201Tl scintigram was more sensitive than the stress ECG in detecting myocardial ischaemia. It furthermore made it possible to localize the ischaemic (or fibrotic) region within the LV and to estimate its size.

Adult↗

[Is creatine kinase isoenzyme CK-MB a diagnostic tool for perioperative myocardial infarctions? (author's transl)].

There is still controversy of the validity of elevated CK-MB serum activity in the diagnosis of perioperative myocardial infarction after open heart surgery. CK-MB activity was investigated using myocardial and skeletal muscle biopsies and in sera postoperatively in 192 patients. In biopsies CK-MB fraction of total myocardial CPK was 37%, the total-CPK activity of human skeletal muscles still shows a 5% fraction of CK-MB. There has to be more than 8% CK-MB fraction of total CPK-serum-activity to take this as evidence of myocardial damage. 3 h postoperatively enzymatic-immunologic CK-MB test is no longer interfered by enzymes derived from hemolyzed erythrocytes. In patients without signs of myocardial lesions postoperatively mean CK-MB-activity is 11 to 27 U/1 depending on the operative procedure performed. Activity levels exceeding 50 U/1 are almost evident of myocardial infarction. Elevated CK-MB-serum activity is a sensitive parameter for myocardial lesions overestimating an event of infarction. It is a helpful tool diagnosing perioperative myocardial infarction.

Cardiac Surgical Procedures↗

[Prevention of edema during coronary perfusion with cardioplegic solution (author's transl)].

In arrested and with cardioplegic solutions perfused rabbit hearts the relation of perfusion-pressure and flow rate were examined, showing that edema of the myocardium can be avoided even using erythrocytes-free solutions by two measures. First the solution has to contain colloid active agents and secondly the perfusion pressure has to be significantly below the colloid-osmotic pressure. Furthermore the edema can be avoided by adding 300 mg 6-methyl prednisolone/1. If no attention is paid to these facts the coronary flow decreases constantly due to developing interstitial and interfibrillar edema and degenerative changes of endothelial cells of the capillaries, which even can undergo necrosis. These changes were not seen using steroids. On the contrary here we found by densitometry and increased number of lysosomes. These findings show the effectiveness of corticosteroids in stabilizing the cell membranes.

Animals↗

[Long-term cardiac arrest by cardioplegic coronary perfusion (author's transl)].

UNLABELLED: The Mg++ aspartate-procaine-cardioplegia has been proven in animal experiments as well as from 1970 til 1975 in more than 1000 open-heart-procedures by a myocardial temperature of 32 degrees C and aortic crossclamping time up to 40 minutes superior to all other known procedures of cardiac preservations. To guarantee a safe myocardial protection of the arrested heart for a remarkable longer period of total ischemia, we further developed the cardioplegic technique in the animal lab, and use it now clinically. PRINCIPLE: The arrest is induced by cardioplegia (Mg++ aspartate-procaine), than the arrested heart is cooled down to 15-20 degrees C by cardioplegic coronary perfusion maintaining the oxidative metabolism. The perfusion is stopped. The begin of ischemia is still under normal ATP-levels and continuous cardioplegia. TECHNIQUE: 1. Crossclamping of the aorta; 2. cardioplegic induced cardiac arrest by Mg++ aspartate-procaine (Kirsch); 3. Surface cooling of the heart; 4. Coronary perfusion by hypothermic cardioplegic solution (8-10 min, flow 80-120 ml/min, perfusion pressure maximal 30 mmHg). Perfusate: O2-saturated, erythrocyte free, 6% hydroxyethyl starch solution added 2 mM Mg++ aspartate, 4 mM procaine, 50 mM Na+, 5 mM K+, 0,5 mM Ca++, 25 mM HCO3-, 10 mM glucose, 200 mM mannitol, 250 mg/l 6-methylprednisolone. RESULTS: 84 patients (29 ACVB; 55 valve replacements); crossclamping time: 71 min (SD 22); total time of ischemia: 57 min (SD 18; max 96, min. 27 min); reperfusion time restoring normal excitation-contraction of the heart: 3 min (SD 2); weaning off bypass: 23 min (SD 14). Hemodynamic 12 h postop.: SO2 venous 76% (SD 6). No sympathicomimetics were used. Only 30% of myocardial ATP is splitted after 120 min of cardiac arrest. Electron microscopic findings show only small, reversible alterations of fine structure.

Adenosine Triphosphate↗

[Metabolism and ultrastructure of magnesium aspartate-procaine arrested hearts of rabbit and man (author's transl)].

In normothermia, mild, and deep hypothermia the metabolism and the electron microscopic structure were investigated in human and rabbit heart muscle after magnesium aspartate-procaine cardioplegia. In comparison to plain ischaemic arrest splitting of adenine nucleotides and glycogen was significantly reduced in all experiments with the induced cardioplegic arrest. For 40 min at 32 degrees C almost no changes in ultrastructure were seen in heart muscle after induced arrest, while severe and/or irreversible damages were seen in the cell structure of the heart muscle due to plain ischaemic arrest.

Adenine Nucleotides↗

[Diagnosis, frequency and importance of the "low-output-syndrome" in the postoperative period after mitral valve replacement (author's transl)].

From 1970 until 1975 single mitral valve replacement was carried out in 162 patients using Björk-Shiley disc prostheses. The surgical mortality (within 30 days postoperatively) was 9.3% (n=15). Out of these 15 patients 9 died due to myogenic cardiac insufficiency. 21 patients with "Low-output-Syndrome" due to myogenic insufficiency however survived. The improvement of intraoperative myocardial protection since 1972 (using hypothermia and cardioplegic induced cardiac arrest) reduced the frequency of myogenic cardiac insufficiency to 1%. Unrelated to the above mentioned we saw in 18.5% of all patients after ECC-procedures a temporary "Low-output-Syndrome" after the 3rd postoperative day due to pericardial effusion.

Cardiac Output↗

[Artificial respiration as treatment of postoperative complications after cardiovascular surgery: indication, technique, results (author's transl)].

From 1972 to 1974 524 patients underwent surgery with extra corporal circulation. 83 (15,8%) patients had to be postoperatively ventilated for a prolonged period or reintubed after a symptomfree interval due to anticipated or manifested complications. 31 (37%) out of these expired. There was no death due to the prolonged ventilation itself, shown by the group, in which the causes for the above treatment were others but respiratory failure or insufficiency. All patients of this group survived. Indications, technique and results are described and discussed.

Germany, West↗

[Treatment of postoperative renal insufficiency after cardiovascular surgical procedures by peritoneal dialysis (author's transl)].

In 1972 and 1973 there have been 698 (351 with ECC) cardiovascular surgical procedures. 29 cases of renal insufficiency were seen in this group, 15 requiring peritoneal dialysis. There were only two survivors in the latter group. However none died due to renal insufficiency. The indication, technique, complications, results are discussed in detail.

Acute Kidney Injury↗