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Biomedical subjects

H Metzler

Publications and source records attributed to H Metzler.

At least 73 records · Page 4Linked to original sources
PubMed1989

[10 years' experience with heart surgery in Jehovah's witnesses].

UNLABELLED: As a result of their interpretation of the Bible, members of Jehovah's Witnesses do not accept blood transfusions under any circumstances. Consequently, they present moral and ethical problems to surgeons and anesthetists, especially in cardiac surgery. PATIENTS and METHODS. From November 1978 to November 1988, 66 members Jehovah's Witnesses were scheduled for cardiac surgery; 57 patients were operated upon (mean age 33.3 years, 14 days to 70.4 years; mean body weight 51 kg, 0.7 to 95.5 kg); 21 were younger than 14 years. Patients with hematocrit (Hct) less than 35%, expected high intra- and postoperative blood loss, compromised left ventricular function, ST-segment alterations, critical aortic stenosis, severe unstable angina pectoris, complex heart defects, especially in children, extreme body weight, severe diabetes, renal insufficiency, coagulopathies, severe pulmonary disease, and heavy smokers were excluded from operation. Whereas in nonbypass patients no special blood-saving techniques were used, in bypass patients a modified version of isovolemic hemodilution, with a hypothermic, bloodless priming technique of extracorporeal circulation (ECC) was performed after induction of anesthesia. At the end of the ECC all blood collected in the pericardial and pleural cavities was returned to the oxygenator and the entire content of the extracorporeal circuit was infused into the patient through the aortic cannula. All patients receiving ECC were ventilated for 24 h postoperatively and received dopamine (2-5 micrograms/kg) and antibiotics routinely. RESULTS: Due to the above mentioned contraindications, 9 patients were not accepted for surgery, 10 were operated upon without cardiopulmonary bypass or blood-saving techniques. In 47 patients open heart surgery with ECC and moderate or deep hypothermia was performed. In the adult patients (n = 36) Hct values decreased from 44.4% (35-70%) preoperatively to 32.1% (21-46%) after hemodilution, reached their lowest levels during cardiopulmonary bypass at 17.9% (9.9-43%), and increased to 33.7% (22%-43%) at the end of the operation. Hct averaged 28.2% (20%-39%) on the 3rd and 33.2% (23%-46%) on the 12th postoperative day. In children (n = 11) Hct decreased from 47.2% (36.9%-70%) to 33.6% (27.2%-49.1%) after hemodilution, during bypass to 16.1% (10.5%-25.5%) and increased to 32.1% (24.4%-37.4%) at the end of the operation. On the 3rd postoperative day Hct was 25% (21.4%-39%) and increased to 29.4% (25.1%-40%) on the 12th postoperative day. No statistical differences in Hct values were found between both groups. (ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1988

Intraoperative heart rate reduction--alinidine versus metoprolol.

In a double-blind randomized protocol the effectiveness of the specific bradycardic agent alinidine (0.6 mg.kg-1 i.v.) was compared to that of the betablocker metoprolol (0.035 mg.kg-1 i.v.). Twenty-four coronary artery disease patients undergoing a bypass procedure with an intraoperative heart rate increase of more than 20% were included. Patients with a concomitant intraoperative mean arterial pressure increase of more than 30% or with an intraoperative wedge pressure higher than 15 mmHg (2.0 kPa) were excluded. After application of alinidine and metoprolol, heart rate decreased significantly (P less than 0.01) in the alinidine group from 88 +/- 19 beats per min to 72 +/- 13 and in the metoprolol group from 82 +/- 16 to 72 +/- 12. Baseline values were not obtained. Compared to the hemodynamic changes in the metoprolol group, the alterations of pulmonary capillary wedge pressure (PCWP) (P less than 0.05), stroke volume index (SVI) (P less than 0.05), left ventricular stroke work index (LVSWI) (P less than 0.01) and right ventricular stroke work index (RVSWI) (P less than 0.05) in the alinidine group were statistically significantly different. PCWP remained unchanged after alinidine and increased in the metoprolol group (1.4 +/- 0.4 to 1.6 +/- 0.4 kPa). In the alinidine group LVSWI (43.1 +/- 15 to 49.2 +/- 18 g-m.m-2), RVSWI (5.1 +/- 4 to 6.6 +/- 3 g-m.m-2) and SVI (37.2 +/- 12.2 to 42.5 +/- 12.8 ml.m-2) increased.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1986

[Antithrombin III behavior in open heart operations in infancy and early childhood].

Antithrombin III activity was evaluated preoperatively, intraoperatively and postoperatively in the plasma of 54 children with congenital heart disease undergoing open heart surgery. The patients were divided into an acyanotic and a cyanotic group. A comparison of these two groups indicated a significantly decreased AT III activity in cyanotic children as compared to acyanotic children throughout the perioperative phase. AT III levels decreased in the cyanotic group from 71.9 +/- 3.77% preoperatively to 61.5 +/- 2.15% (p less than 0.01) postoperatively and rose to 69.6 +/- 2.36% (p less than 0.01) on the first and to 78.9 +/- 2.24% (p less than 0.01) on the second postoperative day. In the acyanotic group AT III levels decreased from 84.3 +/- 1.98% to 73 +/- 2.97% (p less than 0.01) postoperatively and increased to 78.5 +/- 2.96% (p less than 0.01) on the first and to 90.2 +/- 3.06% on the second postoperative day. A few acyanotic patients, too, showed decreased values of AT III. However, they were never found to be as low as in the cyanotic group. Preoperative AT III values as well as the severity of underlying disease, the success of corrective surgical treatment and postoperative complications proved to be the predominant influencing factors of AT III activity.

Antithrombin III↗
PubMed1985

[Results of emergency aortocoronary bypass surgery in patients with acute myocardial ischemia after percutaneous transluminal coronary angioplasty].

From April 1980 to June 1985 7.3% (15) of 205 PTCA-treated patients required emergency operations. The spectrum of PTCA-induced ischemia included anginal pain alone (2/1, 13%) or transmural infarction (13/15, 87%) with hypotension (8/15), cardiac arrest (4/15), and severe cardiogenic shock (3/15, 20%). 14 patients underwent saphenous-vein-bypass-graft operation (ACBG) with a mean of 1.7 grafts performed per patient. The average time from onset of symptoms to completed revascularisation was 166.5 (110 to 290) minutes. Inspite of the use of IABP one hospital death (6.6%) occurred prior to the institution of ECC in a patient with previous ACBG surgery. No late death was observed during a mean follow up of 11.1 (1 to 33) months with 13/14 patients free of anginal symptoms. Retrospective assessment of postoperative serum enzyme levels of CPK and CK-MB showed evidence of myocardial infarctions in 7/14 (50%) patient. The incidence on ECG of Q-wave infarctions was 35,7% (5/14). With the exception of one patient, IABP was not used pre- or postoperatively. In patients with acute myocardial ischemia following PTCA-attempts immediate restoration of myocardial blood flow can stabilize left ventricular function and reduce the incidence and size of myocardial infarctions. The availability of emergency ACBG-surgery and facilities remain an important prerequisite of PTCA-programs due to the unpredictable natural course of PTCA-induced myocardial ischemia.

Adult↗
PubMed1985

[Open heart surgery in Jehovah's Witnesses].

Patients who are Jehovah's Witnesses present a special problem when undergoing open heart surgery since they refuse blood transfusion. We performed 15 open heart operations for both acquired and congenital heart disease using a modified version of isovolaemic haemodilution and bloodless prime technique of extracorporeal circulation. Two patients died. One death might have been at least indirectly related to the regimen which excludes blood substitution. We believe that our experience demonstrates the feasibility of open heart procedures in Jehovah's Witnesses, although the mortality risk is increased in these patients.

Adolescent↗
PubMed1985

[Hemodynamics in right heart damage under continuous positive pressure respiration. An experimental study of the open thorax].

The haemodynamic effects of isolated right ventricular damage (produced by pressure overloading from temporary banding of the pulmonary artery) under increased positive end-expiratory pressure were investigated in 12 pigs. Under controlled ventilation and anaesthesia with fentanyl and pancuronium bromide the experimental study was performed with an open chest and pericardium; under these circumstances high levels of PEEP resulted primarily in an increase of right ventricular afterload. RAP (+30,2%, p less than 0.05) and RVEDP (+196%, p less than 0,01) of the damaged right ventricle were increased markedly, dRVp/dt is decreased (-18%, p less than 0,05) with a corresponding endsystolic pressure-volume relationship. The decrease of CI after moderate right ventricular lesion is more distinct under PEEP (-27%, p less than 0,01) than previously (-13%). Because of an elevation of TPR-I (+24%) there was no significant fall of systemic arterial pressure (-6,6%); heart rate also remained constant (+3%). Accordingly, with the open chest, haemodynamic changes related to increased positive end-expiratory pressure are very discrete, both in intact and damaged right ventricles; only with high levels of PEEP, elevation of pulmonary vascular resistance--under open chest conditions the predominant factor--limits myocardial performance of the damaged right ventricle and results in a significant reduction of cardiac output.

Anesthesia↗
PubMed1984

[Myocardial changes in acute pulmonary artery embolism--an experimental study].

Massive pulmonary embolism usually causes acute right ventricular hypertension. Structural and hemodynamic effects of right ventricular overloading were studied in piglets (weight 17-22,5 kg). Pulmonary arterial obstruction (PAO) was achieved by temporary banding of the main pulmonary artery, the external diameter of the vessel being reduced to one-third (Group I) or by half (Group II) of the original size. In Group I PAO caused a twofold increase of systolic right ventricular pressure (RVP), whereas the systolic left ventricular pressure decreased to 30% of its original value; PAO was terminated after 25 seconds. After PAO, no changes of right or left ventricular function were observed in Group I. Electron microscopy revealed mitochondrial alterations and fragmentations of the sarcomeres. In Group II, PAO was maintained for 60 minutes. Due to PAO, the systolic RVP increased to twice the original value and the systolic aortic pressure decreased by 10%. During the PAO period, a continuous increase of enddiastolic RVP was observed in Group II. After termination of PAO, contractility parameters for the right ventricle were reduced, and right ventricular diameters (RVD) and enddiastolic RVP were increased in comparison to the pre-PAO values. As hemodynamic alterations increased corresponding to the duration of PAO, it is concluded that in case of acute pulmonary embolism early relief of right ventricular overloading may be important.

Acute Disease↗
PubMed1983

[Aortic valve replacement in cardioplegic heart arrest].

The St. Thomas cardioplegic solution was introduced in our clinic in January, 1980. Before, aortic valve replacements were carried out using cold ischaemic cardiac arrest as myocardial preservation technique. In 62 aortic valve replacements performed since January 1980, there was no hospital mortality. Moreover, there were fewer intraoperative and postoperative complications. Intraoperative serum potassium was not essentially elevated after cardioplegic perfusion of the heart, although most of the cardioplegic effluate passed into the extracorporeal circulation. Postoperative serum-creatinphosphokinase levels were significantly higher after cold ischaemic arrest than after cardioplegia.

Aortic Valve↗
PubMed1983

Treatment of postsurgical chylothorax with fibrin glue.

The treatment of postsurgical chylothorax with fibrin glue is reported. Chylothorax developed in a 3 1/2-month-old infant 2 days after extrapleural ligation of a patent ductus arteriosus. At rethoracotomy the chyle leak could not be located. To stop chyle effusion, the region of the presumed leakage was sealed with fibrin glue and a pleural flap. It is suggested that early reoperation and closure of the chyle leak with fibrin adhesive should be considered in cases of postsurgical chylothorax in infants.

Chylothorax↗
PubMed1982

Effect of tiapamil on perioperative cardiac arrhythmias and myocardial function.

Tiapamil was effectively used in 32 surgical patients in the treatment of intra- and postoperative cardiac arrhythmias such as atrial fibrillation, supraventricular paroxysmal tachycardia and extrasystoles and in ventricular ectopic beats. In 28 patients aged between 38 and 82 years, bolus doses of 0.3-1.5 mg/kg were used. Before administration, hypoxaemia, hypercarbia, metabolic acidosis and electrolyte imbalances were excluded. Small doses of 0.3-0.5 mg/kg were only effective in patients with tachycardic atrial fibrillation. In most other arrhythmias the effective dose was between 1 and 1.5 mg/kg. In 4 surgical patients aged between 56 and 82 years, the continuous infusion of 12-25 mg/h (in 2 patients preceded by a bolus injection of 1 mg/kg) was effective in abolishing arrhythmias. In 18 healthy subjects, systolic time intervals were measured continuously and noninvasively before, during and for 9 min after 1 mg/kg tiapamil or 0.13 mg/kg verapamil, given intravenously according to a randomization schedule. Heart rate increased and systolic blood pressure decreased slightly but significantly. A significant improvement in myocardial function, with a decrease in PEP and PEP LVET ratio, was found after both calcium antagonists. The effect of tiapamil on myocardial function lasted significantly longer than that of verapamil.

Adult↗
PubMed1982

[Role of the pericardium in acute volume overload].

The function of the pericardium in acute volume overloading may be defined as protection against ventriculo-atrial regurgitation at high filling pressures, limiting transmural pressures and, therefore, protecting against ventricular distension as well as supporting the filling of the ventricles by suction in the systolic contraction. Thus, it may be important to close the open pericardium carefully after open heart surgery. Pericardial drainage should prevent cardiac tamponade.

Animals↗
PubMed1981

Light-induced oscillations of the glutamate pool size and of the respiratory oxygen uptake in the blue-green alga Anacystis nidulans.

The glutamate and glutamine pool contains abut 75% of the free amino acids of Anacystis nidulans harvested from a growing culture. Light pulses induced oscillations of the rate of oxygen uptake and of the size of the glutamate pool under certain physiological conditions. The frequencies of these oscillations were similar. During the oscillation the size of the glutamate pool was transiently reduced to about 50% of the dark level. The pool size of 2-oxoglutarate did not show similar oscillations. A phase plane plot of the glutamate against the respiration oscillation supported a connection of both oscillatons.

Adenosine Triphosphate↗