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C Diefenbach

Publications and source records attributed to C Diefenbach.

67 records · Page 4Linked to original sources
PubMed1992

Atracurium and vecuronium: repeated bolus injection versus infusion.

The purpose of this study was to compare the characteristics of recovery from neuromuscular blockade after either atracurium or vecuronium given by intravenous infusion or by repeated injection. Four groups of 10 patients each were studied during nitrous oxide narcotic anesthesia. An initial intravenous dose of 2 x ED95 of either muscle relaxant was followed by an intravenous infusion started at 5% recovery of control twitch tension and adjusted for 95% block or by repeated injection of 0.6 x ED95 administered whenever twitch tension had returned to 25% of control. There were no significant differences between the maintenance doses required based on method of administration: atracurium repeated injection, 1.6 +/- 0.3 x ED95 h-1; atracurium infusion, 1.7 +/- 0.3 x ED95 h-1; vecuronium repeated injection, 1.8 +/- 0.5 x ED95 h-1; and vecuronium infusion, 1.6 +/- 0.4 x ED95 h-1. Nevertheless, differences of up to 20 min were noted in the recovery indices in the following order: atracurium repeated injection = atracurium infusion less than vecuronium repeated injection less than vecuronium infusion. A single dose of neostigmine (7 micrograms/kg) significantly reduced the recovery indices, thereby eliminating their differences.

Adult↗
PubMed1992

Greater neuromuscular blocking potency of atracurium during hypothermic than during normothermic cardiopulmonary bypass.

Previous studies drew attention to the greater neuromuscular blocking potency of atracurium during, than before or after, hypothermic cardiopulmonary bypass (CPB) while disregarding the periods of normothermic perfusion. We recorded the evoked twitch tension in 15 patients during nitrous oxide/narcotic anesthesia who were undergoing open heart surgery. Atracurium was injected as an initial bolus dose of 460 micrograms/kg. Waning neuromuscular blockade was enhanced by repeat injections of 138 micrograms/kg whenever the twitch tension attained 25% of control. During hypothermic (< 32 degrees C) and normothermic (> 34 degrees C) CPB, the times of onset of the maintenance doses were 57% and 18% longer, respectively, than before CPB (P < 0.05). Maintenance doses of atracurium were required every 24 +/- 4 min (mean +/- SD) before CPB, every 45 +/- 8 min (P < 0.05) during hypothermia, every 22 +/- 3 min during normothermic perfusion, and every 23 +/- 3 min after CPB. In conclusion, the patients' changing demand of atracurium paralleled the changes of temperature rather than the institution and cessation of CPB.

Aged↗
PubMed1992

Surgical treatment of myocardial bridging causing coronary artery obstruction.

Nine patients with obstruction of coronary artery blood flow caused by myocardial bridging underwent surgery after failure of medical treatment. The diagnoses were made angiographically at rest or during beta-stimulation. Impaired blood flow was found only in the left anterior descending artery in seven patients and additionally in the diagonal branch in two. The operations, performed with cardiopulmonary bypass consisted of complete dissection of the overlying myocardium. All patients survived the operation. Major intraoperative complications were accidental opening of the right ventricle in two patients. Postoperative scintigraphic and angiographic studies demonstrated restoration of coronary flow and myocardial perfusion without residual myocardial bridges under beta-stimulation. Surgical relief of myocardial ischemia due to systolic compression of intramyocardial coronary arteries can be accomplished with low operative risk and with excellent functional results.

Adult↗
PubMed1989

Long-term results of thrombolytic therapy with and without percutaneous transluminal coronary angioplasty.

The effects of combined intravenous and intracoronary streptokinase without (Group I, n = 103) or with (Group II, n = 103) immediate coronary angioplasty were evaluated during a long-term (3 year) follow-up of 206 patients with acute transmural myocardial infarction. There were no baseline differences between the groups with regard to gender, age, infarct location, serum creatine kinase levels, time between onset of symptoms and treatment and coronary artery patency rate. Angioplasty was performed with a success rate of 69% and a reocclusion rate of 2%. Elective angioplasty was performed in 22 (21%) of 103 patients in Group I and 9 (9%) of 103 patients in Group II, with a success rate of 86% and 100%, respectively, reflecting the higher incidence of angina pectoris and antianginal therapy in Group I. Coronary bypass surgery was performed in 21 (20%) of 103 patients in Group I and 20 (19%) of 103 patients in Group II; there was one operative death in each group. During follow-up, coronary reocclusion or reinfarction, or both, occurred in 25 (29%) of 87 patients in Group I and in 16 (18%) of 87 patients in Group II with reperfused vessels (p = NS). Heart failure occurred in 40% of the patients in both groups who had increased end-diastolic and end-systolic volumes. The survival rate after 3 years was 78% in Group I and 80% in Group II (p = NS). Thus, long-term follow-up of patients with acute transmural infarction treated with and without immediate angioplasty does not demonstrate any difference with regard to clinical outcome and mortality.

Angioplasty, Balloon↗
PubMed1989

[Mechanomyography and electromyography--2 competing methods of relaxometry using vecuronium].

The recording of the evoked twitch tension has been the established reference method to quantitate neuromuscular blockade. The evoked compound electromyogram has been introduced later as a clinically more convenient alternative. We compared both methods in 20 patients in whom cumulative dose response curves of vecuronium and the time constants of weaning neuromuscular blockade were determined. The evoked twitch tension was slightly more sensitive in detecting residual neuromuscular blockade than the EMG. No significant differences between the two methods were found in the cumulative 90% blocking dose, the duration of block and the recovery time (25%-75%). These results are in agreement with communications of previous authors using different nondepolarizing muscle relaxants. In the absence of abnormal conditions such as neuromuscular disorders and hypothermia, recording of evoked electromyography is a clinically satisfactory method to quantitate neuromuscular blockade.

Adult↗
PubMed1988

Recombinant single-chain urokinase-type plasminogen activator during acute myocardial infarction.

Recombinant single-chain urokinase-type plasminogen activator was intravenously administered in 2 different doses in 24 patients with acute myocardial infarction and angiographically proved occlusion of the infarct-related artery. Patients with first infarction without contraindications of thrombolysis were treated within the first 4 hours after the onset of symptoms. Group A (12 patients) received 20 mg of rscu-PA as a bolus followed by 60 mg infused over 1 hour and group B received 10 mg as a bolus and 30 mg as infusion. The 2 groups showed no significant difference in age, sex, height, weight, time between onset of symptoms and start of therapy, peak values and course of infarct-related enzymes. Time to reperfusion was 43 minutes in group A versus 67 minutes in group B (p less than 0.005). The rate of reperfusion 90 minutes after start of treatment was 91% in group A and 50% in group B (p less than 0.001). Plasma levels of fibrinogen, plasminogen and alpha-2-antiplasmin did not differ significantly in both groups. Systemic lytic state (fibrinogen less than 100 mg/dl) occurred in 33% of group A and in 9% of group B. Intravenous infusion of 80 mg (but not 40 mg) of rscu-PA led to reperfusion of the occluded coronary artery in nearly all patients. Approximately one-third of the patients treated with this dose demonstrated systemic lysis.

Adult↗
PubMed1987

A dose-response study of intravenous enoximone in congestive heart failure.

Previous clinical studies with intravenous enoximone have used cumulative dosing to quantify enoximone's hemodynamic effects. The magnitude and duration of the hemodynamic effects of single intravenous doses of enoximone were evaluated in patients with congestive heart failure. Sixty patients, who were in New York Heart Association functional classes III and IV, received single intravenous doses of enoximone, either 0.25 (12 patients), 0.5 (13 patients), 1 (14 patients), 1.5 (10 patients) or 2 mg/kg (11 patients). Cardiac index was increased by 20% with the 0.25 mg/kg dose and by 48% and 42% with the 1.5 and 2 mg/kg doses, respectively. These increases were statistically significant (Student's paired t test with Bonferroni's correction, p less than 0.007) for 1 hour after 0.25 and 0.5 mg/kg, for 2 hours after 1 mg/kg and for 4 hours after 1.5 and 2 mg/kg. Enoximone also reduced pulmonary artery diastolic pressure by 19% with 0.25 mg/kg and by 29% with 2 mg/kg. The duration of effect varied from 1 hour with 0.25 mg/kg to 4 hours with 2 mg/kg. Enoximone produced no consistent or dose-related effects on heart rate or blood pressure. Eighteen adverse reactions were reported by 15 patients, of which 11 were minor and transient (vein pain, flushes, nausea). In 5 patients ventricular or supraventricular arrhythmias were observed, including nonsustained ventricular tachycardia and extrasystoles; 3 of these patients had evidence of arrhythmias before enoximone. Laboratory studies before and after treatment showed no drug-related effects. Dose-related effects on the magnitude and duration of hemodynamic responses to intravenous enoximone were evident within the dose range of 0.25 to 2 mg/kg.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

[Long-term therapy of chronic cardiac insufficiency using enoximone].

Effect and tolerance of the oral phosphodiesterase inhibitor Enoximone was tested in 14 patients with advanced cardiac failure (New York Heart Association groups II-IV). During a mean observation period of 40 weeks there were four deaths; one patient became therapy-resistant. The remainder reported sustained clinical improvement. During the observation period there were no changes in heart rate or arterial blood pressure. There were no significant changes in cardiothoracic ratio on the chest X-ray or of the echocardiographically determined left-ventricular diameters. However, there was a rise in shortening fraction from 13.5 +/- 6.4% to 16.8 +/- 6.5% after 26 weeks, and to 21.1 +/- 8.1 after 52 weeks (P less than 0.05). The ratio of the systolic time intervals, PEP/LVET, decreased correspondingly from 0.74 +/- 0.23 to 0.44 +/- 0.09 and 0.43 +/- 0.10 (P less than 0.05). Hemodynamic measurements after one-year treatment revealed an increase in cardiac index from 2.4 +/- 0.7 to 3.6 +/- 0.6 l/min X m2, and a fall in pulmonary artery wedge pressure from 25.5 +/- 9.7 to 12.6 +/- 13.0 mm Hg (P less than 0.001). The drug was well tolerated and there were no significant biochemical changes. Long-term ECG monitoring revealed no significant changes in the arrhythmia profiles. Enoximone thus proved to be a successful therapeutic agent in the management of advanced heart failure.

Adult↗
PubMed1986

Balloon coronary angioplasty in patients with acute myocardial infarction.

After successful thrombolysis, approximately 75% of all patients will have significant coronary stenosis, which can be dilated by means of percutaneous transluminal balloon angioplasty (PTCA). In a randomized control study, 95 of our patients (Group I) had thrombolysis alone, whereas 95 others (Group II) had thrombolysis and PTCA. Both groups were comparable with respect to age, sex, infarct location, and maximal creatine kinase (CK) value. The clinical outcome during the hospital phase was better in Group II, which had a reocclusion rate of 13%, a reinfarction rate of 5%, a lethal reinfarction rate of 2%, and a cardiac death rate of 7%, compared with respective rates of 20%, 13%, 7%, and 13% in Group I. Furthermore, in Group I, residual coronary stenosis immediately after thrombolysis (75% +/- 20%) did not improve significantly until the end of the hospital phase, when it decreased to 69% +/- 21%. In Group II, stenosis (78% +/- 16%) was improved by PTCA to 33% +/- 21%, and this improvement remained constant during the hospital phase (30% +/- 26%). In Group-II patients who had an unsuccessful PTCA, stenosis was approximately the same before dilatation (83% +/- 12%), after dilatation (80% +/- 17%), and at the control study (83% +/- 17%). The end-diastolic, end-systolic, and stroke volume indices, as well as the ejection fraction, also remained unchanged. In Group I, the number of pathologic wall segments (12.2 +/- 5.0) did not improve during the hospital phase (12.2 +/- 7.9), but in Group II, the improvement was significant (14.0 +/- 5.7 vs. 10.9 +/- 8.2) (p < 0.05). PTCA seems to improve the clinical outcome, reduce the infarction and mortality rates, and enhance myocardial perfusion and performance.

Journal Article↗
PubMed1986

[PTCA and intracoronary lysis in acute myocardial infarct].

In 76% of all patients in whom thrombolysis was successful a residual stenosis exceeding 75% luminal diameter was found. Some patients suffered from single, others from multi-vessel disease. In single vessel diseases immediate intracoronary balloon dilatation of the residual stenosis is feasible. In multi-vessel diseases an aortocoronary bypass operation may follow. In a non-randomized study of 411 patients treated successfully with thrombolysis the best prognosis during the hospital phase and the subsequent 12 months was found in those who had had bypass surgery; patients treated with PTCA had the next best prognosis, and those treated with medical therapy had the worst. In a randomized study 95 patients were treated with thrombolysis alone and another 95 patients with thrombolysis plus immediate PTCA. PTCA diminished the degree of stenosis significantly (78 +/- 16% vs. 33 +/- 21%; p less than 0.001). This value remained constant during the following four weeks (30 +/- 26%). The clinical course, segmental wall motion and myocardial perfusion were more favourable in the PTCA group. No differences were found regarding spontaneous and inducible ventricular electrical vulnerability. Immediate PTCA without prior thrombolysis was performed in 27 patients with overt cardiogenic shock. The clinical mortality was significantly lower than in comparative studies. Recanalisation was successful in 24 of 27 patients. PTCA is complementary to successful thrombolysis in acute myocardial infarction to improve the prognosis and myocardial perfusion.

Aged↗