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Biomedical subjects

D Hausmann

Publications and source records attributed to D Hausmann.

At least 55 records · Page 3Linked to original sources
PubMed1992

Diagnosis of patent foramen ovale by transesophageal echocardiography and association with cerebral and peripheral embolic events.

This study compares the value of transthoracic (TTE) and transesophageal (TEE) color Doppler and contrast echocardiography for detecting a patent foramen ovale (PFO). A total of 238 patients were studied: 74 patients with a history of otherwise unexplained ischemic stroke, transient cerebral ischemic attacks or peripheral embolic events (group A), 48 with a history of similar episodes explained by other cardiac abnormalities (group B), and 116 with no embolic events (group C). A PFO was detected by contrast TEE in 50 of 238 patients (21%) compared with 45 patients (19%) by color Doppler TTE. In a subgroup of 198 patients, TEE results could be compared with TTE findings. No patient had a PFO identified by color Doppler TTE. Contrast TTE detected a PFO in 15 patients (8%) compared with contrast TEE which demonstrated a PFO in 44 of 198 patients (22%) (p less than 0.001). Prevalence of PFO by TEE was 22, 21 and 22% in groups A, B and C, respectively. A PFO was present in 50% of patients aged less than 40 years and otherwise unexplained ischemic stroke; this percentage was higher (p less than 0.05) than corresponding values found in all other groups. Thus, contrast and color Doppler TEE are significantly superior to TTE for detecting PFO. The prevalence of PFO is significantly increased in young adults with otherwise unexplained ischemic stroke.

Brain Ischemia↗
PubMed1992

[Muscle relaxation with no effect on oxygen uptake during isoflurane anesthesia?].

To determine the effects of vecuronium neuromuscular blockade on O2 consumption (VO2) during isoflurane anaesthesia 12 patients were studied. 12 patients (ASA-PS I-II, 37.1 +/- 12.1 yr, 173 +/- 8 cm, 70.1 +/- 8.6 kg), scheduled for urological lower abdominal surgery, received isoflurane-N2O-O2-anaesthesia under steady-state conditions (1.3 MAC). Duration of anaesthesia was 169 +/- 32 min and 0.057 +/- 0.016 mg/kg/h vecuronium were needed. The desired level of neuromuscular transmission was set to 10% of control. This level of neuromuscular blockade was kept constant for 60 min by a negative feedback controlled infusion of vecuronium. VO2 was measured by an indirect calorimetry device (MMC Horizon, STPD). During and after recovery of neuromuscular function anaesthesia was maintained and oxygen measurements were continued. Preanaesthetic values of VO2 were in the predicted range for basal metabolism. Steady-state general anaesthesia lead to an 26-28% reduction of VO2 (Range: 144-232 ml/min) compared to the preanaesthetic values (202-288 ml/min, p < 0.01). Neuromuscular blockade showed no significant effect on O2 uptake. We conclude that in patients with adequate depth of anaesthesia vecuronium-induced neuromuscular blockade does not lead to a further reduction of oxygen consumption, since muscular tone is already reduced by general anaesthesia.

Abdomen↗
PubMed1992

Imaging of pulmonary artery and vein anastomoses by transesophageal echocardiography after lung transplantation.

BACKGROUND: In patients after isolated lung transplantation, the postoperative course may be complicated by dysfunction of the pulmonary artery and vein anastomoses. METHODS AND RESULTS: Pulmonary artery and vein anastomoses in 11 transplanted lungs (four left, four right, and three bilateral lungs) in 10 patients were studied 1 day to 11 months after operation by transesophageal echocardiography (TEE). All 14 pulmonary vein anastomoses, all seven right (100%) and five of seven (71%) left pulmonary artery anastomoses could be visualized by TEE. Thrombosis of a left pulmonary vein anastomosis could be identified by TEE and successfully treated by thrombolysis. TEE detected a significant stenosis in one right and one left pulmonary artery anastomosis; anastomoses dysfunction were confirmed by cardiac catheterization and pulmonary angiography and successfully treated by surgical correction in both cases. CONCLUSIONS: Function and morphology of pulmonary artery and vein anastomoses in patients after isolated lung transplantation can reliably be assessed by TEE. In patients with suspected dysfunction of an anastomosis, TEE may be considered the diagnostic technique of choice.

Adult↗
PubMed1992

[Acoustic quantification--a new online procedure for automatic recording of left ventricular areas and area changes in the echocardiogram].

Initial experiences were obtained with a new technique for automatic quantification of left ventricular areas and area changes in two-dimensional (2D) echocardiograms (acoustic quantification, AQ). AQ is based on integrated back-scatter-analysis in real-time. Practicality and reliability of AQ were studied in 50 non-selected patients. AQ measurements of left-ventricular (LV) cavities were compared with off-line measurements which were obtained by analysis of videotaped images. Thirty-two (64%) and 39 (78%) patients could be studied by AQ from parasternal and apical views, respectively. LV areas measured from parasternal views or apical views showed a good correlation with corresponding values obtained by off-line analysis (r = 0.78 to 0.91). In addition, LV fractional area changes measured by AQ showed an excellent correlation with off-line measurements (parasternal: r = 0.86; apical: r = 0.84). During infusion of dobutamine (n = 3; 5, 10, 20 micrograms/kg/min, 10 min each dose), reduction of LV cavity areas could be continuously monitored and quantified by AQ for each cardiac cycle. In five of six patients who underwent transesophageal echocardiography, AQ could easily detect LV contours in the transgastric short axis view. Although AQ is not practicable in all patients, this new technique appears to be a promising and reliable approach for real-time, automatic boundary detection in 2D echocardiograms.

Adolescent↗
PubMed1991

Improvement in the diagnosis of abscesses associated with endocarditis by transesophageal echocardiography.

BACKGROUND: Echocardiography is recognized as the method of choice for the noninvasive detection of valvular vegetations in patients with infective endocarditis, with transesophageal echocardiography being more accurate than transthoracic echocardiography. The diagnosis of associated abscesses by transthoracic echocardiography is difficult or even impossible in many cases, however, and it is not known whether transesophageal echocardiography is any better. METHODS: To determine the value of transesophageal echocardiography in the detection of abscesses associated with endocarditis, we studied prospectively by two-dimensional transthoracic and transesophageal echocardiography 118 consecutive patients with infective endocarditis of 137 native or prosthetic valves that was documented during surgery or at autopsy. RESULTS: During surgery or at autopsy, 44 patients (37.3 percent) had a total of 46 definite regions of abscess. Abscesses were more frequent in aortic-valve endocarditis than in infections of other valves, and the infecting organism was more often staphylococcus (52.3 percent of cases) in patients with abscesses than in those without abscesses (16.2 percent). The hospital mortality rate was 22.7 percent in patients with abscesses, as compared with 13.5 percent in patients without abscesses. Whereas transthoracic echocardiography identified only 13 of the 46 areas of abscess, the transesophageal approach allowed the detection of 40 regions (P less than 0.001). Sensitivity and specificity for the detection of abscesses associated with endocarditis were 28.3 and 98.6 percent, respectively, for transthoracic echocardiography and 87.0 and 94.6 percent for transesophageal echocardiography; positive and negative predictive values were 92.9 and 68.9 percent, respectively, for the transthoracic approach and 90.9 and 92.1 percent for the transesophageal approach. Variation between observers was 3.4 percent for transthoracic and 4.2 percent for transesophageal echocardiography. CONCLUSIONS: The data indicate that transesophageal echocardiography leads to a significant improvement in the diagnosis of abscesses associated with endocarditis. The technique facilitates the identification of patients with endocarditis who have an increased risk of death and permits earlier treatment.

Abscess↗
PubMed1991

Anginal symptoms without ischemic electrocardiographic changes during ambulatory monitoring in men with coronary artery disease.

Episodes of angina pectoris without electrocardiographic (ECG) signs of myocardial ischemia during 24-hour ambulatory monitoring were studied in 128 patients with a history of stable angina, angiographically proven coronary artery disease and positive exercise test results. In all, 341 episodes of ischemic ECG changes (ST-segment depression greater than 1 mm for greater than 1 minute) and 190 episodes of angina pectoris were observed: 86 episodes consisted of both ECG changes and angina pectoris, 255 episodes consisted only of ECG changes, and 104 episodes only of angina pectoris. Duration and magnitude of ST-segment deviation and heart rate at the onset of ischemia were similar in the 86 symptomatic and the 255 asymptomatic episodes with ECG changes. The 104 episodes of angina pectoris without ECG changes were detected in 44 patients (34%) (group A); 29 of them had only episodes with angina pectoris and 15 patients had both--episodes of angina pectoris with and without ECG changes. In 84 patients (66%) (group B) angina pectoris without ECG changes was not observed; all episodes were accompanied by ischemic ECG changes in these patients. No differences in the angiographic extent of coronary artery disease and in exercise test data were seen in both groups A and B; however, maximal ST-segment depression during exercise testing was significantly greater in group B than in group A patients (2.4 +/- 0.8 mm vs 1.9 +/- 0.9 mm; p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

[O2 uptake and CO2 production during total intravenous propofol-alfentanil anesthesia under steady-state conditions. Is O2 uptake a parameter for assessing the depth of anesthesia?].

Depending on surgical and anaesthesiological procedures, anaesthesia leads to a reduction of O2 uptake (VO2), CO2 production (VCO2) and resting energy expenditure (REE). A controversial discussion on the degree of metabolic depression has continued in the literature fueled by a lack of studies in patients under standardised conditions. The goal of this study was to evaluate whether O2 consumption and/or CO2 production can be correlated to various depths of anaesthesia and whether VO2 could be a parameter to control narcosis. 12 patients (ASA I-II) scheduled for urological surgery of the lower abdomen, were given total intravenous anaesthesia with propofol and alfentanil. During a 60 minutes period the patients were first anaesthesized with an ED50 and then titrated to a dosage correlating with an ED95. The premedicated but awake patients each showed a REE which was about 10% below the calculated basal metabolism. Steady-state general anaesthesia led to an approximately 30% reduction of VO2, VCO2 an REE. Patients with adequate anaesthesia revealed no changes in oxidative metabolism with increased or decreased depth of anaesthesia. VO2 as a leading parameter proves to be problematic. It is useful as a measure for insufficient depth of general anaesthesia but fails to indicate overshooting anaesthesia depth.

Adult↗
PubMed1991

Circadian variation of myocardial ischemia in patients with stable coronary artery disease.

The circadian variation of myocardial ischemia detected during 24-h ambulatory electrocardiographic monitoring (AEM) was analyzed in 123 patients with stable angina pectoris, positive exercise test, and angiographically proven coronary artery disease. A total of 437 ischemic episodes (ST-segment depression greater than or equal to 1 mm and duration greater than or equal to 1 min) were observed; 333 (76%) episodes remained asymptomatic, and only 104 (24%) episodes were accompanied by anginal pain. Ischemic episodes predominantly occurred during the morning hours, between 6 a.m. and noon, and another smaller peak was observed in the afternoon, between 4 and 5 p.m.; this diurnal pattern was influenced neither by the extent of coronary artery disease nor the degree of left ventricular dysfunction. The circadian variation was restricted to the 345 (78%) ischemic episodes preceded by increases in heart rate; the 92 (22%) episodes without prior heart rate changes occurred randomly throughout the day. The morning peak in ischemic episodes was not associated with less myocardial oxygen supply; in contrast, heart rate profile showed parallel increases during the morning and afternoon hours, indicating elevated myocardial demand during these periods. Ischemia-related ventricular arrhythmias were concentrated during the morning hours, but their overall prevalence was low--28 (6%) of 437 ischemic episodes. These findings may provide further insight into the pathomechanisms of acute clinical events in patients with coronary artery disease, since the circadian variation of myocardial ischemia is very similar to that observed for the onset of myocardial infarction and sudden cardiac death.

Adult↗
PubMed1991

[O2 uptake in the recovery period. The effect of the anesthetic procedure and the postoperative administration of pethidine].

UNLABELLED: General anesthesia leads to a marked reduction in oxygen uptake (VO2), but during the recovery period O2 consumption can increase dramatically. A controversial discussion has continued in the literature concerning the role of different types of anesthesia with regard to metabolic changes. The aim of this comparative study was to evaluate the effects of two different techniques for general anesthesia and of postoperative meperidine on VO2, especially in the postanesthetic recovery period. METHODS: Twelve patients (K1: ASA class I-II, age: 39.9 +/- 16.1 years, height: 176 +/- 10.1 cm, weight: 76 +/- 12.8 kg) scheduled for urological lower abdominal surgery were given isoflurane-N2O-O2 (1.3 MAC); another group of 12 patients (K2: ASA class I-II, 35.9 +/- 14.5 years, 181.8 +/- 11.4 cm, 77.3 +/- 8.4 kg) received total intravenous anesthesia (TIVA) with propofol and alfentanil (ED95). Both groups were studied under steady-state conditions. Duration of anesthesia was 124.2 +/- 27.5 min (K2) versus 139.2 +/- 35.5 min (K1). VO2 was measured by an indirect calorimetric device (MMC Horizon, STPD). RESULTS: Preanesthetic values of VO2 were in the predicted range for basal metabolism. Steady-state general anesthesia led to approximately 30% reduction in VO2 (K1: 121-225 ml min, K2: 107-230 ml/min) compared to preanesthetic values (P less than 0.05). Both groups showed an increase in VO2 during the recovery period. When compared to the preanesthetic measurements, only K1 showed a statistically significant change. Shivering was observed during the recovery period in 8 patients in K1 (max VO2: 639 ml min) and 2 in K2 (max VO2: 584 ml min (P less than 0.05). Meperidine (25 mg i.v.) given to 5 patients from K1 because of postanesthetic shivering decreased VO2 significantly to the range of VO2 measured in K2. CONCLUSION: Oxygen consumption during general anesthesia was not defined by the type of anesthetic administered. During the recovery period however, VO2 depended on the type of anesthetic, as muscular hyperactivity was prominent in the isoflurane group. Meperidine could suppress visible shivering and reduce postoperative VO2 to the levels seen after TIVA.

Adult↗
PubMed1990

Circadian distribution of the characteristics of ischemic episodes in patients with stable coronary artery disease.

To determine the circadian distribution of episodes of myocardial ischemia, studies were performed in 111 patients with chronic stable angina pectoris, positive exercise test results and angiographically proven coronary artery disease. During 24 hours of ambulatory electrocardiographic monitoring, 101 symptomatic and 298 asymptomatic ischemic episodes (ST-segment depression greater than 1 mm, duration greater than 1 minute) were observed. The number of ischemic episodes and the cumulative duration of ischemia showed a circadian variation with the highest values between 8 and 10 A.M. and between 4 and 5 P.M. associated with a similar circadian variation of heart rate. Mean duration of ischemic episodes, maximal amplitude of ST-segment depression during ischemic episodes and increase in heart rate before the onset of ischemic episodes showed no significant circadian variation. Heart rate at the onset of ischemic episodes and maximal heart rate during ischemic episodes were lower between midnight and A.M. than during other times of the day. The morning and afternoon increase in ischemic activity is not paralleled by changes reflecting a decrease in myocardial oxygen supply during these periods (heart rate at onset of ischemia, heart rate increase before onset of ischemia), but is paralleled by a similar circadian variation of heart rate. The circadian variation in ischemic activity is predominantly based on a comparable variation in myocardial oxygen requirements.

Circadian Rhythm↗
PubMed1990

Incidence of ventricular arrhythmias during transient myocardial ischemia in patients with stable coronary artery disease.

To determine the incidence of ventricular arrhythmias related to episodes of transient myocardial ischemia during ambulatory electrocardiographic (ECG) monitoring, 97 patients with stable angina pectoris, angiographically proved coronary artery disease and an abnormal exercise test were studied. A total of 573 episodes with ST segment depression were documented: in 118 episodes (21%) the patients were symptomatic and in 455 (79%) they remained asymptomatic. Ventricular arrhythmias (greater than 5 premature ventricular beats/min, bigeminy, couplets or salvos of premature ventricular beats) occurred during 27 (5%) ischemic episodes in a subset of 10 patients (10%) (group A). The other 87 patients (90%) (group B) showed exclusively ischemic episodes without ventricular arrhythmias. Comparison of patients in group A and group B showed no differences in hemodynamic, angiographic, exercise testing and ambulatory ECG monitoring data. Ischemic episodes with and without ventricular arrhythmias showed a similar duration and amplitude of ST segment depression and a comparable heart rate at the onset of ischemia. Both types of ischemic episodes, with and without arrhythmias, occurred predominantly during the morning hours between 6:00 AM and noon, and both types remained asymptomatic to within similar percentages. The data demonstrate that ventricular arrhythmias are related to transient myocardial ischemia in only a few patients with stable angina pectoris; these arrhythmias are related neither to the degree of ischemia during ambulatory ECG monitoring nor to the occurrence of anginal symptoms.

Adult↗
PubMed1990

Silent ischemia, its clinical importance as seen in 1989.

Silent myocardial ischemia is defined as spontaneous episodes of ischemic equivalents, especially transient ST-segment depression without being accompanied by typical anginal pain. Due to the improved recording possibilities of the T-segment over 24 h, the phenomenon of silent ischemia was widely analyzed in recent years. The special methodological problems and, especially, newer clinical results (duration and daily number of episodes, circadian distribution of episodes) are extensively discussed; this also includes the correlation to coronary anatomy (extension of coronary artery disease) and to exercise testing. The prognostic aspects, and also the resulting therapeutic consequences and indications remain the objects of further studies; this is especially true for the indication for medical anti-ischemic treatment as analyzed by 24-h Holter monitoring.

Angina Pectoris↗
PubMed1990

[The recovery period following total intravenous anesthesia using propofol and alfentanil versus inhalation anesthesia using nitrous oxide and enflurane at 1.3 MAC].

Recovery of motor and mental functions were investigated in two groups with 20 young patients each. One group received total intravenous anaesthesia (TIVA) with propofol and alfentanil for urological surgery and the other group received nitrous oxide-oxygen anaesthesia in combination with 1.3 MAC of enflurane for lumbar nucleotomy. The following parameters were investigated before and up to 100 minutes after extubation: simple and discriminating motor activities, vigilance and short and long term memory. --Simple and in discriminating motor actions show a significantly faster recovery was seen in the TIVA group during the first 20 minutes after extubation compared to the enflurane-treated patients. Speech-related functions were particularly inhibited in the inhalational anaesthesia group. After 30 to 40 minutes the propofol-alfentanil group was able to meet all requirements while patients with inhalational anaesthesia needed 80 minutes to reach the same level. Recovery of short and long-term memory was also significantly shorter in the TIVA group. This clearly indicates a faster return of mental and motor functions following total intravenous anaesthesia with propofol and alfentanil. However the large dosages of alfentanil may be a problem with regard to post-anaesthetic respiratory depression. Further studies with larger numbers of patients will be necessary to evaluate the potential side effects of continuous propofol/alfentanil infusion. Presently, safety demands require, at least a sixty-minute post anaesthesia monitoring for patients receiving this new anaesthesia method.

Adult↗
PubMed1990

[Oxygen uptake and blood circulation parameters during anesthesia using EEG-assisted determination of anesthetic dosages].

Anaesthesia has significant effects on circulation and oxidative metabolism which are closely related to each other. Usually there is a marked reduction of oxygen uptake (VO2) and energy expenditure. A controversial discussion on the effects of the drugs administered and the degree of metabolic depression has continued in the literature fuelled by a lack of studies in patients under standardized conditions. 18 patients (ASA I-II) scheduled for major abdominal surgery were given closed-loop feedback control anaesthesia by quantitative EEG analysis. Group 1 received a total intravenous anaesthesia with methohexital and fentanyl whereas group 2 was given a combined anaesthesia with alfentanil and N2O. The aim of this comparative study was to evaluate the effects of different techniques for general anaesthesia on oxygen uptake and on the cardiovascular system. Preanaesthetic values of VO2 taken after flunitrazepam premedication were slightly below the predicted range determined by indirect calorimetry for basal metabolism. Steady-state general anaesthesia led to an approximately 30% reduction of VO2 for both groups. In contrast to oxygen uptake, blood pressure and especially heart rate were defined by the type of anaesthesia as in the methohexital fentanyl group higher values of both blood pressure and heart rate were observed.

Adult↗
PubMed1989

[High-dose single administration of isosorbide dinitrate: effect on diurnal distribution of transitory myocardial ischemia in patients with stable angina pectoris].

We studied the effect of a monotherapy of isosorbiddinitrate on symptomatic and asymptomatic ischemic episodes in 15 ambulatory patients with chronic stable angina pectoris, positive exercise test, and coronary stenosis greater than 70%. Transient ST-segment depression (greater than 0.1 mV for at least 1 min) was documented by 48-h Holter monitoring during a control period without anti-ischemic therapy and at the end of 14 days of treatment with 120 mg o.d. isosorbiddinitrate slow-release. In the control period, 68 asymptomatic and 28 symptomatic ischemic episodes were detected; most of the episodes occurred in the morning between 6.00h and 12.00h (41 episodes) and in the afternoon between 12.00h and 18.00h (36 episodes). Under anti-ischemic therapy the number of episodes and the total duration of ischemia was reduced by 46% and 53%, respectively (p less than 0.01). The anti-ischemic effect was most evident during the morning and the afternoon; the ischemic episodes during the evening and the night were not significantly diminished. It is concluded that in patients with stable angina pectoris a single high-dose of isosorbiddinitrate significantly reduces the number and duration of transient ischemic episodes during daily life.

Aged↗
PubMed1989

[Return of motor and mental functions following enflurane-nitrous oxide anesthesia of 1.3 MAC in various age groups].

Recovery of motor and mental functions we investigated in 60 patients at different age ranges (Group 1: 20 young patients between 20 and 35 years; Group 2: 20 middle-aged patients between 40 and 55 years) after nitrous oxide-oxygen anaesthesia in combination with enflurane of 1.3 MAC for lumbar nucleotomy. The following parameters were investigated before and up to 80 minutes after anaesthesia: simple and discriminating motor activities, the vigilance and the short and long term memory. In simple motor actions we noticed no significant differences between the three groups. By examination of discriminating motor activity, the functional capacity of Group 3 was significantly reduced in comparison to Groups 1 and 2. Nevertheless the efficiency in Group 2 was also decreased in comparison to Group 1. The postoperative vigilance was especially impaired in the elderly patients. Only 50% of the old patients were able to satisfy the asked requirements 60 minutes after extubation. The vigilance in Group 2 showed a better improvement compared to the elderly patients but was in comparison to the young patients significantly decreased. The long term memory of the old patients pointed out a considerable reduction after this kind of anaesthesia. While no distinct differences could be found between Group 1 and 2 40 minutes after extubation, a significant difference could be observed between Group 1 and 3 even after 60 minutes. The short term memory of the elderly and the middle-aged patients was considerably reduced 60 minutes after extubation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗