Biomedical subjects
L Brandt
Publications and source records attributed to L Brandt.
[Assessing the depth of anesthesia using the electroencephalogram?].
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Prediction and prevention of delayed ischemic dysfunction in early aneurysm surgery.
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Aneurysmal subarachnoid hemorrhage: prevention of delayed ischemic dysfunction with intravenous nimodipine.
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Leukaemia and lymphoma risks derived from solvents.
Results of epidemiologic studies indicating an association between solvent exposure and the development of malignancies affecting haematopoietic and lymphatic tissues are reviewed. Clinical and cytogenetic data supporting this association are discussed. A variety of malignant disorders have been associated with solvent exposure, i.e. acute leukaemia, Hodgkin's disease (odds ratio 2.8-6.6), non-Hodgkin's lymphoma (odds ratio 3.3) and myeloma, and there are some indications that solvent exposure may be a risk factor for myelofibrosis. The carcinogenic effect of benzene is epidemiologically and experimentally well documented and there are some indications that other solvents may also be hazardous. Possible mechanisms bringing about malignant transformation are discussed. The need for further epidemiologic, cytogenetic and clinical studies on the association between solvent exposure and malignant diseases is emphasised.
Calvarial growth after linear craniectomy in scaphocephaly as evaluated by X-ray stereophotogrammetry.
An roentgen stereophotogrammetric system for the evaluation of skeletal adjustments following corrective surgery in craniosynostosis is described. Four illustrative cases of scaphocephaly, all treated with midline linear craniectomy, with uneventful postoperative follow-up periods of more than 4 years, are reported. The postoperative development, as evaluated by volumetric and kinematic analyses, was uniform but still rich in individual and local growth variations. This study confirms that roentgen stereometry ( = exact measurements from stereoradiographs), being an accurate and objective method, adds greatly to previous methods of postoperative assessment in craniofacial skeletal disorders.
Mitotic activity in non-Hodgkin's lymphoma. Relation to the Kiel classification and to prognosis.
At histopathological diagnosis of non-Hodgkin's lymphoma (NHL) the mean number of mitoses in 10 high power fields (X 40) was determined in thin sections (2 micron) and designated 'mitotic index' (MI). In 38 patients the thymidine labelling index (LI) of the lymphoma cells was also determined. There was a close correlation between MIs and LIs (r = 0.81, P less than 0.001) indicating that MI reflects the proliferative activity in NHL. Among 101 patients with NHL classified according to the Kiel nomenclature MIs were generally lower in lymphomas of low grade malignant type than in the high grade malignant lymphomas. The variation of MIs within morphological subgroups was especially pronounced in high grade lymphomas. Only 18 of 49 patients (37%) with MI greater than or equal to 2 have survived for 2 years in contrast to 37 of 52 patients (77%) with MI less than 2 (P = 0.001). For patients with histologically low grade lymphomas and MI greater than or equal to 2.0 the median survival was 23 months and for those with MI less than 2.0 58 months (P = 0.09). Patients with high grade lymphomas and MI greater than or equal to 2.0 had a median survival of 15 months compared to 57 months for those with MI less than 2.0 (P = 0.04). In a multivariate analysis of 50 patients with centroblastic-centrocytic (CB-CC) or centroblastic (CB) lymphomas the importance of different prognostic factors was analysed. Among the variables age, MI, growth pattern (follicular vs. diffuse), cell type (CB-CC vs. CB), clinical stage (I vs. II-IV), initial chemotherapy (active vs. less active) only age and MI gave significant prognostic information. It is concluded that the assessment of mitoses in NHL gives prognostic information in addition to histopathologic classification. The method is simple and the proliferative activity and histopathological diagnosis can be ascertained routinely on the same occasion.
Early effects of tetraethylammonium chloride on the contractile properties of isolated rabbit basilar arteries.
The acute vascular effects of tetraethylammonium chloride (TEA) were examined on annular segments of rabbit basilar arteries. Contractions induced by the potassium channel blocker were compared with those obtained for potassium chloride, 5-hydroxytryptamine (5-HT) and norepinephrine (NE). The greater magnitude of the contractions was of the following order: [K+] greater than 5-HT greater than TEA greater than NE. High concentrations of TEA alone (10(-2) M) generated spontaneous oscillatory contractions in cerebral vessels that were normally quiescent. Low concentrations of TEA (10(-8)-10(-6) M), which had no vasomotor properties per se, enhanced the contractile response of submaximal concentrations of 5-HT (10(-7) M) and NE (3 X 10(-6) M) and attenuated the contraction produced by 60 mM [K+]. An increased vascular response to the amines was still evident up to 3 h after the addition of TEA despite frequent rinsing with fresh buffer solutions. On arteries precontracted with TEA (10(-2) M), but not high [K+], the subsequent addition of 5-HT (10(-7) M) still induced a powerful constriction. Repeated concentration-response curves for [K+] were reproducible and, in the presence of TEA (10(-8) or 10(-6) M), the curve was displaced to the right in a competitive manner. A higher concentration of TEA (10(-4) M) was devoid of any blocking properties on the [K+]-induced response whereas, at 10(-3) M TEA, the response was potentiated, as evidenced by a shift of the curve to the left. Interactions between TEA and the cumulative response to 5-HT were difficult to interpret. Repeated exposures of the artery to 5-HT resulted in an increased maximal response with each determination (EAm = 127 +/- 9% and 149 +/- 14% of control values following the second and third applications, respectively). With TEA (10(-6) M), the increase in the maximal contractile effect noted previously was not observed. Contractions induced by single concentrations of TEA (10(-2) M) or [K+] (60 mM) were calcium dependent, were abolished completely in a calcium-free medium, and were depressed by the calcium antagonist nimodipine. 5-Hydroxytryptamine-induced contractions (10(-5) M) were less sensitive to withdrawal of calcium from the extracellular medium (31 +/- 6% relative to the maximal response at 4 mM calcium). Hence, an acute reduction in potassium conductance in cerebrovascular smooth muscle produced by TEA has complex, concentration-dependent effects and reproduces only part of the spectrum of effects of cisternal injection of blood on cerebrovascular reactivity.
Successful post-bypass ventricular assist with a centrifugal pump.
A 56 year old male with massive anterior wall infarction and development of a large aneurysm underwent aneurysmectomy and aorto-coronary bypass grafting to the RCA. Preoperative ejection fraction was 20%, LVedP was 30 mm Hg. During induction of anesthesia the patient sustained ventricular fibrillation and was successfully resuscitated. With the patient in progressive cardiogenic shock the operation was performed under emergency conditions. Despite adequate myocardial protection and cross-clamp time as well as prolonged reperfusion and balloon counterpulsation the patient could not be weaned off cardiopulmonary bypass. In this situation a centrifugal pump system was connected between the left atrium and the ascending aorta. With a pump flow of 5 l/min the patient was taken off cardiopulmonary bypass. After 20 hours of extracorporeal support without anticoagulation the device could be removed: explantation of the IABP followed 48 hours later. The patient gradually recovered and finally was discharged home in fair condition.
Survival following combination chemotherapy in advanced high grade non-Hodgkin's lymphomas: relation to proliferative activity of the lymphoma cells.
In 18 untreated adult patients (median age 62.5 yr) with advanced non-Hodgkin's lymphoma of unfavourable histology, thymidine labelling indices (LIs) of the lymphoma cells were assessed. The patients were treated with combination chemotherapy and have been followed for 29-60 (median 52) months or until death. The survival curve had a steep fall during the first 2 yr. Between 2-5 yr after treatment there was a flattening of the curve and survival seemed to be similar to the survival expected for a Swedish population matched for age and sex. 11 patients died with 2 yr and 7 patients have survived for a longer period. Age, histopathologic classification and clinical stages were comparable in short-term and long-term survivors and treatment was not more aggressive for the long-term survivors. The LIs were significantly higher (median 8.2) in short-term survivors than in the long-term survivors (median 1.4). Long-term survival following combination chemotherapy of advanced NHL of unfavourable histology seems to be achieved mainly in patients with a low proliferative activity of the lymphoma cells. It is suggested that in NHL a high proliferative activity may facilitate the generation of new mutants and that some of these are spontaneously resistant to various chemotherapeutic drugs.
Prediction and prevention of delayed ischemic dysfunction after aneurysmal subarachnoid hemorrhage and early operation.
Mean hemispheric cerebral blood flow (CBF) was studied after the intravenous administration of xenon-133 in 20 anesthetized patients with aneurysmal subarachnoid hemorrhage. Before early aneurysm operation, repeated CBF measurements were made to evaluate the cerebral vascular reactivity to controlled hyperventilation. Thirteen individuals received intravenous treatment with the calcium channel blocker nimodipine, whereas the other seven patients did not receive such specific antiischemic treatment. Five of the latter patients had an impaired CO2 response, and three showed delayed ischemic deterioration (DID), whereas none of the seven nimodipine-treated patients with impaired CO2 response showed DID. One nimodipine-treated patient with a preserved CO2 response, in whom operation was complicated, developed DID. The observed findings indicate that DID after uncomplicated early aneurysm operation may be associated with an early disturbance of cerebral vasoreactivity. Treatment with nimodipine may counteract the development of DID in patients with an impaired CBF CO2 response.
Ruptured middle cerebral artery aneurysm with intracerebral hemorrhage in younger patients appearing moribund: emergency operation?
Four women, aged 39 to 46 years, were urgently admitted to our neurosurgical unit after strokes. On admission, all appeared moribund, presenting with deep coma, pupils bilaterally dilated and fixed, decerebrate posture, and markedly abnormal respiratory patterns. Computed tomography revealed subarachnoid hemorrhage with an associated large intracerebral hematoma and pronounced shift of midline structures in all four cases. Because of the clinical appearance, the patients were given urea and were operated without preceding angiography. The origin of the hemorrhage was identified as a middle cerebral artery (MCA) bifurcation berry aneurysm in one patient and giant MCA aneurysms in the other three. The hematomas were evacuated, and the aneurysms were occluded. All four patients received intravenous nimodipine, none showed any sign of delayed ischemic deterioration, and all regained full consciousness within a few days. One patient died 3 weeks later from a pulmonary embolus. Three patients are presently at home with moderate focal neurological deficits and moderate to marked cognitive impairment. The psychosocial readjustment was very good in a patient with a left giant aneurysm, satisfactory in a patient with a right giant aneurysm, and unsatisfactory in a patient with a right berry aneurysm. The indications, ethical considerations, and technical aspects of operating on seemingly moribund patients who probably harbor a ruptured MCA aneurysm are discussed.
Cognition and adjustment after late and early operation for ruptured aneurysm.
Does early aneurysm operation, while lowering the overall management mortality, result in an unacceptable morbidity in terms of increased cognitive disturbances and psychosocial maladjustment? The present study evaluates quality of life, degree of cognitive dysfunction, and adjustment of 93 patients with satisfactory neurological recoveries after operations for ruptured supratentorial aneurysms. All patients had been in neurological Grades I to III (Hunt and Hess) after subarachnoid hemorrhage (SAH). Fifty-five patients were operated upon during the acute state, i.e., within 72 hours after bleeding (early surgery = ES), and 38 patients had been subjected to late surgery (LS), i.e., were operated on 9 days or more after SAH. Each patient was subjected to a clinical interview and a comprehensive neuropsychological investigation. The time interval between SAH and assessment varied between 12 and 103 months (mean, 56 months). The results confirm that there are indication of cognitive malfunctioning and psychosocial disturbances of varying severity and distribution in patients who have undergone LS. The pattern and distribution of sequelae after LS did not differ substantially from that in patients subjected to ES. The results offer strong support to the concept that remaining disturbances in cognition are mainly related to the impact of the initial hemorrhage per se. In patients with anterior communicating artery aneurysms, a larger decrease in tempo and perceptual vigilance was noted, suggesting that the subfrontal midline structures are particularly involved in processes demanding flexibility, attention, and capacity to adapt to novel demands in a perceptual situation.
Management of ruptured intracranial aneurysm: a review.
The discouraging history associated with management of aneurysmal subarachnoid haemorrhage (SAH) is reviewed along with improvements in outlook attributable to progress made within the past decade. Among the new developments is the introduction of microsurgical techniques that allow elective surgery in the acute stage thereby preventing repeat haemorrhages. Early operation also offers the possibility of a more aggressive pharmacological anti-ischaemic treatment. Notwithstanding the improved results of acute elective surgery and the fact that delayed ischaemic deterioration (symptomatic cerebral vasospasm) now may be almost eliminated, the overall outcome remains gloomy. Despite recent advances not more than one out of three individuals, who are struck by the rupture of an intracranial aneurysm, may be expected to make a good neurological and functional recovery. Hope for further improvements may depend on the development of techniques that can identify intracranial aneurysms before they rupture and increased knowledge of the aetiology of such arterial wall lesions.
[Comparative clinical study of nalbuphine and fentanyl. Effects and side effects with special reference to the induction phase].
In a previous study concerning balanced anesthesia we realized that the adrenergic sympathetic reaction caused by intubation could not be suppressed by nalbuphine-HCl (NAL), a new narcotic agonist-antagonist in the same way as by fentanyl (FE). The aim of the study was to investigate whether the observed autonomic reaction could be overcome by: (a) varying the interval between injection of NAL and intubation or (b) increasing the induction-dose of NAL. MATERIALS and METHODS. After receiving institutional approval and the patients' written informed consent, a two-part randomized trial arrangement was made using two groups of 10 surgical patients each. During the first part the induction-dose of NAL was 1.5 mg/kg BW and that of FE was 0.005 mg/kg BW. Midazolam 0.15 mg/kg BW was the induction hypnotic. Orotracheal intubation was performed 15 min after NAL and 10 min after FE injection. During the second part, the NAL dosage was 2.5 mg/kg BW and intubation was carried out 10 min after opiate injection. Induction conditions in the FE group were unchanged. RESULTS. NAL causes adrenergic sympathetic hemodynamic and autonomic reactions immediately after injection (Figs. 1a + b, 2a + b). The rate-pressure product increase during intubation is significantly higher after NAL than after FE administration and cannot be suppressed by increasing the dosage or increasing the injection-intubation interval. In contrast, the postoperative period is characterized by long-lasting analgesia (114 min vs 82 min in the FE group) and sedation, especially after administration of 2.5 mg/kg BW NAL. CONCLUSION. These results may be explained by the agonist-antagonist activity of NAL at the opiate receptor sites.
The first reported oral intubation of the human trachea.
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[Clinical experiences with a new reusable pressure transducer].
Invasive blood pressure monitoring is increasing in anesthesia and intensive care. Compared to noninvasive methods, it has some decisive advantages: (1) blood pressure trends can be assessed beat by beat, which is important especially in situations of cardiac arrhythmia; (2) respiratory changes in blood pressure as one sign of hypovolemia can be detected easily; and (3) pressure changes induced by the autonomic nervous system become apparent. We studied a new, reusable pressure transducer system, the Medex Novatrans-MX800 in routine intra- and postoperative monitoring of patients undergoing cardiac surgery using the following criteria: (1) handling; (2) accuracy of measurement; (3) durability; and (4) costs. The system is easy to use and has a low susceptability to breakdown. In 29 of 31 transducers tested, the error of measurement over a range of 0-150 mmHg was less than 2% as reported by the manufacturer. Two transducers showed errors of measurement over 5% after 60 times of reuse. The mean reusability rate until the transducer became defective was 75.8 +/- 17.3 in the operating room (19 transducers tested) and 59.7 +/- 29 in the intensive care unit (12 transducers tested, 11 still in use). A comparison of costs shows that the Novatrans-MX800 system is the cheapest system for invasive pressure monitoring available at this time.