Search PubMed⌕ Search

Biomedical subjects

L Brandt

Publications and source records attributed to L Brandt.

At least 163 records · Page 9Linked to original sources
PubMed1989

[Improvement of oxygenation in thoracic surgery with one-lung ventilation using a new intraoperative CPAP device].

For thoracic surgery with one-lung ventilation, the use of CPAP for the non-ventilated lung can improve oxygenation. We studied the use of a newly developed CPAP device in 28 patients undergoing single-lung ventilation. This device was easy to use, in particular because the components are familiar to every anesthesiologist. The use of +5 mbar CPAP improved oxygenation by an average of 39.5 mm Hg; +10 mbar CPAP brought about an improvement of 89 mm Hg. Pulse oximetry proved useful in monitoring adequate oxygenation.

Humans↗
PubMed1989

[The use of pulse oximetry in detecting disorders of the arterial oxygen status in the immediate postoperative phase exemplified by combination anesthesia with isoflurane].

Adequate respiratory monitoring should immediately indicate deteriorations of arterial oxygen status, e.g. hypoxia (paO2-decrease [mmHg]), hypoxaemia (caO2-decrease [ml/dl]) and hypoxygenation (saO2-decrease [%]). These alterations have been detected in the early postanaesthetic period only by the classical clinical criterias cyanosis and tachycardia. Therefore, O2-application often is recommended for the first 10 min postoperatively. Nevertheless oxygen therapy as well as discharge from the recovery room both are dependent on the anaesthetist's judgement. It was the aim of this study to evaluate incidence and criterias of postanaesthetic hypoxygenation following balanced anaesthesia with isoflurane and to estimate both the actually most valid parameter (psO2) and the monitoring of choice (pulse oximetry). Postoperative hypoxygenation (psO2 less than 90%) occurred in 36% within the total of 50 patients. A correlation between hypoxygenation and sex, age, smoking habits and ASA-classification (groups I and II) could not be detected. In conclusion postanaesthetic hypoxygenation must be considered as being influenced by a widespread number of different factors. It's occurrence therefore, seems to be unpredictable. Hypoxygenation can easily be avoided by application of O2 (31/min) over at least 40 min. Cyanosis and tachycardia are not suitable for recognition of hypoxaemia caused by periodically occurring hypoxygenations. With respect to the limitations of the method (measurement of arterial O2-saturation in peripheral circulation using pulse wave as an inflow indicator of arterial blood into the capillary bed; increased Hb-derivative concentrations, e.g. COHb), pulse oximetry for estimation of partial O2-saturation (psO2) seems to be the respiratory monitoring of choice in the early postoperative period. In that sense it is superior to pO2 but inferior to saO2 and caO2.

Adult↗
PubMed1989

[Pharmacokinetic profile and bioavailability of a new pharmaceutical formulation of isosorbide-5-mononitrate sustained-release formulation].

The pharmacokinetic profile and the bioavailability of a new galenic formulation of isosorbide-5-mononitrate sustained released capsules (Olicard 40 retard) was tested under standardized conditions. 12 healthy, male volunteers (mean age 24.9 +/- 3.0 years) in a randomized, intraindividual crossover design (wash-out phase: 6 days) received the isosorbide-5-mononitrate sustained-release capsules (testformulation) and a standard-release formulation of the same active substance as single dose (40 mg each). Venous blood sampling for analysing the plasma concentration of isosorbide-5-mononitrate was done before and at 21 fixed times after medication. The AUC0----36h of the concentration/time curve was calculated using the linear trapezoidal rule and the AUC0----infinity extrapolated after computing the half-life of the terminal elimination phase. The leading variable was the AUC0----infinity. For the sustained-release preparation an AUC0----36h of 5764.5 +/- 909 ng/ml.h was measured, an AUC0----infinity of 5863.9 +/- 981.9 ng/ml.h was calculated, with a peak maximum (Cmax) of 472.5 +/- 29.7 ng/ml after 2.9 +/- 0.5 h (tmax). For the standard-release formulation an AUC0----36h of 5679.8 +/- 690.3 ng/ml.h was measured, an AUC0----infinity of 5688.7 +/- 695.7 ng/ml.h was calculated, with a peak maximum (Cmax) of 842.4 +/- 100.2 ng/ml after 1.2 +/- 0.2 h (tmax). The bioavailability of the standard-release formulation was postulated to be 100%. The non-parametric calculation of the bioavailability-ratio (geometric Walsh-averages) was 101.47% (95% confidence limits 85.24% to 121.09%). There was no statistically significant difference between the both galenical formulations, the sustained-release preparation has no influence on the total amount of resorption.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

[The washout behavior of isoflurane following balanced anesthesia and its effect on postoperative oxygen supply].

Few studies have described the pharmacokinetics and pharmacodynamics of isoflurane (I) during the postoperative recovery room stay. In this study the influence of balanced anesthesia with I on the postoperative course was investigated by studying pulmonary washout of I and its effect on arterial oxygen saturation. METHODS. Following institutional approval and informed consent, 50 patients (ASA I and II) scheduled for lateral fenestration for intervertebral disc herniation participated; all had no previous record of cardiopulmonary problems. Induction of anesthesia was achieved with intravenous alcuronium 0.03 mg/kg, fentanyl 0.003 mg/kg, thiopental 5 mg/kg, and succinylcholine 1.5 mg/kg followed by alcuronium 0.09 mg/kg before changing to the prone position. Anesthesia was maintained with controlled ventilation in a rebreathing system (fresh gas flow FGF) = 3.01/min, FIO2 = 0.3 in N2O, plus 0.8 Vol.-% cIet = 1.3 MAC). Near the end of surgery I was discontinued and IGI was increased to 61/min O2 for 10 min. Patients then returned to breathing ambient air. Extubation was carried out as soon as a minimum tidal volume of 400 ml was obtained. End tidal I concentration (cIet; Vol.-%) was measured by infrared absorption (Normac, Datex) and O2 saturation by pulse oximetry (Biox III, Ohmeda). Datum point of the pulmonary I-washout curve was the mean end-tidal I concentration obtained 15 min before terminating I (cIAW). Effects of duration of anesthesia, Broca index, and amount of I administered (tidal volume x inspiratory I concentration x min; ml) on I-washout were assessed. A pulse-oximetric O2 saturation of less than 90% was regarded as hypoxygenation. RESULTS. Mean duration of anesthesia for both males and females was 85 +/- 25 min, mean Broca index 102 +/- 13. The amount of I administered with the inspiratory volume was 5.661 +/- 2.194 1 I (1.0 +/- 0.4 Vol.-%). Mean I-regression (Fig. 3) was 236 x 10(-5) Vol.-%/min (Figs. 1 and 3). Mean I-washout 60 min after extubation was 44.6 +/- 15.2% of the administered amount. Adequate spontaneous breathing began a mean of 17 min after the end of I exposure, corresponding to 20% cIet of washout. All patients were extubated after a mean of 22 min at a mean etI of 17% of washout. After extubation, pulse oximetry indicated hypoxygenation in 18 patients (= 36%) during 2 periods (Fig. 4): (1) at a mean cIet of 0.1 Vol.-% (= 15% of washout) after a mean of 8 min; and (2) at a mean cIet of 0.08 Vol.-% (= 12% of washout) a mean of 19 min following extubation. Further episodes of hypoxygenation occurred as much as 40 min post-extubation. (ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1988

Cerebrovascular and cerebral effects of nimodipine--an update.

A survey is given on the vascular and neuronal effects of calcium antagonists under physiological and pathological conditions. Special emphasis is put on vasospasm caused by subarachnoid haemorrhage and on postischaemic cerebral hypoperfusion following different forms of cerebral ischaemia, and on the attempts to influence these phenomena pharmacologically. Regarding its neuronal effects it seems likely that nimodipine potently blocks calcium entry during pathological conditions like cerebral ischaemia and spreading cortical depression. Positive effects also have been seen during epileptic seizures and withdrawal syndromes, whereas calcium entry under normal physiological conditions does not appear to be affected. Possible clinical consequences are discussed.

Animals↗
PubMed1988

Does intravenous nimodipine treatment influence cognition in patients subjected to early aneurysm operation?

Following aneurysmal subarachnoid hemorrhage (SAH) many patients complain of and exhibit disturbances of a cognitive nature. The etiology behind this encephalopathy is less well understood. Disturbed CSF-hydrodynamics and/or spasm in the lentriculostriate and thalamoperforating vessels might be responsible for such disturbances. This study comprised 56 patients subjected to early aneurysm operation, of whom 21 received intravenous nimodipine during the critical phase for SAH-induced vasoconstriction. There was no difference in cognitive disturbances measured with a specifically conceived battery of psychometric test instruments 2 years or more after SAH and surgery.

Adult↗
PubMed1988

Thromboxane B2 levels in serum during continuous administration of nimodipine to patients with aneurysmal subarachnoid hemorrhage.

Twenty-four patients with subarachnoid hemorrhage due to rupture of a supratentorial aneurysm underwent surgery within 72 hours after subarachnoid hemorrhage. Immediately after clipping of the aneurysm the patients were treated with intravenous nimodipine for at least 7 days and then received the drug orally for another week. Nine patients had a documented or probable intake of aspirin or other nonsteroid anti-inflammatory drug during the days preceding admission. In all patients there was a gradual increase in serum thromboxane B2 concentration from low to normal levels during the treatment period, the increase being most pronounced in patients with prior nonsteroid anti-inflammatory drug intake. Thromboxane B2 concentrations were similar to those of four control patients not receiving nimodipine. In three patients who developed delayed ischemic dysfunction despite "therapeutic" nimodipine plasma concentrations, the thromboxane B2 levels were low or normal. Our present results do not support the idea that nimodipine exerts an effect on platelet function in patients with aneurysmal subarachnoid hemorrhage.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1988

Aneurysmal subarachnoid haemorrhage: overall outcome and incidence of early recurrent haemorrhage despite a policy of acute stage operation.

A series of 480 patients who were alive upon admission following an aneurysmal subarachnoid haemorrhage (SAH) is reported. These patients represented 40% of the total Swedish incidence during a 3-year period. The three neurosurgical referral centres covering this population had a similar policy of early diagnosis and acute state surgery in all patients considered of having a potential to survive without permanent disabling cerebral malfunction. At 2-year follow up 45% showed a good neurological recovery, the morbidity was 25% and the mortality was 30%. Some more lives might have been saved with an improved ultra-early referral system since there were 21 initially good-to-fair risk patients (4% of the total SAH population) who rebled fatally before surgery and within 48 h. For comparison, in the Kingdom of Denmark, with a general policy of delayed operation, out of 1076 patients who were alive upon admission, 27.5% made a good recovery, while the morbidity was 27%, and the mortality was 45.5%.

Humans↗
PubMed1988

Risk of non-Hodgkin's lymphoma among men occupationally exposed to organic solvents.

An occupational history of exposure to organic solvents, defined as daily occupational exposure for at least one year, was more common among 167 men with newly diagnosed non-Hodgkin's lymphoma than among 130 healthy referents from the general population (38 versus 14%). Categorization in five-year age groups gave 3.3 as a Mantel-Haenszel estimate of the odds ratio (95% CI 1.9-5.8). The odds ratio was 6.5 (95% CI 3.2-13.3) for localized supradiaphragmatic tumors and 2.3 (95% CI 1.3-4.3) for other lymphoma presentations. In a logistic model including age and organic solvent, phenoxy acid, and chlorophenol exposure, it could be shown that solvent exposure was an independent risk factor and that no important interaction occurred between the risk factors. With increasing duration of exposure there was a significantly increased risk of lymphoma, a finding implying a dose-response relationship. There was no significant difference in tumor histology between the exposed and unexposed patients. These findings support the concept that occupational exposure to organic solvents is a risk factor for non-Hodgkin's lymphoma. The results also confirm a strong association between such exposure and an initial supradiaphragmatic location of the lymphomas.

Adult↗
PubMed1988

[Short-lasting infusions of Fibraccel following aortocoronary bypass surgery. The effect on postoperative blood loss and hemostasis depending on the time of extracorporeal circulation].

Bleeding is a major problem in the post-operative period (p.o.) after aortocoronary bypass surgery. Harke et al. have investigated the beneficial effect of homologous phospholipid complex (Fibraccel) after mitral and/or aortic valve replacement. No actual data were available evaluating therapy with Fibraccel after aortocoronary bypass grafting. We were especially interested in the influence of Fibraccel on routine blood coagulation parameters: partial thromboplastin time (PTT), thrombin time (TT), prothrombin time = Quick fibrinogen, platelet count and activated clotting time, spontaneous platelet aggregation (alpha 2/Tr, platelet aggregation test II of Breddin), thrombelastography, blood loss from the chest drain, use of fresh frozen plasma, and side-effects of the substance after aortocoronary bypass grafting. Forty patients (6 female, 35 male, mean age 58 years, ASA III-IV) were studied in a randomized order. Patients who had acetylsalicylic acid (ASS) or anticoagulants during the last 7 days before operation were excluded. In 20 patients 50-ml Fibraccel infusions lasting 30 min each were started immediately after antagonism by protamine chloride. Subsequent 50-ml Fibraccel infusions were given every 4 h until 20 h after extracorporeal circulation (ECC). The other 20 patients received placebo infusions at corresponding times. Each patient had a routine ASS medication (0.5 gi.v) about 8 h p.o. Blood samples for immediate analysis were taken: I = before operation; II = after ECC, before protamine; III = 90 min after protamine; IV = on the first p.o. day (20.5 h after protamine).(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Coagulation↗
PubMed1988

[Frequency and severity of throat complaints following general anesthesia with the insertion of various endotracheal tubes].

Laryngeal and pharyngeal complaints following general anaesthesia are well-known problems. The frequency, extent, and intensity reported in several studies are at variance. Such transient postoperative problems should not be considered equivalent to traumatic airway injuries caused by endotracheal intubation. A decrease in the incidence of slight airway complications was to be expected with the introduction of low-pressure-cuff tubes, however a few studies have reported just the opposite result. This study was designed to investigate the incidence, intensity, and duration of postoperative airway symptoms with special emphasis on cuff construction (low-pressure-high-volume cuff (LPC) vs high-pressure-low-volume cuff (HPC)). Our double-blind study included 500 patients. The acceptance criteria were: operation outside the head and neck region, no throat pack or gastric tube. The subjects were divided randomly into five groups, each group consisting of 100 patients: Group A: red rubber tubes (HPC); Group B: latex-spiral tubes (HPC); Group C: PVC tubes (LPC); Group D: PVC tubes with rediffusion system (LPC); Group E: face mask. The patients of groups A-D underwent oral intubation using lidocaine gel 2%; adequate cuff inflation was determined just after intubation. The patients were questioned every 24 h for 2 days postoperatively using an analogue scale and "open" and "closed" questions. The single groups were comparable in age, sex, height, weight, number of smokers, duration of operation (only groups A-D), and preoperative diseases of the upper airways.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Comparison of MR imaging and CT in patients with intracranial aneurysm clips.

CT and MR imaging of the brain were performed without complications in 16 patients who had undergone surgery for a ruptured aneurysm with the use of nonferromagnetic Yasargil 316 or Sugita Elgiloy clips. MR was performed on a 0.3-T Fonar beta-3000M imaging system. The artifacts caused by the clips were smaller on MR than on CT, and, therefore, anatomic structures such as the brainstem and temporal lobes were better visualized on MR. Brain-tissue lesions corresponding to the frontotemporal surgical approach were seen with MR in seven patients and with CT in six. In three patients temporal-lobe lesions seen on MR were not seen on CT because of beam-hardening artifacts. Lesions unrelated to the region of surgery were seen with MR in nine patients and with CT in five. In conclusion, MR was safe and superior to CT both in demonstrating anatomic details and in detecting tissue lesions in patients with aneurysm clips.

Alloys↗
PubMed1988

[In vivo detection of the Christiansen-Douglas-Haldane effect in clinical conditions].

The Christiansen-Douglas-Haldane effect, also termed Haldane effect, describes the dependence of CO2 absorption by blood on the degree of hemoglobin oxygenation. Under the physiological condition of an "open" system between blood and alveolus, the arterial partial pressure of CO2 (paCO2; mmHg) must range below the mixed-venous (pvCO2; mmHg) value. During the nonphysiological situation of a "closed" system, e.g. hyperoxic apnea after adequate pre-oxygenation (O2 uptake with lack of CO2 delivery), paCO2 can assimilate to pvCO2 and even exceed it. The remainder has often been termed a "paradoxical phenomenon". It was the aim of this study to prove the Haldane effect in vivo in the "closed" system of hyperoxic apnea. Eighty patients (ASA II-IV, NYHA II-III) scheduled for coronary surgery gave written informed consent and were examined. Following the preparations for induction (venous and arterial cannulas, pulmonary artery catheter), they were pre-oxygenated with 6 l O2/min until induction of anesthesia was achieved. Pre-oxygenation was maintained actively/passively until intubation. At the onset and the end of intubation the arterial (a) and mixed-venous (v) blood gas status (pHa, pHv, saO2 and svO2 (%), paO2 and pvO2, paCO2 and pvCO2 were determined using the Corning 170 pH/blood gas analyzer and the Corning 2500 CO-oximeter. Statistical analysis of the data was based on Student's t-test for paired samples. Periods of apnoea ranged between 60 and 180 s. The data were allocated to three groups, depending on the duration of apnea: Group I: 60-100 s; Group II: 101-140 s; Group III: 141-180 s.(ABSTRACT TRUNCATED AT 250 WORDS)

Apnea↗
PubMed1988

[Effect of different pre-oxygenation procedures on arterial oxygen status].

There are different opinions regarding efficiency, duration, and techniques of preoxygenation. It was the aim of our study to systematically investigate the effectiveness of different preoxygenation methods by means of arterial blood gas parameters (paO2, SaO2, and CaO2). METHODS. After receiving informed consent, 80 patients undergoing coronary bypass grafting (NY-HA II-III, ASA III-IV, mean age 57 years) were randomized in eight groups, each with a different preoxygenation technique (Table 1). During normocapnic preoxygenation (Table 2), the following parameters were compared: duration of preoxygenation (3 vs. 5 min), manner of holding the face mask (tightly fitting vs. one digit away from mouth and nose), and oxygen flow (6 vs. 10 l/min) via anesthesia circuit system. Arterial blood gases were analyzed with a Corning 170 pH/blood gas analyzer and a Corning 2500 CO-oximeter. For statistical analysis Student's t-test was used. P less than or equal to 0.01 was considered to be significant (*). RESULTS. As Fig. 1 shows, the different preoxygenation techniques affected paO2 values differently: oxygen flow had a greater influence than duration of preoxygenation. Most important was the manner of holding the face mask. With a tightly fitting mask, preoxygenation was more effective than with the face mask one digit away from mouth and nose, independent of preoxygenation time and oxygen flow (Table 3). The SaO2 (Fig. 2) increased in the same manner with the different preoxygenation techniques from 94.0% to 97.5% (Table 3); CaO2 (Fig. 3) was influenced in a similar way (16.7 ml/dl to 17.4 ml/dl).(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Gas Analysis↗
PubMed1988

[Plasma cortisol in experimental anesthesia with halothane, enflurane, isoflurane and nitrous oxide].

The influence of anesthesia on plasma cortisol has most often been studied in connection with routine operations. To investigate the specific effects of modern inhalation anesthetics more accurately, we examined the specific effects of four inhalation anesthetics on human plasma cortisol during volunteer studies on the influence of anesthetics on the electroencephalogramm. METHODS. A group of 17 (10 m, 7 f) young healthy volunteers who had not received any premedication and were not intubated were studied after informed consent had been obtained. In the first series of experiments the concentration of halothane, enflurane, isoflurane or N2O was increased to MAC (minimal alveolar concentration) 0.5 for a 15-min steady-state period. Blood samples were taken 5 min prior to induction (I), 35 min after induction, on steady-state MAC 0.5 (II), and 15 (III) and 35 (IV) min after the end of anesthesia. In a second series, with 5 subjects, the concentration of halothane, enflurane or isoflurane was first increased to a steady state of MAC 1.0. After reduction to MAC 0.5 steady-state, anesthesia was supplemented with 53% N2O to give a steady state of MAC 1.0 again. Blood samples were taken 5 min prior to induction (I), after the attainment of steady-state MAC 1.0 (II), 35 min later at MAC 0.5 (III), 40 min later at MAC 1.0 with volatile anesthetic/N2O (IV), and 15 (V) and 35 (VI) min after the end of anesthesia. RESULTS. MAC 0.5 N2O produced a marked rise in mean plasma cortisol, from 64.2 micrograms/l to 164.5 micrograms/l.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗