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Biomedical subjects

R Scherer

Publications and source records attributed to R Scherer.

At least 73 records · Page 4Linked to original sources
PubMed1992

[Management of the organ donor].

Brain death is associated with loss of hypothalamic, pituitary and brain stem function resulting in apnea, bradycardia and hypotension, poikilothermia, and diabetes insipidus. In order to preserve body functions mechanical ventilation is continued with the aim to maintain an arterial partial pressure of oxygen of more than 100 mmHg. Previous fluid restrictions and the application of diuretics during the treatment of high intracranial pressure frequently result in dehydration. Progressive vasodilation may induce severe hypotension and fluid replacement with cristalloids and if necessary colloids may be called for until the central venous pressure reaches 10 cm H2O. Continuous substitution of potassium and the use of hypotonic solutions such as glucose 5% may avoid hypokalaemia and hypernatraemia, respectively. Inotropic support with dopamine (5-10 micrograms/kg.min) or adrenaline (0.01-0.1 micrograms/kg.min) may be needed to maintain normal mean arterial blood pressure (65 mmHg). Polyuria (5000 ml/24 h) can be treated by continuous intravenous infusion of antidiuretic hormone (0.5-2-10 U/h). Hypothermia must be prevented by warming all fluids (37 degrees C) and covering the patient with heat saving blankets.

Brain Death↗
PubMed1992

[Massive natriuresis and polyuria after triple craniocervical subarachnoid hemorrhage: cerebral salt wasting syndrome?].

A thirty-year-old male patient suffered subarachnoidal haemorrhage from an angioma positioned in the cranio-cervical transition. After rebleeding twice the patient developed a hydrocephalus internus malresorptivus and excessive natriuresis and polyuria, accompanied by depressed renin activity and extremely low aldosterone plasma levels. Neither fluid restriction and sodium substitution, nor administration of hydro-chlorothiazide/indomethacin affected natriuresis and polyuria. It was only after treatment with fludrocortisone-acetate/hydrocortisone that hyponatraemia and polyuria were resolved. At the same time a ventriculo-peritoneal shunt was applied. Differential diagnosis excluded the syndromes of inadequate antidiuretic hormone secretion, renal and cerebral diabetes insipidus, osmotic receptor hypofunction, chronic renal dysfunction and tubular necrosis. Natriuresis and polyuria developed under dexamethasone therapy. Since patient history, physical examination and laboratory criteria could not explain the electrolyte and fluid imbalance, this might be attributed to the hydrocephalus. Similar disturbances have been reported from other patients with intracranial disorders. Mechanical pressure exercised on the hypothalamus might cause the disturbance of fluid and sodium balance. Assuming a cerebral salt wasting syndrome, a putative natriuretic factor coming from the brain or an imbalance in the cerebral renin-angiotensin-system, as described in rats and dogs, must be discussed.

Adult↗
PubMed1992

[The integration of thoracic epidural anesthesia into anesthesia for intra-abdominal surgery].

Upper abdominal and thoracic surgeries require efficient pain management. The complications of postoperative analgesia include respiratory depression and--when choosing the epidural route--possible damage to the spinal cord by infection, trauma, or bleeding. Therefore, thoracic epidural analgesia may appear to be too risky and is frequently cancelled although many studies have shown its excellent efficacy. Controlled studies comparing thoracic epidural analgesia to lumbar epidural analgesia or intravenous analgetic regimens with special regard to the patient's outcome are contradictory. To make the preoperative decision on the method of pain control more rational, we studied catheter-related complications from 2056 thoracic epidural catheters used for intra- and postoperative analgesia retrospectively (n = 1002) and prospectively (n = 1054) over a 5 1/2-year period. In all patients the thoracic epidural catheter was inserted preoperatively using local anaesthesia, in most cases by the paramedian approach between level T 5/6 and T 8/9. During the clinical course of all patients there were no clinical signs of any epidural bleeding or infection. Neurological complications caused by the epidural catheter did not occur. Seven patients (0.035%) experienced radicular pain that disappeared after removal of the catheter or interruption of the puncture, respectively. A primary perforation of the dura mater was noticed in 0.5% of cases retrospectively and 1.23% prospectively. Respiratory depression following epidural application of 0.3 mg buprenorphine was seen in 1 patient (0.05%). Continuous analgesia with local anaesthetics and/or opioids applied epidurally by a thoracic catheter was performed on the peripheral ward (n = 829, 40%) if close monitoring of the neurological status as well as rapid diagnosis of any painful paraesthesia or paraplegia was possible.

Abdomen↗
PubMed1991

[A fatal bleeding complication following central venous catheterization in end-stage pancytopenia. Medical and legal consequences].

An attempt to insert a central venous catheter into the internal jugular vein of a patient suffering from pancytopenia failed and due to massive bleeding into the cervical tissue the patient developed severe dyspnoea and died during unsuccessful endotracheal intubation. A five-year judicial inquiry finally discharged the anaesthesiologist revealing that forensic aspects like a valid patient's consent, exact documentation of operations and therapies, clear arrangement with patient's relatives as well as an early detailed written epicrisis play a major role. This may be the only way to early counteract medically inane causal relationship being presented by the relative's advocate. Especially in the patient at high risk central venous catheterisation requires strict checking the indication, the corresponding choice of the correct technique during venipuncture, and a sufficient haemostatic pretreatment and care after catheterisation.

Catheterization, Central Venous↗
PubMed1991

[Porto-femoro-subclavian bypass and the rapid infusion technique in orthotopic liver transplantation].

Veno-venous bypass during orthotopic liver transplantation is commonly performed as a porto-femoro-axillary bypass. Right-angle positioning of one patient's arm and surgical preparation of the femoral and axillary veins are necessary. In 17 patients and 20 consecutive orthotopic liver transplant procedures the common porto-femoro-axillary veno-venous bypass was substituted by porto-femoro-subclavian bypass with a percutaneous 20 F cannulation set (LAUB catheter, Cook). The 20 F catheter was introduced into the left subclavian vein by Seldinger's technique before the operation and was connected intraoperatively to the outflow tube of the biopump. Surgical preparation of the axillary vein was not performed. In 10 patients a Y-connector was used to connect up the Rapid Infusion System in addition. Postoperatively the catheter was left in place for 2-4 days. Introduction and removal of the catheter were uneventful in all cases. High blood flow through the catheter could be maintained by a low driving pressure of the pump (4000 ml/min; 100 mmHg). No intraoperative complications were observed. Shunt flows remained stable throughout the surgical procedure during the anhepatic stage. There was no bleeding from the puncture site, especially after removal of the catheter, though several patients had a poor coagulatory status in the early postoperative period. Two postoperative complications were observed: air embolism due to disconnection and formation of a thrombus at the catheter tip, which it was possible to remove together with the catheter itself. Installation of an irrigation infusion in the postoperative period and well-tightened connections help avoid such complications as thrombus formation, bleeding or air embolism.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

On the possibility of differential diagnosis at elevated erythrocyte sedimentation rate by analysis of the concentrations of blood plasma proteins--a model study.

An elevated erythrocyte sedimentation rate is generally regarded as an unspecific and mostly pathological indicator of inflammation or tumour. However, we have determined the concentrations of plasma/serum proteins that influence the erythrocyte sedimentation rate in numerous samples from several groups of patients with different diseases, including 2 forms of cancer. Equations have been developed by which the 1 h value of erythrocyte sedimentation rate can be expressed as the sum of disease-specific coefficients for each protein multiplied by the measured concentrations of the respective proteins. These equations are shown to be disease-specific with 64-93% probability. Such equations may thus form the basis for differential diagnosis.

Adult↗
PubMed1990

[Hemodynamics and myocardial energy balance in coronary surgery patients during high-dose fentanyl-pancuronium anesthesia and modified neurolept-pancuronium anesthesia].

In 8 patients with coronary artery disease (CAD) classed as NYHA II or III, anesthesia was induced with high-dose fentanyl (0.05 mg/kg) and pancuronium (0.1 mg/kg). The patients were ventilated normally with the aid of a mask (O2: air 1:1, tidal volume 10 ml/kg with a rate of 10/min) for 5 min and then intubated. In 8 further patients with CAD NYHA class II or III, anesthesia was induced with 0.02 mg/kg flunitrazepam, N2O/O2 1:1 and isoflurane 0.5 vol%; they were relaxed with pancuronium (0.1 mg/kg) in combination with a bolus of 0.005 mg/kg fentanyl. These patients were also ventilated normally for 5 min and then intubated. Measurements of cardiovascular dynamics included cardiac output (CO), heart rate (HR), arterial pressure (AP), pulmonary artery pressure (PAP), pulmonary capillary wedge pressure (PCWP), right atrial pressure (RAP), myocardial blood flow (MBF), and arterial and coronary sinus oxygen and lactate contents. Cardiac index (CI), stroke volume index (SVI), total peripheral resistance (TPR), myocardial oxygen consumption (MVO2), coronary vascular resistance (CVR), coronary perfusion pressure (CPP), myocardial oxygen content difference (AVDO2cor) and myocardial lactate extraction rate (LE) were calculated from standard formulas. Measurements and an electrocardiogram were taken before anesthesia, after induction of anesthesia and after intubation. The hemodynamic parameters HR, AP, CI, CPP were relatively stable in patients anesthetized with high-dose fentanyl and pancuronium, whereas we found greater decreases in these parameters with the balanced anesthesia technique. Determinants of myocardial oxygen demand were higher in the high-dose fentanyl group; therefore, myocardial blood flow and oxygen consumption did not decrease to the same extent as in the balanced anesthesia group.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1990

[A modified Macintosh blade with an angulated tip for difficult intubations].

The depth of the proximal part of a normal Macintosh blade was carved more shallow and the tip of the blade was made adjustable in its angle by means of a joint controlled by a screw-lock fixation via a small wire parallel to the blade. Clinical experience with this modified blade in 33 patients is reported. In 10 of 13 patients with severely reduced mouth opening less than or equal to 25 mm and 19 of 20 patients with a mouth opening greater than 25 mm, visibility during laryngoscopy with the modified blade was improved, compared to the normal Macintosh blade. The carved proximal part of the blade improves its maneuverability in a small mouth avoiding undue pressure on the incisors, the adjustable tip increases the blade's pressure on the base of the tongue lifting the epiglottis.

Anesthesiology↗
PubMed1989

Study of hepatotoxicity in isolated perfused liver versus cultures of rat hepatocytes.

Isolated perfused liver and cultures of rat hepatocytes were assessed for the quantitative evaluation of hepatotoxicity. Release of de novo biosynthesized plasma proteins and acid hydrolases into perfusion or culture media was taken as an indication of the integrity of hepatocytes in both systems. The activities of six acid hydrolases, alpha-L-fucosidase, alpha-D-galactosidase, beta-D-galactosidase, beta-D-N-acetylgalactosaminidase, beta-D-N-acetylglucosaminidase, and cathepsin D, were assayed in collagenase-segregated hepatocytes and in monolayer cultures of rat liver cells obtained via collagenase perfusion of rat liver. In situ, liver perfusion with collagenase led to a loss of 45 +/- 5% of the total acid hydrolase activity in the mitochondrial-lysosomal pellet of the liver cells with concomitant increase of these enzymes in the cytosol. In monolayer cultures over a period of 30 h, increased activity of cathepsin D, beta-D-galactosidase, and beta-D-N-acetylglucosaminidase in the mitochondrial-lysosomal pellet and the cytosol fraction was evident with concurrent biosynthesis of plasma proteins. The use of radioactive tracing techniques with the isolated perfused liver revealed that the rate of catabolism of intracellular protein was approximately 5 times that of plasma protein synthesis. Both methods described here are suitable for the study of the effects of toxins on the function of hepatocytes.

Animals↗
PubMed1988

Pulmonary edema due to partial upper airway obstruction in a child.

The case of an 8-year-old boy is reported, who developed acute pulmonary edema associated with acute subglottic swelling and subsequent partial upper airway obstruction after extubation and recovery from anaesthesia. The main factors responsible for the formation of pulmonary edema presumably are a large subatmospheric transpulmonary pressure gradient and hypoxia leading to translocation of circulating blood volume into the pulmonary vasculature and fluid shift across the alveolar-capillary membrane. Application of oxygen and CPAP or PEEP plus diuretic therapy will promote rapid clearance of the pulmonary edema.

Acute Disease↗
PubMed1987

[Moyamoya syndrome in neuroanesthesia].

Cerebrovascular moyamoya, occurring as a result of a sudden cerebrovascular insufficiency, represents an occlusive process - usually bilateral - at the termination of the internal carotid artery and the circulus arteriosus cerebri (circle of Willis). In this disease, a web of small collateral blood vessels in the post-stenotic area is seen in carotid angiography. We report on a female of 35 years of age with moyamoya confirmed by cerebral angiography whose anamnesis was typical of the condition. Surgical treatment consisted of anastomosis from the left superficial temporal artery to a cortical artery to enhance blood flow through the moyamoya network on the left side. The anaesthetic procedure followed by us is presented as an example of anaesthetic management of all surgical interventions in patients with moyamoya. The following factors are considered to be important: Avoidance of hypertensive as well as of hypotensive phases normoventilation; sufficient protection against mental stress; closely meshed long-term supervision. (In German literature, the "moyamoya syndrome" is also known as Nishimoto-Takeuchi-Kudo-Suzuki's-disease).

Adult↗
PubMed1986

[Systemic lupus erythematosus and hyper-IgE syndrome in a 13-year-old child].

In 1979, suspicion of convulsive disorder was diagnosed in a 9-year-old girl, who consequently underwent treatment with carbamazepine. In 1983, she developed hyperimmunoglobulinemia E syndrome. IgE values reached up to 5,400 u/ml. During the following weeks, we detected systemic lupus erythematosus with epimembranous glomerulonephritis histologically proved. The patient's immunological status does not allow the decision whether the lupus erythematosus may be classified as idiopathic or as a drug-induced disease having started with the convulsive disorder. Discontinuation of the carbamazepine therapy will not give a further hint on the etiology of the lupus erythematosus since long-lasting anticonvulsive therapy using this drug leads to an irreversible course of the disease.

Adolescent↗
PubMed1986

Pulmonary blood flow reduction by prostaglandin F2 alpha and pulmonary artery balloon manipulation during one-lung ventilation in dogs.

The purpose of this experimental study was to compare two methods of pulmonary blood flow manipulation during one-lung ventilation (OLV), either reducing pulmonary blood flow to the non-ventilated lung by inflation of a pulmonary artery catheter balloon (PAB) or by infusion of prostaglandin F2 alpha (PGF2 alpha). Seven anaesthetized dogs were intubated with a Kottmeier endobronchial tube and ventilated with 66% O2. Systemic and pulmonary pressures and blood gases, cardiac output and airway pressure were measured, and the venous admixture (QSP/QT) was calculated. During two-lung ventilation (TLV) Pao2 was 43.6 +/- 1.9 kPa (mean +/- s.d.) and (QSP/QT) was 11 +/- 3%. OLV reduced Pao2 to 12.1 +/- 1.6 kPa (P less than or equal to 0.001) and increased QSP/QT to 40 +/- 4% (P less than or equal to 0.001). Mean pulmonary artery pressure and airway pressure increased. PAB inflation caused an increase in Pao2 to 19.9 +/- 2.9 kPa (P less than or equal to 0.02) and a decrease in QSP/QT to 27 +/- 6% (P less than or equal to 0.001). PGF2 alpha infusion (1.2 micrograms kg-1 min-1) into the pulmonary artery of the non-ventilated lung increased Pao2 to 22.4 +/- 3.3 kPa (P less than or equal to 0.001) and decreased QSP/QT to 25 +/- 4 (P less than or equal to 0.001). PGF2 alpha infusion resulted in a small increase in mean systemic and pulmonary artery pressures. During the infusion of 1.2 micrograms kg-1 min-1 of PGF2 alpha no signs of bronchoconstriction were observed. PAB inflation and PGF2 alpha infusion were equally effective in improving oxygenation and reducing venous admixture during OLV.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1984

Clinical efficacy of low molecular weight heparin in postoperative thrombosis prophylaxis.

In a randomized controlled clinical trial, the efficacy and safety of two low molecular weight heparin ( LMWH ) fractions in the prophylaxis of deep vein thrombosis (DVT) were assessed. One hundred twenty-six patients undergoing major abdominal surgery received alternatively 2,500 APTT units b.i.d. of two LMWH fractions or 5,000 APTT units b.i.d. of an unfractionated sodium mucosal heparin ( UFH ). LMWH 2 differed from LMWH 1 by presenting a lower mean molecular weight and a higher anti-Xa/APTT ratio in vitro. Patients were randomly allocated to the three groups, and the development of DVT was studied with the 125I-fibrinogen uptake test ( RFUT ). The study was interrupted and the code broken prematurely because of otherwise unexplainable bleeding events. While no thrombosis and no severe bleeding were detected in the UFH group, three (7%) RFUT -positive DVT and two (5%) hemorrhagic complications occurred in the LMWH 1 group. No thrombosis and nine (22%) cases of severe bleeding were observed in the LMWH 2 group. Thus, the latter group differed significantly from the control group with regard to subjective and objective criteria for postoperative bleeding. Although these results do not allow general conclusions as to the value of LMWH fractions in the prevention of DVT, they indicate that these preparations just as ordinary heparin have a limited therapeutic range.

Adult↗
PubMed1984

[Tension pneumocephalus. A frequently misconstrued complication following neurosurgical operations].

Two cases of pneumocephalus are presented, complicating posterior fossa surgery in the sitting position and following craniotomy in the supine position. Intraoperative loss of cerebrospinal fluid, reduced cerebral volume and unnatural communications like fistulas and cerebrospinal fluid drainage are predisposing factors. Time and nitrous oxide tension affect the formation of the subdural air collection and its clinical symptoms, which are marked by a delay in the expected return to consciousness after operation or by postoperative deterioration of the neurosurgical status. CT scan or lateral skull X-ray lead to prompt diagnosis. Use of nitrous oxide is contraindicated in anaesthesia for surgical relief of tension pneumocephalus.

Adult↗
PubMed1984

[Pathophysiology and clinical aspects of single lung ventilation].

There are absolute and strong relative indications for provision of one-lung ventilation. The knowledge of the special physiology of one-lung ventilation as well as of the factors influencing hypoxic pulmonary vasoconstriction is necessary for adequate management of one-lung anaesthesia. Arterial hypoxaemia is a common complication of one-lung ventilation. Established techniques of treatment of hypoxaemia during one-lung ventilation are presented and several additional recent techniques are discussed.

Animals↗