Search Results - (Author, Cooperation:F. Frei)

2013-09-13

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Arsenic/*analysis ; Arsenic Poisoning ; Carbon/analysis ; Drinking Water/chemistry ; Food Contamination/analysis ; Geologic Sediments/chemistry ; Groundwater/analysis/*chemistry ; Humans ; Oxidation-Reduction ; Rivers/chemistry ; Silicon Dioxide/analysis/chemistry ; Vietnam ; Water Movements ; Water Wells/chemistry

1365-2044

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Children with cerebral palsy and severe mental retardation who present for operation may require lower concentrations of inhalational anaesthetics than healthy children. The minimum alveolar concentration (MAC) for halothane was measured in 36 children and adolescents, aged 4–18 years, who underwent orthopaedic surgery. The control group consisted of 12 healthy children (group 1). Children with cerebral palsy and severe mental retardation were allocated to one of two groups: those taking chronic anticonvulsant medication (group 2) (n = 12) and those who did not take any drugs (group 3) (n = 12). The mean (SEM) MAC value for halothane (expressed in volume per cent) was 0.90 (0.02) for healthy children. Children with cerebral palsy had significantly lower MAC values whether they took anticonvulsant drugs or not (0.62 (0.03) and 0.71 (0.10), respectively).

Electronic Resource

0091-3057

Anxiogenic drugs ; Anxiolytics ; Elevated plus-maze ; Factor analysis ; Rats

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Chemistry and Pharmacology

Medicine

Electronic Resource

1433-0474

Schlüsselwörter ARDS ; NO ; Respiratory-syncytial-Virus ; Pulmonale Hypertension ; Atemversagen ; Key words ARDS ; Respiratory syncytial virus ; Respiratory failure ; Pulmonary hypertension

Springer Online Journal Archives 1860-2000

Medicine

Summary Background: Inhaled nitric oxide (iNO) has been used to improve oxygenation in adults and children with acute respiratory distress syndrome (ARDS) since several years. Previous studies on the effect of iNO in patients with ARDS were usually lumped together with respect to causation. Methods: We describe the acute effect of iNO in 4 children (age 4–54 months) suffering from acute, virus-induced, hypoxemic respiratory failure. Inhaled NO was administered at a dose of 20 ppm during the first hour and subsequently decreased to a dose of 5 ppm. The effects on oxygenation were assessed by changes in arterial oxygen tension and in the oxygenation index at one and 4 hours after initiating iNO therapy. Results: Inhaled NO dramatically improved oxygenation in 3 of 4 children and reduced the oxygenation index by more than 30%. One patient showed no improvement in oxygenation, but a significant reduction in pulmonary vascular resistance. Discussion: Although previous studies have failed to show any benefit of iNO on the survival rate of children with ARDS, we believe that its use can be justified if the improvement in oxygenation helps to stabilise the patient during the acute stage of hypoxemic respiratory failure.

Zusammenfassung Fragestellung: Inhalatives Stickstoffmonoxid (iNO) wird seit einigen Jahren zur Verbesserung der Oxygenation bei Kindern und Erwachsenen mit ARDS (acute respiratory distress syndrome) eingesetzt. Wir berichten über den Soforteffekt von iNO bei 4 Kindern mit einem Virus-induzierten, hypoxämischen Atemversagen. Methode: Wir verabreichten iNO während der 1. Stunde in einer Dosis von 20 ppm und reduzierten anschließend auf 5 ppm. Die Wirkung auf die Oxygenation wurde mittels des arteriellen Sauerstoffpartialdrucks und des Oxygenationsindex beurteilt. Ergebnisse: Die Inhalation von NO führte bei 3 Kindern zu einer akuten Verbesserung der Oxygenation und zu einer Reduktion des Oxygenationsindex um mehr als 30%. Bei 1 Kind bewirkte iNO eine deutliche Abnahme des pulmonal-arteriellen Widerstands, ohne die Oxygenation zu verbessern. Diskussion: Obwohl nach bisherigen Studien die Anwendung von iNO die Mortalität des ARDS nicht senkt, halten wir dessen Einsatz bei Kindern mit akutem, hypoxämischem Atemversagen für gerechtfertigt, wenn die erzielte Verbesserung der Oxygenation zu einer Stabilisierung des Krankheitsbilds beiträgt.

Electronic Resource

1433-0458

Schlüsselwörter Tonsillektomie ; Schmerz ; Blutverlust ; Bupivacain ; Epinephrin ; Key words Tonsillectomy ; Pain ; Blood loss ; Bupivacaine ; Epinephrine

Springer Online Journal Archives 1860-2000

Medicine

Summary The effects of peritonsillar injections of epinephrine and local anesthetics before tonsillectomy on blood loss and postoperative pain were evaluated in a prospective, randomized double-blind trial on 103 children. Patients were randomly assigned into one of three groups: controls given injections of 0.9% NaCl (n=34), patients injected with 0.4 ml/kg (1:200,000) epinephrine combined with 0.25% bupivacaine (n=33) and patients given only 1:200,000 epinephrine (n=36). All injections and operations were performed by the same surgeon (KS). Blood loss was calculated by weighing all blood aspirated perioperatively and swabs used during surgery. Postoperative pain was assessed at regular intervals by using three methods: (1) use of a visual analogue scale by parents and nurses to estimate pain; (2) postoperative need for nalbuphin as analgesic; (3) the Hannallah-Broadman semi-objective pain score (including crying, anxiety, restlessness, and changes in blood pressure). The mean blood loss in the control group (given NaCl) was 132 g, which was significantly increased when compared with the epinephrine/bupivacaine group (85 g) and the group treated with only epinephrine (90 g). However, analysis of the postoperative pain scores did not reveal any significant differences among groups. These findings indicate that the peritonsillar injection of bupivacaine does not decrease postoperative pain, but peritonsillar injections of epinephrine will significantly reduce blood loss during tonsillectomy.

Zusammenfassung Anhand einer randomisierten prospektiven, doppelblinden, placebokontrollierten Studie mit 103 Kindern untersuchten wir, ob durch eine peritonsilläre Infiltration von Epinephrin und Lokalanästhetika vor Tonsillektomie der Blutverlust und die postoperativen Schmerzen vermindert werden können. Die Kinder wurden in 3 Gruppen eingeteilt: 1. NaCl-Infiltration als Kontrollgruppe, 2. Epinephrin und Bupivacain und 3. nur Epinephrin. Alle Operationen wurden durch den Erstautor ausgeführt. Der Blutverlust wurde durch Messen des Gewichts der Tupfer und des Inhalts des Absaugglases quantifiziert. Der postoperative Schmerzverlauf wurde in regelmäßigen Intervallen mittels 3 verschiedenen Methoden evaluiert: 1. Schmerzbeurteilung durch die Eltern und Kinderkrankenschwestern anhand einer “visual analogue scale”, 2. postoperativen Nalbuphin-Bedarf und 3. semiobjektiven Schmerzscore nach Hannallah und Broadman (Anaesthesiology 66:832–834, 1987). Der Median des Blutverlustes betrug in der Kontrollgruppe (NaCl) 132 g, und reduzierte sich signifikant in der Gruppe mit Epinephrin und Bupivacain auf 85 g und in der Gruppe mit nur Epinephrin auf 90 g. Die Auswertung der postoperativen Schmerzparameter zeigte keine signifikante Unterschiede zwischen den Gruppen, womit sich keine postoperative analgetische Wirkung von Bupivacain nachweisen ließ. Wir empfehlen deshalb zur Verminderung des Blutverlusts die peritonsilläre Infiltration mit 0,4 ml/kg KG Epinephrin (1:200'000), jedoch ohne Zusatz von Lokalanästhetika.

Electronic Resource

1420-9071

Dog anesthesia ; halothane ; isoflurane ; hemodynamic variables ; respiratory variables

Springer Online Journal Archives 1860-2000

Biology

Medicine

Summary In two groups of dogs, uptake and elimination of halothane and isoflurane were studied using a closed-loop anesthesia system which automatically controlled end-tidal halothane or isoflurane partial pressure at minimal alveolar concentration (MAC) equivalent levels. Hemodynamic and respiratory variables were recorded and the anesthetic partial pressure was measured in the inspired and expired air, as well as in the arterial, cerebrovenous and mixed venous blood. Data were recorded during wash-in, hyperventilation, hypercirculation, hypotension and wash-out. For halothane, the controller delivered a higher inspired partial pressure than for isoflurane to compensate for the higher blood/gas partition coefficient. This was especially pronounced during the wash-in and the hypercirculation periods. Smaller differences between halothane and isoflurane partial pressures occurred during hyperventilation, hypotension and the wash-out period and could be explained by the lower solubility of isoflurane. These results show that even under unstable ventilatory and hemodynamic conditions, the inspired concentration of isoflurane has to be adjusted less often and to a smaller degree than that of halothane if end-tidal concentrations are to be maintained constant.

Electronic Resource

1432-1076

Laryngoscopy ; Tracheal intubation ; Sympathetic reflexes ; Cerebral circulation ; Transcranial Doppler

Springer Online Journal Archives 1860-2000

Medicine

Abstract The effects of laryngoscopy and tracheal intubation on cerebral and systemic haemodynamics were studied in 30 children. The objective was to identify conditions in which the alterations of cerebral and systemic haemodynamics were minimal. The children were intubated after muscular relaxation and following 10 min of mechanical ventilation with endtidal halothane concentrations of 1.5%, 2.0% and 2.5%, respectively. With 1.5%, 2.0% and 2.5% endtidal halothane, the mean flow velocity increased by 26%, 19% and 5%, the mean blood pressure by 14%, 10% and 1%, and the heart rate by 26%, 8% and 5% respectively after intubation. Adverse effects of laryngoscopy and tracheal intubation on cerebral haemodynamics in children can be avoided by adequate anaesthetic protocols.

Electronic Resource

1432-1041

α- and β-blockade ; systolic time intervals ; oxprenolol ; phentolamine ; man

Springer Online Journal Archives 1860-2000

Chemistry and Pharmacology

Medicine

Summary The effects of single oral doses of oxprenolol (20 and 80 mg), phentolamine (20 and 40 mg), and combinations of oxprenolol and phentolamine (80:20 and 20:40 mg, respectively) on blood pressure, heart rate and the systolic time intervals (Q—S2c, PEPc, LVETc and PEP/LVET) have been studied under double-blind conditions in seven healthy volunteers during recumbency and passive tilting. Heart rate was slowed by oxprenolol and slightly increased by phentolamine, but was not affected by either of the combinations. There were only minimal non-significant changes in blood pressure in the subjects, all of whom were normotensive. Of the systolic time intervals, PEPc was most affected: it was prolonged by oxprenolol because of reduction in myocardial contractility, and shortened by phentolamine as a result of the cardiostimulant effect of this compound. When the two drugs were administered in combination, the negative inotropic effects of the β-blocker always predominated. The changes induced by the drugs were more pronounced during upright titling than in the recumbent position. Measurement of PEPc provides a suitable means of assessing the influence of cardiovascular drugs on left ventricular function in pharmacological studies in man.

Electronic Resource

1573-2614

measurement techniques: infrared ; anesthetic volatile: halothane ; equipment: gas analysis ; monitoring: end-tidal ; vapor concentration ; physics: flow characteristics ; response time

Springer Online Journal Archives 1860-2000

Computer Science

Medicine

Summary In a given inhalational anesthetic analyzer, response (RT) is usually thought to be a constant value, however, several factors may influence RT. RT's measured under ideal conditions for the Beckman LB2, the Normac (Datex), the Servo S 120 (Siemens) and the Irina (Dräger) were 107±5, 589±14, 538±30, and 166±15 msec, respectively. In addition, we investigated the RT of a Beckman LB 2 analyzer under conditions which may occur in clinical practice (non ideal conditions). Increasing aspirating flow (AF) resulted in shorter RT's, the effect being most pronounced when AF was below 200 ml/min. Interposing a filter prolonged RT by 80%. The type of the inhalational anesthetic (halothane or isoflurane), humidity and temperature of the carrier gas as well as size and direction of the concentration step change did not influence RT. Increasing lenght or internal diameter (ID) of the sample tube resulted in longer RT's. Changing the sample tube material from glass to Teflon or polyethylene resulted in a slight increase of RT, but the increase was dramatic when rubber or silicone tubes were used. The partition coefficient of halothane in the material of a particular sample tube was directly correlated to the corresponding RT in this sample tube. The influence of different sampling places was studied by interposing copper or corrugated rubber tubing between the place where the concentration step change occurred and the place where the gas was sampled, the measured time was called total response time (TRT). Using corrugated rubber tubes instead of copper tubes increased TRT two to four times. More distal gas sampling and/or lower flow rates caused longer TRT's. Compared with sampling in its center, gas sampling near the walls of the tube resulted in an increase in TRT of 13–45%. It is concluded that the response time of an infrared inhalational anesthetic analyzer is not a constant parameter, but varies between 100 and 4000 msec depending on the characteristics of the analyzer, the sample line, and the place of gas sampling.

Electronic Resource