Prinzipien des perioperativen Gerinnungsmanagements

Zusammenfassung: Das Gerinnungssystem ist ein komplexes Netzwerk aus interagierenden Proteinen und Zellen. Reguliert und kontrolliert wird dieses System durch positive und negative Feedback-Schleifen. Eine normale Blutgerinnung ist dann vorhanden, wenn gerinnungsfördernde und -hemmende Kräfte im Gleichgewicht stehen. Klinisch relevante Phänotypen der Hämostase, d.h. Blutungen und Thrombosen entstehen, wenn dieses Gleichgewicht gestört wird. Für die optimale Behandlung einer perioperativ auftretenden Gerinnungsstörung ist ein solides Grundverständnis der Hämostase erforderlich. Bei einer Blutung erlauben Anamnese und klinische Präsentation, Laboranalysen und bettseitige Gerinnungsanalysen schnell eine spezifische Diagnose der entsprechenden Gerinnungsstörung. Ein modernes Gerinnungsmanagement, das proaktiv, individuell und balanciert durchgeführt werden soll, orientiert sich an definierten Algorithmen. Eine durch eine Gerinnungsstörung verursachte Blutung kann dadurch erfolgreich behandelt werde

Patient well-being after general anaesthesia: a prospective, randomized, controlled multi-centre trial comparing intravenous and inhalation anaesthesia

Background. The aim of this study was to assess postoperative patient well‐being after total i.v. anaesthesia compared with inhalation anaesthesia by means of validated psychometric tests. Methods. With ethics committee approval, 305 patients undergoing minor elective gynaecologic or orthopaedic interventions were assigned randomly to total i.v. anaesthesia using propofol or inhalation anaesthesia using sevoflurane. The primary outcome measurement was the actual mental state 90 min and 24 h after anaesthesia assessed by a blinded observer using the Adjective Mood Scale (AMS) and the State‐Trait‐Anxiety Inventory (STAI). Incidence of postoperative nausea and vomiting (PONV) and postoperative pain level were determined by Visual Analogue Scale (VAS) 90 min and 24 h after anaesthesia (secondary outcome measurements). Patient satisfaction was evaluated using a VAS 24 h after anaesthesia. Results. The AMS and STAI scores were significantly better 90 min after total i.v. anaesthesia compared with inhalation anaesthesia (P=0.02, P=0.05, respectively), but equal 24 h after both anaesthetic techniques (P=0.90, P=0.78, respectively); patient satisfaction was comparable (P=0.26). Postoperative pain was comparable in both groups 90 min and 24 h after anaesthesia (P=0.11, P=0.12, respectively). The incidence of postoperative nausea was reduced after total i.v. compared with inhalation anaesthesia at 90 min (7 vs 35%, P<0.001), and 24 h (33 vs 52%, P=0.001). Conclusion. Total i.v. anaesthesia improves early postoperative patient well‐being and reduces the incidence of PONV. Br J Anaesth 2003; 91: 631-

New insights into the genetic etiology of Alzheimer's disease and related dementias

Characterization of the genetic landscape of Alzheimer's disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/'proxy' AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE ε4 allele

How reliable is length-based determination of body weight and tracheal tube size in the paediatric age group? The Broselow tape reconsidered

Background. The Broselow tape was designed to estimate body weight and tracheal tube size on the basis of the body length of emergency paediatric patients. The tape was validated previously in US populations. We assessed its accuracy in a sample of European children by reviewing paediatric anaesthetic charts at the Triemli City Hospital for 1999. Methods. Age, body length and body weight measured before surgery as well as the size of the tracheal tube used were recorded. The body weight was estimated on the basis of body length using the Broselow tape and was compared with the measured weight. Tracheal tube size selections using the Broselow tape and an age‐based formula were compared with the size of the tube used. Results. A good correlation was found between the Broselow weight and the measured weight (r2=0.88). Bland-Altman analysis revealed a mean bias of -0.52kg for the entire study population. For children ≤20kg the mean bias was -0.05kg, and for children >20kg was -1.05kg. The Broselow weight was found to be within a 10% error of the measured weight in 65% of children. Tracheal tube selection by the Broselow tape method was adequate in 55% but underestimated the actual tube size in 39%. The age‐based formula matched the actual tracheal tube size in 41% of children but overestimated it in 57%. Conclusions. The Broselow tape is an accurate means to assess body weight from length in smaller children; in older children it underestimated body weight. Endotracheal tube size selection by the Broselow tape appears to match the size of the tube used better than the age‐based formula. The results in a European sample of children are comparable to the US data. Br J Anaesth 2002; 88: 283-

Illumination of x-rays: the usual lights exposed

Aims: Faced with pressure of work and limited resource, doctors frequently use the nearest available light to examine x-ray films. The aim of this study was to examine the relative intensities of hospital light sources, and to compare these with the light intensity guidelines (1500 to 3000 candelas) of the British Institute of Radiology. Methods: The relative intensities of seven hospital light sources were examined using a standard light meter at a constant 30 cm from the source. A control group of 10 individual consultant's x-ray viewing boxes were compared with six other ward based light sources. Results: Only two light sources approached the British Institute of Radiology light intensity x-ray viewing criteria: the x-ray viewing boxes of consultant radiologists with a median light intensity of 3503 candelas (χ(2)=13.3, df 1; p=0.0001), and daylight from north facing windows with a median of 1464 candelas when overcast (χ(2)=8.571, df 1; p=0.003) and 4669 candelas in sunshine (χ(2)= 6.364, df 1; p=0.0001). Conclusion: Few hospital light sources met the British Institute of Radiology guidelines. The long held high regard of artists for northern light appears justified even in the environment of a British district general hospital