Preservation of All Chordae Tendineae and Papillary Muscle During Mitral Valve Replacement with a Tilting Disc Valve

Mitral valve replacement was performed in 21 patients using a surgical technique that preserves the entire papillary muscle and chordal apparatus. With this technique, the anterior mitral leaflet is split from the center of the free edge toward the annulus. Bilateral incisions are made from the proximal end of this split to the two mitral commissures, detaching the anterior leaflet from the annulus. These two halves of the leaflet, with all chordae intact (corresponding to the anterolateral and posteromedial papillary muscles), are judiciously trimmed to remove areas of leaflet untethered by chordae tendineae and (when necessary) fibrous thickening; then swung posteriorly and sutured to the posterior mitral annulus using mattress sutures with pledgets. This surgical technique is expected to favor the preservation of left ventricular function and avoid occurrence of irreversible left ventricular dilation/dysfunction, and has been used successfully for calcific and degenerative etiologies, using both tilting disc valves and porcine bioprostheses. It is especially useful in the implantation of tilting disc and bileaflet mechanical prostheses because anterior subvalvular chordae tissue may interfere with the disc excursion and relocated to the posterior leaflet annulus.     

Automatic jet ventilation in children anaesthetized by the T-piece circuit

Investigation was carried out in ten children aged between one month and six years, who were anaesthetized by the T-piece circuit. The volume of the reservoir tubing of the T-piece was 250 ml. Ventilation was controlled automatically by oxygen jets which were delivered via an injector attached to the reservoir tubing. The oxygen jets were regulated by an electronically-controlled solenoid valve. The children were ventilated by a tidal volume about 12 ml±kg^?1 at a rate of 12-20 per min depending on their age, while the FGF varied between 3 and 6 l min^?1 depending on their body weight. The resulting FIO₂ ranged between 0.32 and 0.34 which was expected from the oxygen:nitrous oxide mixture (1:2), denoting no mixing of the oxygen jets with the anaesthetic mixture. The PA_co2 was ventilation-dependent, and ranged between 4±6-5±3 kPa (35-41 mmHg). The results suggest that automatic jet ventilation facilitates controlled ventilation in children anaesthetized by the T-piece circuit, while maintaining the original simplicity of the T-piece.;     

A monoclonal antibody directed against a granule membrane glycoprotein (GMP-140/PADGEM, P-selectin, CD62P) inhibits ristocetin-induced platelet aggregation

P-selectin (also called CD62, GMP-140, PADGEM, CD62P) is a recently described member of a family of vascular adhesion receptors expressed by activated platelets and endothelial cells that are involved in leucocyte cell adhesion. The aim of this study was to characterize a new monoclonal antibody (LYP7) directed against activated human blood platelets that inhibits ristocetin-induced platelet aggregation. Immunoadsorbent affinity chromatography and immunoprecipitation studies showed that LYP7 (IgG₁) bound a surface-labelled glycoprotein (GP) which changed its apparent molecular mass (M_r) on reduction from 138 kD (situated below GPIIb) to 148 kD (above GPIIbα). LYP7 and S12, a monoclonal antibody directed against P-selectin immunoprecipitated the same band. Using ELISA assay, purified P-selectin was shown to bind LYP7 and S12 monoclonal antibodies. Binding sites of ¹²⁵I-labelled LYP7, which was greatly increased on thrombin-stimulated (2 U/ml) washed platelets (10825±2886, mean ±SD) (K_d=1.5±0.5 nm ) compared to resting platelets (2801±1278, mean ±SD) (K_d=1.5±0.6 nm ), was found to be normal on thrombin-stimulated platelets taken from a patient with grey platelet syndrome or a patient with Glanzmann thrombasthenia. LYP7 (IgG₁, F(ab′)₂ or Fab fragments) inhibited ristocetin-induced platelet aggregation of platelets in a dose-dependent fashion without affecting the binding of von Willebrand (vWf ) factor. However, agglutination of formaldehyde-fixed platelets induced by ristocetin was not affected by monoclonal antibody LYP7. In addition, the binding of thrombin-activated platelets to neutrophils was inhibited by monoclonal antibody LYP7. These results strongly suggest that P-selectin, by promoting cell–cell contact, may play an active role in platelet–platelet interactions.     

The measurement of psychotic acuity by nursing staff

Accurate evaluation of patients' psychotic state is essential to decrease psychotic symptoms and protect the patient and others. The aim of this paper is to conduct a literature review in order to access the utility, reliability and validity of current rating scales that are purported to measure psychotic acuity of inpatient population. A search of a number of electronic databases was undertaken to retrieve potential articles that focus on the measurement of acute psychosis. We identified some conceptual and theoretical problems when using a scale that is monitoring the progress of discharge and assesses the outcome of treatments. The findings revealed a difficulty in finding a commonly agreed definition of acute psychosis and a problem of obtaining frequent measures, and the frequency of measurement and fluctuation in psychosis. The most dominant scales in assessing psychosis were reviewed: the Global Assessment of Functioning Scale, the Brief Psychiatric Rating Scale and the Positive and Negative Symptom Scale. Several issues related to the scales' inter-rater reliability and construct validity remain unexplored. None of these scales addressed the conceptual and theoretical problems that we identified. A new scale that will measure acuity of symptoms in inpatient settings needs to be created.     

The mediating effect of burnout on the relationship between structural empowerment and organizational citizenship behaviours

gilbert s. , laschinger h.k.s. & leiter m (2010) Journal of Nursing Management 18, 339–348
The mediating effect of burnout on the relationship between structural empowerment and organizational citizenship behaviours Aim We used Kanter’s (1977) structural empowerment theory to examine the influence of structural empowerment and emotional exhaustion on healthcare professionals’ use of organizational citizenship behaviours directed at the organization (OCBO) and peers (OCBI). Background Organizational citizenship behaviours (OCB) are discretionary behaviours that are not rewarded directly by the organization but have been linked to positive outcomes, such as increased job satisfaction and lower turnover intentions. Promoting OCB can help employees and organizations flourish despite current challenges in the healthcare system. Structural empowerment may influence the frequency and type of OCB by reducing burnout. Method We conducted multiple mediated regression analyses to test two hypothesized models about relationships between empowerment, emotional exhaustion and two types of OCB (OCBI and OCBO) in a sample of 897 healthcare professionals in five Canadian hospitals. Results Emotional exhaustion was found to be a significant mediator of the relationship between empowerment and OCBO. The predicted mediation of the empowerment/OCBI relationship by emotional exhaustion was not supported. Conclusions Exhaustion was an important mediator of empowering working conditions and OCBO, but was not significantly related to OCBI. Empowerment was significantly related to both OCBO and OCBI. Implications for nursing management Promoting empowerment among healthcare workers may decrease burnout and promote OCB. Specific managerial strategies are discussed in the present study.