Platelet Functions in Cardiopulmonary Bypass Surgery

Background

Haemorrhage after Cardio Pulmonary Bypass (CPB) Surgery is a well recognised complication that leads to significant morbidity and mortality. The incidence varies between 5-25% depending upon the clinical situation. Several factors are implicated as causative but none have been precisely proved.

Methods

Our study was an attempt to evaluate the haemostatic defect with particular reference to platelet function abnormalities during cardio pulmonary bypass surgery, in order to reduce the morbidity and mortality associated with post CPB haemorrhage. Flow cytometric evaluation of different platelet glycoproteins like GPIb/IX, GPIIb/IIIa and GMP-140 was done.

Results

The marker expression showed deregulation during surgery which returned to base after bypass was terminated. In contrast, the cases with bleeding showed significant variation. P-Selectin (GMP 140) expression decreased progressively till 3^rd post-operative day showing lack of activation of platelets in cases of severe bleeding.

Conclusion

Longer duration of CPB initiates plasmin generation through heparin, which raises the PAI-1-tPA complex and thereby down regulating the functions of platelets. This suggests a link between duration of CPB, bleeding, platelet dysfunction and fibrinolysis. Hence serial estimations of the levels of GMP-140 and tPA can predict severe bleeding.Key Words: CardioPulmonary Bypass, Platelet dysfunction, flowcytometry, platelet glycoproteins, haemorrhage     

Inpatient medical rehabilitation in diabetes mellitus in light of evidence based practice guidelines: an evaluation on the basis of BfA routine data

OBJECTIVE: Multidisciplinary team care is an opportunity to improve the long-term metabolic situation of patients with diabetes mellitus, hence can help reduce the individual and financial burden of diabetes-related complications. The aim of this study is to evaluate the extent to which patients undergoing rehabilitation carried by the German Federal Insurance Institute for Salaried Employees (BfA) were treated in accordance with recent evidence-based clinical practice guidelines on diabetes mellitus. METHODS: We extracted specific treatment recommendations relevant to inpatient rehabilitation from national and international evidence-based guidelines and allocated them to general subjects of diabetes care (e. g. [disease specific] education, physical activity, psychosocial interventions). In the "Classification of Therapeutic Procedures (KTL)", an instrument used to classify therapeutic procedures in rehabilitation, we then identified those procedures that represented the recommendations of the guidelines. The coded procedures were allocated to the general aspects of diabetes care, too. In total, 9 "therapeutic modules" were designed, each containing guideline-recommendations and coded procedures. Using the KTL codes documented as a routine in discharge reports, we were able to describe, analyse and evaluate the procedures performed during rehabilitation. The data set we used contained KTL codes and medical information from 9,456 patients whose rehabilitation was carried by the BfA diagnosed with either diabetes mellitus type 1 or 2, who received an inpatient rehabilitation procedure during the years 2000 and 2001. RESULTS: The number of patients who received at least one procedure out of the particular therapeutic module is as follows (numbers in brackets represent the total number of KTL codes in that therapeutic module): Therapeutic module "Education (3)" - 98.66 %, "Exercise Training (63)" - 92.42 %, "Nutrition Training (14)" - 96.44 %, "Stress (18)" - 35.33 %, "Motivation (15)" - 82.87 %, "Coping Skills (15)" - 27.42 %, "Social Work (26)" - 11.44 %, "Alcohol and Nicotine (24)" - 3.69 %, "Diabetic Complications (81)" - 75.42 %. On average patients received procedures out of 5.2 different therapeutic modules. The results were consistent over subgroups (type 1/type 2 diabetes, men/women) but varied considerably between clinics. The care provided in clinics with higher numbers of diabetic patients is more in line with guideline specifications. DISCUSSION: A substantial number of patients received procedures out of the therapeutic modules "Education", "Exercise Training", "Nutrition Training" and "Motivation". In other therapeutic modules (e. g. "Alcohol and Nicotine") deficits were noted. These deficits as well as the substantial variation between clinics demonstrate the need to develop clinical practice guidelines for rehabilitation of patients with diabetes. In principle, the results of this study have to be interpreted carefully because we did not examine to which extent the documented processes are in accordance with the realities. CONCLUSIONS: Inpatient rehabilitation of diabetic patients carried by the BfA can be characterised as multidisciplinary and in accordance with the recommendations of recent evidence-based guidelines. Certain problematic aspects should be put into focus. A guideline taking into account all rehabilitative aspects, including the preparation for and the care after the rehabilitation process, can be instrumental in reducing deficits in rehabilitative care as well as differences between clinics. To gain wide acceptance, guideline development should be coordinated by a scientific institute and involve members of all groups concerned (e. g. the rehabilitative team, GPs, patients). Within certain limits the "KTL" instrument permits evaluation of process quality in rehabilitation of patients with diabetes mellitus.     

Ultrasound‐guided percutaneous tenotomy for the treatment of iliopsoas impingement: A description of technique and case study

Iliopsoas impingement is a commonly recognised source of groin pain following total hip replacement. When conservative measures fail, open or arthroscopic iliopsoas tendon release can reliably alleviate pain and improve function. This article describes an alternative ultrasound‐guided percutaneous technique, achieving iliopsoas tenotomy utilising a modified 18G coaxial needle and thus minimising the morbidity and cost associated with an open or arthroscopic procedure. This method proved successful with resultant complete resolution of patient symptoms. To the knowledge of the authors, this is the first case of ultrasound‐guided percutaneous iliopsoas tenotomy for iliopsoas impingement post total hip replacement.     

Distribution of mutations in the PEX gene in families with X-linked hypophosphataemic rickets (HYP)

Mutations in the PEX gene at Xp22.1 (phosphate-regulating gene with homologies to endopeptidases, on the X-chromosome), are responsible for X-linked hypophosphataemic rickets (HYP). Homology of PEX to the M13 family of Zn2+ metallopeptidases which include neprilysin (NEP) as prototype, has raised important questions regarding PEX function at the molecular level. The aim of this study was to analyse 99 HYP families for PEX gene mutations, and to correlate predicted changes in the protein structure with Zn2+ metallopeptidase gene function. Primers flanking 22 characterised exons were used to amplify DNA by PCR, and SSCP was then used to screen for mutations. Deletions, insertions, nonsense mutations, stop codons and splice mutations occurred in 83% of families screened for in all 22 exons, and 51% of a separate set of families screened in 17 PEX gene exons. Missense mutations in four regions of the gene were informative regarding function, with one mutation in the Zn2+-binding site predicted to alter substrate enzyme interaction and catalysis. Computer analysis of the remaining mutations predicted changes in secondary structure, N-glycosylation, protein phosphorylation and catalytic site molecular structure. The wide range of mutations that align with regions required for protease activity in NEP suggests that PEX also functions as a protease, and may act by processing factor(s) involved in bone mineral metabolism.