All available evidence today indicates that chronic thromboembolic pulmonary hypertension (CTEPH) is primarily caused by venous thromboembolism (VTE), as opposed to primary pulmonary vascular in situ thrombosis. Both the initial magnitude of clot and PE recurrences may contribute to the development of CTEPH. Only few specific thrombophilic factors such as phospholipid antibodies, lupus anticoagulant, and elevated factor VIII are statistically associated with CTEPH.

A mechanistic view of CTEPH as a disease caused by obliteration of central pulmonary arteries by pulmonary emboli is too simplistic. Based on available data one may speculate that pulmonary embolism may be followed by a pulmonary vascular remodeling process modified by infection, immune phenomena, inflammation, circulating and vascular-resident progenitor cells thyroid hormone replacement or malignancy.

Both plasmatic factors (hypercoagulation, "sticky" red blood cells, high platelet counts, uncleavable fibrinogens) and a misguided vascular remodelling process contribute to major vessel and small vessel obliteration. Endothelial dysfunction and endothelial-mesenchymal transition may be important, but their precise roles remain obscure. There exists no animal model for CTEPH, therefore, experimentation in the future must include human tissues and clinical data in parallel.

Isolated distal deep-vein thromboses (DVT) are infra-popliteal DVT without involvement of proximal veins or pulmonary embolism (PE). They can affect deep calf (tibial anterior, tibial posterior, or peroneal) or muscular (gastrocnemius or soleal) veins. They represent half of all lower limbs DVT.

Proximal and distal DVTs differ in terms of risk factor profile, proximal DVT being more frequently associated with chronic risk factors and distal DVT with transient ones. Their natural history (rate of spontaneous proximal extension) is debated leading to uncertainties on the need to diagnose and treat them with anticoagulant drugs.

In the long term, the risk of venous thromboembolic recurrence is lower than that of proximal DVT and their absolute risk of post-thrombotic syndrome is unknown. French national guidelines suggest treating with anticoagulants for 6 weeks a first episode of isolated distal DVT provoked by a transient risk factor and treating for at least 3 months unprovoked or recurrent or active cancer-related distal DVT.

The use of compression stockings use is suggested in case of deep calf vein thrombosis. Ongoing therapeutic trials should provide important data necessary to establish an evidence-based mode of care, especially about the need to treat distal DVT at low risk of extension with anticoagulants.

The effects of respiratory training for chronic obstructive pulmonary disease patients: a randomised clinical trial.

J Clin Nurs. 2012 Jun 2;

Authors: Lin WC, Yuan SC, Chien JY, Weng SC, Chou MC, Kuo HW

Abstract
Aims and objectives.  To assess the effects of respiratory training on lung function, activity tolerance and quality of life in patients with chronic obstructive pulmonary disease. Background.  For patients with chronic obstructive pulmonary disease, pulmonary rehabilitation can increase activity tolerance and improve their psychological state by relieving dyspnoea and promoting their quality of life. Design.  A randomised clinical trial was conducted in a local hospital. Methods.  Patients with chronic obstructive pulmonary disease were randomly assigned to intervention (n = 20) and control groups (n = 20). Spirometry, six-minute walking distance and quality of life were used to assess the efficacy of respiratory training programme. Results.  Significant improvement in lung function, including forced vital capacity (p = 0·037), forced expiratory volume in one-second (p = 0·006) and per cent predicted forced expiratory volume in one-second (p = 0·008) in the intervention group. Regarding efficacy of the training programme for patients with chronic obstructive pulmonary disease, in forced expiratory volume in one-second (p = 0·024) and per cent predicted forced expiratory volume in one-second (p = 0·035), six-minute walking distance significantly increased. In addition, there were significant improvements for symptoms (p = 0·018), impact (p < 0·001) and total quality of life scores (p < 0·001), as well as significantly decreased body mass, airflow obstruction, dyspnoea and exercise capacity index (p = 0·004) in the intervention group. Conclusions.  A respiratory training programme for patients with chronic obstructive pulmonary disease was found to relieve dyspnoea, maintain lung function, increase activity tolerance and improve quality of life. Relevance to clinical practice.  Respiratory training programme can be used as a routine rehabilitation protocol for patients with chronic obstructive pulmonary disease and can be used by nurses as a reference to monitor chronic obstructive pulmonary disease patients' health status.

PMID: 22672732 [PubMed - as supplied by publisher]

While prognostically valuable, physical activity monitoring is not routinely performed for patients with COPD. We aimed to determine the number of daily steps associated with severe physical inactivity (physical activity level <1.40) in this population.

We found that a daily step value <4,580 is associated with severe physical inactivity. © 2012 The Authors. Respirology © 2012 Asian Pacific Society of Respirology.