The role of pulmonary arterial stiffness in COPD

AbstractCOPD is the second most common cause of pulmonary hypertension, and is a common complication of severe COPD with significant implications for both quality of life and mortality. However, the use of a rigid diagnostic threshold of a mean pulmonary arterial pressure (mPAP) of ≥25mHg when considering the impact of the pulmonary vasculature on symptoms and disease is misleading. Even minimal exertion causes oxygen desaturation and elevations in mPAP, with right ventricular hypertrophy and dilatation present in patients with mild to moderate COPD with pressures below the threshold for diagnosis of pulmonary hypertension. This has significant implications, with right ventricular dysfunction associated with poorer exercise capability and increased mortality independent of pulmonary function tests.The compliance of the pulmonary artery (PA) is a key component in decoupling the right ventricle from the pulmonary bed, allowing the right ventricle to work at maximum efficiency and protecting the microcirculation from large pressure gradients. PA stiffness increases with the severity of COPD, and correlates well with the presence of exercise induced pulmonary hypertension. A curvilinear relationship exists between PA distensibility and mPAP and pulmonary vascular resistance (PVR) with marked loss of distensibility before a rapid rise in mPAP and PVR occurs with resultant right ventricular failure. This combination of features suggests PA stiffness as a promising biomarker for early detection of pulmonary vascular disease, and to play a role in right ventricular failure in COPD. Early detection would open this up as a potential therapeutic target before end stage arterial remodelling occurs

Clinical evaluation of a new ultrasonic Doppler instrument (SonoDoppler) for the detection of blood flow during laparoscopic procedures.

Complications may be avoided by exactly clarifying the structures in the operative field during laparoscopic surgery. We aimed to study the efficiency of a new ultrasonic Doppler device, SonoDoppler, which offers an easy and efficient way of mapping the anatomy. The design of the study was prospective, open observational and carried out on a sample of 51 patients who were operated on in four hospitals. The surgeons were asked to identify a common hepatic artery, cystic artery and portal vein during a laparoscopic cholecystectomy, and corresponding structures during other laparoscopic procedures using the SonoDoppler, instrument. Total operation time (skin-to-skin) and duration of the SonoDoppler, use were measured. The main outcome measures were gain of additional safety and clinical value. A number of evaluations concerning the ergonomics, functionality and interactions with other instruments were also carried out. The SonoDoppler, instrument has the potential to help to assess and clarify the anatomy during laparoscopic procedures. Its use can be advocated not only for inexperienced surgeons, to help them map the vessels during surgery, but also for experienced surgeons during complicated cases and advanced procedures