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Risk stratification is an essential part of appropriately informing patients electing to undergo percutaneous coronary intervention or coronary artery bypass graft surgery. In addition, there is a greater need than ever to tailor revascularization appropriately, taking into consideration a patient's co-morbidities, coronary anatomy, personal preferences, and individual perception of risk. This chapter examines the important established and evolving contemporary clinical tools used to aid the Heart Team in this risk-stratification process. Risk scores based on clinical and anatomical variables alone and in combination are all explored. Other areas of discussion include risk scores based upon completeness of revascularization and decision-making between surgical and percutaneous-based revascularization in complex coronary artery disease.
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ABSTRACT A test program on concrete‐filled double skin tubular (CFDST) beams with austenitic stainless steel outer tubes and high strength steel inner tubes is presented in this paper. A total of 22 four‐point bending tests was carried out to study the behaviour and strengths of CFDST beams. The stainless steel outer tubes were circular hollow sections (CHS) with average diameter‐to‐thickness ratios of 56.8 and 48.5, and the measured 0.2% proof strengths of 276 MPa and 300 MPa, respectively. The high strength steel inner tubes were also circular hollow sections (CHS) with diameter‐to‐thickness ratios ranging from 5.0 to 22.8, and corresponding measured 0.2% proof stress ranging from 433 to 1029 MPa. The annuli were filled with concrete with three different concrete cylinder strengths of 40, 80 and 120 MPa. The moment capacities, moment–curvature relationships and failure modes of the beams are reported in this paper. It should be noted that currently there are no design provisions for concrete‐filled stainless steel members. The test strengths were therefore compared with the moment capacity predictions in existing design codes (the European Code and American Specification) for concrete‐filled carbon steel tubes. The comparisons revealed that both design codes provide very conservative resistance predictions.
From this brief overview the arguments have become clear why further studies are needed to verify that the problem of unnecessary sudden cardiac death can best be tackled by a strategy aimed at early and complete revascularization. Whether such a strategy begins with intravenous injection of rt-PA at home or requires subsequent intracoronary manipulation when obstruction persists, whether by thrombolysis with other agents, PTCA or bypass surgery, is in itself a moot point. The main aim should be to offer this strategy as the best chance to reduce the unnecessary sudden death rate which presently accounts for between 25 and 50% of all cardiac deaths. This approach deserves consideration particularly since earlier approaches employing cardioprotective efforts by beta blockade or by anti arrhythmic agents have patently shown that they cannot tackle the problem in a convincing manner.
Leukotriene B 4 (LTB 4 ) stimulation of guinea‐pig peritoneal eosinophils, induced a biphasic activation of the NADPH oxidase composed of a rapid (<3 min) phase mediated by non‐adherent cells and a sustained (3 – 120 min) phase mediated by CD11b/CD18 adherent eosinophils. Studies were undertaken to compare the intracellular mechanism that mediate these responses. SB 203580 and PP1, inhibitors of p38 mitogen‐activated protein (MAP) kinase and the src‐family protein tyrosine kinases, respectively caused concentration‐dependent attenuation of both the rapid (SB203580: pD 2 =−6.31; PP1: pD 2 =−5.50) and sustained (SB203580: pD 2 =−6.50; PP1: pD 2 =−5.73) phases. Similarly, the MAP kinase kinase‐1 inhibitor, PD098059 produced partial inhibition of the both phases of superoxide generation. The protein kinase C (PKC) inhibitors Ro‐31 8220, GF 109203X and Gö 6976 attenuated the rapid NADPH oxidase response (pD 2 s=−6.10, −6.72, −6.15 respectively) and, to a lesser extent, (pD 2 s=−5.54, −6.02, −6.51 respectively) the sustained phase. An inhibitor of phosphatidylinositol 3‐kinase (PtdIns 3‐kinase), wortmannin caused concentration dependent attenuation of the sustained (pD 2 =−8.68) but not rapid phase of superoxide generation. In contrast, the syk kinase inhibitor, piceatannol abolished the rapid (pD 2 =−6.43) but not sustained respiratory responses. This study demonstrates that LTB 4 ‐induced superoxide generation from adherent and non‐adherent eosinophils is mediated via both common (p38 MAP kinase, MEK‐1, PKC and the src kinases) and divergent intracellular pathways (syk kinases and PtdIns 3‐kinase). This suggests the possibility of therapeutic intervention to selective attenuate activation of adherent tissue eosinophils. British Journal of Pharmacology (2001) 134 , 797–806; doi: 10.1038/sj.bjp.0704314
Acute severe asthma in adults Recognition and assessment in hospital Features of acute severe asthma * Can't complete sentences in one breath * Respirations 225 breaths/min * Pulse 11O beats/min * Peak expiratory flow (PEF) s 50% of predicted * or best Life threatening features * PEF <33% of predicted or best * Silent chest, cyanosis, or feeble respiratory effort * Bradycardia or hypotension * Exhaustion, confusion, or coma If a patient has any of these features, then measure arterial blood gases.Markers of a very severe, life threatening attack: * Normal (5-6 kPa, 36-45 mm Hg) or high Faco2 * Severe hypoxia: Pao2 <8 kPa (60 mm Hg) irrespective of treatment with oxygen * A low pH (or high H+) No other investigations are needed for immediate management.
