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Clinical Effects of Pollution
Published in William J. Rea, Kalpana D. Patel, Reversibility of Chronic Disease and Hypersensitivity, Volume 5, 2017
William J. Rea, Kalpana D. Patel
Venous limb gangrene can be prevented if warfarin therapy is avoided (or reversed in a timely manner with vitamin K) in a patient with acute deep vein thrombosis in whom the presence of associated thrombocytopenia or coagulopathy indicates a potential diagnosis of cancer-associated coagulopathy or HIT.474,475 Consensus conference guidelines recommend the avoidance of warfarin during the acute (thrombocytopenic) phase of HIT.494,498 Furthermore, low-molecular-weight heparin (LMWH) is superior to warfarin in patients with cancer-associated deep vein thrombosis.499 Also, the use of inferior vena cava filters should be avoided in patients with hypercoagulable states, such as cancer or HIT, since their use can predispose the patient to venous gangrene.500
Clinical Toxicology of Iron
Published in Debasis Bagchi, Manashi Bagchi, Metal Toxicology Handbook, 2020
Shilia Jacob Kurian, Sonal Sekhar Miraj, Ahmed Alshrief, Sreedharan Nair, Mahadev Rao
Fe toxicity has five clinical stages of manifestation (see Table 18.3). The first stage can be seen with doses as less as 10 mg/kg ingestion and is associated with damage to gastrointestinal (GI) mucosa. This phase exhibits vague GI symptoms such as diarrhea, vomiting, and GI blood loss. Additionally, early signs of shock and metabolic acidosis may also be seen. A lack of symptoms within 6 hours after ingestion predicts less chance to develop any further toxic sequelae. The second stage is referred to as the “latent phase” characterized by a marked improvement in GI symptoms. However, this phase has subtle evidence of cellular toxicity and metabolic acidosis. The latent phase usually occurs within 6–24 hours, although it may not be seen in all cases. The third stage occurs within 12–48 hours and accounts for most deaths associated with the toxicity. Apart from the oxidative phosphorylation pathway and generation of free radicals, this phase accounts for metabolic and cardiovascular symptoms. This has been associated with free Fe that inhibits thrombin and its related clotting pathway resulting in coagulopathy. In addition, metabolic acidosis develops due to the recurrence of vomiting and GI bleeding, which leads to hypovolemic shock. The fourth stage (although not always present) is characterized by hepatotoxicity and is seen within 48 hours. Hepatotoxicity is generally observed at serum Fe levels >1,000 mcg/dL and rarely at levels <700 mcg/dL. The fifth stage is usually observed in 3–6 weeks after the toxic ingestion, in which patients usually present with complaints of bowel obstruction due to stricture formations (Madiwale and Liebelt 2006; Chang and Rangan 2011).
Comparison of mechanical cardiopulmonary support strategies during lung transplantation
Published in Expert Review of Medical Devices, 2020
Noah Weingarten, Dean Schraufnagel, Gilman Plitt, Anthony Zaki, Kamal S. Ayyat, Haytham Elgharably
CPB’s disadvantages relate to inflammation and coagulopathy. CPB induces a systemic inflammatory response when blood interacts with the circuit’s nonendothelial surface thereby activating the coagulation cascade. This activation in turn leads to the elaboration of a broad set of inflammatory mediators [27–29]. Leukocyte-depleting filters have been added to CPB circuits to decrease systemic inflammation, but their clinical benefit has not been definitively proven [30]. CPB induces coagulopathy by subjecting blood to non-laminar flow in an oxygenator, causing blood stasis in its venous reservoir, hemodiluting clotting factors via the infusion of priming fluids, and inducing fibrinolysis and platelet consumption [31–34]. To prevent life-threatening clotting, CPB requires high dose heparinization protocols that aim to maintain activated clotting times greater than 400 seconds [35]. Protamine, which is used to reverse heparin, has been linked to a paradoxical anticoagulant effect at excessive doses, as well as anaphylaxis, pulmonary edema, and pulmonary hypertension [34,36]. Following successful reversal of heparin with protamine, patients may be subject to a heparin rebound effect that increases risk of postoperative bleeding [34,36]. Whether prolonged time on CPB exacerbates these risks during LT is unknown, though evidence suggests that prolonged time on CPB is associated with various worse clinical outcomes in patients undergoing other surgeries like coronary artery bypass grafting [37].
Chronic iliofemoral vein obstruction – an under-recognized cause of exercise limitation‡
Published in European Journal of Sport Science, 2018
Michael J. Segel, Ronen Reuveny, Jacob Luboshitz, Dekel Shlomi, Issahar Ben-Dov
A cohort of nine adults (five females, four males) with persistent IFVO after DVT (eight unilateral, one bilateral) was identified from the National Haemophilia & Coagulopathy Center in Sheba Medical Center. DVT and subsequent persistent IFVO were diagnosed by Doppler ultrasonography. A reference cohort (n = 11, 5 females, 6 males) consisted of healthy adults with no pertinent medical history. The study (IFVO) and reference cohorts were not matched. A post hoc sample size calculation was performed assuming a mean arm: leg peak ⩒O2 ratio of 0.7 in controls and 1.0 in IFVO patients, with a standard deviation of 0.2. The calculation was for a one-sided test of significance, with 80% power and an alpha of 0.05, and yielded a sample size of 7 per group. Thus our study of 11 healthy subjects and 9 IFVO patients is adequately powered. The study was approved by the Institutional Ethics Committee for Human Medical Research (Sheba Medical Center 9668-12-SMC). Written informed consent was obtained from all subjects.