Malignant hyperthermia in North America: genetic screening of the three hot spots in the type I ryanodine receptor gene

BACKGROUND: Malignant hyperthermia (MH) is a pharmacogenetic disorder of skeletal muscle, manifested as a life-threatening hypermetabolic crisis after exposure to anesthetics. Type I ryanodine receptor 1 is the primary gene responsible for susceptibility to MH as well as central core disease, a congenital myopathy that predisposes susceptibility to MH. More than 40 mutations in the RyR1 gene cluster in three coding regions: the N-terminus, central, and C-terminus regions. However, the frequency of mutations in each region has not been studied in the North American MH-susceptible population. METHODS: The authors tested 124 unrelated patients with MH susceptibility for the presence of mutations in the N-terminus (exons 2, 6, 9, 11, 12, and 17), central (exons 39, 40, 44, 45, and 46), and C-terminus (exons 95, 100, 101, and 102) regions. RESULTS: Fourteen mutations have been identified in 29 of 124 MH-susceptible patients (23%). Approximately 70% of the mutations, which include a novel mutation, Ala 2437Val, were in the central region. In 8 patients (28%), mutations were identified in the N-terminus region. Screening the C-terminus region yielded a novel mutation, Leu4824Pro, in a single patient with a diagnosis of central core disease. CONCLUSIONS: The detection rate for mutations is only 23% by screening mutations (or exons) listed in the 2002 North American consensus panel. The implications from this study suggest that testing the central region first is currently the most effective screening strategy for the North American population. Screening more exons in the three hot spots may be needed to find an accurate frequency of mutations in the RyR1 gene.     

Enoxaparin vs unfractionated heparin in high-risk patients with non-ST-segment elevation acute coronary syndromes managed with an intended early invasive strategy: primary results of the SYNERGY randomized trial

Context  Enoxaparin has demonstrated advantages over unfractionated heparin in low- to moderate-risk patients with non–ST-segment elevation acute coronary syndromes (ACS) treated with a conservative strategy. Objectives  To compare the outcomes of patients treated with enoxaparin vs unfractionated heparin and to define the role of enoxaparin in patients with non–ST-segment elevation ACS at high risk for ischemic cardiac complications managed with an early invasive approach. Design, Setting, and Participants  The Superior Yield of the New Strategy of Enoxaparin, Revascularization and Glycoprotein IIb/IIIa Inhibitors (SYNERGY) trial was a prospective, randomized, open-label, multicenter, international trial conducted between August 2001 and December 2003. A total of 10 027 high-risk patients with non–ST-segment elevation ACS to be treated with an intended early invasive strategy were recruited. Interventions  Subcutaneous enoxaparin (n = 4993) or intravenous unfractionated heparin (n = 4985) was to be administered immediately after enrollment and continued until the patient required no further anticoagulation, as judged by the treating physician. Main Outcome Measures  The primary efficacy outcome was the composite clinical end point of all-cause death or nonfatal myocardial infarction during the first 30 days after randomization. The primary safety outcome was major bleeding or stroke. Results  The primary end point occurred in 14.0% (696/4993) of patients assigned to enoxaparin and 14.5% (722/4985) of patients assigned to unfractionated heparin (odds ratio [OR], 0.96; 95% confidence interval [CI], 0.86-1.06). No differences in ischemic events during percutaneous coronary intervention (PCI) were observed between enoxaparin and unfractionated heparin groups, respectively, including similar rates of abrupt closure (31/2321 [1.3%] vs 40/2364 [1.7%]), threatened abrupt closure (25/2321 [1.1%] vs 24/2363 [1.0%]), unsuccessful PCI (81/2281 [3.6%] vs 79/2328 [3.4%]), or emergency coronary artery bypass graft surgery (6/2323 [0.3%] vs 8/2363 [0.3%]). More bleeding was observed with enoxaparin, with a statistically significant increase in TIMI (Thrombolysis in Myocardial Infarction) major bleeding (9.1% vs 7.6%, P = .008) but nonsignificant excess in GUSTO (Global Utilization of Streptokinase and t-PA for Occluded Arteries) severe bleeding (2.7% vs 2.2%, P = .08) and transfusions (17.0% vs 16.0%, P = .16). Conclusions  Enoxaparin was not superior to unfractionated heparin but was noninferior for the treatment of high-risk patients with non–ST-segment elevation ACS. Enoxaparin is a safe and effective alternative to unfractionated heparin and the advantages of convenience should be balanced with the modest excess of major bleeding.      

Can cardiac troponins be used to diagnose a perioperative myocardial infarction post cardiac surgery?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was whether Troponin I or T can effectively diagnose a perioperative myocardial infarction after cardiac surgery. Altogether 191 papers were found using the reported search, of which 17 presented the best evidence to answer the clinical question. The author, journal, date and country of publication, patient group studied, study type, relevant outcomes, results, and study weaknesses of these papers are tabulated. We conclude that Troponin I and T can both be used to indicate myocardial damage, with the level correlating well with the level of injury. However until issues such as a 'gold standard' for peri-operative MI are addressed, one single cut-off point cannot be recommended for either test.     

The multidisciplinary rectal cancer treatment: main convergences, controversial aspects and investigational areas which support the need for an European Consensus.

BACKGROUND AND PURPOSE: During the past decades staging and treatment of rectal cancer are used different in Europe and in North America. To promote a process to integrate the daily practice with the best evidence of the literature an International Conference was organized in Italy. Agreement between Experts, Centres, and specialists who participated in the Conference are reported. METHODS: Five aspects were analyzed and a questionnaire was tailored for this purpose. The questionnaire had 159 questions. During the Conference, at the beginning of each Session, the moderators showed the answers from the Experts and the Centres, and, at the end of the session, the audience voted in all controversial issues. Agreements were scored at three levels: minimum, if it was between 51 and 74% of votes for each group; moderate, between 75 and 94%; large, more than 94%. RESULTS: The main results are: staging: endoanal ultrasound was considered as mandatory in T staging, in the evaluation of sphincter infiltration, and in the restaging of T after chemoradiotherapy (chRT). Magnetic Resonance Imaging is mandatory in the evaluation of mesorectal fascia infiltration. Endoscopy had a moderate agreement for the definition of tumour location, and the barium enema as optional. Digital rectal examination is complementary for staging and PET-CT investigational for T, N and yT staging. Preoperative radiotherapy: for T4 stage chRT was always the preferred treatment, often with moderate agreement, for any tumour location and N status. For T3, chRT received the same agreement except for high location and N0-N1. For T2 stage, N2 and positive nodes outside the mesorectum, chRT received minimum agreement for low and middle tumours; for high tumours only positive nodes outside the mesorectum was agreed upon. Preoperative radiotherapy, negative specimen and sphincter preservation: chRT was agreed by many for all T stages and N presentations of lower third tumours, except for T1-2 N0-N1. Postoperative treatments: the selection for these treatments often received moderate agreement according to the infiltration of surrounding organs, positive nodal status and circumferential radial margins. Therapy of metastatic disease: an agreement was found for FOLFOX as first-line therapy and for FOLFIRI as second-line, although comparative studies show similar activity of FOLFOX and FOLFIRI regimens. CONCLUSIONS: This process represents an expertise opinion process that may contribute to increased scientific debate and to promote the development of 'guidelines', 'clinical recommendations' and ultimately a Consensus on the evolving approach to rectal cancer treatment.     

The Brøset violence checklist (BVC)

OBJECTIVE: The Br?set violence checklist (BVC) is a short-term violence prediction instrument assessing confusion, irritability, boisterousness, verbal threats, physical threats and attacks on objects as either present or absent. The aim of this paper is to describe the evolution and usefulness of the BVC. METHOD: This paper reviews studies on the BVC and discusses implications for further research. RESULTS: Empirical research has shown that it has moderate sensitivity and high specificity with an adequate inter-rater reliability. CONCLUSION: The BVC is a useful instrument for predicting inpatient violence within the next 24-h period. The psychometric properties of the instrument are satisfactory. Results from ongoing studies will give important information on cultural differences, the validity of the BVC in less well staffed wards, the clinical use of the checklist and its ability to predict violence throughout all the hospital stay.