Critical distance methods are extremely useful for predicting fracture and fatigue in engineering components and represent an important development in the theory of fracture mechanics. Despite being ...in use for over fifty years in some fields, there has never been a book about these methods until now. The increasing use of computer-aided stress analysis has made these methods extremely easy to use in practical situations. This is turn has prompted researchers to re-examine the underlying theory with renewed interest. The book begins with a general introduction to the phenomena of mechanical failure in materials. After a simple explanation of how to use critical distance methods, and a more detailed exposition of the methods including their history and classification, the book continues by showing examples of how critical distance approaches can be applied to predict fracture and fatigue in different classes of materials. Subsequent chapters include some more complex theoretical areas, such as multiaxial loading and contact problems, and a range of practical examples using case studies of real engineering components. This book will be of interest to academic researchers, industrial engineers and research students.
The study aims to assess characteristics and outcomes of patients suffering a mechanical complication (MC) after ST-segment elevation myocardial infarction (STEMI) in a contemporary cohort of ...patients in the percutaneous coronary intervention era.
This retrospective single-center cohort study encompasses 2508 patients admitted with STEMI between March 9, 2009 and June 30, 2014. A total of 26 patients (1.1%) suffered a mechanical complication: ventricular septal rupture (VSR) in 17, ventricular free wall rupture (VFWR) in 2, a combination of VSD and VFWR in 2, and papillary muscle rupture (PMR) in 5 patients. Older age (74.5 ± 10.4 years versus 63.9 ± 13.1 years, p < 0.001), female sex (42.3% versus 23.3%, p = 0.034), and a longer latency period between symptom onset and angiography (> 24h: 42.3% versus 16.2%, p = 0.002) were more frequent among patients with MC as compared to patients without MC. The majority of MC patients had multivessel disease (77%) and presented in cardiogenic shock (Killip class IV: 73.1%). Nine patients (7 VSR, 2 VFWR & VSR) were treated conservatively and died. Out of the remaining 10 VSR patients, four underwent surgery, three underwent implantation of an occluder device, and another three patients had surgical repair following occluder device implantation. All patients with isolated VFWR and PMR underwent emergency surgery. At 30 days, mortality for VSR, VFWR, VFWR & VSR and PMR amounted to 71%, 50%, 100% and 0%, respectively.
Despite advances in the management of STEMI patients, mortality of mechanical complications stays considerable in this contemporary cohort. Older age, female sex, and a prolonged latency period between symptom onset and angiography are associated with the occurrence of these complications.
The most common mechanical complications of acute myocardial infarction include free-wall rupture, ventricular septal rupture (VSR), papillary muscle rupture and pseudoaneurysm. It is rare for a ...patient to experience more than one mechanical complication simultaneously. Here, we present a case of ST-segment elevation myocardial infarction (STEMI) complicated with three mechanical complications, including ventricular apical wall rupture, ventricular aneurysm formation and ventricular septal dissection (VSD) with VSR. Cardiac auscultation revealed rhythmic S1 and S2 with a grade 3 holosystolic murmur at the left sternal border. Electrocardiogram indicated anterior ventricular STEMI. Serological tests showed a significant elevated troponin I. Bedside echocardiography revealed ventricular apical wall rupture, apical left ventricle aneurysm and VSD with VSR near the apex. This case demonstrates that several rare mechanical complications can occur simultaneously secondary to STEMI and highlights the importance of bedside echocardiography in the early diagnosis of mechanical complications.
Objectives
To perform a systematic review of all cases of spontaneous rupture of the urinary bladder (SRUB) and to describe the demographic data, associated comorbidities, clinical presentation, ...diagnosis, relevant laboratory findings, associated factors, management, morbidity and mortality associated with the presentation of SRUB.
Methods
The study protocol was registered with the International Prospective Register of Systematic Reviews (PROSPERO). A search was carried out across the following electronic databases: PubMed, Web of Science, Scopus, Google Scholar and the Cochrane Database of Systematic Reviews. Full texts of selected studies were analysed, and data extracted. The review was reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta‐Analyses (PRISMA).
Results
A total of 278 articles comprising 240 case reports and 38 case series, with a total of 351 patients were included. The median (interquartile range IQR) age of all included patients was 47.5 (33–65) years. The median (IQR) time to presentation was 48 (24–96) h, with the major presenting symptom being abdominal pain (76%). In patients in whom the diagnosis was made prior to any intervention, the condition was misdiagnosed in 64% of cases. The diagnosis was confirmed during explorative open surgery in 42% of cases. Pelvic radiation (13%) and alcohol intoxication (11%) were the most common associated factors. Intraperitoneal rupture (89%) was much more common, with the dome of the bladder being most frequently involved (55%). The overall mortality was 15%.
Conclusion
This review identified a number of key factors that appear to be associated with an increased incidence of SRUB. It also emphasized the high rate of misdiagnosis and challenge in confirming the diagnosis. Overall, it highlighted the importance of the need for increased awareness and maintaining a high index of suspicion for this condition.
In France, the frequency of premature rupture of the membranes (PROM) is 2%–3% before 37 weeks' gestation (level of evidence LE 2) and less than 1% before 34 weeks (LE2). Preterm delivery and ...intrauterine infection are the major complications of preterm PROM (PPROM) (LE2). Prolongation of the latency period is beneficial (LE2). Compared with other causes of preterm delivery, PPROM is associated with a clear excess risk of neonatal morbidity and mortality only in cases of intrauterine infection, which is linked to higher rates of in utero fetal death (LE3), early neonatal infection (LE2), and necrotizing enterocolitis (LE2).
The diagnosis of PPROM is principally clinical (professional consensus). Tests to detect IGFBP-1 or PAMG-1 are recommended in cases of uncertainty (professional consensus).
Hospitalization is recommended for women diagnosed with PPROM (professional consensus). Adequate evidence does not exist to support recommendations for or against initial tocolysis (Grade C). If tocolysis is prescribed, it should not continue longer than 48 h (Grade C). The administration of antenatal corticosteroids is recommended for fetuses with a gestational age less than 34 weeks (Grade A) and magnesium sulfate if delivery is imminent before 32 weeks (Grade A). The prescription of antibiotic prophylaxis at admission is recommended (Grade A) to reduce neonatal and maternal morbidity (LE1). Amoxicillin, third-generation cephalosporins, and erythromycin (professional consensus) can each be used individually or eythromycin and amoxicillin can be combined (professional consensus) for a period of 7 days (Grade C). Nonetheless, it is acceptable to stop antibiotic prophylaxis when the initial vaginal sample is negative (professional consensus). The following are not recommended for antibiotic prophylaxis: amoxicillin-clavulanic acid (professional consensus), aminoglycosides, glycopeptides, first- or second-generation cephalosporins, clindamycin, or metronidazole (professional consensus).
Women who are clinically stable after at least 48 h of hospital monitoring can be managed at home (professional consensus).
Monitoring should include checking for clinical and laboratory factors suggestive of intrauterine infection (professional consensus). No guidelines can be issued about the frequency of this monitoring (professional consensus). Adequate evidence does not exist to support a recommendation for or against the routine initiation of antibiotic therapy when the monitoring of an asymptomatic woman produces a single isolated positive result (e.g., elevated CRP, or hyperleukocytosis, or a positive vaginal sample) (professional consensus).
In cases of intrauterine infection, the immediate intravenous administration (Grade B) of antibiotic therapy combining a beta-lactam with an aminoglycoside (Grade B) and early delivery of the child are both recommended (Grade A). Cesarean delivery of women with intrauterine infections is reserved for the standard obstetric indications (professional consensus).
Expectant management is recommended for uncomplicated PROM before 37 weeks (Grade A), even when a sample is positive for Streptococcus B, as long as antibiotic prophylaxis begins at admission (professional consensus). Oxytocin and prostaglandins are two possible options for the induction of labor in women with PPROM (professional consensus).
Background:
The optimal treatment of acute Achilles tendon ruptures for active patients is under debate.
Purpose:
To compare clinical outcomes and calf muscle strength recovery after the nonsurgical ...treatment and open surgical repair of acute Achilles tendon ruptures with identical accelerated rehabilitation programs.
Study Design:
Randomized controlled trial; Level of evidence, 1.
Methods:
From 2009 to 2013, a total of 60 patients with an acute Achilles tendon rupture were randomized to surgery or nonsurgical treatment. Nonsurgical treatment included first a week of cast immobilization, followed by a functional orthosis for 6 weeks, allowing full weightbearing after week 1 and active plantar flexion after week 5. Surgery was simple end-to-end open repair, and postoperative treatment was identical to nonsurgical treatment. Outcome measures included the Leppilahti Achilles tendon performance score, isokinetic calf muscle strength, and RAND 36-Item Health Survey at 18-month follow-up.
Results:
At 18-month follow-up, the mean Leppilahti score was 79.5 and 75.7 for the surgically and nonsurgically treated groups, respectively (mean difference, 3.8; 95% CI, –1.9 to 9.5; P = .19). Angle-specific peak torque results of affected legs showed that surgery resulted in faster and better recovery of calf muscle strength over the entire range of motion of the ankle joint: at 6 months, the difference varied from 16% to 24% (P = .016), favoring the surgically treated group, whereas at 18 months, surgically treated patients had 10% to 18% greater strength results (P = .037). At 18 months, a 14% difference in the peak torque of the affected leg favored the surgical group versus the nonsurgical group (mean peak torque, 110.3 vs 96.5 N·m, respectively; mean difference, 13.6 N·m; 95% CI, 2.0-25.1 N·m; P = .022). The RAND 36-Item Health Survey indicated better results in the domains of physical functioning (P = .006) and bodily pain (P = .037) for surgically treated patients.
Conclusion:
Surgical and nonsurgical treatments of acute Achilles tendon ruptures have similar results in terms of the Achilles tendon performance score, but surgery restores calf muscle strength earlier over the entire range of motion of the ankle joint, with a 10% to 18% strength difference favoring surgery at 18 months. Surgery may also result in better health-related quality of life in the domains of physical functioning and bodily pain compared with nonsurgical treatment.
Registration:
NCT02012803 (ClinicalTrials.gov)
Inflammation and plaque vulnerability Hansson, G. K.; Libby, P.; Tabas, I.
Journal of internal medicine,
November 2015, Letnik:
278, Številka:
5
Journal Article
Recenzirano
Odprti dostop
Atherosclerosis is a maladaptive, nonresolving chronic inflammatory disease that occurs at sites of blood flow disturbance. The disease usually remains silent until a breakdown of integrity at the ...arterial surface triggers the formation of a thrombus. By occluding the lumen, the thrombus or emboli detaching from it elicits ischaemic symptoms that may be life‐threatening. Two types of surface damage can cause atherothrombosis: plaque rupture and endothelial erosion. Plaque rupture is thought to be caused by loss of mechanical stability, often due to reduced tensile strength of the collagen cap surrounding the plaque. Therefore, plaques with reduced collagen content are thought to be more vulnerable than those with a thick collagen cap. Endothelial erosion, on the other hand, may occur after injurious insults to the endothelium instigated by metabolic disturbance or immune insults. This review discusses the molecular mechanisms involved in plaque vulnerability and the development of atherothrombosis.
Infectious mononucleosis Lennon, Paul; Crotty, Michael; Fenton, John E
BMJ (Online),
04/2015, Letnik:
350, Številka:
apr21 2
Journal Article, Book Review
Recenzirano
Odprti dostop
Infectious mononucleosis is commonly seen in both the community and the hospital setting. Patients usually present with a sore throat and often presume that an antibiotic is required. It is therefore ...important to dispel the many myths relating to the condition with appropriate patient education. Knowledge of the clinical course of the disease, as well as potential complications, is paramount. In an information age, difficult questions may arise for a general practitioner, emergency doctor, or trainee in ear, nose, and throat medicine. The aim of this review is to assist those who encounter infectious mononucleosis in the adolescent and adult population.
Aims To determine the incidence and factors associated with heart rupture (HR) in acute coronary syndrome (ACS) patients. Methods and results Among 60 198 patients, 273 (0.45%) had HR (free wall ...rupture, n = 118; ventricular septal rupture, n = 155). Incidence was 0.9% for ST-segment elevation myocardial infarction (STEMI), 0.17% for non-STEMI, and 0.25% for unstable angina. Hospital mortality was 58 vs. 4.5% in patients without HR (P < 0.001). The incidence was lower in STEMI patients with primary percutaneous coronary intervention (PCI) than in those without (0.7 vs. 1.1%; P = 0.01), but primary PCI was not independently related to HR in adjusted analysis (P = 0.20). Independent variables associated with HR included: ST-segment elevation (STE)/left bundle branch block; ST-segment deviation; female sex; previous stroke; positive initial cardiac biomarkers; older age; higher heart rate; systolic blood pressure/30 mmHg decrease. Conversely, previous MI and the use of low-molecular-weight heparin and beta-blockers during first 24 h were identified as protective factors for HR. Conclusion The incidence of HR is low in patients with ACS, although its incidence is probably underestimated. Heart rupture occurs more frequently in ACS with STE and is associated with high hospital mortality. A number of variables are independently related to HR.
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