Paul Farand

Review article: Organ per fusion/permeabilityrelated effects of norepinephrine and vasopressin in sepsis

PurposeOne invariable hallmark of severe sepsis is generalized tissue “malperfusion” and hyperpermeability secondary to microcirculatory/capillary leakage. This review focuses on direct and/or indirect influences of norepinephrine, as a standard of care, and vasopressin, as an alternative vasoactive drug, on organ and tissue perfusion/permeability in severe sepsis.SourceEnglish and French language articles and books published between 1966 and 2005 were identified through a computerized Medline search using the terms “sepsis, permeability, norepinephrine and vasopressin”. Relevant publications were retrieved and scanned for additional sources.Principal findingsThere are few randomized clinical trials comparing different vasopressors in sepsis; most available literature consists of clinical reports, animal experiments and occasional reviews. Based on the best current evidence from these sources, we describe the status of major organ perfusion/ permeability in sepsis (i.e., the lung, the kidney, the heart, the intestine/gut) in the context of sepsis-induced organ dysfunction/ failure. Potential and differential therapeutic effects of the vasopressors norepinephrine and arginine-vasopressin, in the setting of sepsis, are identified.ConclusionsIn the treatment of sepsis, arginine-vasopressin exhibits organ-specific heterogeneity in vascular responsiveness, compared to norepinephrine. While norepinephrine is a current standard of care in sepsis, arginine-vasopressin shows promise for the treatment of septic shock.RésuméObjectifUn signe invariable du “sepsis” sévère est la «malperfusion» généralisée et l’hyperperméabilité secondaire à une fuite microcirculatoire ou capillaire. Le présent exposé insiste sur les influences directes ou indirectes de la norépinéphrine, comme norme de soin, et de la vasopressine, comme médicament vasoactif de remplacement, sur la perfusion et la perméabilité organiques et tissulaires durant le “sepsis”.SourceDes articles de langue anglaise et française et des livres publiés entre 1966 et 2005 ont été repérés dans Medline sous les termes «sepsis, permeability, norepinephrine, vasopressin». Les publications pertinentes ont été extraites et examinées à la recherche d’autres sources.Constatations principalesPeu d’études cliniques randomisées comparent les effets des différents vasopresseurs durant le “sepsis”; la documentation consiste surtout en résumés cliniques, expériences sur des animaux et revues occasionnelles. À partir de la meilleure preuve courante relevant de ces sources, nous décrivons l’état de la perfusion et de la perméabilité des organes principaux, c’est-à-dire le poumon, le rein, le cœur, l’intestin/le tube digestif, dans le contexte d’une dysfonction ou d’une défaillance organiques induites par le sepsis. Les effets thérapeutiques potentiels et différentiels de la norépinéphrine et de l’arginine-vasopressine sur le “sepsis” sont établis.ConclusionDans le traitement du “sepsis”, l’arginine-vasopressine, comparée à la norépinéphrine, présente une hétérogénéité de la réactivité vasculaire qui est spécifique à l’organe traité. La norépinéphrine est le médicament couramment utilisé, mais l’arginine-vasopressine semble prometteuse pour traiter le choc septique.

Role of Imaging in Penetrating and Blunt Traumatic Injury to the Heart

Cardiac injury due to blunt or penetrating chest trauma is common and is associated with significant morbidity and mortality. Understanding the mechanisms, types, and complications of cardiac injuries and the roles of various imaging modalities in characterizing them is important for appropriate diagnosis and treatment. These injuries have not been well documented at imaging, but there are now fast and accurate methods for evaluating the heart and associated mediastinal structures. The authors review the broad spectrum of injuries that can result from blunt or penetrating trauma to the chest, as well as the imaging modalities commonly used in the acute trauma setting for evaluation of the heart and mediastinal structures. A pictorial review of both common and, to date, rarely documented cardiac injuries imaged with a variety of modalities is also presented. While many imaging modalities are available, the authors demonstrate the value of multidetector computed tomography (CT) for the initial evaluation of patients with blunt or penetrating chest trauma. With the advent of multidetector CT, imaging of cardiac injury has increased and accurate identification of these rare but potentially lethal injuries has become paramount for improving survival. Selection of the most appropriate modality for evaluation and recognition of the imaging findings in cardiac injuries in the acute trauma setting is important to expedite treatment and improve survival.

Impact of methicillin resistant Staphylococcus aureus contact isolation units on medical care.

Background Patient isolation using contact precautions has gained widespread use to halt MRSA transmission, however supportive data is scarce and concerns regarding patient safety and satisfaction have been raised. At our institution, MRSA patients are isolated on a dedicated ward (cohort isolation), rather than in separate rooms. Our objectives were (1) to determine the proportion of bedside medical visits to patients on an isolation ward, (2) to quantify complications in those patients and (3) to determine if those complications are related to isolation and if they can be prevented. Methods This retrospective case-control study was performed on the two sites of a tertiary teaching hospital in Sherbrooke, QC, Canada. We matched MRSA patients with an admission diagnosis of heart failure or chronic obstructive pulmonary disease to similar non-isolated controls. The proportion of bedside visits was ascertained through the number of progress notes with subjective elements or with a physical examination. Complications were sought through an extensive file review, and events were analysed according to Baker’s CAES causality and preventability scales. Results Overall, 111 patient pairs were analysed (35 with heart failure and 76 with COPD). Isolated patients received less bedside visits (subjective notes/1,000 patient-days: 849.6 vs. 983.3, p = 0,001). Attending physicians (454.5 vs. 451.4, p = 0,02) and residents (347.0 vs. 416.9, p = 0.01) are responsible for this discrepancy, while medical students appear to visit isolated and non-isolated patients equally (116.5 vs. 114.9, p = 0.90). Isolated patients showed a tendency towards longer stay and more preventable complications, although no difference in the total number of complications was observed. Conclusion Isolated patients have less documented care that suggests less bedside visits from the medical staff, which could hamper the therapeutical relationship. Further studies are needed to explain this finding.

Evaluation of Bleeding Risk in Patients Exposed to Therapeutic Unfractionated or Low-Molecular Weight Heparin: A Cohort Study in the Context of a Quality Improvement Initiative

Background: Bleeding associated with the use of unfractionated heparin (UFH) and low-molecular-weight heparin (LMWH) can be a serious complication of health-care management and should be the focus of quality improvement initiatives by institutions. Objective: To measure the incidence of bleeding with UFH and LMWH and evaluate associated risk factors, Methods: An observational cohort study was conducted at a secondary and tertiary care hospital in Canada. All adults receiving therapeutic doses of UFH or LMWH between April 2006 and March 2007, with the exception of cardiac surgery patients, were included. Bleeding episodes were classified per the GUSTO scale. Results: Of 3066 hospitalizations, the incidence of moderate or severe bleeding was 3.5%. Advanced age (OR 1.02. 95% CI 1.01 to 1.04; p< 0.001), female sex (OR 1.80, 95% CI 1.21 to 2.66; p = 0.003), UFH instead of LMWH (OR 4.72, 95% CI 2.17 to 10.30; p< 0.001), creatinine clearance (CrCI) (OR 0.89, 95% CI 0.84 to 0.95; p < 0.001, for a difference of 10 mL/min in CrCI), and supratherapeutic activated partial thromboplastin time (aPTT) (OR 3.88.95% CI 2.25 to 6.69; p < 0.001 for >180 vs <90 seconds) were associated with a higher risk of bleeding in univariate analysis. In a multivariate model without aPTT, CrCI (OR 0.90, 95% CI 0.85 to 0.96; p< 0.001, for a difference of 10 mL/min in CrCI) and UFH (OR 2.35,95% CI 1.11 to 4.98; p = 0.005) were significant predictors of bleeding. Among the bleeding episodes, 31% were in a postoperative context and 15% were following a puncture. Conclusions: Our findings show that CrCI and aPTT values, as well as the type of heparin used, are significant predictors of bleeding in patients receiving UFH or LMWH and that dosages should be adjusted to patient weight. The reason for all supratherapeutic aPTT levels should be sought and corrective measures taken immediately.

Adventitia: the vital wall of conduit arteries

Adventitia surrounds, nourish, and protect large conductance vessels. This important outer layer has long been forgotten by researchers because interest in vascular diseases has focused mainly on resistance arteries, as shown by the numerous publications on the subject. However, involvement of large vessels in the pathogenesis of vascular diseases is beginning to be recognized. Indeed, the stiffness of conductance arteries could be a precursor event of high blood pressure. Pathological changes that occur in adventitia, increased vasa vasorum permeability for example, may lead or precipitate vascular diseases. Adventitia can also be affected by luminal events like shear stress and possibly atherosclerosis that may trigger adverse responses in the adventitial tissue. These adventitial changes and interrelationships, as well as the structure, including the afferent and efferent autonomic nervous system, and functions of adventitia are the subject of the present review. There is no doubt that the medical and scientific community would greatly benefit from awareness and a better consideration of adventitia and that more studies focusing on this part of blood vessels will lead to an improved comprehension of the different diseases affecting them.

Pilot study: can older inactive adults learn how to reach the required intensity of physical activity guideline?

Most individuals do not reach the recommended physical activity level of at least 150 minutes of aerobic exercise (AE) at moderate-to-vigorous intensity per week. For example, only 13% of older Canadian adults reach World Health Organization physical activity guideline (PAG). One of the reasons might be a difficulty identifying the required intensity. Twenty-five inactive older adults received one session about the AE-PAG and how to use a tool or strategy to help them identify AE intensity: heart-rate (HR) monitor (% of maximal HR; N = 9); manual pulse (% of maximal HR; N = 8); or pedometer (walking cadence; N = 8). Participants had 8 weeks to implement their specific tool with the aim of reaching the PAG by walking at home. At pre- and post-intervention, the capacity to identify AE intensity and AE time spent at moderate-to-vigorous intensity were evaluated. Only the two groups using a tool increased total AE time (both P < 0.01), but no group improved the time spent at moderate-to-vigorous intensity. No significant improvement was observed in the ability to correctly identify AE intensity in any of the groups, but a tendency was observed in the pedometer group (P = 0.07). Using walking cadence with a pedometer should be explored as a tool to reach the PAG as it is inexpensive, easy to use, and seemed the best tool to improve both AE time and perception of intensity.

Effect of age and sex on echocardiographic left ventricular diastolic function parameters in patients with preserved ejection fraction and normal valvular function

BACKGROUND We conducted a retrospective study to specify the effect of age and gender on echocardiographic left ventricular diastolic function parameters. METHODS We included echocardiograms done in our institution between 1995 and 2007, for which data on diastolic function were available. In order to target a population as close aspossible to healthy subjects, echocardiograms reporting abnormal contraction, valvulopathy or extreme data were excluded. RESULTS A total of 14,298 patients (mean age 58.53 years; men 49.1%) were included in the study. Sex did not influence E/A ratio (p = 0.298) but age decreased it significantly (p < 0.001). E/e ratio increased significantly with age (p < 0.001) and was higher in women than in men (p < 0.001). After the age of 40, more than 10% of the patients had an E/e ratio superior than 8. CONCLUSIONS To our knowledge, this is the most imposing study - in terms of number of patients from first to tenth decade of life that were included - addressing the effect of age and gender on diastolic function. Our results stress the need for future prospective trials to establishnormal diastolic function parameters according to age and gender, notably for the E/e ratio for which a significant proportion of our population had a ratio superior of what is actually considered normal.

Acute and recurring pericarditis: More colchicine, less corticosteroids.

Acute and recurring pericarditis are frequently encountered clinical entities. Given that severe complications such as tamponade and constrictive pericarditis occur rarely, the majority of patients suffering from acute pericarditis will have a benign clinical course. However, pericarditis recurrence, with its painful symptoms, is frequent. In effect, recent studies have demonstrated a beneficial role of colchicine in preventing recurrence, while also suggesting an increase in recurrences with the use of corticosteroids, the traditional first-line agent.

Delayed efficient anticoagulation with heparin in patients with a weight of 110 kg and more treated for acute coronary syndrome.

The use of a weight‐based nomogram is considered as standard care for prescribing appropriate doses of unfractionated heparin (UFH). Because of the need for multiple other medications that may affect bleeding and that clinical data have relied on similar dosing algorithms, maximum initial bolus and infusion rates have been suggested (capped initial dose). Whether these weight‐based heparin nomograms properly address therapeutic dosing in obese patients remains questionable.

Arrhythmic Risk Following Recovery of Left Ventricular Ejection Fraction in Patients with Primary Prevention ICD.

Left ventricular ejection fraction (LVEF) recovers during follow‐up in a significant proportion of patients implanted with a cardioverter defibrillator (ICD) for primary prevention. Little is known about the midterm arrhythmic risk in this population, particularly in relation to the presence or absence of ischemic cardiomyopathy.