More proof of older physicians’ knowledge gaps

The more a physian has been in practice, the less likely he is to prescribe an evidence-based therapy, as the graphic shows.

Austin PC, Tu JV, Ko DT, Alter DA. Factors associated with the use of evidence-based therapies after discharge among elderly patients with myocardial infarction. Can Med Ass J. 2008;179(9):901-8

Neuroanatomical substrate of gender cognitive differences

Certain cognitive functions differ in men and women, although the anatomical and functional substrates underlying these differences remain unknown. Because neocortical activity is directly related with higher brain function, numerous studies have focused on the cerebral cortex when searching for possible structural correlates of cognitive gender differences. However, there are no studies on possible gender differences at the synaptic level. In the present work we have used stereological and correlative light and electron microscopy to show that men have a significantly higher synaptic density than women in all cortical layers of the temporal neocortex. These differences may represent a microanatomical substrate contributing to the functional gender differences in brain activity.

Alonso-Nanclares L, Gonzalez-Soriano J, Rodriguez JR, DeFelipe J. Gender differences in human cortical synaptic density. Proc Natl Acad Sci USA. 2008;105(38):14615-9.

DOI : 10.1073/pnas.0803652105

Socialists are wrong, NEJM says

To this day, I fail to understand the major tenet of the socialist medicine ideology, that is, higher mortality of the lower socioeconomical classes is determined by the subpar medical care they receive. Hence, socialists say, we must strive to close the gap between the rich and the poor by providing better healthcare to the latter group. 

From the very first glance, the thesis seems quite baseless as it is a very well-known fact that the contribution of healthcare to life expectancy is marginal at best. Therefore, any differences in mortality between the rich and the poor are probably better explained by baseline differences in health status (which, in turn, may be due to lifestyle choices, stress, and so on) rather than by inequalities in health care. Indeed, this mortality gap is as “surprising” as the one we would note between trained athletes and overweight couch potatoes.

This self-evident truth has recently been confirmed in a large, European, survey of health inequalities published in the New England Journal of Medicine :

In Europe as a whole, deaths from conditions amenable to medical intervention account for 5% of inequalities in the rate of death of any cause. [1]

 

Even more of interest is the finding that reduction of poverty, by itself, does not reduce inequalities in health, highlighting the fact that the problem is not one of access to health ressources, but of education, and maybe even of intelligence. 

 

Within western Europe, there is little evidence that among-country variations in the magnitude of inequalities in health are related to variations in political factors. For example, Italy and Spain have welfare policies that are less generous and less universal than those of northern Europe, but they appear to have substantially smaller inequalities in mortality [...].

We also found no evidence for systematically smaller inequalities in health in countries in northern Europe. This is surprising, because these countries have long histories of egalitarian policies, reflected by, among other things, welfare policies. These policies provide a high level of social-security protection to all residents of the country, resulting in smaller income inequalities and lower poverty rates. [...] Lifestyle-related risk factors have an important role in premature death in high-income countries and also appear to contribute to the persistence of inequalities in mortality in the northern region.  [1]

 

This important study shows that any medical intervention aimed at reducing the gap in health between different socioeconomical classes is doomed to failure and will achieve nothing more that diverting scarce resources from treatments that benefit to the whole of society.

 

1. Mackenbach JP, Stirbu I, Roskam AJ, et al. Socioeconomic inequalities in health in 22 European countries. N Engl J Med. 2008;358(23):2468-81.

 

 

Saline vs. Ringer’s lactate: where is the evidence?

Two very similar* animal studies show that in the setting of acute hemorrhage, less ringer’s lactate than 0,9 % saline is required to achieve a target mean arterial pressure. (1,2)

One human RCT demonstrated that, compared to ringer’s lactate, saline fluid replacement during aortic aneuvrysm repair is associated with larger needs of blood products, but had no effect on  intensive care or hospital stay, nor on complications rates. (3)  Yet another RCT concludes that in patients undergoing abdominal surgery, both fluids resulted in similar levels of mild coagulopathy and no difference in blood loss. Normal anion gap dilutional/hyperchloremic acidosis** occured only in patients repleted with saline, however. (4)

There is no proven adverse consequences to hyperchloremic acidosis and, as such, current evidence does not permit, in my opinion, to favor any one of the usual resuscitation fluids over the other.

 

 

 

* I seriously wonder if this similarity explains the failure of the later paper’s authors to acknowledge the work of their predecessors.

** To my best knowledge, whether acidosis occurs due to the addition of chloride anions or to the dilution of bicarbonate buffers is far from being established. See Anesthesiology. 87(4):1009-1014 for a lovely discussion of possible mecanisms.

 

 

 

1. Kiraly LN, Differding JA, Enomoto TM, et al. Resuscitation with normal saline (NS) vs. lactated ringers (LR) modulates hypercoagulability and leads to increased blood loss in an uncontrolled hemorrhagic shock swine model. J Trauma. 2006;61(1):57-64

2.  Todd SR, Malinoski D, Muller PJ, Schreiber MA. Lactated Ringer’s is superior to normal saline in the resuscitation of uncontrolled hemorrhagic shock. J Trauma. 2007;62(3):636-9

3. Waters JH, Gottlieb A, Schoenwald P, Popovich MJ, Sprung J, Nelson DR. Normal saline versus lactated Ringer’s solution for intraoperative fluid management in patients undergoing abdominal aortic aneurysm repair: an outcome study. Anesth Analg. 2001 Oct;93(4):817-22

4. Boldt J, Haisch G, Suttner S, Kumle B, Schellhase F. Are Lactated Ringer’s Solution and Normal Saline Solution Equal with Regard to Coagulation? Anesth Analg 2002;94:378–84

Dog learns to "pray" for treats

http://news.bbc.co.uk/1/hi/world/asia-pacific/7310993.stm

http://www.mirror.co.uk/news/2008/03/24/conan-the-chihuahua-prays-at-temple-in-japan-89520-20361753/

Fecal carriage of MDR Acinetobacter baumanii

Fecal colonization with multiresistant Acinetobacter baumannii was evaluated in 189 consecutive patients in intensive care units (ICUs) during two different 2-month periods (October-November 1993 and May-June 1994). Rectal swabs were obtained weekly from admission to discharge from the ICU. Overall, 77 patients (41%) had multiresistant A. baumannii fecal colonization; colonization was detected in 55 (71%) of the patients within the first week of their ICU stay. Clinical infections due to multiresistant A. baumannii occurred more frequently in patients with fecal colonization than in those without fecal colonization (26% vs. 5%, respectively; P < .001). The reinforcement of isolation measures between study periods reduced both the number of fecal carriers of multiresistant A. baumannii (from 52% to 31%; P < .01) and the number of patients with multiresistant A. baumannii infections (from 17% to 11%; no statistical significance). The digestive tract of ICU patients could be an important epidemiologic reservoir for multiresistant A. baumannii infections in hospital outbreaks. Further prospective studies should be undertaken to define the relative significance of digestive tract colonization compared with other body site colonizations.

 Corbella X, et al. Relevance of digestive tract colonization in the epidemiology of nosocomial infections due to multiresistant Acinetobacter baumannii.Clin Infect Dis. 1996;23(2):329-34

RCT shows reduction in mortality and acquisition of resistant bacteria in the ICU

A large RCT convincingly proves that SDD reduces mortality and does not entail the emergence of resistant bacteria.

In the SDD group 69 (15%) patients died in the ICU compared with 107 (23%) in the control group (p=0.002). Hospital mortality was lower in the SDD groups than in the control group (113 [24%] vs 146 [31%], p=0.02). During their stay in intensive care, colonisation with gram-negative bacteria resistant to ceftazidime, ciprofloxacin, imipenem, polymyxin E, or tobramycin occurred in 61 (16%) of 378 SDD patients and in 104 (26%) of 395 patients in the control group (p=0.001). Colonisation with vancomycin-resistant enterococcus occurred in five (1%) SDD patients and in four (1%) controls (p=1.0). No patient in either group was colonised with meticillin-resistant Staphylococcus aureus. 

de Jonge et al. Effects of selective decontamination of digestive tract on mortality and acquisition of resistant bacteria in intensive care: a randomised controlled trial. The Lancet 2003; 362:1011-1016

 

DOI:10.1016/S0140-6736(03)14409-1