Chest compressions alone may be more effective than standard cardiopulmonary resuscitation (CPR) for cardiac arrest patients in out-of-hospital setting, according to a Japanese study.
In the study, 46 percent of patients who received compression-only CPR were alive a month after cardiac arrest compared with 39.9 percent of those who received standard CPR with rescue breathing. Moreover, those who received compression-only CPR were 40.7 percent more likely to preserve brain function (as measured on a 5-point cerebral performance scale) compared with 32.9 percent in those receiving conventional CPR. [Circulation 2012;126:2844-2851]
“The data suggest that compression-only CPR should be the standard and conventional CPR with rescue breathing the option,” said lead investigator Dr. Taku Iwami from the department of preventive services in Kyoto University School of Public Health, Japan.
Iwami and colleagues reviewed the records of 1,376 individuals who had sudden cardiac arrests of presumed cardiac origin over a 5-year period. Each of them received CPR from bystanders followed by shocks using publicly-accessed defibrillators.
Among the study cohort, 37 percent received compression-only CPR while 63 percent received standard CPR. Prior to hospital admission, spontaneous circulation returned in 50.2 percent of patients receiving compression-only CPR and in 40.5 percent of those receiving standard CPR (p<0.001).
“This goes to show that the combination of early defibrillation and compression-only CPR by bystanders is the best way to save lives after sudden cardiac arrests,” the authors said.
Chest compressions alternating with rescue breathing remains the standard for trained rescuers. However, recommendation for untrained rescuers switched to only chest compressions regardless of emergency dispatch assistance in 2010. This was because rescue breathing is difficult to perform and can interrupt chest compressions, said Iwami.
Despite this, many people are still hesitant to perform CPR with rescue ventilation for fear they may do more harm to the patient. What they are not aware of is that chest compressions, even by those who are not trained in conventional CPR, can help a patient maintain blood flow to the heart and brain until a defibrillator gets the heart pumping again.
“We need to encourage chest compression-only CPR and public access defibrillation programs,” Iwami said. “Doing something is better than nothing.”
Dr. Michael Sayre of the University of Washington in Seattle, US, and spokesperson for the American Heart Association, said many people are dying from cardiac arrest because family members and friends are unsure how to help. The findings confirm that hands-on CPR is highly effective and is easy to do, he added.http://www.mims.com/Indonesia/pub/topic/Medical%20Tribune/2013-03/Compression-only%20CPR%20saves%20more%20lives?token=rnp4v0BfyQa5o3iSS1Uv5Ry6TWCP4H8SXzFN8QDJQWvspgHFYCA8hAPu41olpOmW3vr%2fgB8gvkMKWl5SuULZGmQWwSayeXpIXCS0PgyyJYA37UHiZeai7pULdfk67aMbyr4GUpBdzlxkw4CvmSbxxQBuSqfkGE%2bgDS3Mp3ngH19ooURzIC3fBUmjr9T%2fF8KG7W6FpzNyjIGc%2fz8vGlQyPD9%2fZLCzJJGnJNg844f%2b2GA%3d
Thursday, March 28, 2013
Sunday, March 10, 2013
Selenium supplementation for the primary prevention of cardiovascular disease
Background: Selenium is a key component of a number of selenoproteins which protect against oxidative stress and have the potential to prevent chronic diseases including cardiovascular disease (CVD). However, observational studies have shown inconsistent associations between selenium intake and CVD risk; in addition, there is concern around a possible increased risk of type 2 diabetes with high selenium exposure.
Objectives:To determine the effectiveness of selenium only supplementation for the primary prevention of CVD and examine the potential adverse effect of type 2 diabetes.
Search methods: The following electronic databases were searched: the Cochrane Central Register of Controlled Trials (CENTRAL) (Issue 10 of 12, October 2012) onThe Cochrane Library; MEDLINE (Ovid) (1946 to week 2 October 2012); EMBASE Classic + EMBASE (Ovid) (1947 to 2012 Week 42); CINAHL (EBSCO) (to 24 October 2012); ISI Web of Science (1970 to 24 October 2012); PsycINFO (Ovid) (1806 to week 3 October 2012); Database of Abstracts of Reviews of Effects (DARE), Health Technology Assessment Database and Health Economics Evaluations Database (Issue 4 of 4, October 2012) on The Cochrane Library. Trial registers and reference lists of reviews and articles were searched and experts in the field were approached. No language restrictions were applied.
Selection Criteria: Randomised controlled trials on the effects of selenium only supplementation on major CVD end-points, mortality, changes in CVD risk factors, and type 2 diabetes were included both in adults of all ages from the general population and in those at high risk of CVD. Trials were only considered where the comparison group was placebo or no intervention. Only studies with at least three months follow-up were included in the meta-analyses, shorter term studies were dealt with descriptively.
Data collection and analysis: Two review authors independently assessed trial quality and extracted data. Study authors were contacted for additional information.
Main results: Twelve trials (seven with duration of at least three months) met the inclusion criteria, with 19,715 participants randomised. The two largest trials that were conducted in the USA (SELECT and NPC) reported clinical events. There were no statistically significant effects of selenium supplementation on all cause mortality (RR 0.97, 95% CI 0.88 to 1.08), CVD mortality (RR 0.97, 95% CI 0.79 to 1.2), non-fatal CVD events (RR 0.96, 95% CI 0.89 to 1.04) or all CVD events (fatal and non-fatal) (RR 1.03, 95% CI 0.95 to 1.11). There was a small increased risk of type 2 diabetes with selenium supplementation but this did not reach statistical significance (RR 1.06, 95% CI 0.97 to 1.15). Other adverse effects that increased with selenium supplementation, as reported in the SELECT trial, included alopecia (RR 1.28, 95% CI 1.01 to 1.62) and dermatitis grade 1 to 2 (RR 1.17, 95% CI 1.0 to 1.35). Selenium supplementation reduced total cholesterol but this did not reach statistical significance (WMD - 0.11 mmol/L, 95% CI - 0.3 to 0.07). Mean high density lipoprotein (HDL) levels were unchanged. There was a statistically significant reduction in non-HDL cholesterol (WMD - 0.2 mmol/L, 95% CI - 0.41 to 0.00) in one trial of varying selenium dosage. None of the longer term trials examined effects on blood pressure. Overall, the included studies were regarded as at low risk of bias.
Authors' conclusions: The limited trial evidence that is available to date does not support the use of selenium supplements in the primary prevention of CVD.
Clinical Summary
Diet is a key factor in a person’s risk of cardiovascular disease and selenium is one of the dietary elements that might play a role in reducing this risk. It is a key component of a number of selenoproteins, which protect against oxidative stress and have the potential to prevent chronic diseases, including cardiovascular disease. However, observational studies have shown inconsistent associations between selenium intake and cardiovascular disease, and concerns have been raised about a possible increased risk of type 2 diabetes with high selenium exposure.
Use of selenium enriched foods, supplements and fertilizers has increased in recent years in many countries because of the perception that selenium may reduce the risk of cardiovascular disease and other chronic conditions. Therefore, it is important to understand the effects of a nutrient that is so frequently supplemented, and this needs to be done for both the potential benefits on cardiovascular disease and the potential harms on diabetes. This Cochrane Review received funding from the National Institute for Health Research’s systematic review programme in the UK in order to examine the effects of providing selenium supplements to healthy adults as a means of preventing the occurrence of cardiovascular disease. This was a primary aim of the review but it also included an assessment of whether selenium supplements would reduce risk factors associated with cardiovascular disease, but found that the evidence was too limited to look at this properly.
The review found 12 trials in which nearly 20,000 healthy adults were randomly assigned to receive either selenium supplements or a placebo. Overall, the included studies were regarded as at low risk of bias. The vast majority of participants were men living in the USA, where people are already well nourished and obtain large amounts of selenium from natural foods. Furthermore, most of these men were in just two of the trials: SELECT and NPC, with SELECT having been set up as a trial of the effects of selenium supplementation on cancer.
Considering the main results selenium supplements did not lead to any statistically significant difference in the risk of death due to cardiovascular disease or any other cause when compared to taking a placebo. There was also no effect detected on the occurrence of non-fatal cardiovascular disease events
The possibility of an adverse effect of increasing the risk of type 2 diabetes, which has been suggested in some previous studies, could not be ruled out by the analyses that were possible in the review. Supplements were associated with a small increase in risk, but this was not statistically significant. Minor side effects reported in the largest trial included hair loss and skin problems.
In summary, the authors conclude that the limited evidence available at this time does not support the use of selenium supplements as a means of preventing cardiovascular disease in healthy people. They suggest that taking selenium supplements is probably neither beneficial nor harmful, but would like to see more evidence before being confident that there is not a small increased risk of type 2 diabetes.
They also emphasise how most of the current evidence on selenium and cardiovascular disease comes from American adults, who are already getting adequate levels of selenium in their daily diets. This means that the trials they reviewed involved healthy people rather than those who might be predisposed to selenium deficiency and they call for research into the effects of selenium supplements in less well nourished populations, where dietary intake of the element is lower. However, based on the current evidence, their bottom line is that the indiscriminate and widespread use of selenium supplements for the prevention of cardiovascular disease in people with adequate or high selenium status is not justified and should not be encouraged.
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