Journal watch: Recent studies of note

Recent studies about tight glucose control, radial PCI vs. femoral PCI, and other topics.


Tight glucose control may not help critically ill

Tight glucose control may not improve outcomes in critically ill patients and may increase rates of hypoglycemia, a new study found.

Current guidelines from the American Diabetes Association and other groups recommend tight control of glucose levels in critically ill patients, based mainly on a 2001 trial that found a one-third reduction in mortality with tight glucose control in surgical ICU patients. More recent trials have found mixed results.

The authors did a meta-analysis that included 29 randomized, controlled trials with 8,432 patients conducted in adult ICUs that compared tight glucose control (goal glucose level <150 mg/dL) with usual care and examined in-hospital or short-term mortality rates, hypoglycemia, septicemia or new dialysis as primary or secondary end points.The results appeared in the Aug. 27 Journal of the American Medical Association.

Tight glucose control in critically ill patients had no significant effect on hospital mortality rates but increased the risk for hypoglycemia (13.7% risk for tightly controlled patients versus 2.5% for usual care patients), defined as a glucose level less than or equal to 40 mg/dL. A significant reduction in septicemia for tightly controlled glucose patients seemed to be confined mainly to surgical ICU patients. The available evidence does not support tight glucose control in all critically ill patients, and reevaluation of current guidelines is in order until more evidence from larger trials is available, the authors said.

Bleeding complication rates lower with radial PCI vs. femoral PCI

The seldom-used radial approach to percutaneous coronary intervention (r-PCI) results in lower rates of bleeding and vascular complications than the popular femoral approach (f-PCI), though both are equally effective at unclogging arteries, a new study found.

Researchers analyzed data from 593,094 procedures in the National Cardiovascular Data Registry on the use and outcomes of r-PCI. They used logistic regression to evaluate the adjusted association between r-PCI and procedural success, bleeding complications, and vascular complications, looking especially at high-risk-of-bleeding patients like the elderly, women, and those with acute coronary syndrome. The results appear in the August Journal of the American College of Cardiology: Cardiovascular Interventions.

R-PCI procedures only accounted for 1.3% of total procedures, yet were associated with a similar rate of procedural success (adjusted odds ratio [OR], 1.02 [95% CI, 0.93 to 1.12]) and a significantly lower risk for bleeding complications (OR, 0.42) after multivariable adjustment. The reduction in bleeding complications was more pronounced among women, patients younger than 75 years old, and patients undergoing PCI for acute coronary syndrome.

R-PCI may be used infrequently because of the learning curve associated with the technique, doctors' unwillingness to adopt a new approach, and concerns over long fluoroscopy times, the study's authors said. Still, the results of the current study suggest that wider adoption of radial PCI in clinical practice could improve the safety of the procedure, especially for higher-risk patients, they wrote.

Cardiac resynchronization therapy not used appropriately in U.S. hospitals, study suggests

Cardiac resynchronization therapy (CRT) is not used according to current guidelines in U.S. hospitals, a new study reports. American Heart Association researchers examined how closely CRT use follows the American College of Cardiology/ American Heart Association 2005 guidelines, which recommend CRT in patients with a left ventricular ejection fraction of 35% or less, a QRS greater than 120 milliseconds, and moderate to severe heart failure that does not improve with optimal medical therapy. The study appeared in the Aug. 26 Circulation.

Data from 33,898 patients at 228 hospitals from January 2005 through September 2007 revealed that only 4.8% of patients with a left ventricular ejection fraction of 35% or less left the hospital with a new CRT implant, and 10% of those who did receive an implant had left ventricular ejection fractions higher than 35%. Patients treated in the northeastern U.S., black patients and older patients were among the groups least likely to receive the therapy.

Silver-coated endotracheal tubes may reduce risk for VAP, study finds

Endotracheal tubes coated with silver may help reduce rates of ventilator-associated pneumonia (VAP) in critically ill patients, according to a new study.

Researchers from the North American Silver-Coated Endotracheal Tube (NASCENT) Investigation Group performed a randomized, single-blind controlled trial to see whether patients who received mechanical ventilation using endotracheal tubes coated with silver were less likely to develop VAP. The primary outcome measure was VAP incidence in patients who needed ventilation for at least 24 hours. The study, funded by the silver-coated tube's manufacturer, was in the Aug. 20 Journal of the American Medical Association.

Of 1,509 patients who required ventilation for at least 24 hours, 4.8% in the silver-coated group and 7.5% in the uncoated group developed microbiologically confirmed VAP. Among all intubated patients (n=1,932), the corresponding percentages were 3.8% and 5.8%. The groups did not differ in length of intubation or ICU and hospital stay, adverse events or mortality rates.

The authors acknowledged several limitations of their study, including the overall low VAP rate, single-blind design and higher rate of chronic obstructive pulmonary disease (COPD) in the uncoated group. Still, the silver-coated endotracheal tube safely decreased microbiologically confirmed VAP in their study population, without requiring extra work on the part of clinicians, they wrote. An editorialist praised elements of the trial, but felt that silver-coated tubes shouldn't be seen as the definitive answer for VAP prevention, and should be used only in high-risk patients in ICUs where VAP prevention strategies fall short of institutional goals.

Guidelines updated for infective endocarditis prophylaxis in valvular heart disease

The American College of Cardiology and American Heart Association have updated their joint guidelines for preventing infective endocarditis (IE) in valvular heart disease.The update, published in the Aug. 19 Journal of the American College of Cardiology, is based on new evidence that has emerged since the 2006 ACC/AHA Guidelines for the Management of Valvular Heart Disease were published.

Major changes include: There are now no Class I recommendations for IE prophylaxis in patients with valvular heart disease; Antibiotic IE prophylaxis is no longer indicated in patients with aortic stenosis, mitral stenosis, or symptomatic or asymptomatic mitral valve prolapse. It is also not indicated in adolescents and young adults with native heart valve disease; It's not recommended to administer antibiotics solely to prevent IE in patients undergoing a genitourinary (GU) and gastrointestinal (GI) tract procedure. Nor is it recommended solely on the basis of an increased lifetime risk of IE; and IE prophylaxis for dental procedures should only be used in patients with underlying cardiac conditions associated with the highest risk for adverse outcomes, such as prosthetic valves or prior IE. In those cases, prophylaxis is reasonable for procedures that involve manipulating gingival tissue or the periapical region of teeth, or perforating oral mucosa.

Hospitalists should be prepared to discuss the updated guidelines with patients as the changes may cause some concern, the article said. Some doctors and patients may still be more comfortable continuing with prophylaxis for IE in certain circumstances; in those cases, the doctor should ensure that the risks associated with antibiotics are minor before prescribing them.

Take steps to prevent fractures in elderly before discharge, study suggests

Elderly patients often have a higher risk of fracture following hospitalization, presenting an opportunity for hospitals to take preventive steps before discharge, a recent study found.

In the prospective study, researchers analyzed the medical records of 3,075 white and black men and women age 70 to 79 years who were hospitalized between 1997-1998. After an almost seven-year follow-up period, 66% of the patients were admitted to a hospital and 26% were admitted three or more times. Risk of fracture increased with the number of times a patient had been admitted to the hospital, with those admitted three or more times having a 3.66-fold increased relative hazard for hip fracture.

Because the risk of fracture is greatest soon after discharge, the hospital stay is a good time to evaluate fracture risk by measurement of bone mineral density, assessment of fall risk, and initiation of treatments to reduce bone loss. The authors recommended that hospitals develop guidelines for assessing and reducing risk of fracture in this population.

Treating vitamin D deficiency to decrease bone loss, increase muscle strength and improve coordination should be incorporated into the care and discharge process for older adults, the authors noted. The study was published in the Aug. 11/25 Archives of Internal Medicine.

Rapid HIV test may show more false positives than traditional tests

Many patients who test positive from a rapid HIV test in the emergency department are later found to be negative when traditional tests are used, a new study found.

In the study, 849 adults underwent HIV testing with the rapid test when they visited an emergency department for another reason. Of these, 39 tested positive. Yet only five of the 39 were shown to actually have HIV infection after traditional testing was done. Twenty-six of the 39 were negative, and eight refused traditional testing. The study was published in the August 2008 issue of the Annals of Internal Medicine.

In 2006, the Centers for Disease Control and Prevention (CDC) recommended that all persons aged 13 to 64 be offered HIV screening in health care settings. Based on the current study, the authors said that quick and more reliable methods of testing are needed in the ER.