Journal watch: Recent studies of note

Recent studies about hand-carried ultrasound devices, LDL levels, and other topics.


Hand-carried ultrasound devices help diagnostic accuracy

Hand-carried ultrasound devices may help hospitalists diagnose some cardiac conditions, a recent study showed.

Researchers studied 10 hospitalists at Johns Hopkins Bayview Medical Center to determine whether hand-carried ultrasound devices improved diagnostic accuracy compared with physical examination. After undergoing training, hospitalists examined patients first with physical examination only and then with the device. The hospitalists' assessments with and without the device were compared with an expert cardiologist's assessment, which was based on a hospital echocardiogram. The study appears in the January issue of the American Journal of Medicine.

Handheld ultrasound devices improved hospitalists' diagnostic accuracy for left ventricular dysfunction, cardiomegaly and pericardial effusion but not for aortic stenosis, aortic regurgitation or mitral regurgitation. In addition, hospitalists using the devices were more likely to overdiagnose the latter two conditions, probably because they involve interpretation of color Doppler.

The authors acknowledged that the study has important limitations, including assessment of only one level of ultrasound training and lack of assessment of cost-effectiveness or clinical impact. They concluded that while hand-carried ultrasound devices can improve hospitalists' diagnostic accuracy of certain cardiac conditions, their widespread use is not yet justified. Until clinical benefit has been proven, bedside use should be reserved for “clinically focused situations for which there is a proven informational benefit.”

LDL levels don't measure risk of heart disease hospitalizations

Many hospitalized coronary artery disease patients had low-density lipoprotein (LDL) levels that are not considered high-risk by current guidelines, a recent study found.

Using the Get with the Guidelines database, researchers analyzed 136,905 hospitalizations from 2000 to 2006 that had documented lipid levels within the first 24 hours of admission. Patients were divided into LDL, high-density lipoprotein (HDL) and triglyceride categories. About 54% had hypertension, 26% had diabetes and 30% were smokers, while 16.5% had prior myocardial infarction. Prior to admission, 21% of patients were on lipid-lowering medication. Admission diagnosis was most commonly related to acute coronary events.

Mean LDL was 104.9 ± 39.8 mg/dL, while mean HDL was 39.7 ± 13.2 mg/dL and mean triglycerides were 161 ± 128 mg/dL. Nearly half the hospitalized patients had an LDL of less than 100 mg/dL, which the National Cholesterol Education Program (NCEP) considers “optimal.” About 18% had LDL levels less than 70 mg/dL, which the NCEP considers an optional goal for high-risk patients. By contrast, fewer than 10% of patients had an optimal HDL level of 60 mg/dL or more. The article is in the January issue of American Heart Journal.

The results indicate that, although high LDL is considered a major risk factor for heart disease, a substantial portion of patients come to the hospital with coronary artery disease events with levels that are within guidelines, the study's authors said. The results support guideline revisions with lower LDL goals, and may also suggest a need to develop treatments to raise HDL, the authors said.

Glucose control suboptimal at U.S. academic medical centers

Academic medical centers in the U.S. could be doing more to provide optimal glucose control, according to a recent study.

Researchers performed a retrospective cohort study to determine how well glucose levels were managed at U.S. academic medical centers. Data from three consecutive days were analyzed in 1,718 patients discharged from 37 academic medical centers between July 1 and Sept. 30, 2004. The results appear in the January issue of the Journal of Hospital Medicine.

Preexisting diabetes was common in the study population (79%), as was in-hospital insulin use (84.6% of patients received insulin on day 2). Recommended assessment of glycosylated hemoglobin level and glucose level at admission varied widely among hospitals. Glucose control was better with IV insulin than with subcutaneous insulin, but only 50% of ICU patients had received it on day 1. More than 70% of patients who received subcutaneous insulin, meanwhile, had glucose levels higher than 180 mg/dL on days 1, 2, and 3, in contrast to the level of 180 mg/dL or less recommended by the American Diabetes Association. In addition, only 25% of patients classified as critically ill had 6:00 a.m. glucose levels less than 110 mg/dL on day 3. Severe hypoglycemia was seen in 2.8% of patient-days.

The study assessed a limited time period and its results do not necessarily apply to community-based medical centers, among other limitations. However, the authors concluded that glucose control in U.S. academic medical centers could be substantially improved through increased use of insulin protocols and more frequent measurement of hemoglobin A1c levels.

Health care-associated pneumonia requires aggressive treatment

In a study in the Jan. 6 issue of Annals of Internal Medicine, researchers sought to determine the epidemiology and outcome for patients with community-acquired, health care-associated or hospital- acquired pneumonia. During two one-week surveillance periods, researchers looked at 362 patients hospitalized with pneumonia. They collected information to identify patients with how their pneumonia was acquired. They then compared information on antibiotics used for treatment, severity of pneumonia, length of hospital stay, and death rates among the three groups.

Researchers found that patients with community-acquired pneumonia had the least complicated course, with the shortest hospital stays and the lowest death rates. Conversely, patients with hospital-acquired pneumonia had the most complicated cases, the longest hospital stays and the highest in-hospital death rates. Researchers concluded that health care-associated pneumonia is a more serious illness than community-acquired pneumonia with worse patient outcomes. They suggest that doctors carefully identify how patients contracted pneumonia, and administer the appropriate antibiotics for the type of pneumonia the patient has in accordance with established guidelines.

Diabetic regimens may need adjustment after bariatric surgery

Nearly 30% of patients who undergo bariatric surgery have type 2 diabetes, but it often resolves after the procedure because of changes to the hormones that control insulin secretion. Researchers reviewed available literature to determine how the various bariatric procedures affect glycemic control. Their results appear in the Jan. 20 issue of Annals of Internal Medicine.

The authors found that the effects on the enteroinsular axis vary with restrictive, malabsorptive and combined bariatric surgery procedures. Glucagon-like peptide levels and peptide YY levels increase after intestinal bypass procedures, while incretin or peptide YY levels do not increase after restrictive procedures. The researchers concluded that physicians must anticipate the rapid improvements in insulin action after bariatric surgery and adjust diabetic regimens accordingly to avoid severe postoperative hypoglycemia. Future research, they suggested, should focus on making postoperative medical management safer for patients receiving diabetes therapy.

Newer drug may offer sedation advantage in critically ill

Dexmedetomidine may be a better choice for sedation in critically ill patients than more commonly used agents, a recent study found.

Researchers from the SEDCOM (Safety and Efficacy of Dexmedetomidine Compared With Midazolam) Study Group performed a double-blind, randomized trial to determine whether dexmedetomidine offered efficacy and safety advantages when used to sedate critically ill patients on mechanical ventilation. The study was funded by Hospira, the manufacturer of dexmedetomidine. It was released early online Feb. 2 and appeared in the Feb. 4 Journal of the American Medical Association.

The study involved 68 ICUs in five countries and was conducted between March 2005 and August 2007. Eligible patients were those at least 18 years of age who had been receiving mechanical ventilation for less than 96 hours before the study drug was started and who were expected to be ventilated and sedated for at least three additional days. Two hundred forty-four patients received dexmedetomidine, and 122 received midazolam. The primary end point was the percentage of time spent in the ideal sedation range. Secondary end points included rates and duration of delirium, duration of mechanical ventilation, and length of ICU stay.

The primary outcome did not differ between the study groups. However, patients receiving the study drug were less likely to develop delirium (54% vs. 76.6%; P< 0.001) and had shorter duration of intubation (median time to extubation, 3.7 days vs. 5.6 days; P= 0.01). Patients receiving the study drug were more likely to develop bradycardia (42.2% vs. 18.9%; P< 0.001) but less likely to develop tachycardia (25.4% vs. 44.3%; P<; 0.001) or severe hypertension (18.9% vs. 29.5%; P= 0.02).

The study had several limitations, such as its lack of an “intent-to-treat-as-randomized” group. Although the authors didn't detect a difference between the tested drugs in achieving the desired sedation level, they concluded that dexmedetomidine improved time on the ventilator and delirium rates when compared with a more traditional sedating agent. An accompanying editorial noted that the secondary outcome of reduced delirium is an important finding. “Clinicians now have a widened choice of sedatives and should always consider not only the need for sedation but also the possible clinical implications of the choice of sedative,” the editorialists wrote.