Antibiotics for COPD, shock after MI, and more

Summaries from ACP Hospitalist Weekly.

Longer antibiotic therapy in patients with low procalcitonin during COPD exacerbation increased LOS without reducing readmissions

More than 24 hours of antibiotic therapy led to longer length of stay (LOS) without improving readmission rates in patients admitted with acute exacerbations of chronic obstructive pulmonary disease (COPD) who had low procalcitonin levels, a recent study found.

Researchers retrospectively evaluated 356 non-critically ill adults admitted with acute exacerbations of COPD who had peak procalcitonin concentrations of less than 0.25 µg/L. They split patients into two groups: those with 24 hours or fewer of antibiotic exposure (n=161) and those with more than 24 hours of antibiotic exposure (n=195). Researchers also assessed two groups of patients who received either 24 hours or fewer of azithromycin therapy or more than 24 hours of exposure to the antibiotic. In both analyses, the primary outcome was all-cause 30-day readmissions, and secondary outcomes included LOS and COPD-related 30-day readmissions. Results were published online on July 2 by Clinical Infectious Diseases.

Image by Getty Images
Image by Getty Images

The mean duration of antibiotic therapy was 5.5 days in the cohort that received more than 24 hours of antibiotic therapy, whereas 67% of patients in the group that received 24 hours or fewer of antibiotic therapy received no doses. The group with 24 hours or fewer of exposure to antibiotics had a shorter LOS than the group with more than 24 hours of exposure (2.8 d vs. 3.7 d; P<0.01). The rates of all-cause 30-day readmissions and COPD-related 30-day readmissions were not significantly different between the respective groups (15.5% vs. 17.4% [P=0.63] and 11.2% vs. 12.3% [P=0.74], respectively).

In the azithromycin subgroup analysis, 51% of patients who received 24 hours or fewer of therapy received no doses. Patients who received azithromycin for 24 hours or fewer had a shorter LOS compared to patients who received the drug for more than 24 hours (3.0 d vs. 3.8 d; P<0.01), and there were no significant differences between the respective groups in the rate of all-cause 30-day readmissions (16.2% vs. 17.1%; P=0.82) or COPD-related 30-day readmissions (11.9% vs. 11.6%; P=0.94).

The study authors noted limitations of the analysis, such as its retrospective nature and their inability to determine if undetected patient-specific factors played a role in the decision to prescribe antibiotic therapy in spite of low procalcitonin levels.

“We believe this study adds significant data to help antimicrobial stewardship programs curb antibiotic misuse for patients with [acute exacerbations of] COPD by utilizing [procalcitonin] as an objective biomarker to refrain from utilizing extended courses of antibiotics in clinically stable patients without elevated [procalcitonin] concentrations,” they concluded.

Epinephrine and norepinephrine compared to treat shock after myocardial infarction

For patients with cardiogenic shock after acute myocardial infarction, epinephrine was associated with similar effects on arterial pressure and cardiac index as norepinephrine but a higher incidence of refractory shock, a small study found.

The trial included 57 patients in France with cardiogenic shock after acute myocardial infarction. They were randomized into two study arms and received either epinephrine or norepinephrine. The primary efficacy outcome was cardiac index evolution, and the primary safety outcome was occurrence of refractory cardiogenic shock, which was defined as cardiogenic shock with sustained hypotension, end-organ hypoperfusion and hyperlactatemia, and high inotrope and vasopressor doses. Results were published by the Journal of the American College of Cardiology on July 2.

The primary efficacy endpoint was similar between the two groups (P=0.43) from baseline to 72 hours after treatment. However, the epinephrine group had a significantly higher rate of the main safety endpoint (10 of 27 [37%] vs. 2 of 30 [7%]; P=0.008). This finding led to early termination of the study. Heart rate was also increased with epinephrine from hour 2 to hour 24 (P<0.0001), as were cardiac double product (P=0.0002) and lactic acidosis (P<0.0001).

The study was done because epinephrine and norepinephrine are the most commonly used agents for cardiogenic shock, yet no prospective, randomized trial has compared their effects, the authors said. However, the trial was limited by its enrollment of only 57 patients over four years, possibly due to the absence of specialized heart teams and pulmonary artery catheters in many French hospitals.

“Despite premature termination of the trial and the relatively small treatment groups, we were able to identify a clinically meaningful difference in the number with refractory [cardiogenic shock] with epinephrine use compared with norepinephrine,” the authors said.

An accompanying editorial expressed less certainty about the clinical importance of the observed difference, noting that “there is no clear pathophysiological mechanism to explain why epinephrine is associated with refractory [cardiogenic shock].”

The editorialist did find that the study provides some clinically useful information about how the drugs, despite similar effects overall, may perform differently in certain situations. Specifically, “epinephrine could be theoretically advantageous in patients with bradycardia but deleterious in patients with ischemia, pre-treatment tachycardia, or at a high risk of arrhythmias” and epinephrine may “confound the interpretation of lactate clearance as a marker of restoration of systemic perfusion,” the editorial said.

ACA coverage expansion decreased frequent ED use among Medicaid, uninsured patients

California patients with Medicaid coverage or without insurance were less likely to be frequent ED users after the Affordable Care Act (ACA) expanded coverage compared to the prior two-year period, a recent study found.

Using 2012 to 2015 data from California's Office of Statewide Health Planning and Development, researchers compared characteristics of the state's frequent ED users ages 18 to 64 years before (2012 and 2013) and after (2014 and 2015) implementation of several ACA provisions that expanded health care coverage. Frequent users were defined as patients with four or more ED visits in a single calendar year. Results were published June 4 by Health Affairs.

Image by Getty Images
Image by Getty Images

Under the ACA, the share of all ED patients covered by Medicaid increased from 21.5% to 37.6%, and the share of uninsured patients decreased from 26.9% to 13.2%. These changes were even more pronounced among frequent ED users, with the proportion covered by Medicaid increasing from 44.6% to 67.6% and the proportion of uninsured decreasing from 29.0% to 8.3%.

In the two years after coverage expansion, the number of ED users increased by 511,284 (7.7%) compared to the two years prior, and the number of ED visits increased by about 1.16 million (9.9%). The number of frequent ED users increased by 81,800 under the ACA, accounting for 8.5% of ED patients compared to 7.9% of ED patients in 2012 and 2013. Frequent ED users comprised 30.7% of all ED visits before and 31.6% of those after coverage expansions took effect.

However, after controlling for patient characteristics such as health status, primary insurance coverage source, and county of residence, researchers found that the odds of being a frequent ED user declined by 12% for Medicaid patients and by nearly 50% for uninsured patients. Patients with private insurance saw a slight increase in the odds of frequent ED use, although they had much lower baseline odds of frequent use. The largest predictors of frequent ED use were diagnosis of a mental health condition (odds ratio, 3.34; P<0.001) and diagnosis of a non-alcohol-related substance use disorder (odds ratio, 2.64; P<0.001).

The study authors noted limitations of the analysis, such as how the data were self-reported by hospitals, potentially introducing errors and omissions. They added that 12% of ED visits could not be linked to individual patients and that the results apply only to California, which runs the largest Medicaid program in the country. The authors noted that although some were concerned that frequent ED use would rise with expanded coverage, “Our results suggest that the opposite occurred.”

Hospital care quality more likely a factor in early versus late readmissions

Quality of hospital care is more likely to be a factor in admissions that occur less than a week after discharge than in those that occur later, a recent study indicated.

Researchers performed a prospective cohort study at 10 U.S. academic medical centers to examine whether timing of readmission in relation to discharge was linked to preventability. Readmissions within seven days of discharge (early readmissions) were compared with those between 8 to 30 days of discharge (late readmissions). Two physician adjudicators at each study site used a structured survey instrument to assess each readmission and determine whether it was preventable. The study results were published online May 1 by Annals of Internal Medicine and appeared in the June 5 issue.

The study involved 822 adults readmitted to the general medicine service. Overall, 27.9% of readmissions were judged to be preventable, and of these, 36.2% were early and 23.0% were late (median risk difference, 13.0 percentage points; interquartile range, 5.5 to 26.4 percentage points). When the researchers looked at the ideal location for an intervention that would prevent a readmission, hospitals performed better for early versus late readmissions (47.2% vs. 25.5%; median risk difference, 22.8 percentage points; interquartile range, 17.9 to 31.8 percentage points), while outpatient clinics (15.2% vs. 6.6%; median risk difference, 10.0 percentage points; interquartile range, 4.6 to 12.2 percentage points) and patients' homes (19.4% vs. 14.0%; median risk difference, 5.6 percentage points; interquartile range, −6.1 to 17.1 percentage points) performed better for late versus early readmissions.

The authors noted that the study did not include community hospitals or readmissions to nonstudy hospitals and that physician adjudicators were not blinded. However, they concluded that early readmissions were more likely to be preventable than late readmissions and were more likely to be caused by such factors as premature discharge and problems with physician decision making. Late readmissions, meanwhile, were more likely to be related to factors outside the hospital's direct control, such as inappropriate monitoring and management of symptoms after discharge.

“We believe it is time to change the model for patient outcomes after hospital discharge to one that recognizes shared accountability for readmissions along the entire spectrum of care,” the researchers wrote. “If this cannot be achieved in the short term, our findings suggest that a 7-day readmission window will more accurately capture preventable hospital admissions.”