Recent Research

Influenza vaccination in hospitalized surgical patients, echocardiography use, outcomes in older patients after ED discharge, and more.


Influenza vaccination appears safe in hospitalized surgical patients

Vaccination for influenza does not appear to increase risk for adverse outcomes in hospitalized surgical patients, according to a recent study.

Researchers performed a retrospective cohort study using data from Kaiser Permanente Southern California to determine whether vaccinating inpatients during the perioperative period increased health care utilization or evaluation for postsurgical infections after hospital discharge. Patients who were admitted and discharged for surgery between Sept. 1 and March 31 from 2010-2013 and who were 6 months of age and older were included. The study examined all influenza vaccinations administered in the 2010-2011, 2011-2012, and 2012-2013 influenza seasons between Aug. 1 and April 30.

Outcome measures were rates of outpatient visits, readmission, ED visits, fever (defined as a temperature ≥38 °C), and clinical laboratory evaluations for infection (i.e., urine culture, complete blood count, blood culture, and wound culture) within 7 days after discharge. The study results were published online March 15 by Annals of Internal Medicine.

Overall, 81,647 surgeries in 78,392 patients were included in the study. Mean patient age was 56.5 years, and 58% were women. Most patients vaccinated between hospital admission and discharge were vaccinated on the day of discharge. In unadjusted analyses, vaccination was associated with elevated risk for all outcomes. In adjusted analyses, 42,777 surgeries were included, and in 6,420 of these, influenza vaccine was administered. Risk for inpatient visits (rate ratio [RR], 1.12; 95% CI, 0.96 to 1.32), ED visits (RR, 1.07; 95% CI, 0.96 to 1.20), postdischarge fever (RR, 1.00; 95% CI, 0.76 to 1.31), and clinical evaluations for infection (RR, 1.06; 95% CI, 0.99 to 1.13) did not differ between vaccinated and unvaccinated groups in adjusted analyses, although vaccinated patients continued to have a marginal increase in risk for outpatient visits (RR, 1.05; 95% CI, 1.00 to 1.10; P=0.032).

The authors noted that they did not make a distinction between planned and unplanned readmissions or outpatient visits and that risk was evaluated in the postdischarge period regardless of when patients were vaccinated during their hospitalization, among other limitations. However, they concluded that influenza vaccination during hospitalization appeared to increase only risk for outpatient visits after discharge and that this minimal risk should be considered against vaccination's benefits. Their study, along with others that have demonstrated success of hospital-based strategies to promote vaccination, can “inform strategies to improve vaccination rates where needed,” they wrote.

Echo underused, associated with lower inpatient mortality, study finds

Echocardiography may be underused in the care of hospitalized patients, and when used, it may be associated with lower inpatient mortality, according to a recent national analysis.

Researchers looked at data from the Nationwide Inpatient Sample to examine use of echocardiography for the 6 admission diagnoses for which it is most commonly used. Overall, between 2001 and 2011, the absolute volume of inpatient echo use steadily increased at an average annual rate of 3.41%. Results were published in the Feb. 9 Journal of the American College of Cardiology.

In 5 of the 6 studied diagnoses, use of echo was associated with lower risk of inpatient mortality, according to 2010 data. The adjusted odds ratio was 0.74 for patients with acute myocardial infarction (95% CI, 0.63 to 0.86), 0.72 for patients with cardiac dysrhythmia (95% CI, 0.55 to 0.94), 0.36 for patients with acute cerebrovascular disease (95% CI, 0.31 to 0.42), 0.82 for patients with congestive heart failure (95% CI, 0.72 to 0.94), and 0.77 for patients with sepsis (95% CI, 0.70 to 0.85). However, only a minority of patients (8%) with any of these conditions received echocardiography, the study found.

Based on the results, the authors concluded that echo may be underused during critical cardiovascular hospitalizations. The study doesn't prove a causal link between use of echo and lower mortality, but “we believe that the association observed here is the product of information provided by echo that assists physicians in management decisions and patient risk stratification,” the authors wrote, adding that the low use of echo might be due to clinicians', hospitals', or insurers' efforts to reduce inpatient costs. They noted that the study was limited by the use of administrative data, so that echocardiography might have been performed but not reported.

The study's findings are counterintuitive and “debunk the widespread perception of echocardiography overuse,” said an accompanying editorial. Although handheld devices are becoming increasingly popular, they do not provide the same benefits as complete transthoracic echocardiography, which this study suggests is underused in the conditions where it has most proven value, the editorial said.

Study identifies factors to predict poor outcomes in older patients discharged from the ED

Among older patients who were discharged from the ED, certain factors were associated with death or ICU admission in the following week, a recent study found.

Researchers randomly selected 300 visit records of patients older than age 65 years who were discharged from 1 of 13 EDs belonging to Kaiser Permanente Southern California and died or were admitted to the ICU within the following week. They were compared to 300 matched controls who were also discharged from the EDs but did not die or return to the ICU during follow-up. Results were published by Annals of Emergency Medicine on March 2.

The study found 4 characteristics associated with death or ICU admission within 7 days: cognitive impairment (adjusted odds ratio [AOR], 2.10; 95% CI, 1.19 to 3.56), a change in the disposition plan from admit to discharge (AOR, 2.71; 95% CI, 1.50 to 4.89), systolic blood pressure less than 120 mm Hg (AOR, 1.48; 95% CI, 1.00 to 2.20), and pulse greater than 90 beats/min (AOR, 1.66; 95% CI, 1.02 to 2.71).

The results reaffirm the importance of vital signs, said the study authors, suggesting that patients with low blood pressure or high pulse warrant further scrutiny before ED discharge. The association with cognitive impairment could be due to these patients not understanding discharge instructions or medication changes, but it could also be that ED clinicians are not sufficiently screening for and acting on cognitive impairment among their patients, the authors speculated.

They noted that change in a disposition plan could be the decision of a treating clinician or could be due to a patient leaving against medical advice, which has been previously associated with poor outcomes. However, the study also found that changes in disposition were associated with specialty consultations (which 28% of studied patients required). “Although the services of consultants are important, our findings suggest that ED provider decisions should not be based solely on consultant recommendations and should include the ED providers' intuition as well,” the authors wrote. They called for greater scrutiny and caution before ED discharge of patients with the observed characteristics.

Several antimicrobial stewardship components improve outcomes, review finds

Several components of antimicrobial stewardship programs appear to show benefits in terms of patient- and hospital-level outcomes, according to a recent systematic review and meta-analysis.

Using 145 unique studies, researchers assessed the effects of 9 antimicrobial stewardship objectives on 4 outcome measures: clinical outcomes (e.g., patient mortality and length of stay), adverse events, costs, and bacterial resistance rates. Results were published online on March 2 by The Lancet Infectious Diseases.

Researchers found that the following objectives led to significant benefits for at least 1 outcome: empirical therapy according to guidelines, de-escalation of therapy, switch from intravenous to oral treatment, therapeutic drug monitoring, use of a list of restricted antibiotics, and bedside consultation.

Notably, adherence to guidelines and de-escalation of therapy significantly decreased mortality (relative risk reductions, 35% and 66%, respectively; P<0.0001 for both). And although the overall effect of bedside consultation on mortality was not significant, a sensitivity analysis for patients with Staphylococcus aureus bacteremia showed a relative risk reduction of 66% (P=0.008).

“Although we assessed objectives separately, in practice, interventions are generally bundled, and the combined effect of meeting several objectives could be greater than that of meeting one.... Our results, combined with the critical appraisal of restrictive and persuasive strategies to improve appropriate antimicrobial use, might guide stewardship teams in their efforts to improve the quality of antibiotic use in hospitals,” the study authors wrote.

They noted limitations of their work, such as how the quality of evidence was generally low, with substantial heterogeneity between studies. They added that the included studies were published between 1979 and 2014, which could mean that not all results are applicable today.

“While the data on which their findings are based are far from ideal, interventions that encourage adherence to guidelines and de-escalation of therapy, as appropriate, are likely to be good starting points for any healthcare system starting an antimicrobial stewardship programme,” said an accompanying editorial. To better assess which bundle of interventions can most effectively improve global outcomes, future research should take into account the timeline of prescribed antimicrobial therapy, the editorialists wrote.

High-dose atorvastatin may not reduce AKI after cardiac surgery

Short-term, high-dose perioperative atorvastatin treatment did not reduce the risk of acute kidney injury (AKI) among patients undergoing cardiac surgery compared with placebo, a study found.

Researchers conducted a randomized, double-blind, placebo-controlled trial of adult cardiac surgery patients from November 2009 to October 2014 at Vanderbilt University Medical Center in Nashville, Tenn. AKI was defined as an increase of 0.3 mg/dL in serum creatinine concentration within 48 hours of surgery (Acute Kidney Injury Network criteria).

Among 199 patients naive to statin treatment, 102 were randomly assigned to receive 80 mg of atorvastatin the day before surgery, 40 mg of atorvastatin the morning of surgery, and 40 mg of atorvastatin daily following surgery, and 97 patients were assigned to placebo. Among 416 patients already taking a statin prior to study enrollment, all continued taking the pre-enrollment statin until the day of surgery, and then 206 were randomly assigned 80 mg of atorvastatin the morning of surgery and 40 mg of atorvastatin the morning after, with 210 receiving placebo. This group resumed taking the previously prescribed statin on postoperative day 2.

Results were published by the Journal of the American Medical Association on March 1.

At a planned interim analysis, the data and safety monitoring board recommended stopping the study in statin-naive patients due to increased AKI among patients with chronic kidney disease (estimated glomerular filtration rate <60 mL/min/1.73 m2) receiving atorvastatin. The board later recommended stopping the entire trial for futility after 615 participants completed the intervention.

Among all 615 participants, AKI occurred in 64 of 308 (20.8%) in the atorvastatin group compared to 60 of 307 (19.5%) in the placebo group (relative risk [RR], 1.06; 95% CI, 0.78 to 1.46; P=0.75). Among the 199 patients naive to statin treatment, AKI occurred in 22 of 102 (21.6%) in the atorvastatin group compared to 13 of 97 (13.4%) in the placebo group (RR, 1.61; 95% CI, 0.86 to 3.01; P=0.15). Among the 416 patients already taking a statin, AKI occurred in 42 of 206 (20.4%) in the atorvastatin group compared to 47 of 210 (22.4%) in the placebo group (RR, 0.91; 95% CI, 0.63 to 1.32; P=0.63).

These results do not support the initiation of statin therapy to prevent AKI following cardiac surgery, the authors wrote. An accompanying editorial found that the study provides “important additional evidence for the notion that continuing perioperative statin therapy is likely safe, rational, easy, inexpensive, and perhaps slightly protective against AKI for patients undergoing cardiac surgery.” But, by contrast, it continued, “any use as nephroprotective agents in patients naive to statin treatment undergoing cardiac surgery should now be abandoned.”