Studies on bedside lung ultrasound, preoperative frailty screening, and more

Summaries from ACP Hospitalist Weekly.

Bedside lung ultrasound may help in diagnosing pneumonia

Lung ultrasound performed at the bedside may be useful for diagnosing pneumonia, according to a recent study.

Researchers performed a systematic review and meta-analysis to determine whether bedside lung ultrasound was an accurate method of diagnosing pneumonia in adults. Studies were included if they involved patients 18 years of age and older who had clinical suspicion of or clinically confirmed pneumonia and compared lung ultrasound with other diagnostic methods that included chest X-ray or CT. The researchers rated the quality of the included studies using the Quality Assessment of Diagnostic Accuracy Studies tool and estimated summary receiver-operating characteristic curves and performed a pooled estimation of diagnostic odds ratio in a bivariate random-effects analysis. Results were published in the February CHEST.

Sixteen studies involving 2,359 patients were included in the analysis. Most of the studies were cohort studies performed in Europe, and all were conducted between 2008 and 2015. The researchers found substantial heterogeneity in sensitivity and specificity for lung ultrasound, with ranges of approximately 80% to 90% and 70% to 80%, respectively. The area under the summary receiver-operating characteristic curve was estimated at 0.93. The diagnostic odds ratio was calculated to be 50 (95% CI, 21 to 120), the optimal cutpoint. Higher-quality studies showed a trend toward a higher area under the summary receiver-operating characteristic curve, suggesting a threshold effect, but the difference was not found to be significant.

The authors noted that the included studies had high clinical heterogeneity and that use of diagnostic techniques varied substantially. However, they concluded that their analysis suggests a potential valuable role for lung ultrasound in addition to other diagnostic data (e.g., laboratory results) for diagnosing pneumonia in adults. Potential advantages include its easy reproducibility, low cost, and lack of ionizing radiation, while disadvantages include limited value in some patients (e.g., those who are obese) and operator-dependent results.

Based on their findings, the authors supported an adjuvant role for lung ultrasound along with chest X-ray because the latter provides additional information on the airway, soft tissues, and bone structure. “Nevertheless,” they wrote, “it is possible that the implementation of lung ultrasonography helps to minimize the number of radiological examinations, which could also have a positive impact on patient and staff safety, optimizing the use of time and economic resources.”

Preoperative frailty screening may improve outcomes

Screening elderly patients for frailty before surgery may improve postsurgical outcomes by allowing targeted interventions, a new study indicates.

Researchers performed a prospective cohort study at a Veterans Affairs medical center from Oct. 1, 2007, to July 1, 2014, examining patients who presented for major elective noncardiac surgery and comparing outcomes in those who were screened for frailty and those who were not. Screening of all patients scheduled for elective surgery began in July 2011 with the Risk Analysis Index (RAI), a 14-item questionnaire with scores ranging from 0 to 80. The records of patients with an RAI score of 21 or greater were flagged for review by the chief of surgery or a designee, and based on the results, surgery, anesthesia, critical care, and palliative care clinicians were notified about patients' frailty and the associated risks. Perioperative plans were then modified accordingly as needed. The study's main outcome measure was postoperative mortality rate at 30, 180, and 365 days. Results were published in the March JAMA Surgery.

Overall, 9,153 patients had elective surgery during the study period, 5,275 before screening was implemented and 3,878 afterward. Approximately 93% of all patients were men, and approximately 80% were white. Mean age was 60.3 years. Overall 30-day mortality decreased from 1.6% before screening to 0.7% after screening (P<0.001), with the most improvement seen among patients who were identified as frail (12.2% before screening vs. 3.8% afterward; P<0.001). The magnitude of improvement among frail patients increased at 180 days (23.9% to 7.7%; P<0.001) and 365 days (34.5% to 11.7% afterward; P<0.001). Multivariable models that controlled for age, frailty, and predicted mortality found that survival improved after the screening protocol was implemented (adjusted odds ratio for 180-day survival, 2.87; 95% CI, 1.98 to 4.16).

The authors noted that they may have included patients who screened as frail but did not have surgery, which may have introduced selection bias, and that their ability to determine a causal relationship between the intervention and improved outcomes was limited. In addition, they pointed out that their findings may not be generalizable and that surviving patients' quality of life after surgery is not known. However, they concluded that based on their results, facility-wide implementation of a frailty screening initiative is feasible and is associated with improved survival. Patients identified as frail before surgery can be targeted for several potentially effective interventions to improve outcomes, including prehabilitation, patient-centered decision making, and rescue therapy, the authors said. “The sustainability of [a frailty screening initiative] in the long term and implementation in different settings will depend on integration with clinical workflow, use of electronic medical records, and standardization of intervention for frail patients,” they wrote.

The authors of an accompanying invited commentary acknowledged the study's limitations, noting that alleviation of pain and symptoms may sometimes be more important than 1-year mortality and that patients' preoperative treatment preferences may become unrealistic postoperatively. Despite this, however, they said that “the time is now” for routine incorporation of frailty screening into preoperative assessment of elderly patients and for increased focus on patients' individual care goals.

Study supports SIRS as still useful sepsis indicator

Systemic inflammatory response syndrome (SIRS) remains a useful indicator of organ dysfunction and death despite its absence from Sepsis-3 criteria, according to a new study.

Researchers studied consecutive ED patients admitted to an Australian hospital with presumed infection over a three-year period (October 2007 to December 2008 and June 2009 to May 2011) and used observational data to calculate SIRS, quick Sepsis-Related Organ Failure Assessment (qSOFA), SOFA, comorbidity, and death. Sepsis-2 criteria include SIRS, while the Sepsis-3 criteria do not. The study authors noted that the new criteria use SOFA and qSOFA scores instead because of concerns that most patients with SIRS do not have infection and that some critical care patients with infection do not have SIRS. The goals of the current study were to examine the prognostic value of SIRS, compare the accuracy of SIRS and qSOFA for diagnosis of organ dysfunction, and compare Sepsis-2 and Sepsis-3 definitions of organ dysfunction. The study results were published in the March CHEST.

Overall, 8,871 patients were included in the study, and of these, 4,176 (47.1%) had SIRS. A total of 1,534 patients (17.3%) had acute organ dysfunction according to Sepsis-2 criteria, while a total of 2,166 (24.4%) had acute organ dysfunction according to Sepsis-3 criteria. SIRS was associated with increased risk of organ dysfunction as defined by Sepsis-2 and Sepsis-3 and increased odds of death in patients without organ dysfunction as defined by Sepsis-2 and Sepsis-3. Discrimination for organ dysfunction was similar for both SIRS and qSOFA, but while the latter also had high sensitivity for organ dysfunction (96.1%), its sensitivity was poor (29.7%).

Mortality was similar at 30 days and at one year regardless of whether organ dysfunction was defined by Sepsis-2 or Sepsis-3 criteria (12.5% and 11.4% at 30 days and 25.5% and 26.3% at one year, respectively). Of note, 29% of patients who had organ dysfunction according to Sepsis-3 criteria would not have met Sepsis-2 criteria for organ dysfunction. Increasing organ dysfunction according to Sepsis-2 criteria was associated with higher mortality rates.

The authors noted that their single-center study was observational, that they may not have identified all of the ED patients who were admitted with infection, and that some of the patients included in the study may not have had infection, among other limitations. However, they concluded that SIRS is associated with both organ dysfunction and mortality and “is a useful screening tool for organ dysfunction and death in ED patients with suspected infection.” Because SIRS appeared to have less effect on prognosis in patients with organ dysfunction and shock, however, it should not be used as an entry requirement in trials of severe sepsis and sepsis shock, the authors wrote.

A qSOFA score of 2 or greater was found to be highly specific for organ dysfunction, but the authors noted that its poor sensitivity may limit its usefulness as bedside assessment tool. In addition, they concluded that Sepsis-2 appears to convey more prognostic and clinical information on organ dysfunction than Sepsis-3 and that the SOFA score may need to be recalibrated for ED use, due to a wide variation in risk for death.

Survival better in patients on beta-blockers after PCI

Following successful percutaneous coronary intervention (PCI), a low dose of beta-blockers at discharge may confer survival benefit, particularly in patients with non-ST-segment elevation myocardial infarction (NSTEMI), according to a recent observational study.

In the analysis, researchers included 3,180 patients with acute coronary syndrome who underwent PCI at a single Chinese hospital. Overall, 2,423 patients (76.2%) were discharged on beta-blockers, and 757 (23.8%) were not. Results were published online Nov. 16 by the Journal of the American Heart Association.

The primary outcome was all-cause mortality, and the secondary outcome was a composite endpoint of all-cause death, nonfatal myocardial infarction (MI), heart failure readmission, and cardiogenic hospitalization. Follow-up information at one year was obtained for 3,153 patients (99.2%).

Overall, 33 patients died, 14 patients had nonfatal MI, 34 patients had heart failure, and 214 patients were readmitted for cardiogenic reasons. Compared with those who received beta-blockers, those who did not were older (P<0.001), had lower diastolic blood pressure (P=0.005), had lower heart rate (P=0.009), and were more likely to have arrhythmia (P=0.001).

Beta-blocker therapy was associated with a lower incidence of all-cause mortality (unadjusted hazard ratio, 0.33; 95% CI, 0.17 to 0.65; P=0.001). Mortality risk remained lower in the beta-blocker group than the non-beta-blocker group after adjustment for confounders (adjusted hazard ratio [HR], 0.38; 95% CI, 0.17 to 0.83; P=0.015) and propensity matching (HR, 0.27; 95% CI, 0.08 to 0.97; P=0.045).

Although a lower rate of the secondary endpoint was seen in beta-blocker users (unadjusted HR, 0.76; 95% CI, 0.59 to 0.98; P=0.035), the statistical difference disappeared after adjustment (adjusted HR, 0.87; 95% CI, 0.66 to 1.16; P=0.355).

At baseline, 728 patients (22.9%) had STEMI, 576 patients (18.1%) had NSTEMI, and 1,876 patients (59.0%) had unstable angina pectoris. In a subgroup analysis of only NSTEMI patients, all-cause death was lower in beta-blocker users than nonusers (0.2% vs. 6.4%; unadjusted HR, 0.04; 95% CI, 0.00 to 0.27; P=0.001). There were no significant differences between users and nonusers in subgroup analyses of patients with STEMI or unstable angina pectoris.

Researchers also assessed the effect of beta-blocker dose, defining target dose according to those used in large randomized trials. Overall, all-cause mortality was 0.7% in the group receiving less than 50% of the target dose compared to 2.1% in the group receiving no beta-blockers (adjusted HR, 0.40; 95% CI, 0.19 to 0.82; P=0.012). In contrast, the rate of all-cause mortality was not significantly different between those receiving 50% or more of the target dose and those receiving no beta-blockers (0.7% vs. 2.1%; adjusted HR, 0.46; 95% CI, 0.13 to 1.59; P=0.221).