Septic shock, C. diff, and more

Summaries from ACP Hospitalist Weekly.

Septic shock patients who received IV thiamine had faster lactate clearance, study finds

In patients with septic shock, receiving IV thiamine supplementation was associated with reduced time to lactate clearance and lower 28-day mortality rates, a recent study found.

The retrospective study included ICU patients at one tertiary academic medical center with a diagnosis of septic shock: 123 who had been treated with IV thiamine within 24 hours of hospital admission and 246 matched controls who hadn't received thiamine. The primary outcome was time to lactate clearance; secondary outcomes included 28-day mortality, acute kidney injury, need for renal replacement therapy, and vasopressor and mechanical ventilation-free days. Results were published online by Critical Care Medicine on July 18, 2018, and appeared in the November 2018 issue.

Using the Fine-Gray survival model, the study found that treatment with thiamine was associated with an improved likelihood of lactate clearance (subdistribution hazard ratio, 1.307; 95% CI, 1.002 to 1.704) and a reduction in 28-day mortality (hazard ratio, 0.666; 95% CI, 0.490 to 0.905). There were no differences in the secondary outcomes.

The results are in accordance with previous research finding benefits to thiamine supplementation in patients with laboratory-confirmed deficiencies, the authors said. Thiamine testing can take a long time, however, and patients with sepsis may have increased risk for deficiency due to mitochondrial oxidative stress, decreased nutritional intake, or comorbid conditions, they added. “Thiamine is a particularly safe and inexpensive therapy, and although it remains an investigational agent for septic shock, now deserves a larger clinical trial to confirm these findings,” the authors wrote.

Limitations of the study include that prescription of thiamine was not randomized. The study population also included a large number of patients with cirrhosis, and the dose of thiamine was higher than in previous studies of the supplement in septic shock (500 mg IV every eight hours for 72 hours).

High inpatient occupancy levels associated with lower risk of hospital-acquired C. diff

Patients admitted on a day with high levels of hospital occupancy have a lower likelihood of hospital-acquired Clostridium difficile infection than those admitted on a day with low or intermediate occupancy levels, according to a recent study.

Researchers analyzed administrative data from 2008 to 2012 among Medicare recipients with a discharge diagnosis of acute myocardial infarction, heart failure, or pneumonia at 327 California hospitals. Using daily census data, they estimated the relationship between hospital occupancy during hospitalization (range, 0 to 1; four groups) and hospital-acquired C. difficile infection. Results were published online on June 27, 2018, by the Journal of Hospital Medicine and appeared in the October 2018 issue.

Image by Getty Images
Image by Getty Images

A total of 558,344 discharges were included in the analysis. Higher admission-day occupancy was associated with significantly lower adjusted odds of C. difficile infection. Compared to the 0 to 0.25 occupancy group, patients admitted on a day of 0.51 to 0.75 occupancy had 0.86 odds of C. difficile infection (95% CI, 0.75 to 0.98), and those admitted on a day of 0.76 to 1.00 occupancy had 0.87 odds of C. difficile infection (95% CI, 0.75 to 1.01).

Over the course of hospitalization, groups with intermediate levels of average occupancy had more than a threefold increased adjusted odds of C. difficile infection compared to the 0 to 0.25 occupancy group (odds ratios, 3.04 [95% CI, 2.33 to 3.96] for the 0.26 to 0.50 group and 3.28 [95% CI, 2.51 to 4.28] for the 0.51 to 0.75 group). The high occupancy group, however, did not have significantly different odds of C. difficile infection relative to the low occupancy group (odds ratio, 0.96; 95% CI, 0.70 to 1.31).

The inverse relationship between C. difficile infection and admission occupancy was contrary to the authors' expectations. “These findings suggest that an exploration of the processes associated with hospitals accommodating higher occupancy might elucidate measures to reduce [C. difficile infection],” they said, noting variations in staffing, policies, practices, and procedures during different stages of occupancy.

The authors noted limitations of the study, such as its focus on one state and potential inaccuracies in coding and data. “These findings should prompt exploration of how hospitals react to occupancy changes and how those care processes translate into [hospital-acquired conditions] in order to inform best practices for hospital care,” they wrote.

Many cellulitis hospitalizations may be unnecessary, study finds

Mortality rates for patients hospitalized for cellulitis are low, comparable to rates for low-risk patients with community-acquired pneumonia, a meta-analysis found.

To determine the mortality rate of patients hospitalized with cellulitis and compare it to that of low-risk patients with community-acquired pneumonia, researchers conducted a meta-analysis of studies of consecutive patients hospitalized with cellulitis or erysipelas that reported inpatient mortality. Eighteen studies met the inclusion criteria. Results were published July 18, 2018, by the Journal of General Internal Medicine.

The overall worldwide mortality rate for hospitalized patients with cellulitis in the included studies was 1.1% (95% CI, 0.7% to 1.8%). In individual studies, the mortality rate ranged from 0% to 2.9%. In studies from the U.S., the mortality rate was significantly lower, at 0.5% (95% CI, 0.3% to 0.9%). Overall, there was statistically significant evidence for heterogeneity (I2=98%, P<0.001). The actual cause of death in the studies was usually poorly described, and only about one-third of mortality appeared to be attributable to infection, the authors wrote.

The mortality rates found in this study are comparable to rates for patients who have community-acquired pneumonia that is mild enough for outpatient management, as recommended by prediction models and medical specialty societies, the authors said. Observation admission for low-acuity conditions such as cellulitis could save individual patients $1,500, individual hospitals $4.5 million, and the U.S. $3.1 billion, they calculated. In addition, available antibiotics can now be administered once weekly on an outpatient basis.

“If confirmed by a randomized controlled trial, outpatient management of patients currently being hospitalized for cellulitis could result in large cost savings to patients and payers and may be much preferred by patients,” the authors wrote.

Long-term survival from in-hospital cardiac arrest lower in black patients

Compared to white patients, black patients who had an in-hospital cardiac arrest (IHCA) were less likely to be alive one, three, or five years after discharge, a registry study found.

Image by Getty Images
Image by Getty Images

The study included data on 8,746 patients ages 65 years or older who had an IHCA at a hospital participating in the Get With The Guidelines-Resuscitation registry between 2000 and 2011 and survived until hospital discharge. Of the studied patients, 87.3% were white and 12.7% were black. Black patients with IHCA were younger and were more frequently female, had more comorbidities, were less likely to have a shockable initial cardiac arrest rhythm, and were less likely to receive coronary angiography after initial resuscitation. Black patients were also more likely to have at least moderate neurological disability at discharge and less likely to be discharged home. Results were published by Circulation on July 9, 2018.

After adjustment for hospital site, black patients had lower survival at one year (43.6% vs. 60.2%; relative risk [RR], 0.72), three years (31.6% vs. 45.3%; RR, 0.71), and five years (23.5% vs. 35.4%; RR, 0.67; P<0.001 for all comparisons). These racial differences were only partly eliminated by adjustment for additional factors: Patient factors explained 29% of the gap in one-year survival, and adjustment for hospital treatment factors explained an additional 17%. Patient and hospital factors explained similar proportions of the racial differences in three-year and five-year survival.

This leaves about half of the apparent racial disparity unexplained, the authors noted. This is a bigger gap than that seen for some other causes of hospitalization, such as heart failure, which may suggest that, in IHCA, “the quality and availability of postacute care matter more than they do for other conditions,” the authors said. They called for research into whether disparities in postacute care are responsible for the observed differences in survival and “whether interventions can be developed to eliminate racial disparities in care and survival for cardiac arrest survivors.”

Closed-loop systems may improve inpatient glycemic control over subcutaneous insulin delivery

For noncritical care inpatients with type 2 diabetes who require insulin therapy, closed-loop delivery may lead to better glycemic control than subcutaneous delivery without increasing the risk of hypoglycemia, a recent trial found.

Researchers conducted a randomized, open-label trial on general wards of two tertiary care hospitals in the U.K. and Switzerland. They assigned 136 adults with type 2 diabetes to receive either fully automated closed-loop delivery (n=70) or conventional subcutaneous therapy (n=66). The primary endpoint was the percentage of time that the sensor glucose measurement was within the target range of 100 to 180 mg/dL (5.6 to 10.0 mmol/L) for up to 15 days or until discharge. Results were published online on June 25, 2018, by the New England Journal of Medicine and appeared in the Aug. 9, 2018, issue.

In the closed-loop group, the mean (±SD) percentage of time glucose measurements were in the target range was 65.8% (±16.8%), compared to 41.5% (±16.9%) in the control group, a difference of 24.3 (±2.9) percentage points (95% CI, 18.6 to 30.0; P<0.001). The mean sensor glucose measurement was 154 mg/dL (8.5 mmol/L) in the closed-loop group, compared to 188 mg/dL (10.3 mmol/L) in the control group (P<0.001). Above-target glucose values occurred in 23.6% (±16.6%) of patients in the closed-loop group, compared to 49.5% (±22.8%) of those in the control group, a difference of 25.9 (±3.4) percentage points (95% CI, 19.2 to 32.7; P<0.001).

There was no significant difference between groups in the duration of hypoglycemia (defined as a blood glucose level <54 mg/dL or <3 mmol/L) or in the amount of insulin delivered (median dose, 44.4 U in the closed-loop group vs. 40.2 U in the control group). No patients had severe hypoglycemia or clinically significant hyperglycemia with ketonemia.

The study authors noted limitations, such as how glucose measurements were more available in the closed-loop group and that the mean follow-up period was significantly longer in the closed-loop group than in the control group (7.9±3.9 d vs. 6.4±4.0 d, respectively; P=0.03).

They added that in the control group, any loss of connectivity between the sensor and the receiver device would not have been detected and could have contributed to the smaller amount of sensor glucose data.

The authors wrote that “further work is required to determine practical considerations, facilitate ease of use, and assess costs” of using the closed-loop system in clinical practice. “Before closed-loop systems can have widespread use, they may need to be integrated with electronic-record systems in hospitals and with training for health care professionals,” they said