In this episode I’ll:
- Discuss an article about stress ulcer prophylaxis in patients receiving enteral nutrition.
- Answer the drug information question “How long after giving a female patient with urinary retention tamsulosin should a trial without catheter be attempted?”
- Share a resource for understanding statistical significance versus the clinical importance of observed effect sizes.
Lead author: Hui-Bin Huang
Published in Critical Care January 2018
Stress ulcers were first described in 1969. Stress ulcers are thought to form due to hypoperfusion to the gastric mucosa associated with critical illness. Various factors including coagulopathy, history of peptic ulcer disease, and prolonged mechanical ventilation are thought to be associated with stress ulcer formation.
In 1999, ASHP published therapeutic guidelines on stress ulcer prophylaxis. These guidelines came with a long list of potential indications for stress ulcer prophylaxis in critically ill patients. Dozens of trials and meta-analyses have examined stress ulcer prophylaxis since the publication of the 1999 guidelines. An update to the guidelines has been anticipated for much of this decade, but publication has been delayed.
The authors of this study performed a meta-analysis of randomized controlled trials (RCTs) to evaluate the effect of pharmacologic SUP in enterally fed patients on stress-related GI bleeding and other clinical outcomes.
The authors included trials that were RCTs comparing pharmacologic SUP to either placebo or no prophylaxis in enterally fed patients in the ICU.
Seven studies representing almost 900 patients were included. There was no statistically significant difference in GI bleeding between groups. This finding was confirmed by further subgroup analyses and sensitivity analysis. In addition, SUP had no effect on overall mortality, Clostridium difficile infection, length of stay in the ICU, or duration of mechanical ventilation. However, SUP was associated with an increased risk of hospital-acquired pneumonia (RR 1.53; 95% CI, 1.04 to 2.27; p = 0.03).
The authors concluded:
Our results suggested that in patients receiving enteral feeding, pharmacologic SUP is not beneficial and combined interventions may even increase the risk of nosocomial pneumonia.
This meta-analysis provides a strong suggestion that patients receiving enteral nutrition do not have their risk of stress ulcer further reduced by adding an H2RA or PPI. All studies included in the meta-analysis were small with under 200 patients each. This could have led to an overestimation of effect size. I would like to see these results replicated in a larger patient cohort.
There is a recently completed small two center randomized double-blind, placebo-controlled trial at University of Louisville Hospital and Jewish Hospital listed in clinicaltrials.gov. Initial results indicate that there was no difference in GI bleeding rate between the pantoprazole and placebo groups.
Drug information question
Q: How long after giving a female patient with urinary retention tamsulosin should a trial without catheter be attempted?
A: Limited data suggests the trial without catheter can be attempted 6 hours after giving tamsulosin.
Nearly all of the evidence supporting the use of tamsulosin for successfully removing urinary catheters in patients with urinary retention is in men with BPH. One study from 2004 involved 11 healthy female patients in a functional urodynamic experiment. Baseline urethral pressure profiles were recorded, then 0.4 mg tamsulosin was given, and urethral pressure profiles were repeated at 6 hours.
There was a significant relaxing effect of tamsulosin on the resting urethral tone. Waiting 6 hours is also logical based on the pharmacodynamic profile of tamsulosin, where peak levels occur about 4-5 hours after ingestion.
The resource for this episode is the tutorial article in Anesthesia and Analgesia for understanding statistical significance versus the clinical importance of observed effect sizes. P values do not convey any information about the effect size or the clinical importance of the observed effect. The article reviews different effect size measures and describes how confidence intervals can be used to address not only the statistical significance but also the clinical significance of the observed effect or association. The article provides intuitive examples of concepts and interpretation of results and does not go too deep into mathematical theory or concepts.
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