Primum non nocere and challenging conventional treatment

Pantoprazole or Placebo for Stress Ulcer Prophylaxis (POP-UP): Randomized Double-Blind Exploratory Study

OBJECTIVES

Pantoprazole is frequently administered to critically ill patients for prophylaxis against gastrointestinal bleeding. However, comparison to placebo has been inadequately evaluated, and pantoprazole has the potential to cause harm. Our objective was to evaluate benefit or harm associated with pantoprazole administration.

DESIGN

Prospective randomized double-blind parallel-group study.

SETTING

University-affiliated mixed medical-surgical ICU.

PATIENTS

Mechanically ventilated critically ill patients suitable for enteral nutrition.

INTERVENTIONS

We randomly assigned patients to receive either daily IV placebo or pantoprazole.

MEASUREMENTS AND MAIN RESULTS

Major outcomes were clinically significant gastrointestinal bleeding, infective ventilator-associated complication or pneumonia, and Clostridium difficile infection; minor outcomes included overt bleeding, hemoglobin concentration profiles, and mortality. None of the 214 patients randomized had an episode of clinically significant gastrointestinal bleeding, three patients met the criteria for either an infective ventilator-associated complication or pneumonia (placebo: 1 vs pantoprazole: 2), and one patient was diagnosed with Clostridium difficile infection (0 vs 1). Administration of pantoprazole was not associated with any difference in rates of overt bleeding (6 vs 3; p = 0.50) or daily hemoglobin concentrations when adjusted for transfusion rates of packed red cells (p = 0.66). Mortality was similar between groups (log-rank p = 0.33: adjusted hazard ratio for pantoprazole: 1.68 [95% CI, 0.97-2.90]; p = 0.06).

CONCLUSIONS

We found no evidence of benefit or harm with the prophylactic administration of pantoprazole to mechanically ventilated critically ill patients anticipated to receive enteral nutrition. The practice of routine administration of acid-suppressive drugs to critically ill patients for stress ulcer prophylaxis warrants further evaluation.

Occult upper gastrointestinal mucosal abnormalities in critically ill patients

BACKGROUND

The objectives of this study were to estimate the frequency of occult upper gastrointestinal abnormalities, presence of gastric acid as a contributing factor, and associations with clinical outcomes.

METHODS

Data were extracted for study participants at a single centre who had an endoscopy performed purely for research purposes and in whom treating physicians were not suspecting gastrointestinal bleeding. Endoscopic data were independently adjudicated by two gastroenterologists who rated the likelihood that observed pathological abnormalities were related to gastric acid secretion using a 3-point ordinal scale (unlikely, possible or probable).

RESULTS

Endoscopy reports were extracted for 74 patients [age 52 (37, 65) years] undergoing endoscopy on day 5 [3, 9] of ICU admission. Abnormalities were found in 25 (34%) subjects: gastritis/erosions in 10 (14%), nasogastric tube trauma in 8 (11%), oesophagitis in 4 (5%) and non-bleeding duodenal ulceration in 3 (4%). The contribution of acid secretion to observed pathology was rated 'probable' in six subjects (rater #1) and five subjects (rater #2). Prior to endoscopy, 39 (53%) patients were receiving acid-suppressive therapy. The use of acid-suppressive therapy was not associated with the presence of an endoscopic abnormality (present 15/25 (60%) vs. absent 24/49 (49%); P = 0.46). Haemoglobin concentrations, packed red cells transfused and mortality were not associated with mucosal abnormalities (P = 0.83, P > 0.9 and P > 0.9 respectively).

CONCLUSIONS

Occult mucosal abnormalities were observed in one-third of subjects. The presence of mucosal abnormalities appeared to be independent of prior acid-suppressive therapy and was not associated with reduced haemoglobin concentrations, increased transfusion requirements, or mortality.

Event-rate and delta inflation when evaluating mortality as a primary outcome from randomized controlled trials of nutritional interventions during critical illness: a systematic review

BACKGROUND

There is a lack of high-quality evidence that proves that nutritional interventions during critical illness reduce mortality.

OBJECTIVES

We evaluated whether power calculations for randomized controlled trials (RCTs) of nutritional interventions that used mortality as the primary outcome were realistic, and whether overestimation was systematic in the studies identified to determine whether this was due to overestimates of event rate or delta.

DESIGN

A systematic review of the literature between 2005 and 2015 was performed to identify RCTs of nutritional interventions administered to critically ill adults that had mortality as the primary outcome. Predicted event rate (predicted mortality during the control), predicted mortality during intervention, predicted delta (predicted difference between mortality during the control and intervention), actual event rate (observed mortality during control), observed mortality during intervention, and actual delta (difference between observed mortality during the control and intervention) were recorded. The event-rate gap (predicted event rate minus observed event rate), the delta gap (predicted delta minus observed delta), and the predicted number needed to treat were calculated. Data are shown as median (range).

RESULTS

Fourteen articles were extracted, with power calculations provided for 10 studies. The predicted event rate was 29.9% (20.0–52.4%), and the predicted delta was 7.9% (3.0–20.0%). If the study hypothesis was proven correct then, on the basis of the power calculations, the number needed to treat would have been 12.7 (5.0–33.3) patients. The actual event rate was 25.3% (6.1–50.0%), the observed mortality during the intervention was 24.4% (6.3–39.7%), and the actual delta was 0.5% (−10.2–10.3%), such that the event-rate gap was 2.6% (−3.9–23.7%) and delta gap was 7.5% (3.2–25.2%).

CONCLUSIONS

Overestimates of delta occur frequently in RCTs of nutritional interventions in the critically ill that are powered to determine a mortality benefit. Delta inflation may explain the number of "negative" studies in this field of research.