Proton pump inhibitors for gastrointestinal bleeding prophylaxis in critically ill patients: A systematic review protocol

BACKGROUND

Proton pump inhibitors (PPIs) are the most commonly prescribed drugs for preventing upper gastrointestinal bleeding in critically ill patients. However, concerns have arisen about the possible harms of using PPIs, including potentially increased risk of pneumonia, Clostridioides difficile infection, and more seriously, an increased risk of death in the most severely ill patients. Triggered by the REVISE trial, which is a forthcoming large randomized trial comparing pantoprazole to placebo in invasively mechanically ventilated patients, we will conduct this systematic review to evaluate the efficacy and safety of PPIs versus no prophylaxis for critically ill patients.

METHODS

We will systematically search randomized trials that compared gastrointestinal bleeding prophylaxis with PPIs versus placebo or no prophylaxis in adults in the intensive care unit (ICU). Pairs of reviewers will independently screen the literature, and for those eligible trials, extract data and assess risk of bias. We will perform meta-analyses using a random-effects model, and calculate relative risks for dichotomous outcomes and mean differences for continuous outcomes, and the associated 95% confidence intervals. We will conduct subgroup analysis to explore whether the impact of PPIs on mortality differs in more and less severely ill patients. We will assess certainty of evidence using the GRADE approach.

DISCUSSION

This systematic review will provide the most up-to-date evidence regarding the merits and limitations of stress ulcer prophylaxis with PPIs in critically ill patients in contemporary practice.

Thrombocytopenia and platelet transfusions in ICU patients: an international inception cohort study (PLOT-ICU)

PURPOSE

Thrombocytopenia (platelet count < 150 × 109/L) is common in intensive care unit (ICU) patients and is likely associated with worse outcomes. In this study we present international contemporary data on thrombocytopenia in ICU patients.

METHODS

We conducted a prospective cohort study in adult ICU patients in 52 ICUs across 10 countries. We assessed frequencies of thrombocytopenia, use of platelet transfusions and clinical outcomes including mortality. We evaluated pre-selected potential risk factors for the development of thrombocytopenia during ICU stay and associations between thrombocytopenia at ICU admission and 90-day mortality using pre-specified logistic regression analyses.

RESULTS

We analysed 1166 ICU patients; the median age was 63 years and 39.5% were female. Overall, 43.2% (95% confidence interval (CI) 40.4-46.1) had thrombocytopenia; 23.4% (20-26) had thrombocytopenia at ICU admission, and 19.8% (17.6-22.2) developed thrombocytopenia during their ICU stay. Absence of acquired immune deficiency syndrome (AIDS), non-cancer-related immune deficiency, liver failure, male sex, septic shock, and bleeding at ICU admission were associated with the development of thrombocytopenia during ICU stay. Among patients with thrombocytopenia, 22.6% received platelet transfusion(s), and 64.3% of in-ICU transfusions were prophylactic. Patients with thrombocytopenia had higher occurrences of bleeding and death, fewer days alive without the use of life-support, and fewer days alive and out of hospital. Thrombocytopenia at ICU admission was associated with 90-day mortality (adjusted odds ratio 1.7; 95% CI 1.19-2.42).

CONCLUSION

Thrombocytopenia occurred in 43% of critically ill patients and was associated with worse outcomes including increased mortality. Platelet transfusions were given to 23% of patients with thrombocytopenia and most were prophylactic.

A survey of preferences for respiratory support in the intensive care unit for patients with acute hypoxaemic respiratory failure

BACKGROUND

When caring for mechanically ventilated adults with acute hypoxaemic respiratory failure (AHRF), clinicians are faced with an uncertain choice between ventilator modes allowing for spontaneous breaths or ventilation fully controlled by the ventilator. The preferences of clinicians managing such patients, and what motivates their choice of ventilator mode, are largely unknown. To better understand how clinicians' preferences may impact the choice of ventilatory support for patients with AHRF, we issued a survey to an international network of intensive care unit (ICU) researchers.

METHODS

We distributed an online survey with 32 broadly similar and interlinked questions on how clinicians prioritise spontaneous or controlled ventilation in invasively ventilated patients with AHRF of different severity, and which factors determine their choice.

RESULTS

The survey was distributed to 1337 recipients in 12 countries. Of these, 415 (31%) completed the survey either fully (52%) or partially (48%). Most respondents were identified as medical specialists (87%) or physicians in training (11%). Modes allowing for spontaneous ventilation were considered preferable in mild AHRF, with controlled ventilation considered as progressively more important in moderate and severe AHRF. Among respondents there was strong support (90%) for a randomised clinical trial comparing spontaneous with controlled ventilation in patients with moderate AHRF.

CONCLUSIONS

The responses from this international survey suggest that there is clinical equipoise for the preferred ventilator mode in patients with AHRF of moderate severity. We found strong support for a randomised trial comparing modes of ventilation in patients with moderate AHRF.

Long-term effects of restriction of intravenous fluid in adult ICU patients with septic shock

PURPOSE

To assess long-term outcomes of restrictive versus standard intravenous (IV) fluid therapy in adult intensive care unit (ICU) patients with septic shock included in the European Conservative versus Liberal Approach to Fluid Therapy in Septic Shock in Intensive Care (CLASSIC) trial.

METHODS

We conducted the pre-planned analyses of mortality, health-related quality of life (HRQoL) using EuroQol (EQ)-5D-5L index values and EQ visual analogue scale (VAS), and cognitive function using Mini Montreal Cognitive Assessment (Mini MoCA) test at 1 year. Deceased patients were assigned numerical zero for HRQoL as a state equal to death and zero for cognitive function outcomes as worst possible score, and we used multiple imputation for missing data on HRQoL and cognitive function.

RESULTS

Among 1554 randomized patients, we obtained 1-year data on mortality in 97.9% of patients, HRQoL in 91.3%, and cognitive function in 86.3%. One-year mortality was 385/746 (51.3%) in the restrictive-fluid group versus 383/767 (49.9%) in the standard-fluid group, absolute risk difference 1.5%-points [99% confidence interval (CI) - 4.8 to 7.8]. Mean differences were 0.00 (99% CI - 0.06 to 0.05) for EQ-5D-5L index values, - 0.65 for EQ VAS (- 5.40 to 4.08), and - 0.14 for Mini MoCA (- 1.59 to 1.14) for the restrictive-fluid group versus the standard-fluid group. The results for survivors only were similar in both groups.

CONCLUSIONS

Among adult ICU patients with septic shock, restrictive versus standard IV fluid therapy resulted in similar survival, HRQoL, and cognitive function at 1 year, but clinically important differences could not be ruled out.

Use of prokinetic agents in hospitalised adult patients: A scoping review

BACKGROUND

Gastrointestinal motility is important for adequate uptake of fluids and nutrition but is often impaired in hospitalised patients. Prokinetic agents enhance gastrointestinal motility and are prescribed for many hospitalised patients. In this scoping review, we aimed to systematically describe the body of evidence on the use of prokinetic agents in hospitalised patients. We hypothesised, that the body of evidence would be limited and derive from heterogeneous populations.

METHODS

We conducted this scoping review in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews statement. We searched Medline, Embase, Epistemonikos and the Cochrane Library for studies assessing the use of prokinetic agents on any indication and outcome in adult hospitalised patients. We used a modified version of the Grading of Recommendations Assessment, Development and Evaluation (GRADE) to assess the certainty of evidence.

RESULTS

We included 102 studies with a total of 8830 patients. Eighty-six studies were clinical trials (84%), and 52 (60%) of these were conducted in the intensive care unit, with feeding intolerance as the main indication. In the non-intensive care setting the indications were wider; most studies assessed use of prokinetic agents before gastroscopy to improve visualisation. The most studied prokinetic agent was metoclopramide (49% of studies) followed by erythromycin (31%). In total 147 outcomes were assessed with only 67% of the included studies assessing patient-centred outcomes, and with gastric emptying as the most frequently reported outcome. Overall, the data provided no firm evidence on the balance between the desirable and undesirable effects of prokinetic agents.

CONCLUSIONS

In this scoping review, we found that the studies addressing prokinetic agents in hospitalised adults had considerable variations in indications, drugs and outcomes assessed, and that the certainty of evidence was judged to be low to very low.

Associations between enteral nutrition and outcomes in the SUP-ICU trial: Protocol for exploratory post hoc analyses

Critically ill patients are at risk of gastrointestinal (GI) bleeding. Counter measures to minimise this risk include the use of pharmacological stress ulcer prophylaxis (SUP). The effect of enteral nutrition as SUP on GI bleeding event rates is unknown. There are conflicting data describing the effect of co-administration of enteral nutrition with pharmacological SUP, and there is substantial variation in practice. We aim to conduct an exploratory post hoc analysis to evaluate the association of enteral nutrition with clinically important GI bleed rates in ICU patients included in the SUP-ICU trial, and to explore any interactions between enteral nutrition and pharmacologic SUP on patient outcomes. The SUP-ICU trial dataset will be used to assess if enteral nutrition is associated with the outcomes of interest. Extended Cox models will be used considering relevant competing events, including treatment allocation (SUP or placebo) and enteral nutrition as a daily time-varying covariate, with additional adjustment for severity of illness (SAPS II). Results will be presented as adjusted hazard ratios for treatment allocation and enteral nutrition, and for treatment allocation and enteral nutrition considering potential interactions with the other variable, all with 95% confidence intervals and p-values for the tests of interaction. All results will be considered as exploratory only. This post hoc analysis may yield important insights to guide practice and inform the design of future randomised clinical trial investigating the effect of enteral nutrition on GI bleeding.

Use of vasoactive agents in non-cardiac surgery: Protocol for a scoping review

BACKGROUND

An increasing number of patients undergo surgical procedures worldwide each year, and despite advances in quality and care, morbidity and mortality rates remain high. Perioperative hypotension is a well-described condition, and is associated with adverse outcomes. Both fluids and vasoactive agents are commonly used to treat hypotension, however, whether one vasoactive agent is preferable over another has yet to be explored.

METHODS

In accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) statement, we plan to conduct a scoping review of studies assessing the use of vasoactive agents in patients undergoing non-cardiac surgery. We will provide an overview of indications, agents used and outcomes assessed. We will assess and report the certainty of evidence according to the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

RESULTS

We will provide descriptive analyses of the included studies accompanied by tabulated results.

CONCLUSION

The outlined scoping review will provide a summary of the body of evidence on the use of vasoactive agents in the non-cardiac surgical population.

Use of prokinetic agents in hospitalised adult patients: Protocol for a scoping review

Background

Gastrointestinal motility is an important contributor to the effective uptake of water and nutrition. However, it is often impaired in acutely ill hospitalised patients. Amongst other indications, prokinetic agents are used to improve GI motility, but the body of evidence is not well described. Accordingly, we aim to systematically describe and explore the body of evidence on the use of prokinetic agents in hospitalised adults.

Methods

In accordance with the Preferred Reporting Items for Systematic Reviews and Meta‐Analyses extension for Scoping Reviews statement, we plan to conduct a scoping review of studies assessing the use of prokinetic agents, for any indication, in hospitalised adults. We plan to assess study design, population, agents, indications and outcomes across included studies. When applicable, we plan to assess the certainty of evidence using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

Results

We plan to provide descriptive analyses of the included studies accompanied by tabulated results and characterise knowledge gaps.

Conclusion

The outlined scoping review will provide a summary of the body of evidence on the use, indications, effects and side effects of prokinetic agents in hospitalised adults.

Management of acute atrial fibrillation in the intensive care unit: An international survey

BACKGROUND

Atrial fibrillation (AF) is common in intensive care unit (ICU) patients and is associated with poor outcomes. Different management strategies exist, but the evidence is limited and derived from non-ICU patients. This international survey of ICU doctors evaluated the preferred management of acute AF in ICU patients.

METHOD

We conducted an international online survey of ICU doctors with 27 questions about the preferred management of acute AF in the ICU, including antiarrhythmic therapy in hemodynamically stable and unstable patients and use of anticoagulant therapy.

RESULTS

A total of 910 respondents from 70 ICUs in 14 countries participated in the survey with 24%-100% of doctors from sites responding. Most ICUs (80%) did not have a local guideline for the management of acute AF. The preferred first-line strategy for the management of hemodynamically stable patients with acute AF was observation (95% of respondents), rhythm control (3%), or rate control (2%). For hemodynamically unstable patients, the preferred strategy was observation (48%), rhythm control (48%), or rate control (4%). Overall, preferred antiarrhythmic interventions included amiodarone, direct current cardioversion, beta-blockers other than sotalol, and magnesium in that order. A total of 67% preferred using anticoagulant therapy in ICU patients with AF, among whom 61% preferred therapeutic dose anticoagulants and 39% prophylactic dose anticoagulants.

CONCLUSION

This international survey indicated considerable practice variation among ICU doctors in the clinical management of acute AF, including the overall management strategies and the use of antiarrhythmic interventions and anticoagulants.

Interactions in clinical trials: Protocol and statistical analysis plan for an explorative study of four randomized ICU trials on use of pantoprazole, oxygenation targets, haloperidol and intravenous fluids

BACKGROUND

Intensive care unit (ICU) patients receive numerous interventions, but knowledge about potential interactions between these interventions is limited. Co-enrolment in randomized clinical trials represents a unique opportunity to investigate any such interactions. We aim to assess interactions in four randomized clinical trials with overlap in inclusion periods and patient populations.

METHODS

This protocol and statistical analysis plan describes a secondary explorative analysis of interactions in four international ICU trials on pantoprazole, oxygenations targets, haloperidol and intravenous fluids, respectively. The primary outcome will be 90-day all-cause mortality. The secondary outcome will be days alive and out of hospital in 90 days after randomization. All patients included in the intention-to-treat populations of the four trials will be included. Four co-primary analyses will be conducted, one with each of the included trials as reference using a logistic regression model adjusted for the reference trial's stratification variables and for the co-interventions with interactions terms. The primary analytical measure of interest will be the analyses' tests of interaction. A p-value below .05 will be considered statically significant. The stratification variable- and co-intervention-adjusted effect estimates will be reported with 95% confidence intervals without adjustments for multiplicity.

CONCLUSION

This exploratory analysis will investigate the presence of any interactions between pantoprazole, oxygenation targets, haloperidol and amount of intravenous fluids in four international ICU trials using co-enrolment. Assessment of possible interactions represents valuable information to guide the design, statistical powering and conduct of future trials.

Predictors of gastrointestinal bleeding in adult ICU patients in the SUP-ICU trial

BACKGROUND

In previous studies of predictors of gastrointestinal (GI) bleeding in the intensive care unit (ICU), most patients received pharmacological stress ulcer prophylaxis (SUP). We aimed to assess associations between potential predictors of clinically important GI bleeding (CIB) and overt GI bleeding in adult ICU patients, while considering the effect and potential interaction with use of SUP.

METHODS

We included 3291 acutely admitted adult ICU patients with risk factors for GI bleeding randomized to SUP (pantoprazole) or placebo in the SUP-ICU trial. We used logistic regression models adjusted for allocation to SUP to estimate associations between 23 potential predictors and CIB (primary outcome) and overt GI bleeding (secondary outcome). Furthermore, we assessed associations between potential predictors and both outcomes in each allocation group and assessed potential interaction with allocation to SUP.

RESULTS

Increasing SAPS II and SOFA scores, use of circulatory support and renal replacement therapy were associated with increased risk of CIB and overt GI bleeding; chronic lung disease was associated with increased risk of overt GI bleeding. Results for the remaining potential predictors were compatible with both no difference or increased and decreased risks. We found no strong evidence for any interaction between treatment allocation and any potential predictors.

CONCLUSION

In adult ICU patients at risk of GI bleeding, severity of illness, use of circulatory support and renal replacement therapy were associated with higher odds of CIB, with no strong evidence of interaction with SUP.

Prophylactic use of acid suppressants in adult acutely ill hospitalised patients: A systematic review with meta-analysis and trial sequential analysis

BACKGROUND

Acutely ill patients are at risk of stress-related gastrointestinal (GI) bleeding and prophylactic acid suppressants are frequently used. In this systematic review, we assessed the effects of stress ulcer prophylaxis (SUP) with proton pump inhibitors (PPIs) or histamine-2 receptor antagonists (H2RAs) versus placebo or no prophylaxis in acutely ill hospitalised patients.

METHODS

We conducted the review according to the PRISMA statement, the Cochrane Handbook and GRADE, using conventional meta-analysis and trial sequential analysis (TSA). The primary outcomes were all-cause mortality, clinically important GI bleeding and serious adverse events (SAEs). The primary analyses included overall low risk of bias trials.

RESULTS

We included 65 comparisons from 62 trials (n = 9713); 43 comparisons were from intensive care units. Only three trials (n = 3596) had overall low risk of bias. We did not find an effect on all-cause mortality (RR 1.03, 95% CI 0.94 to 1.14; TSA-adjusted CI 0.90 to 1.18; high certainty). The rate of clinically important GI bleeding was lower with SUP (RR 0.62, 95% CI 0.43 to 0.89; TSA-adjusted CI 0.14 to 2.81; moderate certainty). We did not find a difference in pneumonia rates (moderate certainty). Effects on SAEs, Clostridium difficile enteritis, myocardial ischaemia and health-related quality of life (HRQoL) were inconclusive due to sparse data. Analyses of all trials regardless of risk of bias were consistent with the primary analyses.

CONCLUSIONS

We did not observe a difference in all-cause mortality or pneumonia with SUP. The incidence of clinically important GI bleeding was reduced with SUP, whereas any effects on SAEs, myocardial ischaemia, Clostridium difficile enteritis and HRQoL were inconclusive.

STUDY REGISTRATION

PROSPERO registration number CRD42017055676; published study protocol: Marker, et al 2017 in Systematic Reviews.

Time to onset of gastrointestinal bleeding in the SUP-ICU trial: A pre-planned substudy

BACKGROUND

The aetiology and risk factors for clinically important gastrointestinal bleeding (CIB) in adult ICU patients may differ according to the onset of CIB, which could affect the balance between benefits and harms of stress ulcer prophylaxis (SUP).

METHODS

We assessed the time to CIB in the Stress Ulcer Prophylaxis in the Intensive Care Unit (SUP-ICU) trial. We assessed if associations between baseline characteristics including allocation to SUP and CIB changed during time in the ICU, specifically in the later (after day 2) compared to the earlier (first 2 days) period, using Cox models adjusted for SAPS II and allocation to SUP. Additionally, we described baseline characteristics and CIB episodes stratified by earlier/later/no CIB and 90-day mortality status.

RESULTS

Clinically important gastrointestinal bleeding occurred in 110/3291 (3.3%) patients after a median of 6 (interquartile range 2-13) days; 25.5% of the episodes occurred early. Higher SAPS II was consistently associated with increased risk of CIB (hazard ratio (HR) 1.03, 95% confidence interval (CI) 1.01-1.05 in the earlier period vs HR 1.02, 95% CI 1.01-1.03 in the later period; P = .37); university hospital admission was associated with decreased risk of earlier CIB (HR 0.30, 95% CI 0.14-0.63); this significantly increased in the later period (to HR 0.85, 95% CI 0.53-1.37; P = .02). Patients with later compared to earlier CIB received more transfusions and had more diagnostic/therapeutic procedures for CIB.

CONCLUSIONS

Clinically important gastrointestinal bleeding mostly occurred more than 2 days after randomization. University hospital admission was associated with significantly decreased risk of CIB in the earlier period only.

External validation of the Simplified Mortality Score for the Intensive Care Unit (SMS-ICU)

BACKGROUND

The Simplified Mortality Score for the Intensive Care Unit (SMS-ICU) is a clinical prediction model, which estimates the risk of 90-day mortality in acutely ill adult ICU patients using 7 readily available variables. We aimed to externally validate the SMS-ICU and compare its discrimination with existing prediction models used with 90-day mortality as the outcome.

METHODS

We externally validated the SMS-ICU using data from 3282 patients included in the Stress Ulcer Prophylaxis in the Intensive Care Unit trial, which randomised acutely ill adult ICU patients with risk factors for gastrointestinal bleeding to prophylactic pantoprazole or placebo in 33 ICUs in Europe. We assessed discrimination, calibration and overall performance of the SMS-ICU and compared discrimination with the commonly used and more complex SAPS II and SOFA scores.

RESULTS

Mortality at day 90 was 30.7%. The discrimination (area under the receiver operating characteristic curve) for the SMS-ICU was 0.67 (95% CI: 0.65-0.69), as compared with 0.68 (95% CI: 0.66-0.70, P = 0.35) for SAPS II and 0.63 (95% CI: 0.61-0.65, P < 0.001) for the SOFA score. Calibration (intercept and slope) was 0.001 and 0.786, respectively, and Nagelkerke's R² (overall performance) was 0.06. The proportions of missing data for the SMS-ICU, SAPS II and SOFA scores were 0.2%, 8.5% and 6.8%, respectively.

CONCLUSIONS

Discrimination for 90-day mortality of the SMS-ICU in this cohort was poor, but similar to SAPS II and better than that of the SOFA score with markedly less missing data.

Pantoprazole in ICU patients at risk for gastrointestinal bleeding-1-year mortality in the SUP-ICU trial

BACKGROUND

The long-term effects of stress ulcer prophylaxis with pantoprazole are unknown in ICU patients. We report 1-year mortality outcome in the Stress Ulcer Prophylaxis in the Intensive Care Unit (SUP-ICU) trial.

METHODS

In the SUP-ICU trial, acutely admitted adult ICU patients at risk of gastrointestinal bleeding were randomised to intravenous pantoprazole 40 mg vs placebo (saline) once daily during their ICU stay. We assessed mortality at 1 year and did sensitivity analyses according to the trial protocol and statistical analysis plan.

RESULTS

A total of 3261 of the 3291 patients with available data (99.1%) were followed up at 1 year after randomisation; 1635 were allocated to pantoprazole and 1626 to placebo. At 1 year after randomisation, 610 of 1635 patients (37.3%) had died in the pantoprazole group as compared with 601 of 1626 (37.0%) in the placebo group (relative risk, 1.01; 95% confidence interval 0.92-1.10). The results were consistent in the sensitivity analysis adjusted for baseline risk factors and in those of the per-protocol population. We did not observe heterogeneity in the effect of pantoprazole vs placebo on 1-year mortality in the predefined subgroups, that is, patients with and without shock, mechanical ventilation, liver disease, coagulopathy, high disease severity (SAPS II > 53) or in medical vs surgical ICU patients.

CONCLUSION

We did not observe a difference in 1-year mortality among acutely admitted adult ICU patients with risk factors for gastrointestinal bleeding allocated to stress ulcer prophylaxis with pantoprazole or placebo during the ICU stay. (The SUP-ICU trial was funded by Innovation Fund Denmark and others; ClinicalTrials.gov number, NCT02467621).

Heterogeneity of treatment effect of stress ulcer prophylaxis in ICU patients: A secondary analysis protocol

BACKGROUND

In the Stress Ulcer Prophylaxis in the Intensive Care Unit (SUP-ICU) trial, 3291 adult ICU patients at risk for gastrointestinal (GI) bleeding were randomly allocated to intravenous pantoprazole 40 mg or placebo once daily in the ICU. No difference was observed between the groups in the primary outcome 90-day mortality or the secondary outcomes, except for clinically important gastrointestinal bleeding. However, heterogeneity of treatment effect (HTE) not detected by conventional subgroup analyses could be present.

METHODS

This is a protocol and statistical analysis plan for a secondary, post hoc, exploratory analysis of the SUP-ICU trial. We will explore HTE in one set of subgroups based on severity of illness (using the Simplified Acute Physiology Score [SAPS] II) and another set of subgroups based on the total number of risk factors for GI bleeding in each patient using Bayesian hierarchical models. We will summarise posterior probability distributions using medians and 95% credible intervals and present probabilities for different levels of benefit and harm of the intervention in each subgroup. Finally, we will assess if the treatment effect interacts with SAPS II and the number of risk factors separately on the continuous scale using marginal effects plots.

CONCLUSIONS

The outlined post hoc analysis will explore whether HTE was present in the SUP-ICU trial and may help answer some of the remaining questions regarding the balance between benefits and harms of pantoprazole in ICU patients at risk of GI bleeding. CLINICALTRIALS.

GOV REGISTRATION

NCT02467621.

Outcomes of Prophylactic Pantoprazole in Adult Intensive Care Unit Patients Receiving Dialysis: Results of a Randomized Trial

BACKGROUND

Intensive care unit (ICU) patients with acute kidney injury requiring renal replacement therapy (RRT) are considered at high risk of gastrointestinal (GI) bleeding and stress ulcer prophylaxis (SUP) is often prescribed. We aimed to assess the incidence of GI bleeding and effects of SUP in these patients.

METHODS

We assessed GI bleeding in ICU patients receiving RRT at baseline (and at any time in the ICU) and effects of prophylactic pantoprazole versus placebo in the international SUP in the ICU (SUP-ICU) trial. All analyses were conducted according to a published protocol and statistical analysis plan.

RESULTS

Data of 3,291 acutely admitted adult ICU patients with one or more risk factors for GI bleeding randomized to pantoprazole or placebo intravenously once daily during ICU stay (until ICU discharge, death, or a maximum of 90 days) were analyzed. Some 20 out of 258 (7.8%, 95% CI 4.5-11.1%) and 52 out of 568 (9.2%, 95% CI 6.8-11.6%) of the patients receiving RRT at baseline and at any time in ICU, respectively, developed clinically important GI bleeding in the ICU. We did not observe statistically significant differences in the intervention effect (pantoprazole vs. placebo) in the proportion of patients with clinically important GI bleeding, clinically important events, infectious adverse events, use of interventions to stop GI bleeding, or 90-day mortality in patients with versus without RRT at baseline.

CONCLUSIONS

In adult ICU patients receiving RRT at baseline, we observed high incidences of clinically important GI bleeding, but did not observe effects of pantoprazole versus placebo in this subgroup.

Stress ulcer prophylaxis with proton pump inhibitors or histamin-2 receptor antagonists in adult intensive care patients: a systematic review with meta-analysis and trial sequential analysis

PURPOSE

Most intensive care unit (ICU) patients receive stress ulcer prophylaxis. We present updated evidence on the effects of prophylactic proton pump inhibitors (PPIs) or histamine 2 receptor antagonists (H2RAs) versus placebo/no prophylaxis on patient-important outcomes in adult ICU patients.

METHODS

We conducted a systematic review with meta-analysis and trial sequential analysis (TSA) of randomised clinical trials assessing the effects of PPI/H2RA versus placebo/no prophylaxis on mortality, gastrointestinal (GI) bleeding, serious adverse events (SAEs), health-related quality of life (HRQoL), myocardial ischemia, pneumonia, and Clostridium (Cl.) difficile enteritis in ICU patients.

RESULTS

We identified 42 trials randomising 6899 ICU patients; 3 had overall low risk of bias. We did not find an effect of stress ulcer prophylaxis on mortality [relative risk 1.03, 95% confidence interval (CI) 0.94-1.14; TSA-adjusted CI 0.94-1.14], but the occurrence of any GI bleeding was reduced as compared with placebo/no prophylaxis (0.60, 95% CI 0.47-0.77; TSA-adjusted CI 0.36-1.00). The conventional meta-analysis indicated that clinically important GI bleeding was reduced (RR 0.63, 95% CI 0.48-0.81), but the TSA-adjusted CI 0.35-1.13 indicated lack of firm evidence. The effects of stress ulcer prophylaxis on SAEs, HRQoL, pneumonia, myocardial ischemia and Cl. difficile enteritis are uncertain.

CONCLUSIONS

In this updated systematic review, we were able to refute a relative change of 20% of mortality. The occurrence of GI bleeding was reduced, but we lack firm evidence for a reduction in clinically important GI bleeding. The effects on SAEs, HRQoL, pneumonia, myocardial ischemia and Cl. difficile enteritis remain inconclusive.

Pantoprazole in Patients at Risk for Gastrointestinal Bleeding in the ICU

BACKGROUND

Prophylaxis for gastrointestinal stress ulceration is frequently given to patients in the intensive care unit (ICU), but its risks and benefits are unclear.

METHODS

In this European, multicenter, parallel-group, blinded trial, we randomly assigned adults who had been admitted to the ICU for an acute condition (i.e., an unplanned admission) and who were at risk for gastrointestinal bleeding to receive 40 mg of intravenous pantoprazole (a proton-pump inhibitor) or placebo daily during the ICU stay. The primary outcome was death by 90 days after randomization.

RESULTS

A total of 3298 patients were enrolled; 1645 were randomly assigned to the pantoprazole group and 1653 to the placebo group. Data on the primary outcome were available for 3282 patients (99.5%). At 90 days, 510 patients (31.1%) in the pantoprazole group and 499 (30.4%) in the placebo group had died (relative risk, 1.02; 95% confidence interval [CI], 0.91 to 1.13; P=0.76). During the ICU stay, at least one clinically important event (a composite of clinically important gastrointestinal bleeding, pneumonia, Clostridium difficile infection, or myocardial ischemia) had occurred in 21.9% of patients assigned to pantoprazole and 22.6% of those assigned to placebo (relative risk, 0.96; 95% CI, 0.83 to 1.11). In the pantoprazole group, 2.5% of patients had clinically important gastrointestinal bleeding, as compared with 4.2% in the placebo group. The number of patients with infections or serious adverse reactions and the percentage of days alive without life support within 90 days were similar in the two groups.

CONCLUSIONS

Among adult patients in the ICU who were at risk for gastrointestinal bleeding, mortality at 90 days and the number of clinically important events were similar in those assigned to pantoprazole and those assigned to placebo. (Funded by Innovation Fund Denmark and others; SUP-ICU ClinicalTrials.gov number, NCT02467621 .).

Stress ulcer prophylaxis in adult intensive care unit patients - a protocol for a systematic review

BACKGROUND

In the intensive care unit (ICU), stress ulcer prophylaxis with proton pump inhibitors or histamine-2-receptor antagonists is standard of care although gastrointestinal bleeding remains uncommon. It remains unknown whether its use is associated with benefits or harms and the quality of evidence supporting the use of stress ulcer prophylaxis has been questioned. Accordingly, the objective of this systematic review was to critically assess the evidence from randomized clinical trials on the benefits and harms of stress ulcer prophylaxis vs. placebo or no prophylaxis in adult ICU patients.

METHODS

We will systematically search for randomized clinical trials in major international databases. Two authors will independently screen and select trials for inclusion, extract data and assess the methodological quality using the Cochrane risk of bias tool. Any disagreement will be resolved by consensus. We will perform conventional meta-analyses using Review Manager, and STATA 15, and we will assess the risk of random errors using Trial Sequential Analysis. Also, we will assess and report the overall quality of evidence for all outcomes according to GRADE.

DISCUSSION

The evidence on the benefits and harms of stress ulcer prophylaxis in adult ICU patients is unclear and an updated systematic review is warranted as new trials have been published. To control risks of systematic and random errors, we will use Cochrane and GRADE methodology and Trial Sequential Analysis. Our ambition with this systematic review is to provide updated, reliable and precise data to better inform decision makers on the use of stress ulcer prophylaxis in adult ICU patients.

Timing of onset of gastrointestinal bleeding in the ICU: Protocol for a preplanned observational study

BACKGROUND

Critically ill patients are at risk of gastrointestinal bleeding, but clinically important gastrointestinal bleeding is rare. The majority of intensive care unit (ICU) patients receive stress ulcer prophylaxis (SUP), despite uncertainty concerning the balance between benefit and harm. For approximately half of ICU patients with gastrointestinal bleeding, onset is early, ie within the first two days of the ICU stay. The aetiology of gastrointestinal bleeding and consequently the balance between benefit and harm of SUP may differ between patients with early vs late gastrointestinal bleeding.

METHODS

This is a protocol and statistical analysis plan for a preplanned exploratory substudy of the Stress Ulcer Prophylaxis in the Intensive Care Unit (SUP-ICU) randomized clinical trial, comparing intravenous pantoprazole (40 mg once daily) with placebo in 3350 acutely ill adult ICU patients. We will describe baseline characteristics and assess the time to onset of the first clinically important episode of GI bleeding accounting for survival status and allocation to SUP or placebo. In addition, we will describe differences in therapeutic and diagnostic procedures used in patients with clinically important gastrointestinal bleeding according to early vs late bleeding and 90-day vital status.

CONCLUSIONS

The study outlined in this protocol will provide detailed information on patient characteristics and the timing of onset of gastrointestinal bleeding in the patients enrolled in the SUP-ICU trial. This may provide additional knowledge and incentives for future studies on which patients benefit from SUP.

Atraumatic versus conventional lumbar puncture needles: a systematic review and meta-analysis

BACKGROUND

Atraumatic needles have been proposed to lower complication rates after lumbar puncture. However, several surveys indicate that clinical adoption of these needles remains poor. We did a systematic review and meta-analysis to compare patient outcomes after lumbar puncture with atraumatic needles and conventional needles.

METHODS

In this systematic review and meta-analysis, we independently searched 13 databases with no language restrictions from inception to Aug 15, 2017, for randomised controlled trials comparing the use of atraumatic needles and conventional needles for any lumbar puncture indication. Randomised trials comparing atraumatic and conventional needles in which no dural puncture was done (epidural injections) or without a conventional needle control group were excluded. We screened studies and extracted data from published reports independently. The primary outcome of postdural-puncture headache incidence and additional safety and efficacy outcomes were assessed by random-effects and fixed-effects meta-analysis. This study is registered with the International Prospective Register of Systematic Reviews, number CRD42016047546.

FINDINGS

We identified 20 241 reports; after exclusions, 110 trials done between 1989 and 2017 from 29 countries, including a total of 31 412 participants, were eligible for analysis. The incidence of postdural-puncture headache was significantly reduced from 11·0% (95% CI 9·1-13·3) in the conventional needle group to 4·2% (3·3-5·2) in the atraumatic group (relative risk 0·40, 95% CI 0·34-0·47, p<0·0001; I²=45·4%). Atraumatic needles were also associated with significant reductions in the need for intravenous fluid or controlled analgesia (0·44, 95% CI 0·29-0·64; p<0·0001), need for epidural blood patch (0·50, 0·33-0·75; p=0·001), any headache (0·50, 0·43-0·57; p<0·0001), mild headache (0·52, 0·38-0·70; p<0·0001), severe headache (0·41, 0·28-0·59; p<0·0001), nerve root irritation (0·71, 0·54-0·92; p=0·011), and hearing disturbance (0·25, 0·11-0·60; p=0·002). Success of lumbar puncture on first attempt, failure rate, mean number of attempts, and the incidence of traumatic tap and backache did not differ significantly between the two needle groups. Prespecified subgroup analyses of postdural-puncture headache revealed no interactions between needle type and patient age, sex, use of prophylactic intravenous fluid, needle gauge, patient position, indication for lumbar puncture, bed rest after puncture, or clinician specialty. These results were rated high-quality evidence as examined using the grading of recommendations assessment, development, and evaluation.

INTERPRETATION

Among patients who had lumbar puncture, atraumatic needles were associated with a decrease in the incidence of postdural-puncture headache and in the need for patients to return to hospital for additional therapy, and had similar efficacy to conventional needles. These findings offer clinicians and stakeholders a comprehensive assessment and high-quality evidence for the safety and efficacy of atraumatic needles as a superior option for patients who require lumbar puncture.

FUNDING

None.

Development and internal validation of the Simplified Mortality Score for the Intensive Care Unit (SMS-ICU)

BACKGROUND

Intensive care unit (ICU) mortality prediction scores deteriorate over time, and their complexity decreases clinical applicability and commonly causes problems with missing data. We aimed to develop and internally validate a new and simple score that predicts 90-day mortality in adults upon acute admission to the ICU: the Simplified Mortality Score for the Intensive Care Unit (SMS-ICU).

METHODS

We used data from an international cohort of 2139 patients acutely admitted to the ICU and 1947 ICU patients with severe sepsis/septic shock from 2009 to 2016. We performed multiple imputations for missing data and used binary logistic regression analysis with variable selection by backward elimination, followed by conversion to a simple point-based score. We assessed the apparent performance and validated the score internally using bootstrapping to present optimism-corrected performance estimates.

RESULTS

The SMS-ICU comprises seven variables available in 99.5% of the patients: two numeric variables: age and lowest systolic blood pressure, and five dichotomous variables: haematologic malignancy/metastatic cancer, acute surgical admission and use of vasopressors/inotropes, respiratory support and renal replacement therapy. Discrimination (area under the receiver operating characteristic curve) was 0.72 (95% CI: 0.71-0.74), overall performance (Nagelkerke's R² ) was 0.19 and calibration (intercept and slope) was 0.00 and 0.99, respectively. Optimism-corrected performance was similar to apparent performance.

CONCLUSIONS

The SMS-ICU predicted 90-day mortality with reasonable and stable performance. If performance remains adequate after external validation, the SMS-ICU could prove a valuable tool for ICU clinicians and researchers because of its simplicity and expected very low number of missing values.

Effects of stress ulcer prophylaxis in adult ICU patients receiving renal replacement therapy (Sup-Icu RENal, SIREN): Study protocol for a pre-planned observational study

Background

Proton pump inhibitors are often used in critically ill patients to prevent gastrointestinal bleeding despite limited evidence for benefit. Patients with acute kidney injury requiring renal replacement therapy (RRT) are at high risk of gastrointestinal bleeding as (pre-)uremia induces coagulopathy through effects on platelets and coagulation cascades. No high-quality randomized clinical trials have previously assessed the benefits and harms of prophylactic proton pump inhibitor use in this high-risk population of adult critically ill patients.

Methods/design

Among the 3350 patients included in the Stress Ulcer Prophylaxis in the Intensive Care Unit (SUP-ICU) trial—an investigator-initiated international randomized clinical trial on prophylactic proton pump inhibitor versus placebo in acutely admitted adult ICU patients at risk of gastrointestinal bleeding—we will compare the benefits and harms of prophylactic use of proton pump inhibitor in patients in need of RRT versus those not requiring this treatment. We will determine the proportion of patients with clinically important bleeding, the proportion of patients with adverse events including pneumonia, Clostridium difficile enteritis, or acute myocardial ischemia in the ICU, as well as transfusion requirements. Moreover, 90 day and 365 day mortality post-randomization will be investigated. As a secondary analysis, we will examine the association between acute kidney injury and RRT during ICU stay and gastrointestinal bleeding.

Discussion

With the outlined predefined analysis, we will characterize the balance between the benefits and harms of stress ulcer prophylaxis in acutely admitted adult ICU patients in need of RRT, including the potential interaction of allocation to proton pump inhibitor versus placebo.

Trial registration

ClinicalTrials.gov, NCT02718261. Registered on 14 March 2016.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-017-2408-3) contains supplementary material, which is available to authorized users.

Correction to: Efficacy and safety of stress ulcer prophylaxis in critically ill patients: a network meta-analysis of randomized trials

Owing to an oversight by the authors, all the figures in the last column of Table 2 (upper section: Number needed to treat; lower section: Number needed to harm) in this article were given without the final digit 0 and are thus 10 times too small.

Efficacy and safety of stress ulcer prophylaxis in critically ill patients: a network meta-analysis of randomized trials

PURPOSE

Stress ulcer prophylaxis (SUP) is commonly prescribed in the intensive care unit. However, data from systematic reviews and conventional meta-analyses are limited by imprecision and restricted to direct comparisons. We conducted a network meta-analysis of randomized clinical trials (RCTs) to examine the safety and efficacy of drugs available for SUP in critically ill patients.

METHODS

We searched MEDLINE, EMBASE, and the Cochrane Library Central Register of Controlled Trials through April 2017 for randomized controlled trials that examined the efficacy and safety of proton pump inhibitors (PPIs), histamine-2 receptor antagonists (H2RAs), and sucralfate for SUP in critically ill patients. No date or language restrictions were applied. Data on study characteristics, methods, outcomes, and risk of bias were abstracted by two reviewers.

RESULTS

Of 96 potentially eligible studies, we included 57 trials enrolling 7293 patients. The results showed that PPIs are probably more effective for preventing clinically important gastrointestinal bleeding (CIB) than H2RAs [odds ratio (OR) 0.38; 95% confidence interval (95% CI) 0.20, 0.73], sucralfate (OR 0.30; 95% CI 0.13, 0.69), and placebo (OR 0.24; 95% CI 0.10, 0.60) (all moderate quality evidence). There were no convincing differences among H2RA, sucralfate, and placebo. PPIs probably increase the risk of developing pneumonia compared with H2RAs (OR 1.27; 95% CI 0.96, 1.68), sucralfate (OR 1.65; 95% CI 1.20, 2.27), and placebo (OR 1.52; 95% CI 0.95, 2.42) (all moderate quality). Mortality is probably similar across interventions (moderate quality). Estimates of baseline risks of bleeding varied significantly across studies, and only one study reported on Clostridium difficile infection. Definitions of pneumonia varied considerably. Most studies on sucralfate predate pneumonia prevention strategies.

CONCLUSIONS

Our results provide moderate quality evidence that PPIs are the most effective agents in preventing CIB, but they may increase the risk of pneumonia. The balance of benefits and harms leaves the routine use of SUP open to question.

Stress ulcer prophylaxis in the intensive care unit trial: detailed statistical analysis plan

BACKGROUND

In this statistical analysis plan, we aim to provide details of the pre-defined statistical analyses of the Stress Ulcer Prophylaxis in the Intensive Care Unit (SUP-ICU) trial. The aim of the SUP-ICU trial is to assess benefits and harms of stress ulcer prophylaxis with a proton pump inhibitor in adult patients in the intensive care unit (ICU).

METHODS

The SUP-ICU trial is an investigator-initiated, international, multicentre, randomised, blinded, parallel-group trial of intravenously pantoprazole 40 mg once daily vs. placebo in 3350 acutely ill adult ICU patients at risk of gastrointestinal bleeding. The primary outcome measure is 90-day mortality. Secondary outcomes include the proportion of patients with clinically important gastrointestinal bleeding, pneumonia, Clostridium difficile infection or myocardial ischaemia, days alive without life support, serious adverse reactions, 1-year mortality, and a health economic analysis. Two formal interim analyses will be performed. The statistical analyses will be conducted according to the outlined pre-defined statistical analysis plan. The primary analysis will be a logistic regression analysis adjusted for stratification variables comparing the two intervention groups in the intention-to-treat population. In a secondary analysis, we will additionally adjust the primary outcome for potential random differences in baseline characteristics. The conclusion will be based on the intention-to-treat population.

CONCLUSION

Stress ulcer prophylaxis is standard of care in ICUs worldwide, but has never been tested in large high-quality randomised placebo-controlled trials. The SUP-ICU trial will provide important high-quality data on the balance between the benefits and harms of stress ulcer prophylaxis in adult critically ill patients.

Stress ulcer prophylaxis versus placebo or no prophylaxis in adult hospitalised acutely ill patients-protocol for a systematic review with meta-analysis and trial sequential analysis

BACKGROUND

Stress ulcer prophylaxis is considered standard of care in many critically ill patients in the intensive care unit (ICU). However, the quality of evidence supporting this has recently been questioned, and clinical equipoise exists. Whether there is overall benefit or harm of stress ulcer prophylaxis in adult hospitalised acutely ill patients is unknown. Accordingly, we aim to assess patient-important benefits and harms of stress ulcer prophylaxis versus placebo or no treatment in adult hospitalised acutely ill patients with high risk of gastrointestinal bleeding irrespective of hospital setting.

METHODS/DESIGN

We will conduct a systematic review of randomised clinical trials with meta-analysis and trial sequential analysis and assess use of proton pump inhibitors (PPIs) or histamine-2-receptor antagonists (H2RAs) in any dose, formulation and duration. We will accept placebo or no prophylaxis as control interventions. The participants will be adult hospitalised acutely ill patients with high risk of gastrointestinal bleeding. We will systematically search the Cochrane Library, MEDLINE, EMBASE, Science Citation Index, BIOSIS and Epistemonikos for relevant literature. We will follow the recommendations by the Cochrane Collaboration and the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) statement. The risk of systematic errors (bias) and random errors will be assessed, and the overall quality of evidence will be evaluated using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach.

DISCUSSION

There is a need for a high-quality systematic review to summarise the benefits and harms of stress ulcer prophylaxis in hospitalised patients to inform practice and future research. Although stress ulcer prophylaxis is used worldwide, no firm evidence for benefit or harm as compared to placebo or no treatments has been established. Critical illness is a continuum not limited to the ICU setting, which is why it is important to assess the benefits and harms of stress ulcer prophylaxis in a wider perspective than exclusively in ICU patients.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42017055676.

Use of life support in acutely admitted ICU patients. An international cohort study

BACKGROUND

Use of life support in intensive care unit (ICU) patients has been associated with increased risk of poor outcome. The prognostic importance of the duration of support is less studied. We assessed the use of life support and the association between its duration and 90-day mortality in a contemporary cohort of acutely admitted adult ICU patients.

METHODS

We performed a post-hoc analysis of the SUP-ICU 7-day inception cohort study (n = 1034), which was conducted in 97 ICUs in 11 countries. We included patients with an ICU stay of 3 days or more. We assessed the use of life support during the first 3 days in ICU and the crude and adjusted association between its duration and 90-day mortality using logistic regression analyses.

RESULTS

We included 690 patients; their 90-day mortality was 23%. During the first 3 days in ICU mechanical ventilation was used in 65%, vasopressors/inotropes in 57% and renal replacement therapy in 13%. Renal replacement therapy for 3 days or more was associated with a higher 90-day mortality as compared with 1 day of renal replacement therapy [odds ratio 6.5 (95% confidence interval 1.3 to 32.8)]. For mechanical ventilation and vasopressors/inotropes the odds ratios were 2.2 [0.9 to 5.3] and 1.2 [0.5 to 2.6], respectively.

CONCLUSIONS

Among acutely admitted adult ICU patients, a higher number of days of renal replacement therapy in the initial ICU stay were associated with increased risk of death within 90 days. We did not observe such an association for mechanical ventilation or vasopressor/inotropic therapy.

Simplified Mortality Score for the Intensive Care Unit (SMS-ICU): protocol for the development and validation of a bedside clinical prediction rule

INTRODUCTION

Mortality prediction scores are widely used in intensive care units (ICUs) and in research, but their predictive value deteriorates as scores age. Existing mortality prediction scores are imprecise and complex, which increases the risk of missing data and decreases the applicability bedside in daily clinical practice. We propose the development and validation of a new, simple and updated clinical prediction rule: the Simplified Mortality Score for use in the Intensive Care Unit (SMS-ICU).

METHODS AND ANALYSIS

During the first phase of the study, we will develop and internally validate a clinical prediction rule that predicts 90-day mortality on ICU admission. The development sample will comprise 4247 adult critically ill patients acutely admitted to the ICU, enrolled in 5 contemporary high-quality ICU studies/trials. The score will be developed using binary logistic regression analysis with backward stepwise elimination of candidate variables, and subsequently be converted into a point-based clinical prediction rule. The general performance, discrimination and calibration of the score will be evaluated, and the score will be internally validated using bootstrapping. During the second phase of the study, the score will be externally validated in a fully independent sample consisting of 3350 patients included in the ongoing Stress Ulcer Prophylaxis in the Intensive Care Unit trial. We will compare the performance of the SMS-ICU to that of existing scores.

ETHICS AND DISSEMINATION

We will use data from patients enrolled in studies/trials already approved by the relevant ethical committees and this study requires no further permissions. The results will be reported in accordance with the Transparent Reporting of multivariate prediction models for Individual Prognosis Or Diagnosis (TRIPOD) statement, and submitted to a peer-reviewed journal.

Stress ulcer prophylaxis with a proton pump inhibitor versus placebo in critically ill patients (SUP-ICU trial): study protocol for a randomised controlled trial

Background

Critically ill patients in the intensive care unit (ICU) are at risk of clinically important gastrointestinal bleeding, and acid suppressants are frequently used prophylactically. However, stress ulcer prophylaxis may increase the risk of serious adverse events and, additionally, the quantity and quality of evidence supporting the use of stress ulcer prophylaxis is low. The aim of the SUP-ICU trial is to assess the benefits and harms of stress ulcer prophylaxis with a proton pump inhibitor in adult patients in the ICU. We hypothesise that stress ulcer prophylaxis reduces the rate of gastrointestinal bleeding, but increases rates of nosocomial infections and myocardial ischaemia. The overall effect on mortality is unpredictable.

Methods/design

The SUP-ICU trial is an investigator-initiated, pragmatic, international, multicentre, randomised, blinded, parallel-group trial of stress ulcer prophylaxis with a proton pump inhibitor versus placebo (saline) in 3350 acutely ill ICU patients at risk of gastrointestinal bleeding. The primary outcome measure is 90-day mortality. Secondary outcomes include the proportion of patients with clinically important gastrointestinal bleeding, pneumonia, Clostridium difficile infection or myocardial ischaemia, days alive without life support in the 90-day period, serious adverse reactions, 1-year mortality, and health economic analyses.

The sample size will enable us to detect a 20 % relative risk difference (5 % absolute risk difference) in 90-day mortality assuming a 25 % event rate with a risk of type I error of 5 % and power of 90 %. The trial will be externally monitored according to Good Clinical Practice standards. Interim analyses will be performed after 1650 and 2500 patients.

Conclusion

The SUP-ICU trial will provide high-quality data on the benefits and harms of stress ulcer prophylaxis with a proton pump inhibitor in critically ill adult patients admitted in the ICU.

Trial registration

ClinicalTrials.gov Identifier: NCT02467621.

Ultrasound-guided nerve blocks--is documentation and education feasible using only text and pictures?

PURPOSE

With the advancement of ultrasound-guidance for peripheral nerve blocks, still pictures from representative ultrasonograms are increasingly used for clinical procedure documentation of the procedure and for educational purposes in textbook materials. However, little is actually known about the clinical and educational usefulness of these still pictures, in particular how well nerve structures can be identified compared to real-time ultrasound examination. We aimed to quantify gross visibility or ultrastructure using still picture sonograms compared to real time ultrasound for trainees and experts, for large or small nerves, and discuss the clinical or educational relevance of these findings.

MATERIALS AND METHODS

We undertook a clinical study to quantify the maximal gross visibility or ultrastructure of seven peripheral nerves identified by either real time ultrasound (clinical cohort, n = 635) or by still picture ultrasonograms (clinical cohort, n = 112). In addition, we undertook a study on test subjects (n = 4) to quantify interobserver variations and potential bias among expert and trainee observers.

RESULTS

When comparing real time ultrasound and interpretation of still picture sonograms, gross identification of large nerves was reduced by 15% and 40% by expert and trainee observers, respectively, while gross identification of small nerves was reduced by 29% and 66%. Identification of within-nerve ultrastructure was even less. For all nerve sizes, trainees were unable to identify any anatomical structure in 24 to 34%, while experts were unable to identify anything in 9 to 10%.

CONCLUSION

Exhaustive ultrasonography experience and real time ultrasound measurements seem to be keystones in obtaining optimal nerve identification. In contrast the use of still pictures appears to be insufficient for documentation as well as educational purposes. Alternatives such as video clips or enhanced picture technology are encouraged instead of still pictures extracted from basic ultrasonograms.

Stress ulcer prophylaxis versus placebo or no prophylaxis in critically ill patients. A systematic review of randomised clinical trials with meta-analysis and trial sequential analysis

PURPOSE

To assess the effects of stress ulcer prophylaxis (SUP) versus placebo or no prophylaxis on all-cause mortality, gastrointestinal (GI) bleeding and hospital-acquired pneumonia in adult critically ill patients in the intensive care unit (ICU).

METHODS

We performed a systematic review using meta-analysis and trial sequential analysis (TSA). Eligible trials were randomised clinical trials comparing proton pump inhibitors or histamine 2 receptor antagonists with either placebo or no prophylaxis. Two reviewers independently assessed studies for inclusion and extracted data. The Cochrane Collaboration methodology was used. Risk ratios/relative risks (RR) with 95% confidence intervals (CI) were estimated. The predefined outcome measures were all-cause mortality, GI bleeding, and hospital-acquired pneumonia.

RESULTS

Twenty trials (n = 1,971) were included; all were judged as having a high risk of bias. There was no statistically significant difference in mortality (fixed effect: RR 1.00, 95% CI 0.84-1.20; P = 0.87; I(2) = 0%) or hospital-acquired pneumonia (random effects: RR 1.23, 95% CI 0.86-1.78; P = 0.28; I(2) = 19%) between SUP patients and the no prophylaxis/placebo patients. These findings were confirmed in the TSA. With respect to GI bleeding, a statistically significant difference was found in the conventional meta-analysis (random effects: RR 0.44, 95% CI 0.28-0.68; P = 0.01; I(2) = 48%); however, TSA (TSA adjusted 95% CI 0.18-1.11) and subgroup analyses could not confirm this finding.

CONCLUSIONS

This systematic review using meta-analysis and TSA demonstrated that both the quality and the quantity of evidence supporting the use of SUP in adult ICU patients is low. Consequently, large randomised clinical trials are warranted.

Exercise, hormones, and body temperature. regulation and action of GH during exercise

That physical exercise stimulates pituitary GH secretion has been known for forty years, but the underlying mechanisms as well as the physiological significance remain elusive. We have previously shown that the concomitant increase in core temperature is essential for the exercise-induced GH release, inasmuch as exercise performed at 4 C results in a suppression of GH secretion, whereas passive heating constitutes a potent stimulus for GH release. Moreover, studies in normal subjects show that GH stimulates sweat production and evaporative heat loss during heat exposure with and without exercise, whereas GH-deficiency is associated with reduced sweat secretion and increased heat storage during similar conditions. The neurotransmitters involved in GH secretion during exercise remain uncertain; we therefore investigated the putative role of ghrelin, which is a gut-derived endogenous ligand for the GHS receptor. We measured circulating ghrelin levels before during and after submaximal aerobic exercise in healthy subjects and GH-deficient patients. The circulating ghrelin levels were unchanged during and after exercise in all subjects. Growth hormone stimulates lipolysis and lipid oxidation during basal and fasting conditions and we recently investigated whether GH also regulates substrate metabolism during exercise. The design involved GH-deficient patients studied during exercise with and without GH administration as compared to untreated healthy subjects. Growth hormone predominantly stimulated the turnover of free fatty acids in the recovery phase after exercise.

CONCLUSIONS

1) the increase in GH release during exercise is associated with the concomitant increase in body temperature, 2) GH stimulates sweat secretion and heat evaporation during exercise, which seems to be of distinct physiological significance, 3) ghrelin is not involved in exercise-induced GH release, 4) the impact of GH on substrate metabolism during exercise includes increased FFA turnover.

A study of stiffness protocol as exemplified by testing of a burst fracture model in sagittal plane

STUDY DESIGN

An in vitro biomechanical study of lumbar spine segments.

OBJECTIVE

To study the characteristics of the stiffness test protocol.

SUMMARY OF BACKGROUND DATA

In an in vitro study using a flexibility protocol, forces are applied and motions are measured; no center of rotation needs to be specified. In a study using a stiffness protocol, the forces are measured and the motions are applied. This does require the center of rotation to be specified. Many biomechanical studies of the spine are available, but there is lack of clarity concerning which of these two test protocols is appropriate to achieve a certain study goal.

METHODS

Five-vertebrae lumbar spine specimens with burst fractures in the middle vertebrae (L1) were used. Specially designed apparatus applied flexion and extension rotations around five centers of rotations located on anteroposterior line through the middle of L1. Maximum moment of 4 Nm was applied.

RESULTS

The authors found load-displacement curves, ranges of motion, and neutral zones obtained at the five centers of rotations to be markedly different. The center of rotation located at the posterior longitudinal ligament produced large range of motion and neutral zones in comparison to the centers of rotation located at the anterior longitudinal ligament and the spinous process tip (P<0.01).

CONCLUSIONS

The stiffness protocol requires that a center of rotation be specified. Shown here is the significant variability in the load-displacement curves, depending on the choice of the location of the center of rotation. Certain center of rotation locations may block the natural motions of the spine and may result in tissue damage.

Articular facets of the human spine. Quantitative three-dimensional anatomy

This study provides the quantitative three-dimensional surface anatomy of the articular facets for the entire human vertebral column based on a study of 276 vertebrae. Means and standard errors of the means for linear, angular, and area dimensions of the superior and inferior articular facets were measured for all vertebrae from C2 to L5. Facet orientations were described as angles with respect to the sagittal and transverse planes and also as card angles. The plane angles are similar to the angles seen on traditional radiographic views--radiographs and computed tomographic scans. The card angles, a new concept, are better at helping visualize the three-dimensional orientations of the facets. Excluding the superior C2 facet, the following minimum and maximum dimensions were found for the facets from C3 to L5: width = 9.6-16.3 mm; height = 10.2-18.4; surface area = 72.3-211.9 mm2; interfacet width = 20.8-40.6; interfacet height = 12.2-33.0 mm; transverse plane angle = 41.0-86.0; sagittal plane angle = 67.4-154.8; X-card angle = 41.0-86.0; and Y-card angle = 5.8-66.1. The quantitative anatomy of the facets may improve the understanding of the spinal anatomy, help improve the clinical diagnosis and treatment, and provide the necessary data for constructing more realistic mathematical models of the spine.

External fixator pin design

The integrity of the bone-pin interface is the critical link in the stability of external fixation systems. External fixation pins placed in cancellous metaphyseal bone frequently loosen over time, resulting in fixation failure and an increased risk of infection. To design an external fixation pin with optimal bone-metal interface strength in cancellous bone, a systematic study of various thread design features was performed. Combinations of pitch, tooth profile, and minor diameter in 5 mm self-tapping half pins were evaluated in coaxial pullout testing using a fresh bovine cancellous bone. A significant increase in pullout strength was found with a decrease in minor diameter. No statistical differences were found in pullout strength attributable to thread profile and pitch. There were no significant interactions between minor diameter and tooth profile or minor diameter and pitch. The data obtained suggest significantly greater holding power in cancellous bone can be achieved by using an external fixation pin with a smaller minor diameter or a larger interference. Additional pullout testing of five commercially available external fixator pins was performed. Of these, the two pins with the largest interference demonstrated greater pullout strength. Therefore, within a range of acceptable major diameters and adequate minor diameters for the torsional strength requirements, an optimal interference for cancellous pin application may exist and it may well be larger than that present in currently available external fixation pins.

Human lumbar vertebrae. Quantitative three-dimensional anatomy

This study details the quantitative three-dimensional surface anatomy of human lumbar vertebrae based on a study of 60 vertebrae. The two lower vertebrae (L4 and L5) appeared to be transitional toward the sacral region, whereas the upper two vertebrae (L1 and L2) were transitional toward the thoracic region. Means and standard errors of the means for linear, angular, and area dimensions of vertebral bodies, spinal canal, pedicle, pars interarticularis, spinous and transverse processes were obtained for all lumbar vertebrae. This information provides a better understanding of the spine, and allows for a more precise clinical diagnosis and surgical management of spinal problems. The information is also necessary for constructing accurate mathematical models of the human spine.

Thoracic human vertebrae. Quantitative three-dimensional anatomy

This study details the quantitative three-dimensional surface anatomy of thoracic vertebrae based on a study of 144 vertebrae. The thoracic spine was found to have three distinct regions: upper, middle, and lower segments. The two end segments appear to be transitional zones toward cervical and lumbar regions. The middle zone (T3 to T9) is of utmost importance due to the presence of the combination of narrow spinal canal and critical vascular supply. Means and standard errors of the means for linear, angular, and area dimensions of vertebral bodies, spinal canal, pedicle, pars articularis, spinous and transverse processes, and rib articulations are provided for all thoracic vertebrae. This information is necessary for constructing accurate mathematical models of the human spine. It will also provide a better understanding of the spine, and allow for a more precise clinical and surgical management of spinal problems.

Lumbar paraspinal compartment syndrome. A case report with physiologic and anatomic studies

A 24-year-old man presented with severe low-back pain and paraspinal muscle spasm after exertion. Elevation in temperature, white blood cell count, serum muscle enzymes, and urine myoglobin, as well as computer tomographic evidence of paraspinal muscle edema and necrosis, were present. No etiology could be documented, and the possibility of an acute exertional compartment syndrome was entertained. Subsequently, cadaveric dis-sections indicated that the erector spinae muscles are contained within a well-developed fascial sheath. Continuous slit catheter pressure measurements within this compartment in eight healthy male subjects were subsequently carried out. These indicated a physiologic behavior similar to other known compartments for which compartment syndromes have been described. Variation in intracompartmental pressure occurred as a function of body posture, erector spinae isometric contraction, and active intra-abdominal pressurization. We suggest this patient had a paraspinal compartment syndrome and have described pressure characteristics of this compartment in normal men.