Why do multicenter randomized controlled trials not confirm the positive findings of single center randomized controlled trials in acute care?

The effectiveness of video training in improving intensive care nurses' knowledge about brain death identification

BACKGROUND

Because patients diagnosed with brain death in intensive care units constitute a potential cadaveric donor group for organ transplantation, intensive care units are potential donor sources. Nurses who closely monitor the patient collaborate with medical personnel in the recognition and early diagnosis of brain death. Nurses also have an important role in supporting the patient's family. Therefore, it is very important for nurses to know the diagnostic criteria for brain death.

AIM

The aim of this study was to compare the effectiveness of theoretical education and video-assisted education in equipping intensive care nurses to recognize brain death.

STUDY DESIGN

A randomized, experimental study was conducted between February and May 2020 with a total of 50 intensive care nurses, split into 25 in the video-assisted training group and 25 in the theoretical training group. In study, intensive care nurses were given a theoretical training and video-assisted training on brain death criteria. One group was trained theoretically and the other group used a video showing criteria for brainstem reflexes (pupil assessment, spontaneous breathing, corneal reflex, retching and coughing assessments) and deep tendon reflexes in a simulated patient, supported by animation. The data were collected before, immediately after and 3 months after the training using the Brain Death Criteria Knowledge Test, the Brain Death Case Test, and the Training Effectiveness Evaluation Form. The independent samples t-test, Mann-Whitney U test, Friedman test, Wilcoxon test, and Chi-square test were used for statistical analysis of data.

RESULTS

It was found that the knowledge scores of both groups immediately after training and 3 months after training were higher than before the training (p < .001). However, the post-training knowledge scores of the video-assisted training group were significantly higher than those of the theoretical training group (p = .011).

CONCLUSIONS

To enable intensive care nurses to identify brain death, video-assisted training with a simulated patient is recommended, as is repeating the training at regular intervals.

RELEVANCE TO CLINICAL PRACTICE

The simulated patient video-assisted training method can be used for in-service training to provide intensive care nurses with the ability to identify brain death. The training may be repeated at regular intervals (e.g., every 3 months) to increase nurse recall.

Extracorporeal Membrane Oxygenation Without Invasive Ventilation for Respiratory Failure in Adults: A Systematic Review

OBJECTIVES

Extracorporeal membrane oxygenation (ECMO) is an advanced treatment for acute severe respiratory failure. Patients on ECMO are frequently maintained sedated and immobilized until weaning from ECMO, first, and then from mechanical ventilation. Avoidance of sedation and invasive ventilation during ECMO may have potential advantages. We performed a systematic literature review to assess efficacy and safety of awake ECMO without invasive ventilation in patients with respiratory failure.

DATA SOURCES

PubMed, Web of Science, and Scopus were searched for studies reporting outcome of awake ECMO for adult patients with respiratory failure.

STUDY SELECTION

We included all studies reporting outcome of awake ECMO in patients with respiratory failure. Studies on ECMO for cardiovascular failure, cardiac arrest, or perioperative support and studies on pediatric patients were excluded. Two investigators independently screened and selected studies for inclusion.

DATA EXTRACTION

Two investigators abstracted data on study characteristics, rate of awake ECMO failure, and mortality. Primary outcome was rate of awake ECMO failure (need for intubation). Pooled estimates with corresponding 95% CIs were calculated. Subgroup analyses by setting were performed.

DATA SYNTHESIS

A total of 57 studies (28 case reports) included data from 467 awake ECMO patients. The subgroup of patients with acute respiratory distress syndrome showed a pooled estimate for awake ECMO failure of 39.3% (95% CI, 24.0-54.7%), while in patients bridged to lung transplantation, pooled estimate was 23.4% (95% CI, 13.3-33.5%). Longest follow-up mortality was 121 of 439 (pooled estimate, 28%; 95% CI, 22.3-33.6%). Mortality in patients who failed awake ECMO strategy was 43 of 74 (pooled estimate, 57.2%; 95% CI, 40.2-74.3%). Two cases of cannula self-removal were reported.

CONCLUSIONS

Awake ECMO is feasible in selected patients, although the effect on outcome remains to be demonstrated. Mortality is almost 60% in patients who failed awake ECMO strategy.

Positive single-center randomized trials and subsequent multicenter randomized trials in critically ill patients: a systematic review

BACKGROUND

It is unclear how often survival benefits observed in single-center randomized controlled trials (sRCTs) involving critically ill patients are confirmed by subsequent multicenter randomized controlled trials (mRCTs). We aimed to perform a systemic literature review of sRCTs with a statistically significant mortality reduction and to evaluate whether subsequent mRCTs confirmed such reduction.

METHODS

We searched PubMed for sRCTs published in the New England Journal of Medicine, JAMA, or Lancet, from inception until December 31, 2016. We selected studies reporting a statistically significant mortality decrease using any intervention (drug, technique, or strategy) in adult critically ill patients. We then searched for subsequent mRCTs addressing the same research question tested by the sRCT. We compared the concordance of results between sRCTs and mRCTs when any mRCT was available. We registered this systematic review in the PROSPERO International Prospective Register of Systematic Reviews (CRD42023455362).

RESULTS

We identified 19 sRCTs reporting a significant mortality reduction in adult critically ill patients. For 16 sRCTs, we identified at least one subsequent mRCT (24 trials in total), while the interventions from three sRCTs have not yet been addressed in a subsequent mRCT. Only one out of 16 sRCTs (6%) was followed by a mRCT replicating a significant mortality reduction; 14 (88%) were followed by mRCTs with no mortality difference. The positive finding of one sRCT (6%) on intensive glycemic control was contradicted by a subsequent mRCT showing a significant mortality increase. Of the 14 sRCTs referenced at least once in international guidelines, six (43%) have since been either removed or suggested against in the most recent versions of relevant guidelines.

CONCLUSION

Mortality reduction shown by sRCTs is typically not replicated by mRCTs. The findings of sRCTs should be considered hypothesis-generating and should not contribute to guidelines.

Disparities between randomized clinical trial participants and sepsis patients in real-world

BACKGROUND

The external validity or "generalizability" of randomized controlled trials (RCTs) often needs be considered when making treatment decisions. We evaluate whether participants in large multicenter RCTs investigating sepsis were similar in age, disease severity, comorbidities, and mortality to the general population of sepsis patients.

METHODS

Using MEDLINE, PubMed, and the Cochrane Central Register of Controlled Trials, RCTs that enrolled 100 or more adult sepsis patients from two or more sites published from 01 January 2000 to 04 August 2019 were identified. The weighted mean age of trial participants was calculated as the main variable, and it was compared with the mean ages of the overall populations derived from the MIMIC database and the EICU database. Two researchers independently screened all abstracts and performed data extraction, then aggregated the data using a random effects model. Multiple linear regression was used to determine whether any factors were significantly associated with age disparities.

RESULTS

The mean age of the 60,577 participants in the 94 trials included in the analysis was significantly lower than those of the patients in the MIMIC and EICU databases (weighted mean age 62.28 years vs. 64.47 years for MIMIC and 65.20 years for EICU; both p < 0.001). Trial participants were less likely to have known comorbidities such as diabetes (13.96% vs. 30.64% for MIMIC and 35.75% for EICU; both p < 0.001). The weighted mortality rate in trial participants was higher than that in patients in the MIMIC and EICU databases (29.33% vs. 20.72% for MIMIC and 17.53% for EICU; both p < 0.001). Differences in age, severity score, and comorbidities remained statistically significant in sensitivity analyses. Multivariable regression suggested that commercially supported trials were more likely to include patients with higher severity scores (p = 0.002), but after adjustment for study region and sepsis diagnosis inclusion in such trials was not significantly associated with age.

CONCLUSIONS

On average, trial participants were younger than the general sepsis patient population. Commercial support influenced patient selection. Efforts to understand and address the above-described patient disparities are necessary to improve the generalizability of RCT results.

TRIAL REGISTRATION

PROSPERO CRD42019145692.

Refractory out-of-hospital cardiac arrest and extracorporeal cardiopulmonary resuscitation: A meta-analysis of randomized trials

BACKGROUND

In adults with refractory out-of-hospital cardiac arrest, when conventional cardiopulmonary resuscitation (CPR) alone does not achieve return of spontaneous circulation, extracorporeal CPR is attempted to restore perfusion and improve outcomes. Considering the contrasting findings of recent studies, we conducted a meta-analysis of randomized controlled trials to ascertain the effect of extracorporeal CPR on survival and neurological outcome.

METHODS

Pubmed via MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials were searched up to February 3, 2023, for randomized controlled trials comparing extracorporeal CPR versus conventional CPR in adults with refractory out-of-hospital cardiac arrest. Survival with a favorable neurological outcome at the longest follow-up available was the primary outcome.

RESULTS

Among four randomized controlled trials included, extracorporeal CPR compared with conventional CPR increased survival with favorable neurological outcome at the longest follow-up available for all rhythms (59/220 [27%] vs. 39/213 [18%]; OR = 1.72; 95% CI, 1.09-2.70; p = 0.02; I²  = 26%; number needed to treat of 9), for initial shockable rhythms only (55/164 [34%] vs. 38/165 [23%]; OR = 1.90; 95% CI, 1.16-3.13; p = 0.01; I²  = 23%; number needed to treat of 7), and at hospital discharge or 30 days (55/220 [25%] vs. 34/212 [16%]; OR = 1.82; 95% CI, 1.13-2.92; p = 0.01; I²  = 0.0%). Overall survival at the longest follow-up available was similar (61/220 [25%] vs. 34/212 [16%]; OR = 1.82; 95% CI, 1.13-2.92; p = 0.59; I²  = 58%).

CONCLUSIONS

Extracorporeal CPR compared with conventional CPR increased survival with favorable neurological outcome in adults with refractory out-of-hospital cardiac arrest, especially when the initial rhythm was shockable.

REVIEW REGISTRATION

PROSPERO CRD42023396482.

Clinical trials of stem cell-based therapies for pediatric diseases: a comprehensive analysis of trials registered on ClinicalTrials.gov and the ICTRP portal site

BACKGROUND

Research on clinical trials that employ stem cells to treat children's diseases is limited. The clinical trial registry database provides a unique window to us to get known about clinical trial researches with different statuses. However, few studies aimed to perform a comprehensive and thorough analysis of those registered trials in the aforementioned field based on ClinicalTrials.gov and the ICTRP portal site.

METHODS

Our study covered the clinical researches about stem cell therapy enrolling subjects aged under 18 years old registered on ClinicalTrials.gov and WHO ICTRP before May 18, 2021. A cross-sectional study was implemented to comprehensively describe and analyze the included trials that met the criteria. Results were available on ClinicalTrials.gov, and publications related to the included trials were identified. All analyses were performed utilizing the SPSS 25.0 software.

RESULTS

Eventually, 202 clinical trials were included and evaluated. The participant number of trials tended to be small; 71.3% were enrolled < 50. And 93.5% of the subjects were without gender restrictions. Till May 2020, 112 trials had been preliminary completed, of which only 39 trials had published papers or uploaded results. Most (73.6%) of 186 interventional trials were in phase 1 and phase 2, where 131 (70.4%) trials were conducted without masking, and 26.3% trials were randomized; 55.4% trials were performed single group assignment. Of 16 observational trials, case-only/series took up 37.5%. Hematopoietic stem cells (37.1%) and mesenchymal stem cells (36.1%) were mostly employed, while umbilical cord blood (UCB)-derived cells (24.3%) and bone marrow (BM)-derived cells (20.8%) were the major sources.

CONCLUSIONS

This study provided an overall picture of utilizing stem cells for treatment and management of childhood diseases. Since clinical trials in this area are insufficient in quantity and quality, there is an urgent need of larger, better-designed trials. Increased investment in clinical research of stem cell treatment products should be carried out to achieve the transformation of results as soon as possible. Moreover, it is important to optimize the management of the registration platform and shorten the time it takes for research results to be published.

Methodological Quality and Risk of Bias Assessment of Cardiovascular Disease Research: Analysis of Randomized Controlled Trials Published in 2017

Background

All randomized-controlled trials (RCTs) are required to follow high methodological standards. In this study, we aimed to assess the methodological quality of published cardiovascular clinical research trials in a representative sample of RCTs published in 2017.

Methods

Cochrane Central Register of Controlled Trials was used to identify cardiovascular clinical research trials with adult participants published in 2017. Overall, 250 (10%) RCTs were randomly selected from a total of 2,419 studies. Data on general trial characteristics were extracted and the risk of bias (RoB) was determined.

Results

Overall, 86% of RCTs have reported at least one statistically significant result, with the primary outcome significant in 69%, treatment favored in 55%, and adverse events reported in 68%. Less than one-third (29%) of trials were overall low RoB, while the other two-thirds were rated unclear (40%) or with high RoB (31%). Sequence generation, allocation concealment, and selective reporting were the domains most often rated with high RoB. Drug trials were more likely to have low RoB than non-drug trials. Significant differences were found in RoB for the allocation concealment and blinding of participants and personnel between industry-funded and non-industry-funded trials, with industry-funded trials more often rated at low RoB.

Conclusion

Almost two-thirds of RCTs in the field of cardiovascular disease (CVD) research, were at high or unclear RoB, indicating a need for more rigorous trial planning and conduct. Prospective trial registration is a factor predicting a lower risk of bias.

Efficacy and safety of IL-6 inhibitors in patients with COVID-19 pneumonia: a systematic review and meta-analysis of multicentre, randomized trials

PURPOSE

COVID-19 is characterized by dysregulated immune response, respiratory failure and a relevant mortality rate among hospitalized patients. Interleukin-6 (IL-6) is involved in COVID-19-associated cytokine storm, and several trials investigated whether its inhibition could improve patients' outcome. We performed a meta-analysis of randomized trials (RCT) to test this hypothesis.

MATERIALS AND METHODS

Two independent investigators searched PubMed, Scopus, ClnicalTrials.gov and medRxiv up to September 1st, 2021. Inclusion criteria were: administration of tocilizumab or sarilumab; COVID-19 adult patients with pneumonia; and being a RCT. Primary outcome was mortality at the longest follow-up. Secondary outcomes included intubation rate and incidence of adverse events. Two independent investigators extracted data from eligible trials.

RESULTS

Of the 763 studies assessed, 15 RCTs were included (9,320 patients), all were multicentre, and the majority open-label vs standard treatment. IL-6 inhibitors were associated with reduced all-cause mortality at the longest follow-up (1315/5,380 [24.4%] in the IL-6 inhibitors group versus 1080/3,814 [28.3%] in the control group, RR = 0.90; 95% CI 0.84 to 0.96; p for effect = 0.003, I2 = 0%, with 13 studies included), with reduction in 28/30-day mortality and intubation rates, and with no increase in adverse events and secondary infections.

CONCLUSION

IL-6 inhibitors reduced longest follow-up mortality and intubation in COVID-19 patients. Findings need to be confirmed in high-quality RCTs.

Vasopressin Versus Norepinephrine for the Management of Septic Shock in Cancer Patients: The VANCS II Randomized Clinical Trial

OBJECTIVES

Previous trials suggest that vasopressin may improve outcomes in patients with vasodilatory shock. The aim of this study was to evaluate whether vasopressin could be superior to norepinephrine to improve outcomes in cancer patients with septic shock.

DESIGN

Single-center, randomized, double-blind clinical trial, and meta-analysis of randomized trials.

SETTING

ICU of a tertiary care hospital.

PATIENTS

Two-hundred fifty patients 18 years old or older with cancer and septic shock.

INTERVENTIONS

Patients were assigned to either vasopressin or norepinephrine as first-line vasopressor therapy. An updated meta-analysis was also conducted including randomized trials published until October 2018.

MEASUREMENTS AND MAIN RESULTS

The primary outcome was all-cause mortality at 28 days after randomization. Prespecified secondary outcomes included 90-days all-cause mortality rate; number of days alive and free of advanced organ support at day 28; and Sequential Organ Failure Assessment score 24 hours and 96 hours after randomization. We also measure the prevalence of adverse effects in 28 days. A total of 250 patients were randomized. The primary outcome was observed in 71 patients (56.8%) in the vasopressin group and 66 patients (52.8%) in the norepinephrine group (p = 0.52). There were no significant differences in 90-day mortality (90 patients [72.0%] and 94 patients [75.2%], respectively; p = 0.56), number of days alive and free of advanced organ support, adverse events, or Sequential Organ Failure Assessment score.

CONCLUSIONS

In cancer patients with septic shock, vasopressin as first-line vasopressor therapy was not superior to norepinephrine in reducing 28-day mortality rate.

Long-term outcome of perioperative low cardiac output syndrome in cardiac surgery: 1-year results of a multicenter randomized trial

PURPOSE

Perioperative myocardial dysfunction occurs frequently in cardiac surgery, and is a risk factor for morbidity and mortality. Levosimendan has been suggested to reduce mortality of patients with perioperative myocardial dysfunction. However, long-term outcome data on its efficacy in cardiac surgery are lacking.

MATERIALS AND METHODS

Cardiac surgery patients with perioperative myocardial dysfunction were randomized to levosimendan or placebo, in addition to standard inotropic care. One-year mortality data were collected.

RESULTS

We randomized 506 patients (248 to levosimendan 258 to placebo). At 1-year follow-up, 41 patients (16.5%) died in the levosimendan group, while 47 (18.3%) died in the placebo group (absolute risk difference -1.8; 95% CI -8.4 to 4.9; P = .60). Female sex, history of chronic obstructive pulmonary disease, previous myocardial infarction, serum creatinine, hematocrit, mean arterial pressure, and duration of cardiopulmonary bypass were independently associated with 1-year mortality.

CONCLUSIONS

Levosimendan administration does not improve 1-year survival in cardiac surgery patients with perioperative myocardial dysfunction. One-year mortality in these patients is 17%. Six predictive factors for long-term mortality were identified.

STUDY REGISTRATION NUMBER

NCT00994825 (ClinicalTrials.gov).

Adrenergic Downregulation in Critical Care: Molecular Mechanisms and Therapeutic Evidence

Catecholamines remain the mainstay of therapy for acute cardiovascular dysfunction. However, adrenergic receptors quickly undergo desensitization and downregulation after prolonged stimulation. Moreover, prolonged exposure to high circulating catecholamines levels is associated with several adverse effects on different organ systems. Unfortunately, in critically ill patients, adrenergic downregulation translates into progressive reduction of cardiovascular response to exogenous catecholamine administration, leading to refractory shock. Accordingly, there has been a growing interest in recent years toward use of noncatecholaminergic inotropes and vasopressors. Several studies investigating a wide variety of catecholamine-sparing strategies (eg, levosimendan, vasopressin, β-blockers, steroids, and use of mechanical circulatory support) have been published recently. Use of these agents was associated with improvement in hemodynamics and decreased catecholamine use but without a clear beneficial effect on major clinical outcomes. Accordingly, additional research is needed to define the optimal management of catecholamine-resistant shock.