Safeguarding patients in clinical trials with high mortality rates

Clinical Research in Acute Fatal Illness

Clinical research to evaluate the effectiveness of life support systems in acute fatal illness has unique problems of logistics, ethics, and consent. There have been 10 prospective comparative trials of extracorporeal membrane oxygenation in acute fatal respiratory failure, utilizing different study designs. The trial designs were prospective controlled randomized, prospective adaptive randomized, sequential, and matched pairs. The trials were reviewed with regard to logistics, ethics, consent, statistical methods, economics, and impact. The matched pairs method is the best study design for evaluation of life support systems in acute fatal illness.

Trials in adult critical care that show increased mortality of the new intervention: Inevitable or preventable mishaps?

Several promising therapies assessed in the adult critically ill in large, multicenter randomized controlled trials (RCTs) were associated with significantly increased mortality in the intervention arms. Our hypothesis was that there would be wide ranges in sponsorship (industry or not), type(s) of intervention(s), use of DSMBs, presence of interim analyses and early stopping rules, absolute risk increase (ARI), and whether or not adequate prior proof-of-principle Phase II studies were done of RCTs that found increased mortality rates of the intervention compared to control groups. We reviewed RCTs that showed a statistically significant increased mortality rate in the intervention compared to control group(s). We recorded source of sponsorship, sample sizes, types of interventions, mortality rates, ARI (as well as odds ratios, relative risks and number needed to harm), whether there were pre-specified interim analyses and early stopping rules, and whether or not there were prior proof-of-principle (also known as Phase II) RCTs. Ten RCTs (four industry sponsored) of many interventions (high oxygen delivery, diaspirin cross-linked hemoglobin, growth hormone, methylprednisolone, hetastarch, high-frequency oscillation ventilation, intensive insulin, NOS inhibition, and beta-2 adrenergic agonist, TNF-α receptor) included 19,126 patients and were associated with wide ranges of intervention versus control group mortality rates (25.7–59 %, mean 29.9 vs 17–49 %, mean 25 %, respectively) yielding ARIs of 2.6–29 % (mean 5 %). All but two RCTs had pre-specified interim analyses, and seven RCTs were stopped early. All RCTs were preceded by published proof-of-principle RCT(s), two by the same group. Seven interventions (except diaspirin cross-linked hemoglobin and the NOS inhibitor) were available for use clinically at the time of the pivotal RCT. Common, clinically available interventions used in the critically ill were associated with increased mortality in large, pivotal RCTs even though safety was often addressed by interim analyses and early stopping rules.

Does difficulty functioning in the surrogate role equate to vulnerability in critical illness research? Use of path analysis to examine the relationship between difficulty providing substituted judgment and receptivity to critical illness research participation

PURPOSE

Individuals who struggle to provide substitute judgment for the critically ill often find it challenging to engage in decision making for therapeutic interventions. Although essential to the conduct of research, how these individuals respond to requests for clinical trial participation is poorly understood.

METHODS

Survey data collected to examine surrogate attitudes toward research provided the conceptual framework to explore influences on decision making. Path analysis was used to derive the final model (nonlatent, fully recursive, 1 indicator/variable).

RESULTS

Surrogates with list-wise complete records (406) were analyzed. The following variables were not retained in the final model: education, income, religiosity, decision-making experience, discussion of patient's wishes, number of individuals assisting with decision making, trust in care providers, difficulty making decisions, and responsibility for decision making. Being white and having experience making treatment decisions for the patient during the current intensive care unit encounter affected the likelihood the surrogate would permit participation in research positively (parameter estimates, 0.281 and 0.06, respectively). No variable reflecting difficulty functioning in the surrogate role was associated with permitting research participation.

CONCLUSIONS

We were unable to demonstrate a relationship between perceived difficulty in decision making in the surrogate role and receptivity to clinical trial participation.

Surrogate receptivity to participation in critical illness genetic research: aligning research oversight and stakeholder concerns

BACKGROUND

Collection of genetic biospecimens as part of critical illness investigations is increasingly commonplace. Oversight bodies vary in restrictions imposed on genetic research, introducing inconsistencies in study design, potential for sampling bias, and the possibility of being overly prohibitive of this type of research altogether. We undertook this study to better understand whether restrictions on genetic data collection beyond those governing research on cognitively intact subjects reflect the concerns of surrogates for critically ill patients.

METHODS

We analyzed survey data collected from 1,176 patients in nonurgent settings and 437 surrogates representing critically ill adults. Attitudes pertaining to genetic data (familiarity, perceptions, interest in participation, concerns) and demographic information were examined using univariate and multivariate techniques.

RESULTS

We explored differences among respondents who were receptive (1,333) and nonreceptive (280) to genetic sample collection. Whereas factors positively associated with receptivity to research participation were "complete trust" in health-care providers (OR, 2.091; 95% CI, 1.544-2.833), upper income strata (OR, 2.319; 95% CI, 1.308-4.114), viewing genetic research "very positively" (OR, 3.524; 95% CI, 2.122-5.852), and expressing "no worry at all" regarding disclosure of results (OR, 2.505; 95% CI, 1.436-4.369), black race was negatively associated with research participation (OR, 0.410; 95% CI, 0.288-0.585). We could detect no difference in receptivity to genetic sample collection comparing ambulatory patients and surrogates (OR, 0.738; 95% CI, 0.511-1.066).

CONCLUSIONS

Expressing trust in health-care providers and viewing genetic research favorably were associated with increased willingness for study enrollment, while concern regarding breach of confidentiality and black race had the opposite effect. Study setting had no bearing on willingness to participate.

Perspectives of Decisional Surrogates and Patients Regarding Critical Illness Genetic Research

BACKGROUND

Critical illness research is challenging due to disease severity and because patients are frequently incapacitated. Surrogates called upon to provide consent might not accurately represent patient preferences. Though commonplace, genetic data collection adds complexity in this context. We undertook this investigation to understand whether surrogate decision makers would be receptive to permitting participation in a critical illness genetics study and whether their decision making was consistent with that of the patient represented.

METHODS

We invited individuals identified as surrogates for critically ill adults, if required, as well as patients once recovered to participate in a survey designed to understand attitudes about genetic research. Associations between dependent (receptivity to participation, concordance of responses) and independent variables were tested using bivariate and multivariate logistic regression analyses.

RESULTS

Most of the entire surrogate sample (n=439) reported familiarity with research, including genetic research; tended to view research as useful; and were receptive to allowing their family member participate (with 39.6% and 38.1% stating that this would be "very" and "somewhat likely," respectively) even absent direct benefit. Willingness to participate was similar comparing genetic and non-genetic studies (χ² [1,n=439]=0.00127, p=0.972), though respondents expressed worry regarding lack of confidentiality of genetic data. Responses were concordant in 70.8% of the 192 surrogate-patient pairs analyzed. In multivariate analysis, African American race was associated with less receptivity to genetic data collection (p<0.05). No factors associated with concordance of surrogate-patient response were identified.

CONCLUSIONS

Surrogates' receptivity to critical illness research was not influenced by whether the study entailed collection of genetic data. While more than two-thirds of surrogate-patient responses for participation in genetics research were concordant, concerns expressed regarding genetic data often related to breach of confidentiality. Emphasizing safeguards in place to minimize such breeches might prove an effective strategy for enhancing recruitment.

Power and sample size calculations for the Wilcoxon-Mann-Whitney test in the presence of death-censored observations

We consider a clinical trial of a potentially lethal disease in which patients are randomly assigned to two treatment groups and are followed for a fixed period of time; a continuous endpoint is measured at the end of follow-up. For some patients; however, death (or severe disease progression) may preclude measurement of the endpoint. A statistical analysis that includes only patients with endpoint measurements may be biased. An alternative analysis includes all randomized patients, with rank scores assigned to the patients who are available for the endpoint measurement on the basis of the magnitude of their responses and with 'worst-rank' scores assigned to those patients whose death precluded the measurement of the continuous endpoint. The worst-rank scores are worse than all observed rank scores. The treatment effect is then evaluated using the Wilcoxon-Mann-Whitney test. In this paper, we derive closed-form formulae for the power and sample size of the Wilcoxon-Mann-Whitney test when missing measurements of the continuous endpoints because of death are replaced by worst-rank scores. We distinguish two approaches for assigning the worst-rank scores. In the tied worst-rank approach, all deaths are weighted equally, and the worst-rank scores are set to a single value that is worse than all measured responses. In the untied worst-rank approach, the worst-rank scores further rank patients according to their time of death, so that an earlier death is considered worse than a later death, which in turn is worse than all measured responses. In addition, we propose four methods for the implementation of the sample size formulae for a trial with expected early death. We conduct Monte Carlo simulation studies to evaluate the accuracy of our power and sample size formulae and to compare the four sample size estimation methods.

Disruption of CXCR2-mediated MDSC tumor trafficking enhances anti-PD1 efficacy

Suppression of the host's immune system plays a major role in cancer progression. Tumor signaling of programmed death 1 (PD1) on T cells and expansion of myeloid-derived suppressor cells (MDSCs) are major mechanisms of tumor immune escape. We sought to target these pathways in rhabdomyosarcoma (RMS), the most common soft tissue sarcoma of childhood. Murine RMS showed high surface expression of PD-L1, and anti-PD1 prevented tumor growth if initiated early after tumor inoculation; however, delayed anti-PD1 had limited benefit. RMS induced robust expansion of CXCR2(+)CD11b(+)Ly6G(hi) MDSCs, and CXCR2 deficiency prevented CD11b(+)Ly6G(hi) MDSC trafficking to the tumor. When tumor trafficking of MDSCs was inhibited by CXCR2 deficiency, or after anti-CXCR2 monoclonal antibody therapy, delayed anti-PD1 treatment induced significant antitumor effects. Thus, CXCR2(+)CD11b(+)Ly6G(hi) MDSCs mediate local immunosuppression, which limits the efficacy of checkpoint blockade in murine RMS. Human pediatric sarcomas also produce CXCR2 ligands, including CXCL8. Patients with metastatic pediatric sarcomas display elevated serum CXCR2 ligands, and elevated CXCL8 is associated with diminished survival in this population. We conclude that accumulation of MDSCs in the tumor bed limits the efficacy of checkpoint blockade in cancer. We also identify CXCR2 as a novel target for modulating tumor immune escape and present evidence that CXCR2(+)CD11b(+)Ly6G(hi) MDSCs are an important suppressive myeloid subset in pediatric sarcomas. These findings present a translatable strategy to improve the efficacy of checkpoint blockade by preventing trafficking of MDSCs to the tumor site.

Real-time perspectives of surrogate decision-makers regarding critical illness research: findings of focus group participants

OBJECTIVE

We undertook the current investigation to explore how the pressures of serving as a surrogate decision-maker (SDM) for an acutely ill family member influence attitudes regarding clinical investigation.

METHODS

We conducted a prospective study involving SDMs for critically ill patients cared for in the ICUs of two urban hospitals. Measurements included participation in focus groups designed to explore perceptions of ICU care and clinical research. Audiotapes were transcribed and analyzed to identify common patterns and themes using grounded theory. Demographic and clinical data were summarized using standard statistical methods.

RESULTS

Seventy-four SDMs (corresponding to 24% of eligible patients) participated. Most SDMs were women and described long-term relationships with the patients represented. SDMs described their role as "overwhelming," their emotions were accentuated by the fatigue of the ICU experience, and they relied on family members, social contacts, and religion as sources of support. Altruism was reported as a common motivation for potential study participation, a sentiment often strengthened by the critical illness episode. Although research was viewed as optional, some SDMs perceived invitation for research participation as tacit acknowledgment of therapeutic failure. SDMs expressed a preference for observational studies (perceived as low risk) over interventional designs (perceived as higher risk). Trust in the ICU team and the research enterprise seemed tightly linked.

CONCLUSIONS

Despite significant emotional duress, SDMs expressed interest in investigation and described multiple factors motivating participation. Consent processes that minimize the effects of anxiety may be one strategy to enhance recruitment.

Considerations in the construction of an instrument to assess attitudes regarding critical illness gene variation research

Clinical studies conducted in intensive care units are associated with logistical and ethical challenges. Diseases investigated are precipitous and life-threatening, care is highly technological, and patients are often incapacitated and decision-making is provided by surrogates. These investigations increasingly involve collection of genetic data. The manner in which the exigencies of critical illness impact attitudes regarding genetic data collection is unstudied. Given interest in understanding stakeholder preferences as a foundation for the ethical conduct of research, filling this knowledge gap is timely. The conduct of opinion research in the critical care arena is novel. This brief report describes the development of parallel patient/surrogate decision-maker quantitative survey instruments for use in this environment. Future research employing this instrument or a variant of it with diverse populations promises to inform research practices in critical illness gene variation research.

Pharmacoepidemiology of QT-interval prolonging drug administration in critically ill patients

PURPOSE

Commonly prescribed medications produce QT-prolongation and are associated with torsades de pointes in non-acutely ill patients. We examined patterns of QT-prolonging drug use in critically ill individuals.

METHODS

An administrative critical care database was utilized to identify patients receiving drugs associated with QT-interval prolongation or torsades de pointes for > or = 24 hours.

RESULTS

Data from 212 016 individuals collected over a 63-month period was examined to identify 6125 patients (2.9%) receiving QT-interval prolonging drugs. These individuals had a mean (+/-SE) age of 63.0 (+/-0.2) years, were predominately male (55.4%) and Caucasian (84.4%), and were exposed to QT-interval prolonging agents for a mean (+/-SE) 53.1 (+/-0.4)% of their ICU length of stay. Respiratory and cardiovascular illnesses were the most common reasons for ICU admission (17.2, 12.0%, respectively). The most frequently administered agents were amiodarone (23.5%), haloperidol (19.8%), and levofloxacin (19.7%); no other single agent accounted for more than 10% of QT-interval prolonging drugs prescribed. Coadministration of QT-prolonging drugs occurred in 1139 patients (18.6%). These patients had higher ICU mortality rate and longer ICU lengths of stay, compared to patients not receiving coadministered drugs (p < 0.001 for both). For patients receiving coadministered drugs, overlap occurred for 71.4 (+/-0.8)% of the time that the drugs were given. Amiodarone coadministration with antibiotics, haloperidol coadministration with antibiotics, and haloperidol coadministration with amiodarone, comprised 15.2, 13.7, and 9.4%, of all coadministered agents, respectively.

CONCLUSIONS

QT-prolonging drugs were used in a minority of critically ill patients. Prospective evaluation in the ICU environment is necessary to determine whether administration of these agents is associated with adverse cardiac events comparable to those reported in ambulatory patients.

Tumor-induced tolerance and immune suppression by myeloid derived suppressor cells

Emerging evidence indicates that the Achilles' heel of cancer immunotherapies is often the complex interplay of tumor-derived factors and deviant host properties, which involve a wide range of immune elements in the lymphoid and myeloid compartments. Regulatory lymphocytes, tumor-conditioned myeloid-derived suppressor cells (MDSCs), tumor-associated macrophages, and dysfunctional and immature dendritic cells take part in a complex immunoregulatory network. Despite the fact that some mechanisms governing tumor-induced immune tolerance and suppression are starting to be better understood and their complexity dissected, little is known about the diachronic picture of immune tolerance. Based on observations of MDSCs, we present a time-structured and topologically consistent idea of tumor-dependent tolerance progression in tumor-bearing hosts.

Developing alternative strategies for the treatment of traumatic haemorrhagic shock

PURPOSE OF REVIEW

The optimal strategy of stabilizing haemodynamic function in uncontrolled traumatic haemorrhagic shock states is unclear. Although fluid replacement is established in controlled haemorrhagic shock, its use in uncontrolled haemorrhagic shock is controversial, because it may worsen bleeding.

RECENT FINDINGS

In the refractory phase of severe haemorrhagic shock, arginine vasopressin has been shown to be beneficial in selected cases due to an increase in arterial blood pressure, shift of blood away from a subdiaphragmatic bleeding site towards the heart and brain, and decrease in fluid resuscitation requirements. Especially in patients with severe traumatic brain injury, rapid stabilization of cardiocirculatory function is essential to ensure adequate brain perfusion and thus to prevent neurological damage and to improve outcome. In addition, despite wide distribution of highly developed and professional emergency medical systems in western industrialized countries, survival chances of patients with uncontrolled traumatic haemorrhagic shock in the prehospital setting are still poor.

SUMMARY

A multicenter, randomized, controlled, international clinical trial is being initiated to assess the effects of arginine vasopressin (10 IU) vs. saline placebo in prehospital traumatic haemorrhagic shock patients, not responding to standard shock treatment, being managed by helicopter emergency medical services [vasopressin in traumatic haemorrhagic shock (VITRIS.at) study].

Ethical implications of time frames in a randomized controlled trial in acute severe traumatic brain injury

OBJECTIVES

To analyze factors determining the time between injury and study drug administration (SDA) in a randomized controlled trial (RCT) of acute severe traumatic brain injury (TBI) and to discuss the ethical implications.

METHODS

Time frames prior to SDA, differentiated per country, were analyzed in a recently conducted RCT in severe TBI. Per protocol, the time window for SDA was 6 h after injury. We selected patients for whom written proxy consent (PC) was obtained prior to SDA (n=631).

RESULTS

The time between injury and admission to the neurotrauma center (NTC) varied per country from 1.16 to 2.35 h, but CT scan was obtained on average within 1h of admission. The median time between injury and CT scan was within 3 h in all but one country. The broadest time window was observed between CT scan and obtaining required PC (1.71-2.74 h). The median time between injury and PC varied between countries from 3.75 to 5.00 h. After consent had been obtained, almost all patients subsequently received study drug within 1 h. In 85.3% of all cases time between injury and SDA exceeded 4 h, in 60% 5 h.

CONCLUSIONS

The requirement of written PC causes a significant delay in SDA in TBI. With deferred consent, the first dose of an investigational drug could potentially be administered directly after completion of the admission CT scan, which reduce the time to SDA by 50%. We argue that randomization under deferred consent is ethically defendable for emergency research in severe TBI. Recommendations for patient protection are proposed.

'No Time to be Lost!' Ethical considerations on consent for inclusion in emergency pharmacological research in severe traumatic brain injury in the European Union

Severe Traumatic Brain Injury (TBI) remains a major cause of death and disability afflicting mostly young adult males and elderly people, resulting in high economic costs to society. Therapeutic approaches focus on reducing the risk on secondary brain injury. Specific ethical issues pertaining in clinical testing of pharmacological neuroprotective agents in TBI include the emergency nature of the research, the incapacity of the patients to informed consent before inclusion, short therapeutic time windows, and a risk-benefit ratio based on concept that in relation to the severity of the trauma, significant adverse side effects may be acceptable for possible beneficial treatments. Randomized controlled phase III trials investigating the safety and efficacy of agents in TBI with promising benefit, conducted in acute emergency situations with short therapeutic time windows, should allow randomization under deferred consent or waiver of consent. Making progress in knowledge of treatment in acute neurological and other intensive care conditions is only possible if national regulations and legislations allow waiver of consent or deferred consent for clinical trials.

Mechanisms of sepsis and insights from clinical trials

Multiple clinical trials of adjunctive therapy for sepsis and septic shock have been conducted to neutralize bacterial components or to modulate host inflammatory responses to infection but with limited success. Many therapies are only beneficial only in patients with a high severity of illness and have minimal or harmful effects in patients that are less severely ill. Improved measures of severity of illness and discovery of biomarkers to help identify these high-risk patients are needed.

Phosphodiesterase-5 inhibition augments endogenous antitumor immunity by reducing myeloid-derived suppressor cell function

Phosphodiesterase-5 (PDE5) inhibitors (sildenafil, tadalafil, and vardenafil) are agents currently in clinical use for nonmalignant conditions. We report the use of PDE5 inhibitors as modulators of the antitumor immune response. In several mouse tumor models, PDE5 inhibition reverses tumor-induced immunosuppressive mechanisms and enables a measurable antitumor immune response to be generated that substantially delays tumor progression. In particular, sildenafil, down-regulates arginase 1 and nitric oxide synthase-2 expression, thereby reducing the suppressive machinery of CD11b+/Gr-1+ myeloid-derived suppressor cells (MDSCs) recruited by growing tumors. By removing these tumor escape mechanisms, sildenafil enhances intratumoral T cell infiltration and activation, reduces tumor outgrowth, and improves the antitumor efficacy of adoptive T cell therapy. Sildenafil also restores in vitro T cell proliferation of peripheral blood mononuclear cells from multiple myeloma and head and neck cancer patients. In light of the recent data that enzymes mediating MDSC-dependent immunosuppression in mice are active also in humans, these findings demonstrate a potentially novel use of PDE5 inhibitors as adjuncts to tumor-specific immune therapy.

Ethics and research in critical care

BACKGROUND

The past few years have witnessed several controversies regarding the ethics of conducting research involving critically ill patients, and such research is ethically challenging.

DISCUSSION

Research ethics is a changing field, one that is influenced by empirical data, contemporary events, and new ideas regarding aspects of clinical trial design and protection of human subjects. We describe recent thoughts regarding several aspects of research ethics in the critical care context.

CONCLUSION

The ability of the research community to conduct research ethically and to maintain public trust would benefit from heightened awareness to the principles and requirements that govern such research.

Targeting the mechanisms of tumoral immune tolerance with small-molecule inhibitors

Cancer immunotherapy has been predominantly focused on biologically based intervention strategies. However, recent advances in the understanding of tumour-host interactions at the molecular level have revealed targets that might be amenable to intervention with small-molecule inhibitors. In particular, key effectors of tumoral immune escape have been identified that contribute to a dominant toleragenic state that is suspected of limiting the successful implementation of treatment strategies that rely on boosting immune function. Within the context of the pathophysiology of cancer-associated immune tolerance, this Review delineates potential molecular targets for therapeutic intervention and the progress that has been made in developing small-molecule inhibitors.

Genetic research and testing in critical care: surrogates' perspective

OBJECTIVE

Genetic testing is increasingly a component of clinical research in critical illness and has potential for integration into routine care. This study explored the perspectives of surrogate decision-makers (SDMs) for acutely ill patients with respect to social, legal, and ethical aspects of genetic testing.

SETTING

Medical and surgical intensive care units in an urban tertiary care hospital.

INTERVENTION

Questionnaires administered to SDMs for critically ill patients over a 12-month period.

MEASUREMENTS AND MAIN RESULTS

A majority of eligible SDMs participated (117/146; 80.8%). SDMs were more likely to permit genetic testing for purposes of diagnosing a treatable life-threatening disease (114/117; 97.4%) or chronic disease (111/117; 94.9%) than for an untreatable life-threatening illness (95/117; 81.2%) (p < .001). SDMs were receptive to testing to explain familial traits (112/117; 95.7%) or ethnic traits (105/117; 89.7%) (p = .131). SDMs were concerned about potential for economic discrimination, with a majority expressing reluctance to permit testing if employers (93/117; 79.5%), health insurers (90/117; 76.9%), or life insurers (92/117; 78.6%) could access results. There was a greater willingness to allow participation in studies in which data were collected anonymously (90/117; 76.9%) vs. nonanonymously (75/117; 64.1%) (p = .04). Finally, SDMs placed greater trust in universities and nonprofit organizations (107/117; 91.4%) than either the federal government (75/117; 64.1%) or pharmaceutical companies (46/117; 39.3%) to perform genetic research (p < .01).

CONCLUSIONS

SDMs expressed concerns regarding economic discrimination, confidentiality of data, and trust in entities conducting clinical investigation that may represent barriers both to performing studies in which genetic information is collected and to implementation of gene-based technologies in the critical care environment.

La mission des Comités de protection des personnes en France : ni éthique, ni scientifique ?

In France, research on human beings was first organized (and legally authorized) in 1988 by a law (so called Huriet-Séruclat). Since then, the specific mission of research ethics committees (RECs) has been heavily disputed. The legislator explained that the role of RECs is neither ethic nor scientific. It is << to control that the research protocol has been drafted according to the law >>. Of course, this is clearly at odds with the common practice of RECs in France and abroad as well. The assessment of the benefit/risk balance and of the << pertinence >> of the protocol cannot be achieved without a clear understanding of its scientific rationale. Origin of this French << cultural exception >> is to be found in the historic context of the elaboration of the law, back in the mid Eighties.

Beyond randomized, controlled trials

PURPOSE OF REVIEW

Most critical care physicians believe that randomized, controlled trials provide the best available evidence. This review contends that the importance of randomized, controlled trials was overemphasized and that they do not add more to knowledge and practice than physiologic and observational studies. In addition, protection of both patients and proxies may be less adequately ensured during randomized, controlled trials than during observational studies.

RECENT FINDINGS

An analysis of the recent literature on critical care shows that conclusions from randomized, controlled trials are either disputable or do not affect existing practice. In addition, several papers reveal potential conflicts between randomized, controlled trials and ethical principles.

SUMMARY

We may see in the future the twilight of randomized, controlled trials in critically ill patients because scientific, ethical, and sociologic substrata will be progressively lacking as will be funding.

Recommendations for informed consent forms for critical care clinical trials

BACKGROUND

Many subjects enrolled in research studies have a limited understanding of the research to which they consented.

OBJECTIVE

To develop recommendations to enhance comprehensiveness and understanding of informed consent forms used in critical care clinical trials.

DESIGN

Consensus process.

RECOMMENDATIONS

We provide recommendations regarding the U.S. federally required basic and additional elements of informed consent as applied to critical care clinical trials. We also identify issues that investigators need to address, if relevant, in the informed consent forms of critical care clinical trials. These include the description, in understandable language, of complex and detailed experimental protocols that are the focus of the clinical trial, disclosure of death as a risk factor if mortality is an outcome variable, and the identification of who can legally serve as the prospective subject's surrogate. We also offer suggestions to enhance subjects' understanding of informed consent forms.

CONCLUSIONS

The literature on informed consent forms suggest that shorter informed consent forms written at a lower reading level, when read carefully, might provide better subject understanding. Prospective evaluation is needed to determine whether our recommendations enhance the informed consent process.

Les DSMB 2. De l’importance d’un DSMB efficace : exemples d’essais cliniques « à risque »

The DSMB (data safety and monitoring board) takes an increasing role in the monitoring of clinical trials, especially in large multicenter trials conducted in populations at high risk of morbidity or mortality. The DSMB is a an expert committee, independent from the investigators and the sponsor of the trial, which periodically examines the safety data accumulated during progress of the trial and ensures that the benefit/risk ratio remains acceptable for participating patients. A few examples, derived for recent experience of clinical trials conducted in acutely ill patients, illustrate the importance of an efficient and reactive DSMB to monitor patients' safety, especially during large multicenter trials.

Patient care versus research: does clinical research provide individual benefit to patients enrolled in trials?

PURPOSE OF THE REVIEW

Historically, clinical research and patient care have long been intertwined. Until the mid-1970s, physicians in both North America and Europe considered that research on their patients was an integral part of the care that they delivered to them. In the United States, it was after the recommendations of the Belmont report, in 1979, that both medical activities were clearly separated. But, in Europe, the concept of "individual direct benefit from research" is still prevailing in some national legislation.

RECENT FINDINGS

The revision of the Declaration of Helsinki and the implementation of a European directive (in 2001) on clinical research in Member States' national laws have prompted a reappraisal of the distinction of research with and without individual benefit. Several recent articles have shown that this concept is flawed for several reasons: first, the commitment of a physician to his patient is inherently different in these two situations; second, it masks the possible conflict of interest, which can be financial or not; third, it perpetuates the "therapeutic conception" and reduces the obligation for a physician-investigator to implement supplemental procedures aimed at enhancing the safety of study patients.

SUMMARY

The European directive on clinical research, voted on in 2001 and still in the process of being implemented in national laws of the European Union Member States, mandates clarification of these issues. All European investigators are concerned because the framework of regulations governing clinical research will be markedly altered. The replacement of the distinction between research with and without direct benefit by the evaluation of the risk/benefit ratio by ethics committees is one of the most important changes that is due to happen soon.

Fluid resuscitation from severe hemorrhagic shock using diaspirin cross-linked hemoglobin fails to improve pancreatic and renal perfusion

BACKGROUND

Fluid resuscitation from hemorrhagic shock is intended to abolish microcirculatory disorders and to restore adequate tissue oxygenation. Diaspirin cross-linked hemoglobin (DCLHb) is a hemoglobin-based oxygen carrier (HBOC) with vasoconstrictive properties. Therefore, fluid resuscitation from severe hemorrhagic shock using DCLHb was expected to improve perfusion pressure and tissue perfusion of kidneys and pancreas.

METHODS

In 20 anesthetized domestic pigs with an experimentally induced coronary stenosis, shock (mean arterial pressure 45 mmHg) was induced by controlled withdrawal of blood and maintained for 60 min. Fluid resuscitation (replacement of the plasma volume withdrawn during hemorrhage) was performed with either 10% DCLHb (DCLHb group, n = 10) or 8% human serum albumin (HSA) oncotically matched to DCLHb (HSA group, n = 10). Completion of resuscitation was followed by a 60-min observation period. Regional blood flow to the kidneys and the pancreas was measured by use of the radioactive microspheres method at baseline, after shock and 60 min after fluid resuscitation.

RESULTS

All animals (10/10) resuscitated with DCLHb survived the 60-min observation period, while 5/10 control animals died within 20 min due to persisting subendocardial ischemia. In contrast to HSA survivors, pancreas and kidneys of DCLHb-treated animals revealed lower total and regional organ perfusion and regional oxygen delivery. Renal and pancreatic blood flow heterogeneity was higher in the DCLHb group.

CONCLUSION

DCLHb-induced vasoconstriction afforded superior myocardial perfusion, but impaired regional perfusion of the kidneys and the pancreas.

Injury research in the genomic era

With the development of trauma systems, improved resuscitation, and organ system support, survival after severe injury is common, but is often complicated by nosocomial infection and organ failure. These complications are costly, and can lead to death or disability. Although much is known about the pathophysiology of post-traumatic nosocomial infection and organ failure, findings have been limited by our ability to generate and analyse large amounts of experimental and observational data. However, technological advances in nucleic acid and protein analysis, coupled with increased computational capacity, provide an opportunity to characterise the determinants of and the responses to injury and sepsis on a genome-wide scale. New large-scale collaborative efforts aim to investigate the genome for variation (gene polymorphisms), characterise multiple levels of the biological response to injury (transcriptome and proteome), and relate these to clinical phenotypes. In this article, we summarise recent findings and explore where promising new technologies might have the greatest potential for increasing our knowledge. It will now be important to determine how these recent technological advances can be used and integrated with our existing approaches, to reduce death, disability, and the economic consequences of trauma.

[Does clinical research provide any "direct individual benefit"?]

The European Commission and Parliament have promulgated a directive on clinical research (2001/20/CE) in April 2001. Its provisions have to be incorporated in all national laws by May 2004. Accordingly, the French " loi Huriet " (a law passed in 1988 organizing clinical research in France) had to be revised. During the process, it appeared that a key issue was the suppression of a distinction made by this law between research with and without " direct individual benefit ", a French specificity, as the directive recommends rather the assessment of the risk/benefit ratio. In order to harmonize the French legislation with the other European laws, and to suppress a set of provisions which have been repeatedly attacked during the last ten years, the French members of parliament have voted on October 2003 a new law which, among other important modifications, suppress that distinction.

Control group selection in critical care randomized controlled trials evaluating interventional strategies: An ethical assessment*

BACKGROUND

Ethical concern has been raised with critical care randomized controlled trials in which the standard of care reflects a broad range of clinical practices. Commentators have argued that trials without an unrestricted control group, in which standard practices are implemented at the discretion of the attending physician, lack the ability to redefine the standard of care and might expose subjects to excessive harms due to an inability to stop early.

OBJECTIVE

To develop a framework for analyzing control group selection for critical care trials.

METHOD

Ethical analysis.

RESULTS

A key ethical variable in trial design is the extent with which the control group adequately reflects standard care practices. Such a control group might incorporate either the "unrestricted" practices of physicians or a protocol that specifies and restricts the parameters of standard practices. Control group selection should be determined with respect to the following ethical objectives of trial design: 1) clinical value, 2) scientific validity, 3) efficiency and feasibility, and 4) protection of human subjects. Because these objectives may conflict, control group selection will involve trade-offs and compromises. Trials using a protocolized rather than an unrestricted standard care control group will likely have enhanced validity. However, if the protocolized control group lacks representativeness to standard care practices, then trials that use such groups will offer less clinical value and could provide less assurance of protecting subjects compared with trials that use unrestricted control groups. For trials evaluating contrasting strategies that do not adequately represent standard practices, use of a third group that is more representative of standard practices will enhance clinical value and increase the ability to stop early if needed to protect subjects. These advantages might come at the expense of efficiency and feasibility.

CONCLUSION

Weighing and balancing the competing ethical objectives of trial design should be done for each trial.

The effect of waiving consent on enrollment in a sepsis trial

OBJECTIVE

Illustration of the difficulties in approaching critically ill patients for informed consent for inclusion into a randomized controlled trial and the impact of a waiver of consent from the patient's next of kin in the conduction of such studies.

DESIGN

Descriptive survey of the inclusion rates into the Ger-Inf-05 study before and after a waiver of consent from the patient's next of kin.

SETTING

Nineteen intensive care units in France.

PATIENTS

Septic shock patients (n=300) included in a placebo-controlled randomized double-blind study on the efficacy and safety of a 7-day treatment with 50 mg hydrocortisone every 6 h intravenously and 50 microg fludrocortisone every 24 h orally.

INTERVENTION

Introduction, 10 months after the beginning of the study, of a waiver of consent from the patient's next of kin if it was not present at the time of the patient's inclusion.

MEASUREMENTS AND RESULTS

The mean inclusion rate was four patients per month before the introduction of the waiver of consent and increased to 10 patients per month after the study amendment including the waiver of consent. Informed consent was obtained from the patient himself or herself in 10 patients (3%) and from next of kin in 70 patients (23%). For the 220 other patients (74%), the investigators could not contact the responsible relative within the inclusion period.

CONCLUSIONS

Recruitment rate in the Ger-Inf-05 study was clearly improved after the waiver of consent from the patient's next of kin. This probably contributed to the successful completion of the study.

Is the concept of informed consent applicable to clinical research involving critically ill patients?

Informed consent is a process through which patients or their surrogates authorize medical interventions or involvement in research. The concept of informed consent is supported by ethical principles and legal tradition in the United States. It grew in importance during the 20th century because of documented abuse of research subjects, which led to its codification in federal consent requirements for clinical research. For the most part, the concept and the codification are based on a model of competent patients who are capable of informed decision-making and can communicate their wishes. However, most critically ill patients are incompetent and cannot communicate easily. As a result, family members usually must give consent for them. Yet family members frequently are unavailable, and when they are available, they may not know the patient's wishes. Furthermore, family members may not be legally authorized to give consent for research involvement under state law. For these and other reasons, it has been argued that the concept of informed consent is not applicable to clinical research involving the critically ill and that such consent is not necessary in certain circumstances. Yet, for all its inadequacies, the concept of informed consent and the federal consent requirements should be retained because they promote respect for patients and their right of self-determination and because investigator discretion is not adequate. Stronger research oversight may be as important as informed consent in protecting patient welfare.

Blood substitutes

Blood substitutes are solutions intended to replace transfusion of banked red blood cells. Several variations of products based on either hemoglobin (animal or human) or perfluorocarbon emulsions are in advanced stages of clinical development. The need for such products is pressing as shortages of banked blood worsen and awareness of the dangers of blood transfusion increases. Animal and human studies with these cell-free oxygen carriers have led to new concepts of how oxygen is delivered to tissue and how the microcirculation is regulated. Although development of products is exciting and timely, understanding how they function to perfuse and oxygenate tissue could be at least as important. Because cell-free oxygen carriers will perfuse every organ of the body, their effects are far-reaching, and the transition from the laboratory to the bedside can be expected to be slow and deliberate. Comparison of oxygen carriers with more traditional starch-based products provides new insight into the interaction of oxygen transport, microvascular perfusion, and blood volume expansion.