Ethical issues of nosology in disorders of consciousness

The current classification scheme for severe disorders of consciousness (DoC) has several shortcomings. First, there is no consensus on how to incorporate patients with covert consciousness. Second, there is a mismatch between the definitions of severe DoC, based on consciousness, and the diagnosis of these same DoC, which is based on observable motoric responsiveness. Third, current categories are grouped into large heterogeneous syndromes which share phenotype, but do not incorporate underlying pathophysiology. Here we discuss several ethical issues pertaining to the current nosology of severe DoC. We conclude by proposing a revised nosology which addresses these shortcomings.

Similarities in consciousness occurring during sleep and sedation

The subjective experiences of sedation or anaesthesia are underexplored. A recent study by Valli and colleagues (Br J Anaesth 2023; 131: 348-59) found similar frequency and content of recalled experiences after both non-rapid eye movement sleep and target-controlled infusions of propofol or dexmedetomidine titrated to verbal unresponsiveness. The authors find that the phenomenological similarities between consciousness during sleep and sedation mirror their physiological similarities. Intriguingly, in this small sample, conscious experience did not show a dose-dependent response suggesting other factors are important in determining the propensity for consciousness under sedation.

Subjective experiences during dexmedetomidine- or propofol-induced unresponsiveness and non-rapid eye movement sleep in healthy male subjects

BACKGROUND

Anaesthetic-induced unresponsiveness and non-rapid eye movement (NREM) sleep share common neural pathways and neurophysiological features. We hypothesised that these states bear resemblance also at the experiential level.

METHODS

We compared, in a within-subject design, the prevalence and content of experiences in reports obtained after anaesthetic-induced unresponsiveness and NREM sleep. Healthy males (N=39) received dexmedetomidine (n=20) or propofol (n=19) in stepwise doses to induce unresponsiveness. Those rousable were interviewed and left unstimulated, and the procedure was repeated. Finally, the anaesthetic dose was increased 50%, and the participants were interviewed after recovery. The same participants (N=37) were also later interviewed after NREM sleep awakenings.

RESULTS

Most subjects were rousable, with no difference between anaesthetic agents (P=0.480). Lower drug plasma concentrations were associated with being rousable for both dexmedetomidine (P=0.007) and propofol (P=0.002) but not with recall of experiences in either drug group (dexmedetomidine: P=0.543; propofol: P=0.460). Of the 76 and 73 interviews performed after anaesthetic-induced unresponsiveness and NREM sleep, 69.7% and 64.4% included experiences, respectively. Recall did not differ between anaesthetic-induced unresponsiveness and NREM sleep (P=0.581), or between dexmedetomidine and propofol in any of the three awakening rounds (P>0.05). Disconnected dream-like experiences (62.3% vs 51.1%; P=0.418) and memory incorporation of the research setting (88.7% vs 78.7%; P=0.204) were equally often present in anaesthesia and sleep interviews, respectively, whereas awareness, signifying connected consciousness, was rarely reported in either state.

CONCLUSIONS

Anaesthetic-induced unresponsiveness and NREM sleep are characterised by disconnected conscious experiences with corresponding recall frequencies and content.

CLINICAL TRIAL REGISTRATION

Clinical trial registration. This study was part of a larger study registered at ClinicalTrials.gov (NCT01889004).

Pharmacogenetic Study of the Impact of ABCB1 Single Nucleotide Polymorphisms on the Response to Cyclosporine in Psoriasis Patients

Psoriasis is a chronic, T cell-mediated skin disease affecting 2-3% of the Caucasian population. Cyclosporine A is a calcineurin inhibitor that acts selectively on T cells. The cyclosporine A treatment response has been suggested to be modulated by single-nucleotide polymorphisms (SNPs) in the ABCB1 gene. The aim of this research was to evaluate the effect of ABCB1 genetic variants that could affect the response to a cyclosporine treatment in Russian psoriasis patients with the ABCB1 genotype status. The ABCB1 T-129C, G1199A, C1236T, G2677T/A and C3435T SNPs in the 168 patients with psoriasis were genotyped by PCR-RFLP (polymerase chain reaction-restriction fragment length polymorphism) and TaqMan SNP genotyping assays. The ABCB1 C1236T, G2677T/A and C3435T SNPs were significantly associated with a negative response to cyclosporine therapy. A very strong association was evident for the C3435T SNP in the ABCB1 gene in the allele, dominant and recessive models (OR = 2.58, OR = 4.01, OR = 2.50, respectively). ABCB1 C1236T and G2677T/A polymorphisms were significantly associated with a negative response to the cyclosporine therapy in the codominant, dominant and recessive models (p ˂ 0.05). Additionally, the haplotype analysis identified that the TGC haplotype is significantly associated with a negative response to cyclosporine therapy in psoriasis patients (p ˂ 0.05). The current study to the best of our knowledge is the first of its kind to be performed in the Russian population. In conclusion, the present results suggest an association between the ABCB1 genetic variants and unresponsiveness to cyclosporine in the Russian population. Further, larger studies are necessary to confirm our findings and replicate them in various ethnic populations before its implementation in the clinical practice.

Case Report: Behavioral Unresponsiveness in Acute COVID-19 Patients: The Utility of the Motor Behavior Tool-Revised and 18F-FDG PET/CT

Along with the propagation of COVID-19, emerging evidence reveals significant neurological manifestations in severely infected COVID-19 patients. Among these patients admitted to the intensive care unit (ICU), behavioral unresponsiveness may occur frequently, yet, there are still only a few cases reported and with rare descriptions of their motor behavior after pathological awakening. Several hypotheses regarding central lesions in these patients are conceivable. Here, we describe two acute SARS-CoV-2- infected patients who developed neurological symptoms evoking the condition of clinical cognitive motor dissociation (CMD). This diagnosis could be confirmed first by clinical observation of a dissociation between preserved cognitive abilities and lack of initial motor interaction and second, by performing ¹⁸F- FDG PET imaging. Accurate diagnosis led to an appropriate neuro-rehabilitation regimen with long-term neuro-rehabilitation leading to an improved outcome for both patients.

Housing Horses in Individual Boxes Is a Challenge with Regard to Welfare

Horses are mainly housed in individual boxes. This housing system is reported to be highly detrimental with regard to welfare and could trigger the expression of four behavioural indicators of a compromised welfare state: stereotypies, aggressiveness toward humans, unresponsiveness to the environment, and stress-related behaviours. The aim of this study was to identify housing and management factors that could alleviate the detrimental effects of individual boxes on welfare. A total of 187 horses were observed over 50 days by scan sampling. The impact of 12 factors was investigated on the expression of the four behavioural indicators in three different analyses. The results show that the majority of factors tested did not influence the expression of the behavioural indicators. Only three (straw bedding, a window opening onto the external environment, and a reduced quantity of concentrated feed) would have beneficial, although limited, effects. Furthermore, the longer the horses spent in individual boxes, the more likely they were to express unresponsiveness to the environment. To preserve the welfare of horses, it seems necessary to allow free exercise, interactions with conspecifics, and fibre consumption as often as possible, to ensure the satisfaction of the species' behavioural and physiological needs.

Breakthrough Medication in Unresponsive Palliative Care Patients: Indications, Practice, and Efficacy

CONTEXT

An unresponsive patient's need and their response to breakthrough medication is determined by clinical assessment and/or observational measures. How closely these methods match the patient's experience is unknown.

OBJECTIVES

Determine the efficacy and effectiveness of breakthrough medication in unresponsive patients and the perception of patient comfort made by nurses and family.

METHODS

A prospective study of breakthrough medication in unresponsive patients. The Richmond Agitation-Sedation Scale (RASS) and Patient Comfort Score (PCS) were compared with time-matched Bispectral Index (BIS) Scores. The effects of opioid vs. opioid + benzodiazepine breakthroughs and the relation between synchronous nurse and family measurements of the PCS were evaluated. Analysis of variance and paired t-tests were used for BIS analyses and nonparametric Mann-Whitney tests for RASS and PCS.

RESULTS

Significant reductions at 30 and 60 minutes after breakthrough medication were noted for BIS (P < 0.0004), RASS (P = 0.043 and 0.004, respectively), and PCS (P < 0.0004). A direct comparison of the effect of opioid breakthrough medication vs. opioid plus benzodiazepine revealed no significant difference (BIS, P = 0.512; RASS, P = 0.195; PCS, P = 0.119). Of the 157 synchronous nurse and family measures of patient comfort, families rated patient discomfort significantly higher than nurses (P < 0.0004).

CONCLUSION

This study provides additional evidence for the efficacy and effectiveness of breakthrough medication and the merit of observational measures in determining a patient's response. The onset of action is evident at 30 minutes after injection. Family assessment of patient comfort may be more nuanced than that of nurses, and they not uncommonly rate patient discomfort higher than nurses.

Blood group 'A' may have a possible modifier effect on familial Mediterranean fever and blood group '0' may be associated with colchicine resistance

Aim/purpose: Our aim was to investigate the association between blood groups and colchicine resistance in familial Mediterranean fever (FMF) patients.

METHODS

This is a single-center, cross-sectional study. Between January and December 2016, 385 FMF patients were assessed by the Adult and Pediatric Rheumatology outpatient clinics and 297 patients had blood groups (ABO and Rh) results. The patients were grouped into two groups: colchicine-responsive patients (Group CR) and colchicine-unresponsive patients (Group CUR).

RESULTS

Patients with blood group A had 1.5-fold higher FMF compared with non-A blood group (OR: 1.50 [95% CI: 1.11-1.87]), particularly having a Rh (+) blood group (OR: 1.47 [95% CI: 1.13-1.91]). Furthermore, patients with blood group A had a better response to colchicine treatment than non-A blood group; (OR: 2.21 [95% CI: 1.15-4.27]). Patients with blood group O were prominently associated with colchicine resistance.

CONCLUSION

ABO blood phenogroups may be used in combination with other risk factors to identify FMF patients and patients at high risk for colchicine resistance.

Prehospital emergency treatment of palliative care patients with cardiac arrest: a retrolective investigation

BACKGROUND

Today, prehospital emergency medical teams (EMTs) are confronted with emergent situations of cardiac arrest in palliative care patients. However, little is known about the out-of-hospital approach in this situation and the long-term survival rate of this specific patient type. The aim of the present investigation was to provide information about the strategic and therapeutic approach employed by EMTs in outpatient palliative care patients in cardiac arrest.

METHODS

During a period of 2 years, we retrolectively analysed emergency medical calls with regard to palliative care emergency situations dealing with cardiac arrest. We evaluated the numbers of patients who were resuscitated, the prevalence of an advance directive or other end-of-life protocol, the first responder on cardiac arrest, the return of spontaneous circulation (ROSC) and the survival rate.

RESULTS

Eighty-eight palliative care patients in cardiac arrest were analysed. In 19 patients (22%), no resuscitation was started. Paramedics and prehospital emergency physicians began resuscitation in 61 cases (69%) and in 8 cases (9%), respectively. A total of 10 patients (11%) showed a ROSC; none survived after 48 h. Advance directives were available in 43% of cases. The start of resuscitation was independent of the presence of an advance directive or other end-of-life protocol.

CONCLUSIONS

Strategic and therapeutic approaches in outpatient palliative care patients with cardiac arrest differ depending on medical qualification. Although many of these patients do not wish to be resuscitated, resuscitation was started independent of the presence of advance directive. To reduce legal insecurity and to avoid resuscitation and a possible lengthening of the dying process, advance directives and/or "Do not attempt resuscitation" orders should be more readily available and should be adhered to more closely.

Viral immune evasion due to persistence of activated T cells without effector function

We examined the regulation of virus-specific CD8 T cell responses during chronic lymphocytic choriomeningitis virus (LCMV) infection of mice. Our study shows that within the same persistently infected host, different mechanisms can operate to silence antiviral T cell responses; CD8 T cells specific to one dominant viral epitope were deleted, whereas CD8 T cells responding to another dominant epitope persisted indefinitely. These virus-specific CD8 T cells expressed activation markers (CD69(hi), CD44(hi), CD62Llo) and proliferated in vivo but were unable to elaborate any antiviral effector functions. This unresponsive phenotype was more pronounced under conditions of CD4 T cell deficiency, highlighting the importance of CD8- CD4 T cell collaboration in controlling persistent infections. Importantly, in the presence of CD4 T cell help, adequate CD8 effector activity was maintained and the chronic viral infection eventually resolved. The persistence of activated virus-specific CD8 T cells without effector function reveals a novel mechanism for silencing antiviral immune responses and also offers new possibilities for enhancing CD8 T cell immunity in chronically infected hosts.

T helper responsiveness in human Loa loa infection; defective specific proliferation and cytokine production by CD4+ T cells from microfilaraemic subjects compared with amicrofilaraemics

The proliferation and cytokine profiles of peripheral blood mononuclear cells (PBMC) from microfilaraemic (Mf+) subjects infected by Loa loa in response to antigens of several parasitic stages were compared with those from amicrofilaraemic (Mf-) individuals. While a strong lymphoproliferative response and consistent levels of both Th1 (IL-2, interferon-gamma (IFN-gamma)) and Th2 (IL-4, IL-5) type cytokines were observed in response to adult worm (AW) and microfilariae (Mf) antigen in Mf- individuals, Mf+ subjects were characterized by a T cell unresponsiveness, including proliferation, cytokine production and IL-2 mRNA expression. Conversely, T cell responsiveness to mitogens and non-specific antigen were similar in the two endemic populations. Depletion of lymphocyte subpopulations indicated that T CD4+ were mainly involved in the specific cellular response. In contrast to other cytokines, IL-10 was produced in response to all parasitic stages, in both Mf+ and Mf- patients. Neutralization of IL-10 did not restore cytokine production in Mf+ patients, while B7 mRNA expression was similar between Mf+ and Mf- subjects in response to Mf antigen, suggesting that IL-10 was not the only factor responsible for T cell unresponsiveness. Mf+ patients have lower Mf antigen-specific IgG levels compared with Mf-, and there is a significant correlation between Mf antigen-specific antibodies and IL-5 responses. These findings suggest that Mf- status is correlated with T helper responsiveness, including proliferation and production of both Th1- and Th2-type cytokines, whereas Mf+ status is characterized by unresponsiveness of the same cell population, induced and/or maintained by microfilariae.