Assessment of Sleep in Ventilator-Supported Critically Ill Patients

Objectives:

In critically ill patients, sleep derangements are reported to be severe using Rechtschaffen and Kales (R&K) methodology; however, whether such methodology can reliably assess sleep during critical illness is unknown. We set out to determine the reproducibility of 4 different sleep-assessment methods (3 manual and 1 computer-based) for ventilator-supported critically ill patients and also to quantify the extent to which the reproducibility of the manual methods for measuring sleep differed between critically ill and ambulatory (control) patients.

Design:

Observational methodologic study.

Setting:

Academic center.

Patients:

Critically ill patients receiving mechanical ventilation and age-matched controls underwent polysomnography.

Interventions:

None.

Measurements and Results:

Reproducibility for the computer-based method (spectral analysis of electroencephalography [EEG]) was better than that for the manual methods: R&K methodology and sleep-wakefulness organization pattern (P = 0.03). In critically ill patients, the proportion of misclassifications for measurements using spectral analysis, sleep-wakefulness organization pattern, and R&K methodology were 0%, 36%, and 53%, respectively (P < 0.0001). The EEG pattern of burst suppression was not observed. Interobserver and intraobserver reliability of the manual sleep-assessment methods for critically ill patients (κ = 0.52 ± 0.23) was worse than that for control patients (κ = 0.89 ± 0.13; P = 0.03). In critically ill patients, the overall reliability of the R&K methodology was relatively low for assessing sleep (κ = 0.19), but detection of rapid eye movement sleep revealed good agreement (κ = 0.70).

Conclusions:

Reproducibility for spectral analysis of EEG was better than that for the manual methods: R&K methodology and sleep-wakefulness organization pattern. For assessment of sleep in critically ill patients, the use of spectral analysis, sleep-wakefulness organization state, or rapid eye movement sleep alone may be preferred over the R&K methodology.

Citation:

Ambrogio C; Koebnick J; Quan SF; Ranieri VM; Parthasarathy S. Assessment of sleep in ventilator-supported critically ill patients. SLEEP 2008;31(11):1559–1568.     

The Role of NK Cells and NK Cell Receptors inAutoimmune Disease

Natural killer (NK) cells are the first line of defense against infection and transformation. Additionally, NK cells can play seemingly opposite roles in autoimmune disease. Here, we summarize the functions of NK cells as both regulators and inducers of autoimmune disease. The role NK cells play depends on which cells become targets for NK cell attack. The activity of NK cells is controlled by inhibitory receptors specific for MHC Class I molecules, and by activating receptors with diverse specificities. The ligands for both activating and inhibitory receptors are present on potential target cells. It is the balance in expression of these different ligands that determines NK cell activation and therefore whether the cell becomes a target for NK cell-mediated killing. We further discuss the roles of NK cell receptors and their ligands in autoimmune disease.     

Clinical Impact of Nosocomial Klebsiella Bacteremia in Critically Ill Patients

In order to determine the clinical impact of Klebsiella bacteremia on critically ill patients, a matched cohort study was conducted between January 1992 and December 2000. During the study period, all intensive care unit (ICU) patients with nosocomial Klebsiella bacteremia were defined as cases (n=52), but two of these patients were excluded from the matched cohort due to incomplete medical records. The remaining 50 patients were matched at a ratio of 1:2 with control patients (n=100) on the basis of the APACHE II severity of disease classification system. Patients with Klebsiella bacteremia experienced acute renal failure and hemodynamic instability more often than controls. They also had a longer ICU stay and longer ventilator dependence. In-hospital mortality rates for cases and controls were nearly equal (36% vs. 37%, respectively; P=0.905). In conclusion, after adjusting accurately for severity of underlying disease and acute illness, no difference in mortality was found between ICU patients with Klebsiella bacteremia and their matched control subjects. Electronic Publication     

Dysregulated Serum MicroRNA Expression Profile and Potential Biomarkers in Hepatitis C Virus-infected Patients

Objectives: Circulating microRNAs (miRNAs) play critical roles in pathogen-host interactions. Aberrant miRNA expression profiles might have specific characteristics for virus strains, and could serve as noninvasive biomarkers for screening and diagnosing infectious diseases. In this study, we aimed to find new potential miRNA biomarkers of hepatitis C virus (HCV) infection.Methods: Expression levels of broad-spectrum miRNAs in serum samples from 10 patients with HCV viremia and 10 healthy volunteers were analyzed using miRNA PCR arrays. Subsequently, the differential expression of four selected miRNAs (miR-122, miR-134, miR-424-3p, and miR-629-5p) was verified by qRT-PCR in the serum of 39 patients compared with that in 29 healthy controls. Receiver operating characteristic (ROC) curve analysis was performed to evaluate their potential for the diagnosis of HCV infection.Results: miRNA PCR array assays revealed differential expression of 106 miRNAs in sera of HCV patients compared with that in healthy controls. Serum hsa-miR-122, miR-134, miR-424-3p, and miR-629-5p were well identified. The ROC curves showed that miR-122, miR-134, miR-424-3p, and miR-629-5p could distinguish HCV patients with preferable sensitivity and specificity. In addition, Correlation analysis indicated serum miR-122 expression was positive correlation with ALT/AST levels. Functional analysis of target proteins of these miRNAs indicated the involvement of viral replication, inflammation, and cell proliferation.Conclusion: HCV patients have a broad ''fingerprint'' profile with dysregulated serum miRNAs compared with that in healthy controls. Among these, serum hsa-miR-122, miR-134, miR-424-3p, and miR-629-5p are identified as promising indication factors of the serum miRNA profile of HCV infection. Particularly, miR-122 could be one of serum biomarkers for early pathological process of HCV. However, more miRNA biomarkers and biological functions of these miRNAs require further investigation.     

肠内营养在重症患者中的应用时机研究

肠内营养支持符合生理,具有预防黏膜萎缩,维持肠道结构完整性等优点,是重症患者营养支持的首选途径遥但对于不 能控制的休克尧严重烧伤尧上消化道出血尧消化功能障碍等患者,早期肠内营养支持的优势及并发症存在争议遥本文就此问题总 结了肠内营养的应用时机,从而为此类患者肠内营养的实施提供理论支持遥     

The Synergy of ‐260T T CD14 and ‐308GG TNF‐α Genotypes in Survival of Critically Ill Patients

Literature suggests that the analysis of several polymorphic genetic markers is more informative than the analysis of a single polymorphism. In this study, we tested whether the shared inheritance of TLR2 and TLR4 and TNF‐α allelic variants may act in synergy with ‐260C>T CD14 SNP on the outcome from critical conditions. We monitored 524 critically ill patients from South Brazilian, daily from the ICU admission to their discharge from hospital, or death. Our results revealed that TLR2, TLR4 or TNF‐α SNPs alone did not show a significant role in the outcome from critical illness. However, when we performed a combined analysis with the CD14 inheritance, we detected a significant higher survivor rate in ‐260TT CD14/‐308GG TNF‐α individuals (P = 0.037). In the adjusted analysis including the main clinical predictors to mortality, we observed that ‐260TT/‐308GG double‐genotype was a significant protective factor towards survival (P = 0.046). An increased probability for survival of ‐260TT/‐308GG was also observed by ‘pathway genetic load’ analysis (unweighted: P = 0.041; weighted: P = 0.036). When we applied a hazard function analysis with the ‐260TT/‐308GG variable as a discriminating factor, ‐260TT/‐308GG patients group had, in fact, a higher survivor rate (P = 0.024). Connected to the beneficial effect of ‐260TT CD14, the ‐308GG TNF‐α genotype was protective against the reported over expression of TNF‐α caused by ‐308A rare allele. Results support the hypothesis that the interaction between ‐260C>T CD14 and ‐308G>A TNF‐α functional SNPs may be synergistically influencing the outcome of critically ill patients.     

Dissemination of Acinetobacter nosocomialis Clone among Critically Ill Patients and the Environment

We examined the environmental dissemination of Acinetobacter nosocomialis multilocus sequence typing clonal complex 260/71 in Rio de Janeiro, Brazil, including water from a dam and food samples. The increasing use of sequence based methods has demonstrated a large, previously unpredicted, dissemination of bacteria that may serve as opportunistic pathogens.     

Pharmacological and Mechanical Thromboprophylaxis in Critically Ill Patients: a Network Meta-Analysis of 12 Trials

Thromboprophylaxis for venous thromboembolism is widely used in critically ill patients. However, only limited evidence exists regarding the efficacy and safety of the various thromboprophylaxis techniques, especially mechanical thromboprophylaxis. Therefore, we performed meta-analysis of randomized controlled trials (RCTs) that compared the overall incidence of deep vein thrombosis (DVT) for between unfractionated heparin (UFH), low-molecular-weight heparin (LMWH), and intermittent pneumatic compression (IPC) in critically ill patients. A Bayesian random effects model for multiple treatment comparisons was constructed. The primary outcome measure was the overall incidence of DVT at the longest follow-up. The secondary outcome measure was the incidence of major bleeding, as defined by the original trials. Our analysis included 8,622 patients from 12 RCTs. The incidence of DVT was significantly lower in patients treated with UFH (OR, 0.45; 95% CrI, 0.22–0.83) or LMWH (OR, 0.38; 95% CrI, 0.18–0.72) than in patients in the control group. IPC was associated with a reduced incidence of DVT compared to the control group, but the effect was not statistically significant (OR, 0.50; 95% CrI, 0.20–1.23). The risk of DVT was similar for patients treated with UFH and LMWH (OR, 1.16; 95% CrI, 0.68–2.11). The risk of major bleeding was similar between the treatment groups in medical critically ill patients and also in critically ill patients with a high risk of bleeding. In critically ill patients, the efficacy of mechanical thromboprophylaxis in reducing the risk of DVT is not as robust as those of pharmacological thromboprophylaxis.