ΔIVC shows limited ability for predicting fluid responsiveness in distinct ventilator settings. In patients with TV ≥8 mL/kg and PEEP ≤5 cm H2O, ΔIVC was an accurate predictor of fluid responsiveness, while in patients with TV <8 mL/kg or PEEP >5 cm H2O, ΔIVC was a poor predictor. Thus, intensivists must be cautious when using ΔIVC.

Autophagy, part of the innate immune defense mechanisms, is activated during the initial phase of septic insult. Previous studies indicated that micro (mi)RNAs are additionally involved in the host response to sepsis; however, the association between miRNAs and autophagy during this process is not fully understood. To study the role of miRNA (miR)-23a in autophagy initiated by sepsis, macrophages treated with lipopolysaccharides, in addition to blood samples from patients, were evaluated for miR-23a expression levels. Cell viability, inflammatory mediators and autophagic markers were investigated following overexpression or inhibition of miR-23a. The results suggested that miR-23a was suppressed subsequent to septic insult, promoting autophagy and suppressing a hyper inflammatory response, leading to enhanced cell viability. A luciferase assay and western blot analysis confirmed ubiquitin-like protein ATG12 to be the target of miR-23a. The present study revealed that the downregulation of miR-23a regulates an inflammatory response during septic insult via autophagy promotion.

Background: Transesophageal echocardiography (TEE) performed by intensivists is increasingly used in critically ill patients. However, TEE is usually not the preferred monitoring tool, especially when transthoracic echocardiography (TTE) appears to have addressed the clinical problems. As a result, it remains largely unknown whether TEE is a clinically valuable replacement or supplement for TTE as a primary tool in evaluating haemodynamic problems in critically ill surgical patients. The purpose of this study was to assess the diagnostic and therapeutic value of TEE instead or in addition to TTE in critically ill surgical patients with hemodynamic instability.Methods: A prospective observational study was conducted. A total of 68 consecutive patients were enrolled from December 2016 to February 2018. TEE was routinely performed in addition to TTE, and the imaging data from TTE and TEE were successively disclosed to two different primary physicians, who reported any resulting changes in management. The two physicians were required to reach a consensus if there was any disagreement. The results of the additional TEE examination were compared with the clinical findings and TTE information. The image quality of TTE views was classified as a good (score 2), suboptimal (score 1) or poor view (score 0). According to the scores of TTE images, the patients were divided into two groups: patients with adequate TTE views (score ≥6) and inadequate TTE views (score <6). Results:The results of additional TEE examination were classified into four categories. TEE failed to provide additional information about the initial diagnosis and therapy (class 1) in 26 patients (38.2%). Of the remaining 42 patients (61.8%), TEE instead or in addition to TTE revealed new findings or led to significant changes in therapy, as TTE supplied inadequate information. TEE used in addition to TTE led to a new diagnosis without therapeutic implications (class 2) in 11 patients (16.2%) and made a major clinical contribution leading to a therapeutic change (class 3) in 23 patients (33.8%). TEE used instead of TTE determined the diagnosis and therapy in 8 patients (11.8%) whose haemodynamic problems could not be addressed by TTE (class 4). In total, TEE had critical therapeutic benefits (class 3 and 4) that was not provided by TTE in 31 patients (45.6%). Of particular concern was that TEE had a higher proportion of therapeutic benefits to patients with inadequate TTE views than those with adequate TTE views (54.3% vs. 27.3%, P=0.036).Conclusions: TEE as a feasible clinical tool is useful for critically ill surgical patients with hemodynamic

Purpose: Respiratory variation in inferior vena cava (ΔIVC) has been extensively studied in predicting fluid responsiveness, but the results are conflicting. We performed a systemic review and meta-analysis of studies aiming at investigating the diagnostic accuracy of ΔIVC in predicting fluid responsiveness. Methods: MEDLINE, EMBASE, Cochrane Database and Web of Science were screened for relevant original and review articles from inception to July 2016. The meta-analysis determined the pooled sensitivity, specificity, diagnostic odds ratio (DOR) and area under the ROC curve (AUROC). In addition, subgroup analyses were performed in mechanically ventilated patients and spontaneously breathing patients. Results: A total of 20 studies involving 635 patients were included. Cutoff values of ΔIVC varied from 12% to 42%, the pooled sensitivity and specificity was 0.68 (0.62-0.75) and 0.80 (0.75-0.85), respectively. The DOR was 14.2 (6.0-33.6) and the AUROC was 0.86 (0.78-0.93). Subgroup analysis showed better diagnostic performance in patients on mechanical ventilation than in spontaneously breathing patients with higher sensitivity (0.75 vs. 0.56), specificity (0.82 vs. 0.78), DOR (22.9 vs. 7.9) and AUROC (0.90 vs. 0.80). The best threshold of ΔIVC in patients on mechanical ventilation was IVC distensibility index (ΔdIVC ≥ 17% ± 4%), compared to IVC collapsibility index (ΔcIVC ≥ 33% ± 12%) in spontaneously breathing patients. Conclusion: ΔIVC is not an accurate predictor of fluid responsiveness in patients with acute circulatory failure. In patients on mechanical ventilation, the predicting ability of ΔIVC was moderate with acceptable sensitivity and specificity; in spontaneously breathing patients, the specificity remains acceptable but its sensitivity is poor.

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