Background: Myoglobin is an important biomarker for monitoring critically ill patients. However, the relationship between its dynamic changes and prognosis remains unclear.Methods: We retrospectively enrolled 11,218 critically ill patients from a general and surgical intensive care unit (ICU) of a tertiary hospital between June 2016 and May 2020. Patients with acute cardiovascular events, cardiac and major vascular surgeries, and rhabdomyolysis were excluded. To investigate the early myoglobin distribution, the critically ill patients were stratified according to the highest myoglobin level within 48 h after ICU admission. Based on this, the critically ill patients with more than three measurements within 1 week after ICU admission were included, and latent class trajectory modeling was used to classify the patients. The characteristics and outcomes were compared among groups. Sensitivity analysis was performed to exclude patients who had died within 72 h after ICU admission. Restricted mean survival time regression model based on pseudo values was used to determine the 28-day relative changes in survival time among latent classes. The primary outcome was evaluated with comparison of in-hospital mortality among each Trajectory group, and the secondary outcome was 28-day mortality.Results: Of 6,872 critically ill patients, 3,886 (56.5%) had an elevated myoglobin level (≥150 ng/mL) at admission to ICU, and the in-hospital mortality significantly increased when myoglobin level exceeded 1,000 μg/mL. In LCTM, 2,448 patients were unsupervisedly divided into four groups, including the steady group (n = 1,606, 65.6%), the gradually decreasing group (n = 523, 21.4%), the slowly rising group (n = 272, 11.1%), and the rapidly rising group (n = 47, 1.9%). The rapidly rising group had the largest proportion of sepsis (59.6%), the highest median Sequential Organ Failure Assessment (SOFA) score (10), and the highest in-hospital mortality (74.5%). Sensitivity analysis confirmed that 98.2% of the patients were classified into the same group as in the original model. Compared with the steady group, the rapidly rising group and the slowly rising group were significantly related to the reduction in 28-day survival time (β = −12.08; 95% CI −15.30 to −8.86; β = −4.25, 95% CI −5.54 to −2.97, respectively).Conclusion: Elevated myoglobin level is common in critically ill patients admitted to the ICU. Dynamic monitoring of myoglobin levels offers benefit for the prognosis assessment of critically ill patients.

While endotyping approaches have enhanced precision immunotherapy in sepsis, their temporal instability limits consistent clinical application. To overcome this challenge, the current study utilizes longitudinal immune markers to derive clinically relevant classifications. This study included three cohorts of 3,223 adult septic patients with at least three measurements of two readily available longitudinal immune markers, C-reactive protein (CRP) and absolute lymphocyte count (ALC), within four days following ICU admission. Group-based multi-trajectory modeling was used to cluster sepsis patients based on the dynamic changes of CRP and ALC to identify potential immune subgroups. Comparisons of clinical characteristics, hospital mortality, and persistent inflammation immunosuppression catabolism syndrome (PICS) incidence were made across the derived subgroups. We further characterized the immune-specific properties of each subgroup using 28 immune markers. Based on the optimal classification, 471 sepsis patients in the derivation cohort were categorized into three subgroups: immune homeostasis subgroup (n = 39, 8.3%), immunosuppression subgroup (n = 180, 38.2%), and immune imbalance subgroup (n = 252, 53.5%). This classification remained robust upon validation in both internal (n = 2,527) and external (n = 225) cohorts. Differences in clinical profiles were observed in these subgroups: the immune homeostasis subgroup had the mildest disease severity with the lowest rates of PICS and mortality; the immunosuppression subgroup featured more chronic comorbidities, longer hospital stays, and higher mortality; while the immune imbalance subgroup exhibited the most critical condition, with more complications, longer ICU stays, and the highest incidence of PICS and mortality. Immune features revealed distinct subtype properties: the immune homeostasis subgroup exhibited inflammatory resolution and near-normal immunity; the immunosuppression subgroup characterized by a general reduction in lymphocyte subsets, persistent early T-cell activation, and the highest degree of T cell inhibition; and the immune imbalance subgroup showed a cytokine storm alongside the most severely impaired innate and adaptive immunity, as indicated by markedly low monocyte human leukocyte antigen-DR (mHLA-DR) expression and deficient late T cell activation. This study presents a practical immunological classification for sepsis based on the longitudinal dynamics of two immune markers. These immune subtypes complement existing consensus endotypes and provide a simple, clinically actionable approach particularly applicable in resource-limited settings.

Background: Skeletal muscle is an important organ strongly associated with prognosis in critically ill patients. 60-day mortality represents a key endpoint for evaluating the transitional phase from ICU survival to functional recovery, yet the association between ultrasound-derive muscle indices at ICU admission and 60-day mortality remains unclear. Methods: This dual-center, prospective observational study was performed from January to December 2024. Four ultrasound indices of muscle quantity [thickness and cross-sectional area of the rectus femoris (RF-TH and RF-CSA), thickness of the vastus intermedius (VI-TH), thickness of the quadriceps femoris (QF-TH)], and one index of quality (tibialis anterior pennation angle, TA-PA) were assessed within 24 h of ICU admission. The primary endpoint was 60-day all-cause mortality. To identify predictive factors, multivariable logistic regression analysis was employed. Additionally, a predictive nomogram model was developed. Results: A total of 247 critically ill adult patients were included, with a median age of 61.0 years (51.0–72.0), including 171 males (69.20%). During 60-day follow-up, 53 patients (21.50%) died. Compared with the survivors, the non-survivors exhibited significantly lower RF-TH (0.54 [0.43–0.70] vs. 0.64 [0.48–0.85]cm; P = 0.022), VI-TH (0.64 [0.47–0.86] vs. 0.77 [0.64–1.04]cm; P = 0.002), QF-TH (1.32 [0.96–1.63] vs. 1.48 [1.24–1.97]cm; P =0.005) and TA-PA (7.08[5.63–8.48] vs. 7.94[6.62–9.32]; P =0.002). Among them, TA-PA was identified as an independent predictor of 60-day mortality (β = −0.216, P = 0.035). TA-PA, in conjunction with APACHE II score and prealbumin level, constructed a predictive nomogram, with a consistency index (C-index) of 0.785 (95%CI: 0.728–0.834). Calibration assessed by Spiegelhalter Z -test showed P > 0.05 indicating adequate calibration for the predicted and observed models. Decision curve analysis (DCA) confirmed that the nomogram prediction model had good clinical benefits. Internal validation demonstrated stable model performance, with a concordance statistic (C-index) of 0.785. Compared to the ROC curve based solely on APACHE II score, the nomogram exhibited significantly higher area under the curve (AUC) (0.785, 95%CI: 0.728–0.834 vs. 0.726, 95%CI: 0.666–0.781, P = 0.023). Conclusions: Lower TA-PA at ICU admission is an independent predictor of 60-day mortality. Incorporating this ultrasound-derived muscle quality index with APACHE II score and prealbumin level may improve early risk stratification in critically ill patients.

Background The performance of muscular ultrasound in diagnosing intensive care unit (ICU)-acquired weakness (ICUAW) is debated. We conducted this systematic review and meta-analysis to assess the diagnostic efficacy of muscular ultrasound in ICUAW. Methods Three researchers independently searched PubMed, Web of Science, Embase, Cochrane library, CNKI, VIP and Wanfang databases for articles published before May 2023. The Quality Assessment of Diagnostic Accuracy Studies-2 tool was employed to evaluate the methodological quality of the studies. A random-effects model was utilized to drive the summary estimates of sensitivity, specificity, and diagnostic odds ratio (DOR) with 95% confidence interval (CI), and summary receiver operating characteristic (SROC) curve was estimated. Additionally, a Fagan nomogram was constructed to calculate the post-test probabilities. Sources of heterogeneity were explored by subgroup analysis and meta-regression. Results This meta-analysis comprised nine prospective studies involving 485 participants, of whom 207 (42.68%) were diagnosed as ICUAW. Overall, the muscular ultrasound exhibited good performance for diagnosing ICUAW, with the area of SROC curve of 0.84 (95%CI 0.81–0.87), sensitivity of 0.76 (95%CI 0.70–0.82), specificity of 0.79 (95%CI 0.73–0.83), and DOR of 11.61 (95%CI 7.43–18.13). The included studies exhibited heterogeneity. Upon subgroup analysis, rectus femoris exhibited significantly superior discriminatory ability in identifying ICUAW when compared to the non-rectus femoris, with higher specificity (0.84 [95%CI 0.76–0.90] versus 0.71 [95%CI 0.64–0.77], p = 0.04) and SROC (0.89 [95%CI 0.86–0.91] versus 0.76 [95%CI 0.72–0.79], p < 0.01). Moreover, cross-sectional area was more effective than thickness, with higher specificity (0.84 [95%CI 0.77–0.89] versus 0.74 [95%CI 0.68–0.79], p = 0.02) and SROC (0.85 [95%CI 0.82–0.88] versus 0.76 [95%CI 0.72–0.80], p < 0.01). Furthermore, the integrated analysis of these two indicators revealed that the cross-sectional area of rectus femoris was statistically superior to the thickness of rectus femoris, with higher SROC (0.87 [95%CI 0.83–0.89] versus 0.80 [95%CI 0.76–0.83], p < 0.01). Conclusion Muscular ultrasound has potential to be a reliable tool for ICUAW diagnosis. Comparing to alternative indices, the cross-sectional area of the rectus femoris exhibits superior diagnostic efficacy and may be considered as a valuable parameter for clinical application.