Intravascular temperature management (IVTM) is widely used for temperature control after cardiac arrest, but its association with IVTM-related venous thromboembolism (VTE) remains clinically important. D-dimer is commonly used for VTE evaluation, although interpretation is challenging after cardiac arrest because coagulation and fibrinolytic abnormalities can elevate D-dimer values. We conducted a single-center retrospective cohort study of out-of-hospital cardiac arrest patients treated with IVTM between August 2021 and August 2024. D-dimer levels were measured daily for 7 days and reported in µg/mL D-dimer units. IVTM-related VTE diagnosed within 10 days after admission was identified from medical records. Delta D-dimer was defined as the increase from each baseline value on Days 1, 2, or 3 to the peak value within 7 days. Among 51 patients, 8 (15.7%) developed IVTM-related VTE; the median time to diagnosis was 5.5 days. Peak D-dimer was higher in patients with IVTM-related VTE than in those without IVTM-related VTE (56.0 vs. 17.4 µg/mL DDU). Delta D-dimer was associated with IVTM-related VTE in adjusted logistic regression models, with adjusted odds ratios ranging from 1.04 to 1.10 per 1 µg/mL increase. In post-cardiac arrest patients undergoing IVTM, increases in D-dimer from early-phase values to peak were associated with IVTM-related VTE. Serial D-dimer assessment may help identify patients who warrant targeted imaging when IVTM-related VTE is clinically suspected.

We report the case of a 70-year-old female with a history of hypothyroidism who presented following an unwitnessed fall with bradycardia and hypothermia. She was found to have myxedema coma complicated by signs of early cardiac tamponade, requiring urgent pericardiocentesis. Myxedema coma is a rare but life-threatening manifestation of severe decompensated hypothyroidism, carrying a high mortality rate despite treatment. It commonly presents with hypothermia and altered mental status and may be precipitated by infection, trauma, medication nonadherence, or cold exposure. Early recognition and prompt treatment with intravenous stress-dose steroids and thyroid hormone replacement are essential to improve outcomes. This case highlights the potentially severe complications of inadequately treated hypothyroidism. It emphasizes the importance of considering cardiac tamponade as a rare but life-threatening consequence of this disease, requiring a high index of suspicion, timely diagnosis, and urgent intervention.

[This corrects the article DOI: 10.7759/cureus.108742.].

Organ preservation remains a critical challenge in transplantation, primarily due to hypothermia-induced oxidative stress and metabolic dysfunction. Here, we report a mitochondria-enriched, cell-free preservation strategy by supplementing standard preservation solutions with freshly isolated mitochondria derived from human induced pluripotent stem cell-mesenchymal stem cells (MSC-mt). MSC-mt retained intact ultrastructure and functional biophysical properties. In vitro, MSC-mt were internalized by hepatocyte- and kidney-derived cells, reduced oxidative stress, preserved ATP levels, and attenuated apoptosis under cold stress. Ex vivo, MSC-mt improved liver preservation in University of Wisconsin (UW) solution, reducing sinusoidal edema, apoptosis, ALT/AST release, MDA accumulation, and oxidative DNA damage while enhancing SOD activity and preserving mitochondrial content. Human-specific mitochondrial signals remained detectable within preserved hepatic tissue. In a warm reoxygenation model, MSC-mt enhanced ATP recovery and reduced tissue injury and oxidative damage following cold storage. In kidneys, MSC-mt provided stronger protection than fibroblast- or adipose-derived mitochondria across both HC-A and UW solutions. Mechanistically, MSC-mt showed higher total and phosphorylated PINK1 levels and greater Parkin co-localization than fibroblast-derived mitochondria, while mitophagy inhibition partially reversed their antioxidant effects. These findings establish MSC-mt as a cell-free mitochondrial strategy for improving hypothermic organ preservation.

IntroductionDeep hypothermia (DH) has been widely adopted for cerebral and visceral protection during pediatric cardiac surgery, but concerns about perioperative complications remain. This meta-analysis aims to evaluate the impact of DH compared to moderate hypothermia (MH) on outcomes in pediatric cardiac surgery patients.MethodsFollowing a PRISMA-compliant systematic search in PubMed, Cochrane, and Embase, eligible studies comparing DH (<22°C) with MH (22-30°C) in pediatric cardiac surgery were assessed. Risk of bias was evaluated using the ROBINS-I tool.ResultsFive comparative studies with 448 patients (250 in the MH group and 198 in the DH group) were included. Baseline characteristics were similar between groups, with the majority of patients undergoing aortic arch repairs. Perioperative variables were also similar, except for cross-clamp time, which was significantly longer in the DH group (p = 0.02), and circulatory arrest was more frequently used in DH patients (p = 0.01). No significant differences were found in overall postoperative complication rates, acute kidney injury, 24-h chest drainage volume, or in-hospital mortality. However, the incidence of early postoperative neurological complications was significantly higher in the DH group (p < 0.001).ConclusionsModerate hypothermia may be associated with a significantly lower incidence of postoperative neurological complications compared to deep hypothermia, while overall in-hospital mortality and morbidity rates remained similar between the two groups. Taken together, these findings support moderate hypothermia with regional perfusion as a clinically feasible and well-tolerated alternative to deep hypothermia in pediatric cardiac surgery.

Inadvertent perioperative hypothermia (IPH), defined as a core temperature below 36 °C, is a common complication of elective procedures under general anesthesia and has traditionally been treated as an anesthetic concern. In medium- and large-volume plastic surgery, including abdominoplasty, large-volume liposuction, combined and postbariatric body contouring, and autologous and microsurgical reconstruction, wide body-surface exposure, cold tumescent solution, prolonged operative time, and combined anesthesia amplify this risk and make it directly relevant to surgical outcomes. This narrative review, structured around the Scale for the Assessment of Narrative Review Articles (SANRA) domains, synthesizes the pathophysiology; the wound-healing, flap, and microsurgical implications most relevant to plastic surgery; the subclinical hemodynamic consequences; the surgical outcomes; and practical prevention strategies for IPH, drawing on searches in PubMed/MEDLINE, Cochrane Library, SciELO, and Embase (1996-2024). Even mild IPH meaningfully increases the risks of surgical site infection, intraoperative bleeding, ischemic cardiac events, and delayed emergence; of particular concern in plastic surgery, it fosters a vasoconstricted, hypoperfused microcirculatory environment that threatens wound edges, random-pattern and pedicled flaps, and microsurgical anastomoses. Postoperative hypothermia is especially frequent after prolonged operations. Prewarming, forced-air warming, and fluid warming substantially reduce IPH incidence. We propose that perioperative normothermia be treated as an auditable institutional quality indicator, shared across the perioperative team, with the plastic surgeon contributing specific, protocol-driven actions.

Objective This study aimed to evaluate the feasibility and temperature stability of low-complexity therapeutic hypothermia (TH) in neonates with moderate-to-severe hypoxic-ischemic encephalopathy (HIE). Study Design Retrospective case series of neonates born at ≥36 weeks of gestation with moderate-to-severe HIE treated with low-complexity TH in a tertiary-level hospital in Peru (2018-2024). Variables included timing of initiation, achievement and maintenance of the target core temperature, duration of hypothermia, and clinical outcomes. Descriptive statistics were used. Results A total of 13 neonates were included (77% male; median gestational age 38 weeks). TH was initiated at a median of 103 min after birth. Within the first 6 hours, 84.6% reached 34°C; however, only 31% maintained a stable core temperature within the target range (33.5-34.5°C) throughout treatment. Median duration of hypothermia was 75 hours. Complications occurred in 23.1% of cases, and overall mortality was 15.4%. Conclusion Low-complexity TH is feasible and allows timely initiation within the neuroprotective window. However, maintaining stable therapeutic temperatures remains a major challenge, which may compromise its potential neuroprotective effectiveness.

Brain monoamine systems regulate a wide spectrum of behaviors. Serotonin (5-HT) is traditionally linked to depression, whereas dopamine (DA) is associated with anhedonia and impaired motivation. The genes for the 5-HT1A receptor (Htr1a) and DRD2 receptor (Drd2) share a common transcription factor, Freud-1, encoded by Cc2d1a. We investigated the effect of hippocampal Cc2d1a/Freud-1 knockdown (via adeno-associated viral construct in vivo) in genetically predisposed to depressive-like behavior ASC (Antidepressants Sensitive Catalepsy) male mice on behavior and on the brain 5-HT and DA systems. Cc2d1a/Freud-1 knockdown, confirmed at both the mRNA and protein levels, led to led to disinhibition of Htr1a and Drd2 expression, reduced immobility time, and decreased the percentage of cataleptic mice in the catalepsy test. It attenuated depressive-like behavior in the forced swim test, improved social interaction in the resident-intruder test, and enhanced spatial memory in the Morris water maze, without affecting anhedonia or anxiety. In experimental animals, 5-HT1A receptor functional activity, assessed by 8-OH-DPAT-induced hypothermia, was increased, whereas 5-HT2A receptor activity, assessed by 25CN-NBOH-induced head-twitches, was decreased. Cc2d1a/Freud-1 knockdown also elevated hippocampal catechol-O-methyltransferase mRNA levels and monoamine oxidase A protein levels, as well as midbrain tryptophan hydroxylase-2 activity. The ratios of DA and 5-HT to their metabolites remained unchanged. Our findings indicate that Cc2d1a/Freud-1 is involved in emotional and social behaviors, likely through modulation of serotonergic signaling and 5-HT receptor function. This study highlights hippocampal Cc2d1a as a potential transcriptional regulator of monoaminergic systems in depression-related phenotypes.

IntroductionGoal-directed perfusion during cardiopulmonary bypass (CPB) has traditionally focused on indexed oxygen delivery (DO2i), yet metabolic behavior during aortic cross-clamping likely reflects a more complex interaction among oxygen delivery, oxygen extraction (O2ER), and temperature-dependent oxygen demand. We aimed to identify temperature-adjusted perfusion-metabolic phenotypes during cross-clamping and to explore their association with early postoperative outcomes.MethodsIn this retrospective single-center study, perfusion data (restricted to the aortic cross-clamp period) were linked with clinical data at the case level. Variables' trajectories were normalized in time, resampled at 15 equidistant points, and represented using DO2i, O2ER, and temperature-adjusted indexed oxygen consumption and carbon dioxide production corrected to 37°C with a Q10-based approach (VO2i_37eq and VCO2i_37eq). Principal component analysis and k-means clustering were applied. Logistic regression was used to assess the association between cluster membership and postoperative acute kidney injury (AKI) according to KDIGO criteria.ResultsSeventy patients were included (mean age 64.3 years, 35.7% females). A 3-cluster solution identified a low-extraction/low-metabolic-demand phenotype, a high-delivery/compensated-metabolic-demand phenotype, and a high-extraction/high-metabolic-stress phenotype. The latter showed the highest incidence of AKI of any stage (53.1%, p = 0.034), the highest incidence of stage 2-3 AKI (18.8%), greater postoperative creatinine increase, and longer intensive care unit stay. In multivariable logistic regression, this phenotype remained associated with postoperative AKI after exploratory multivariable adjustment.ConclusionsTemperature-adjusted unsupervised analysis of perfusion trajectories identified three physiologically coherent phenotypes. The high-extraction/high-metabolic-stress phenotype was associated with the least favorable early postoperative renal profile, supporting a GDP framework beyond DO2i alone.