Targeted Temperature Management in Cardiac Arrest: An Updated Narrative Review

Targeted Temperature Management for Out-of-Hospital Cardiac Arrest Survivors

Targeted temperature management (TTM), specifically therapeutic hypothermia, has been proposed to provide neuroprotective and mortality benefits for out-of-hospital cardiac arrest (OHCA) survivors. This proposition was based on small-scale trials from the early 2000s, leading to its incorporation into various international guidelines. The proposed neuroprotective mechanisms include reducing cerebral metabolic rate, stabilizing the blood-brain barrier, reducing the release of excitatory neurotransmitters, and suppressing apoptotic pathways. However, these early trials have been criticized for their high risk of bias and lack of standardized protocols. Recent evidence from more rigorously controlled randomized trials indicates no significant association between hypothermia and improved neurological outcomes or survival rates. This review explores the latest clinical evidence on TTM for OHCA patients, discussing the pathophysiology, evaluating the effectiveness of hypothermia through various clinical trials, and providing recommendations for future research and clinical practice.

The medical treatment of cardiogenic shock

Cardiogenic shock is characterized by tissue hypoperfusion due to the inadequate cardiac output to maintain the tissue oxygen demand. Despite some advances in cardiogenic shock management, extremely high mortality is still associated with this clinical syndrome. Its management is based on the immediate stabilization of hemodynamic parameters through medical care and the use of mechanical circulatory supports in specialized centers. This review aims to understand the cardiogenic shock current medical treatment, consisting mainly of inotropic drugs, vasopressors and coronary revascularization. In addition, we highlight the relevance of applying measures to other organ levels based on the optimization of mechanical ventilation and the appropriate initiation of renal replacement therapy.

Target Temperature Management Effect on the Clinical Outcome of Patients with Out-of-Hospital Cardiac Arrest Treated with Extracorporeal Cardiopulmonary Resuscitation: A Nationwide Observational Study

This study aimed to investigate whether targeted temperature management (TTM) could enhance outcomes in patients with out-of-hospital cardiac arrest (OHCA) treated with extracorporeal cardiopulmonary resuscitation (ECPR) for refractory cardiac arrest. Using a nationwide OHCA registry, adult patients with witnessed OHCA of presumed cardiac origin who underwent ECPR at the emergency department between 2008 and 2021 were included. We examined the effect of ECPR with TTM on survival and neurological outcomes at hospital discharge using propensity score matching and multivariable logistic regression compared with patients treated with ECPR without TTM. Odds ratios and 95% confidence intervals were determined. A total of 399 ECPR cases were analyzed among 380,239 patients with OHCA. Of these, 330 underwent ECPR without TTM and 69 with TTM. After propensity score matching, 69 matched pairs of patients were included in the analysis. No significant differences in survival and good neurological outcomes between the two groups were observed. In the multivariable logistic regression, no significant differences were observed in survival and neurological outcomes between ECPR with and without TTM. Among the patients who underwent ECPR after OHCA, ECPR with TTM did not improve outcomes compared with ECPR without TTM.

Effectiveness of Induced Hypothermia on the Prognosis of Post-cardiac Arrest Patients: A Scoping Literature Review

Cardiac arrest (CA) is one of the leading causes of death worldwide. Therapeutic hypothermia (TH) is hypothesized to be a reliable practice for better prognosis in post-cardiac arrest (PCA) patients. Medical subject headings (MeSH) terminology was used to search PubMed Central, Medline, and PubMed databases for articles on the use of hypothermia in PCA patients. We selected various clinical trials, meta-analyses and review articles with complete texts in the English language. PCA syndrome occurs after a CA where the body experiences a state of global ischemia and multi-system dysfunction due to the release of reactive oxygen species (ROS) and inflammatory mediators. Hypothermia slows down enzymatic reactions, reduces free radical production, conserves energy, and prevents the accumulation of metabolic waste products. Delaying the time to initiate targeted temperature management (TTM) increases the mortality of patients, the appropriate temperature for TTM has always been debatable. TTM also has various deleterious effects on various organ systems from shivering, and arrhythmias to life-threatening infections but the risks outweigh the benefits for the patients when hypothermia is introduced in PCA care. Our study compares the different modalities to initiate hypothermia from surface cooling devices to intravascular cooling devices, and the adverse effects of each method compared to another.