Temperature Management Methods Research Articles

Continuous monitoring using thermography can capture the heat oscillations maintaining body temperature in neonates

The body temperature of infants at equilibrium with their surroundings is balanced between heat production from metabolism and the transfer of heat to the environment. Total heat production is related to body size, which is closely related to metabolic rate and oxygen consumption. Body temperature control is a crucial aspect of neonatal medicine but we have often struggled with temperature measures. Contactless infrared thermography (IRT) is useful for vulnerable neonates and may be able to assess their spontaneous thermal metabolism. The present study focused on heat oscillations and their cause. IRT was used to measure the skin temperature every 15 s of neonates in an incubator. We analyzed the thermal data of 27 neonates (32 measurements), calculated the average temperature within specified regions, and extracted two frequency components—Components A and B—using the Savitzky–Golay method. Furthermore, we derived an equation describing the cycle—named cycle T—for maintaining body temperature according to body weight. A positive correlation was observed between cycle T and Component B (median [IQR]: 368 [300–506] s). This study sheds light on the physiological thermoregulatory function of newborns and will lead to improved temperature management methods for newborns, particularly premature, low-birth-weight infants.

Review of Temperature Management in Traumatic Brain Injuries.

Therapeutic hypothermia (TH) for severe traumatic brain injury has seen restricted application due to the outcomes of randomized controlled trials (RCTs) conducted since 2000. In contrast with earlier RCTs, recent trials have implemented active normothermia management in control groups, ensuring comparable intensities of non-temperature-related therapeutic interventions, such as neurointensive care. This change in approach may be a contributing factor to the inability to establish the efficacy of TH. Currently, an active temperature management method using temperature control devices is termed "targeted temperature management (TTM)". One of the goals of TTM for severe traumatic brain injury is the regulation of increased intracranial pressure, employing TTM as a methodology for intracranial pressure management. Additionally, fever in traumatic brain injury has been acknowledged as contributing to poor prognosis, underscoring the importance of proactively preventing fever. TTM is also employed for the preemptive prevention of fever in severe traumatic brain injury. As an integral component of current neurointensive care, it is crucial to precisely delineate the targets of TTM and to potentially apply them in the treatment of severe traumatic brain injury.

Recovery and Survival of Patients After Out-of-Hospital Cardiac Arrest: A Literature Review Showcasing the Big Picture of Intensive Care Unit-Related Factors.

As an important public health issue, out-of-hospital cardiac arrest (OHCA) requires several stages of high quality medical care, both on-field and after hospital admission. Post-cardiac arrest shock can lead to severe neurological injury, resulting in poor recovery outcome and increasedrisk of death. These characteristics make this conditionone of the most important issues to deal with in post-OHCA patients hospitalized in intensive care units (ICUs). Also, the majority of initial post-resuscitation survivors haveunderlying coronary diseases makingrevascularization procedure another crucial step in early management of these patients. Besides keeping myocardial blood flow at a satisfactory level, other tissues must not be neglected as well, and maintaining mean arterial pressure within optimal range is also preferable. All these procedures can be simplified to a certain level along with using targeted temperature management methods in order to decrease metabolic demands in ICU-hospitalized post-OHCA patients. Additionally, withdrawal of life-sustaining therapy as a controversial ethical topic is under constant re-evaluation due to its possible influence on overall mortality rates in patients initially surviving OHCA. Focusing on all of these important points in process of managing ICU patients is an imperative towards better survival and complete recovery rates.

Differences in Flow Rate Accuracy in Natural Instillation Using Different Infusion Temperature Management Methods: A Pilot Study

Differences in Flow Rate Accuracy in Natural Instillation Using Different Infusion Temperature Management Methods: A Pilot Study

Cost-Effectiveness Analysis of Intravascular Targeted Temperature Management after Cardiac Arrest in England.

BackgroundTargeted temperature management (TTM) has been shown to improve neurological outcomes and survival in patients resuscitated from cardiac arrest; however, the cost effectiveness of multiple TTM methods is not well studied.ObjectiveThis study aimed to evaluate the cost effectiveness of intravascular temperature management (IVTM) using Thermogard XP compared with surface cooling methods after cardiac arrest in the England from the perspectives of the UK national health service and Personal Social Services.MethodsWe developed a multi-state Markov model that evaluated IVTM (Thermogard XP) compared with surface cooling using two different devices (Blanketrol III and Arctic Sun 5000) over a short-term and lifetime time horizon. Model input parameters were obtained from the literature and local databases. We assumed a hypothetical cohort of 1000 patients who required TTM after cardiac arrest per year in the England. The outcomes were costs (in £, year 2019 values) and quality-adjusted life-years (QALYs), discounted at 3.5% annually. Deterministic and probabilistic sensitivity analyses were undertaken to examine the effect of alternative assumptions and uncertainty in model parameters on the results.ResultsThe cost-effectiveness analysis determined that Thermogard XP resulted in direct cost savings of £2339 and £2925 (per patient) compared with Blanketrol III and Arctic Sun 5000, respectively, and a gain of 0.98 QALYs over the patient lifetime. The probabilistic sensitivity analysis demonstrated that the probability of Thermogard XP being cost saving would be 69.2% and 65.3% versus the Arctic Sun 5000 and Blanketrol III, respectively.ConclusionImplementation of IVTM using Thermogard XP can lead to cost savings and improved patient quality of life versus surface cooling methods.Supplementary InformationThe online version contains supplementary material available at 10.1007/s41669-022-00333-7.

Details of Targeted Temperature Management Methods for Patients Who Had Out-of-Hospital Cardiac Arrest Receiving Extracorporeal Cardiopulmonary Resuscitation: A Questionnaire Survey.

This study aimed to precisely describe the details of targeted temperature management (TTM) following extracorporeal cardiopulmonary resuscitation (ECPR) in patients with out-of-hospital cardiac arrest (OHCA). A questionnaire to examine the TTM details following ECPR was distributed to 36 medical institutions that participated in the Study of Advanced life support for Ventricular fibrillation with Extracorporeal circulation in Japan (SAVE-J) II study. The survey was conducted using an anonymous questionnaire through the Internet and was distributed in January 2021 and collected in February 2021. Practical TTM methods (induction, maintenance, and rewarming duration) and monitoring and management methods, such as target levels, drugs, left ventricular decompression therapy, nutrition, and rehabilitation therapy, were recorded. We received responses from all 36 institutions. The target temperature was initiated at 34°C in 72.2% of institutions. In ∼90% of institutions, the maintenance duration was 24 hours, which was also the leading duration of rewarming 24 hours (38.9%), followed by 48 hours (30.6%). Electroencephalogram is routinely applied in only 13.9% of institutions. Prophylactic antibiotics were used in 58.6% of institutions. Enteral nutrition during TTM is consistently initiated in 27.8% of institutions and 33.3% of institutions initiated enteral nutrition for patients without catecholamine requirements. The 24-48 hours (55.6%) was the leading period of initiating early rehabilitation, followed by <24 hours. This survey described the details of the current practice for treating patients with OHCA by TTM following ECPR. Since various factors were undetermined in the TTM, randomized controlled trials will be necessary to resolve issues during TTM following ECPR.

Investigation of the growth and removal of particles in coal-fired flue gas by temperature management

Flue gas generated from coal combustion is the primary source of air pollution. Temperature is an essential parameter for the treatment process of flue gas pollutants. In this study, a field-scale demonstration setup was used to investigate the effect of temperature on particle growth and removal by using actual flue gas. The ionic migration in heat exchanger was also studied, and a temperature management method was established. Results showed that the temperature had a substantial influence on particle growth and removal, the outlet particle median diameter increased from 0.116 µm to 0.155 µm, and the outlet particle mass concentration decreased from 7.05 mg/Nm3 to 4.49 mg/Nm3 when the flue gas temperature difference was 2.9–4.6 K. Changing the boiler load from 100% to 65% led to the increase in the particle removal efficiency from 78.06% to 80.33%. This increment was mainly related to the changes in temperature. In addition, when the temperature difference increased from 2.9 K to 4.6 K, the concentration of the ions in the sample significantly increased, and the removal amount of mercury was enhanced by 2.57 times. The pollutant in the flue gas was effectively removed by the temperature management installation between the wet flue gas desulfurization and wet electrostatic precipitator.

Temperature Management Methods for Selective Brain Hypothermia in Variable Metabolism

Brain hypothermia is widely operated to prevent peripheral healthy brain tissue from secondary damage, caused by increased brain temperature due to hypermetabolism around the damaged areas. Selective brain hypothermia is a new clinical technique of brain hypothermia for a brain disorder. Appropriate solution in a controlled temperature is directly infused into the artery to cool down a brain tissue through some catheters. While the brain temperature is controlled quickly, the body temperature has to be kept within a prescribed range by re‐warmed cerebrovascular blood return to the systemic circulation. As metabolic changes in the brain is variable due to the complex behavior of the disease state with the treatment effect. . In the present study two adaptive control methods as adaptive‐gain control and Fuzzy‐adaptive control are provided to carry out for precise temperature control for selective brain hypothermia. Several kinds of mathematical brain models with cerebrovascular damage are specially used to evaluate our temperature control methods. The effectiveness of the management of the brain temperature is demonstrated for four kinds control laws and five mathematical clinical brain models. © 2021 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.

Targeted temperature management in patients with intracerebral haemorrhage, subarachnoid haemorrhage, or acute ischaemic stroke: consensus recommendations

BackgroundA modified Delphi approach was used to identify a consensus on practical recommendations for the use of non-pharmacological targeted temperature management in patients with intracerebral haemorrhage, subarachnoid haemorrhage, or acute ischaemic stroke with non-infectious fever (assumed neurogenic fever). MethodsNine experts in the management of neurogenic fever participated in the process, involving the completion of online questionnaires, face-to-face discussions, and summary reviews, to consolidate a consensus on targeted temperature management. ResultsThe panel's recommendations are based on a balance of existing evidence and practical considerations. With this in mind, they highlight the importance of managing neurogenic fever using a single protocol for targeted temperature management. Targeted temperature management should be initiated if the patient temperature increases above 37.5°C, once an appropriate workup for infection has been undertaken. This helps prevent prophylactic targeted temperature management use and ensures infection is addressed appropriately. When neurogenic fever is detected, targeted temperature management should be initiated rapidly if antipyretic agents fail to control the temperature within 1 h, and should then be maintained for as long as there is potential for secondary brain damage. The recommended target temperature for targeted temperature management is 36.5–37.5°C. The use of advanced targeted temperature management methods that enable continuous, or near continuous, temperature measurement and precise temperature control is recommended. ConclusionsGiven the limited heterogeneous evidence currently available on targeted temperature management use in patients with neurogenic fever and intracerebral haemorrhage, subarachnoid haemorrhage, or acute ischaemic stroke, a Delphi approach was appropriate to gather an expert consensus. To aid in the development of future investigations, the panel provides recommendations for data gathering.

Randomized controlled trial of internal and external targeted temperature management methods in post- cardiac arrest patients

BackgroundTargeted temperature management post-cardiac arrest is currently implemented using various methods, broadly categorized as internal and external. This study aimed to evaluate survival-to-hospital discharge and neurological outcomes (Glasgow-Pittsburgh Score) of post-cardiac arrest patients undergoing internal cooling verses external cooling. MethodologyA randomized controlled trial of post-resuscitation cardiac arrest patients was conducted from October 2008–September 2014. Patients were randomized to either internal or external cooling methods. Historical controls were selected matched by age and gender. Analysis using SPSS version 21.0 presented descriptive statistics and frequencies while univariate logistic regression was done using R 3.1.3. Results23 patients were randomized to internal cooling and 22 patients to external cooling and 42 matched controls were selected. No significant difference was seen between internal and external cooling in terms of survival, neurological outcomes and complications. However in the internal cooling arm, there was lower risk of developing overcooling (p=0.01) and rebound hyperthermia (p=0.02). Compared to normothermia, internal cooling had higher survival (OR=3.36, 95% CI=(1.130, 10.412), and lower risk of developing cardiac arrhythmias (OR=0.18, 95% CI=(0.04, 0.63)). Subgroup analysis showed those with cardiac cause of arrest (OR=4.29, 95% CI=(1.26, 15.80)) and sustained ROSC (OR=5.50, 95% CI=(1.64, 20.39)) had better survival with internal cooling compared to normothermia. Cooling curves showed tighter temperature control for internal compared to external cooling. ConclusionInternal cooling showed tighter temperature control compared to external cooling. Internal cooling can potentially provide better survival-to-hospital discharge outcomes and reduce cardiac arrhythmia complications in carefully selected patients as compared to normothermia.

Thermal management in 3d networks-on-chip using dynamic link sharing

3D integration is a practical solution for overcoming the problems of long and slow global wires in current and future generations of integrated circuits. This emerging technology stacks several die slices on top of each other in a single chip. It provides higher-bandwidth and lower-latency in the third dimension than a 2D design due to extremely shorter inter-layer distances. However, thermal challenges are a key impediment to stacking logic dies on top of each other. Particularly, routers in a 3D network-on-chip (NoC) are a main source of thermal hotspots, limiting the potential performance gains of the 3D integration. In this paper, we take advantage of the low-latency 3D vertical links to design a temperature-aware router architecture for 3D NoCs. This architecture reduces the peak temperature of routers, particularly routers that are farther from the heat sink, by balancing the traffic across all layers in a temperature-aware distributed way. This way, a router with high temperature can borrow the link and crossbar bandwidth of the routers in the layers closer to the heat sink to forward its packets, effectively offloading part of its traffic to them to reduce its temperature.Experimental results show that the proposed method can control the temperature of 3D NoCs and reduce the temperature gradient across the network with minimized negative impact on performance, compared to a state-of-the-art 3D NoC temperature management method.

Effectiveness of different targeted temperature management methods for fever in patients with acute cerebral infarction

Objectives: To observe the effectiveness of different targeted temperature management (TTM) methods in patients with acute cerebral infarction (ACI) and explore the most feasible cooling strategies for ACI. Methods: We retrospectively analyzed the effectiveness of different TTM strategies for ACI patients treated in the Neuointensive Care Unit of South Hospital of Southern Medical University from June 1, 2012 to May 31, 2015. Patients were divided into four groups according to the presence or absence of fever and the cooling method: control group (n=63, normal body temperature), group A (ibuprofen alone, n=53), group B (ice bag alone, n=49), and group AB (ibuprofen + ice bag, n=62). We measured rectal temperature at admission and 1 h, 2 h, 4 h, 6 h, 12 h, 48 h and 72 h after admission in the control group. In groups A, B, and AB, we measured rectal temperature immediately after cooling and 1 h, 2 h, 4 h, 6 h, 12 h, 48 h, and 72 h after cooling. Results: Body temperature showed no significant difference immediately after cooling among groups A, B, and AB (P>0.05); however, cooling effectiveness was significantly different at multiple time points after cooling (P<0.05). Body temperature decrease was greater in group A, in which cooling effectiveness was more obvious. During cooling, body temperature in group B was slightly lower than that in group A, but the difference was not statistically significant. After cooling, body temperature decrease was significantly greater in group A than in groups B and AB (P<0.05). Conclusion: For ACI patients, ibuprofen alone is superior to ice-bag cooling or ibuprofen + ice bag cooling.

Cerebral Effects of Targeted Temperature Management Methods Assessed by Diffusion-Weighted Magnetic Resonance Imaging

The aim of this randomized porcine study was to compare surface targeted temperature management (TTM) to endovascular TTM evaluated by cerebral diffusion-weighted magnetic resonance imaging (MRI): apparent diffusion coefficient (ADC), and by intracerebral/intramuscular microdialysis. It is well known that alteration in the temperature affects ADC, but the relationship between cerebral ADC values and the cooling method per se has not been established. Eighteen anesthetized 60-kg female swine were hemodynamically and intracerebrally monitored and subsequently subjected to a baseline MRI. The animals were then randomized into three groups: (1) surface cooling (n = 6) at 33.5°C using EMCOOLSpad®, (2) endovascular cooling (n = 6) at 33.5°C using an Icy® cooling catheter with the CoolGard 3000®, or (3) control (n = 6) at 38.5°C using a Bair Hugger™. The swine were treated with TTM for 6 hours followed by a second MRI examination, including ADC. Blood and microdialysate were sampled regularly throughout the experiment, and glucose, lactate, pyruvate, glycerol, and the lactate/pyruvate ratio did not differ among groups, neither intracerebrally nor intramuscularly. Surface cooling yielded a significantly lower median ADC than endovascular cooling: 714 (634; 804) × 10-6 mm2/s versus 866 (828; 927) × 10-6 mm2/s, (p < 0.05). The surface cooling ADC was lowered to a range usually attributed to cytotoxic edema and these low values could not be explained solely by the temperature effect per se. To what extent the ADC is fully reversible at rewarming is unknown and the clinical implications should be further investigated in clinical studies.

비닐하우스 이용 고추 건조시 야간 온도 관리 방법이 태양초 품질에 미치는 영향

비닐하우스 이용 고추 건조시 야간 온도 관리 방법이 태양초 품질에 미치는 영향

Seven recipes for setting your FPGA on fire – A cookbook on heat generators

Due to the continuously shrinking device structures and increasing densities of FPGAs, thermal aspects have become the new focus for many research projects over the last years. Most researchers rely on temperature simulations to evaluate their novel thermal management techniques. However, these temperature simulations require a high computational effort if a detailed thermal model is used and their accuracies are often unclear.In contrast to simulations, the use of synthetic heat sources allows for experimental evaluation of temperature management methods. In this paper we investigate the creation of significant rises in temperature on modern FPGAs to enable future evaluation of thermal management techniques based on experiments. To that end, we have developed seven different heat-generating cores that use different subsets of FPGA resources. Our experimental results show that, according to external temperature probes connected to the FPGA’s heat sink, we can increase the temperature by an average of 81°C. This corresponds to an average increase of 156.3°C as measured by the built-in thermal diodes of our Virtex-5 FPGAs in less than 30min by only utilizing about 21 percent of the slices.

Multi-scale modeling on human intravascular cooling to induce brain hypothermia via circle of Willis

Therapeutic hypothermia has been the most effective therapy to treat serious cardiovascular and cerebrovascular diseases. Among them, intravascular cooling is identified as a most efficient approach to induce brain hypothermia. However until now, some key parameters and temperature management method for intravascular cooling are still not well addressed because of the complexity of human thermoregulation mechanism. Aiming at predicting temperature variation of tissues and organs in a more accurate way during therapeutic hypothermia, this study is dedicated to integrate the blood flow model in the circle of Willis together with the compartmental model for characterizing the heat and blood transport throughout the whole human body. According to the theoretical evaluation, the new model could well simulate the temperature response of the whole human body especially the brain under various cooling. Effects of different intervention site and cooling power to the hypothermia performance are discussed, which shows that carotid artery intervention is a more suitable therapeutic hypothermia method in comparison with femoral artery or femoral vein intervention. These results could help design controlling software for intravascular therapeutic hypothermia device in the near future.

Evaluation of a new temperature management system during off-pump coronary artery bypass

We evaluated the performance of a new temperature management system (Arctic Sun, Medivance, Inc.) in maintaining normothermia during off-pump coronary artery bypass (OPCAB). Ninety-eight unselected patients were prospectively randomized to either a conventional temperature management method (consisting of a sterile forced-air warming blanket, warm intravenous fluids, and maintenance of a warm OR) or the new Arctic Sun system (two pads, Arctic Sun Energy Transfer Pads placed on the patient's back with temperature-controlled water flowing through the pads). The mean age, body surface area, and total operating time were similar in both groups. Despite significantly lower room temperatures (p<0.001) in the Arctic Sun group, the system maintained higher bladder and nasopharyngeal temperatures (p<0.001 and p<0.001, respectively). A core temperature of at least 36 degrees C was achieved in 97% of the Arctic Sun patients compared with 42% in the conventional group. Additionally, intra-operative blood loss for the Arctic Sun patients was significantly less (p=0.01). The Arctic Sun system significantly outperformed conventional techniques in achieving and maintaining normothermia during off-pump coronary artery bypass.