Control of translation in the cold: implications for therapeutic hypothermia

2015 ◽  
Vol 43 (3) ◽  
pp. 333-337 ◽  
Author(s):  
John R.P. Knight ◽  
Anne E. Willis
Keyword(s):  
Blood Flow ◽  
Therapeutic Hypothermia ◽  
Heart Surgery ◽  
Whole Body ◽  
Potential Importance ◽  
Therapeutic Gain ◽  
Body Cooling ◽  
Whole Body Cooling ◽  
The Brain ◽  
Reduced Temperature

Controlled whole-body cooling has been used since the 1950s to protect the brain from injury where cerebral blood flow is reduced. Therapeutic hypothermia has been used successfully during heart surgery, following cardiac arrest and with varied success in other instances of reduced blood flow to the brain. However, why reduced temperature is beneficial is largely unknown. Here we review the use of therapeutic hypothermia with a view to understanding the underlying biology contributing to the phenomenon. Interestingly, the benefits of cooling have recently been extended to treatment of chronic neurodegenerative diseases in two mouse models. Concurrently studies have demonstrated the importance of the regulation of protein synthesis, translation, to the cooling response, which is also emerging as a targetable process in neurodegeneration. Through these studies the potential importance of the rewarming process following cooling is also beginning to emerge. Altogether, these lines of research present new opportunities to manipulate cooling pathways for therapeutic gain.

Subcutaneous fat necrosis, a rare but serious side effect of hypoxic-ischemic encephalopathy and whole-body hypothermia

2019 ◽  
Vol 47 (9) ◽  
pp. 986-990 ◽  
Author(s):  
Mahdi Alsaleem ◽  
Lina Saadeh ◽  
Valerie Elberson ◽  
Vasantha H.S. Kumar
Keyword(s):  
Therapeutic Hypothermia ◽  
Subcutaneous Fat ◽  
Whole Body ◽  
Subcutaneous Fat Necrosis ◽  
P Values ◽  
Life Threatening ◽  
The Mean ◽  
Body Cooling ◽  
Whole Body Cooling ◽  
Ischemic Encephalopathy

Abstract Objective To describe the clinical characteristics and risk factors in infants with subcutaneous fat necrosis (SFN) following therapeutic hypothermia for hypoxic-ischemic encephalopathy (HIE). Methods A case-control study was performed by a retrospective chart review of infants with moderate or severe HIE admitted to a level IV regional perinatal center and who underwent whole-body cooling. Results A total of 14 (8.1%) of 171 infants with moderate or severe HIE who underwent whole-body cooling developed SFN during hospitalization. There were more females [71% (10/14)] and large-for-gestational age (LGA) infants [28% (4/14)] in the SFN group vs. 36% females (57/157) and 8% LGA infants (13/157) in the group without SFN (P-values of 0.009 and 0.015, respectively). The mean lowest platelet count was lower 108 ± 55 109/L vs. 146 ± 62 109/L and the mean highest calcium level was higher 11.3 ± 2.5 vs. 10.6 ± 0.8 mg/dL in infants with SFN vs. infants without SFN, respectively (P-values of 0.0078 and 0.006, respectively). Distribution of skin lesions followed distinctive patterns representing the areas with direct contact with the cooling blanket. One infant developed severe, life-threatening hypercalcemia that required aggressive management, including diuretics, corticosteroids and bisphosphonates. Conclusion Although SFN is a rare complication of therapeutic hypothermia, it can be a life-threatening condition if complicated by severe hypercalcemia. Infants who undergo therapeutic hypothermia for HIE need regular skin examinations to evaluate for SFN. If SFN is identified, monitoring of serum calcium levels to prevent life-threatening hypercalcemia is recommended.

scholarly journals Selective Thermal Stimulation Delays the Progression of Vasoconstriction During Body Cooling

2019 ◽  
Vol 141 (12) ◽  
Author(s):  
Laura H. Namisnak ◽  
Sepideh Khoshnevis ◽  
Kenneth R. Diller
Keyword(s):  
Blood Flow ◽  
Skin Blood Flow ◽  
Maximum Level ◽  
Thermal Stimulation ◽  
Glabrous Skin ◽  
Whole Body ◽  
Outcome Variable ◽  
Laser Doppler Flow ◽  
Body Cooling ◽  
Whole Body Cooling

Abstract The objective of this study was to test the feasibility of selective thermal stimulation (STS) as a method to upregulate glabrous skin blood flow. STS is accomplished by mild surface heating along the spinal cord. Four healthy subjects were tested in this study. Each participated in a control experiment and an intervention experiment (STS). Both experiments included establishing a maximum level of vasodilation, considered unique to a subject on a test day, and then cooling to a maximum level of vasoconstriction. Perfusion was measured by a laser Doppler flow probe on the index fingertip. The percent of perfusion in the range of minimum to maximum was the primary outcome variable. The data were fit to a linear mixed effects model to determine if STS had a significant influence on perfusion during whole body cooling. STS had a statistically significant effect on perfusion and increased glabrous skin blood flow by 16.3% (P < 0.001, CI (13.1%, 19.5%)) as skin temperature was decreased. This study supports the theory that STS improves the heat exchanger efficiency of palmar and plantar surfaces by increasing the blood flow.

scholarly journals Therapeutic hypothermia in asphyxiated newborns: selective head cooling vs. whole body cooling — comparison of short term outcomes

2019 ◽  
Vol 90 (7) ◽  
pp. 403-410 ◽  
Author(s):  
Ewa Matylda Gulczynska ◽  
Janusz Gadzinowski ◽  
Marcin Kesiak ◽  
Barbara Sobolewska ◽  
Joanna Caputa ◽  
...  
Keyword(s):  
Therapeutic Hypothermia ◽  
Whole Body ◽  
Short Term ◽  
Head Cooling ◽  
Body Cooling ◽  
Whole Body Cooling

scholarly journals Systemic effects of whole-body cooling to 35 °C, 33.5 °C, and 30 °C in a piglet model of perinatal asphyxia: implications for therapeutic hypothermia

2012 ◽  
Vol 71 (5) ◽  
pp. 573-582 ◽  
Author(s):  
Aron Kerenyi ◽  
Dorottya Kelen ◽  
Stuart D. Faulkner ◽  
Alan Bainbridge ◽  
Manigandan Chandrasekaran ◽  
...  
Keyword(s):  
Therapeutic Hypothermia ◽  
Perinatal Asphyxia ◽  
Whole Body ◽  
Systemic Effects ◽  
Body Cooling ◽  
Whole Body Cooling

The role of baseline in the cutaneous vasoconstrictor responses during combined local and whole body cooling in humans

2007 ◽  
Vol 293 (5) ◽  
pp. H3187-H3192 ◽  
Author(s):  
Gary J. Hodges ◽  
Wojciech A. Kosiba ◽  
Kun Zhao ◽  
Guy E. Alvarez ◽  
John M. Johnson
Keyword(s):  
Blood Flow ◽  
Skin Blood Flow ◽  
Local Heating ◽  
Laser Doppler ◽  
Whole Body ◽  
Local Cooling ◽  
Doppler Flowmetry ◽  
Vasoconstrictor Response ◽  
Body Cooling ◽  
Whole Body Cooling

Previous work showed that local cooling (LC) attenuates the vasoconstrictor response to whole body cooling (WBC). We tested the extent to which this attenuation was due to the decreased baseline skin blood flow following LC. In eight subjects, skin blood flow was assessed using laser-Doppler flowmetry (LDF). Cutaneous vascular conductance (CVC) was expressed as LDF divided by blood pressure. Subjects were dressed in water-perfused suits to control WBC. Four forearm sites were prepared with microdialysis fibers, local heating/cooling probe holders, and laser-Doppler probes. Three sites were locally cooled from 34 to 28°C, reducing CVC to 45.9 ± 3.9, 42 ± 3.9, and 44.5 ± 4.8% of baseline ( P < 0.05 vs. baseline; P > 0.05 among sites). At two sites, CVC was restored to precooling baseline levels with sodium nitroprusside (SNP) or isoproterenol (Iso), increasing CVC to 106.4 ± 12.4 and 98.9 ± 10.1% of baseline, respectively ( P > 0.05 vs. precooling). Whole body skin temperature, apart from the area of blood flow measurement, was reduced from 34 to 31°C. Relative to the original baseline, CVC decreased ( P < 0.05) by 44.9 ± 2.8 (control), 11.3 ± 2.4 (LC only), 29 ± 3.7 (SNP), and 45.8 ± 8.7% (Iso). The reductions at LC only and SNP sites were less than at control or Iso sites ( P < 0.05); the responses at those latter sites were not different ( P > 0.05), suggesting that the baseline change in CVC with LC is important in the attenuation of reflex vasoconstrictor responses to WBC.

scholarly journals Effects of face/head and whole body cooling during passive heat stress on human somatosensory processing

2017 ◽  
Vol 312 (6) ◽  
pp. R996-R1003 ◽  
Author(s):  
Hiroki Nakata ◽  
Mari Namba ◽  
Ryusuke Kakigi ◽  
Manabu Shibasaki
Keyword(s):  
Blood Flow ◽  
Heat Stress ◽  
Neural Activity ◽  
Whole Body ◽  
Somatosensory Processing ◽  
Esophageal Temperature ◽  
Passive Heating ◽  
Head Cooling ◽  
Body Cooling ◽  
Whole Body Cooling

We herein investigated the effects of face/head and whole body cooling during passive heat stress on human somatosensory processing recorded by somatosensory-evoked potentials (SEPs) at C4′ and Fz electrodes. Fourteen healthy subjects received a median nerve stimulation at the left wrist. SEPs were recorded at normothermic baseline (Rest), when esophageal temperature had increased by ~1.2°C (heat stress: HS) during passive heating, face/head cooling during passive heating (face/head cooling: FHC), and after HS (whole body cooling: WBC). The latencies and amplitudes of P14, N20, P25, N35, P45, and N60 at C4′ and P14, N18, P22, and N30 at Fz were evaluated. Latency indicated speed of the subcortical and cortical somatosensory processing, while amplitude reflected the strength of neural activity. Blood flow in the internal and common carotid arteries (ICA and CCA, respectively) and psychological comfort were recorded in each session. Increases in esophageal temperature due to HS significantly decreased the amplitude of N60, psychological comfort, and ICA blood flow in the HS session, and also shortened the latencies of SEPs (all, P < 0.05). While esophageal temperature remained elevated, FHC recovered the peak amplitude of N60, psychological comfort, and ICA blood flow toward preheat baseline levels as well as WBC. However, the latencies of SEPs did not recover in the FHC and WBC sessions. These results suggest that impaired neural activity in cortical somatosensory processing during passive HS was recovered by FHC, whereas conduction velocity in the ascending somatosensory input was accelerated by increases in body temperature.

Temperature Distribution in a Realistic Human Head During Selective and Whole Body Cooling and During Circulatory Arrest

2004 ◽  
Author(s):  
Obdulia Ley ◽  
Yildiz Bayazitoglu
Keyword(s):  
Blood Flow ◽  
Temperature Distribution ◽  
Brain Temperature ◽  
Circulatory Arrest ◽  
Temperature Gradients ◽  
Whole Body ◽  
Transient Temperature ◽  
Cooling Strategies ◽  
Body Cooling ◽  
Whole Body Cooling

Using a realistic adult head and neck geometry and a thermal model, the transient temperature distribution is calculated during different cooling strategies and variations in cerebral blood flow. Given the importance of brain temperature in clinical therapy, temperature calculations using thermal models are necessary to optimize hypothermic therapies commonly employed for brain protection during surgery or in the treatment of brain injury. The calculations presented here show the effect of selective and whole body cooling strategies on the temperature gradients in the head; the time required to reach a stationary temperature distribution for the different cooling strategies; the importance of thermal stabilization when using deep hypothermic circulatory arrest, and the effect of selective head cooling in periods of lack of blood flow to control temperature gradients in the brain tissue produced by residual metabolic activity.

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