Whole-Body Cooling Research Articles

Upper- vs. Whole-Body Cooling During Exercise with Thermal Protective Clothing in the Heat.

INTRODUCTION: Firefighters operating in hot environments face challenges from protective garments that restrict heat dissipation, resulting in increased core temperature, thermal discomfort, and performance decline. Cooling vests represent a viable solution. The study aim was to compare effectiveness of the same amount of cooling power to the upper body (UB) or whole body (WB) in alleviating thermoregulatory and physiological stress, enhancing cognitive function, and reducing ratings of thermal discomfort and exertion, during 60 min of exercise in a hot environment (40°C, 40% relative humidity) while wearing firefighter turnout gear.METHODS: Eight healthy individuals (27.5 ± 3 y) participated in three conditions with either no cooling (Control) or active cooling with a liquid perfused shirt (UB cooling), or with a liquid perfused shirt and pants (WB cooling). In each trial, subjects performed three sets of 15 min of stepping (20 steps ⋅ min-1) and 5 min of rest.RESULTS: Both cooling strategies were beneficial compared to having no cooling at all. Subjects could only complete two exercise bouts during Control, but they completed all three bouts with active cooling. WB cooling provided an advantage over UB cooling for core and skin temperature, and thermal comfort and sensation. The advantage in minimizing the increase in core temperature was only evident during the third exercise bout.DISCUSSION: Active cooling is advantageous under these conditions. WB cooling provided some benefits vs UB cooling during heavy intensity exercise; however, it is uncertain whether these benefits would be observed during light-to-moderate exercise, which more likely reflects an actual firefighting scenario.Mansouri F, Talebian Nia M, Villar R, Cornish SM, Giesbrecht GG. Upper- vs. whole-body cooling during exercise with thermal protective clothing in the heat. Aerosp Med Hum Perform. 2024; 95(9):659-666.

Subcutaneous Fat Necrosis of the Newborn After Whole-Body Cooling for Birth Asphyxia

Therapeutic hypothermia (TH) is a challenging treatment for a neonate who suffers from hypoxic-ischemic encephalopathy. It has been shown to improve neurodevelopmental outcomes and survival ininfants with moderate-to-severe hypoxic-ischemic encephalopathy.However, it has severe adverse effects such as subcutaneous fat necrosis (SCFN). SCFN is a rare disorder that affects term neonates. It is a self-limited disorder but can have severe complications such as hypercalcemia, hypoglycemia, metastatic calcifications, and thrombocytopenia. In this case report, we present a term newborn who developed SCFN after whole-body cooling.

Is Selective Head Cooling Combined with Whole-Body Cooling the Most Effective Hypothermia Method for Neonatal Hypoxic-Ischemic Encephalopathy?

This study aimed to compare combined hypothermia (CH) to the 2 classical therapeutic hypothermia (TH) methods selective head cooling (SHC) and whole-body cooling (WBC). This retrospective cohort study included neonates who underwent CH, SHC, and WBC between 2012 and 2020. Mean rectal temperature was maintained at 33.5 ± 0.5°C by cooling the head and the body in the CH group, at 34.5 ± 0.5°C by cooling the head in the SHC group, and at 33.5 ± 0.5°C by cooling the body in the WBC group. The groups were compared in terms of side effects, magnetic resonance imaging (MRI) scores, and status at discharge. The study included 60 neonates in the CH group, 112 in the WBC group, and 27 in the SHC group. There was no significant difference in side effects between the groups (p > 0.05). There was no significant difference in brain MRI scores between the groups (p > 0.05); however, gray matter, white matter, and total MRI scores in the CH group were lower than in the WBC group. Duration of hospitalization was shorter in the CH group than in the other two groups (p = 0.022). CH was not associated with more side effects than the two classical TH methods. In addition, some of these findings suggest that CH might result in better clinical outcome than the two classical TH methods.

Recording of Complications of Treatment of Hypoxic Ischemic Neonates by Passive Whole-Body Cooling: A Study in Neonatal Intensive Care Unit of Mataria Teaching Hospital

Recording of Complications of Treatment of Hypoxic Ischemic Neonates by Passive Whole-Body Cooling: A Study in Neonatal Intensive Care Unit of Mataria Teaching Hospital

Selective head cooling or whole body cooling? That is the question

Background. Studies to date support the beneficial effect that therapeutic hypothermia (TH) has on neonates with hypoxic-ischemic encephalopathy. TH can be delivered in two ways: selective head cooling (SHC) or therapeutic whole-body cooling (WBC). The purpose of this review is to examine the literature to expose the advantages and disadvantages of the two methods of performing TH in neonates diagnosed with moderate or severe HIE and to investigate whether one method is superior to the other. Methods. We started from the data from the Cochrane review published in 2013 [1] and we want to bring new information from recent clinical studies comparing the two TH methods (SHC vs WBC). Clinical studies were searched and analyzed by a single individual (through dedicated search engines such as Google Scholar, PubMed, and Scopus). We have included clinical studies from the last 7 years comparing the two ways of performing TH (SHC vs. WBC). We selected only the articles that compared the two methods and excluded the articles describing only one method. Results. After excluding the clinical trials that did not meet the eligibility criteria, 5 clinical trials remained (n = 256 neonates). Analysis of these studies supports the idea that both modalities of therapeutic hypothermia cool central nervous system (CNS) structures and have a similar neurodevelopmental prognosis among surviving neonates. Also, there are no significant differences in terms of short-term neurological prognosis, as well as the adverse effects that may occur in neonates with moderate or severe HIE (hypoxic-ischemic encephalopathy) treated with SHC or WBC; although some studies note the presence of more severe, statistically significant lesions among patients treated with SHC compared to those treated with WBC. Conclusions. Prospective, randomized studies on a much larger scale are needed to track the adverse effects that the two HT methods may have on patients, as well as long-term neurological and cognitive prognosis. Until now, there is no clear evidence that one of these two methods is definitely safer or more reliable than the other.

Risk Factors for Clinical Seizures in Neonates with Hypoxic-ischemic Encephalopathy Treated with Therapeutic Hypothermia.

This study aimed to assess the risk factors for clinical seizures in newborns treated with whole body cooling (WBC) for hypoxic ischemic encephalopathy (HIE). Infants with gestational age≥36 weeks and birth weight≥2.000 g who were treated with WBC due to HIE were retrospectively enrolled in this study. Patients were assigned to two groups: infants without clinical seizures (Group 1) and infants with clinical seizures (Group 2). The two groups were compared to determine the risk factors for the occurrence of clinical seizures. A total of 25 patients (Group 1=10 and Group 2=15) were included in the study. Prothrombin time (PT) was determined as independent risk factor for clinical seizures (p=0.046) and the odds ratio for the effect of PT was found as 1.475 (%95 CI:1.006-2.299). PT (area under the curve [AUC]=0.764; p=0.041), and increased cardiac troponin-I (cTnI) (AUC=0.935; p=0.002) were found to be significant risk factors for predicting the occurrence of clinical seizures. The optimal PT cut-off value was 22.7 sec, with a sensitivity and specificity of 45.4% and 90%, respectively; as well as positive and negative predictive value of 83.3% and 60.0%, respectively. The chest compression in the delivery room, severely abnormal amplitude integrated electroencephalography and high encephalopathy score were also found risk factors for occurrence of clinical seizures. Chest compression in the delivery room, high encephalopathy score, prolonged PT, and increased cTnI are significant factors for clinical seizures in newborns treated with WBC for HIE.

Exogenous Ketone Salt Supplementation and Whole-Body Cooling Do Not Improve Short-Term Physical Performance.

Exogenous ketone supplementation and whole-body cooling (WBC) have shown to independently influence exercise metabolism. Whether readily available ketone salts, with and without WBC, would provide similar metabolic benefits during steady-state aerobic and time-trial performances was investigated. Nine active males (VO2peak: 56.3 ± 2.2 mL·kg−1·min−1) completed three single-blind exercise sessions preceded by: (1) ingestion of placebo (CON), (2) ketone supplementation (0.3 g·kg−1 β-OHB) (KET), and (3) ketone supplementation with WBC (KETCO). Participants cycled in steady-state (SS, 60% Wmax) condition for 30-min, immediately followed by a 15-min time trial (TT). Skin and core temperature, cardio-metabolic, and respiratory measures were collected continuously, whereas venous blood samples were collected before and after supplementation, after SS and TT. Venous β-OHB was elevated, while blood glucose was lower, with supplementation vs. CON (p < 0.05). TT power output was not different between conditions (p = 0.112, CON: 190 ± 43.5 W, KET: 185 ± 40.4 W, KETCO: 211 ± 50.7 W). RER was higher during KETCO (0.97 ± 0.09) compared to both CON (0.88 ± 0.04, p = 0.012) and KET (0.88 ± 0.05, p = 0.014). Ketone salt supplementation and WBC prior to short-term exercise sufficiently increase blood β-OHB concentrations, but do not benefit metabolic shifts in fuel utilization or improve time trial performance.

Outcome of Infants with Hypoxic-Ischemic Encephalopathy Treated by Whole Body Cooling and Magnesium Sulfate

AbstractTherapeutic hypothermia (TH) either by selective head cooling or whole-body cooling decreases brain damage and provide neuroprotection and reduced mortality rate in cases of moderate-to-severe hypoxia-ischemia encephalopathy (HIE) of newborns, especially if started at first 6 hours after birth. Also, management with adjuvant therapies like magnesium sulfate (MS) provides more neuroprotection. The interventional randomized controlled research aimed to assess short-term actions of TH as sole therapy and in combination with MS as a neuroprotective agent for the treatment of HIE newborn infants. A total of 36 full-terms and near-term infants delivered at Assiut University Children's Hospital and fulfilled HIE criteria were enrolled. They were divided equally into three groups; Group 1 (n = 12) received whole body cooling during first 6 hours of life as a sole therapy; Group 2 (n = 12) received whole body cooling in addition to MS as adjuvant therapy; Group 3 (n = 12) received supportive intensive care measures as a control. TH plus MS group (group 2) had a significantly good short-term outcomes as short period of respiratory support and mechanical ventilation (p-value =0.001), less in incidence of convulsion (p-value = 0.001) and early in feeding initiation (p-value = 0.009), compared with other groups managed by TH (group 1) or by supportive treatment (group 3). In conclusion, whole body cooling in addition to MS as adjunctive therapy for the treatment of HIE neonates is safe therapy that improves short-term outcome both clinically and radiologically.

Directional Interactions Between Constituents of the Human Large-Scale Thermoregulatory Network

In humans, dynamic thermoregulation is (presumably) underpinned by a complex hierarchy of functional interactions between constituents of the human thermoregulatory large-scale network. However, these interactions have not been quantified from in vivo fMRI signals acquired during the experimental delivery of whole-body thermal stress. Here, we used directed functional connectivity (dFC) analysis (based on multi-variate autoregressive models) to recover directed interactions within a single thermoregulatory network during an experimental paradigm that involved controlled exposure to whole-body cooling and warming. MRI studies were performed in 30 young adults (15M/15F, mean age 25.1 ± 3.4years). Gradient echo EPI fMRI data were acquired on a 3T Siemens Verio system. The thermoregulatory challenge was applied using a specialized whole-body garment covering the entire body. Tubes lining the innards of the suit were infused with cold (2-4°C) or neutral (31-34°C) water to induce whole-body Cooling or Warming while fMRI data were contemporaneously acquired. dFC was estimated within and between the hierarchically organized homeostatic (midbrain, pons), interoceptive (insula) and executive (anterior cingulate, orbitofrontal and superior parietal cortices) sub-networks using multi-variate autoregressive models applied to the fMRI time series data. Estimates of directed interactions (akin to Granger Causality) between nodes were analyzed to recover ascending (homeostatic sub-network "upward"), descending (executive sub-network "downward"), and lateral (within sub-network) directional ("causal") effects. Both Cooling and Warming induced complex hierarchical interactions in the thermoregulatory large-scale network. Cooling induced ascending interactions from the homeostatic (midbrain) to both the executive (OFC) and interoceptive (insula) sub-networks, particularly to the superior parietal, ACC and the anterior and posterior insulae. In comparison, descending interactions were induced from the posterior insula. Warming induced ascending interactions from the homeostatic sub-network to notably the OFC (executive) and the insulae (interoceptive). Descending interactions were induced from the ACC and the OFC. Sparser effects appear from the executive to the interoceptive sub-network during warming. Our study demonstrates a hierarchical organization of thermoregulatory function between homeostatic, interoceptive and executive sub-networks. The observed information flow between/within these is consistent with a reentrant property of the hierarchical regulatory structure, characterized by the ongoing bi-directional exchange of signals along reciprocal axonal fibers linking the various nodes.

An In Vivo Assessment of Regional Brain Temperature during Whole-Body Cooling for Neonatal Encephalopathy

To assess differences in regional brain temperatures during whole-body hypothermia and test the hypothesis that brain temperature profile is nonhomogenous in infants with hypoxic-ischemic encephalopathy. Infants with hypoxic-ischemic encephalopathy were enrolled prospectively in this observational study. Magnetic resonance (MR) spectra of basal ganglia, thalamus, cortical gray matter, and white matter (WM) were acquired during therapeutic hypothermia. Regional brain tissue temperatures were calculated from the chemical shift difference between water signal and metabolites in the MR spectra after performing calibration measurements. Overall difference in regional temperature was analyzed by mixed-effects model; temperature among different patterns and severity of injury on MR imaging also was analyzed. Correlation between temperature and depth of brain structure was analyzed using repeated-measures correlation. In total, 53 infants were enrolled (31 girls, mean gestational age: 38.6±2weeks; mean birth weight: 3243±613g). MR spectroscopy was acquired at mean age of 2.2±0.6days. A total of 201MR spectra were included in the analysis. The thalamus, the deepest structure (36.4±2.3mm from skull surface), was lowest in temperature (33.2±0.8°C, compared with basal ganglia: 33.5±0.9°C; gray matter: 33.6±0.7°C; WM: 33.8±0.9°C, all P < .001). Temperatures in more superficial gray matter and WM regions (depth: 21.9±2.4 and 21.5±2.2mm) were greater than the rectal temperatures (33.4±0.4°C, P < .03). There was a negative correlation between temperature and depth of brain structure (rrm=-0.36, P < .001). Whole-body hypothermia was effective in cooling deep brain structures, whereas superficial structures were warmer, with temperatures significantly greater than rectal temperatures.

Взаимосвязь эритроцитарных, тромбоцитарных показателей и гематокрита в крови с характером иммунной реакции человека на кратковременное общее охлаждение

Взаимосвязь эритроцитарных, тромбоцитарных показателей и гематокрита в крови с характером иммунной реакции человека на кратковременное общее охлаждение

Effect of erythropoietin as adjunctive therapy with whole-body cooling for treatment of hypoxic-ischemic encephalopathy in newborns

Background Hypothermia induced by whole-body cooling (WBC) and/or selective head cooling reduces brain injury after hypoxia-ischemia in newborns. Despite differences in approach (head cooling vs. total body cooling), there is a general agreement that hypothermia improves outcomes of moderately asphyxiated infants, decreasing the combined outcome of death and neurologic dysfunction from 60 to 45%. Subsequently, the search for adjuvant therapies that may provide long-lasting neuroprotection was mandatory. Aim of the present work The present study aimed to evaluate the short-term effects of erythropoietin (Epo) as a neuroprotective agent in adjunction with WBC to treat newborn infants with hypoxic-ischemic encephalopathy (HIE). Participants and methods This is a true interventional randomized controlled hospital-based study. A total of 33 full-term and late preterm newborn infants, delivered at El-Shatby Alexandria University Maternity Hospital, Egypt, were enrolled in the study. They fulfilled the criteria of HIE and received WBC during the first 6 h of life, in addition to the standard intensive care measures. Of the 33 studied babies, 11 received 500 IU/kg Epo every other day for 2 weeks as adjunctive therapy to WBC. Results The Epo plus WBC group (group I) had a significantly shorter period of hospital stay in comparison with the other group managed by WBC solely (group II), [mean hospital stay in days±SD: 6.20±2.39 and 8.40±3.94, respectively (P=0.039)]. The incidence of seizures was insignificantly lower among babies in group I. Extensive white and gray matter brain lesions were observed more among group II neonates, although the difference was statistically insignificant. Clinical and neurological improvements, as guided by Thomson score, were better achieved among group I babies, despite the difference being statistically insignificant. Conclusion Epo as an adjunctive therapy with WBC for treating asphyxiated neonates is a safe mode of therapy, which significantly shortens the period of hospital stay as well as it (marginally) improves their short-term outcome, both radiologically and clinically. WBC plus Epo lowers the rate of occurrence of clinically detectable seizures in the 1st week of life among asphyxiated neonates.

Tarp-Assisted Cooling as a Method of Whole-Body Cooling in Hyperthermic Individuals

We investigated the efficacy of tarp-assisted cooling as a body cooling modality. Participants exercised on a motorized treadmill in hot conditions (ambient temperature 39.5°C [103.1°F], SD 3.1°C [5.58°F]; relative humidity 38.1% [SD 6.7%]) until they reached exercise-induced hyperthermia. After exercise, participants were cooled with either partial immersion using a tarp-assisted cooling method (water temperature 9.20°C [48.56°F], SD 2.81°C [5.06°F]) or passive cooling in a climatic chamber. There were no differences in exercise duration (mean difference=0.10 minutes; 95% CI -5.98 to 6.17 minutes or end exercise rectal temperature (mean difference=0.10°C [0.18°F]; 95% CI -0.05°C to 0.25°C [-0.09°F to 0.45°F] between tarp-assisted cooling (48.47 minutes [SD 8.27 minutes]; rectal temperature 39.73°C [103.51°F], SD 0.27°C [0.49°F]) and passive cooling (48.37 minutes [SD 7.10 minutes]; 39.63°C [103.33°F], SD 0.40°C [0.72°F]). Cooling time to rectal temperature 38.25°C (100.85°F) was significantly faster in tarp-assisted cooling (10.30 minutes [SD 1.33 minutes]) than passive cooling (42.78 [SD 5.87 minutes]). Cooling rates for tarp-assisted cooling and passive cooling were 0.17°C/min (0.31°F/min), SD 0.07°C/min (0.13°F/min) and 0.04°C/min (0.07°F/min), SD 0.01°C/min (0.02°F/min), respectively (mean difference=0.13°C [0.23°F]; 95% CI 0.09°C to 0.17°C [0.16°F to 0.31°F]. No sex differences were observed in tarp-assisted cooling rates (men 0.17°C/min [0.31°F/min], SD 0.07°C/min [0.13°F/min]; women 0.16°C/min [0.29°F/min], SD 0.07°C/min [0.13°F/min]; mean difference=0.02°C/min [0.04°F/min]; 95% CI -0.06°C/min to 0.10°C/min [-0.11°F/min to 0.18°F/min]). Women (0.04°C/min [0.07°F/min], SD 0.01°C/min [0.02°F/min]) had greater cooling rates than men (0.03°C/min [0.05°F/min], SD 0.01°C/min [0.02°F/min]) in passive cooling, with negligible clinical effect (mean difference=0.01°C/min [0.02°F/min]; 95% CI 0.001°C/min to 0.024°C/min [0.002°F/min to 0.04°F/min]). Body mass was moderately negatively correlated with the cooling rate in passive cooling (r=-0.580) but not in tarp-assisted cooling (r=-0.206). In the absence of a stationary cooling method such as cold-water immersion, tarp-assisted cooling can serve as an alternative, field-expedient method to provide on-site cooling with a satisfactory cooling rate.

Влияние повторных циклов ритмических экстремальных холодовых воздействий (–120°С) на структурное состояние миокарда в динамике старения крыс

Влияние повторных циклов ритмических экстремальных холодовых воздействий (–120°С) на структурное состояние миокарда в динамике старения крыс

Comparison of selective head cooling versus whole‐body cooling

This study compared selective head cooling (SHC) and whole-body cooling (WBC) in newborns with hypoxic-ischemic encephalopathy (HIE). We conducted a prospective randomized small-scale pilot study in newborns with HIE, born after >35 weeks of gestation. The patients were randomly assigned to receive SHC or WBC. The SHC group consisted of 17 patients, and the WBC group, 12 patients. There was no significant difference in adverse effects related to cooling therapy between the two groups. During the 12 month study period, seven patients in the SHC group and four in the WBC group died, but the difference was not significant (P = 0.667). Among the patients alive at 12 months after treatment, six in the SHC group and four in the WBC group had severe disabilities; the difference was not significant (P = 0.671). When the composite outcome of death or severe disability was evaluated, the difference between the SHC group (77%, n = 13) and the WBC group (67%, n = 8) was not significant (P = 0.562). Moreover, the number of survivors without disability at 12 months after treatment did not differ significantly between the SHC group (n = 3) and the WBC group (n = 4; P = 0.614). There were no significant differences in adverse effects, 12 month neuromotor development, or mortality rate between SHC and WBC in newborns with HIE, born after >35 weeks of gestation.

The effects of selective head cooling versus whole-body cooling on some neural and inflammatory biomarkers: a randomized controlled pilot study.

BackgroundTherapeutic hypothermia (TH) has become standard care in newborns with moderate to severe hypoxic ischemic encephalopathy (HIE), and the 2 most commonly used methods are selective head cooling (SHC) and whole body cooling (WBC). This study aimed to determine if the effects of the 2 methods on some neural and inflammatory biomarkers differ.Materials and methodsThis prospective randomized pilot study included newborns delivered after >36 weeks of gestation. SHC or WBC was administered randomly to newborns with moderate to severe HIE that were prescribed TH. The serum interleukin (IL)-1β, IL-6, neuron-specific enolase (NSE), brain-specific creatine kinase (CK-BB), tumor necrosis factor-alpha (TNF-α), and protein S100 levels, the urine S100B level, and the urine lactate/creatinine (L/C) ratio were evaluated 6 and 72 h after birth. The Bayley Scales of Infant and Toddler Development-III was administered at month 12 for assessment of neurodevelopmental findings.ResultsThe SHC group included 14 newborns, the WBC group included 10, the mild HIE group included 7, and the control group included 9. All the biomarker levels in the SHC and WBC groups at 6 and 72 h were similar, and all the changes in the biomarker levels between 6 and 72 h were similar in both groups. The serum IL-6 and protein S100 levels at 6 h in the SHC and WBC groups were significantly higher than in the control group. The urine L/C ratio at 6 h in the SHC and WBC groups was significantly higher than in the mild HIE and control groups. The IL-6 level and L/C ratio at 6 and 72 h in the patients that had died or had disability at month 12 were significantly higher than in the patients without disability at month 12.ConclusionThe effects of SHC and WBC on the biomarkers evaluated did not differ. The urine L/C ratio might be useful for differentiating newborns with moderate and severe HIE from those with mild HIE. Furthermore, the serum IL-6 level and the L/C ratio might be useful for predicting disability and mortality in newborns with HIE.

Resuscitation with whole body cooling prevents multiple organ damage after hemorrhagic shock in rats

Whole body cooling (WBC) has been shown to improve survival in hemorrhagic shock (HS) rat studies. We hypothesized that induction of WBC would be beneficial for multiple organ damage (MOD) during HS resuscitation. Light anesthesia was induced with ketamine in rats, and spontaneous breathing was maintained. Rectal temperature (Tr) was monitored at about 36oC. HS was induced by blood withdrawal of 6ml/100g body weight during a 60‐minute period, following by blood transfusion for a 30‐minute period. Immediately after blood transfusion, rats were randomized into three groups of 10 rats each: group 1, untreated HS rats maintained at Tr 36.5oC; group 2, HS rats maintained to Tr 37.5oC (with 36oC water blanket temperature); and group 3, HS rats maintained to Tr 34oC (with 16oC water blanket temperature). Rats were controlled at each target Tr for 30 min. It was found that resuscitation with blood, but not WBC, induced significant multiple organ dysfunction, manifested by a high plasma level of aspartate aminotransferase, alanine aminotransferase, blood urea nitrogen, creatinine, and lactate dehydrogenase. In addition, HS rats received blood transfusion alone has significant MOD, evidenced by a high score of lung, kidney, or liver. The MOD caused by HS were significantly attenuated by WBC, in particular with the 16oC WBC. Our data indicate that resuscitation with WBC prevents multiple organ dysfunction or damage after acute HS in rats.

Impact of warmed inhaled gas from the mechanical ventilator on esophageal temperature during therapeutic whole body hypothermia

During therapeutic whole body cooling (WBC), the core temperature is usually monitored with an esophageal probe. Most infants receive mechanical ventilation while being cooled. As the temperature in the esophagus responds rapidly to changes in the ambient temperature, inhalation of warmed gas from ventilator may lead to overestimation of ventilated patients' actual temperature, causing automated cooling devices to overcool patients well below the desired set temperature targets. To determine if the esophageal temperature recordings during therapeutic WBC differ between ventilated and non-ventilated infants. Twenty-two consecutively cooled infants had simultaneous esophageal and rectal temperatures recorded every 4 h during 72 h of WBC. Other clinical monitoring and treatment during hypothermia were provided under an established protocol. Fourteen infants received mechanical ventilation throughout the duration of cooling. The remaining eight infants were initially ventilated but were extubated later and were not on ventilator between 32 and 72 h of WBC. The esophageal temperatures across every 4 h time points during the 32-72 h interval of WBC did not differ between the ventilated and non-ventilated infants. The magnitude (median, interquartile range) of the difference between esophageal and rectal temperatures was also similar between the two groups. Warmed inhaled gas does not interfere with the esophageal temperature during WBC.

The Effect of Whole-Body Cooling on Hematological and Coagulation Parameters in Asphyxic Newborns

Although moderate therapeutic hypothermia is the only proven neuroprotective therapy in neonatal hypoxic ischemic encephalopathy secondary to perinatal asphyxia (PA), there is lack of data for its effect on hemostasis. To investigate the effect of neonatal asphyxia on hemostasis and to evaluate the effect of whole body cooling on hematological parameters. Hematological parameters evaluated on the first day of patients with PA before start of hypothermia were compared with those of healthy controls. The effects of whole body cooling on the same parameters were also evaluated on the fourth day. A total of 17 neonates with PA and 15 healthy controls were included. Mean values for prothrombin time (PT), international normalized ratio (INR), activated partial thromboplastin time (aPTT), and d-dimer obtained on the first day were significantly higher in the PA group compared to healthy controls (P ≤ .001 for all comparisons), whereas platelet count, levels of fibrinogen, factors II, V, VII, IX, X, and XI were significantly lower (P ≤ .005 for all comparisons). Levels of factor XIII were normal in both groups. In the study group, mean values for PT, INR, aPTT, and d-dimer evaluated on postnatal day 4 were significantly lower compared to values obtained on the first day of birth in PA group (P < .05 for all comparisons), with statistically significant increases in mean levels of fibrinogen, factor II, V, VII, IX, X, and XII (P < .05 for all comparisons). PA results in significant reductions in levels of factors of the extrinsic pathway and has been associated with thrombocytopenia and disseminated intravascular coagulation. Hypothermia may actually improve the clinical picture in such patients rather than aggravating the hemostatic disturbance, particularly with the implementation of supportive treatment.

1106 Impact of Warmed Inhaled Gas from the Mechanical Ventilator on Esophageal Temperature During Whole Body Hypothermia for Hypoxic-Ischemic Encephalopathy

During whole body cooling (WBC), the core temperature is monitored with either an esophageal or a rectal probe. Most infants are usually on mechanical ventilation while receiving hypothermia. As the...