1
|
Wu TW, Schmicker R, Wood TR, Mietzsch U, Comstock B, Heagerty PJ, Rao R, Gonzalez F, Juul S, Wu YW. Esophageal Versus Rectal Temperature Monitoring During Whole-Body Therapeutic Hypothermia for Hypoxic-Ischemic Encephalopathy: Association with Short- and Long-Term Outcomes. J Pediatr 2024; 268:113933. [PMID: 38309524 PMCID: PMC11045319 DOI: 10.1016/j.jpeds.2024.113933] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Revised: 01/13/2024] [Accepted: 01/29/2024] [Indexed: 02/05/2024]
Abstract
OBJECTIVE To compare the short- and long-term outcomes of infants with hypoxic-ischemic encephalopathy (HIE) treated with whole-body therapeutic hypothermia (TH), monitored by esophageal vs rectal temperature. STUDY DESIGN We conducted a secondary analysis of the multicenter High-Dose Erythropoietin for Asphyxia and Encephalopathy (HEAL) trial. All infants had moderate or severe HIE and were treated with whole-body TH. The primary outcome was death or neurodevelopmental impairment (NDI) at 22-36 months of age. Secondary outcomes included seizures, evidence of brain injury on magnetic resonance imaging, and complications of hypothermia. Logistic regression was used with adjustment for disease severity and site as clustering variable because cooling modality differed by site. RESULTS Of the 500 infants who underwent TH, 294 (59%) and 206 (41%) had esophageal and rectal temperature monitoring, respectively. There were no differences in death or NDI, seizures, or evidence of injury on magnetic resonance imaging between the 2 groups. Infants treated with TH and rectal temperature monitoring had lower odds of overcooling (OR 0.52, 95% CI 0.34-0.80) and lower odds of hypotension (OR 0.57, 95% CI 0.39-0.84) compared with those with esophageal temperature monitoring. CONCLUSIONS Although infants undergoing TH with esophageal monitoring were more likely to experience overcooling and hypotension, the rate of death or NDI was similar whether esophageal monitoring or rectal temperature monitoring was used. Further studies are needed to investigate whether esophageal temperature monitoring during TH is associated with an increased risk of overcooling and hypotension.
Collapse
Affiliation(s)
- Tai-Wei Wu
- Division of Neonatology, Department of Pediatrics, Fetal and Neonatal Institute, Children's Hospital Los Angeles, Keck School of Medicine, University of Southern California, Los Angeles, California.
| | - Robert Schmicker
- Department of Biostatistics, University of Washington, Seattle, Washington
| | - Thomas R Wood
- Division of Neonatology, Department of Pediatrics, University of Washington School of Medicine, Seattle, Washington
| | - Ulrike Mietzsch
- Division of Neonatology, Department of Pediatrics, University of Washington School of Medicine, Seattle, Washington; Division of Neonatology, Department of Pediatrics, Seattle Children's Hospital, Seattle, Washington
| | - Bryan Comstock
- Department of Biostatistics, University of Washington, Seattle, Washington
| | - Patrick J Heagerty
- Department of Biostatistics, University of Washington, Seattle, Washington
| | - Rakesh Rao
- Department of Pediatrics, Washington University in St Louis, St Louis, Missouri
| | - Fernando Gonzalez
- Department of Pediatrics, University of California San Francisco, San Francisco, California
| | - Sandra Juul
- Division of Neonatology, Department of Pediatrics, University of Washington School of Medicine, Seattle, Washington; Division of Neonatology, Department of Pediatrics, Seattle Children's Hospital, Seattle, Washington
| | - Yvonne W Wu
- Department of Neurology, University of California San Francisco, San Francisco, California
| |
Collapse
|
2
|
Wu TW, Wisnowski JL, Geisler RF, Reitman A, Ho E, Tamrazi B, Chapman R, Blüml S. An In Vivo Assessment of Regional Brain Temperature during Whole-Body Cooling for Neonatal Encephalopathy. J Pediatr 2020; 220:73-79.e3. [PMID: 32089332 PMCID: PMC7265905 DOI: 10.1016/j.jpeds.2020.01.019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 12/05/2019] [Accepted: 01/10/2020] [Indexed: 12/25/2022]
Abstract
OBJECTIVE 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. STUDY DESIGN 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. RESULTS In total, 53 infants were enrolled (31 girls, mean gestational age: 38.6 ± 2 weeks; mean birth weight: 3243 ± 613 g). MR spectroscopy was acquired at mean age of 2.2 ± 0.6 days. A total of 201 MR spectra were included in the analysis. The thalamus, the deepest structure (36.4 ± 2.3 mm 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 ± 2.2 mm) 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). CONCLUSIONS Whole-body hypothermia was effective in cooling deep brain structures, whereas superficial structures were warmer, with temperatures significantly greater than rectal temperatures.
Collapse
Affiliation(s)
- Tai-Wei Wu
- Fetal and Neonatal Institute, Division of Neonatology, Children's Hospital Los Angeles, Los Angeles, CA; Department of Pediatrics, Keck School of Medicine, University of Southern California, Los Angeles, CA.
| | - Jessica L. Wisnowski
- Department of Radiology, Children’s Hospital Los Angeles, Keck School of Medicine, University of Southern California, Los Angeles, CA;,Rudi Schulte Research Institute, Santa Barbara, CA
| | - Robert F. Geisler
- Division of Neonatology, Children’s Hospital, Fetal and Neonatal Institute, Los Angeles
| | - Aaron Reitman
- Division of Neonatology, Children’s Hospital, Fetal and Neonatal Institute, Los Angeles
| | - Eugenia Ho
- Division of Neurology, Children’s Hospital Los Angeles, Los Angeles, CA
| | - Benita Tamrazi
- Department of Radiology, Children’s Hospital Los Angeles, Keck School of Medicine, University of Southern California, Los Angeles, CA
| | - Rachel Chapman
- Division of Neonatology, Children’s Hospital, Fetal and Neonatal Institute, Los Angeles;,Department of Pediatrics, Keck School of Medicine, University of Southern California
| | - Stefan Blüml
- Department of Radiology, Children’s Hospital Los Angeles, Keck School of Medicine, University of Southern California, Los Angeles, CA;,Rudi Schulte Research Institute, Santa Barbara, CA
| |
Collapse
|
3
|
Jung DE, Ritacco DG, Nordli DR, Koh S, Venkatesan C. Early Anatomical Injury Patterns Predict Epilepsy in Head Cooled Neonates With Hypoxic-Ischemic Encephalopathy. Pediatr Neurol 2015; 53:135-40. [PMID: 26047693 PMCID: PMC4729358 DOI: 10.1016/j.pediatrneurol.2015.04.009] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Revised: 04/14/2015] [Accepted: 04/16/2015] [Indexed: 11/16/2022]
Abstract
BACKGROUND Our aim was to determine whether early anatomical injury patterns on magnetic resonance imaging-correlate with the development of postneonatal epilepsy in infants treated with selective head cooling for hypoxic-ischemic encephalopathy. METHODS We retrospectively analyzed infants ≥35 weeks' gestation born between 2008 and 2013 and followed for at least one year at Northwestern University. All had brain magnetic resonance imaging scans at days 4-5 and electroencephalographs during rewarming and at 3 to 6 months of age. RESULTS Outcome was favorable for our cohort of 73 individuals with a mean follow-up of 41 (±7) months. The majority (66%) survived with no seizure recurrence, whereas 13 (18%) developed postneonatal epilepsy, including eight who had infantile spasms. Twelve infants (16%) died. The most common magnetic resonance imaging pattern was diffuse brain injury involving both cortical and subcortical gray matter (26/73, 35%), followed by cortical and subcortical white matter injury (18/73, 25%) and normal magnetic resonance imaging (16/73, 22%). In 13 infants (18%), the brainstem was involved in addition to cortical and subcortical gray matter; nine died and all four surviving infants developed infantile spasms. All 18 infants with cortical and subcortical white matter injury survived and none developed postneonatal epilepsy. The risk of postneonatal epilepsy was associated with injury involving subcortical regions (basal ganglia, thalamus ± brainstem) (12/39 versus 1/34, P < 0.003). CONCLUSIONS Brainstem injury was highly predictive of infantile spasms, whereas cortical injury alone predicted low risk for short-term postneonatal epilepsy. Location of anatomical injury on magnetic resonance imaging can be an early predictive factor for development of infantile spasms and inform prognostic decisions in newborns treated with selective head cooling for hypoxic-ischemic encephalopathy.
Collapse
Affiliation(s)
- Da Eun Jung
- Department of Pediatrics, Division of Neurology & Epilepsy, Ann & Robert H. Lurie Children’s Hospital of Chicago, and the Northwestern University Feinberg School of Medicine, Chicago, Illinois, U.S.A
| | - David G. Ritacco
- Department of Pediatrics, Division of Neurology & Epilepsy, Ann & Robert H. Lurie Children’s Hospital of Chicago, and the Northwestern University Feinberg School of Medicine, Chicago, Illinois, U.S.A
| | - Douglas R. Nordli
- Department of Pediatrics, Division of Neurology & Epilepsy, Ann & Robert H. Lurie Children’s Hospital of Chicago, and the Northwestern University Feinberg School of Medicine, Chicago, Illinois, U.S.A
| | - Sookyong Koh
- Department of Pediatrics, Division of Neurology & Epilepsy, Ann & Robert H. Lurie Children’s Hospital of Chicago, and the Northwestern University Feinberg School of Medicine, Chicago, Illinois, U.S.A
| | - Charu Venkatesan
- Department of Pediatrics, Division of Neurology & Epilepsy, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, Illinois; The Northwestern University Feinberg School of Medicine, Chicago, Illinois.
| |
Collapse
|
4
|
Hoque N, Liu X, Chakkarapani E, Thoresen M. Minimal systemic hypothermia combined with selective head cooling evaluated in a pig model of hypoxia-ischemia. Pediatr Res 2015; 77:674-80. [PMID: 25665052 DOI: 10.1038/pr.2015.31] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2014] [Accepted: 11/03/2014] [Indexed: 11/09/2022]
Abstract
BACKGROUND Selective head cooling (SHC) with moderate hypothermia (HT) and whole-body cooling are beneficial following perinatal asphyxia. SHC with systemic normothermia (NT) or minimal HT is under-investigated, could obviate systemic complications of moderate HT, and be applicable to preterm infants. We hypothesized that minimal systemic HT with SHC following hypoxia-ischemia (HI) would be neuroprotective compared with systemic NT. METHODS Newborn pigs underwent global HI causing permanent brain injury before being randomized to NT (rectal temperature (Trectal) 38.5 °C) or minimal HT (Trectal 37.0 °C) with SHC (cooling cap and body wrap) for 48 h followed by 24-h NT with 72-h survival. RESULTS SHC did not reduce global or regional neuropathology score when correcting for insult severity or compared with a NT group matched for HI severity but increased mortality by 26%. During 48 h, the SHC mean ± SD Trectal was 37.0 ± 0.2 °C, and Tdeep brain and Tsuperficial brain were 35.0 ± 1.1 °C and 31.5 ± 1.6 °C, respectively, with stable Tbrain achieved ≥ 3 h after starting cooling. CONCLUSION This is the first study in newborn pigs of minimal systemic HT with SHC for 48 h and a further 24 h of NT following HI. Mortality was increased in the cooled group with no neuroprotection in survivors.
Collapse
Affiliation(s)
- Nicholas Hoque
- Neonatal Neuroscience, School of Clinical Sciences, University of Bristol, Bristol, Avon, UK
| | - Xun Liu
- Neonatal Neuroscience, School of Clinical Sciences, University of Bristol, Bristol, Avon, UK
| | - Ela Chakkarapani
- Neonatal Neuroscience, School of Clinical Sciences, University of Bristol, Bristol, Avon, UK
| | - Marianne Thoresen
- 1] Neonatal Neuroscience, School of Clinical Sciences, University of Bristol, Bristol, Avon, UK [2] Department of Physiology, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| |
Collapse
|
5
|
Bainbridge A, Kendall GS, De Vita E, Hagmann C, Kapetanakis A, Cady EB, Robertson NJ. Regional neonatal brain absolute thermometry by 1H MRS. NMR IN BIOMEDICINE 2013; 26:416-423. [PMID: 23074155 DOI: 10.1002/nbm.2879] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2012] [Revised: 08/28/2012] [Accepted: 09/04/2012] [Indexed: 06/01/2023]
Abstract
Therapeutic hypothermia is standard care for infants with moderate to severe encephalopathy. (1) H MRS thermometry (MRSt) measures regional brain absolute temperature using the temperature-dependent water chemical shift. This study evaluates the clinical feasibility of MRSt in human neonates, and correlates white matter (WM) and thalamus (Thal) MRSt with conventional rectal temperature (Trectal ) measurement. Fifty-six infants born at term underwent perinatal MRSt for suspected hypoxic-ischaemic brain injury and 33 infants born preterm had MRSt at a term-equivalent age; 56 of the 89 had Trectal measured after MRSt of either a Thal or posterior WM voxel, or both. MRSt used point-resolved spectroscopy (no water suppression; TR = 1370 ms; TE = 288 ms; 1.5 × 1.5 × 1.5 cm(3) Thal and 1.1 × 1.3 × 1.4 cm(3) WM voxels). Time domain data were phase and frequency corrected before summation and motion-corrupted data were excluded from further analysis using simple criteria [preprocessing + quality assurance (QA)]. Two published water temperature-dependence calibrations [both using cerebral creatine (Cr), choline (Cho) and N-acetylaspartate (Naa) as independent reference peaks] were compared. The temperature measurements derived from Cr, Cho and Naa were combined to give a single amplitude-weighted combination temperature (TAWC ). WM and Thal TAWC correlated linearly with Trectal (Thal slope, 0.82 ± 0.04, R(2) = 0.85, p < 0.05; WM slope, 0.95 ± 0.04, R(2) = 0.78, p < 0.05). Preprocessing + QA improved the correlation between WM TAWC and Trectal (R(2) increased from 0.27 to 0.78, p < 0.001). Both calibration datasets showed specific inconsistencies between the temperatures calculated using Cr, Cho and Naa reference peaks when applied to this neonatal dataset. Neonatal MRSt is clinically feasible. Preprocessing + QA improved MRSt reliability in WM. The consideration of MRSt calibration internal biases is necessary before combining MRSt temperatures from multiple reference peaks to obtain TAWC.
Collapse
Affiliation(s)
- Alan Bainbridge
- Medical Physics and Bioengineering, University College London Hospitals NHS Foundation Trust, London, UK
| | | | | | | | | | | | | |
Collapse
|
6
|
Qiu W, Shen H, Zhang Y, Wang W, Liu W, Jiang Q, Luo M, Manou M. Noninvasive selective brain cooling by head and neck cooling is protective in severe traumatic brain injury. J Clin Neurosci 2007; 13:995-1000. [PMID: 17113984 DOI: 10.1016/j.jocn.2006.02.027] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2005] [Accepted: 02/17/2006] [Indexed: 11/22/2022]
Abstract
Therapeutic hypothermia is a promising treatment for patients with severe traumatic brain injury (TBI). We present here the results of a study in which noninvasive selective brain cooling (SBC) was achieved using a head cap and neckband. Ninety patients with severe TBI were divided into a normothermia control group (n=45) and a SBC group (n=45), whose brain temperature was maintained at 33-35 degrees C for 3 days using a combination of head and neck cooling. At 24, 48 and 72h after injury, the mean intracranial pressure (ICP) values of the patients who underwent SBC were lower than those of the normothermia controls (19.14+/-2.33, 19.72+/-1.73 and 17.29+/-2.07 mmHg, versus 23.41+/-2.51, 20.97+/-1.86, and 20.13+/-1.87 mmHg, respectively, P<0.01). There was a significant difference in the neurological recovery of the two groups at the 6-month follow-up after TBI. Good neurological outcome (Glasgow Outcome Scale score of 4 to 5) rates 6 months after injury were 68.9% for the SBC group, and 46.7% for the control group (P<0.05). There were no complications resulting in severe sequelae. In conclusion, the noninvasive SBC described here is a safe method of administering therapeutic hypothermia, which can reduce ICP and improve prognosis without severe complications in patients with severe TBI.
Collapse
Affiliation(s)
- Wusi Qiu
- Brain Center, Department of Neurosurgery, Second Affiliated Hospital, Zhejiang University, School of Medicine, 88 Jiefang Road, Hangzhou 310009, China
| | | | | | | | | | | | | | | |
Collapse
|
7
|
Iwata S, Iwata O, Thornton JS, Shanmugalingam S, Bainbridge A, Peebles D, Wyatt JS, Cady EB, Robertson NJ. Superficial brain is cooler in small piglets: neonatal hypothermia implications. Ann Neurol 2006; 60:578-585. [PMID: 17048261 DOI: 10.1002/ana.20978] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
OBJECTIVE Hypothermia was not neuroprotective in low body weight (BW) infants on subgroup analysis in a recent clinical trial of selective head cooling (SHC) in neonatal encephalopathy (CoolCap Trial). METHODS The BW dependence of regional cerebral temperature was investigated in 14 newborn piglets under normothermia (38.5 degrees C), whole-body cooling (WBC; 36.5, 34.5, 32.5, and 30.5 degrees C), or SHC (20, 15, and 10 degrees C). RESULTS Normothermia: Lower BW led to lower superficial brain temperature (p < 0.01). Deep to superficial brain and rectal to superficial brain temperature gradients increased with decreasing BW (both p < 0.05). WBC: Lower BW led to lower superficial brain temperature and higher rectal to superficial brain temperature gradient (p < 0.05 and p < 0.01, respectively). SHC: For lower BW, superficial and deep brain temperatures decreased (p < 0.01 and p < 0.05, respectively), whereas rectal to deep, rectal to superficial, and deep to superficial brain temperature gradients increased (p < 0.05, p < 0.01, and p < 0.05, respectively). Compared with SHC alone, superimposition of WBC (34.5 degrees C) reduced all regional temperatures (all p < 0.001); gradients were unaffected. INTERPRETATION Brain cooling (under normothermia, WBC, or SHC) was more efficient with lower BW due to greater head surface area-to-volume ratios. In the CoolCap Trial, low BW infants might have been excessively cooled. WBC and SHC may require BW adjustment to accomplish consistent regional temperatures and optimal neuroprotection.
Collapse
Affiliation(s)
- Sachiko Iwata
- Centre for Perinatal Brain Research, Institute for Women's Health, University College London, The Rayne Institute, London, United Kingdom
| | | | | | | | | | | | | | | | | |
Collapse
|
8
|
Iwata O, Thornton JS, Sellwood MW, Iwata S, Sakata Y, Noone MA, O'Brien FE, Bainbridge A, De Vita E, Raivich G, Peebles D, Scaravilli F, Cady EB, Ordidge R, Wyatt JS, Robertson NJ. Depth of delayed cooling alters neuroprotection pattern after hypoxia-ischemia. Ann Neurol 2005; 58:75-87. [PMID: 15984028 DOI: 10.1002/ana.20528] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Hypothermia after perinatal hypoxia-ischemia (HI) is neuroprotective; the precise brain temperature that provides optimal protection is unknown. To assess the pattern of brain injury with 3 different rectal temperatures, we randomized 42 newborn piglets: (Group i) sham-normothermia (38.5-39 degrees C); (Group ii) sham-33 degrees C; (Group iii) HI-normothermia; (Group iv) HI-35 degrees C; and (Group v) HI-33 degrees C. Groups iii through v were subjected to transient HI insult. Groups ii, iv, and v were cooled to their target rectal temperatures between 2 and 26 hours after resuscitation. Experiments were terminated at 48 hours. Compared with normothermia, hypothermia at 35 degrees C led to 25 and 39% increases in neuronal viability in cortical gray matter (GM) and deep GM, respectively (both p < 0.05); hypothermia at 33 degrees C resulted in a 55% increase in neuronal viability in cortical GM (p < 0.01) but no significant increase in neuronal viability in deep GM. Comparing hypothermia at 35 and 33 degrees C, 35 degrees C resulted in more viable neurons in deep GM, whereas 33 degrees C resulted in more viable neurons in cortical GM (both p < 0.05). These results suggest that optimal neuroprotection by delayed hypothermia may occur at different temperatures in the cortical and deep GM. To obtain maximum benefit, you may need to design patient-specific hypothermia protocols by combining systemic and selective cooling.
Collapse
Affiliation(s)
- Osuke Iwata
- Department of Paediatrics and Child Health, Royal Free and University College Medical School, The Rayne Institute, London, UK.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
9
|
Tooley JR, Eagle RC, Satas S, Thoresen M. Significant head cooling can be achieved while maintaining normothermia in the newborn piglet. Arch Dis Child Fetal Neonatal Ed 2005; 90:F262-6. [PMID: 15846020 PMCID: PMC1721873 DOI: 10.1136/adc.2003.044305] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND Hypothermia has been shown to be neuroprotective in animal models of hypoxia-ischaemia. It is currently being evaluated as a potentially therapeutic option in the management of neonatal hypoxic-ischaemic encephalopathy. However, significant hypothermia has adverse systemic effects. It has also recently been found that the stress of being cold can abolish the neuroprotective effects of hypothermia. It is hypothesised that selective head cooling (SHC) while maintaining normal core temperature would enable local hypothermic neuroprotection while limiting the stress and side effects of hypothermia. OBJECTIVE To determine whether it is possible to induce moderate cerebral hypothermia in the deep brain of the piglet while maintaining the body at normothermia (39 degrees C). METHODS Six piglets (<48 hours old) were anaesthetised, and temperature probes inserted into the brain. Temperature was measured at different depths from the brain surface (21 mm (T(deep brain)) to 7 mm (T(superficial brain))). After a 45 minute global hypoxic-ischaemic insult, each piglet was head cooled for seven hours using a cap circulated with cold water (median 8.9 degrees C (interquartile range 7.5-14)) wrapped around the head. Radiant overhead heating was used to warm the body during cooling. RESULTS During SHC it was possible to cool the brain while maintaining a normal core temperature. The mean (SD) T(deep brain) during the seven hour cooling period was 31.1 (4.9) degrees C while T(rectal) remained stable at 38.8 (0.4) degrees C. The mean T(rectal)-T(deep brain) difference throughout the cooling period was 9.8 (6.1) degrees C. The mean T(skin) required was 40.8 (1.1) degrees C. There was no evidence of skin damage secondary to these skin temperatures. During cooling only one piglet shivered. CONCLUSIONS It is possible to maintain systemic normothermia in piglets while significantly cooling the deeper structures of the brain. This method of cooling may further limit the side effects associated with systemic hypothermia and be feasible for premature infants.
Collapse
Affiliation(s)
- J R Tooley
- Department of Child Health, St Michael's Hospital, Southwell Street, Bristol BS2 8EG, UK
| | | | | | | |
Collapse
|
10
|
Inder TE, Hunt RW, Morley CJ, Coleman L, Stewart M, Doyle LW, Jacobs SE. Randomized trial of systemic hypothermia selectively protects the cortex on MRI in term hypoxic-ischemic encephalopathy. J Pediatr 2004; 145:835-7. [PMID: 15580212 DOI: 10.1016/j.jpeds.2004.07.034] [Citation(s) in RCA: 102] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Twenty-six infants with hypoxic-ischemic encephalopathy (HIE) were randomized to normothermia or to systemic hypothermia. The hypothermia group had less cortical gray matter signal abnormality on magnetic resonance imaging (MRI) (1/12 vs 7/14 infants in the normothermic group; P = .036), which may indicate differing regional benefit from systemic hypothermia.
Collapse
Affiliation(s)
- Terrie E Inder
- Division of Newborn Services, Royal Women's Hospital, Neonatal Neurology, Royal Children's Hospital, Melbourne, Australia.
| | | | | | | | | | | | | |
Collapse
|
11
|
Iwata O, Iwata S, Tamura M, Nakamura T, Sugiura M, Ogiso Y, Takashima S. Early head cooling in newborn piglets is neuroprotective even in the absence of profound systemic hypothermia. Pediatr Int 2003; 45:522-9. [PMID: 14521525 DOI: 10.1046/j.1442-200x.2003.01784.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Selective head cooling in the newborn infant has been proposed as a neuroprotective treatment with a lower level of systemic adverse effect than that of systemic hypothermia. However, the efficacy is not confirmed as well as that of systemic hypothermia. In order to analyze the safety and efficacy of selective head cooling, 25 newborn piglets were randomly selected for either normothermic or hypothermic treatment. METHODS Global hypoxic insult was induced by lowering the oxygen concentration to the maximal level to maintain the background electroencephalogram (EEG) voltage under 7 microV for 45 min. The core temperature of normothermic piglets was maintained between 38.5 degrees C and 39 degrees C, while prophylactic cooling was applied to the hypothermic piglets at the same time of the insult. Very mild systemic hypothermia by 1 degrees C was induced in addition to selective head cooling with 10 degrees C coolant temperature. Animals were killed for histopathological examination seven hours after the end of the insult. RESULTS Two normothermic piglets died while all hypothermic piglets survived. Neuropathological findings were significantly severer in the normothermic group than in the hypothermic group. Intracranial pressure was significantly lower, and EEG recovery was significantly better in the hypothermic piglets. There was no significant difference in the lowest oxygen concentration, degrees of acidosis, blood lactate, and blood pressure between the groups, although heart rate was significantly lower in the hypothermic group. CONCLUSIONS We have demonstrated that early head cooling was effective in preventing some of the earliest brain damage due to hypoxic insult even in the absence of profound systemic hypothermia.
Collapse
Affiliation(s)
- Osuke Iwata
- Division of Neonatology, Perinatal Center, Nagano Children's Hospital, Toyoshina, Nagano, Japan.
| | | | | | | | | | | | | |
Collapse
|