• 대한약리학회지
• /
• 제19권1호
• /
• pp.61-69
• /
• 1983

Hypothermia is an essential preparatory procedure for cardiac surgery, which lows the metabolic rate and myocardial oxygen demand. However, hypothermia itself is a stress enough to change the tonus of sympathoadrenal system, especially the cardiovascular responses to the catecholamines. It is reported that the positive chronotropic and inotropic response of catecholamines is exaggerated during hypothermia because of decreased norepinephrine uptake at the junctional cleft or decreased catecholamine metabolism. On the other hand, there are evidences of diminished catecholamines responses in low temperature ana further, interconversion of adrenergic receptors is also suggested. Present investigation was planned to observe the cardiovascular changes and its responses to catecholamines during surface hypothermia in cat. Healthy mongrel cats, weighing $2{\sim}3\;kg$, anesthetized with secobarbital(30 mg/kg), were permitted to hypothermia by external cooling technic. Esophageal temperature, ECG (lead II), heart rate, left ventricular pressure with dP/dt, carotid artery pressure and left ventricular contractile force were monitored with Polygragh (Model 7, Grass), and the respiration was maintained with artificial respirator (V 5 KG, Narco). Followings are summarized results. 1) Surface cooling caused progressive decrease of body temperature and reached $l8.8{\pm}0.8^{\circ}C$ and $16.9{\pm}0.6^{\circ}C$ in 120 and 150 min respectively, after immersion into ice water, and ventricular fibrillation was developed at $20.4{\pm}0.65^{\circ}C$. 2) Heart rate, blood pressure and myocardial contractility were decreased after initial increase as the body temperature falls. 3) Systolic and diastolicdd P/dt of left ventricular pressure were decreased and that the decrement of diastolic dP/dt was more marked. 4) On ECG, ST depression, Twave inversion and prolongation of PR interval were prominent in hypothermia, and moreover, the prolongation of PR interval was marked just prior to the development of ventricular fibrillation. 5) The cardiovascular responses to catecholamines, especially to isoproterenol, were suppressed under hypothermia.

• Child Health Nursing Research
• /
• 제23권4호
• /
• pp.505-514
• /
• 2017

Purpose: Maintaining body temperature is a key vital function of human beings, but little is known about how body temperature of highrisk infants is sustained during early life after birth. The aim of this study was to describe hypothermia in high-risk infants during their first week of life and examine demographic, environmental, and clinical attributors of hypothermia. Methods: A retrospective longitudinal study was done from January 1, 2013 to December 31, 2015. Medical records of 570 high-risk infants hospitalized at Neonatal Intensive Care Units (NICU) of a university affiliated hospital were examined. Body temperature and related factors were assessed for seven days after birth. Results: A total of 336 events of hypothermia (212 mild and 124 moderate) occurred in 280 neonates (49.1%) and most events (84.5%) occurred within 24 hours after birth. Logistic regression analysis revealed that phototherapy (aOR=0.28, 95% CI=0.10-0.78), Apgar score at 5 minute (aOR=2.20, 95% CI=1.17-4.12), and intra-uterine growth retardation or small for gestational age (aOR=3.58, 95% CI=1.69-7.58) were statistically significant contributors to hypothermia. Conclusion: Findings indicate that high-risk infants are at risk for hypothermia even when in the NICU. More advanced nursing interventions are necessary to prevent hypothermia of high-risk infants.

• Journal of Korean Neurosurgical Society
• /
• 제30권sup2호
• /
• pp.316-321
• /
• 2001

Objectives : The goal of this study is to evaluate the usefulness of mild hypothermia treatment in patients with increased intracranial pressure(ICP). Material and Method : From November 1999 to May 2001, 11 patients were treated with mild hypothermia ($32-34^{\circ}C$) in whom ICP maintained at higher than 20mmHg in spite of decompressive surgery and high dose barbiturate therapy. The patient's rectal temperature were lowered by external cooling. Hypothermia was maintained for not more than 7 days and then the patients were rewarmed slowly for 24 hours. If increased ICP persisted for 2 days of hypothermia, this treatment was continued for several days. The functional outcome of each patient was assessed according to Glasgow Outcome Scale(GOS). Results : All cases except two cases showed decrease of ICP after hypothermia therapy. In 1 case which was right middle cerebral artery(MCA) infarct, ICP re-increased after 24 hours and in another 1 case, ICP was not controlled initially. Among 11 cases, 3 cases showed favorable outcome. Conclusion : Mild hypothermia treatment in patients with increased ICP was effective in controlling ICP and mortality was so decreased. More clinical experience and controlled study was need to determine the effectiveness.

• Journal of Chest Surgery
• /
• 제10권1호
• /
• pp.124-132
• /
• 1977

A experimental study of deep hypothermia for open heart surgery in 5 dogs was reviewed. Surface hypothermia in combination with limited cardiopulmonary bypass was employed. Circulatory dynamics were well maintained following cardiac arrest during one hour at $20^{\circ}C$. Some degree of acidosis usually developed after the arrest period but was gradually corrected during. rewarming Total circulatory occlusion could be maintained for at least one hour at $20^{\circ}C$ without evidence of cerebral damage in the dogs. Potassium in the serum after deep hypothermia was moderately decreased and it was the most severe change in the electrolyte. Free hemoglobin of serum was mild increased and it was one of advantages of combined hypothermia with limited cardiopulmonary bypass.

• Journal of Korean Neurosurgical Society
• /
• 제39권3호
• /
• pp.228-230
• /
• 2006

Hypothermia is relatively a common condition and most cases involve mild hypothermia. But severe hypothermia below $30^{\circ}C$ is medical an emergency condition. We report the case of a 41-year-old man who had been left in a manhole for more than 9 hours on a freezing cold water. He was transported to our emergency room in semicomatose state with a body temperature $26.5^{\circ}C$. The patient was warmed with active rewarming. After initial stabilization, the patient was taken for a brain computed tomography and found to have large fronto-temporo-parietal[FTP] subdural hemorrhage. The patient underwent an emergent decompressive craniectomy and hematoma evacuation. After surgery, he recovered to drowsy mentation and vital signs were stable.

• Investigative Magnetic Resonance Imaging
• /
• 제22권1호
• /
• pp.56-60
• /
• 2018

Therapeutic hypothermia in cardiac arrest patients is associated with favorable outcomes mediated via neuroprotective mechanisms. We report a rare case of a 32-year-old male who demonstrated complete recovery of signal changes on perfusion-weighted imaging after therapeutic hypothermia due to cardiac arrest. Brain MRI with perfusion-weighted imaging, performed three days after ending the hypothermia therapy, showed a marked decrease in relative cerebral blood flow (rCBF) and delay in mean transit time (MTT) in the bilateral basal ganglia, thalami, brain stem, cerebellum, occipitoparietal cortex, and frontotemporal cortex. However, no cerebral ischemia was not noted on diffusion-weighted imaging (DWI) or fluid-attenuated inversion recovery (FLAIR) sequences. A follow-up brain MRI after one week showed complete resolution of the perfusion deficit and the patient was discharged without any neurologic sequelae. The mechanism and interpretation of the perfusion changes in cardiac arrest patients treated with therapeutic hypothermia are discussed.

• Natural Product Sciences
• /
• 제12권1호
• /
• pp.14-18
• /
• 2006

The effect(s) of the volatile oil (VO) of Nigella sativa and its two components, ${\alpha}-pinene$ and ${\rho}-cymene$ on body temperature of male and female conscious mice were studied. Further investigations to delineate the mechanism(s) of action of the observed effect(s) by using various blockers involved in the central regulation of body temperature were made. VO and ${\alpha}-pinene$ caused significant reductions in rectal body temperature at is and 30 minute after treatment. ${\rho}-cymene$ had negligible effect on body temperature of mice. Cyproheptadine inhibited VO and ${\alpha}-pinene-induced$ hypothermia significantly. Nalbuphine inhibited ${\alpha}-pinene-induced$ hypothermia significantly but did not affect VO-induced hypothermia. Droperidol potentiated VO and ${\alpha}-pinene-induced$ hypothermia to a non-significant level; whereas atropine potentiated VO-induced hypothermia non-significantly. The study confirms further the role of serotoninergic receptors in the mechanism(s) of the observed pharmacological effects of the VO of Nigella sativa. It also indicated a possible role of opioid receptors in ${\alpha}-pinene-induced$ hypothermia.

• Child Health Nursing Research
• /
• 제18권4호
• /
• pp.164-169
• /
• 2012

Purpose: The purpose of this study was to compare the effectiveness for infants of antifebrile therapy using a hypothermia blanket or rectal antipyretics following open heart surgery. Methods: This was a retrospective study and 174 infants who had open heart surgery at P University Hospital, and whose body temperature body temperature exceeded $37.2^{\circ}C$ were included in the study. The assessment tool was composed of 32 items was used for assessment of fever therapy, physiological indexes and antifebrile duration. Physiological indexes included systolic blood pressure, diastolic blood pressure, heart rate, pH, $PaCO_2$, $PaO_2$, $HCO_3{^-}$, $SaO_2$, and $K^+$ and the antifebrile duration was minutes from having a fever until BT returned to normal levels. Results: The antifebrile duration with the hypothermia blanket was shorter than with rectal antipyretics. There were significant differences in the physiological indexes with either type of antifebrile therapy, but drop in BT was greater with the hypothermia blanket than rectal antipyretics. Conclusion: The results of this study indicate that a hypothermia blanket is a non-invasive, non-drug and safe antifebrile therapy. Therefore, a hypothermia blanket can be applied to infants with a fever following open heart surgery.

• Journal of Korean Neurosurgical Society
• /
• 제29권2호
• /
• pp.167-179
• /
• 2000

Objective : We studied to clarify the effective time zone of mild hypothermic neural protection during ischemia and/or reperfusion after middle cerebral artery occlusion. Methods : In a reversible cerebral infarct model which maintained reperfusion of blood flow after middle cerebral artery occlusion for two hours, the size of cerebral infarction, cerebral edema and the extent of neurological deficit were observed and analyzed for comparison between the control and the experimental groups under hypothermia($33.5^{\circ}C$). The temporalis muscle temperature was reduced to $33.5^{\circ}C$ by surface cooling for two hours during middle cerebral artery occlusion for study group I. The following groups applied hypothermia for two-hour periods after reperfusion : group II(0-2 hours), group III(2-4 hours), and group IV(4-6 hours). They were rewarmed to $36.5^{\circ}C$ until sacrified at 2, 4, 6, 12, and 24 hours after reperfusion. Control group was maintained at normothermia without hypothermia. Results : In the experimental groups with hypothermia, the average value of the size of cerebral infarction($mean{\pm}SD$) was $1.97{\pm}1.65%$, which was a remarkable reduction over that of the control, $4.93{\pm}3.79%$. In the control, a progressive increase was shown in the size of infarction from point of reperfusion to 6 hours after reperfusion without further changes in size afterward. Intra-ischemic hypothermia(group I) prevented ischemic injury but did not prevent reperfusion injury. Group II examplified the most neural protective effect in comparison to the control group and group IV(p<0.05). The cortex was more vulnerable to reperfusion injury than the subcortex. Mild hypothermia showed more neural protective effects on the cortex than subcortex. Conclusion : The most appropriate time zone for application of mild hypothermia was defined to be within four hours following reperfusion.

• Journal of Korean Biological Nursing Science
• /
• 제19권3호
• /
• pp.123-130
• /
• 2017

Purpose: This study aimed to identify factors influencing intra-operative core body temperature (CBT), and to develop a predictive model for intra-operative CBT in laparoscopic abdominal surgery. Methods: The prospective observational study involved 161 subjects, whose age, weight, and height were collected. The basal pre-operative CBT, pre-operative blood pressure, and heartbeat were measured. CBT was measured 1 hour and 2 hours after pneumoperitoneum. Results: Explanatory factors of intra-operative hypothermia (< $36^{\circ}C$) were weight (${\beta}=.361$, p< .001) and pre-operative CBT (${\beta}=.280$, p= .001) 1 hour after pneumoperitoneum (Adjusted $R^2=.198$, F= 7.56, p< .001). Weight was (${\beta}=.423$, p< .001) and pre-operative CBT was (${\beta}=.206$, p= .011) 2 hours after pneumoperitoneum (Adjusted $R^2=.177$, F= 5.93, p< .001). The researchers developed a predictive model for intra-operative CBT ($^{\circ}C$) by observing intra-operative CBT, body weight, and pre-operative CBT. The predictive model revealed that intra-operative CBT was positively correlated with body weight and pre-operative CBT. Conclusion: Influence of weight on intra-operative hypothermia increased over time from 1 hour to 2 hours after pneumoperitoneum, whereas influence of pre-operative CBT on intraoperative hypothermia decreased over time from 1 hour to 2 hours after pneumoperitoneum. The research recommends pre-warming for laparoscopic surgical patients to guard against intra-operative hypothermia.