• The Korean Journal of Physiology
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• v.30 no.1
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• pp.105-116
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• 1996

Rendering the brain ischemic would evoke the cerebral ischemic reflex which is characterized by an arterial pressor response, apnea and bradycardia. Since the rostral ventrolateral medulla (RVLM) is known to play a key role in the maintenance of normal cardiopulmonary activity, during the cerebral ischemic reflex some cardiac related cells should be excited and respiration related cells inhibited. In this context, the responses of RVLM neurons to systemie and focal hypoxia were analyzed in the present study. Twenty-five adult cats of either sex were anesthetized with ${\alpha}-chloralose$ and the single neuronal activities were identified from RVLM area. For the induction of focal hypoxia in the recording site, sodium cyanide was applied iontophoretically and for systemic hypoxia the animal was ventilated with nitrogen gas for a twenty-second period. Cellular activities were analyzed in terms of their discharge pattern and responses to the hypoxia by using post-stimulus time and single-pass time histograms. Of eighteen cardiac related cells recorded from the RVLM area, twelve cells were excited by iontophoresed sodium cyanide and of twenty-five respiration related cells, fourteen cells were excited by iontophoresed sodium cyanide. Remaining cells were either inhibited or unaffected. Eight of fifteen cells tested with iontophoresed sodium lactate were excited and remaining seven cells were inhibited. Systemic hypoxia induced by nitrogen gas inhalation elevated the arterial blood pressure, but excited, inhibited or unaffected the single neuronal activities. Some cells showed initial excitation followed by inhibition during the systemic hypoxia. Bilateral vagotomy resulted in a decrease of arterial pressor response to the systemic hypoxia, and a slight decrease in the rhythmicity related to cardiac and/or respiratory rhythms. The single neuronal responses to either systemic or focal hypoxia were not affected qualitatively by vagotomy. From the above results, it was concluded that the majority of the cardiac- and respiration- related neurons in the rostral ventrolateral medulla be excited by hypoxia, not through the mediation of peripheral chemoreceptors, and along with the remaining inhibited cells, all these cells be involved in the mediation of cerebral ischemic reflex.

• Journal of Life Science
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• v.18 no.11
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• pp.1493-1498
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• 2008

We defined factors affecting the postoperative outcome in adult cardiac surgery with cardiopulmonary bypass (CPB). Thirty-two adult patients scheduled for elective cardiac surgery participated in this study. Levels of leukocyte, glutamic oxaloacetic transaminase (GOT), troponin-I (cTNI), interleukin-6 (IL-6), D-dimer and neuron-specific enolase (NSE) were significantly elevated, whereas platelet count declined in cardiac surgery with CPB. GOT and D-dimer levels at CPB-off each had a positive significant correlation significantly with 24 hrs-bleeding, total bleeding, mechanical ventilatory assist time, ICU stay time and length of hospitalization. BUN levels at CPB-off were directly related to total bleeding, mechanical ventilatory assist time, ICU stay time and length of hospitalization. Platelet count at CPB-off was inversely related to mechanical ventilatory assist time, ICU stay time and length of hospitalization. Creatinine concentration at CPB-off interrelated positively with mechanical ventilatory assist time and ICU stay time. NSE levels at CPB-off had a positive relationship with postoperative 24 hrs-bleeding. The length of hospitalization was prolonged proportionally to the elevation of cTNI levels in cardiac surgery. Aortic cross-clamping and total CPB times also related with increase of 24 hrs and total bleeding volumes and the length of hospitalization. IL-6 and ET-1 had no mutual relation with any postoperative outcome. These data suggest that GOT, BUN, creatinine, D-dimer and platelet levels are the most important factors affecting postoperative outcomes and patient's recovery in adult cardiac surgery with CPB.

• Journal of Korean Critical Care Nursing
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• v.16 no.3
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• pp.99-108
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• 2023

Purpose : This retrospective study aims to provide basic data for intervention to improve clinical outcomes and identify the characteristics of the rebound hyperthermia (RHG) and non-rebound hyperthermia (NRHG) groups by checking body temperature in patients with post-cardiac arrest syndrome. Method : The study involved 118 patients who completed target temperature management (TTM) in an acute-care unit. Data were analyzed for frequency, percentages, mean, standard deviation, median, and quartiles, and compared using the chi-squared test and Mann-Whitney U-test. Results : Rebound hyperthermia (RH) was observed in 74 (62.7%) patients, predominantly male (69.5%), with an average age of 64.54 ± 15.98, and a body mass index of 23.22 ± 4.75kg/m² (overweight). Hypertension (50%) was the most common co-morbidity, followed by diabetes and heart disease (33.1%). Neuron-specific enolase levels were higher in the NRHG 24, 48, and 72 hours after recovery of spontaneous circulation (p = .037, p < .001, p = .008). The APHCHE IV was also higher in the NRHG (p < .001). RH occurred 25.49 (7.28-52.96) hours after TTM completion, lasting for 2 (1-3) hours. Temperature reduction strategies included notifying doctors, administering antipyretics, and nursing intervention, with the latter being the most common at 94.6%. Half of the subjects in the RHG and 77.3% in the NRHG fell into cerebral performance categories 3, 4, and 5 (p = .003). Conclusion : RH is more likely a body mechanism related to CPR and TTM than a result of pathogenic infection. Therefore, we require an active intervention for hyperthermia, and a patient-specific nursing intervention protocol.

• Journal of Chest Surgery
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• v.31 no.5
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• pp.441-450
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• 1998

The medullospinal tract cells are known to play an important role in the control of the cardiovascular activities. To clarify the modes of action of the neurotransmitters on these cells, glutamate, GABA(${\gamma}$-aminobutyric acid) and bicuculline were applicated iontophoretically into the rostral ventrolateral medulla in adult cats anesthetised with ${\alpha}$-chloralose. Followings are the results obtained : 1. The spontaneous activities of the cardiac-related neurons in rostral ventrolateral medulla (RVLM) were increased by the glutamate and decreased by the GABA. 2. Bicuculline, an antagonist of GABA, alone didn't increase the frequency of the action potentials, but could reverse the cellular response to the GABA, simultaneously applicated. 3. GABA seemed to decrease the peak as well as the basal discharge of the neurons in RVLM, but hardly changed their periodicities. 4. The cellular responses of RVLM evoked by the peripheral nerve stimulation could be inhibited by the iontophoretically released GABA. In conclusion, GABA seemed to act as an inhibitory neurotransmitter on the cardiac- related neurons in RVLM of the cats anesthetized with ${\alpha}$-chloralose. But the maintenance of the periodicities of these cells after the application of bicuculline suggested that the afferent activity of the baroreceptor didn't play a key role in the spontaneous activities of the RVLM neurons.