Sung-Moon Jeong

Laboratory Variables Associated with Low Near-Infrared Cerebral Oxygen Saturation in Icteric Patients Before Liver Transplantation Surgery

BACKGROUND: Although regional cerebral oxygen saturation (rSO2) measurements can detect disturbances in cerebral oxygenation, their usefulness is limited in patients with hyperbilirubinemia. We examined the relationship between rSO2 and other laboratory variables that may affect interpretation of low rSO2 in awake patients with end-stage liver disease before liver transplantation surgery. METHODS: Before induction of general anesthesia, rSO2 was measured in 164 patients with liver cirrhosis (Child class A/B/C = 19/41/104) and 8 with fulminant hepatic failure. Patients with West Haven hepatic encephalopathy of grade 3 or 4 were excluded. Relationships between rSO2 and laboratory variables were evaluated by correlation and multivariate regression, and by receiver operating characteristic curve analysis. RESULTS: Univariate analyses showed that rSO2 (median 58.5%, range 15% to 82%) correlated with serum total bilirubin, hemoglobin (Hb), creatinine, sodium, and magnesium concentrations, and prothrombin time (P < 0.001 each), but not with serum concentrations of glucose, albumin, potassium, and ammonia. Multiple logistic regression analysis showed that only elevated total bilirubin (range 0.4 to 66 mg/dL; odds ratio [OR] = 1.31; 95% confidence interval [CI] = 1.18 to 1.45) and low Hb (range 5.3 to 15.7 g/dL; OR = 0.21; 95% CI = 0.11 to 0.43) were independently related to rSO2 <50%. The optimum cutoff points for observing an rSO2 <50% were total bilirubin >7.2 mg/dL (sensitivity 89%, specificity 90%) and Hb <9.6 g/dL (sensitivity 70%, specificity 82%). CONCLUSIONS: High total bilirubin and low Hb concentrations were independently associated with rSO2 values below 50% in end-stage liver disease patients awaiting liver transplantation. The results of this study identify patients in whom a low rSO2 may be an artifact rather than cerebral ischemia.

The Effects of Dantrolene on Hypoxic-Ischemic Injury in the Neonatal Rat Brain

BACKGROUND:The pathophysiology of brain damage from hypoxia or ischemia has been ascribed to various mechanisms and cascades. Intracellular calcium overload and a calcium excitotoxic cascade have been implicated. It has been suggested that disturbances of endoplasmic reticulum calcium homeostasis are involved in the induction of neuronal cell injury. Two types of intracellular Ca2+-release channels, involving the ryanodyne receptor and the inositol (1,4,5)-triphosphate receptor, are essential for Ca2+ signaling in cells. Dantrolene, which is used for the treatment of malignant hyperthermia syndrome, has been reported to inhibit Ca2+ release through ryanodyne receptors from the endoplasmic reticulum into the cytosol. We designed this study to investigate the neuroprotective effects of dantrolene on hypoxic-ischemic brain damage in the neonatal rat brain. METHODS:Seven-day-old Sprague-Dawley rats were assigned into two groups; control group (n = 69) and dantrolene group (n = 60). Dimethyl sulfoxide was administered intracerebroventricularly in the control group, and dantrolene in dimethyl sulfoxide was similarly administered to the dantrolene group, before hypoxic-ischemic brain injury (HII). HII was induced by the ligation of the common carotid artery under isoflurane anesthesia, followed by exposure to about 2.5 h of hypoxia (oxygen concentration was maintained at 7%-8%). 1H magnetic resonance spectroscopy was performed 1 day after HII. This noninvasive method evaluated apoptotic processes in the brain after HII. Morphologic score analyses and the calculated percentage of infarct areas after 2,3,5-triphenyltetrazolium chloride staining 14 days after HII were also used to evaluate the effects of dantrolene on HII. Terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling (TUNEL) staining was performed 1 day after HII using 24 more rats. RESULTS:The lipid/creatine ratios in the right hemispheres in the dantrolene group 1 day after HII were significantly lower than those of the control group (P < 0.05). There was no significant difference between the two groups in the N-acetylaspartate/creatine ratios. The gross morphologic scores were lower in the dantrolene group than in the control group (P < 0.05), and infarct area (%) after 2,3,5-triphenyltetrazolium chloride staining was less in the dantrolene group than in the control group (P < 0.05) 14 days after HII. Further work with 24 rats showed no significant difference, however, in the number of TUNEL positive cells on the two groups. CONCLUSIONS:Our results show that dantrolene, administered intracerebroventricularly before HII, had a neuroprotective effect in HII model of the neonatal rat brain.

Warming of Intravenous Fluids Prevents Hypothermia During Off-Pump Coronary Artery Bypass Graft Surgery

OBJECTIVE Even mild perioperative hypothermia (34 degrees -36 degrees C) can cause numerous adverse outcomes, including morbid cardiac events, coagulopathy with increased blood loss, and a decreased resistance to surgical wound infection. The purpose of this study was to evaluate the effect of fluid warming on preventing hypothermia during off-pump coronary artery bypass (OPCAB) surgery. DESIGN A prospective randomized clinical study. SETTING A tertiary care university hospital. PARTICIPANTS Forty patients undergoing OPCAB procedures. INTERVENTIONS Patients were randomized into control (n = 20) and Hotline (n = 20) groups. In the Hotline group, all intravenous fluids were warmed to 41 degrees C by using 2 Hotline (SIMS Inc, Rockland, MD) systems. All patients (control and Hotline groups) were managed with standardized institutional practice by using a combination of increased ambient operating room temperature (to 25 degrees C) and the use of a warmed water mattress (38 degrees C). MEASUREMENTS AND MAIN RESULTS Temperatures were recorded every hour after the induction of anesthesia at the pulmonary artery, nasopharynx, rectum, and bladder. In the Hotline group, temperatures were maintained or increased. In the control group, temperatures gradually decreased. There were no significant differences between the 2 groups in hemodynamic parameters, serum catecholamine concentrations, duration of intensive care unit stay, or duration of ward stay. CONCLUSIONS The results show that the warming of intravenous fluids by using the Hotline system prevents decreases in systemic temperatures during OPCAB surgery.

Continuous peritransplant assessment of consciousness using bispectral index monitoring for patients with fulminant hepatic failure undergoing urgent liver transplantation

Hwang S, Lee SG, Park JI, Song GW, Ryu JH, Jung DH, Hwang GS, Jeong SM, Song JG, Hong SK, Lim YS, Kim KM. Continuous peritransplant assessment of consciousness using bispectral index monitoring for patients with fulminant hepatic failure undergoing urgent liver transplantation.
Clin Transplant 2010: 24: 91–97.

Similar neuroprotective effects of ischemic and hypoxic preconditioning on hypoxia-ischemia in the neonatal rat: a proton MRS study.

The aim of this study was to evaluate the effect of ischemic and hypoxic preconditioning on hypoxia–ischemia (HI) in the neonatal rat. Seven‐day‐old Sprague‐Dawley rats were divided into four groups: control, sham, ischemic preconditioning, and hypoxic preconditioning. Ischemic preconditioning with a 10‐min occlusion of the right carotid artery and hypoxic preconditioning with 4‐h of hypoxia (8% oxygen) were performed 24‐h before HI. For HI, all rats underwent right carotid artery ligature, followed by 2.5‐h of hypoxia. Proton magnetic resonance spectroscopy (1H MRS) and TUNEL staining were evaluated at 1 and 7 days after HI. At 2 weeks after HI, all rats were sacrificed for morphological analysis. The lipid (Lip), N‐acetyl aspartate (NAA), creatine (Cr), and choline‐ratios were calculated and compared with TUNEL staining and brain morphologies. Both the ischemic and hypoxic preconditioning groups showed lower Lip/NAA and Lip/Cr ratios and morphological scores, and fewer TUNEL‐positive cells than the control and sham groups (P < 0.05). There were no significant differences between the two preconditioning groups. In addition, the ratios correlated with the TUNEL staining and the degrees of morphological changes in all of the groups (P < 0.05). These results suggest that ischemic and hypoxic preconditioning in neonatal rats with HI similarly attenuate brain injury. Moreover, Lip/NAA and Lip/Cr ratios may be used as markers for assessing the extent of brain damage.

The changes of skin temperature on hands and feet during and after T3 sympathicotomy for palmar hyperhidrosis.

Unilateral thoracic sympathectomy in patients with palmar hyperhidrosis causes a skin temperature drop in the contralateral hand. A cross-inhibitory effect by the post-ganglionic neurons innervating hands is postulated as a mechanism of contralateral vasoconstriction. The purpose of our study was to evaluate whether this cross-inhibitory effect also occurs in the feet. Twenty patients scheduled for thoracoscopic sympathicotomy due to palmar hyperhidosis were studied. Right T3 sympathicotomy was performed first, followed by left T3 sympathicotomy. The thenar skin temperatures of both hands and feet were continuously monitored using a thermometer and recorded before induction of anesthesia, during the operation, 4 hr after and 1 week later. Following right T3 sympathicotomy, the skin temperature of the ipsilateral hand gradually increased, however the skin temperature of the contralateral hand gradually decreased. Immediately after bilateral sympathicotomy, the skin temperature differences between hands and feet increased, but these differences decreased 1 week later. Our results show that cross-inhibitory control may exist in feet as well as in the contralateral hand. Thus, the release of cross-inhibitory control following T3 sympathicotomy results in vasoconstriction and decrease of skin temperature on the contralateral hand and feet. One week later, however, the temperature balance on hands and feet recovers.

Clinical survey of sedation and analgesia procedures in intensive care units

BACKGROUND The proper use of sedation and analgesia in the intensive care unit (ICU) minimizes its physical and psychological impact. Otherwise, patients can suffer from recall, nightmares, and depression after discharge. We investigated the sedatives, analgesics, and muscle relaxants used in the ICU. METHODS We visited 79 ICUs in 52 training hospitals and noted the use of sedatives, analgesics, and muscle relaxants from July, 2007, to December, 2007, using a 5-item questionnaire with 57 sub-questions. The survey evaluated the ICU system administration of analgesics and muscle relaxants. RESULTS Most ICU management is done by the anesthesiology department (55%). Most have resident doctors (63.3%) and an ICU committee (60.8%) in charge of the ICU, as well as a special ICU chart (88.6%) and scoring system (65.8%). Most hospitals have a consulting system (94.9%). The standard ICU analgesics are fentanyl (65.8%), NSAIDs (53.2%), and morphine (48.1%). CONCLUSIONS Adequate sedation is difficult to achieve in the ICU, but is important for patient comfort and to reduce ICU stay duration. Awareness of patient status and appropriate drug/protocol use are therefore important.