A comparison of perioperative factors with two methods of coronary artery bypass grafting (CABG): off-pump and conventional

BACKGROUND: The safety and efficiency of off-pump coronary artery bypass grafting (OPCAB) are still controversial. The purpose of this study was to evaluate this approach in comparison with the conventional cardiopulmonary bypass technique (cCABG). METHODS: A retrospective review of patients who had undergone coronary artery bypass grafting independently without other operations between January 1, 1999 and September 30, 2001 was performed. The patients were divided into two groups: those who underwent OPCAB and the remainder for cCABG. The perioperative factors of the two groups were compared. RESULTS: A total of 152 OPCAB and 142 cCABG cases were reviewed. Compared with cCABG, OPCAB significantly reduced the amount of catecholamine needed on admission to ICU, intubation time, overall hospital length of stay, and neurologic events. There were also trends for decreases in ICU length of stay, mortality, and renal failure. On the other hand, OPCAB did not affect perioperative blood loss. CONCLUSIONS: Overall OPCAB is safer and more efficient than cCABG. However, we have to note in anesthetic management that OPCAB does not reduce blood loss.     

Glucose attenuating local anesthetic-induced hemolysis

BACKGROUND: The effect of glucose on local anesthetic-induced neural damage has not been fully studied. We examined the effect of glucose on hemolysis induced by local anesthetics. METHODS: The mean EC50 values (the local anesthetic level that causes destruction of half of the red blood cells in vitro) of lidocaine HCl, tetracaine HCl and dibucaine HCl were determined with 0% and 7.5% glucose contained in Krebs solution at pH 6.4. RESULTS: The mean EC50 values of lidocaine HCl, tetracaine HCl, and dibucaine HCl in 0%-glucose Krebs solution were 6.51%, 0.45%, 0.17%, respectively, which increased significantly to 7.05%, 0.64% and 0.23%, in 7.5% glucose Krebs solution at pH 6.4. CONCLUSIONS: Glucose may have a protective role in local anesthetic-induced neural damage.     

Evaluation of creatine kinase level during long-term tocolysis

OBJECTIVE: This study was performed to evaluate serum creatine kinase (CK) levels during tocolytic therapy. METHODS: A retrospective study was performed in 27 patients who were treated with intravenous tocolytic agents for more than one week. The first-line tocolytic agent was ritodrine hydrochloride, followed by concomitant magnesium sulfate (MgSO4). The serum CK level was measured on admission and every week thereafter. The patients were divided into the normal CK (group 1) and abnormal CK (> 150 IU/L) (group 2) groups. RESULTS: Seventeen patients received both ritodrine hydrochloride and MgSO4. The CK levels in all patients rose significantly from 58.4 +/- 30.8 IU/L on admission to 116.0 +/- 68.7 IU/L on day 7 (p = 0.002). Abnormal elevation of CK occurred in 7 (25.9%) of the 27 patients. Significant differences were found between groups 1 and 2 in the total doses of ritodrine and MgSO4 (p = 0.046 and p = 0.0028, respectively). All patients in group 2 received ritodrine in combination with MgSO4 (p = 0.018). CONCLUSION: When tocolytic therapy continued for more than 1 week, nearly one-fourth of patients showed an increase in CK level above the normal range.     

Image analysis of remesothelialization following chemical wounding of cultured human peritoneal mesothelial cells: the role of hyaluronan synthesis

BACKGROUND: To understand what happens during the wound healing process of the mesothelium, we have developed an in vitro wounding model of cultured human peritoneal mesothelial cells (HPMCs) utilizing an image acquisition and analysis system. Using this system, cell mobility and hyaluronan synthesis were quantified and their interrelationship discussed. METHODS: 1N NaOH was used to create circular wounds in cultured HPMC monolayers, which were then exposed for 30 minutes to the peritoneal dialysis solutions or fetal calf serum (FCS)-free M199 culture medium, followed by incubation with 0.3% FCS/M199 culture medium for up to 96 hours. Digitalized microscopic date was captured every 30 minutes to quantify the wound healing process. In separate experiments, the HPMC monolayers were stained with biotin-conjugated hyaluronan-binding protein (B-HABP) at a regular time interval. RESULTS: Centripetal migration of the HPMCs into the wound area was the predominant process involved in wound repair with proliferation playing a secondary role. Two noticeable observations were made from the digital video movies: (1) cell mobility varied and was dependent upon the morphology and location of the cell relative to the wound edge, and (2) cell migration continued even after wound closure. Staining for B-HABP was confined to the remesothelialized area when wound closure was complete at 24 hours. At 48 hours after wound closure, the stained area was even more visible, although somewhat diffuse; thereafter, staining was reduced to almost background levels. CONCLUSION: The cell culture model of wound healing used in our study has enabled us to demonstrate quantitative image data of the cellular processes that occur during wound healing. We have been able to continuously observe cell migration, proliferation, and transformation. Synthesis and subsequent decomposition of hyaluronan appears to be related to the mobility of the wounded and intact HPMCs in this model system.     

Ionic strength influences hemolytic action of dibucaine hydrochloride

BACKGROUND: Little is known about effect of ionic strength on local anesthetic toxicity. Using human erythrocytes, hemolytic action of dibucaine in solutions of various ionic strength was investigated. METHODS: The critical micellar concentration (CMC) of dibucaine and the dibucaine level that causes destruction of half of the red blood cells in vitro (EC50 value) were determined in solutions of various ionic strength. RESULTS: The mean CMC values of the dibucaine solutions adjusted to ionic strength 0.15, 0.30, 0.45 and 0.90 with NaCl, were 35.3, 22.6, 15.9 and 9.6 mM, respectively. The mean EC50 values of these solutions measured at 5 sec were 22.5, 16.0, 12.6 and 8.2 mM, respectively, and those at 30 min were 4.9, 4.5, 4.5 and 2.6 mM, respectively. There was a significant correlation between mean CMC values and mean EC50 values at 5 sec but not at 30 min in the solution of the same ionic strength. CONCLUSIONS: These findings indicated that the mechanism of dibucaine-induced hemolysis within a few seconds is through membrane lysis, whereas dibucaine-induced hemolysis at 30 min is caused by another mechanism. Because each mechanism is enhanced by high ionic strength, dibucaine dissolved in salt solution should not be administered intrathecally.     

Primary malignant melanoma arising from the base of the tongue

A rare case of malignant melanoma of the base of the tongue in a 65-year-old Japanese woman is described. The primary and metastatic tumors were treated by surgery, chemohormone and immunotherapy. There was no recurrence for 5 years after the initial diagnosis. Electron microscopy suggested that the melanosomes of the melanoma cells in the cervical lymph nodes were less mature than those in the primary melanoma cells; melanosome immaturity was consistent with a more aggressive quality.