The effect of skin surface warming during anesthesia preparation on preventing redistribution hypothermia in the early operative period of off-pump coronary artery bypass surgery.

OBJECTIVE: Redistribution hypothermia adversely affects hemodynamics and postoperative recovery in patients undergoing cardiac surgery. In off-pump coronary bypass surgery (OPCAB), maintaining the temperature is important because warming by cardiopulmonary bypass is omitted. Pre-warming studies reported earlier showing pre-warming as an effective means of preventing redistribution hypothermia was time consuming since it required at least 1-2h to pre-warm the patients before the surgery. Because pre-warming for such a long time is impractical in clinical practice, this study evaluated the efficacy of active warming during the preanesthetic period for the prevention of redistribution hypothermia in the early operative period of OPCAB. METHODS: After gaining the approval of Institutional Review Board and informed consent from the patients, 40 patients undergoing OPCAB were divided into control and pre-warming groups. The patients in control group (n=20) were managed with warm mattresses and cotton blankets, whereas patients in pre-warming group (n=20) were actively warmed with a forced-air warming device before the induction of anesthesia. Hemodynamic variables and temperature were recorded before anesthesia (Tpre) and at 30 min intervals after anesthesia for 90 min (T30, T60, and T90). RESULTS: Active warming duration was 49.7+/-9.9 min. There were no statistically significant differences in skin temperature, core temperature and hemodynamic variables between the two groups at preinduction period except for mean arterial pressure and central venous pressure. The core temperature at T30, T60, and T90 was statistically higher in pre-warming group than that in control group. Core temperature of six (30%) and seven patients (35%) in control group was reduced below 35 degrees C at T60 and T90, respectively, whereas core temperature of only one patient (5%) in pre-warming group was reduced below 35 degrees C at T90 (P=0.02). CONCLUSIONS: Active warming using forced air blanket before the induction of anesthesia reduced the incidence and degree of redistribution hypothermia in patients undergoing OPCAB. It is a simple method with reasonable cost, which does not delay the induction of anesthesia nor the surgery.     

Future direction of nanomedicine in gastrointestinal cancer]

Cancer is one of the leading causes of death in human, and among various cancers, gastrointestinal cancers occupy more than 55%. Gastric cancer is the first leading cause of cancer-related mortality in the world and the number of pancreas and colon cancers are increasing remarkably during last two decades which will continue to increase in the future. Even though the clinical importance of gastrointestinal cancers is very high and endless efforts has been made to develop novel diagnostic and therapeutic methods to improve the patient's quality of life and survival, the realistic advance in the actual survival benefit of the cancer patients are still strongly required. Nanotechnology has the power to radically change the way of cancer diagnosis and treatment. Currently, there is a lot of researches on novel nanodevices capable of detecting cancer at its earliest stage, pinpointing its location within the body, and delivering anticancer drugs specifically to the malignant cells. Nanoscale devices can readily interact with biomolecules both on the cell surface and within the cell. In addition, nanoscale devices are already proven that they can deliver therapeutic agents to target cells even within specific organelles. Major areas in which nanomedicine is being developed in cancer include early detection and proteomics, imaging diagnostics and multifunctional therapeutics. Because nanotechnology would provide a technical power and tool that enable new diagnostics, therapeutics, and preventives to keep pace with today's explosion in knowledge in the future, it would be very useful to know the perspectives in the direction of nanotechnology as a major clinician responsible for the patients with gastrointestinal malignancies.     

Particle size and morphology of UHMWPE wear debris in failed total knee arthroplasties--a comparison between mobile bearing and fixed bearing knees.

Osteolysis induced by ultrahigh molecular weight polyethylene wear debris has been recognized as the major cause of long-term failure in total joint arthroplasties. In a previous study, the prevalence of intraoperatively identified osteolysis during primary revision surgery was much higher in mobile bearing knee replacements (47%) than in fixed bearing knee replacements (13%). We postulated that mobile bearing knee implants tend to produce smaller sized particles. In our current study, we compared the particle size and morphology of polyethylene wear debris between failed mobile bearing and fixed bearing knees. Tissue specimens from interfacial and lytic regions were extracted during revision surgery of 10 mobile bearing knees (all of the low contact stress (LCS) design) and 17 fixed bearing knees (10 of the porous-coated anatomic (PCA) and 7 of the Miller/Galante design). Polyethylene particles were isolated from the tissue specimens and examined using both scanning electron microscopy and light-scattering analyses. The LCS mobile bearing knees produced smaller particulate debris (mean equivalent spherical diameter: 0.58 microm in LCS, 1.17 microm in PCA and 5.23 microm in M/G) and more granular debris (mean value: 93% in LCS, 77% in PCA and 15% in M/G).     

Effect of a low-protein diet on doxorubicin pharmacokinetics in the rabbit

Summary Malnutrition involving protein deficiency, which commonly occurs in cancer patients receiving anthracycline treatment, is considered to be a risk factor for the development of cardiotoxicity. Protein deficiency has been shown to impair the metabolism of drugs such as theophylline and acetaminophen. If protein deficiency also impairs anthracycline metabolism, it could explain at least in part the enchanced anthracycline toxicity associated with malnutrition. We tested this idea by determining the effect of a low- protein, isocaloric diet on doxorubicin pharmacokinetics in rabbits. The animals were randomized into two groups for 8–12 weeks. Rabbits in group 1 received a low-protein (5%), isocaloric diet, whereas those in group 2 received a normal-protein (15%) diet. Both groups (group 1,n=15; group 2,n=14) were given 5 mg/kg doxorubicin by i.v. bolus. After doxorubicin injection, blood samples were obtained over the next 52 h for the measurement of doxorubicin and doxorubicinol plasma concentrations by high-performance liquid chromatography (HPLC) with fluorometric detection. The low-protein diet significantly decreased doxorubicin clearance (48±3 vs 59±4 ml min^–1 kg^–1;P<0.05), prolonged the terminal climination half-life (28±2 vs 22±2 h;P<0.05), and increased the area under the plasma concentration/time curve extrapolated to infinity (1722±122 vs 1405±71 ng h ml^–1;P<0.05) as compared with the values determined for rabbits fed the standard rabbit chow (15% protein). The volume of distribution for doxorubicin was not altered by the low-protein diet. In addition, in rabbits fed the the low-portein diet, the terminal elimination half-life of the alcohol metabolite, doxorubicinol was prolonged (52±5 vs 40±2 h;P<0.05). Thus, a low-protein diet causes a reduction in the ability of rabbits to eliminate doxorubicin and possibly its alcohol metabolite doxorubicinol. If a similar alteration in anthracycline pharmacokinetics occurs in malnourished cancer patients, this phenomenon may contribute to their increased risk of developing cardiotoxicity associated with anthracycline therapy.Supported by the Department of Veterans Affairs and the American Heart Foundation