Electro-acupuncture Stimulation at Acupoints Reduced the Severity of Hypotension During Anesthesia in Patients Undergoing Liver Transplantation

Background: Patients with end-stage liver diseases who undergo liver transplantation may suffer from hypotension related to the liver disease itself or related to the surgical procedure. Because electro-acupuncture (EA) at the Neiguan (PC-6) and the Jianshi (PC-5) points influences hemodynamics, we hypothesize that electro-acupuncture at the traditionally used acupuncture points will reduce the severity of hypotension in patients who undergo liver transplantation. Methods: Forty patients with end-stage liver disease who underwent orthotropic deceased donor liver transplantation were randomized into two groups. The norepinephrine (NE) group received norepinephrine as a vasoconstrictor, and the electro-acupuncture group received EA at the PC-5 and the PC-6 points for treatment of hypotension during anesthesia for the liver transplantation. The patients were monitored, during the three stages of liver transplantation by using hemodynamic parameters. Results: During the three stages of liver transplantation, there were no significant differences in the hemodynamic measurements including the mean arterial pressure, heart rate and central venous pressure between the two groups (p > 0.05). Conclusions: Electro-acupuncture at the acupuncture points reduced the severity and the incidence of hypotension during anesthesia for liver transplantation

Preclustering Algorithms for Imprecise Points

We study the problem of preclustering a set B of imprecise points in Rd: we wish to cluster the regions specifying the potential locations of the points such that, no matter where the points are located within their regions, the resulting clustering approximates the optimal clustering for those locations. We consider k-center, k-median, and k-means clustering, and obtain the following results. Let B: = { b1, … , bn} be a collection of disjoint balls in Rd, where each ball bi specifies the possible locations of an input point pi. A partition C of B into subsets is called an (f(k) , α) -preclustering (with respect to the specific k-clustering variant under consideration) if (i) C consists of f(k) preclusters, and (ii) for any realization P of the points pi inside their respective balls, the cost of the clustering on P induced by C is at most α times the cost of an optimal k-clustering on P. We call f(k) the size of the preclustering and we call α its approximation ratio. We prove that, even in R1, one may need at least 3 k- 3 preclusters to obtain a bounded approximation ratio—this holds for the k-center, the k-median, and the k-means problem—and we present a (3k, 1) preclustering for the k-center problem in R1. We also present various preclusterings for balls in Rd with d⩾ 2 , including a (3 k, α) -preclustering with α≈ 13.9 for the k-center and the k-median problem, and α≈ 193.9 for the k-means problem

The Effect of Intraoperative Restricted Normal Saline during Orthotopic Liver Transplantation on Amount of Administered Sodium Bicarbonate

Background: Severe metabolic acidosis occurs during orthotopic liver transplantation (OLT) particularly during the anhepatic phase. Although NaHCO3 is considered as the current standard therapy, there are numerous adverse effects. The aim of this study was to determine whether the restricted use of normal saline during anesthesia could reduce the need for NaHCO3. Methods: In this study we enrolled 75 patients with end-stage liver disease who underwent OLT from February 2010 until September 2010 at the Shiraz Organ Transplantation Center. Fluid management of two different transplant anesthetics were compared. The effect of restricted normal saline fluid was compared with non-restricted normal saline fluid on hemodynamic and acid-base parameters at three times during OLT: after the skin incision (T1), 15 min before reperfusion (T2), and 5 min after reperfusion (T3). Results: There were no significant differences in demographic characteristics of the donors and recipients (P>0.05). In the restricted normal saline group there was significantly lower central venous pressure (CVP) than in the non-restricted normal saline group (P=0.002). No significant differences were noted in the other hemodynamic parameters between the two groups (P>0.05). In the non-restricted normal saline group arterial blood pH (P=0.01) and HCO3 (P=0.0001) were significantly less than the restricted normal saline group. The NaHCO3 requirement before reperfusion was significantly more than with the restricted normal saline group (P=0.001). Conclusion: Restricted normal saline administration during OLT reduced the severity of metabolic acidosis and the need for NaHCO3 during the anhepatic phase. Trial Registration Number: IRCT2013110711662N