Preliminary development and evaluation of the support system for care of mechanically ventilated patients.

BACKGROUND: We wanted to demonstrate the feasibility of a novel computer-assisted ventilator alarm system, the support system for care of mechanically ventilated patients (SCMVP), to detect gas leaks and provide graphical information on the site of the leak in a manikin model. METHODS: We tested six leakage scenarios. Four scenarios were applied to both the respiratory circuits with the SCMVP and without the SCMVP (conventional system), and two scenarios were each specific to one of the systems. Fifteen registered nurses were asked to manage three scenarios each (two mutual and one system-specific scenario). Time to identify the site of the leak was measured and compared between the two systems. RESULTS: The SCMVP showed significantly shorter time for troubleshooting in one of the four mutual scenarios and shorter accumulated time for troubleshooting in the four mutual scenarios [18.0 (range, 14.5-19.5) and 48.5 (9.0-180.0) s, respectively] compared with the conventional system [76.0 (47.0-133.8) and 82.5 (16.0-180.0) s, respectively]. In the mutual scenarios, SCMVP resulted in significantly more frequent incidences of successful troubleshooting within 30 s and less frequent incidences of troubleshooting requiring >180 s [43.3% (13/30) and 6.7% (2/30), respectively] compared with the conventional system [13.3% (4/30) and 30% (9/30), respectively]. CONCLUSIONS: The SCMVP can facilitate rapid and successful recognition of the site of leak in a respiratory circuit in a simulation environment.

Synergistic effect of cold and warm ischemia time on postoperative graft function and outcome in human liver transplantation.

Prolonged cold ischemia time (CIT) during graft preservation and warm ischemia time (WIT) during rewarming time have been reported to cause postoperative graft dysfunction after orthotopic liver transplantation (OLT). However, the effects of both CIT and WIT in combination on patient and graft survivals are not yet defined. The aim of this study was to determine whether simultaneously prolonged CIT and WIT were associated with early graft outcomes after clinical OLT. For analysis of liver graft survival within 90 days of OLT and postoperative graft function, 186 consecutive OLT cases were divided into four groups as follows: group A, CIT < 12 hours and WIT < 45 minutes; group B, CIT > 12 hours and WIT < 45 minutes; group C, CIT < 12 hours and WIT > 45 minutes; and group D, CIT > 12 hours and WIT > 45 minutes. The graft loss rates were 5.4% in group A, 9.8% in group B, 11.1% in group C, and 42.9% in group D. The mean highest aspartate aminotransferase (AST) value after OLT in group D (3352.3 +/- 569.4 U/L) was significantly greater than those in groups A (1411.7 +/- 169.2 U/L) and B (1931.3 +/- 362.6 U/L). The simultaneously prolonged cold and warm ischemia times significantly caused hepatic allograft injury and failure, suggesting some cumulative effects of CIT and WIT on postoperative graft function.

Analysis of clinical variables of donors and recipients with respect to short-term graft outcome in human liver transplantation.

UNLABELLED: Donor and recipient factors are closely associated with graft survival after orthotopic liver transplantation (OLT). This study was performed to analyze clinical characteristics of recipients and donors, which affect 30-day graft loss after OLT. MATERIALS AND METHODS: One hundred eighty-six livers from heart-beating donors were accepted between May 1997 and June 1998 at the University of Pittsburgh Medical Center. Donor variables that were analyzed included age, sex, cold ischemia time (CIT), warm ischemia time (WIT), imported versus local procurement, cardiopulmonary arrest, serum sodium level, and dopamine dose. The recipient characteristics included native liver disease and UNOS status. Two-sided Fisher exact test and stepwise logistic regression were used for univariate and multivariate analyses. P-values < .05 were considered statistically significant. RESULTS: Twenty-eight grafts (15.1%) were lost within 30 days of OLT. The following factors were found to adversely affect graft survival: donor sodium > 155 mEq/L (P = .002); CIT > 12 hours (P = .002); WIT > 45 minutes (P = .002); and imported liver graft (P = .048). Logistic regression revealed that donor sodium (odds ratio, 3.03; 95% CI, 1.05 to 8.74), CIT (OR 1.20; 95% CI 1.05 to 1.38), WIT (OR 1.06; 95% CI 1.01 to 1.09) were independent predictors of early graft loss. CONCLUSION: Donor hypernatremia as well as warm and cold ischemia times independently affect graft outcomes in the early postoperative period after OLT. Avoidance of long preservation and correction of donor sodium level are recommended to optimize results and survival in OLT.

Preparation of a new thermo-responsive adsorbent with maltose as a ligand and its application to affinity precipitation.

A thermo-responsive polymer on which maltose was covalently immobilized as an affinity ligand was newly synthesized for purification of thermolabile proteins from the crude solution by affinity precipitation. Among the thermo-responsive polymers synthesized as carriers for adsorbent, poly(N-acryloylpiperidine)-cysteamine (pAP) has a lower critical solution temperature (LCST) of around 4 degrees C, at which its solubility exhibits a sharp change. Adsorbent for affinity precipitation was prepared by combining pAP with maltose using trimethylamine-borane as a reducing reagent. This adsorbent (pAPM) obtained showed a good solubility response: pAPM in the basal buffer (pH 7.0) became soluble below 4 degrees C and was completely insoluble above 8 degrees C. The affinity precipitation method using pAPM consisted of the following four steps: adsorption at 4 degrees C, precipitation of the complex at 10 degrees C, desorption by adding the desorption reagent at 4 degrees C, and recovery of a target protein at 10 degrees C. In the affinity precipitation of Con A from the crude extract of jack bean meal, 82% of Con A added was recovered with 80% purity by addition of 0.2 M methyl-alpha-D-mannopyranoside as a desorption reagent. In the repeated purification of Con A from the crude extract, pAPM could be satisfactorily reused without decrease in the affinity performance. Moreover, when pAPM was used for the purification of thermolabile alpha-glucosidase from the cell-free extract of Saccharomyces cerevisiae, 68% of total activity added was recovered and the specific activity per amount of protein of the purified solution was enhanced 206-fold higher than that of the cell-free extract without thermal deactivation of the enzyme.

[Crossed "cerebral" diaschisis? Seven cases with unilateral cerebellar vascular lesion which showed decreased perfusion in the contralateral cerebral cortex].

In 7 cases with unilateral cerebellar vascular lesion, decreased perfusion was observed in the contralateral cerebral cortex by single photon emission computed tomography (SPECT) with I-123 labeled N-isopropyl-p-iodoamphetamine (IMP). These cases had symptoms due to cerebellar lesions but did not show any cerebral cortical symptoms. Reduction of cerebral cortical perfusion appeared on more than 25 days after the onset of CVA, did not correlate with morphological changes by cranial X-ray computed tomography and digital subtraction angiography in acute phase, and was persistent or irreversible later. We made a guess this phenomenon was due to the remote neuronal effect through cerebellothalamic projection.