Search

The objective of the present study was to investigate sublingual microvascular blood flow and microcirculatory haemoglobin oxygen saturation (Smc(O(2))) during cardiopulmonary bypass (CPB) using constant systemic blood flow but different perfusion pressures achieved by phenylephrine administration.Fifteen patients undergoing coronary artery bypass grafting were enrolled in this pilot study. Systemic haemodynamics, oxygen transport variables, arterial and mixed venous blood gas analysis, and microcirculatory variables were determined after initiation of general anaesthesia, during CPB (systemic blood flow=2.4 litre m(-2)), after increasing perfusion pressure by 20 mm Hg with a continuous infusion of phenylephrine, and after termination of phenylephrine infusion.CPB immediately resulted in a significant (P0.05) decrease in systemic oxygen transport without alterations in sublingual microcirculatory blood flow and Smc(O(2)). Increasing perfusion pressure from 47 (SD 9) to 68 (7) mm Hg using phenylephrine=1.4 (1.0) microg kg(-1) min(-1) resulted in a significant decrease in sublingual small vessel blood flow (from median 2.5 to 1.8 arbitrary units) representing mostly capillary blood flow, but not in medium-sized vessels (median 3 to 2.8 arbitrary units). Concurrently, global tissue blood flow from 110 (54) to 197 (100) perfusion units and Smc(O(2)) increased from 72 (11)% to 84 (7)%, suggesting significant microcirculatory blood flow shunting in vessels with diameters25 microm.Our data demonstrate that an increased perfusion pressure produced by phenylephrine at constant CPB flow may decrease microcirculatory blood flow in the sublingual mucosal microcirculation due to microvascular blood flow shunting.

Highly Substituted Cyclopentadienes with Arylthio and Arylsulfonyl Groups Cyclopentadienes 1 react with diaryl disulfides 2 to form the tetrakis(arylthio)cyclopentadienides 3, which have been oxidized with m-chloroperbenzoic acid to give the tetrakis(arylsulfonyl)cyclopentadienides 5. Protonation of 5 yields the tetrakis(arylsulfonyl)cyclopentadienes 7 by migration of arylsulfonyl groups. Oxidation of 3 by iodine leads to the dihydropentafulvalenes 11. By reaction of 3 with arylthiosulfonates 14 the pentakis(arylthio)cyclopentadienes 15 have been obtained. Their salts 16 may be oxidized to form the pentakis(arylsulfonyl)cyclopentadienides 17, or condensed with sulfenyl chlorides to give the hexakis(arylthio)cyclopentadienes 19. The structure of the phenylthio compound 19a was confirmed by an X-ray structure analysis.

The use of venoarterial extracorporal membrane oxygenation and ventricular assist-devices in children with end stage heart failure is well established. The use of a bridge-to-bridge strategy leads to excellent survival rates in pediatric patients. We present an adolescent, who acquired acute respiratory failure, due to possible transfusion related lung injury, and who was successfully treated with venovenous extracorporal membrane oxygenation while on ventricular assist-device support.

During hypothermic cardiopulmonary resuscitation with a body core temperature30 degrees C administration of a vasopressor to support coronary perfusion pressure is controversial. The purpose of the current study was to assess the effects of a single 0.4-unit/kg dose of vasopressin on coronary perfusion pressure, defibrillation success, and 1-hr survival in a pig model of hypothermic closed-chest cardiopulmonary resuscitation combined with rewarming.Prospective, randomized study in an established pig model.University hospital research laboratory.Fifteen 12- to 16-wk-old domestic pigs.Pigs were surface cooled to a body core temperature of 26 degrees C and ventricular fibrillation was induced. After 15 mins of untreated cardiac arrest, manual closed-chest cardiopulmonary resuscitation and thoracic lavage with 40 degrees C warmed tap water were started. After 3 mins of external chest compression, animals were assigned randomly to receive vasopressin (0.4 units/kg, n = 8; or saline placebo, n = 7). Defibrillation was attempted 10 mins after drug administration.Compared with saline placebo treated-animals, coronary perfusion pressure in vasopressin-treated pigs was significantly higher 90 secs (36 +/- 5 mm Hg vs. 7 +/- 4 mm Hg, p =.000) to 10 mins (24 +/- 4 mm Hg vs. 8 +/- 4 mm Hg, p =.000) after drug administration. Restoration of spontaneous circulation and 1 hr survival were significantly higher in vasopressin animals compared with saline placebo (8 of 8 vasopressin pigs vs. 0 of 7 placebo pigs, p.001).A single 0.4-unit/kg dose of vasopressin administered at a body core temperature30 degrees C significantly improved defibrillation success and 1-hr survival in a pig model of hypothermic cardiopulmonary resuscitation.

OBJECTIVE: Vasopressin is a possible stimulus for both adrenocorticotropin (ACTH) and endothelin-1 release. The aim of this study was to compare plasma concentrations of ACTH, cortisol, and endothelin-1 after epinephrine or vasopressin administration in an experimental animal model of cardiopulmonary resuscitation (CPR). DESIGN: Prospective, randomized, controlled animal study. SETTING: A university research laboratory. SUBJECTS: Fourteen 12- to 14-wk-old domestic pigs. INTERVENTIONS: After 4 mins of cardiac arrest and 3 mins of external chest compression, the pigs were randomly assigned to receive either 0.045 mg/kg epinephrine (n = 7) or 0.4 units/kg vasopressin (n = 7). At 5 mins after drug administration, defibrillation was attempted. MEASUREMENTS AND MAIN RESULTS: Coronary perfusion pressure, ACTH, cortisol, and endothelin-1 were measured before cardiocirculatory arrest, during CPR before drug administration, and at 90 secs and 5 mins after drug administration. Coronary perfusion pressure was comparable between groups. All seven animals in the vasopressin group survived, but only one pig in the epinephrine group survived (p = .005). ACTH and cortisol concentrations remained unchanged in epinephrine-treated animals, but increased significantly after vasopressin administration and were significantly higher than in epinephrine-treated animals 5 mins after drug administration. Endothelin-1 concentrations remained unchanged during the study period and were comparable between both groups. CONCLUSIONS: Vasopressin is a potent stimulus for ACTH secretion, but does not trigger endothelin-1 release from vascular cells during cardiac arrest and CPR. The increased plasma cortisol concentrations caused by the enhanced ACTH release after vasopressin may be one factor contributing to the improved outcome repeatedly observed with vasopressin in animal models of CPR.

Cardiopulmonary bypass (CPB) has been associated with intestinal tissue hypoxia, but direct measurements of mucosal oxygenation have not been performed. In anaesthetized pigs, jejunal mucosal oxygen tension and microvascular haemoglobin oxygen saturation were measured by a Clark-type electrode and tissue reflectance spectrophotometry. In pigs, normothermic CPB with systemic oxygen transport equivalent to baseline values was performed. In control animals, mucosal oxygen tension and mucosal haemoglobin oxygen saturation were mean 5.01 (SD 1.08) kPa and 38.0 (2.3)%, respectively. CPB was associated with a decrease in mucosal oxygen tension to 2.26 (1.21) kPa, decrease in mucosal microvascular haemoglobin oxygen saturation to 26.0 (3.9)% and appearance of oscillations in mucosal microvascular haemoglobin oxygen saturation. With CPB, arterial lactate concentrations increased from 1.77 (1.37) to 3.52 (1.58) mmol litre-1, but transvisceral lactate and splanchnic venous-arterial carbon dioxide tension gradients remained unchanged. Our results support the concept that CPB is associated with diminished oxygenation of intestinal mucosa that is probably caused by regional redistribution.

Case Presentation A poorly equipped 54-year-old man without climbing experience crossed a heavily crevassed glacier in the Austrian Alps. After a few minutes walk, he fell into a narrow crevasse about 4 meters deep. A rescue team was immediately summoned and arrived about 50 minutes later. The victim in the crevasse was conscious when the rescue team arrived but had slipped farther down the crevasse, by melting the ice around him with his body temperature. In the following hour, several efforts to reach the victim and to tie a rope around his body failed because the crevasse was too narrow. Meanwhile, the victim in the crevasse had become unresponsive, and occasional sighing remained the only visible sign of life. Finally, a very small member of the rescue team managed to fix a rope around the man, and the victim was removed from the crevasse within a few minutes. Rough handling of the patient during rescue and postural changes could not be totally avoided. Meanwhile, an emergency physician had arrived by helicopter. He immediately evaluated the patient removed from the crevasse. The patient was in deep coma, had no spontaneous breathing, no palpable pulses, and fixed, dilated, pupils. Electrocardiogram (ECG) demonstrated ventricular fibrillation. The patient was endotracheally intubated, artificially ventilated, and external chest compression was started. Tympanic temperature was measured and demonstrated severe accidental hypothermia with a body core temperature of 23°C. Therefore, the emergency physician decided to transport the patient immediately to this center by helicopter for rewarming with extracorporeal circulation (ECC). No medication was given on the scene or during air transport, and there were no attempts at defibrillation at the scene. After a 20-minute flight with ongoing cardiopulmonary

The genome of the murine Coronavirus MHV-JHM is a positive-stranded RNA of approximately 30 Kb, which encodes 4 structural proteins (N, M, S and HE) and at least 4 non-structural proteins. The location of the major open reading frames (ORFs) in the genome is shown in Fig. 1. In the infected cell, expression of the viral proteins is mediated by a set of subgenomic mRNAs. In relation to the genome the mRNAs are 3′ coterminal and extend to different positions in a 5′ direction. The mRNAs 7, 6, 3 and 2-1 have been shown to encode the N, M, S and HE proteins respectively (Siddell, 1983; Pfleiderer et al., this volume). mRNA 4 encodes a 15,000 molecular weight (mol.wt.) non-structural protein (Ebner et al, 1988) and mRNA 5 has the potential to encode two non-structural proteins of 12,400 and 10,200 mol.wt. (Skinner et al., 1985). Earlier in vitro translation studies (Siddell, 1983), indicated that the MHV-JHM subgenomic mRNA 2 encodes a 30,000 mol.wt. nonstructural protein, the expression of which was translationally regulated. Recent sequence analysis of the 5′ proximal region of the closely related MHV-A5 9 mRNA 2 confirms the presence of a 261 aminoacid ORF at this position. Analysis of the predicted polypeptide sequence indicates a non-membrane protein which may possibly have nucleotide binding and phosphorylating properties (Luytjes et al., 1988).

A simulation model was developed to describe the degree of primary care coverage focussing on the aspect of supply (providers) and demand (consumers) of a health care delivery system. It describes variables influencing supply and demand and reflects the relationships between these parts. The model determines the degree of primary care coverage for a region and prognosticates trends within a region. The model was tested on four different regions: a metropolitan area, a suburban area, a smal1 city and a rural area.

Information mediation and the functions of intermediaries from the subjective viewpoint of information specialists were subject of an inquiry concerning biomedical information services and its communication network DIMDINET. This paper primarily focusses on a few major aspects: profile of requirements of qualification and education of information specialists, organization structure and problems of centralization and decentralization of information centers, the role of commercial information brokers, the end-user as searcher. The inquiry was based on the Delphi technique.