Arginine-vasopressin attenuates beneficial norepinephrine effect on jejunal mucosal tissue oxygenation during endotoxinaemia.

BACKGROUND: The objective of the present study was to investigate the effects of increasing doses of norepinephrine (NE) with or without arginine-vasopressin (AVP) on intestinal oxygen supply and jejunal mucosal tissue oxygen tension in an acute endotoxic pig model. METHODS: In this prospective, randomized, experimental study on 24 domestic pigs, jejunal mucosal tissue PO2 (PO2muc) was measured using two Clark-type surface oxygen electrodes. Oxygen saturation of jejunal microvascular haemoglobin (HbO2j) was determined by tissue reflectance spectrophotometry. Systemic haemodynamic variables, mesenteric-venous and systemic acid-base and blood gas variables, and lactate measurements were recorded. Measurements were performed at baseline, after Escherichia coli lipopolysaccharide (LPS) administration, and at 20 min intervals during incremental NE infusion (0.05, 0.1, 0.5, 1.0, and 2 microg kg(-1) min(-1), respectively) with 57 mU kg(-1) h(-1) AVP (n=8; NE+AVP group) or without (n=8; NE group); or infusion of an equal amount of normal saline (n=8; CON group). RESULTS: LPS infusion led to a significant (P<0.05) decrease of PO2muc and HbO2j. Both NE and NE+AVP increased arterial pressure, cardiac output, and mesenteric artery blood flow. Concomitant to an increase in systemic oxygen delivery, NE improved PO2muc and HbO2j. NE alone was superior in restoration of PO2muc when compared with NE+AVP. CONCLUSIONS: Both NE and NE+AVP improved global haemodynamics and systemic oxygen transport variables when compared with control animals in an acute endotoxic pig model. NE improved jejunal PO2muc at all dosages. NE effects were significantly blunted by simultaneous administration of AVP.

[Streptococcus suis meningitis and neurophysiology of the acoustic system. First case report from Austria]. / Streptococcus-suis-Meningitis und Neurophysiologie des akustischen Systems. Erster Fallbericht aus Osterreich.

Meningitis caused by Streptococcus suis was diagnosed in a 63 year old female in Austria. Sixteen months after onset she still suffers from ataxia, disturbance of gait and bilateral hearing impairment. Being a farmer, the patient belongs to a recognized high-risk-group, as most other infected people do. To the best of our knowledge, there has been no report of a human infection by Streptococcus suis in Austria so far. The results of neurophysiological tests excluded a direct lesion to the cochlea during the acute phase of meningitis, and thus, are in contrast to the guinea-pig-model by Kay, who showed suppurative labyrinthitis being the cause of hearing loss. The present knowledge of Streptococcus suis meningitis with respect to neurophysiology, pathogenesis, epidemiology and increasing resistance against antibiotics is discussed.

Inotropic treatment and intestinal mucosal tissue oxygenation in a model of porcine endotoxemia.

OBJECTIVE: To evaluate the dose-related effects of dopamine, dopexamine, and dobutamine on intestinal mucosal tissue oxygenation following short-time infusion of Escherichia coli lipopolysaccharide, which has previously been shown to decrease mucosal tissue oxygenation by 60% of control values. DESIGN: Prospective, randomized, unblinded study. SETTING: Animal research laboratory. SUBJECTS: Anesthetized, mechanically ventilated domestic pigs. INTERVENTIONS: Pigs were infused with 2 microg/kg of E. coli lipopolysaccharide over 20 mins via the superior mesenteric artery. Pulmonary artery occlusion pressure was maintained near 15 mm Hg, using a mixed infusion regimen of Ringer's lactate solution and hydroxyethyl starch. Following endotoxemia, a small segment of the jejunal mucosa was exposed by midline laparotomy and antimesenteric incision. The control group (n = 7) received no further interventions. Pigs in the dopamine (n = 7), dopexamine (n = 7), and dobutamine (n = 7) groups were infused with 2.5, 5, 10, and 20 microg/kg/min of the respective drug via a central venous catheter. MEASUREMENTS AND MAIN RESULTS: Systemic hemodynamics as well as systemic, mesenteric, and femoral blood gas variables were measured using an arterial, a thermodilution pulmonary artery, a superior mesenteric venous, and a femoral venous catheter. Jejunal mucosal tissue PO2 was measured by means of two Clark-type surface oxygen electrodes. Oxygen saturation of jejunal mucosal microvascular hemoglobin was determined by tissue reflectance spectrophotometry. Infusion of endotoxin resulted in pulmonary hypertension. Systemic hemodynamics remained unchanged except for brief decreases in cardiac output and arterial blood pressure. Dopamine, dopexamine, and dobutamine increased systemic oxygen delivery in a dose-related manner by 80% (p < .01), 96% (p = .00), and 129% (p = .00) of values before inotropic treatment. Dopamine increased mucosal tissue PO2 by 109% (10-microg dose, p < .01) and 164% (20-microg dose, p = .00), and mucosal hemoglobin oxygen saturation by 61% (5-microg dose, p < .05), 102% (10-microg dose, p < 01) and 121% (20-microg dose, p = .00). Dopexamine increased mucosal tissue PO2 by 89% (20-microg dose, p < .01) and mucosal hemoglobin oxygen saturation by 26% (2.5-microg dose, p < .05) and 35% (5-, 10-, and 20-microg dose, p < .05). In the dobutamine and control groups, no significant effect on either mucosal tissue PO2 or hemoglobin oxygen saturation was observed. CONCLUSIONS: In this model of porcine endotoxemia, dopamine and, to a lesser extent, dopexamine increase intestinal mucosal tissue oxygenation. Of all three inotropes used, dobutamine has the most pronounced effect on systemic oxygen delivery, but it does not improve mucosal tissue oxygenation. Selective vasodilation within the intestinal mucosa, mediated mainly by dopamine-1 receptors, seems to explain the observed intestinal mucosal effect of dopamine and dopexamine.

Flexor tenosynovitis in the hand caused by Mycobacterium malmoense: a case report.

This report analyzes a rare case of flexor tenosynovitis caused by Mycobacterium malmoense. A synovectomy was carried out on the index finger (no other finger was afflicted) of a 66-year-old farmer, followed by antibiotic therapy with ethambutol, rifampin, and clarithromycin. Because of strong side effects, the treatment with ethambutol and rifampicin had to be discontinued after 4 months. There was no recurrence after 14 months, and the patient's finger had a full range of motion.

Effects of short-term endotoxemia and dopamine on mucosal oxygenation in porcine jejunum.

Effects of Escherichia coli lipopolysaccharide (2 micrograms.kg-1.20 min-1; LPS), given systemically (S) or via superior mesenteric artery (M), and consecutive dopamine infusion (16 micrograms.kg-1.20 min-1) on jejunal mucosal tissue O2 tension (PO2muc) and serosal tissue O2 tension (PO2ser; Clark-type surface electrodes) and jejunal mucosal microvascular hemoglobin O2 saturation (HbO2muc; tissue reflectance spectrophotometry) were investigated in a hemodynamically stable pig model. Twenty-one pigs were anesthetized, paralyzed, and mechanically ventilated. After laparotomy, a mesenteric venous catheter was inserted and a jejunal antimesenteric enterotomy performed. LPS-infused animals developed similar degrees of pulmonary hypertension. No differences in cardiac output and mean arterial blood pressure between groups were found. PO2muc and HbO2muc were significantly lower in M animals compared with control (C) [210 min; PO2muc: 7.12 +/- 1.81 (M), 19.01 +/- 3.12 mmHg (C); HbO2muc: 28.78 +/- 3.36 (M), 49.09 +/- 3.84% (C)], whereas S animals ranged in between (PO2muc: 13.36 +/- 2.2 mmHg; HbO2muc: 40.68 +/- 4.43%). Of measured PO2muc values, 12.6 (C), 20.6 (S), and 46.3% (M) ranged from 0 to 5 mmHg. PO2ser was lower in LPS animals compared with control [59.43 +/- 5.4 (C), 45.00 +/- 6.12 (S), 47.33 +/- 4.34 (M) mmHg]. Dopamine increased PO2muc and HbO2muc to similar absolute values and significantly decreased frequency of PO2muc (0-5 mmHg) in M animals. We conclude that LPS impairs mucosal tissue oxygenation independently of systemic hemodynamics. Mucosal microvascular dysfunction depends on regional LPS concentrations. Under conditions of compromised tissue oxygenation, dopamine significantly improves PO2muc and HbO2muc.