Ketamine does not affect intestinal microcirculation in pentobarbital-anaesthetized rats during experimental endotoxaemia.

The objective of the study was to evaluate the effects of ketamine on intestinal microcirculation in pentobarbital-anaesthetized rats during experimental endotoxaemia. A prospective, randomized, controlled study was carried out using 32 male Lewis rats. The animals were divided into four groups (n = 8 each). All animals were initially anaesthetized with 60 mg/kg pentobarbital (i.p.). Group 1 served as a control (18.5 mg/kg/h pentobarbital i.v.). Groups 2 and 4 received an endotoxin intravenous infusion of 15 mg/kg lipopolysaccharide (LPS) from Escherichia coli. Groups 3 and 4 also received 10 mg/kg/h ketamine (i.v.). After 2 h of observation, the animals were examined for intestinal functional capillary density (FCD) and leukocyte adherence to the venular endothelium by means of intravital fluorescence microscopy (IVM). Subsequent to this examination, blood samples were collected to determine release of the cytokines tumour necrosis factor (TNF)-alpha, interleukin (IL)-1beta, IL-6 and IL-10. Endotoxaemia tended to decrease intestinal FCD (mucosa: -10.1%, muscularis longitudinalis: -2%, muscularis circularis: -9.8%) and significantly increase leukocyte adherence within submucosal venules (collecting venules: +133%, postcapillary venules: +207%; P<0.05). TNF-alpha, IL-1beta, IL-6 and IL-10 levels were significantly elevated following endotoxin challenge. The addition of ketamine to pentobarbital anaesthesia did not significantly affect FCD, leukocyte behaviour or cytokine levels. In conclusion, intravenous pentobarbital anaesthesia with the additional administration of ketamine did not cause alterations within the microcirculation or changes in cytokine release during endotoxaemia. In rats, the combination of pentobarbital and ketamine is suitable for use during the study of intestinal microcirculation in experimental endotoxaemia.

Metronidazole improves intestinal microcirculation in septic rats independently of bacterial burden.

To explore the effects of metronidazole (Me) on intestinal microcirculation in septic rats, intravital microscopy (IVM) following 16 hours of colon ascendens stent peritonitis (CASP model) was used. Four groups of animals were studied: control group (sham operation) and CASP group, each with and without Me treatment (10 mg/kg i.v.). In order to investigate the substance-specific effects of Me independently of the antibacterial effects within a pathologically altered microcirculation, a second experimental series with lipopolysaccharide challenge (LPS model) was carried out. The LPS model consisted of the four groups (control animals and LPS animals (15 mg/kg i.v. LPS from E. coli) with and without Me). IVM in the LPS experiments was performed following a two hour observation period. Me treated CASP or LPS animals, as compared with untreated, demonstrated significant improvement of functional capillary density (FCD) of the intestinal wall. The increase in the number of leukocytes firmly adhered to the endothelium (leukocyte sticking) in the untreated CASP or LPS animals within the V1 venules of the intestinal submucosal layer, was significantly reduced in the Me treated animals. In conclusion, Me exerts beneficial anti-bacterial and anti-inflammatory effects within the septic microcirculation.

[PercuTwist dilational tracheostomy. Prospective evaluation of 54 consecutive patients]. / PercuTwist-Dilatationstracheotomie. Prospektive Evaluation an 54 konsekutiven Patienten.

BACKGROUND: Percutaneous dilational tracheostomy (PDT) is considered to be an accepted method in intensive care patients. In 2002 Frova and Quintel described a method of dilation that employed controlled rotation of the PercuTwist dilational device. The goal of the present study was to evaluate the new technique employed by an experienced team. PATIENTS AND METHODS: Prospective, observational clinical study in 54 intensive care patients who required PDT. All tracheostomies were accompanied by bronchoscopic control. Vital parameters and perioperative complications were registered. RESULTS: In all 54 consecutive PercuTwist tracheostomies no severe complications were noted. Accidental tracheal ring fracture was noted in 7 patients while bleeding that needed surgical care occurred in 1 patient. CONCLUSION: The PercuTwist tracheostomy is a safe procedure for intensive care patients. More prospective studies that would compare the PercuTwist tracheostomy with the other PDT methods are necessary.

[Acute traumatic myocardial infarction with cardiogenic shock in severe polytrauma--a case report]. / Akuter traumatischer Myokardinfarkt mit kardiogenem Schock bei schwerem Polytrauma--ein Fallbericht.

A 41-year-old man suffered severe polytrauma and developed a traumatic myocardial infarction with cardiogenic shock. Thrombolysis as well as coronary bypass grafting was contraindicated due to accompanying injuries. An attempted early coronary revascularization by percutaneous transluminal coronary angioplasty (PTCA) failed due to dissection of the left interventricular coronary artery. Treatment of cardiac insufficiency was complicated by intraabdominal haemorrhage enforcing emergency laparotomy. Intraaortic balloon counterpulsation proved to be efficient in supporting circulation in these circumstances. The case report documents the practicability and importance of treating both myocardial ischaemia and attending injuries in an equivalent and coordinated manner in traumatic myocardial infarction.

[Ventilation-perfusion distribution with volume-reduced, pressure-limited ventilation with permissive hypercapnia]. / Ventilations-Perfusions-Verteilung unter volumenreduzierter drucklimitierter Beatmung mit permissiver Hyperkapnie.

PURPOSE: Low volume pressure-limited ventilation with permissive hypercapnia (PH) may decrease the mechanical stress of the lung in acute respiratory insufficiency. Alveolar PCO2 is a determinant of regional ventilation, whereas increased mixed-venous and arterial PCO2 may affect systemic and pulmonary haemodynamics. The aim of this study was to analyse the ventilation-perfusion (VA/Q) distribution during controlled ventilation with permissive hypercapnia. METHODS: The study was approved by the ethical committee of the Ernst-Moritz-Arndt University of Greifswald. Eleven patients with severe ARDS (lung injury severity score 2.77 +/- 0.47) were studied. Intrapulmonary shunt (QS/QT, % of QT), lung areas with 0.005 < or = VA/Q < or = 0.1 ("low" VA/Q, % of QT), lung areas with 10 < or = VA/Q < or = 100 ("high" VA/Q, % of VE), dead space ventilation (VD/VT = VA/Q > 100, % of VE) and the mean distribution of ventilation (Vmean VA/Q) and perfusion (Qmean VA/Q) were determined by the multiple inert gas elimination technique during normocapnic (NC) and hypercapnic (HC) mechanical ventilation. In addition, systemic mean arterial and pulmonary arterial pressure, cardiac output (CO) and arterial and mixed venous partial pressures for oxygen (PaO2, PvO2) and carbondioxide (PaCO2, PvCO2) were assessed. RESULTS: Low-volume pressure-limited ventilation was associated with moderate hypercapnia (PaCO2 = 61 +/- 12 mmHg vs. 39 +/- 6 mmHg, p < 0.01). QS/QT increased (28 +/- 16% [NC] vs. 36 +/- 17% [HC], p < 0.05), whereas Qmean VA/Q decreased from 1.01 +/- 0.37 (NC) to 0.65 +/- 0.49 (HC), (p < 0.01) and Vmean VA/Q decreased from 1.54 +/- 0.58 (NC) to 1.12 +/- 0.93 (HC) (p < 0.05). Hypercapnia induced mild systemic hypotension and pulmonary hypertension. CO increased from 10.8 +/- 2.3 l/min to 11.6 +/- 2.6 l/min (p < 0.05). PaO2 was almost unchanged, but PvO2 increased significantly from 40 +/- 4 mmHg (NC) to 49 +/- 7 mmHg (HC) (p < 0.01). CONCLUSION: The mechanical ventilation with permissive hypercapnia may increase shunt due to alveolar derecruitement and an impaired hypoxic pulmonary vasoconstriction. PaO2 was unchanged due to an increased CO, PvO2 and--to a lesser extent--shift of the oxyhaemoglobin dissociation curve.

[Application of the laryngeal mask for elective percutaneous dilatation tracheotomy]. / Anwendung der Larynxmaske für die elektive perkutane Dilatationstracheotomie.

Percutaneous dilatational tracheostomy is an increasingly accepted procedure for bed-side tracheostomy. The exact positioning of the endotracheal tube, the localization of the point for puncturing the trachea and damage to the endotracheal tube and the cuff as well as to the bronchoscope due to the puncturing process are technical problems which can endanger the course of the operation. In a prospective randomized study, we examined whether use of the laryngeal mask airway (LMA) is a real alternative to the endotracheal tube during tracheostomy. Of 48 consecutive patients only 43 fulfilled all criteria for this study: PaO2 > 100 mmHg, PaCO2 < 45 mmHg (in patients with head injury < 35 mmHg) under intermittent positive pressure ventilation (IPPV) with a mean ventilation pressure of < 25 mmHg and an FiO2 of 1.0. Patients with intestinal obstruction, hemorrhages of the mouth and nose and unfavourable anatomic conditions were not included in this study. Three more patients had to be excluded from the study because of technical problems. In 21 patients tracheostomy was performed using an endotracheal tube (ET group) and in 19 patients using a LMA (LM group). After positioning of the endotracheal tube or the LMA, tracheostomy was performed in the usual way. Arterial blood gases (PaO2 and PaCO2) were investigated before positioning of the endotracheal tube or the LMA, five minutes after this procedure and five minutes after the end of tracheostomy. Mean arterial pressure (MAP), heart frequency (HF) and peripheral oxygen saturation (SpO2), endexpiratory CO2 partial pressure (PetCO2) and minute ventilation volume (MVV) were registered every 60 seconds. The ET group and LM group did not differ regarding basic diseases, age and severity of illness. Before the beginning of tracheostomy, there were no differences in MAP, HF, SpO2, PetCO2 and PaCO2 between the two groups. Before tracheostomy, only PaO2 was significantly higher in the LM group than in the ET group. Immediately before the insertion of the tracheal cannula and five minutes after the end of tracheostomy, there were no differences in the measured parameters of the two groups. An increase in PetCO2 and a decrease in minute ventilation volume were observed in both groups. Regarding technical complications, the LMA is a safe alternative to the endotracheal tube. The choice of method should depend on the basic disease and the patient's ventilation requirements at the time of tracheostomy, while there is still a call for safe instruments guaranteeing sufficient sealing of the respiratory tract during the dilatational tracheostomy and simultaneous avoidance of technical problems during puncturing of the trachea and widening of the point of puncturing.

[Local oxygen supply to the cerebral cortex during thiopental and propofol anesthesia. First results]. / Lokale Sauerstoffversorgung des zerebralen Kortex während Thiopental-und Propofolanästhesie. Erste Ergebnisse.

Because the brain is highly vulnerable to damage from even a brief imbalance of oxygen delivery and demand, intraoperative disturbances of local oxygen supply must be avoided. Until now, there has been no method allowing fast and reliable intraoperative measurement of the local oxygen supply in the human brain. Intraoperative investigations were therefore performed using the Erlangen micro-lightguide spectrophotometer. METHODS. Intraoperative investigations of local intracapillary haemoglobin saturation (SO2) were performed during neurosurgical interventions using the Erlangen microlightguide spectrophotometer (EM-PHO). Measurements were performed in eight patients (age 31-67 years) during neurosurgical interventions. Three received thiopentone anaesthesia, and three received propofol. In two patients thiopentone anaesthesia was later changed to propofol. The EMPHO enables rapid, non-invasive measurement of local intracapillary SO2. White light from a Xenon-arc lamp is transmitted by a 250-microns micro-lightguide to the tissue. The remitted (reflected) light is led by 6 micro-lightguides surrounding the illuminating one to a rotating band-pass interference filter disk. Light in the range of 502 to 630 nm is detected with a photomultiplier. In this range haemoglobin shows an SO2-dependent spectrum, which is then analysed. Because the measurements are performed with micro-lightguides, high spatial resolution is attained. Representative measurements can be performed in a very short period of time (approx. 60 s); thus, the EM-PHO enables rapid monitoring of local SO2 in the brain. RESULTS. The effect of propofol and thiopentone anaesthesia on the distribution of local intracapillary haemoglobin saturation was investigated during neurosurgical interventions. The arterial PCO2 was similar in both groups (31 +/- 0.7 and 31 +/- 0.5 mmHg, respectively). There were also no differences in arterial blood pressure. The FiO2 was 0.28 +/- 0.04 in the thiopentone group and 0.30 +/- 0.1 in the propofol group. In all patients receiving propofol anaesthesia higher local SO2 values were found, even if the patients first received thiopentone (values in parenthesis). The mean local SO2 amounted to 65.4% (57.3%) in the propofol group and 38.8% (45.2%) in the thiopentone group. The number of values below 25% SO2 was 5.6% (5.8%) in the propofol group and 18.7% (19.1%) in the thiopentone group.

[Anesthesiological risks in neurologic diseases]. / Anästhesiologische Risiken bei neurologischen Erkrankungen.

For an exact evaluation of the risks of operations it is necessary to assess both co-existing and concomitant diseases before the performance of anaesthesia. The relatively low incidence of neurological and muscular diseases (0.02 to 0.7/1,000) and the low probability of an operation of a patient suffering from these diseases lead to higher anaesthesiological risks during the operation and the perioperative period. The anaesthetist is usually not always aware of all the special pathophysiological problems which have to be taken into consideration when these patients have to be anaesthetized. In order to reduce the risk of anaesthesia of these patients, we discuss the most important of these uncommon neurological diseases regarding their special anaesthesiological management.

[Selective gut decontamination in ventilated intensive therapy patients]. / Selektive Darmdekontamination bei beatmeten Intensivtherapiepatienten.

Treatment of long-term artificially ventilated patients is often complicated by nosocomial infections. The infection that occurs with the highest frequency during intensive care treatment is pneumonia (22-63%). Ninety per cent of nosocomial infections of intensive care patients are endogenous infections caused by mainly gram-negative aerobic microorganisms that have colonized in the gastrointestinal tract. Selective decontamination of the intestine provides a method that prevents nosocomial infections. In a prospective study 13 patients whose oropharynx and gastrointestinal tract had been decontaminated (SDD) were compared to 17 patients in a control group. In a third group twelve patients were decontaminated in the gastrointestinal tract (SGD) only, and in a fourth group 16 patients were decontaminated in the oropharynx (SMD) only. Trachea, oropharynx and faeces of the patients belonging to the control group (KG) were colonized to almost 100% with gram-negative bacteria. Only 10% of the patients of the SDD and SMD groups showed gram-negative bacteria located in the trachea and oropharynx after one week of decontamination. No gram-negative aerobic bacteria were present after seven days in the faeces of the patients of the SDD and SGD groups. There was no difference with regard to the trachea and oropharynx between the control group and the SGD group. The gram-negative aerobic intestinal flora was not affected by the selective mouth decontamination. The average rate of pneumonia occurrence within the 15-day observation period was 28.2% for the control group, 14% for the SGD group, and 9.6% for the SDD group, and 4.1% for the SMD group. Decontamination of the oropharynx of patients is essential in order to successfully prevent pneumonia.(ABSTRACT TRUNCATED AT 250 WORDS)

[The HELLP syndrome--3 case reports with clinically different course]. / Das HELLP-Syndrom--3 Kasuistiken mit klinisch unterschiedlichen Verläufen.

Three case reports of patients with HELLP-syndrome show how different the clinical courses in HELLP-syndrome may be. A maternal case of death after eclampsia and HELLP-syndrome explains that early diagnosis and immediate therapy are important for success in the treatment of HELLP-syndrome. After delivery--at present the only efficient causal therapy (we recommend a quick cesarean section after making the diagnosis)--an increase of the number of thrombocytes and a normalization of the liver enzymes can be observed within a few days. An intensive co-operation of obstetricians, anesthetists, and pediatricians in the treatment of patients with HELLP-syndrome is necessary.

[Behavior of thrombocytes in low-dose heparin therapy]. / Verhalten der Thrombozyten unter low dose-Heparintherapie.

In a little prospective study it could be shown that a series of 10-51 low dose heparin injections may be followed by slight or unspecific thrombocyte diminutions without specific heparin antibodies being available. Depending on stress and trauma potential complement activations caused by heparin histon complexes may result in insignificant thrombocyte diminutions by liberating those factors activating platelets from granulocytes. These are not bound to interrupt heparin therapy or heparin prophylaxis.