Competence for transcranial color-coded Duplex sonography is rapidly acquired.

BACKGROUND: Transcranial color-coded Duplex sonography (TCCD) is a non-invasive bedside tool with broad diagnostic potential in the intensive care setting. Implementation of TCCD requires repeated reliable measurements of flow velocities despite data acquisition by multiple operators with varying experience. Thus the learning curve of TCCD and agreement of measurements between experienced and inexperienced operators is of great interest and unstudied so far. METHODS: Six untrained ICU-residents and 2 trained operators participated and performed TCCD examinations of the mean cerebral artery (MCA) in 10 volunteers. Measurements of the residents were compared to the according measurements of the trained operators. Operators were either actively supervised during their first five examinations or performed the examinations without supervision. RESULTS: A total of 480 measurements were obtained. Mean flow velocity (MFV) did not differ significantly between trained and untrained operators in the two groups (P=0.78 in not-supervised and P=0.82 in supervised group). We found a favorable learning curve in both groups (ICC 0.8, CI 95% 0.6-0.91- in not supervised and ICC 0.81 CI 95% 0.63-0.92 in supervised group). However, supervision helped trainees to acquire skills more rapidly and to perform more accurate measurements (ICC 0.77 (95% CI 0.39-0.94) to ICC 0.91 (95% CI 0.77-0.98) and ICC 0.66 (95% CI 0.11-0.91) to ICC 0.84 (95% CI 0.58-0.96), respectively. CONCLUSION: TCCD of the MCA in volunteers is an easy to learn tool with a favorable learning curve. A short-term learning program including initial supervised measurements yields reliable results in the hands of inexperienced operators.

Consequences of one-lung flooding: a histological and immunological investigation.

BACKGROUND: Videothoracoscopic lung sonography after partial fluid instillation could be a new method for endoscopic detection of lung lesions. Histopathological consequences of unilateral diagnostic or therapeutic lung flooding under bronchoalveolar lavage has yet to be defined. The aim of the study was to investigate histological and immunohistological alterations induced by one-lung flooding (OLF). METHODS: 13 female pigs were subjected to OLF (15 ml isotonic electrolyte solution per kg for 60 minutes), and lung tissue was collected 30 minutes, 2 hours, 24 hours, 48 hours, 6 days, 8 days, and 10 weeks after flooding. Histological examinations and immunohistochemical labeling for surfactant protein A (SP-A) were performed. Cellular proliferation was measured by Ki67 immunohistochemical labeling. Apoptosis was detected through enzymatic in-situ labeling of apoptosis-induced DNA strand breaks by means of the TUNEL (TdT-mediated dUTP nick end labeling) method. RESULTS: Histological analyses revealed the presence of inflammatory cell infiltrates in the interstitium at 24 hours after OLF. However, no destruction of the alveolar wall and no pulmonary oedema were observed. In addition, OLF was not associated with any decrease in surfactant protein A immunoreactivity. Two hours after OLF, the number of apoptotic cells was increased (OLF: 7% vs. CONTROL: 0.6%, p < 0.05), but cellular proliferation was unchanged. Conversely, at 48 h after OLF, the number of apoptotic cells had returned to control levels, but cellular proliferation had increased (OLF: 5% vs. CONTROL: 1.1%, p < 0.05). Cellular proliferation returned to baseline levels eight days after OLF. CONCLUSIONS: These data demonstrate that OLF is not associated with destruction of the alveolar texture, atelectasis-provoking surfactant loss, or any irreversible damage to the pulmonary parenchyma. Lung flooding for the purpose of videothoracoscopic lung sonography is safe and justifiable. But repeated lung flooding under bronchoalveolar lavage involving the same lung area within 1 week is not to be recommended.

[Covering defects of the basal finger area by pedicled flaps anastomosed to the doral metacarpal arteries]. / Deckung von Defekten an den Fingergrundgliedern durch distal an den dorsalen Metakarpalarterien gestielte Lappen.

Between 1993 and 1998, 12 distally based dorsal metacarpal artery flaps were used to cover defects of the fingers and palm. All flaps were raised from the dorsum of the hand. Eleven flaps allowed direct closure of the donor site area; one case required a full-thickness skin graft. Nine flaps healed uneventfully. Distal marginal flap necrosis occurred in three cases. All of these were used to cover defects at the distal part of the middle phalanx.

May pentoxifylline improve lung function after one-lung flooding?

One-lung flooding makes the intraoperative sonography of round pulmonary lesions possible. During the flooded phase, the flooded lung suffers a significant reduction in perfusion. After ischemia and reperfusion, neutrophil granulocytes lead to further tissue injuries. A study was made on four animals to determine whether administration of pentoxifylline--a potent inhibitor of granulocyte adhesion to the endothelium--improves lung function after one-lung flooding. Two animals were subjected to thoracotomy with extended hemodynamic monitoring. Thoracoscopy was performed on two other animals, which were extubated after the flooding liquid was drained and survived for 24 degrees h. A bolus of 1 mg/kg of pentoxifylline was administered at the time of thoracotomy/thoracoscopy. followed by continuous infusion of pentoxifylline at a rate of 1.5 mg/kg per hour until 30 degrees min after reventilation (thoracotomy), or until extubation, respectively. The control group consisted of animals employed in previous experiments. Except for pentoxifylline administration, they were subjected to identical experimental conditions. The control group for the thoracotomy experiment comprised 14 animals, that for the thoracoscopy experiment three animals. The experiments proved that 30 degrees min after the draining of the flooding liquid and reventilation, all four pentoxifylline-treated animals had a higher partial arterial oxygen pressure and a lower pulmonary shunt volume compared with the control animals. In the two animals that survived, a positive effect on lung function was no longer detectable 24 degrees h after extubation. The administration did not lead to a drop in the pulmonary arterial pressure and did not cause any hemodynamic changes other than a moderate tachycardia.

One-lung flooding for video-assisted thoracoscopic surgery in animal experiments on pigs--oxygenation and intrapulmonary shunt.

Unilateral flooding of the lung after intubation with a double-lumen tube makes intraoperative sonography of the lung during video-assisted thoracoscopic surgery possible. After flooding with 15 ml/kg, the arterial partial oxygen pressure (with FiO2=1.0) is higher than that in total atelectasis by about 100 mmHg, while it is only slightly less than that during bilateral lung ventilation. Compared to total atelectasis, lung flooding reduces the pulmonary right-to-left shunt volume. The pulmonary function normalizes within 8 h after the operation.

Wet-to-dry ratio of lung tissue and surfactant outwash after one-lung flooding.

Unilateral flooding of the lung after intubation with a double-lumen tube enables intraoperative sonography of the lung tissue. The flooding restricts the pulmonary blood stream of the flooded lung in a relevant degree and thus reduces the right-to-left shunt volume. The deficient perfusion of the lung tissue during the flooded phase might cause capillary permeability disorders and secondary oedema development. This can be determined by examination of extravascular lung water (EVLW) after draining and reventilation of the flooded lung. Although one-time unilateral lung flooding must be distinguished from bronchopulmonary lavage, it is interesting to study the effects of flooding on the surfactant system. The wet-to-dry ratio of the lung tissues of 13 female pigs was ascertained at different times following one-lung flooding (1 to 11 weeks). A trend towards an increased wet-to-dry ratio in the previously flooded lung was found only in the tissue samples taken 1 h after reventilation. After only 24 h, the two lungs no longer differed in their wet-to-dry ratio. In six pigs, the phospholipid content of the drained flooding liquid was determined. It was shown that the surfactant loss caused by flooding was maximally 47% of the calculated surfactant pool of the respective lung.

Hemodynamics and gas exchange during experimental one-lung fluid flooding in pigs.

One-sided fluid flooding of the lung after intubation with a double-lumen tube facilitates pulmonary sonography during surgery. Arterial blood pressure, cardiac index, and heart rate remained unchanged during one-lung fluid flooding in healthy animals. The arterial PO(2) was greater by about 100 mmHg after flooding one lung with 15 ml/kg fluid and ventilation with a FiO(2) of 1.0 compared with total atelectasis. This seems to be identical to a continuos positive airway pressure level of 5 cm H(2)O with pure oxygen on the nonventilated lung. The one-sided fluid flooding induced a statistically significant increase in pulmonary artery pressures and pulmonary capillary wedge pressure. In comparison with total atelectasis, fluid flooding in tendency reduced the pulmonary right-left shunt and increased the arterial PO(2).

Simulation of lung lesions for validating the sonography of the flooded lung.

The quality of sonography of a unilaterally flooded lung needs to be validated on lesions of different echogenicity, size and subpleural position. Lesions were simulated in 12 young pigs with three different methods. After transbronchial (method 1) or transpleural puncture (method 2), diverse substances were injected into the lung. After 4 weeks, the thorax was opened and the lung flooded for the sonographic location of the lesions. In method 3, pulmonary lesions were simulated in an acute experiment after thoracotomy by transpleural injection or by filling of a Fogarty catheter balloon and were located sonographically. Transbronchial injection of alcohol invariably led to subsegment atelectasis. Only 25% of thoracoscopically controlled transpleural injections produced focal lesions in experiments in which the animals survived. Representative lesions were found only after alcohol injections. Transpleural injection of blood or a blood/Echovist suspension (method 3) simulated isoechogenic or echo-rich lesions with indistinct boundaries. By filling a Fogarty catheter balloon with saline solution or Echovist suspension, we succeeded in simulating echo-free or echo-rich lesions with smooth contours, located in different subpleural depths. After unilateral lung flooding, sonography successfully detected the locations of all these lesions and revealed their correlation with functional structures. Sonography of the flooded lung might be helpful in the intraoperative location of lesions, especially in the context of video-assisted thoracoscopic surgery.

[Hyponatremia and lung edema in endometrium ablation with rollerball ablation]. / Hyponatriämie und Lungenödem bei Endometriumablation mit der Rollerballelektrode.

OBJECTIVE: Absorption of hypotonic irrigating solution with consecutive severe hyponatremia is a potential risk of the endometrial rollerball ablation procedure. MATERIAL AND METHODS: We report the case of a 45-year-old female, who underwent an endometrial rollerball ablation procedure. RESULTS: After irrigating the uterine cavity for 45 min with 10 1 of 2.7% Sorbitol and 0.54% Mannitol she developed clinical signs of pulmonary edema with severe hyponatremia. CONCLUSIONS: A TUR-like syndrome as a potential risk of the rollerball ablation procedure is discussed briefly. Strategies to minimize the risk and to early detect the TUR-like syndrome are suggested.

Lung flooding--a new method for complete lung sonography.

A sonographic examination of the lung has so far been impossible because of sound reflection. In conjunction with video-assisted thoracoscopic surgery, lung sonography would be helpful to make up for the lack of direct palpation. Animal experiments with pigs were performed to find out whether lung sonography becomes possible following bronchoalveolar flooding with a suitable liquid. The lung was filled with whole electrolyte solution through the left leg of a double-lumen endotracheal tube after resorption atelectasis (method 1) or compressive atelectasis (method 2). As an alternative, liquid perfluorocarbon was used (method 3). Under atelectasis, the lung thus flooded was investigated by ultrasound applied transpleurally and endobronchially. The first results proved that lung flooding is possible if certain prerequisites are fulfilled. Perfluorocarbon flooding led to total sound absorption which prevented sonography, whereas flooding with whole electrolyte solution made complete lung sonography possible, making visible the intrapulmonary vessels, bronchi and peribronchial lymphatic nodes. Measurements proved that the unilateral flooding caused no significant changes in the arterial and central venous pressure nor in transcutaneous oxygen saturation.

[Effect of rocuronium in sufentanil/isoflurane and sufentanil/propofol anesthesia]. / Wirkung von Rocuronium bei Sufentanil/Isofluran- und Sufentanil/Propofol-Anästhesie.

It is a well-known fact that the duration of the effect of non-depolarizing neuromuscular blocking agents is influenced by other anaesthetics. Etomidate, propofol and nitrous oxide have no influence on the duration of effect of rocuronium, but a prolongation of the rocuronium effect under the influence of isoflurane has been described. In this study, we investigated the onset time, duration of effect and recovery index of rocuronium in isoflurane/N2O/sufentanil anaesthesia compared with these parameters in propofol/N2O/sufentanil anaesthesia. Forty patients (10 men and 30 women aged 47.5 +/- 13.0 years, ASA 1-2) were included in the investigation. Anaesthesia was induced by intravenous application of 20 mg etomidate, 0.15-0.2 micrograms/kg sufentanil and 0.9 mg/kg rocuronium. In 20 patients, anaesthesia was supplemented with 0.3-0.8 Vol.% (endexpiratory) isoflurane in a mixture of 30% O2 and 70% N2O (group A). In another 20 patients breathing 30% O2 and 70% N2O propofol (2-6 mg/kg/h) was infused continuously (group B). Onset time, duration of action and recovery index of rocuronium were measured with a nerve stimulator (train-of-four mode). The patients were intubated 60 seconds after completing the rocuronium injection and the intubation conditions were estimated clinically. The onset time amounted to 47.6 +/- 17.8 seconds (group A) and 58.1 +/- 13.6 seconds (group B). In group A, a mean duration of action of 54.3 +/- 13.8 minutes and in group B a mean duration of action of 53.9 +/- 18.9 minutes were measured. The recovery index amounted to 21.2 +/- 10.6 minutes in group A and 17.6 +/- 5.8 minutes in group B. The differences in onset time and recovery times were not significant. Significant changes in arterial blood pressure or heart rate were not observed. The intubation conditions after 60 seconds were excellent in 34 patients (85%) and good in 6 patients (15%). It can be concluded that in comparison with anesthesia maintained by propofol/sufentanil and nitrous oxide/oxygen, the relatively low but necessary supplementation with isoflurane instead of propofol does not lead to a clinically relevant amplification of the relaxing effect of rocuronium.

[Normal variation of arterial liver supply in mesenterico-celiacography]. / Normvarianten der arteriellen Leberversorgung in Mesenterico-Coeliacographien.

Progress in operative techniques in surgery of the upper abdomen necessitates extensive preoperative diagnostic studies. Mesenterico-coeliacography along with CAT-SCAN form the basis for effective operative planning. In the angiography, the clinician is often confronted by variations in the arterial supply of the liver. These variations of the norm which are scarcely mentioned in anatomical textbooks must be carefully taken into consideration by the surgeon. In order to clarify the operative significance of these variations, we have conducted a retrospective study of the angiographies of the truncus coeliacus as well as of the arteria mesenterica superior. We found variations in 25.5% of 204 angiographies. The incidence of deviant and accessory hepatic arteries was 33.8% and of variations in the truncus coeliacus was 6.7%. These variations of the norm are discussed as to clinical and embryological aspects.