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Description / Table of Contents: Abstract When heart-lung machines made extracorporeal circulation possible in the fifties, cardiac surgeons gained virtually unrestricted access to the resting, motionless heart. Valve repair and reconstruction, in particular, made great progress as a result of extracorporeal circulation. While the distinct advantages of extracorporeal circulation for cardiosurgery remain undisputed, awareness of the significant perioperative risks of extracorporeal circulation for the patient has been increasing in recent years. This has lead to an interest in alternative cardiosurgical techniques avoiding extracorporeal circulation. Inspired by minimally-invasive procedures in abdominal surgery, cardiosurgical instruments as well as surgical techniques of access to the heart and large thoracic vessels were systematically modified leading to today's minimally-invasive cardiosurgical procedures such as off-pump coronary artery bypass grafting on the beating heart. Similarly, in the field of cardiac valve repair, new cannulation techniques for instituting extracorporeal circulation make median sternotomy unnecessary. The developments described above have lead to the recent introduction of robot-assisted techniques with or without extracorporeal circulation, which are expected to make possible in the near future the performance of the whole range of cardiosurgical procedures with minimal surgical trauma. The introduction of the new techniques has changed the intraoperative responsibilities of the anesthesiologist. The present article will therefore describe both the new surgical techniques as well as the new tasks required of the anesthesiologist, in particular with regard to cannulation and monitoring. Since a number of terms in minimally-invasive cardiosurgery are not precisely defined, a clear description of the various surgical techniques is also provided.

Description / Table of Contents: Abstract Objective: Elective tracheostomy has become an established treatment modality in modern intensive care medicine, and the number of percutaneously performed tracheostomies is steadily increasing. The Ciaglia Blue Rhino (CBR) represents another percutaneous technique in which the tracheostoma is formed by one-step dilation. Our study presents the technique itself and the early clinical experiences. Methods: In 20 adult patients on long-term ventilation, CBR was done. After puncture of the trachea in typical manner, dilation of the tracheostoma was achieved in one single step by means of a curved dilator with a special hydrophilic coating. Then, the tracheostomy tube was inserted over a curved loading dilator. Practicability and safety were determined as well as gas exchange during the procedure by means of arterial blood gas samples. Results: As a result of the dilator’s hydrophilic coating, dilation of the tracheostoma was rapidly achieved within 152±22 s, virtually free from resistance of the trachea or the cervical tissues. Complications such as bleeding, aspiration or postoperative infection of the stoma were not noted in any of our patients. Fractures of isolated tracheal cartilage rings were seen in 5 patients, however, no therapeutic intervention was necessary. In terms of perioperative gas exchange, pre- and postoperative levels of FiO2, PaO2, PaCO2 and the oxygenation index (PaO2/FiO2) did not change significantly. Conclusions: Based on our early clinical experience, Ciaglia Blue Rhino represents a new method that may combine the typical advantages of each of the other techniques for percutaneous tracheostomy (i.e. Ciaglia, Griggs, Fantoni) in one single technique. This method is distinguished by a high level of safety and practicability. However, further comparative trials need to be done before a definitive judgement can be made.

Description / Table of Contents: Abstract A combination of epidural opioids with local anaesthetics has been used to improve pain relief during labor and to reduce side effects, such as muscle weakness, usually seen when local anaesthetics are used alone. The addition of epidural fentanyl (F) produces highly effective analgesia, the only side effect being mild itching. Initial trials investigated the improvement in analgesia after a single administration of F during first- but not during second-stage labor. Even though pain perception during second-stage labor under epidural analgesia with local anaesthetics can be severe, the addition of opioids was avoided for fear of neonatal or maternal depression. A recent report found maternal and umbilical plasma concentrations following injection of 100 μg F to be safe and the investigators speculated that repeated addition of epidural/F to injections of local anaesthetic may prove beneficial for the parturient without exposing the mother or fetus to risk. We therefore studied maternal analgesia, maternal and umbilical plasma levels and associated side effects following repeated addition of 100 μg F to bupivacaine epidural analgesia during labor. Methods. Following institutional and governmental approval 53 parturients were randomly assigned to receive either 8 ml bupivacaine 0.25%+0.1 mg fentanyl (B+F group; n=28) or 8 ml bupivacaine 0.25%+2 ml saline (BUP group; n=25) in an epidural catheter at L2/3. The same dose was reinjected upon the patients' request regardless of the degree of cervical dilatation. Blood pressure, heart rate, respiratory rate and the incidence of side effects were recorded before and following each epidural injection. Pain relief was determined at each injection and following cord clamping using the visual analogue pain scale (VAS; 0–100 mm). Maternal venous blood samples were collected to measure plasma F concentrations before and 20 and 40 min after each injection and at birth when umbilical venous and arterial blood was obtained. After centrifugation the samples were maintained at −20° C and then analyzed by radioimmunoassay. At delivery, Apgar scores and umbilical venous and arterial blood gas values were determined. Results. Both groups were comparable for age, weight, height, gestational age and parity. A total of 48 epidural injections were evaluated in the B+F group, 43 in the BUP group. No statistically significant group difference was found between the frequency of injections per delivery (B+F: 2.2; BUP: 1.8); regarding the time between the initial and the first top-up dose (B+F: 144 min; BUP: 140 min) or regarding the interval between the last injection and birth (B+F: 94 min; BUP; 90 min). However, the quality of pain relief during labor and particularly at birth was significantly improved by F (mean VAS in B+F group: 6 mm; mean VAS in BUP group: 42 mm). Mild itching was observed in 43% of patients receiving F, moderate shivering in 13% versus 40% in patients not receiving F. At control mean maternal F plasma levels were not zero but 0.25 ng/ml. After the initial injection and following the first and second top-up dose mean maximum maternal F plasma concentrations were 0.54 ng/ml (±0.32; ±SD), 0.88 ng/ml (±0.62) and 1.06 ng/ml (±0.4) (range 0.18–2.76 ng/ml), respectively. The increase in maternal F concentrations with increasing injection frequency was statistically significant (P〈0.02). Mean umbilical venous and arterial F concentrations at birth were 0.72 ng/ml (±1.16) and 0.62 ng/ml (±0.52). No significant group differences were found regarding Apgar scores or umbilical blood gas analyses. In one newborn, radioimmunoassay resulted in unexplainably high umbilical F concentrations without any clinical signs of sedation, depressed vigilance and without any sequellae. Discussion. Repeated addition of 100 μg F to epidural anaesthesia with bupivacaine significantly improves analgesia and provides pain relief not only during the first but also through the very painful second stage of labor. In this study, F did not affect the onset or the duration of analgesia, probably due to the fact that bupivacaine was used at a fixed and (compared to other studies) relatively high concentration. We did not observe clinically relevant side effects in the mother or the newborn. Although epidural injections of 100 μg F were repeatedly administered, the mild dose-dependent increases of maternal and of umbilical plasma F concentrations had no effect and caused no clinical signs of depression. The specificity of radioimmunoassay for fentanyl in parturients is questioned.

Description / Table of Contents: Abstract Due to its important physiological and pathophysiological actions, the pluripotent signaling molecule nitric oxide (NO) is increasingly of interest in clinical medicine. Despite increasing use by anaesthetists in inhalational therapy for intensive care patients with respiratory distress syndrome, the potential interactions of anaesthetic agents and NO have thus far received little attention. The literature available to date on this topic is somewhat controversial, and highlights the need for additional research in this area. This review summarises the pertinent literature in this area for the anaesthetist and describes potential mechanisms by which anaesthetics may interfere with the synthesis and/or effects of NO in the human body.

Description / Table of Contents: Abstract Tracheostomy is one of the oldest surgical procedures and in the past decades has become the method of choice in the management of patients requiring long-term mechanical ventilation. At present, several alternatives exist to conventional surgical tracheostomy, such as the percutaneous dilatational techniques according to Ciaglia (PDT), Griggs (GWDF), and Schachner (Rapitrach). In particular, PDT according to Ciaglia which was introduced in 1985, has been recognized as an equally safe, but less expensive procedure than conventional tracheostomy. Fantoni’s translaryngeal percutaneous technique is another new and safe procedure, which was first performed in 1996. Nonetheless, we believe that percutaneous procedures should only be performed by experienced physicians who are well-trained in both endotracheal intubation and mask ventilation. Furthermore, the capacity to perform surgical tracheostomy immediately in case of complications should be given. Only if the contraindications are carefully observed, will these new procedures retain their value and benefit in airway management of long-term ventilated patients.

Description / Table of Contents: Abstract The incidence of postoperative myocardial infarction (MI) is proportional to the incidence of myocardial ischaemic episodes. Therefore, the prevention of such episodes is of great clinical importance. Methods. In 90 patients undergoing coronary artery bypass grafting (CABG), perioperative i.v. treatment with either nitroglycerin (NTG), diltiazem (DIL), or the combination of DIL/NTG was used until arrival in the intensive care unit. Myocardial ischaemic episodes were monitored with an automatic ECG-ST-trend analyser (Marquette 7010). Results. Significantly less ischaemic episodes were seen in the DIL group (6.7%) compared to the NTG group (13.2%) or DIL/NTG group (13.5%). Furthermore, significantly less ischaemic episodes were associated with relevant haemodynamic alterations in the DIL group (58.1%) compared to the NTG (89.1%) or DIL/NTG group (80.0%). Increases in heart rate were markedly reduced in the DIL group. Discussion. DIL results in marked haemodynamic stabilisation during CABG, especially in the period immediately after extra-corporeal circulation. This might serve as an explanation for the significant reduction in ischaemic episodes in the DIL group compared to the other two groups. Therefore, perioperative prevention of myocardial ischaemia with the calcium antagonist DIL seems to be favourable in patients during CABG.