[Bony contact in arthritic and healthy elbow joints : Studies in cadaveric specimens]. / Knöcherne Kontaktpunkte im arthrotischen und gesunden Ellenbogengelenk : Studie am humanen Leichenpräparat.

BACKGROUND: Arthroscopic and open debridement arthroplasty for elbow arthrosis produce excellent results. Resection of the tip of the olecranon and coronoid, as well as debridement of the associated fossae, is frequently described as sufficient for restoring range of motion and reducing pain. OBJECTIVES: The purpose of this study was to demonstrate that medial and lateral osteophytes of the olecranon and the coronoid usually mark the first bony contact and may, therefore, restrict range of motion. MATERIAL AND METHODS: 11 fresh-frozen elbows were dissected. The fossae were coated with Optosil P Plus (C-silicone), and maximal flexion and extension was simulated. The distribution of C­silicone impressions was documented. 6/7 donors were male. The mean age at the time of death was 82 . RESULTS: Out of 11 elbows, 4 exhibited arthritic changes. All arthritic elbows showed marginal osteophytes of the olecranon without characteristic dipping of the olecranon into its fossa. In 1/4 cases, additional osteophytes at the side of the coronoid were detected (in comparison to 1/7 in healthy elbows). CONCLUSION: The distribution of osteophytes in elbow arthrosis may be underestimated. Many clinicians describe a resection of the tip of the olecranon and the coronoid and debridement of the related fossa as sufficient. Our study supports the theory that marginal osteophytes, especially of the olecranon, should be resected during debridement arthroplasty, since the distribution of bony contact differs in arthritic and healthy elbows.

[Performance control after arthroscopic arthrolysis with capsulectomy in fresh-frozen elbow joints]. / Erfolgskontrolle nach arthroskopischer Arthrolyse mit Kapsulektomie am Ellenbogengelenk im Fresh-frozen-Präparat.

BACKGROUND AND OBJECTIVE: Posttraumatic or postoperative movement restrictions in elbow joints can often occur (including capsular contracture) and can generate everyday limitations. In persistent elbow stiffness, arthroscopic arthrolysis with removal of the dorsal and ventral capsule portions can be carried out. The purpose of this study was to assess the efficacy of arthroscopic capsulectomy by means of an in vitro anatomical study. METHODS: A standardized elbow arthroscopy with ventral and dorsal capsulectomy was performed and image-documented in five fresh-frozen elbow specimens. Subsequently, open dissection of the elbow joint was performed to analyze the amount of residual capsule by means of photodocumentation of the specimens. RESULTS: Regardless of the surgeon and surgical experience, anterior and posterior remnants of the capsule remained in all specimens. Dorsal capsule strands around the standard arthroscopy portals were noticed particularly more often in the area of the high dorsolateral camera portal. An incomplete capsulectomy was seen on the ulnar side at the level of the posterior medial ligament (PML) in the immediate vicinity of the ulnar nerve. Ventrally, a capsulectomy was performed from the radial side and also the ulnar side until the brachialis muscle and additionally a complete capsulectomy as far as the anterior medial ligament (AML) and radial collateral ligament (RCL) was achieved. The capsule was completely resected in a proximal direction. Distally, irrelevant capsular remnants were found in the region of the annular ligament and distal of the tip of the coronoid process. CONCLUSION: Arthroscopic arthrolysis can be performed with a high degree of radicality. The radicality must be self-critically taken into account in one's own action. The radicality of the portal change may even be higher ventrally than with an isolated column procedure. On the other hand, it must be critically considered that posteriorly, the PML cannot be adequately addressed by means of arthroscopy due to the risk of ulnar nerve injury. Portal changes might help to enable a more complete visualization of the joint capsule and may avoid leaving possibly relevant remnants of the capsule. If a release of the PML is required, this may have to be carried out in combination with an ulnar nerve release in a mini-open technique.

[Hybrid operating theater]. / Hybridoperationssaal.

A hybrid suite is an operating theater with imaging equipment equivalent to that used in an angiography suite with computed tomography (CT) and magnetic resonance imaging (MRI). They are often situated outside the operating room area and typically serve as multifunctional rooms designed to support a variety of catheter-based endovascular procedures and open surgery to be performed in the same location. The possibility to perform these in the same location facilitates the combination of both approaches to so-called hybrid procedures. Typical clinical applications of hybrid suites are cardiac, thoracic and vascular surgery, neurosurgery and neuroradiology, as well as orthopedics and traumatology. Transcatheter aortic valve implantation (TAVI) is significantly less invasive than a classical approach by open surgery. Patients older than 75 years with relevant comorbidities benefit most from the minimally invasive interventional approach. There has been a paradigm shift in the management of vascular diseases from open surgical repair to new percutaneous endovascular interventions with good early outcomes. Of particular interest in this context is the ability to block the part of the aorta proximal to the aneurysm with a catheter-based dilatation balloon. Progress in image fusion technology and intraoperative navigation has led to an increased acceptance of hybrid suites in orthopedics and traumatology. The complex care of high-risk patients most often outside the operating theater area is a challenge for the anesthesia team. This demands meticulous planning on behalf of the anesthesiologist to ensure an appropriate and safe strategy for anesthesia, intraoperative monitoring, vascular access and the need for additional equipment. A thorough understanding of the complexity of procedures is vital and a series of questions must be addressed: what is needed to safely administer anesthesia in this environment? What additional resources would be needed for an emergency situation? Is the patient being kept safe from radiation hazards? Moreover, logistics may become an issue as the hybrid suite is most often delocalized. In addition, many procedures realized in a hybrid suite require a multidisciplinary approach and therefore teamwork and professional communication are mandatory. Anesthesiologists need to have an integral role in the hybrid suite team, understanding and anticipating the risks for patients and leading the organization of workflow. The challenge in anesthesia is to ensure that when patients are taken to these complex environments the resources available enable high standards of care to be provided. With future developments in imaging technology combined with more powerful hardware and software, a far greater integration of all these imaging and navigation technologies will be seen in future operating rooms. Finally, patients are becoming more aware of medical developments via the world wide web and increasingly request what they consider to be state of the art treatment.

[Residual neuromuscular blockade]. / Neuromuskuläre Restblockade.

Even small degrees of residual neuromuscular blockade, i. e. a train-of-four (TOF) ratio >0.6, may lead to clinically relevant consequences for the patient. Especially upper airway integrity and the ability to swallow may still be markedly impaired. Moreover, increasing evidence suggests that residual neuromuscular blockade may affect postoperative outcome of patients. The incidence of these small degrees of residual blockade is relatively high and may persist for more than 90 min after a single intubating dose of an intermediately acting neuromuscular blocking agent, such as rocuronium and atracurium. Both neuromuscular monitoring and pharmacological reversal are key elements for the prevention of postoperative residual blockade.

[Neuromuscular monitoring]. / Neuromuskuläres Monitoring.

The effect of muscle relaxants varies among people and the extent, the duration and recovery from the neuromuscular block varies. Clinical tests cannot determine the effect of muscle relaxants which is only possible with neuromuscular monitoring. The relaxometry procedure measures the muscular response to electrical stimulation of the corresponding motor nerve and the adductor pollicis muscle is mostly used; however, this muscle is not representative for other muscle groups, such as the muscles of the larynx and diaphragm. The muscles of the larynx and diaphragm are more resistant against nondepolarizing muscle relaxants than the adductor pollicis muscle. The train of four (TOF) is used at the beginning of surgery for monitoring of the optimal time for tracheal intubation; moreover, the TOF is used during surgery for monitoring of the muscle blockade and at the end of surgery for monitoring recovery. Monitoring of deep muscular blockades, however, is only possible with the posttetanic count (PTC) when there are no TOF counts. The PTC allows repetition and higher doses of muscle relaxants during abdominal surgery; therefore, conditions for surgery are optimal and cumulation of muscle relaxants is avoided.

Acceleromyography to assess neuromuscular recovery: is calibration before measurement mandatory?

BACKGROUND: Acceleromyography has been shown to be an appropriate method in the detection of residual paralysis. However, the clinical importance of an individual calibration of the device in the single patient to improve reliability in detecting residual paralysis remains unclear. METHODS: Observational study in 100 patients undergoing general anaesthesia with endotracheal intubation and a neuromuscular block with atracurium. In all patients, an individually calibrated acceleromyograph was used to estimate a possible residual block at the end of surgery. Immediately after finishing the calibrated measurements at the end of surgery, a non-calibrated measurement was performed. Agreements between the two measurements were tested using Cohen's κ and a Bland-Altman analysis. RESULTS: Data from 96 patients were analysed. At the end of surgery, a discordance in the calibrated and the non-calibrated train-of-four ratio was found in 88 patients. Bland-Altman analysis showed a mean (bias) of 0.01, with limits of agreement of 0.15/-0.15. κ was calculated with κ=0.84 for the absence or presence of a potential residual block if defined as a train-of-four ratio of 1.0 as a threshold. CONCLUSIONS: The results imply a good agreement in the detection of the presence or absence of a residual neuromuscular block between calibrated and non-calibrated acceleromyography if a train-of-four ratio of 1.0 has been chosen as the threshold. However, the estimated train-of-four values are not transferable between calibrated and non-calibrated measurements.

Monitoring neuromuscular block: an update.

The first part of this article presents an update of the basic considerations of neuromuscular monitoring. It emphasises the need to assure supramaximal stimulation, to place the stimulating electrodes correctly and to use appropriate sites for nerve stimulation as well as appropriate stimulation patterns. The second part focuses on current developments and ongoing discussion. The authors describe the performance of acceleromyography and the need for initial calibration when using these quantitative devices.

[Sugammadex. New pharmacological concept for antagonizing rocuronium and vecuronium]. / Sugammadex. Neues pharmakologisches Konzept zur Antagonisierung von Rocuronium und Vecuronium.

Up to now only acetylcholine esterase inhibitors, such as neostigmine, were available as antagonists of residual neuromuscular blocks. Sugammadex is a modified gamma-cyclodextrin that binds rocuronium and chemically similar aminosteroidal muscle relaxants, such as vecuronium. The underlying mechanism of action is new and differs completely from that of acetylcholine esterase inhibitors. This review summarizes data published so far within the framework of the licensing procedure about the efficacy, safety and side-effects of sugammadex and presents potential new anesthesiological concepts using this compound.

[Application of neuromuscular monitoring in Germany]. / Einsatz des neuromuskulären Monitorings in Deutschland.

The aim of the present study was to evaluate application customs of neuromuscular monitoring in hospitals and private practice. Of the 3,260 questionnaires sent out, 2,182 could be analyzed. Of these 54% were from anaesthetists in private practice, 41% from heads of hospital anaesthesia departments and 5% from heads of level 1 hospital anaesthesia departments. In 12.1% of the hospital departments and 66.7% of private practices, no neuromuscular monitoring was available at all. In both hospital departments and private practices, clinical signs were the most often applied criteria for timing of reinjection of myorelaxants as well as for evaluation of neuromuscular recovery.

[Postobstructif pulmonary oedema after endotracheal extubation at the recovery of general anaesthesia]. / Oedème aigu du poumon postobstructif après extubation trachéale au réveil d'une anesthésie générale.

We report two cases of postobstructif pulmonary oedema occurring after extubation at the recovery of general anaesthesia and presenting some similarities. The young age of the patient and the occurrence of upper airway obstruction after extubation, as well as the radiologic nondependent distribution of alveolar pattern are typical. The underlying pathophysiology seems to be the mechanical disruption of the alveolar-capillary membrane.

Imaging the Parasinus Region with a Third-Generation Dual-Source CT and the Effect of Tin Filtration on Image Quality and Radiation Dose.

BACKGROUND AND PURPOSE: CT is the imaging technique of choice in the evaluation of midface trauma or inflammatory disease. We performed a systematic evaluation of scan protocols to optimize image quality and radiation exposure on third-generation dual-source CT. MATERIALS AND METHODS: CT protocols with different tube voltage (70-150 kV), current (25-300 reference mAs), prefiltration, pitch value, and rotation time were systematically evaluated. All images were reconstructed with iterative reconstruction (Advanced Modeled Iterative Reconstruction, level 2). To individually compare results with otherwise identical factors, we obtained all scans on a frozen human head. Conebeam CT was performed for image quality and dose comparison with multidetector row CT. Delineation of important anatomic structures and incidental pathologic conditions in the cadaver head was evaluated. RESULTS: One hundred kilovolts with tin prefiltration demonstrated the best compromise between dose and image quality. The most dose-effective combination for trauma imaging was Sn100 kV/250 mAs (volume CT dose index, 2.02 mGy), and for preoperative sinus surgery planning, Sn100 kV/150 mAs (volume CT dose index, 1.22 mGy). "Sn" indicates an additional prefiltration of the x-ray beam with a tin filter to constrict the energy spectrum. Exclusion of sinonasal disease was possible with even a lower dose by using Sn100 kV/25 mAs (volume CT dose index, 0.2 mGy). CONCLUSIONS: High image quality at very low dose levels can be achieved by using a Sn100-kV protocol with iterative reconstruction. The effective dose is comparable with that of conventional radiography, and the high image quality at even lower radiation exposure favors multidetector row CT over conebeam CT.

Newer neuromuscular blocking agents: how do they compare with established agents?

Rapacuronium bromide (rapacuronium; ORG-9487) is a nondepolarising muscle relaxant (NMBA) with a low potency [90% effective dose (ED90) 1 mg/kg], which to some extent is responsible for its rapid onset of action. Because of the high plasma clearance (5.3 to 11.1 mg/kg/min) of rapacuronium, its clinical duration of action following single bolus doses up to 2 mg/kg in adults is short (i.e. <20 minutes). Rapacuronium forms a pharmacologically active 3-desacetyl metabolite, ORG-9488, which may contribute to a delay in spontaneous recovery after repeat bolus doses or infusions. After rapacuronium 1.5 mg/kg clinically acceptable intubating conditions are achieved within 60 to 90 seconds in the majority of adult and elderly patients undergoing elective anaesthesia. However, in a rapid-sequence setting. intubating conditions are less favourable after rapacuronium 1.5 to 2.5 mg/kg than after succinylcholine. The most prominent adverse effects of rapacuronium (tachycardia, hypotension and bronchospasm) are dose-related, and in particular pulmonary adverse effects are observed more frequently under conditions of a rapid-sequence induction in adults. Therefore, it seems worthwhile to consider only doses of rapacuronium < or = 1.5 mg/kg to facilitate rapid tracheal intubation, and to use succinylcholine or rocuronium rather than rapacuronium in a rapid-sequence setting. Rapacuronium, however, is a suitable alternative to mivacurium chloride (mivacurium) and succinylcholine for short procedures (e.g. ambulatory anaesthesia). Rocuronium bromide (rocuronium) is a relatively low-potent, intermediateacting NMBA. Its main advantage is the rapid onset of neuromuscular block whereby good or excellent intubating conditions are achieved within 60 to 90 seconds after rocuronium 0.6 mg/kg (2 x ED95), and within 60 to 180 seconds after smaller doses (1 to 1.5 x ED95). Larger doses of rocuronium (> or = 1 mg/kg) seem to be suitable for rapid-sequence induction under relatively light anaesthesia. However, it is still a matter of controversy whether, in the case of an unanticipated difficult intubation, the long duration of rocuronium administered in such large doses outweighs the many adverse effects of succinylcholine. Rocuronium has mild vagolytic effects and does not release histamine, even when administered in large doses. Rocuronium is primarily eliminated via the liver and its pharmacokinetic profile is similar to that of vecuronium bromide (vecuronium). Unlike vecuronium, rocuronium has no metabolite. Cisatracurium besilate (cisatracurium), the IR-cis, 1'R-cis isomer of atracurium besilate (atracurium) is approximately 4 times more potent than atracurium. The onset time of cisatracurium is significantly slower than after equipotent doses of atracurium. The recommended intubating dose is 0.15 to 0.2 mg/kg (3 to 4 times ED95). Over a wide range of clinically relevant doses the recovery properties of cisatracurium are affected by neither the size of the bolus dose nor by the duration of infusion. Unlike atracurium, cisatracurium does not trigger histamine release. Like atracurium, cisatracurium undergoes Hofmann elimination. In contrast to atracurium, cisatracurium does not undergo hydrolysis by nonspecific plasma esterases. Moreover, about 77% of the drug is cleared by organ-dependent mechanisms.

Properties of maltose-inducible alpha-glucosidase MalL (sucrase-isomaltase-maltase) in Bacillus subtilis: evidence for its contribution to maltodextrin utilization.

Recently, we identified the maltose inducible alpha-glucosidase MalL of Bacillus subtilis. The malL gene encodes a 561-residue protein with amino acid identities to several alpha-glucosidases and is located in a nine-gene spanning gene cluster, which is presumably organized in an operon. MalL was overproduced, purified, and its enzymatic characteristics were described in more detail. This characterization of the enzyme showed a protein stable up to 37 degrees C after temperature treatment for 15 min and exhibiting an optimal reaction temperature of 42 degrees C. Various disaccharides such as sucrose, maltose, and isomaltose were hydrolyzed with different efficiencies. MalL also hydrolyzes longer maltodextrins from maltotriose up to maltohexaose, but not maltoheptaose, palatinose, isomaltotriose, or isomaltotetraose. MalL expression is subject to both maltose induction and carbon catabolite repression. In this article, we present data demonstrating that induction of MalL expression also occurs when starch, amylose, or glycogen are present in the growth medium. The hydrolysis of these substrates by alpha-amylase presumably leads to products which, when taken up into the cytoplasm, trigger the initiation of maltose operon transcription. Furthermore, MalL expression varies temporally, showing a second induction in the stationary growth phase.