Controlling quantum systems by embedded dynamical decoupling schemes.

A dynamical decoupling method is presented which is based on embedding a deterministic decoupling scheme into a stochastic one. This way it is possible to combine the advantages of both methods and to increase the suppression of undesired perturbations of quantum systems significantly even for long interaction times. As a first application the stabilization of a quantum memory is discussed which is perturbed by one- and two-qubit interactions.

Knee joint arthroplasty in a patient with haemophilia A and high inhibitor titre using recombinant factor VIIa (NovoSeven): a new case report and review of the literature.

Elective orthopaedic surgery is regularly withheld from patients with haemophilia and high inhibitor titre despite the presence of severe arthropathy and urgent medical need. A knee joint arthroplasty was performed in a patient with severe haemophilia A and a high inhibitor titre using recombinant factor VIIa (rFVIIa) as the sole coagulation factor. There was no abnormal bleeding during surgery although an increased blood loss through surgical drains did occur during the first 6 h postoperatively. Rehabilitation was started on day 1 and continued for 3 months. Walking commenced on day 4. After 1 year of follow-up, the clinical outcome of surgery was considered excellent with no pain, knee mobility at 0-5-90 degrees, and an International Knee Society score of 95/100. No rFVIIa-associated side-effects or thrombotic complications were reported. In conclusion, knee joint arthroplasty is now an option for haemophilia patients with a high inhibitor titre. An international review of all available data on elective orthopaedic surgery in inhibitor patients is required so that the optimal treatment regime can be defined and the short- and long-term risk-benefit ratio of surgery compared to that of noninhibitor patients.

Block of the brachial plexus branches by the humeral route. A prospective study in 503 ambulatory patients. Proposal of a nerve-blocking sequence.

BACKGROUND: Brachial plexus is usually approached by the supraclavicular or axillary route. A technique for selective blockade of the branches of the plexus at the humeral canal using electrolocation has recently been proposed. The aim of the present study was to assess the feasibility of this technique in the ambulatory patient and to determine the optimal sequence of nerve-blocking. METHODS: The nerves originating from the brachial plexus were located in the humeral canal, at the junction of the proximal and the middle third of the arm, with a stimulator and blocked using either lidocaine or a mixture of lidocaine and bupivacaine, depending on the anticipated duration of surgery. The minimal stimulating intensity eliciting an adequate response, type of local anaesthetic and injected volume, and time of onset of surgical anaesthesia were collected. RESULTS: The study included 503 consecutive ambulatory patients due to undergo surgery of the elbow, wrist or hand in one year. Suitable anaesthesia was obtained with the humeral blockade in 82.1% of cases. In the remaining 17.9%, an additional block at the elbow was required, mainly for ulnar and median nerves. The onset times of sensory blocks were the longest for the median nerve, similar for the radial and ulnar nerves, shorter for the musculocutaneous nerve and the shortest for the medial brachial and antebrachial cutaneous nerves. The difference was more significant with the lidocaine-bupivacaine mixture, than with lidocaine alone (P<0.001 vs P<0.05, respectively). The onset times of motor blocks were the longest for the median nerve (P<0.05) and the shortest for the musculocutaneous nerve (P<0.001). Neither nervous nor vascular complications occurred. CONCLUSION: This study shows that the nerve block at the humeral canal is an efficient and safe technique. Considering the onset times of nerve blocks, the following sequence for blockade can be recommended: median, ulnar, radial, musculocutaneous, medial (brachial and antebrachial) cutaneous nerves. The selective blockade of the main nerves of the upper limb at the humeral canal can be recommended for surgery of the forearm and the hand in the ambulatory patient.

[Microsurgical transoral decompression in diseases of and injuries to the cranio-cervical junction]. / Die mikrochirurgische transorale Dekompression bei Erkrankungen und Verletzungen des kraniozervikalen Ubergangs.

Besides the microsurgical ventral decompression for treatment of cervical disc prolapses, combined with an intercorporal fusion using an autologous bone graft from the iliac crest and a plate osteosynthesis, the microsurgical, transoral approach to the craniocervical junction has proven to be an effective procedure for adequate indications. Even for surgical treatment of diseases and injuries of the craniocervical junction ventral, anterolateral, lateral and dorsal approaches are applicable alone or in combination. The special anatomic and functional conditions of this region, however, obviously require that the indicational criteria for the various approaches differ from those selected for the other cervical segments. The postoperative complication risk requires that particulary critical consideration be given to the question of isolated transoral interventions. The same holds true for the question as the necessity for additional ventral stabilisation in combined dorsoventral interventions. This report is about 20 patients who underwent transoral decompression, about the indications and the procedure typical problems.

[Femur head preserving therapy, using vascular pedicled iliac bone graft, in segmental femoral head necrosis]. / Kopferhaltende Therapie mit dem gefässgestielten Beckenkammspan bei der segmentalen Hüftkopfnekrose. Spätergebnisse.

Various therapeutic options have been proposed in the treatment of femoral head necrosis ranging from conservative management to total hip arthroplasty. Since microsurgical techniques are routinely used in orthopaedic surgery, the importance of revascularization has increased in recent years. Vascularized bone grafting as well as various osteotomies have been considered for the stages II and III according to Ficat and II, III and IV of the criteria of the ARCO system respectively, which also bases on MRI-findings. We investigated the results of 80 patients with avascular necrosis of the femoral head treated with a vascular pedicled iliac bone graft, perfused by the A. circumflexa ilium profunda, between 1988 and 1996. Mean follow-up was 5.6 years. The evaluation was based on the harris hip score, clinical and radiological examination as well as a subjective assessment using a VAS (visual analog scale). The clinical results according to the harris hip score were good or excellent in 86.1%. These results correlate with the subjective assessment of pain and of the hip joint function with an average of 7.9 points using the VAS (max. 10 points). Unchanged radiological appearance over the follow-up period was observed in 47.5% using the ARCO criterias. Reviewing the studies using vascularized grafts, about 50% of the patients with a stage II and III according to Ficat and II, III and IV of the ARCO respectively show an unchanged stage of the disease 5-6 years after the procedure. Therefore, transplantation of a vascular pedicled iliac bone graft possibly offers the chance to intervene causally in the course of the disease with only little alteration of the biomechanics of the hip joint.

[Claude Bernard-Horner syndrome and its opposite, Pourfour du Petit syndrome, in anesthesia and intensive care]. / Le syndrome de Claude Bernard-Horner et son contraire, le syndrome de pourfour du petit, en anesthésie-réanimation.

OBJECTIVE: To analyse cases of Horner's syndrome (HS) and its opposite, Pourfour du Petit's syndrome (PPS), occurring in anaesthesia and intensive therapy with consideration of the data of current literature. DATA SOURCES: For this paper we have reviewed the French, English and German literature published in anaesthesia and intensive care journals using Medline search and the current textbooks. STUDY SELECTION: All observational studies on these syndromes, whether clinical cases or letters to the editor, form the basis for this article. DATA EXTRACTION: The articles were analysed mainly with regard to diagnosis, therapy and prognosis of syndromes due to iatrogenic causes. DATA SYNTHESIS: HS is caused by a paralysis of the ipsilateral sympathetic cervical chain and includes a ptosis of the upper eyelid, a slight elevation of the lower lid, a sinking of the eyeball, a constriction of the pupil, a narowing of the palpebral fissure, a nasal stuffiness associated with anhidrosis, and flushing of the affected side of the face. Regional anaesthesia (intra-oral anaesthesia, brachial plexus block, epidural anaesthesia whether by thoracic, lumbar or caudal approach, as well as interpleural analgesia) is the main anaesthetic cause for HS. HS due to the effect of a local anaesthetic is transient, it can precede a high spinal block and a cardiovascular collapse. HS from puncture of the internal jugular vein is most often permanent. When transient, HS regresses within 3 months after puncture. Other causes of HS include intraoperative posture, pleural drain, neck surgery, neck trauma. A mydriatic collyrium, such as phenylephrine, resolves ptosis for less than 1 hour and results in blurred vision from pupillary dilation. Major ptosis requires surgery. PPS is the reciprocal HS and is caused by a stimulation of the ipsilateral sympathetic cervical chain. PPS can precede HS. It carries a risk for conjunctivitis, keratitis and epiphora in case of major exophthalmia. PPS is often reported as an unilateral mydriasis. PPS has the same causes as HS. Myotic collyriums are relatively inefficient. Major lid retraction requires a tarsorraphy, pomades and nocturnal lid occlusion. A part of HS and most PPS occurring in anaesthesia and intensive care remain unrecognized or are recognized with delay, especially if they remain minor and transient or when they occur in unconscious patients, in horizontal posture.

Free vascularized muscle flap transplantation in the treatment of chronic osteomyelitis.

We are reporting our experience with the efficacy of free tissue transfer in treatment of chronic lower-extremity osteomyelitis; 23 latissimus dorsi flaps and 11 rectus abdominis flaps were used. In our series, success was achieved after a mean follow-up of 36.1 months in 79% and after additional wound debridement in 94%. Indications, methods, results and complications are reported.

Does uremic enterocolitis exist? A morphological and functional investigation of rat intestine in chronic renal insufficiency.

In rats a severe but compensated chronic renal insufficiency was induced by stepwise 9/10 nephrectomy. Despite this severe chronic renal insufficiency we observed no relevant pathological changes in the intestinal mucosa. In particular, we found no evidence of mucosal erosions, ulceration or pseudomembranous colitis, findings which are traditionally thought to be characteristic of the uremic state. This was also true of those animals dying prematurely from uremia. Thus serious doubts arise about the existence of "uremic enterocolitis", doubts which also proved justified after a critical review of the literature on human pathology.