Megahertz-rate ultrafast X-ray scattering and holographic imaging at the European XFEL.

The advent of X-ray free-electron lasers (XFELs) has revolutionized fundamental science, from atomic to condensed matter physics, from chemistry to biology, giving researchers access to X-rays with unprecedented brightness, coherence and pulse duration. All XFEL facilities built until recently provided X-ray pulses at a relatively low repetition rate, with limited data statistics. Here, results from the first megahertz-repetition-rate X-ray scattering experiments at the Spectroscopy and Coherent Scattering (SCS) instrument of the European XFEL are presented. The experimental capabilities that the SCS instrument offers, resulting from the operation at megahertz repetition rates and the availability of the novel DSSC 2D imaging detector, are illustrated. Time-resolved magnetic X-ray scattering and holographic imaging experiments in solid state samples were chosen as representative, providing an ideal test-bed for operation at megahertz rates. Our results are relevant and applicable to any other non-destructive XFEL experiments in the soft X-ray range.

Real-time spatial characterization of micrometer-sized X-ray free-electron laser beams focused by bendable mirrors.

A real-time and accurate characterization of the X-ray beam size is essential to enable a large variety of different experiments at free-electron laser facilities. Typically, ablative imprints are employed to determine shape and size of µm-focused X-ray beams. The high accuracy of this state-of-the-art method comes at the expense of the time required to perform an ex-situ image analysis. In contrast, diffraction at a curved grating with suitably varying period and orientation forms a magnified image of the X-ray beam, which can be recorded by a 2D pixelated detector providing beam size and pointing jitter in real time. In this manuscript, we compare results obtained with both techniques, address their advantages and limitations, and demonstrate their excellent agreement. We present an extensive characterization of the FEL beam focused to ≈1 µm by two Kirkpatrick-Baez (KB) mirrors, along with optical metrology slope profiles demonstrating their exceptionally high quality. This work provides a systematic and comprehensive study of the accuracy provided by curved gratings in real-time imaging of X-ray beams at a free-electron laser facility. It is applied here to soft X-rays and can be extended to the hard X-ray range. Furthermore, curved gratings, in combination with a suitable detector, can provide spatial properties of µm-focused X-ray beams at MHz repetition rate.

Real-world use of the sufentanil sublingual tablet system for patient-controlled management of acute postoperative pain: a prospective noninterventional study.

Objective: To evaluate the real-life effectiveness, safety, tolerability and patient-reported outcomes (PRO) of the sufentanil sublingual tablet system (SSTS) for postoperative pain management (POPM).Methods: This prospective, multicenter, noninterventional, study included adults with acute moderate to severe postoperative pain who self-administered sufentanil using the SSTS. Main outcome measures were pain intensity at rest (numerical rating scale [NRS]: 0 [no pain] to 10 [most intense pain imaginable]); most intense pain intensity (0-10); 4-point patient assessment of the pain control method ("excellent", "good", "fair", "poor"); patient satisfaction with the pain control level and the method of administration of pain medication (6-point scale: "extremely satisfied", "very satisfied", "satisfied", "dissatisfied", "very dissatisfied", "extremely dissatisfied"). Adverse drug reactions were recorded.Results: The SSTS reduced resting pain intensity in patients (n = 341) from a mean ± SD NRS score of 5.2 ± 2.3 (at SSTS handover) to 1.8 ± 1.6 (3rd day after handover). The proportion of patients with severe pain (for the PRO measure "most intense pain") decreased steadily during the 72 hours of treatment. Overall, 87.1% of the patients reported the method of pain control to be "good" or "excellent"; 91.8% reported being "extremely/very satisfied" or "satisfied" with the level of pain control; and 95.9% were at least satisfied with the method of pain medication administration. SSTS safety and tolerability was typical for opioids and as described in the SSTS Summary of Product Characteristics.Conclusions: The SSTS is a valuable option for real-life POPM and is effective in a wide range of surgical procedures.

[Considerations in ventilation of infants and children]. / Besonderheiten bei der Beatmung von Kindern.

The oxygen reserves of infants are low because of high oxygen demand in combination with low transport capacity. Respiratory adverse events are one of the major causes of morbidity and mortality during paediatric anaesthesia. During the last years our knowledge has grown substantially about the influence of artificial airways on the airway of paediatric patients. Modern anaesthetic concepts in infants and children include the use of cuffed tubes as well as a spontaneous breathing child.

Perioperative complications in infant cleft repair.

BACKGROUND: Cleft surgery in infants includes special risks due to the kind of the malformation. These risks can be attributed in part to the age and the weight of the patient. Whereas a lot of studies investigated the long-term facial outcome of cleft surgery depending on the age at operation, less is known about the complications arising during a cleft surgery in early infancy. METHODS: We investigated the incidence and severity of perioperative complications in 174 infants undergoing primary cleft surgery. The severity and the complications were recorded during the intraoperative and the early postoperative period according to the classification by Cohen. RESULTS: Our study revealed that minor complications occurred in 50 patients. Severe complications were observed during 13 operations. There was no fatal complication in the perioperative period. The risk of complications was found to be directly correlated to the body weight at the time of the surgery. Most of the problems appeared intraoperatively, but they were also followed by complications immediately after the extubation. CONCLUSION: In conclusion, cleft surgery in infancy is accompanied by frequent and sometimes severe perioperative complications that may be attributed to this special surgical field.

[Spinal regional anesthetic approaches in children: caudal block and spinal anesthesia]. / Rückenmarknahe Regionalanästhesieverfahren bei Kindern--Kaudalblock und Spinalanästhesie.

Caudal anesthesia is a safe, simple and very effective method to provide excellent perioperative analgesia. It is used routineously in pediatric anesthesia and can be applied to nearly all children with surgery below the umbilicus. In contrast, spinal anesthesia is a very special technique for former preterm infants below the 50th postconceptive week who are prone to develop postoperative apnea. It has been suggested that some of the problems associated with general anesthesia in these patients may be avoided by the use of spinal anesthesia.

Pharmacokinetics of intravenous paracetamol in children and adolescents under major surgery.

BACKGROUND: The aim of this study was to describe the pharmacokinetics of paracetamol (acetaminophen) and to get primary information on its metabolism after first indicated intravenous administration of paracetamol in children and adolescents undergoing major surgery. METHODS: About 4 weeks after the last chemotherapy, seven children and adolescents (five osteosarcoma, two Ewing tumors) received paracetamol infusion (median: 15.0 mg/kg) for analgesia. Sparse serum (37 samples; 4-7 per patient) and urine samples (27 samples; 0-15 per patient) were analyzed for paracetamol, paracetamol-glucuronide, paracetamol-sulfate, paracetamol-mercapturate and paracetamol-cysteine using capillary electrophoresis. Nonlinear mixed-effect models were used to describe the pharmacokinetics of paracetamol in plasma. RESULTS: Pharmacokinetics of paracetamol after intravenous administration was best described by a two-compartment model with clearance of 13.2 l/h per 70 kg (between-subject variability: 30%), intercompartmental clearance of 45.7 l/h per 70 kg (both parameters standardized to a 70-kg person using allometric "1/4 power models"), central volume of distribution of 13.2 l per 70 kg (between-subject variability: 71%) and peripheral volume of distribution of 33.0 l per 70 kg. Paracetamol, the glucuronide- and sulfate conjugates as well as cysteine and mercapturic acid conjugates, both products of oxidative pathways of paracetamol, were excreted in urine. CONCLUSIONS: Surgery, with all its potential influencing factors, together with chemotherapy given about 4 weeks previously do not seem to have a major impact on the pharmacokinetic behavior and the between-subject variability of paracetamol after intravenous administration.

Arteriovenous carboxyhemoglobin difference is not correlated to TNF-alpha, IL-6, PCT, CRP and leukocytes in critically ill patients.

BACKGROUND: It is still unclear as to whether the paradoxical arteriovenous carboxyhemoglobin (COHb) difference found in critical illness may represent a novel marker of the acute inflammatory response. We determined whether the arterial and central venous COHb concentration or their difference may be correlated to classical pro-inflammatory markers. METHODS: Arterial and matched central venous blood gases were obtained from non-smoking intensive care patients undergoing gastrointestinal surgery, and were correlated with plasma concentrations of tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), procalcitonin (PCT), C-reactive protein (CRP) and leukocytes. RESULTS: No correlation was found between arteriovenous COHb difference and the investigated pro-inflammatory mediators. While arterial and central venous COHb concentrations were positively correlated to plasma concentrations of TNF-alpha (P< or =0.01), IL-6 (P<0.05) and PCT (P< or =0.01), they were neither interrelated with PCT nor with leukocytes. CONCLUSIONS: Arteriovenous COHb difference does not appear to be a marker of the acute inflammatory response. Future studies are needed to investigate whether arterial and central venous COHb concentrations by themselves may serve as indicators of systemic inflammation.

Hepatitis after sevoflurane exposure in an infant suffering from primary hyperoxaluria type 1.

An 11-mo-old child with primary hyperoxaluria was scheduled for a nephroureteromia procedure. Anesthesia was induced and maintained with sevoflurane. Two days after the operation, a hepatomegaly was diagnosed, and a considerable increase in liver enzymes was observed. These pathologic findings disappeared without treatment within 7 days. In a subsequent operation 2 wk later, general anesthesia was performed (sevoflurane was avoided). After the second operation, no pathologic findings could be detected. Nothing in this patient's disease or the conduct of the anesthesia suggested a cause for the injury other than an idiosyncratic response to sevoflurane.

Delayed onset of malignant hyperthermia in desflurane anesthesia.

IMPLICATIONS: Animal-experimental studies demonstrate desflurane's trigger effect for malignant hyperthermia (MH). In contrast to other anesthetics, the time interval from exposure to the occurrence of symptoms is much longer with desflurane. This case report focuses on MH induced by desflurane alone.