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We have used the single space combined spinal-extradural technique for mothers requesting analgesia in labour. Intrathecal plain bupivacaine 5 mg produced a median time to analgesia of 3 min. There was inadequate abdominal analgesia after 10 min in 16% of recipients, although all had good perineal analgesia. The median height of block was T8 (range T4-L2) and mean duration of analgesia 72 (SD 21) min. Hypotension occurred in two of 30 mothers, but responded to fluids and ephedrine. There were no post-spinal headaches. This technique is suitable for those parturients requesting analgesia in active labour who may not have time to achieve extradural analgesia before delivery. The extradural catheter is used to improve analgesia if the subarachnoid block is inadequate, or if labour continues beyond the duration of the subarachnoid block.

SummaryA case is presented of a young woman with advanced cervical cancer invading the rectum and sacral nerves giving rise to an intractable pain state. The management of her symptoms using a domicillary infusion of diamorphine with high doses of ropivacaine is described. It is believed that this is the first presentation of ropivacaine being used in daily doses approaching 2 g, and the associated problems are discussed.

Jupiter's Trojan asteroids fulfill the prediction of Lagrange that orbits can be stable when a small body orbits in specific locations relative to its 'parent' planet and the Sun. The first such Trojan asteroid was discovered slightly over one hundred years ago, in 1906, and subsequently similar asteroids have been discovered associated with Mars and with Neptune. To date no Trojans have been discovered associated with Earth, but several horseshoe asteroids, co-orbital asteroids moving along a large range of the Earth's orbit, have been found. Other planets also are not known to have Trojan-type asteroids associated with them. Since the number of detected Jupiter Trojans has increased dramatically in the last few years, we have conducted a numerical survey of their orbital motions to see whether any in fact move in horseshoe orbits. We find that none do, but we use the enlarged database of information about Trojans to summarize their properties as now known, and compare these to results of theory.

SummaryAcute Physiology and Chronic Health Evaluation (APACHE) II scoring is widely used as an index of illness severity, for outcome prediction, in research protocols and to assess intensive care unit performance and quality of care. Despite its widespread use, little is known about the reliability and validity of APACHE II scores generated in everyday clinical practice. We retrospectively re-assessed APACHE II scores from the charts of 186 randomly selected patients admitted to our medical and surgical intensive care units. These`new' scores were compared with the original scores calculated by the attending physician. We found that most scores calculated retrospectively were lower than the original scores; 51% of our patients would have received a lower score, 26% a higher score and only 23% would have remained unchanged. Overall, the original scores changed by an average of 6.4 points. We identified various sources of error and concluded that wide variability exists in APACHE II scoring in everyday clinical practice, with the score being generally overestimated. Accurate use of the APACHE II scoring system requires adherence to strict guidelines and regular training of medical staff using the system. [4] are used widely in most intensive care units (ICUs). They are used not only as an index of illness severity and outcome prediction, but also to assess clinical performance and quality of care [5, 6]. The APACHE II score is the most frequently used scoring system and has become an important tool in efforts to improve effective use of intensive care [7±11]. In addition, it is often used in research protocols to ascertain that different treatment groups are comparable.Despite its widespread use in ICUs, little is known about the reliability and validity of the APACHE II scoring system in everyday medical practice. We reported that there was wide interobserver variation in the application of the APACHE II score when a group of doctors (residents and intensivists) assessed the same patient [12]. Chen et al.[13] studied interobserver variability and variability in data collection in a number of community and teaching hospitals; they reported that revised mortality predictions were similar to the original [13]. However, their study did not discuss in detail the specific sources of error and problems in APACHE II scoring.This study was designed to: (i) assess the accuracy of APACHE II scoring in a medical and surgical ICU; (ii) assess the influence of the method of data collection, manual or via a patient data management system (PDMS), on accuracy and overall variability in scoring; (iii) specifically identify and discuss sources of error and q 2001 Blackwell Science Ltd 47 confusion; and (iv) provide suggestions on how to decrease variability. MethodsThe charts of 64 patients admitted to the medical ICU and 122 patients admitted to the surgical ICU over a 6-month period were randomly selected. APACHE II scores are assessed routinely in all patients admitted to the ICU within 2 days of admission. In the medical ICU...

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By studying orbits of asteroids potentially in 3:2 exterior mean motion resonance with Earth, Venus, and Mars, we have found plutino analogs. We identify at least 27 objects in the inner solar system dynamically protected from encounter through this resonance. These are four objects associated with Venus, six with Earth, and seventeen with Mars. Bodies in the 3:2 exterior resonance (including those in the plutino resonance associated with Neptune) orbit the Sun twice for every three orbits of the associated planet, in such a way that with sufficiently low libration amplitude close approaches to the planet are impossible. As many as 15% of Kuiper Belt objects share the 3:2 resonance, but are poorly observed. One of several resonance sweeping mechanisms during planetary migration is likely needed to explain the origin and properties of 3:2 resonant Kuiper Belt objects. Such a mechanism likely did not operate in the inner solar system. We suggest that scattering by the next planet out allows entry to, and exit from, 3:2 resonance for objects associated with Venus or Earth. 3:2 resonators of Mars, on the other hand, do not cross the paths of other planets, and have a long lifetime. There may exist some objects trapped in the 3:2 Mars resonance which are primordial, with our tests on the most promising objects known to date indicating lifetimes of at least tens of millions of years. Identifying 3:2 resonant systems in the inner Solar System permits this resonance to be studied on shorter timescales and with better determined orbits than has been possible to date, and introduces new mechanisms for entry into the resonant configuration.