The link between acute postoperative pain and chronic pain syndromes

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Quantum quenches in a spinor condensate

We discuss the ordering of a spin-1 condensate when quenched from its paramagnetic phase to its ferromagnetic phase by reducing magnetic field. We first elucidate the nature of the equilibrium quantum phase transition. Quenching rapidly through this transition reveals XY ordering either at a specific wavevector, or the `light-cone' correlations familiar from relativistic theories, depending on the endpoint of the quench. For a quench proceeding at a finite rate the ordering scale is governed by the Kibble-Zurek mechanism. The creation of vortices through growth of the magnetization fluctuations is also discussed. The long time dynamics again depends on the endpoint, conserving the order parameter in zero field, but not at finite field, with differing exponents for the coarsening of magnetic order. The results are discussed in the light of a recent experiment by Sadler \emph{et al.}Comment: Published versio

Guest Editorial: South African guidelines for the treatment of cancer pain: South African Cancer Pain Guidelines Working Group

No Abstract

The prevalence of skin scars in patients previously given intramuscular diclofenac injections attending the Pain Clinic at Universitas Academic Hospital, Bloemfontein, South Africa

Intramuscular (IM) diclofenac rarely causes scarring (reported incidence <0.05%). Some patients attending the Pain Clinic at Universitas Academic Hospital, Bloemfontein, South Africa, presented with scars that had developed after IM diclofenac injections. We investigated the prevalence of scars in patients at the clinic and how the injections had been obtained. Patients attending the clinic over a period of 9 months who said they had received diclofenac (N=131) were included. Information was collected using a questionnaire and physical examination. Data obtained from 118 patients who were certain that they had received diclofenac were analysed. Ninety-three patients (78.8%) indicated they had not been warned about the possibility that a diclofenac injection could result in scarring. Scarring had occurred in 10 patients (8.5%). Two-thirds of the patients who had obtained diclofenac from a pharmacy had never had a prescription for it. Four patients had required medical treatment for an ulcer or abscess, of whom two had undergone surgery. The risk of skin lesions associated with IM diclofenac is higher than reported previously. Contrary to regulations, diclofenac injections were often dispensed to patients without a prescription

Intravenous paracetamol — waste not, want not: a retrospective audit on the appropriate use of intravenous paracetamol at Universitas Academic Hospital Complex—Bloemfontein

Background: Paracetamol can be given both orally and intravenously (IV) with similar clinical efficacy, but the IV formulation is 360 times more expensive. IV paracetamol is therefore only recommended when the oral route is not available. This study investigated whether IV paracetamol was being used appropriately and whether there had been a change in prescribing patterns between 2008 and 2015 after the introduction and update of a prescribing protocol at an academic hospital complex in Bloemfontein, South Africa.Methods: A retrospective comparative audit of patient files was undertaken. The prescribing and administration habits of IV paracetamol were compared for two consecutive months, seven years apart, including 88 and 83 patients, respectively, who had received IV paracetamol.Results: IV paracetamol was administered appropriately in 37.5% of patients in 2008 and in 43.4% of patients in 2015 (p = 0.43). There was an improvement in the duration that IV paracetamol was prescribed for, which decreased from a median two days in 2008 to one day (p < 0.01) in 2015. In total, 55 (32.4%) patients had a concomitant oral and IV paracetamol prescription, of which 37 (21.6%) patients also received concomitant paracetamol administration. Twenty patients exceeded the 24-hour maximum dose. Seventeen patients weighed less than 40 kg; six of these patients (three paediatric and three adult) did not receive the correct weight adjusted dose of paracetamol, 15 mg/kg, resulting in excessive doses of paracetamol being administered (21– 32.3 mg/kg).Conclusions: Patients are receiving IV paracetamol when the oral route is available; this is an unnecessary waste of money. Excessive doses of paracetamol were administered due to concomitant oral and IV paracetamol prescription and administration, and a failure to calculate dose of paracetamol according to body weight in low body weight patients. Further remedial interventions are therefore required.Keywords: acetaminophen, analgesia, appropriate, audit, intravenous, pain, paracetamol, pyrexi

A survey of nurses’ basic life support knowledge and training at a tertiary hospital

Objective: Survival after cardiac arrest is related to time taken for resuscitation, and defibrillation, to commence. At many hospitals, the healthcare worker most likely to be present when a patient suffers a cardiac arrest is a nurse. This study was performed to assess BLS knowledge and training of nurses, and thus to determine whether further action is required to improve their BLS competency. Method: The study was a cross-sectional survey. A questionnaire was distributed, on one day, to nurses in the wards, out-patient-departments and theatres. Completion of the form was voluntary and confidential. The forms were all returned that day. Results: Questionnaires were completed by 338 of the 405 nursing personnel on duty that day (83.4% response rate). Administrators and student nurses were excluded as well as incomplete questionnaires , leaving a final sample size of 286 nurses. A pass mark of 80% was achieved by 11% of responders. Training in BLS had been available for 77.5% of nurses and of these 93.1% had attended a course, 60.9% within the last year. Training in the use of a defibrillator had not been received by 32% of nurses and there was generally a poor understanding of the significance of defibrillation in resuscitation. Conclusion: Despite a relatively good rate of attendance at recent BLS courses, over a fifth of nurses remain without any BLS training. In addition few nurses have retained the BLS knowledge required for competency. Action is needed to ensure all nurses receive BLS training and practice this skill regularly

Weak Coulomb blockade effect in quantum dots

We develop the general non-equilibrium theory of transport through a quantum dot, including Coulomb Blockade effects via a 1/N expansion, where N is the number of scattering channels. At lowest order we recover the Landauer formula for the current plus a self-consistent equation for the dot potential. We obtain the leading corrections and compare with earlier approaches. Finally, we show that to leading and next leading order in 1/N there is no interaction correction to the weak localization, in contrast to previous theories, but consistent with experiments by Huibers et al. [Phys. Rev. Lett. 81, 1917 (1998)], where N=4.Comment: 4 pages, 2 figures. Published versio

Training and experience of doctors administering obstetric anaesthesia in the Free State Level 1 and 2 Hospitals

Background All the published Saving Mothers Reports generated by the National Committee of the Confidential Enquiries into MaternalDeaths in South Africa have associated anaesthesia-related maternal deaths with the lack of skills of the doctors administering the anaesthesia. The Reports have shown the Free State to be one of the provinces in South Africa with the highest rate of obstetric anaesthesia deaths. Therefore, the current study was performed to determine whether a deficiency exists in the training and experience of doctors administering obstetric anaesthesia. The identifying of such a deficiency would call for the implementation of remedial measures.Methods The study was performed in 2005 using questionnaires designed by the first two authors of this paper. All Level 1 and 2hospitals in the Free State performing Caesarean sections (CSs) were visited. The doctors administering obstetric anaesthesia were each asked to respond to a questionnaire. The questionnaires enquired about previous training and experience in anaesthesia and, more specifically, obstetric anaesthesia, as well as anaesthesia and nonanaesthesia qualifications. In addition, questions were asked regarding supervision, and whether other duties were performed while administering anaesthesia. Results The response rate was 69% (105/148 doctors). Of the respondents, 9.5% were interns, 24.7% community service doctors, 47.6% medical officers, 15.2% general practitioners (GPs) and 2.9% specialists. Twenty-three per cent of respondents had been in their present post for five years or more. Most doctors had received 4 weeks or less training in anaesthesia as an Intern, not including obstetric anaesthesia in 13 cases. Six doctors (GPs or medical officers) had been appointed in posts in which obstetric anaesthesia was required, without previously having administered obstetric anaesthesia. At the time of the survey, two doctors had never performed spinal anaesthesia and five had never administered general anaesthesia for CS, although all were regularly administering obstetric anaesthesia. Apart from the specialists, the Diploma in Anaesthesia was held by only one doctor, a medical officer. Half of the interns were not directly supervised while administering obstetric anaesthesia, while more than half the community service doctors were employed in hospitals where no senior support wasavailable. The doctors frequently had both to administer the anaesthetic and to perform neonatal resuscitation. Twelve ofthe doctors concerned had often also to perform the surgery itself. Most of the doctors requested further training in obstetricanaesthesia and improved senior anaesthetic assistance.Conclusions There is a lack of experience, training and supervision amongst doctors administering obstetric anaesthesia in the Free State.Doctors regularly have to perform other duties, whilst administering obstetric anaesthesia, which may put the mother atrisk from inadequate observation. These may be contributory factors to the high rate of maternal deaths from anaesthesia

Long wavelength spin dynamics of ferromagnetic condensates

We obtain the equations of motion for a ferromagnetic Bose condensate of arbitrary spin in the long wavelength limit. We find that the magnetization of the condensate is described by a non-trivial modification of the Landau-Lifshitz equation, in which the magnetization is advected by the superfluid velocity. This hydrodynamic description, valid when the condensate wavefunction varies on scales much longer than either the density or spin healing lengths, is physically more transparent than the corresponding time-dependent Gross-Pitaevskii equation. We discuss the conservation laws of the theory and its application to the analysis of the stability of magnetic helices and Larmor precession. Precessional instabilities in particular provide a novel physical signature of dipolar forces. Finally, we discuss the anisotropic spin wave instability observed in the recent experiment of Vengalattore et. al. (Phys. Rev. Lett. 100, 170403, (2008)).Comment: arXiv version contains additional Section V relevant to the experiment of Vengalattore et. al. (Phys. Rev. Lett. 100, 170403, (2008)