Paracetamol (acetaminophen) pack size restrictions and poisoning severity: time trends in enquiries to a UK poisons centre

BACKGROUND AND OBJECTIVE

In September 1998, legislation was introduced in the United Kingdom to limit paracetamol pack sizes to 16 tablets of 500 mg at general sales outlets and 32 tablets of 500 mg at pharmacies. The effect of the regulations on severity of paracetamol poisoning is unclear. The aim of this study was to describe trends in the severity of paracetamol poisoning and to assess the impact of the 1998 Regulations on the enquiries to a UK poisons centre.

METHODS

We extracted data about the age, sex and number of tablets or capsules of paracetamol ingested by patients notified to Guy's and St Thomas' Poisons Unit (London, UK) between 1996 and 2004.

RESULTS AND DISCUSSION

During the study period, there were approximately 140 000 patients with suspected paracetamol poisoning, accounting for around 11% of all patients reported to the poisons unit. The median number of tablets fell from 25 to 20 for males and 20 to 16 for females after 1998. There was also a reduction in the proportion of patients who ingested 17-32 tablets (from 36% to 30%) and 33-100 tablets (from 25% to 19%).

CONCLUSION

Following the 1998 Regulations there was a decline in the severity, but not frequency, of paracetamol poisoning cases reported to Guy's and St Thomas' Poisons Unit. It is unclear whether the decline in severity was a direct consequence of the regulations.

Queensland psychiatrists' attitudes and perceptions of adults with intellectual disability

BACKGROUND

Quality mental health care for adults with an intellectual disability (ID) depends upon the availability of appropriately trained and experienced psychiatrists. There have been few surveys of psychiatrists working with this population.

METHOD

This Australian study obtained psychiatrists' attitudes to and perceptions of the mental health needs of adults with an ID. Training needs were also sought. The survey instrument used was a purposely designed, 28-item self-administered questionnaire featuring multiple-choice and open-ended questions.

RESULTS

The majority of psychiatrists expressed concerns about treatment of this group, describing unmet needs. A total of 75% considered that antipsychotics were overused to control aggression, and 34% of psychiatrists were reluctant to treat adults with an ID. In total, 85% agreed that mental health in ID should be offered as a training option for psychiatric registrars, and that specialized mental health services would provide a high standard of care for this population.

CONCLUSION

Broad concerns are raised regarding pathways to mental health care for adults with an ID in Australia. An Australia-wide training strategy needs to be developed. Partnerships between mental health, disability and community services that serve the mental health needs of this population, should actively seek to engage psychiatrists.

Proteomic strategies for rapid characterization of micro-organisms

Bioinformatic considerations are offered to illustrate strengths and limitations of the characterization of Bacillus spores based on proteomic interpretation of matrix-assisted laser desorption/ionization spectra. In particular, species-specific biomarkers are evaluated in the context of both experimental access and uniqueness in silico.

The role of livestock in the management of dryland salinity

Management of dryland salinity in Australia will require changes in the design and utilisation of plant systems in agriculture. These changes will provide new opportunities for livestock agriculture. In areas already affected by salt, a range of plants can be grown from high feeding value legumes with moderate salt tolerance through to highly salt tolerant shrubs. A hectare of these plants may support between 500 and 2000 sheep grazing days per year. The type of plants that can be grown and the subsequent animal production potential depend on a range of factors that contribute to the ‘salinity stress index’ of a site, including soil and groundwater salinity, the extent and duration of waterlogging and inundation, the pattern and quantity of annual rainfall, soil texture and chemistry, site topography and other site parameters. Where the salinity stress index is high, plant options will usually include a halophytic shrub that accumulates salt. High salt intakes by grazing ruminants depress feed intake and production. Where high and low salt feeds are available together, ruminants will endeavour to select a diet that optimises the overall feeding value of the ingested diet. In areas that are not yet salt affected but contribute to groundwater recharge, perennial pasture species offer an opportunity for improved water and salt management both on-farm and at the catchments. If perennial pasture systems are to be adopted on a broad scale, they will need to be more profitable than current annual systems. In the high rainfall zones in Victoria and Western Australia, integrated bioeconomic and hydrological modelling indicates that selection of perennial pasture plants to match requirements of a highly productive livestock system significantly improves farm profit and reduces groundwater recharge. In the low to medium rainfall zones, fewer perennial plant options are available. However, studies aiming to use a palette of plant species that collectively provide resilience to the environment while maintaining profitable livestock production may also lead to new options for livestock in the traditional cropping zone.

Home-like versus conventional institutional settings for birth

BACKGROUND

Home-like birth settings have been established in or near conventional labour wards for the care of pregnant women who prefer and require little or no medical intervention during labour and birth.

OBJECTIVES

Primary: to assess the effects of care in a home-like birth environment compared to care in a conventional labour ward. Secondary: to determine if the effects of birth settings are influenced by staffing or organizational models or geographical location of the birth centre.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group trials register (18 May 2004) and handsearched eight journals and two published conference proceedings.

SELECTION CRITERIA

All randomized or quasi-randomized controlled trials that compared the effects of a home-like institutional birth environment to conventional hospital care.

DATA COLLECTION AND ANALYSIS

Standard methods of the Cochrane Collaboration Pregnancy and Childbirth Group were used. Two review authors evaluated methodological quality. Double data entry was performed. Results are presented using relative risks and 95% confidence intervals.

MAIN RESULTS

Six trials involving 8677 women were included. No trials of freestanding birth centres were found. Between 29% and 67% of women allocated to home-like settings were transferred to standard care before or during labour. Allocation to a home-like setting significantly increased the likelihood of: no intrapartum analgesia/anaesthesia (four trials; n = 6703; relative risk (RR) 1.19, 95% confidence interval (CI) 1.01 to 1.40), spontaneous vaginal birth (five trials; n = 8529; RR 1.03, 95% CI 1.01 to 1.06), vaginal/perineal tears (four trials; n = 8415; RR 1.08, 95% CI 1.03 to 1.13), preference for the same setting the next time (one trial; n = 1230; RR 1.81, 95% CI 1.65 to 1.98), satisfaction with intrapartum care (one trial; n = 2844; RR 1.14, 95% CI 1.07 to 1.21), and breastfeeding initiation (two trials; n = 1431; RR 1.05, 95% CI 1.02 to 1.09) and continuation to six to eight weeks (two trials; n = 1431; RR 1.06, 95% CI 1.02 to 1.10). Allocation to a home-like setting decreased the likelihood of episiotomy (five trials; n = 8529; RR 0.85, 95% CI 0.74 to 0.99). There was a trend towards higher perinatal mortality in the home-like setting (five trials; n = 8529; RR 1.83, 95% CI 0.99 to 3.38). No firm conclusions could be drawn regarding the effects of staffing or organizational models.

AUTHORS' CONCLUSIONS

When compared to conventional institutional settings, home-like settings for childbirth are associated with modest benefits, including reduced medical interventions and increased maternal satisfaction. Caregivers and clients should be vigilant for signs of complications.

Unconscious auditory priming during surgery with propofol and nitrous oxide anaesthesia: a replication

BACKGROUND

Priming during anaesthesia has been hard to replicate and the conditions under which it occurs remain poorly understood. We replicated and extended a recent study to determine whether intraoperative priming during propofol and nitrous oxide anaesthesia is a reliable phenomenon, whether it occurs due to awareness during word presentation and whether it is suppressed by a dose of fentanyl at induction.

METHODS

Words were played through headphones during surgery to 62 patients receiving propofol and nitrous oxide anaesthesia. Thirty-two patients received fentanyl 1.5 microg kg(-1) at induction and 30 received no fentanyl. Neuromuscular blocking drugs were not used. Depth of anaesthesia was measured using the bispectral index (BIS). Anaesthetic variables were recorded at 1 min intervals during word presentation. On recovery, implicit and explicit memory were assessed using an auditory word-stem completion test and a yes-no word-recognition test, respectively.

RESULTS

BIS, blood pressure, end-tidal carbon dioxide and heart rate during word presentation did not differ between the study groups. The infusion rate of propofol and the patients' ventilatory frequency were significantly higher in the group not receiving fentanyl. No patient had unprompted explicit recall of surgery, although there was above-zero performance in six patients on the yes-no recognition task (P<0.05). There was no physiological evidence of awareness during anaesthesia (median mean-BIS=38 in the no-fentanyl group and 42 in the fentanyl group). There was evidence for priming (mean priming score=0.09, P<0.05 in the no-fentanyl study group; mean priming score=0.07, P<0.05 in the fentanyl group) even when patients with momentary light anaesthesia (maximum recorded BIS> or =60) and/or positive recognition scores were excluded from the analysis.

CONCLUSIONS

Existing knowledge can be primed by information presented during propofol and nitrous oxide anaesthesia. This priming is evidence of unconscious information processing and not the result of moments of awareness.

Inter-rater agreement in defining chemical incidents at the National Poisons Information Service, London

BACKGROUND

National surveillance for chemical incidents is being developed in the UK. It is important to improve the quality of information collected, standardise techniques, and train personnel.

OBJECTIVE

To define the extent to which eight National Poison Information Service specialists in poison information agree on the classification of calls received as "chemical incidents" based on the national definition.

DESIGN

Blinded, inter-rater reliability measured using the kappa statistic for multiple raters.

SETTING

National Poison Information Service and Chemical Incident Response Service, Guy's and St Thomas's NHS Trust, London.

PARTICIPANTS

Eight specialists in poison information who are trained and experienced in handling poisons information calls and have been involved in extracting information for surveillance.

RESULTS

The overall level of agreement observed was at least 69% greater than expected by chance (kappa statistic). Fire and incidents where chemicals were released within a property had a very good level of agreement with kappa statistic of 83% and 80% respectively. The lowest level of agreement was observed when no one or only one person was exposed to a chemical (33%) and when the chemical was released into the air (48%).

CONCLUSION

High levels of agreement were observed. There is a need for more training and improvement in consistency of the data collected by all organisations.

Unconscious learning during surgery with propofol anaesthesia † †This article is accompanied by Editorial II

BACKGROUND

Learning during anaesthesia has been demonstrated, but little is known about the circumstances under which it may occur. This study investigated the hypothesis that learning during anaesthesia occurs during, but not before, surgical stimulation.

METHODS

Words were played through headphones to 64 day-surgery patients during propofol anaesthesia. Fourteen words were played repeatedly (15 times) for 1 min each either before (n=32) or during (n=32) surgical stimulation. The depth of anaesthesia was estimated using the bispectral index (BIS). Heart rate, ventilatory frequency, mean arterial pressure, end-tidal carbon dioxide concentration, and infusion rate of propofol were recorded at 1 min intervals during word presentation. On recovery, memory was assessed using an auditory word stem completion test and word recognition test.

RESULTS

The mean BIS, arterial pressure, end-tidal carbon dioxide and heart rate during word presentation did not differ between the groups. The infusion rate of propofol and the ventilatory frequency were significantly greater in the during-surgical stimulation group. There was no evidence for explicit recall or recognition, nor of awareness during anaesthesia (median mean-BIS=38 in the before-surgical stimulation group and 42 in the during-surgical stimulation group). Only patients who were played words during surgical stimulation showed significant implicit memory on recovery (mean score=0.08, P<0.02) However, their scores were not significantly higher than those of the before-surgical stimulation group (mean score=0.01).

CONCLUSIONS

Learning during anaesthesia seems more likely to occur during rather than before surgical stimulation at comparable anaesthetic depth. We hypothesize that surgical stimulation facilitates learning during anaesthesia, independently of its effects on anaesthetic depth.

Doctors and managers: poor relationships may be damaging patients-what can be done?

The problem of poor relationships between doctors and managers is a common feature of many healthcare systems. This problem needs to be explicitly addressed and there are a number of positive steps that could be taken. Firstly, there would be value in working to improve the quality of relationships and better mutual understanding of the necessarily different positions of doctors and managers. Finding a common approach to managing resources, accountability, autonomy, and the creation of more systematic ways of working seems to be important. The use of costed clinical pathways may be one approach. Rather than seeing guidelines and accountability systems as a threat to autonomy there is an argument that they are an essential adjunct to it. Redefining autonomy in order to preserve it and to ensure that it encompasses accountability and responsibility will be an important step. A key step is the development of clinical leadership.

Oral antioxidant supplementation for fatigue associated with primary biliary cirrhosis: results of a multicentre, randomized, placebo-controlled, cross-over trial

BACKGROUND

We have previously reported, in an uncontrolled trial, an improvement in fatigue scores in patients with primary biliary cirrhosis given oral antioxidant supplementation. We now present data from a controlled trial.

PATIENTS AND METHODS

Sixty-one patients with primary biliary cirrhosis-associated fatigue were randomized into a double-blind, placebo-controlled, cross-over trial. Participants received 12 weeks each of placebo and antioxidant supplementation (vitamins A, C and E, selenium, methionine and ubiquinone) in random order, separated by a 4-week washout period. The primary trial outcome (fatigue) was assessed using the Fisk scale. Other symptoms of primary biliary cirrhosis were measured using Likert and visual analogue scales.

RESULTS

Forty-four patients completed both arms of the trial. No significant changes in fatigue were recorded in the active phase of treatment (median improvement in Fisk score, 1; P = 0.61). Small improvements in Fisk scores were recorded during placebo therapy (median improvement, 4; P = 0.03). Neither medication was associated with improvement in any other symptoms related to primary biliary cirrhosis. Adverse effects were more common during active therapy and were mild and self-limiting. One patient died from unrelated causes during active treatment.

CONCLUSIONS

Although oral antioxidant supplementation appears to be safe, we could not find any evidence for a beneficial effect on fatigue or other liver-related symptoms.

Lactation is associated with an increase in slow-wave sleep in women

Major physiological changes occur following parturition and the onset of lactation, including the withdrawal of oestrogen and progesterone, with a consequent increase in circulating prolactin (PRL). Changes in other circulating hormones are well known to alter sleep architecture in other circumstances. We therefore aimed to assess whether sleep architecture is altered in fully lactating women as a result of hormonal changes associated with lactation. A descriptive comparison study was undertaken on 12 fully breastfeeding women (B/F), 12 age-matched control women (CTRL), and seven postnatal women who had chosen to bottle-feed their infants (BOTTLE). Maternal age, infant age and body mass index (BMI) were similar between all three groups. We performed overnight polysomnography utilizing the Portable Compumedics P-series. The total sleep time (TST) and rapid eye movement (REM) sleep time were similar in the three groups of women. However, B/F women demonstrated a marked increase in slow wave sleep (SWS), 182 +/- 41 min compared with CTRL (86 +/- 22 min, P < 0.001 compared with B/F) and BOTTLE subjects (63 +/- 29 min, P < 0.001 compared with B/F). There was a compensatory reduction in light non-rapid eye movement (NREM) sleep in B/F when compared with CTRL and BOTTLE. The most likely explanation for the altered sleep architecture noted to occur in women who are fully breastfeeding their infants is an increase in circulating PRL, which occurs in lactating women. Enhanced SWS may be another important factor to support breastfeeding in the postnatal period.

Sleep disordered breathing and pregnancy

Many changes in the respiratory system occur during pregnancy, particularly during the third trimester, which can alter respiratory function during sleep, increasing the incidence and severity of sleep disordered breathing. These changes include increased ventilatory drive and metabolic rate, reduced functional residual capacity and residual volume, increased alveolar-arterial oxygen gradients, and changes in upper airway patency. The clinical importance of these changes is indicated by the increased incidence of snoring during pregnancy, which is likely also to reflect an increased incidence of obstructive sleep apnoea/hypopnoea syndrome. For the respiratory physician asked to review a pregnant patient, the possibility of sleep disordered breathing should always be considered. This review first examines the normal physiological changes of pregnancy and their relationship to sleep disordered breathing, and then summarises the current knowledge of sleep disordered breathing in pregnancy.

SCOPE: a probabilistic model for scoring tandem mass spectra against a peptide database

Proteomics, or the direct analysis of the expressed protein components of a cell, is critical to our understanding of cellular biological processes in normal and diseased tissue. A key requirement for its success is the ability to identify proteins in complex mixtures. Recent technological advances in tandem mass spectrometry has made it the method of choice for high-throughput identification of proteins. Unfortunately, the software for unambiguously identifying peptide sequences has not kept pace with the recent hardware improvements in mass spectrometry instruments. Critical for reliable high-throughput protein identification, scoring functions evaluate the quality of a match between experimental spectra and a database peptide. Current scoring function technology relies heavily on ad-hoc parameterization and manual curation by experienced mass spectrometrists. In this work, we propose a two-stage stochastic model for the observed MS/MS spectrum, given a peptide. Our model explicitly incorporates fragment ion probabilities, noisy spectra, and instrument measurement error. We describe how to compute this probability based score efficiently, using a dynamic programming technique. A prototype implementation demonstrates the effectiveness of the model.

Hemodynamic responses to obstructive respiratory events during sleep are augmented in women with preeclampsia

Preeclampsia is the most common disease of pregnancy, occurring in up to 10% of the pregnant population. The cause of the disease is as yet undetermined; however, most of the clinical effects are commonly attributed to damage to the endothelial layer, leading to increased pressor activity of all the maternal blood vessels. Therefore, we suspected that if obstructive sleep apnea (OSA) coexisted with preeclampsia in pregnancy, the hemodynamic effects of the OSA would be markedly potentiated. To test this hypothesis, we performed full sleep studies and overnight beat-to-beat blood pressure (BP) monitoring. The control patient group included 10 pregnant women with OSA and no evidence of hypertensive disease either before or during their current pregnancy. The test group included 10 women with preeclampsia and coexisting OSA. The pressor responses to obstructive respiratory events during sleep were enhanced in preeclamptic patients compared with control OSA patients (21+/-2/12+/-1 mm Hg and 38+/-5/25+/-4 mm Hg above baseline in control OSA and preeclamptic OSA patients, respectively, P = .005/.005). In contrast, there was no difference in heart rate responses between the two groups of subjects (34+/-5 beats/min and 49+/-13 beats/min above baseline in control and preeclamptic patient groups, respectively, P = .326). We suggest that the augmented pressor responses in preeclamptic women occur as a result of maternal endothelial damage induced by the preeclampsia disease process. These findings may have important implications in the management of preeclamptic patients.