Emergency medicine: A practice prone to error?

The last decade has witnessed a rapidly growing public and academic interest in medical error, an interest that has culminated in the emergence of the science of error prevention in health care. The impact of this new science will be felt in all areas of medicine but perhaps especially in emergency medicine (EM). The emergency department’s unique operating characteristics make it a natural laboratory for the study of error. These characteristics, combined with the complex and myriad activities of EM, predict vulnerability to a multitude of errors. Overcrowding and other resource limitations impair continuous quality improvement, and many errors result from high decision density, excessive cognitive load and flawed thinking in the decision-making process. A large proportion of these errors have serious outcomes but an even higher proportion are preventable.

The historical practice of blaming individuals for errors needs to be replaced by root-cause analysis that identifies process and systemic weaknesses. Quantitative and qualitative methods are needed to detect, describe and classify error at all levels in the system. Research is needed into the processes that underlie EM error. Educational initiatives should be developed at all levels, for everyone from undergraduate trainees to practicing emergency physicians. Changes in societal attitudes will be an important component of the new culture of patient safety.

A nationwide reporting system is proposed to disseminate error information expediently. Canadian EM providers are in a pivotal position to provide leadership to the Canadian health care system in this important area.

Measurement of the rate of nu(e) + d --> p + p + e(-) interactions produced by (8)B solar neutrinos at the Sudbury Neutrino Observatory

Solar neutrinos from (8)B decay have been detected at the Sudbury Neutrino Observatory via the charged current (CC) reaction on deuterium and the elastic scattering (ES) of electrons. The flux of nu(e)'s is measured by the CC reaction rate to be straight phi(CC)(nu(e)) = 1.75 +/- 0.07(stat)(+0.12)(-0.11)(syst) +/- 0.05(theor) x 10(6) cm(-2) s(-1). Comparison of straight phi(CC)(nu(e)) to the Super-Kamiokande Collaboration's precision value of the flux inferred from the ES reaction yields a 3.3 sigma difference, assuming the systematic uncertainties are normally distributed, providing evidence of an active non- nu(e) component in the solar flux. The total flux of active 8B neutrinos is determined to be 5.44+/-0.99 x 10(6) cm(-2) s(-1).

Markers of inflammation and stress distinguish subsets of individuals with schizophrenia and bipolar disorder

Schizophrenia and bipolar disorder share a number of common features, both symptomatically and biologically. Abnormalities in the neuroimmune and the stress-signaling pathways have been previously identified in brains of individuals with both diseases. However, the possible relationship between abnormalities in stress and neuroimmune signaling within the cortex of people with psychotic illness has not been defined. To test the hypothesis that combined alterations in brain stress responsiveness and neuroimmune/inflammatory status are characteristic of some individuals suffering from major mental illness, we examined gene expression in the Stanley Array Cohort of 35 controls, 35 individuals with schizophrenia and 34 individuals with bipolar disorder. We used levels of 8 inflammatory-related transcripts, of which SERPINA3 was significantly elevated in individuals with schizophrenia (F(2,88)=4.137, P<0.05), and 12 glucocorticoid receptor signaling (stress) pathway transcripts previously examined, to identify two clusters of individuals: a high inflammation/stress group (n=32) and a low (n=68) inflammation/stress group. The high inflammation/stress group has a significantly greater number of individuals with schizophrenia (n=15), and a trend toward having more bipolar disorder individuals (n=11), when compared with controls (n=6). Using these subgroups, we tested which microarray-assessed transcriptional changes may be associated with high inflammatory/stress groups using ingenuity analysis and found that an extended network of gene expression changes involving immune, growth factors, inhibitory signaling and cell death factors also distinguished these groups. Our work demonstrates that some of the heterogeneity in schizophrenia and bipolar disorder may be partially explained by inflammation/stress interactions, and that this biological subtype cuts across Diagnostic and Statistical Manual of Mental Disorders (DSM)-defined categories.

Direct evidence for neutrino flavor transformation from neutral-current interactions in the Sudbury Neutrino Observatory

Observations of neutral-current nu interactions on deuterium in the Sudbury Neutrino Observatory are reported. Using the neutral current (NC), elastic scattering, and charged current reactions and assuming the standard 8B shape, the nu(e) component of the 8B solar flux is phis(e) = 1.76(+0.05)(-0.05)(stat)(+0.09)(-0.09)(syst) x 10(6) cm(-2) s(-1) for a kinetic energy threshold of 5 MeV. The non-nu(e) component is phi(mu)(tau) = 3.41(+0.45)(-0.45)(stat)(+0.48)(-0.45)(syst) x 10(6) cm(-2) s(-1), 5.3sigma greater than zero, providing strong evidence for solar nu(e) flavor transformation. The total flux measured with the NC reaction is phi(NC) = 5.09(+0.44)(-0.43)(stat)(+0.46)(-0.43)(syst) x 10(6) cm(-2) s(-1), consistent with solar models.

Effects of postnatal depression on children's adjustment to school. Teacher's reports

BACKGROUND

Little is known of the behavioural adjustment of children of postnatally depressed mothers. Previous studies have relied on maternal reports, and have produced inconsistent findings.

METHOD

In a prospective, longitudinal study of the five-year-old children of a community sample of postnatally depressed and well women, evidence was collected concerning the children's adjustment in the context of school, teachers being asked to complete questionnaires after the children had finished their first term.

RESULTS

Family social class and the child's gender had the most pervasive influences on adjustment. However, both postnatal and recent maternal depression were associated with significantly raised levels of child disturbance, particularly among boys and those from lower social class families.

CONCLUSIONS

The findings indicate a persistent effect of postnatal depression on child adjustment. They highlight the need for resources devoted to supporting mothers of young children and particularly routine screening and treatment for postnatal mood disorder.

Campylobacteriosis in New Zealand: results of a case-control study

STUDY OBJECTIVE

To identify and assess the contributions of major risk factors for campylobacteriosis in New Zealand.

DESIGN

Case-control study. Home interviews were conducted over nine months using a standardised questionnaire to assess recent food consumption and other exposures.

SETTING

Four centres in New Zealand with high notification rates of campylobacter infections--Auckland, Hamilton, Wellington, and Christchurch.

PARTICIPANTS

Case patients were 621 people notified between 1 June 1994 and 28 February 1995 as having campylobacter infection. Control subjects were selected randomly from telephone directories, and were matched 1:1 with case patients in relation to sex, age group, and home telephone prefix.

RESULTS

Risk of campylobacteriosis was strongly associated with recent consumption of raw or undercooked chicken (matched odds ratio 4.52, 95% confidence interval 2.88, 7.10). There was also an increased risk with chicken eaten in restaurants (matched odds ratio 3.85; 2.52, 5.88). Recent consumption of baked or roasted chicken seemed to be protective. Campylobacteriosis was also associated with recent overseas travel, rainwater as a source of water at home, consumption of raw dairy products, and contact with puppies and cattle, particularly calves.

CONCLUSIONS

Improperly cooked chicken seems to be associated with a large proportion of campylobacteriosis in New Zealand. Thorough cooking of chicken in homes and restaurants could reduce considerably the incidence of this disease.

Aging in Saccharomyces cerevisiae

The budding yeast Saccharomyces cerevisiae divides asymmetrically, giving rise to a mother cell and a smaller daughter cell. Individual mother cells produce a finite number of daughter cells before senescing, undergoing characteristic changes as they age such as a slower cell cycle and sterility. The average life span is fixed for a given strain, implying that yeast aging has a strong genetic component. Genes that determine yeast longevity have highlighted the importance of such processes as cAMP metabolism, epigenetic silencing, and genome stability. The recent finding that yeast aging is caused, in part, by the accumulation of circular rDNA molecules has unified many seemingly disparate observations.

Behavioral dimensions of adjustment in persons with chronic pain: pain-related anxiety and acceptance

Through empirical methods we now characterize patients with chronic pain as either dysfunctional, interpersonally distressed, or adaptive copers. Studying factors that differentiate these groups may reveal the behavioral processes that determine adjustment to pain. Subjects for this study were 190 patients referred for treatment of chronic pain. They were classified as dysfunctional (n = 41), interpersonally distressed (n = 28) or adaptive copers (n = 59) based on the Multidimensional Pain Inventory (Kerns, R.D., Turk, D.C. and Rudy, T.E., The West Haven-Yale Multidimensional Pain Inventory (WHYMPI), Pain, 23 (1985) 345-356) and compared on measures of pain-related anxiety and pain acceptance. Our analyses showed that the dysfunctional group reported greater pain-related anxiety and less acceptance of pain than the other groups. Additional analyses, statistically controlling for pain severity and depression, showed that the patient subtypes continued to differ on pain-related anxiety and acceptance. Discriminant function analyses including pain-related anxiety and acceptance correctly classified 72.5% of dysfunctional and 90.9% of adaptive copers. Again, anxiety and acceptance contributed uniquely to classification independent of depression and pain intensity. Pain-related anxiety and acceptance of pain appear to be unique behavioral dimensions of adjustment to chronic pain. Decreasing anxiety and increasing acceptance may 'move' patients with chronic pain from the dysfunctional to the adaptive coper category.

Sensory processing in autism spectrum disorders and Fragile X syndrome-From the clinic to animal models

Brains are constantly flooded with sensory information that needs to be filtered at the pre-attentional level and integrated into endogenous activity in order to allow for detection of salient information and an appropriate behavioral response. People with Autism Spectrum Disorder (ASD) or Fragile X Syndrome (FXS) are often over- or under-reactive to stimulation, leading to a wide range of behavioral symptoms. This altered sensitivity may be caused by disrupted sensory processing, signal integration and/or gating, and is often being neglected. Here, we review translational experimental approaches that are used to investigate sensory processing in humans with ASD and FXS, and in relevant rodent models. This includes electroencephalographic measurement of event related potentials, neural oscillations and mismatch negativity, as well as habituation and pre-pulse inhibition of startle. We outline robust evidence of disrupted sensory processing in individuals with ASD and FXS, and in respective animal models, focusing on the auditory sensory domain. Animal models provide an excellent opportunity to examine common mechanisms of sensory pathophysiology in order to develop therapeutics.

Passage through stationary phase advances replicative aging in Saccharomyces cerevisiae

Saccharomyces cerevisiae mother cells undergo an aging program that includes morphologic changes, sterility, redistribution of the Sir transcriptional silencing complex from HM loci and telomeres to the nucleolus, alterations in nucleolar architecture, and accumulation of extrachromosomal ribosomal DNA circles (ERCs). We report here that cells starved for nutrients during prolonged periods in stationary phase show a decrease in generational lifespan when they reenter the cell cycle. This shortened lifespan is not transmitted to progeny cells, indicating that it is not due to irreversible genetic damage. The decrease in the lifespan is accompanied by all of the changes of accelerated aging with the notable exception that ERC accumulation is not augmented compared with generation-matched, nonstarved cells. These results suggest a number of models, including one in which starvation reveals a component of aging that works in parallel with the accumulation of ERCs. Stationary-phase yeast cells may be a useful system for identifying factors that affect aging in other nondividing eukaryotic cells.

A retrospective review of the relationship between facial fractures, head injuries, and cervical spine injuries

Facial fractures are common in the multiply-traumatized patient, and the results of previous studies that have examined the relationship between facial fractures, cervical spine injuries, and head injuries have produced conflicting results. A retrospective review of 1,050 blunt-trauma patients during a 40-month period at a regional trauma unit revealed 168 patients with facial fractures. The average injury severity score (ISS) of these patients with facial fractures was 31 compared with an average ISS of 25.6 for the entire group. There were 266 facial fractures in these 168 patients: mandible (n = 72), maxilla (n = 74), zygoma (n = 52), orbital (n = 46), nasoethmoidal (n = 20), and frontal (n = 2). There were seven (4%) cervical spine injuries, three of which were atlanto-occipital subluxations in patients who ultimately died. Of the four surviving patients, one had a cord injury. In contrast, 145 (85%) showed evidence of head injuries; 64 (38%) of these head injuries were serious and 17 of these patients required craniotomy. The relationship of facial fractures and cervical spine injuries may be over emphasized; head injuries, although frequently minor, are much more commonly associated with facial fractures.

GABA-B Agonist Baclofen Normalizes Auditory-Evoked Neural Oscillations and Behavioral Deficits in the Fmr1 Knockout Mouse Model of Fragile X Syndrome

Fragile X syndrome is a genetic condition resulting from FMR1 gene mutation that leads to intellectual disability, autism-like symptoms, and sensory hypersensitivity. Arbaclofen, a GABA-B agonist, has shown efficacy in some individuals with FXS but has become unavailable after unsuccessful clinical trials, prompting interest in publicly available, racemic baclofen. The present study investigated whether racemic baclofen can remediate abnormalities of neural circuit function, sensory processing, and behavior in Fmr1 knockout mice, a rodent model of fragile X syndrome. Fmr1 knockout mice showed increased baseline and auditory-evoked high-frequency gamma (30-80 Hz) power relative to C57BL/6 controls, as measured by electroencephalography. These deficits were accompanied by decreased T maze spontaneous alternation, decreased social interactions, and increased open field center time, suggestive of diminished working memory, sociability, and anxiety-like behavior, respectively. Abnormal auditory-evoked gamma oscillations, working memory, and anxiety-related behavior were normalized by treatment with baclofen, but impaired sociability was not. Improvements in working memory were evident predominantly in mice whose auditory-evoked gamma oscillations were dampened by baclofen. These findings suggest that racemic baclofen may be useful for targeting sensory and cognitive disturbances in fragile X syndrome.

Measurement of day and night neutrino energy spectra at SNO and constraints on neutrino mixing parameters

The Sudbury Neutrino Observatory (SNO) has measured day and night solar neutrino energy spectra and rates. For charged current events, assuming an undistorted 8B spectrum, the night minus day rate is 14.0%+/-6.3%(+1.5%)(-1.4%) of the average rate. If the total flux of active neutrinos is additionally constrained to have no asymmetry, the nu(e) asymmetry is found to be 7.0%+/-4.9%(+1.3%)(-1.2%). A global solar neutrino analysis in terms of matter-enhanced oscillations of two active flavors strongly favors the large mixing angle solution.

A novel form of diffusion battery

A novel form of diffusion battery uses a series of 635-mesh screens instead of the customary cluster of circular tubes or holes. Fifty-five screens are arranged in series so that the amount of aerosol penetrating through different numbers of screens can be measured with a condensation nuclei counter. This "filter stack" must be calibrated because theory is not available to calculate the performance of such screens with sufficient accuracy. For calibration a polydisperse aerosol such as ambient or silver aerosol is used to compare the performance of the screens with that of the cluster-tube and collimated-holes diffusion batteries, whose performance is known from theory. It was observed that a given number of screens is equivalent to a given number of batteries independent of the size or size distribution of the aerosol. This filter stack is very compact and light in weight (0.9 kg). It is particularly useful for measurements in the field.

The evaluation of suspected renal colic: ultrasound scan versus excretory urography

Patients commonly present to the emergency department with a suspected diagnosis of renal colic. A prospective study of 98 patients presenting with acute flank or abdominal pain or both was conducted to determine the diagnostic accuracy of ultrasound scan compared with excretory urography for the diagnosis of urinary tract calculi. All patients underwent standardized ultrasound scan and excretory urography as independent procedures. Two staff radiologists who reported the procedures were blinded to the results of the other diagnostic test and ultimate clinical outcome. All patients discharged home from the ED were followed to the hospital urology clinic. The diagnosis of urinary calculus was made only by identification of calculus at surgery or by reported passage of a stone by the patient. Of 85 patients available for follow-up study (56 men, 29 women; mean age, 40.5 years; range 18 to 77 years), calculi were identified in 69 (81%). Ultrasound identified calculi in 44 patients (sensitivity, 64%; specificity, 100%). Excretory urography identified calculi in 44 patients (identical sensitivity and specificity). When the presence of obstructive hydronephrosis only was used to diagnose renal calculi, ultrasound scan identified 59 patients (sensitivity, 85%; specificity, 100%) and excretory urography identified 62 patients (sensitivity, 90%; specificity, 94%). When the results of both diagnostic modalities were combined, calculi were identified in 59 patients (sensitivity, 85%; specificity, 100%) and hydronephrosis was seen in 66 patients (sensitivity, 95%; specificity, 94%). Our study shows that the diagnostic abilities of these procedures are equal in the detection of renal calculi.(ABSTRACT TRUNCATED AT 250 WORDS)

Measurement of the total active 8B solar neutrino flux at the Sudbury Neutrino Observatory with enhanced neutral current sensitivity

The Sudbury Neutrino Observatory has precisely determined the total active (nu(x)) 8B solar neutrino flux without assumptions about the energy dependence of the nu(e) survival probability. The measurements were made with dissolved NaCl in heavy water to enhance the sensitivity and signature for neutral-current interactions. The flux is found to be 5.21 +/- 0.27(stat)+/-0.38(syst) x 10(6) cm(-2) s(-1), in agreement with previous measurements and standard solar models. A global analysis of these and other solar and reactor neutrino results yields Deltam(2)=7.1(+1.2)(-0.6) x 10(-5) eV(2) and theta=32.5(+2.4)(-2.3) degrees. Maximal mixing is rejected at the equivalent of 5.4 standard deviations.

Multiple receptors for brain dopamine

This study was done to obtain direct in vitro evidence for the possible existence of more than one type of dopaminergic binding site in homogenates of the caudate nucleus from calf brain. Five radioligands for dopaminergic sites were tested. The inhibitions of two agonist radioligands ([3H]dopamine, [3H]apomorphine) by haloperidol, chlorpromazine, or piflutixol were biphasic. The inhibitions of [3H]haloperidol, [3H]spiroperidol, and [3H]dihydroergocryptine binding by dopamine and (-)-norepinephrine were also biphasic. Thus, both 3H-labeled agonists and 3H-labeled antagonists were possibly binding to two high-affinity sites.

Chromosomal structure is altered by mutations that suppress or enhance position effect variegation

We examined the genetic, morphological, and molecular effects of position effect variegation in Drosophila, and the effects of mutations that either suppress [Su(var)] or enhance [E(var)] this phenomenon. All eight Su(var) mutations examined strongly suppress the inactivation of variegating alleles of the genes white [In(l) wm4], brown [In(2R) bwVDe2] and Stubble [T(2; 3) SbV]. The E(var) mutation enhances variegation of these loci. The chromosomal region 3C-E (26 bands) which includes the white locus is usually packaged as heterochromatin in salivary glands of the variegating strain wm4. Addition of any of the Su(var) mutations restores a more euchromatic morphology to this region. In situ hybridization to polytene chromosomes and DNA blot analyses of gene copy number demonstrate that the DNA of the w+ gene is less accessible to its probe in the variegating wm4 strain than it is in the wild-type or variegation-suppressed strains. Blot analysis of larval salivary gland DNA indicates that the white gene copy number does not vary among the strains. Hence, the differences in binding of the w+ gene probe in the variegating and variegation-suppressed strains reflect differences in chromosomal packaging rather than alterations in gene number. The effects of variegation and the Su(var) mutations on chromatin structure were analyzed further by DNAse I digestion and DNA blot hybridization. In contrast to their dramatic effects on chromosomal morphology and gene expression, the Su(var) mutations had negligible effects on nuclease sensitivity of the white gene chromatin. We suggest that the changes in gene expression resulting from position effect variegation and the action of the Su(var) mutations involve alterations in chromosomal packaging.

Controlled-release oxycodone and naloxone in the treatment of chronic low back pain: a placebo-controlled, randomized study

BACKGROUND

For Canadian regulatory purposes, an analgesic study was required to complement previously completed, pivotal studies on bowel effects and analgesia associated with controlled-release (CR) oxycodone⁄CR naloxone.

OBJECTIVES

To compare the analgesic efficacy and safety of CR oxycodone⁄CR naloxone versus placebo in patients with chronic low back pain.

METHODS

Patients requiring opioid therapy underwent a two- to seven-day opioid washout before being randomly assigned to receive either 10 mg⁄5 mg CR oxycodone⁄CR naloxone or placebo every 12 h, titrated weekly according to efficacy and tolerability to 20 mg⁄10 mg, 30 mg⁄15 mg or 40 mg⁄20 mg every 12 h. After four weeks, patients crossed over to the alternative treatment for an additional four weeks. Acetaminophen⁄codeine (300 mg⁄30 mg every 4 h to 6 h as needed) was provided as rescue medication.

RESULTS

Of the 83 randomized patients, 54 (65%) comprised the per-protocol population. According to per-protocol analysis, CR oxycodone⁄CR naloxone resulted in significantly lower mean (± SD)pain scores measured on a visual analogue scale (48.6 ± 23.1 mm versus 55.9 ± 25.4 mm; P=0.0296) and five-point ordinal pain intensity scores (2.1 ± 0.8 versus 2.4 ± 0.9; P=0.0415) compared with placebo. After the double-blinded phase, patients and investigators both preferred CR oxycodone⁄CR naloxone over placebo. These outcomes continued in the 79% of patients who chose to continue receiving CR oxycodone⁄CR naloxone in a six-month, open-label evaluation.

CONCLUSIONS

In patients complying with treatment as per protocol, CR oxycodone⁄CR naloxone was effective for the management of chronic low back pain of moderate or severe intensity.

Seasonal pseudohyperkalaemia

AIMS

To investigate the relation between ambient temperature and serum potassium concentrations in samples from primary care.

METHODS

Potassium concentrations were estimated on general practitioner and hospital ward samples taken over a two year period using serum obtained from gel separator samples. The number of samples analysed from general practice during each month varied from 5093 to 8978 (mean of 7068 samples/month).

RESULTS

As the temperature fell in winter, the mean daily serum potassium concentration rose in samples from general practice, with the inverse occurring during the warmer summer months. This effect was restricted to samples coming from general practice, with inpatient samples seemingly unaffected.

CONCLUSIONS

These results indicate that exposure of the samples to variations in ambient temperature during their transport to the laboratory profoundly affects measured serum potassium concentrations.