Index radiographic measurements in the prediction of progression in infantile idiopathic scoliosis: a comparative analysis and description of a novel predictive model.

PURPOSE: To assess the comparative accuracy of commonly utilised index radiological measurements in the prognosis of infantile idiopathic scoliosis (IIS) and build a parsimonious prognostic model utilising these measurements. METHODS: This was a retrospective analysis of a UK population of patients with IIS. Index radiological parameters were analysed, and outcome of their condition was determined over long-term follow-up. Comparative accuracy of each radiological measurement category was determined by logistic regression analyses and the corresponding receiver operating characteristic (ROC) curve. A predictive model of IIS progression using these measurements was then created. RESULTS: All three radiological measurement categories were predictive of IIS progression. However, on pairwise comparison of ROC curves and multivariate analysis, the index Cobb angle proved the most significant predictor of curve progression. Using the index Cobb angle only, a predictive model of curve progression achieved an accuracy of 81.18% with a cut-off Cobb angle of 34.5° found to be the optimal threshold to discriminate a progressive from resolving curve. CONCLUSION: Of the three analysed index radiological parameters commonly used by surgeons in the prognosis of IIS, we found that the Cobb angle is the most accurate predictive measure. Further, neither addition of the RVAD nor convex RVA provided significant further prognostic value in a multivariate model of progression. However, not even the Cobb angle model was accurate in all cases; emphasising caution should be applied when relying on index radiological measurements to predict IIS outcomes.

Long-term follow-up of patients with infantile idiopathic scoliosis: is the rib vertebra angle difference (RVAD) a reliable indicator of evolution?

PURPOSE: Since its original description by Mehta, the rib vertebra angle difference (RVAD) and, in particular, a threshold of 20° have become an accepted and widely utilised prognostic indicator in the assessment of patients presenting with an infantile idiopathic scoliosis (IIS). However, uncertainty in the utility of the RVAD in the prognosis of IIS remains. The aims of this study were to investigate the prognostic significance of the RVAD and to describe the changes in RVAD over long-term follow-up of patients with progressive and resolving IIS. METHODS: This was a retrospective analysis of patients presenting with IIS at a tertiary spinal deformity unit in the UK. Serial patient radiographs were reviewed and a logistic regression model using the patients index RVAD was created to predict the likelihood of curve progression. RESULTS: At both index presentation and over long-term follow-up, patients with a progressive curve had significantly greater mean Cobb angle and RVAD measurements than those with resolving curves. The RVAD and Cobb were found to correlate positively in both groups, reflecting the underlying costovertebral pathoanatomy. The logistic regression model demonstrated that the optimal RVAD threshold in predicting IIS progression was lower at 17.1° than the 20° cut-off previously advocated. CONCLUSION: This study describes the utility of the RVAD in predicting IIS evolution. From this analysis, we would advise caution in predicting outcomes based on the index RVAD at presentation. LEVEL OF EVIDENCE: II.

Randomized trial of informed consent and recruitment for clinical trials in the immediate preoperative period.

BACKGROUND: The standard process of obtaining informed consent sometimes prevents physicians or patients from participating in clinical trials, partly because they are concerned about eventual treatment allocation or the physician is concerned the patient might harbor some uncertainty about the best treatment. Alternative randomization methods have been advocated that may address these and other concerns. METHODS: After institutional ethics committee gave its approval, the authors interviewed 770 patients before operation and asked them to consider enrolling in a mock anesthesia trial. Patients were allocated randomly to one of five methods of randomization and consent: one-sided informed consent (the most common approach), prerandomized consent to experimental treatment, prerandomized consent to standard treatment, one-sided physician-modified informed consent, or one-sided patient-modified informed consent. Recruitment rates were compared and sociodemographic and perioperative predictors of recruitment were identified. RESULTS: The randomization method did not result in any significant difference in recruitment rates: one-sided informed consent, 55.6%; prerandomized consent to experimental treatment, 53.3%; prerandomized consent to standard treatment, 53%; one-sided physician-modified informed consent, 60.7%; and one-sided patient-modified informed consent, 56.7% (P = 0.66). Multivariate predictors of recruitment were patient age >45 yr (odds ratio, 1.44; 95% confidence interval [CI], 1.08 to 1.93), English-speaking at home (1.49; 1.0 to 2.21), and male researcher-male patient interaction (1.37; 1.20 to 1.57). CONCLUSIONS: No evidence emerged that alternative randomization and consent designs resulted in increased recruitment rates compared with simple one-sided informed consent for a sham anesthesia trial in patients awaiting elective surgery. Older, male patients were more likely to provide consent.

Intraoperative cardiac arrest after unrecognized dynamic hyperinflation.

We report a case of intraoperative dynamic hyperinflation ("gas trapping") which led to cardiac arrest, with electromechanical dissociation. The features of this poorly recognized phenomenon are described.

Chemical dependence in anaesthetic registrars in Australia and New Zealand.

The Supervisors of Anaesthetic Training in Australia and New Zealand were surveyed and asked to report any cases of chemical dependence from anaesthetic registrars at their hospital from 1981 to 1991. From 83 questionnaires there were 65 (78%) returned. There were 14 departments (22%) with experience of one or more cases during this interval. Only five (7%) reported conducting a lecture or tutorial on the problem. The departmental reports covered 4425 registrar years of training and there were 17 cases reported. Of these, 13 were complete and are considered in detail. It is estimated that 1.3% of those who entered anaesthetic training during the interval were recognised to become chemically dependent during their training. Follow-up was available on only six of the 13 registrars and only one was reported to have completed training. The results of this survey indicate that chemical dependence is already a major health problem amongst anaesthetic registrars in Australia and New Zealand.

The effect of access to lethal methods of injury on suicide rates.

The relationship between the availability of lethal methods of injury and suicide rates is an important, but unresolved question. We investigated this relationship by prospectively classifying lethal methods according to their accessibility in the five counties of New York City. These counties have both similarities and differences in the proportion of their populations with access to specific lethal means. We then compared the age- and gender-adjusted method-specific suicide rates of these counties. There were marked differences in overall crude suicide rates among the five counties. The counties had similar suicide rates involving methods that were equally accessible to all persons in each county (eg, hanging, laceration, suffocation, and burns) as well as methods that were accessible to a smaller, but similar proportion of the population in each county (eg, firearms and drowning in waterways). Virtually all of the differences in overall suicide risk among counties were explained by differences in rates involving methods that were differentially available in the counties, principally fall from height, overdose of prescription medications, and carbon monoxide poisoning. We conclude that differences in suicide rates between communities are, in large part, due to differences in accessibility to lethal methods of injury. Therefore, systematic studies should evaluate the effect of reducing accessibility to specific lethal means on suicide rates.

Prevalence of cocaine use among residents of New York City who committed suicide during a one-year period.

OBJECTIVE: In the mid-1980s the form of cocaine called "crack" became widely available in New York City. The authors sought to determine the prevalence of cocaine metabolites detected at autopsy in persons who committed suicide in New York City during this period. METHOD: Individual reviews of the autopsy and toxicological records of all persons under the age of 61 who had committed suicide in the city during a 1-year period were conducted to determine demographic characteristics, suicide methods, and cocaine and alcohol use at the time of death. RESULTS: In one of every five cases studied, the person who committed suicide had used cocaine within days of his or her death. The prevalence of cocaine use among young Hispanic males who committed suicide was 45%. Persons who were young, black, or Hispanic and who had used alcohol immediately before the fatal injury were most likely to have been recent cocaine users. After controlling for demographic variables and ethanol use, the investigators found that individuals who committed suicide with firearms were twice as likely to have used cocaine as those who used other methods. CONCLUSIONS: In contrast to the results of regional and household surveys during this period, which suggested that the current prevalence of cocaine use in New York City was 3%-5%, these results suggest a high prevalence of cocaine use in the days immediately preceding death by young persons who commit suicide. Additional studies are needed to determine how cocaine may act as a risk factor for suicide.

Prevalence of recent cocaine use among motor vehicle fatalities in New York City.

We determined the prevalence of recent cocaine and alcohol use among motor vehicle fatalities occurring in New York, NY, from 1984 through 1987. Recent cocaine use was detected at autopsy in 18.2% of the sample and no significant difference between drivers (20.0%) and passengers (13.9%) was found. Both alcohol and cocaine metabolites were found in 10.0% of cases tested. The prevalence of cocaine metabolites or alcohol detected in driver fatalities aged 16 through 45 years did not change significantly when the period prior to the widespread availability of "crack" cocaine (1984 through 1985) was compared with the period immediately following the introduction of crack cocaine (1986 through 1987). Additional studies are needed both to elucidate the association between cocaine use and these fatalities and to determine the value of screening persons seriously injured in traffic accidents in areas where such drug use is endemic.

Increased risk of suicide in persons with AIDS.

The rate of suicide has been reported to be higher in persons with chronic and life-threatening illnesses (eg, cancer, Huntington's disease, and renal failure). We studied the rate of suicide in 1985 in New York City residents diagnosed with the acquired immunodeficiency syndrome (AIDS). There were 668 suicides in New York City residents in 1985, yielding a rate of 9.29 per 100,000 person-years. In men aged 20 to 59 years without a known diagnosis of AIDS, the rate was 18.75 per 100,000 person-years. There were 3828 individuals who lived with the diagnosis of AIDS for some part, or all, of 1985. There were 12 suicides in men aged 20 to 59 years from this group who lived 1763.25 person-years with a diagnosis of AIDS. This yields a suicide rate of 680.56 per 100,000 person-years. Thus, the relative risk of suicide in men with AIDS aged 20 to 59 years was 36.30 times (95% confidence limits, 20.45 to 64.42) that of men aged 20 to 59 years without this diagnosis, and 66.15 times (95% confidence limits, 37.38 to 117.06) that of the general population. We conclude that AIDS represents a significant risk factor for suicide.

Correction of subnormal fertility with copper and magnesium supplementation.

Two hundred and four Holstein cows and heifers were randomly assigned to mineral supplement groups 30 d prior to expected calving. Supplement treatment groups were Cu, Mg, Cu plus Mg, and no mineral supplement. The total diet of supplemented groups averaged 15 mg/kg of Cu and .30% of Mg. Pastures consisted of bermudagrass, bahiagrass, and millet during the summer and oats and ryegrass mixture during the winter. Corn and sorghum silage were also fed. Blood samples were taken just prior to initiation of mineral supplementation and at wk 1, 2, 4, 6, and 8 postpartum. Hemoglobin and packed cell volume were determined and plasma was assayed for Cu and Mg. First service conception rates were 57% for the Cu plus Mg treatment and 27, 38, and 33% for treatments 1, 2, and 4, respectively. Ninety-two percent of the cows in the Cu plus Mg-group conceived by 210 d postpartum as opposed to an average of 75% for the other groups. Plasma Mg was different among cows grouped on a fertility basis and hemoglobin was correlated with days to conception. Plasma Mg was correlated with hemoglobin. Both were inversely related to postcalving infection and uterine involution. In summary, cows supplemented with both Cu and Mg showed improved fertility, whereas those supplemented with Cu or Mg alone did not.

Relationship between fertility and blood glucose and cholesterol concentrations in Holstein cows.

Jugular blood samples were collected prepartum and postpartum from 97 Holstein cows and heifers. Samples were analyzed for total serum cholesterol and plasma glucose. Plasma samples taken 4, 11, 18, and 25 days postpartum were also analyzed for progesterone. Concentrations of cholesterol, glucose, and progesterone were evaluated in relation to summer- and winter-calving seasons, milk production, lactation number, days-to-conception, number of postcalving uterine infusions given, and time relative to calving. A temperature-humidity index was used as a covariate in the analysis to adjust the data for climatic effects so that seasonal effects other than temperature and humidity could be determined. Average plasma glucose was within the normal range (62 +/- 8 mg/dl). It increased before calving and then declined to a minimum value between 11 and 25 days postpartum. Glucose then increased after 25 days for the summer-calving group and remained relatively stable for the winter-calving cows. Blood glucose concentrations were inversely related to milk production. Negative correlations existed between milk production and plasma glucose at days 4, 11, 18, 25, and 39 postpartum. First-lactation heifers had higher blood glucose levels than cows in their second or later lactation. Blood glucose concentrations were not related to days-to-conception over both seasons. Average serum cholesterol was within the normal range (125 +/- 29 mg/dl). It decreased before calving and then increased for 88 days after calving. Summer-calving cows had higher serum cholesterol concentrations prepartum and winter-calving cows had higher concentrations from 39 through 88 days postpartum. Cholesterol concentrations were directly related to milk production from 25 through 88 days postpartum.(ABSTRACT TRUNCATED AT 250 WORDS)

Selenium concentrations in feeds and effects of treating pregnant Holstein cows with selenium and vitamin E on blood selenium values and reproductive performance.

Holstein cows (n = 104) and heifers (n = 35) were used to determine the effects of treatment with selenium (Se) and vitamin E on whole blood Se values and fertility. At 21 +/- 3 days before parturition, 55 cows and 19 heifers were injected with 680 IU of vitamin E and 50 mg of Se as sodium selenite. Treatment had no effect on days to first estrus, days to first service, days to conception, services per conception, or number of uterine infusions required. Blood samples were obtained from 33 nontreated cows and heifers and 32 treated animals at 21 and 14 days (+/- 3) before calving and at 7 and 14 days (+/- 3) after calving. Mean whole blood Se level at -21 days (day 0 was day of parturition) and before Se-vitamin E treatment was 0.109 micrograms/ml. At days -14, 7, and 14, blood Se was significantly higher in the treated than the non-treated animals. Blood Se was lower on all sampling days in cows calving in July through November than in cows calving in December through April. Heifers in their 1st lactation had lower blood Se concentrations than did cows in their 2nd or later lactation. In feeds sampled at 2-week intervals, mean concentrations of Se in Bahia grass, mixed ryegrass and oats, corn silage, and sorghum silage were less than 0.1 micrograms/g on a dry matter basis. Bermuda grass, alfalfa hay, and concentrates contained greater than 0.1 micrograms of Se/g. Large variation existed in Se concentrations of individual feedstuffs.

Plasma copper concentration and packed cell volume and their relationships to fertility and milk production in Holstein cows.

Jugular blood samples were obtained from 55 summer-calving and 40 winter-calving Holstein cows fed diets which averaged 7.4 micrograms of Cu/g. Samples were collected within 3 days of 30, 11, and 4 days before calving and 4, 11, 18, 25, 39, 60, 88, 116, and 147 days after calving. Packed cell volume and plasma Cu concentrations were determined. Blood components were analyzed in relationship to season, milk production, lactation number, number of days to conception, number of postcalving uterine infusions, and time relative to calving. The environmental temperature-humidity index was used as a covariate in the analysis, so that seasonal effects represented feeding or production differences between seasons and were not due to the direct effects of climate. Plasma Cu concentrations were within the usual laboratory limits (1.05 +/- 0.20 microgram/ml). These values were unrelated to PCV in the summer-calving cows, but were slightly related in the winter-calving cows (r = 0.11). Plasma Cu values increased around the time of calving, with the maximum level (1.13 microgram/ml) occurring on postpartum day 11. Plasma Cu concentration was higher in cows that conceived within 80 days of calving than in cows which conceived at 120 days or more. Differences in plasma Cu among fertility groups were most evident during postpartum days 25 to 60. However, the relationship between plasma Cu concentrations and fertility was not consistent. Significant interactions existed for season X fertility groups and milk production groups X fertility groups. Plasma Cu concentration was significantly higher for the summer-calving cows and was inversely related to milk production level.(ABSTRACT TRUNCATED AT 250 WORDS)

Severe drug overdose: results of treatment.

The incidence and management of severe drug overdose patients over a five-year period is presented, together with results and complications. Emphasis is placed on the importance of conservative measures with minimal need for more aggressive methods of treatment.