A community outreach lead screening program using capillary blood collected on filter paper

OBJECTIVE

To test whether a method of fingerstick blood sample collection onto filter paper could be used as an alternative screening method in the field in settings where environmental lead contamination is a high risk.

METHOD

Members of the Pediatric Mobile Team of Children's Hospital of Michigan, Detroit, collected paired venous and capillary blood samples from 120 children, aged 6 months to 6 years, who presented for services at any of 7 sites located in decaying neighborhoods of older sections of Detroit. All samples were analyzed for lead content by graphite furnace atomic absorption spectrometry.

RESULTS

When filter paper samples with blood lead levels of 0.48 micromol/L (10 microg/dL) or higher were compared with matched venous samples, the concordance coefficient was 0.96. The sensitivity and specificity of the filter paper samples relative to the venous samples for a cutoff of 0.48 micromol/L (10 microg/dL) or higher were 94% and 99%, respectively, with a positive predictive value of 97%. However, at a cutoff of 0.72 micromol/L (15 microg/dL), the sensitivity and specificity dropped to 75% and 98%, respectively, with filter paper samples underreporting blood lead values. At any cutoff point (0.48, 0.72, or 0.96 micromol/L [10, 15, or 20 microg/dL]), the filter paper method was highly specific for lead.

CONCLUSIONS

Capillary filter paper sampling is an accurate and practical alternative to venous sampling for blood lead screening using 0.48 micromol/L (10 microg/dL) as the cutoff. The filter paper method predicts levels of 0.72 micromol/L (15 microg/dL) or higher less well. The cause of divergent values above 0.72 micromol/L (15 microg/dL) is not clear. Environmental contamination of capillary filter paper, however, does not seem to be an explanation.

Disclosure of contextually hidden sexual images embedded in an advertisement

The discovery of sexual images embedded in an advertisement significantly affected responses to the advertisement by 147 female and 159 male undergraduates.

Increased frequency of expression of elevated dihydrofolate reductase in T-cell versus B-precursor acute lymphoblastic leukemia in children

The relationships between dihydrofolate reductase (DHFR) levels or methotrexate membrane transport and acute lymphoblastic leukemia (ALL) immunophenotype were evaluated on 51 T-cell and 44 B-precursor ALL specimens from 90 pediatric ALL patients at diagnosis and relapse, using a fluorescent methotrexate analog (PT430) and flow cytometry assay (Matherly et al, Blood 85:500, 1995). For T-cell ALL, 35 of 45 (78%) of newly diagnosed patients' specimens exhibited elevated DHFR relative to DHFR levels in ALL blasts from methotrexate-responsive patients. For 30 of 45 diagnostic T-ALL specimens, DHFR expression was heterogeneous, with up to 3 separate subpopulations covering a 44-fold range; the DHFR-overproducing fractions comprised 10% to 88% of the total blasts. Elevated DHFR was less common in B-precursor ALL at diagnosis, being detected in only 17 of 36 specimens (47%); 11 of these samples exhibited DHFR heterogeneity. Median maximal DHFR levels were fourfold higher in T-cell than B-precursor ALL at diagnosis. Within a particular phenotypic group, there were no correlations between DHFR levels and patient prognostic features, including age, sex, chromosomal abnormalities, white blood cell counts (WBCs), and percentage of S-phase. However, for B-precursor ALL, there was a notably higher fraction of African-American than white patients with elevated DHFR. For patients (both phenotypes) with low WBCs (<50,000/ microL), event-free survival times were significantly shorter for those expressing DHFR above a threshold level than for patients expressing DHFR below this level (P < .016); this relationship was not seen for patients with high WBCs (>50,000/microL). Elevated DHFR was detected in 11 of 14 relapse specimens (5 of 6 T-cell and 6 of 8 B-precursor). Two of five paired relapse specimens (both T-cell) from patients treated with methotrexate exhibited increased DHFR levels over those at diagnosis (2.5- to 5-fold); the fraction of DHFR-overproducing blasts was also increased in 4 of 5 paired relapse specimens (2 B-precursor and 2 T-cell). In contrast to the variations in DHFR, highly impaired methotrexate transport was detected in only 6 of 95 ALL specimens, including both diagnosis and relapse. There was no correlation between phenotype and impaired transport. These data provide further rationale for the use of mechanistically based prognostic factors to complement known biologic or disease-based prognostic indicators in the design of ALL therapy including methotrexate, particularly with patients presenting with low WBCs. The finding of a markedly increased frequency of DHFR overexpression in T-cell over B-precursor ALL suggests that this difference is associated with the poorer prognosis of patients with T-cell ALL treated with standard-dose antimetabolite therapy and implies that higher-dose methotrexate (> or = 1 g/m2) during consolidation therapy may be useful in the treatment of this disease.

Mortality within the first 2 years in infants exposed to cocaine, opiate, or cannabinoid during gestation

OBJECTIVE

To determine the mortality rate, during the first 2 years of life, in infants who were exposed to cocaine, opiate, or cannabinoid during gestation.

METHODS

For a period of 11 months, a large group of infants were enrolled and screened at birth for exposure to cocaine, opiate, or cannabinoid by meconium analysis. Death outcome, within the first 2 years after birth, was determined in this group of infants using the death registry of the Michigan Department of Public Health.

RESULTS

A total of 2964 infants was studied. At birth, 44% of the infants tested positive for drugs: 30. 5% positive for cocaine, 20.2% for opiate, and 11.4% for cannabinoids. Compared to the drug negative group, a significantly higher percentage (P < .05) of the drug positive infants had lower weight and smaller head circumference and length at birth and a higher percent of their mothers were single, multigravid, multiparous, and had little to no prenatal care. Within the first 2 years of life, 44 infants died: 26 were drug negative (15.7 deaths per 1000 live births) and 18 were drug positive (13.7 deaths per 1000 live births). The mortality rate among cocaine, opiate, or cannabinoid positive infants were 17.7, 18.4, and 8.9 per 1000 live births, respectively. Among infants with birth weight </=2500 g, infants who were positive for both cocaine and morphine had a higher mortality rate (odds ratio = 5.9, confidence interval [CI] = 1.4 to 24) than drug negative infants. Eleven infants died from the sudden infant death syndrome (SIDS); 58% were positive for drugs, predominantly cocaine. The odds ratio for SIDS among drug positive infants was 1.5 (CI = 0.46 to 5.01) and 1.9 (CI = 0.58 to 6.2) among cocaine positive infants.

CONCLUSION

We conclude that prenatal drug exposure in infants, although associated with a high perinatal morbidity, is not associated with an overall increase in their mortality rate or incidence of SIDS during the first 2 years of life. However, a significantly higher mortality rate was observed among low birth weight infants (</=2500 g) who were positive for both cocaine and opiate.

Parent and adolescent perceived need for parental consent involving research with minors

OBJECTIVE

To assess parents' and adolescents' perceived need for parental consent for minor adolescents to participate in minimal risk research studies based on procedural invasiveness (anonymous surveys, interviews, and blood or urine testing) and sensitivity of the topics (sexuality, drug and alcohol use, and sexually transmitted diseases and human immunodeficiency virus [HIV]).

METHODS

An anonymous self-report questionnaire was administered to 100 adolescent-parent pairs at 2 clinical sites (urban and suburban) of Children's Hospital of Michigan in Detroit.

RESULTS

By invasiveness of the research procedure, the proportions of parents and adolescents who perceived a need for parental consent were as follows: face-to-face interviews, 62% vs 48%; telephone interviews, 72% vs 46%; blood or urine testing, 77% vs 62%; and blood testing for HIV status, 78% vs 59%. These differences were only significant for telephone interviews and HIV blood testing. For anonymous surveys, a minority of parents (33%) and adolescents (26%) reported that parental consent was needed. Based on sensitivity of the research topics, the proportions of parents and adolescents who perceived a need for parental consent were as follows: sexuality, 60% vs 34%; drug and alcohol use, 56% vs 44%; contraception, 62% vs 46%; and sexually transmitted diseases and HIV testing, 56% vs 52%. These differences were only significant for sexuality. Parents with higher education believed that teens could give their own consent (P < .05). Fifty-seven percent of parents and their teens agreed that parental consent for anonymous surveys was not necessary. For more invasive procedures and more sensitive topics, the percentage of disagreement ranged from 28% to 55.5%.

CONCLUSIONS

There is a greater perceived need for parental consent to adolescent participation in research studies among parents than among teens for more invasive procedures and more sensitive topics. These results suggest the need for sensitivity to differing adolescent and parental perceived need for parental consent for a minor adolescent to participate in such studies. Further studies with larger samples are needed to determine what factors influence diverse parent and adolescent opinions.

Moxonidine and cognitive function: interactions with moclobemide and lorazepam

OBJECTIVE

Moxonidine represents a new generation of centrally acting antihypertensive drugs. It binds to I1-imidazoline receptors and exerts its antihypertensive activity through a reduction in systemic vascular resistance, while cardiac output remains unchanged or even increases slightly. Moxonidine is prescribed for the treatment of mild to moderate hypertension. Typical doses are 0.4 to 2.0 mg given as one dose in the morning or as divided doses in the morning and evening.

METHODS

The effects of moxonidine 0.4 mg once daily in combination with moclobemide or lorazepam were investigated in two, double-blind, randomised, placebo-controlled, two-way crossover studies in a total of 48 healthy volunteers. Safety assessments were made in each study and included pre- and post-study measurement of blood pressure, heart rate, ECG, haematology, blood biochemistry, and urinalysis, and recording of adverse events.

RESULTS

In the first study, moxonidine alone was found to produce small but statistically significant impairments of vigilance detection speed at 4 h and 6 h. Lowering of subjective alertness was also observed. Repeat dosing with moxonidine produced an impairment of memory scanning performance. These findings were not reproduced in the second study, in which moxonidine alone produced an improvement in immediate word recall at 4 h and 6 h. No interactions were observed when moxonidine was co-administered with moclobemide. Moxonidine, when co-administered with lorazepam, produced interactions with three tasks requiring high levels of attention: choice, simple reaction time and digit vigilance performance; memory tasks; immediate word recall, delayed word recall accuracy; and visual tracking. A total of 47 adverse events were reported in study 1. Moxonidine produced a slight decrease of systolic and diastolic blood pressure. In study 2, a total of 55 adverse events were reported. In both trials, the most frequently reported events were tiredness and dryness of mouth, the latter occurring only under the moxonidine treatment. There were no clinically relevant changes observed in blood pressure, pulse rate, and laboratory tests in either study, nor was there any evidence of any interaction between moxonidine and either moclobemide or lorazepam.

CONCLUSION

Moxonidine was found to be safe and well tolerated in healthy volunteers. However, the impairments on attentional tasks were greater when moxonidine was co-administered with lorazepam 1 mg. These effects should be considered when moxonidine is codosed with lorazepam, although they were smaller than would have been produced by a single dose of lorazepam 2 mg.

The accumulation of whole body skeletal mass in third- and fourth-grade children: effects of age, gender, ethnicity, and body composition

The purpose of this longitudinal study is to describe bone mass and body composition, and the annual changes in these measurements, among third grade students recruited from a suburban school district. Whole body bone mineral content (WBBMC), bone mineral density (WBBMD), fat, and lean mass were measured by dual-energy X-ray absorptiometry. Bone mass in the lumbar spine (LBMC) region of the whole body scan was also utilized. 773 students (38% white, 57% black, 5% other) had baseline visits; 561 had a second measurement a year later. At baseline, black children have significantly higher WBBMC, WBBMD, height, and lean mass than whites. Black males, but not black females, have a greater LBMC. There are no significant gender differences in body size, WBBMC, or WBBMD, although girls have a greater LBMC and fat mass, and boys have a higher lean mass. Most of these differences persist in visit 2. The annual change in bone and lean mass is greater in blacks. Stepwise linear regression analyses of bone mass on body size, gender, and ethnicity and their interactions indicate that log-transformed weight explains most of the variance in both WBBMC and WBBMD (multiple r2 = 0.90 and 0.64, respectively). There are significant black/white differences in intercepts and slopes. Other variables explain only another 1%-2% of the variance. The strongest Pearson correlations are between changes in bone mass and changes in lean mass and log-transformed weight (r ranging from 0.62 to 0.84, p = 0.0001). We conclude that there is a significant black/white, but not male/female difference in whole body bone mass and bone density before puberty. Ethnic and gender differences in bone and body composition suggest that the lean component may contribute to a greater peak bone mass in blacks vs. whites, and perhaps in males vs. females.

Maternal assessment of infant development: associations with alcohol and drug use in pregnancy

Surveillance by parental concern has been advocated to assess whether formal child developmental testing is needed. To determine whether alcohol intake or illicit drug use in pregnancy is associated with differences in maternal perception of infant development, mothers with acknowledge alcohol and drug habits during pregnancy (N = 120) were interviewed at 11 months' postpartum, within 1 month before infant testing by use of the Bayley Scales of Infant Development. Women with heavy alcohol intake during pregnancy (> 3.5 oz absolute alcohol per week) were 15-fold more likely to overestimate their infant's mental development (P < 0.05), whereas mothers using illicit drugs were 4-fold more likely to overestimate their infant's physical development (P = 0.02). Given the frequent denial of substance abuse, we suggest that health care providers be cautious in accepting a lack of parental concern about a child's development and rely more heavily on formal testing, particularly in high-risk populations.

Modulation of atrial repolarization by site of pacing in the isolated rabbit heart

BACKGROUND

Single-site or multisite atrial pacing may reduce the incidence of atrial fibrillation in humans. The therapeutic mechanisms may include synchronization of atrial repolarization (repolarization "memory") and/or decreased dispersion of atrial repolarization. These responses have not been well documented in intact atria.

METHODS AND RESULTS

Monophasic action potential recordings were made from six atrial epicardial sites in 39 isolated perfused rabbit heart preparations during 3 hours of continuous right atrial, left atrial, or biatrial pacing. Action potential recordings obtained at times 0, 45, 90, 135, and 180 minutes were computer analyzed for activation time (AT) and 90% action potential duration (APD) at each site. No consistent relationship could be demonstrated between APD and AT at any time during atrial pacing (all P > .05). On average, left atrial APDs were longer than right atrial APDs by up to 6.3 ms at all times, regardless of the site of pacing (P < or = .05). At all times, dispersion of atrial repolarization was minimized by left atrial pacing compared with right atrial pacing (21.6 +/- 9.1 versus 32.4 +/- 15.1 ms, respectively, at time 0; P < .05). Biatrial pacing provided no further reduction in dispersion of repolarization compared with left atrial pacing (all P > .05).

CONCLUSIONS

No relationship can be demonstrated between atrial AT and APD in the isolated rabbit heart preparation. This differs from ventricular repolarization "memory," which is demonstrable under the same conditions. Left atrial APD is, on average, longer than right atrial APD, suggesting spatial heterogeneity in repolarization. Dispersion of atrial repolarization is minimized by left atrial pacing in this preparation with no further advantage to biatrial pacing.

Predicting outcome in children with severe acute respiratory failure treated with high-frequency ventilation

OBJECTIVES

a) To demonstrate the effect of high-frequency ventilation on gas exchange in children with severe acute respiratory failure unresponsive to conventional ventilation; b) to identify patients at high risk of death early after institution of high-frequency ventilation.

SETTING

Tertiary care pediatric intensive care unit in a university hospital.

DESIGN

A cross-sectional, observational study with factorial design.

PATIENTS

Thirty-one patients with severe acute respiratory failure defined as a Pao2/F1o2 of < 150 torr (< 20 kPa) with a positive end-expiratory pressure of > or = 8 cm H2O and/or Paco2 of > 60 torr (> 8 kPa) with an arterial pH < 7.25.

INTERVENTIONS

Patients received either high-frequency oscillation or jet ventilation if respiratory failure was unresponsive to conventional ventilation and if the underlying disease process was deemed reversible.

MEASUREMENTS AND MAIN RESULTS

Thirty-one children were managed with high-frequency ventilation, 11 children with jet and 20 children with oscillator. Arterial blood gases and level of ventilatory support were recorded before and at 6, 24, 48, 72, and 96 hrs after institution of high-frequency ventilation. There was an improvement in an arterial pH, Paco2, Pao2, and Pao2/FID2 6 hrs after institution of high-frequency ventilation (p < .01). This improvement, along with decreased need for oxygen, was sustained through the subsequent course. Twenty-three (74%) of 31 children treated with high-frequency ventilation survived. Survivors showed an increase in an arterial pH, Pao2, Pao2/FIO2, and a decrease in Paco2 within 6 hrs, whereas nonsurvivors did not. Oxygenation index was the best predictor of outcome. A combination of an initial oxygenation index of > 20 and failure to decrease the oxygenation index by > 20% by 6 hrs after initiation of high-frequency ventilation predicted death with 88% (7/8) sensitivity and 83% (19/23) specificity, with an odds ratio of 33 (p = .0036, 95% confidence interval 3-365).

CONCLUSIONS

In patients with potentially reversible underlying diseases resulting in severe acute respiratory failure that is unresponsive to conventional ventilation, high-frequency ventilation improves gas exchange in a rapid and sustained fashion. The magnitude of impaired oxygenation and its improvement after high-frequency ventilation can predict outcome within 6 hrs.

A new filter paper method to measure capillary blood lead level in children

OBJECTIVE

To develop and evaluate a new filter paper method to determine capillary blood lead levels accurately in children.

DESIGN

Paired comparison of lead levels determined in capillary whole blood dried on filter paper with lead levels in venous whole blood samples determined by a reference method.

SETTING

Children's Hospital of Michigan clinics, Detroit.

PATIENTS

One hundred children aged 9 months to 6 years.

INTERVENTIONS

Lead concentrations determined in capillary whole blood samples dried on filter paper were compared with concentrations measured in paired venous whole blood samples by a reference method.

MAIN OUTCOME MEASURES

Comparability of the two lead assay methods was assessed with the concordance coefficient. The sensitivity, specificity, and positive predictivity of the capillary filter paper method relative to the reference method were determined at three intervention decision concentrations of blood lead defined by the Centers for Disease Control and Prevention.

RESULTS

There was high agreement between the two assay methods, with a concordance coefficient of O.96. The capillary filter paper assay had a sensitivity of 90% and specificity of 90% for differentiating blood lead levels of 0.48 mumol/L (10 micrograms/dL) or more. Blood lead levels of 0.72 mumol/L (15 micrograms/dL) or more and 0.96 mumol/L (20 micrograms/dL) or more were identified with 98% and 94% sensitivity and 98% and 99% specificity, respectively. Positive predictivity was 93%, 98%, and 97%, respectively, at the three blood lead concentration decision points.

CONCLUSION

The capillary filter paper method for blood lead analysis described herein provides a convenient, sensitive, accurate, and inexpensive method to examine children for elevated blood lead levels.

AIDS patients' perceptions of nursing care quality

The authors propose a model, adapted from literature on quality in health care and services marketing, that identifies dimensions of quality in nursing care for persons with AIDS. In focus groups, respondents expressed concern about structural factors such as formal hospital practices, and process factors, which include nurses' knowledge of AIDS treatment and issues, their use of universal precautions, discrimination issues, expressions of empathy, and provision of health status information to the patient.

Long-term temporal patterns of ventricular tachyarrhythmias

BACKGROUND

Technological limitations have precluded investigation of long-term temporal patterns of ventricular tachyarrhythmia recurrences. Newer implantable cardioverter-defibrillators permit such analyses by accurately recording the time and date of tachycardia detections during long-term follow-up. This study tests the hypothesis that ventricular tachycardia occurrences are randomly distributed over time in individual patients.

METHODS AND RESULTS

The time and date of 727 episodes of ventricular tachyarrhythmias were recorded from the data logs of 31 patients with implantable cardioverter-defibrillators followed for a median of 177 days (range, 7 to 782 days). All patients had three or more ventricular tachycardia detections and no detections from causes other than ventricular arrhythmias. In 28 of 31 patients, the distribution of the interdetection time intervals during follow-up differed significantly (all P < .01) from an exponential model distribution of interdetection intervals that assumed that detections were equally likely to occur at any time during follow-up (random). The Kolmogorov-Smirnov goodness-of-fit test was used to compare sample and model distributions. In each patient, the nonrandom distributions resulted from a preponderance of interdetection time intervals that were shorter than predicted by the random model, resulting in a temporal clustering of arrhythmic events. The interdetection interval was < or = 1 hour and < or = 91 hours for 55% and 78% of all intervals, respectively. When only those episodes receiving shock or antitachycardia pacing therapy were analyzed, 25 of 29 patients still manifested nonrandom distributions (all P < .01). When only episodes with tachycardia rates > 240 beats per minute were analyzed, 11 of 13 patients manifested non-random distributions (all P < .01).

CONCLUSIONS

Ventricular tachycardia detections and delivered antitachycardia therapies by implantable cardioverter-defibrillators are nonrandomly distributed throughout long-term follow-up in the majority of patients. The temporal clustering of these arrhythmic events may allow preemptive antiarrhythmic therapy and should be considered in the design of therapy based on suppression of spontaneous ventricular arrhythmias to statistically derived end points.

Ownership and utilization of MR imagers in the Commonwealth of Virginia

PURPOSE

To assess distribution, operation, and ownership of magnetic resonance (MR) imagers in Virginia in 1991.

MATERIALS AND METHODS

Questionnaires regarding ownership, location, hours of operation, annual throughput, sources and amounts of revenue, and expenses were mailed to identified providers. Data, specifically regarding ownership and location, were analyzed.

RESULTS

Staff from 95% of MR facilities responded. Most facilities were located in and around major metropolitan areas. Population density per imager ranged from one per 76,000 to one per 222,000 persons. Imagers in larger metropolitan areas were operated for longer hours with higher revenues and greater expenses than were those in lower-population-density areas. Imagers owned by physicians in a position to self-refer had the highest patient throughput, the most revenue, and a much lower percentage of revenues from Medicare and Medicaid than did other ownership types.

CONCLUSION

Patient access to MR services in Virginia is inhomogeneous. Important aspects of utilization are location and ownership. Ownership by physicians who can self-refer is associated with higher use, greater overall revenues, and less service to the poor and elderly.

Circadian pattern of ventricular tachyarrhythmias in patients with implantable cardioverter-defibrillators

OBJECTIVES

This study examined the temporal patterns of ventricular tachycardia detections by implantable cardioverter-defibrillators for circadian variability.

BACKGROUND

Previous studies of circadian arrhythmia patterns have been methodologically limited by very brief observational periods. Late-generation implantable cardioverter-defibrillators accurately record the times of arrhythmia detections during unlimited follow-up.

METHODS

Forty-three patients with late-generation implantable cardioverter-defibrillators were followed up for 226 +/- 179 days (mean +/- SD). The times of all recorded episodes of ventricular tachyarrhythmias were retrieved from the data log of each device during follow-up.

RESULTS

The weighted distribution of 830 ventricular tachyarrhythmia episodes from the 43 patients fit a single harmonic sine curve model with a peak between 2 and 3 P.M. (95% confidence interval 1:13 to 4:13 P.M., R = 0.75, p < 0.05). The distributions of spontaneously terminating episodes, episodes receiving device therapy, episodes receiving shocks and episodes in the absence of antiarrhythmic therapy also fit the sine curve model (all R = 0.53 and 0.73, all p < 0.05), all with peak frequencies between 2:08 and 3:09 P.M. and 95% confidence intervals for peak frequencies between 11:38 A.M. and 5:07 P.M. Episodes recorded during continuous antiarrhythmic drug therapy did not fit the model (p > 0.05).

CONCLUSIONS

The distribution of ventricular tachyarrhythmias detected by late-generation implantable cardioverter-defibrillators follows a circadian pattern, with a peak tachycardia frequency between noon and 5 P.M. This pattern was not observed in patients receiving antiarrhythmic drug therapy. Knowledge of circadian periodicity for these events has implications for patient management.

Bradycardia during anesthesia in infants. An epidemiologic study

BACKGROUND

The frequency and morbidity of bradycardia during anesthesia in infants are not well documented. This study sought to determine the frequency of bradycardia during anesthesia in infants (0 to 1 yr) compared to that in older children, describe causes and morbidity, and identify factors that influence its frequency.

METHODS

Computerized information abstracted from 7,979 anesthetic records of patients ages 0-4 yr undergoing noncardiac surgery were examined for the presence or absence of intraoperative bradycardia. To study bradycardia in infants, 4,645 anesthetics in patients aged 0-1 yr were considered. Those with bradycardia to heart rates less than 100 beats/min were examined for causes, morbidity, and treatment of the bradycardia. For analysis of influencing factors, the frequency of bradycardia in infants was related to age, sex, race, ASA physical status, surgical site (body cavity), complexity (major or minor) and duration, type of primary anesthetist, type of supervising anesthesiologist, and anesthetic agents. Logistic regression was used to estimate the significance (P < 0.05) and odds ratios for each.

RESULTS

The frequency of bradycardia was 1.27% in the 1st yr of life, but only 0.65% in the third and 0.16% in the 4th yr, a significant difference. Causes of bradycardia in infants included disease or surgery in 35%, the dose of inhalation agent in 35%, and hypoxemia in 22%. Morbidity included hypotension in 30%, asystole or ventricular fibrillation in 10%, and death in 8%. Treatment involved epinephrine in 30% and chest compression in 25%. Associated factors included an ASA physical status of 3-5 (vs. 1 or 2) and longer (vs. shorter) surgery. Bradycardia was less than half as likely when the supervising anesthesiologist was a member of the Pediatric Anesthesia Service as with other anesthesiologists (P < 0.001).

CONCLUSIONS

Bradycardia is more frequent in infants undergoing anesthesia compared to older children and is associated with substantial morbidity. It is more likely in sicker infants undergoing prolonged surgery and less likely when a pediatric anesthesiologist is present.

Modulation of the QT interval: effects of graded exercise and reflex cardiovascular stimulation

During exercise, as heart rate (HR) increases, the QT interval of the electrocardiogram shortens. The mechanism(s) involved in this QT shortening has not been clearly defined. To distinguish the influence of increased circulating catecholamines from myocardial efferent stimulation, the relationship between HR and QT interval was investigated during exercise and cardiovascular reflex stimulation in cardiac transplant patients and normal control subjects. Because of cardiac denervation, increases in HR in these patients are solely due to circulating catecholamines and thus allow isolation of their effect on the QT interval. Twenty-one cardiac transplant patients were studied and compared with 16 normal control subjects. The QT-HR relationship was determined according to an exponential model during treadmill exercise in both groups [QT = 0.12 + 0.492e(-0.008.HR) and QT = 0.12 + 0.459e(-0.007.HR) in normal subjects and transplant patients, respectively] and was statistically similar between groups, suggesting similar QT interval shortening in both groups. During cold pressor and Valsalva maneuvers, HR increased significantly in normal subjects only, whereas QT interval changed minimally in both groups. These results suggest that during exercise the QT interval is influenced predominantly by increases in circulating catecholamines rather than by neurally mediated reflex autonomic changes.

Creation of state-level Medicare database for healthcare evaluation applications

The Health Care Quality Improvement Initiative (HCQII) of the Health Care Financing Administration (HCFA) calls for Professional Review Organizations (PROs) to undertake pattern analysis of large administrative datasets for the purposes of quality of care assessment. The limitations of such administrative databases (primarily the MEDPAR file and derivatives thereof) include impoverished information regarding clinical attributes of Medicare enrollees and the process and outcome of their healthcare. This paper describes preliminary efforts to address this problem by the creation of a database, the PRO Concatenated Database (PCD), from the pooled implicit judgment review data of four Peer Review Organizations (PROs). The data elements comprising the PCD were carefully selected to provide important information regarding quality and appropriateness of care. Preliminary inter-state comparative studies employing the PCD are discussed. A method is also described by which the analytical power of state-level databases may be enhanced by linkage to state-level Modeled MEDPAR data which are issued by HCFA and contain patient-level risk-adjusted mortality data. This approach to the acquisition of data whose clinical content is enriched may prove to be particularly useful to the PRO community during the pattern analysis phase of the HCQII. Such analyses will evolve into more detailed studies involving primary data collection followed by dissemination of the results to local healthcare providers. In this manner, the PCD may facilitate rapid feedback regarding the effectiveness of healthcare delivery to the local community.

Extracorporeal membrane oxygenation and early-onset group B streptococcal sepsis

Recently, extracorporeal membrane oxygenation (ECMO) has been used as rescue therapy for newborns with overwhelming early-onset group B streptococcal sepsis. To determine which clinical factors best predict mortality and to evaluate the outcome of this therapy, a retrospective examination of the clinical course and outcome of ECMO-eligible newborns with early-onset group B streptococcal sepsis was undertaken. The study period was divided into two phases based on when ECMO was initially used at Kosair Children's Hospital as therapy for septic neonates. Phase 1 (pre-ECMO) was the period from January 1, 1982, through June 15, 1986, and phase 2 (ECMO) from June 16, 1986, through December 31, 1989. Newborns with gestational age greater than or equal to 34 weeks, birth weight greater than or equal to 2000 g, and evidence of early-onset group B streptococcal sepsis were eligible for study. Only newborns who received mechanical ventilation were evaluated. Sixteen patients from phase 1 met the above criteria. Of those, 10 exhibited no sign of hypotension and all survived. Of the 6 patients with hypotension, 3 died. Forty patients were identified from phase 2. Seven patients remained normotensive and all survived. Thirty-three patients were hypotensive, of which 15 received ECMO and 13 survived. Of the 18 who did not receive ECMO, 7 died. Regarding all hypotensive newborns, those who did not receive ECMO had a trend toward lower survival (P less than .06) and were more likely to die if they were of lower birth weight, manifested a persistent acidosis (pH less than or equal to 7.25), and had an absolute neutrophil count less than 500 cells/mm3.(ABSTRACT TRUNCATED AT 250 WORDS)

Cholinesterase inhibition in the scopolamine model of dementia

Scopolamine produces a satisfactory model of the attentional and secondary memory deficits seen in Alzheimer's disease (AD) that can be used to screen compounds for potential therapeutic usefulness. Physostigmine, which is known to enhance memory in AD, produced marked and widespread antagonism of the scopolamine-induced impairments, indicating the sensitivity of the model and establishing its relevance for the clinical situation. HP 029, a novel anticholinesterase, also exhibited widespread potency in the model, and in an international trial with patients with AD, it subsequently showed improvement on similar measures, demonstrating the predictive use of the scopolamine model.

Effect of extracorporeal membrane oxygenation on leukocyte function in neonates

The impact of extracorporeal membrane oxygenation (ECMO) on neonatal leukocyte content and function was examined in six patients. Patients were treated with ECMO for a mean of 134 h (range 44-246 h). Absolute neutrophil counts decreased from 14679 +/- 2291/mm3 to 7791 +/- 1672/mm3 after 2 h of ECMO. However, neutrophil phagocytosis and oxidative burst remained unchanged during the first 48 h of bypass. Monocyte counts also decreased during bypass, and at times were undetectable in 50% of patients. Monocyte HLA-DR content was decreased compared to normal cord blood prior to initiation of ECMO, and remained low throughout ECMO. However, the content increased significantly after termination of bypass. Plasma C3a levels increased transiently, paralleled by an increase in neutrophil CR3 expression. While moribund infants had some impairment of host defenses prior to ECMO, there was no further impact of ECMO per se on the parameters measured, other than transient complement activation and decreased monocyte counts.

HLA antigens in lichen sclerosus et atrophicus

Several reports have found conflicting data regarding the association between lichen sclerosus et atrophicus (LSA) and HLA types. Association with HLA-A31 and -B40 has been noted, whereas another report found no correlation. We are the first to specifically examine HLA types in white patients in the United States. We have found a significant association between LSA and HLA-A29 and -B44 individually and an even stronger association with the combination of A29 and B44. A review of previous LSA-HLA studies, as well as several reports of HLA typing in familial LSA, is discussed, with consideration given to possible reasons for the discrepancies among the various studies.