An audit of adverse events in children sedated with chloral hydrate or propofol during imaging studies

We examined records of sedations provided by the paediatric anaesthesiology staff for 455 children (ages 1 mo-17 yr) undergoing MRI or CT scans at our institution over a twelve-month period with regard to the monitoring of adverse events: excessive sedation, agitation, vomiting, hypoxaemia, and major airway compromise. One hundred-and-thirty-one patients (29%) received chloral hydrate; 324 patients (71%) received propofol. All patients were monitored with continuous noninvasive pulse oximetry and received supplemental oxygen via nasal cannulae. Of the patients who received chloral hydrate, 64 (49%) were over one year of age; of the patients who received propofol, 318 (98%) were one year of age or older. In the chloral hydrate group, 23 patients (19%) were deemed excessively sedated and four patients (3%) were agitated; no patients in the propofol group experienced any of the adverse outcomes reviewed. Furthermore, no patients in either group had significant airway compromise and none was admitted to the hospital as a result of the sedation.     

Direct and Telemetered Lead Impedance

Objectives: We undertook this study to determine whether telemetered lead impedance measurements (LIM) can be correlated with direct LIM and to determine the stability of LIM over time when measured directly and via telemetry. Methods: Direct LIM and telemetered LIM were measured in 91 patients; 101 leads during initial implantation and 40 leads during pulse generator replacement. Differences in direct LIM measured during initial implant and pulse generator replacement (direct-direct) were compared in 41 patients (28 atrial leads and 37 ventricular leads). The stability of telemetered LIM obtained immediately postoperatively, at 1 month and 1 year, postimplantation was assessed in 50 patients (23 atrial and 49 ventricular leads). Results: In atrial leads acute direct LIM was 633.9 ± 18.4 Ω versus 575.8 ± 18.5 Ω for telemetered LIM (r = 0.58), and chronic direct LIM was 670.9 ± 49.3 Ω versus 607.0 ± 36.3 Ω for telemetered LIM (r = 0.87). In ventricular leads acute direct LIM was 747.3 ± 16.9 Ω and 684.7 ± 16.4 Ω for telemetered LIM (r = 0.69), and chronic direct LIM was 674.8 ± 29.9 Ω and 625.2 ± 28.5 Ω for telemetered LIM (r = 0.68). The mean direct–direct UM rose 124 Ω (P < 0.001) in atrial leads and 10 Ω (P = NS) in ventricular leads. Telemetered LIM for atrial leads was 581.0 ± 27.6 Ω immediately postimplantation compared to 625.7 ± 34.8 Ω at 1 month and 754.1 ± 43.0 Ω at 1 year. Telemetered LIM for ventricular leads was 661.3 ± 17.5 Ω at implant, 684.6 ± 20.7 Ω at 1 month and 724.7 ± 22.7 Ω at 1 year. Conclusions: There is a good but limited correlation between direct and telemetered LIM. Mean direct LIM obtained at initial implantation is similar to that measured at pulse generator replacement. The telemetered LIM is stable over the first month postimplantation but tends to rise during the first year of follow-up and substantial changes in impedance are not uncommon in individuals with normal function. There is a tendency for LIM to rise with lead maturation. If telemetered LIM is to be followed over time, a baseline telemetered value should be obtained immediately postoperatively.     

The structure of human skin collagen as studied with the electron microscope

1. The structure of the collagen fibrils of normal human skin corium has been investigated with the electron microscope. 2. Under the conditions of observation the fibrils ranged in width from about 700 to 1,400 A with 1,000 A as the value occurring most frequently. They showed little tendency to fray longitudinally as is characteristic of tendon fibrils; when fracture of fibrils occurred it was usually in planes transverse to the axis. 3. The axial repeating periods observed in fibrils stained with phosphotungstic acid or shadowed with chromium or platinum range from about 500 to 800 A, the maximum occurring between 620 and 660 A. The average period in fibrils from infant skin does not differ significantly from that of adult and aged skin. 4. Depending on conditions of preparation, intraperiod fine structure, in the form of cross-bands, was observed in varying detail. The most detailed pattern commonly observed contains six bands of characteristic density and position. 5. Shadowed plastic replicas of dried collagen fibrils reproduce much of the structure commonly seen in shadowed fibrils. Replicas of moist fibrils show considerably less surface contouring than do dried fibrils. Replicas from smears of connective tissue fragments on glass show detailed structure, indicating the feasibility of applying this technique to biopsy material. 6. Infant skin differs from adult skin in having considerably greater amounts of amorphous material, little of which is strongly adherent to the collagen fibrils.     

Prediction of Arrhythmic Events After Acute Myocardial Infarction Using Two Methods for Late Potentials Recording

One hundred consecutive patients recovering from an acute myocardiai infarction underwent, prior to home discharge, signal-averaged electrocardiography (ECG), left ventriculography. and 24-hour Holter ECG recording. The signal-averaged ECG was recorded and analyzed using two procedures: the orthogonal bipolar XYZ lead configuration with a bidirectional filter: and a precordial unipolar lead configuration with a uonrecursive digital filter. An abnormal signal-averaged ECG was seen in 40% of patients with the XYZ system and in 30% of patients in the precordial method, abnormal ejection fraction (< 40%) in 24% of patients and high grade ectopy activity in 22%. During the 24-month follow-up period, 12 patients (12%) had an arrhythmic event defined as either sudden death (11 patients) or sustained ventricular tachycardia (1 patient). Neither the signal-averaged ECG with the XYZ configuration, the abnormal ejection fraction, nor the high grade ectopy were able to statistically predict a higher arrhythmic event rate. The signal-averaged ECG with the precordial configuration was able to statistically predict a higher arrhythmic event rate, P < 0.03; odds ratio = 3.96. The combination of the orthogonal XYZ configuration signal-averaged ECG with the ejection fraction (P < 0.01, odds ralio = 7.33), or with ejection fraction and Holter monitoring (P < 0.06. odds ratio = 6.17) was able to predict a higher arrhythmic event rate. The combination of the precordial configuration signal-averaged ECG with the ejection fraction (P < 0.002, odds ratio = 14.4), or with ejection fraction and Holter monitoring (P < 0.06. odds ratio =10) was able to better predict a higher arrhythmic event rate. The combination of a normal or abnormal signal-averaged ECG and ejection fraction gave a sensitivity, specificity, positive, or negative value prediction of arrhythmic events of 60%, 90.6%, 37.5%, and 96%, respectively. It must be emphasized that the number of arrhythmic events during the 2-year follow-up was small and further study is required to determine the true predictive value of each method for arrhythmic events.     

Anti-neutrophil cytoplasmic antibodies (ANCA) directed against bactericidal/permeability increasing protein (BPI): a new seromarker for inflammatory bowel disease and associated disorders

It was our purpose to determine the immunodiagnostic value of ANCA directed against BPI in diseases known to be associated with ANCA, such as ANCA-associated vasculitides, inflammatory bowel disease (IBD) and the associated condition primary sclerosing cholangitis. The immunoreactivity of recombinant BPI (rBPI) was established in order to develop an ELISA specific for rBPI. By means of this assay, BPI-ANCA were assessed in sera of 178 patients with IBD or the associated disorder primary sclerosing cholangitis, 112 patients with ANCA-associated vasculitides, and in sera of 182 disease and 140 healthy controls. BPI-ANCA were found to be closely associated with IBD and primary sclerosing cholangitis (34% and 44% of ANCA-positive sera, respectively). By contrast, BPI-ANCA positivity was low (<10%) in the double-negative sera of patients with ANCA-associated vasculitides and in disease and healthy controls. BPI-ANCA appear to constitute an important marker for IBD and primary sclerosing cholangitis, but not for the ANCA-associated vasculitides.     

The Effect of Saline Iontophoresis on Skin Integrity in Human Volunteers: I. Methodology and Reproducibility

This study, conducted in 36 human volunteers, was an evaluationof the effects of saline iontophoresis on skin temperature,irritation, and barrier function. The major objectives wereto assess the effects of low-level ionic currents, to validatethe proposed methodology of assessment, and to establish reproducibilityin repeated saline iontophoresis applications. This was thefirst of a multistage study designed to assess the safety of24-hr saline iontophoresis episodes at selected currents andcurrent densities. Since an iontophoresis patch challenges theskin harrier both by occluding the skin surface and by passingionic current through the skin, the experimental protocol wasdesigned to permit measurement of the contribution of each ofthese processes to the overall response. In this first stagewe investigated the effect of 10 min of current delivery, at0.1 mA/cm² on a 1-cm² area patch and 0.2 mA/cm² on a 6.5-cm²area patch compared to unpowered control patches. Twelve subjectswere tested under each condition on two separate occasions toexamine reproducibility of the response variable measurements.A further 12 subjects were tested once under the 0.2 mA/cm 6.5-cm2condition. Skin irritation was evaluated via repeated measurementsof transepidermal water loss, capacitance, skin temperature,skin color, and a visual scoring system, before the iontophoresisepisode and after patch removal. No damage to skin harrier functionin terms of skin-water loss or skin-water content was detected.Slight, subclinical, short-lasting erythema was observed forboth conditions. Assessment of correlation coefficients showedhighly statistically significant indications of reproducibilityfor all five response variables measured. The experimental design,in combination with a repeated measures analysis, provided clearseparation of the occlusion and ionic current components ofthe iontophoretic patch challenge. Further, the repeated measuresanalysis gave a highly sensitive assessment of skin irritationand resolution after patch removal. We conclude that the experimentalmethodology is appropriate for assessing possible changes inskin integrity resulting from saline iontophoresis under similaroperating conditions for longer durations and for other skinchallenges from which a subclinical response is expected.