Cardiac rhythm disturbances among children with idiopathic congenital central hypoventilation syndrome.

The objective of this study was to determine whether subjects with congenital central hypoventilation syndrome (CCHS) had an increased frequency of cardiac arrhythmias and decreased heart rate variability when compared to subjects without a known deficit in control of breathing, and that these abnormalities would be exaggerated by anesthesia. Continuous ambulatory Holter recordings were obtained in patients with CCHS and compared to two otherwise healthy control groups without a deficit in control of breathing: one with an intact airway (n = 11) and a second group with a tracheostomy (n = 6). Holter recordings were obtained before, during (under general anesthesia), and after bronchoscopy. Fourteen children with CCHS (age: 9.3 +/- 4.4 years mean +/- S.D.) were studied, and 7 underwent bronchoscopy. Seventeen control children were studied (age 6.6 +/- 3.6 years): 11 without a tracheostomy, and 6 with a tracheostomy who also underwent bronchoscopy. Maximum heart rate during baseline recording was significantly lower in the CCHS subjects as compared to controls (P = 0.0001). At baseline the difference in the number of arrhythmias/24 hr/subject in all CCHS vs. all control subjects was significant (P = 0.0002); for the subjects who had bronchoscopy, CCHS vs. control, the difference was also significant (P = 0.03). In addition, there was a significant decrease in the number of events/24 hr/subject among the CCHS subjects between baseline and post-bronchoscopy (P = 0.0288). The predominant arrhythmias were sinus bradycardia and transient asystole. The longest asystole in a CCHS subject was 6.50 sec, and in a control subject, 1.42 sec (at baseline the means of the longest asystole were 2.69 +/- 1.4 vs. 1.24 +/- 0.13; P = 0.003 in the CCHS vs. control groups). Other indices of heart rate variability were significantly reduced in the CCHS subjects (P < 0.05). These results substantiate our hypothesis that subjects with CCHS have more arrhythmias than controls, an increased frequency of bradyarrhythmias, and decreased cyclical sinus arrhythmia.

Control of intraocular pressure elevations after argon laser trabeculoplasty: comparison of brimonidine 0.2% to apraclonidine 1.0%.

OBJECTIVE: To determine whether brimonidine 0.2% can control intraocular pressure (IOP) spikes as well as apraclonidine 1.0% can in those patients undergoing argon laser trabeculoplasty (ALT). DESIGN: Prospective, randomized, double-masked, clinical trial. PARTICIPANTS: A total of 56 eyes of 41 patients with open-angle glaucoma or ocular hypertension were entered in the study; 46 eyes of 41 patients were eventually used for the final analysis. INTERVENTION: Patients were randomized to receive either brimonidine 0.2% or apraclonidine 1.0% before and after 360 degrees ALT. Both patient and physician were masked as to which agent each patient received. MAIN OUTCOME MEASURES: Intraocular pressure measurements were recorded before surgery and at 1, 2, and 4 hours after surgery. The difference between the preoperative IOP (baseline) and the highest recorded postoperative IOP was recorded as the maximum IOP change. The mean of the maximum IOP change for each group was analyzed using a two-sample, one-tailed t test. RESULTS: The mean of the maximum IOP change in the brimonidine 0.2% group was -2.6+/-3.6 mmHg, and the mean for the apraclonidine 1.0% group was -2.3+/-3.7 mmHg (P = 0.8). No patient had a pressure spike greater than 10 mmHg. CONCLUSIONS: Brimonidine 0.2% appears to be as effective as apraclonidine 1.0% in preventing IOP spikes after argon laser trabeculoplasty.

Nevoid basal cell carcinoma syndrome in a black child.

Nevoid basal cell carcinoma syndrome (NBCCS) is rare in black persons. We describe an 11-year-old black boy with NBCCS who presented with exotropia and a painful, expanding, cystic mass in the left posterior alveolar ridge. Further examination revealed odontogenic keratocysts with palmar and plantar pitting. Less than 5% of reported patients with NBCCS are black. To our knowledge, this is the first report of a black patient with NBCCS presenting with exotropia and an impacted molar displaced into the orbit by an odontogenic keratocyst.

The pediatric cardiology pharmacopoeia.

Keeping up with a rapidly growing list of medications has always been a breathtaking and, at times, impossible task to master. Contrary to common belief, the enormity of keeping abreast with the more recently developed medications is not a modern phenomenon resulting from the great technological advances of the past few years, but an ongoing struggle spanning the latter half of this century. It appears that there are more drugs to use than to know how, when, or what to do with them. This sentiment was expressed in 1973 by the editors of Martindale's The Extra Pharmacopoeia, twenty-sixth edition [3]: "The unprecedented rate at which our knowledge of medicine and pharmacy is advancing makes it a formidable challenge to provide within a single volume an up-to-date source of basic information on the properties and uses of the many drugs in current use." In this article, a review of the medications currently used in the management of children with heart diseases is presented. The medications have been collected in groups based upon their pharmacological actions: Antiarrhythmic, antihypertensive, diuretics, sedatives and miscellaneous agents. Within each group the agents are listed alphabetically using chemical names. We attempted to include as many drugs as thought to be of relevance to the team of health practitioners involved in the care of children with cardiac problems. Various routes of administration are presented, some of which have been infrequently described in the pediatric literature, such as continuous infusion of diuretic agents [22]. The dosing ranges were adopted from many sources [1, 5, 8, 9, 17-19, 22, 23, 26], and we sought to include the widest ranges of dosages published. All dosages listed in Table 1 are quantitated per dose and not per day. This approach was adopted as it reduces calculations and the potential for medication errors.

Halothane enhances pulmonary artery endothelial eicosanoid release.

To determine whether anesthetics alter endothelial eicosanoid release, cultured bovine pulmonary artery endothelial cells were studied during constant flow and pressure perfusion at two oxygen tensions (hypoxia, 50 +/- 2 mm Hg; normoxia, 144 +/- 5 mm Hg; mean +/- SEM) with and without 1% halothane. Endothelialized microcarriers containing approximately 5 x 10(6) cells were loaded into cartridges and perfused (3 mL/min) with Krebs' solution (pH 7.4, at 37 degrees C) equilibrated with each gas mixture. Eicosanoids (6-keto prostaglandin F1 alpha, thromboxane B2, and total peptidoleukotrienes [C4, D4, E4, F4]) were measured by radioimmunoassay and quantified per gram of cellular protein per minute. Eicosanoid release did not vary over time. The 6-keto prostaglandin F1 alpha release increased during hypoxia (normoxia 291 +/- 27 vs hypoxia 395 +/- 35 ng.min-1 x g protein-1; P < 0.01). Halothane (H) increased release of each eicosanoid during both normoxia and hypoxia: 6-keto prostaglandin F1 alpha-normoxia 291 +/- 27 versus normoxia + H 356 +/- 32 ng.min-1 x g protein-1, hypoxia 395 +/- 35 versus hypoxia + H 464 +/- 40 ng.min-1 x g protein-1, P < 0.05; thromboxane B2-normoxia 19 +/- 2 versus normoxia + H26 +/- 2 ng.min-1 x g protein-1, hypoxia 20 +/- 2 versus hypoxia + H 38 +/- 5 ng.min-1 x g protein-1, P < 0.001; leukotriene-normoxia 363 +/- 35 versus normoxia + H 489 +/- 52 ng.min-1 x g protein-1, hypoxia 329 +/- 29 versus hypoxia + H 455 +/- 39 ng.min-1 x g protein-1, P = 0.001.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute hypoxia alters eicosanoid production of perfused pulmonary artery endothelial cells in culture.

Hypoxia alters vascular tone which regulates regional blood flow in the pulmonary circulation. Endothelial derived eicosanoids alter vascular tone and blood flow and have been implicated as modulators of hypoxic pulmonary vasoconstriction. Eicosanoid production was measured in cultured bovine pulmonary endothelial cells during constant flow and pressure perfusion at two oxygen tensions (hypoxia: 4% O2, 5% CO2, 91% N2; normoxia: 21% O2, 5% CO2, 74% N2). Endothelial cells were grown to confluence on microcarrier beads. Cell cartridges (N = 8) containing 2 ml of microcarrier beads (congruent to 5 x 10(6) cells) were constantly perfused (3 ml/min) with Krebs' solutions (pH 7.4, T 37 degrees C) equilibrated with each gas mixture. After a ten minute equilibration period, lipids were extracted (C18 Sep Pak) from twenty minute aliquots of perfusate over three hours (nine aliquots per cartridge). Eicosanoids (6-keto PGF1 alpha; TXB2; and total leukotriene [LT - LTC4, LTD4, LTE4, LTF4]) were assayed by radioimmunoassay. Eicosanoid production did not vary over time. 6-keto PGF1 alpha production was increased during hypoxia (normoxia 291 +/- 27 vs hypoxia 395 +/- 35 ng/min/gm protein; p less than 0.01). Thromboxane production (normoxia 19 +/- 2 vs hypoxia 20 +/- 2 ng/min/gm protein) and total leukotriene production (normoxia 363 +/- 35 vs hypoxia 329 +/- 29 ng/min/gm protein) did not change with hypoxia. These data demonstrated that oxygen increased endothelial prostacyclin production but did not effect thromboxane or leukotriene production.

Comparison of nasal brush and nasopharyngeal aspirate techniques in obtaining specimens for detection of respiratory syncytial viral antigen by immunofluorescence.

Diagnosis of respiratory syncytial virus by antigen detection is dependent on obtaining adequate respiratory epithelial cells. Two specimen collection methods, nasopharyngeal aspiration (NPA) and nasal brushing (NB), were compared. Thirty-two pediatric patients with presumed viral pneumonia or bronchiolitis (34 episodes) had both NPA and NB performed. Of 34 specimens 15 were culture-positive for respiratory syncytial virus. Of these 12 NPA samples and 10 NB samples had viral inclusions by immunofluorescent antibody staining (IFA). Of culture-negative samples, 1 of 17 NB was positive by IFA. One specimen obtained by NB had too few cells to read by the IFA method. Sensitivity and specificity were 80 and 100% for NPA and 67 and 94% for NB. Total respiratory cells and IFA-positive cells (classified as few, moderate, or many) were greater with NPA; however, NB was also an effective procedure and was better tolerated by children, less expensive and easier to perform.

Effects of elevated P02 upon tracheal explants.

Time-dependent effects of elevated PO2 upon hamster tracheal rings in culture were examined. Ciliary activity of rings in 0.20 and 0.40 O2 remained stable for 144 h. Ciliary activity decreased 25% following 120 h exposure to 0.60 O2 and 50% within 72 h exposure to 0.95 O2. Ciliostasis occurred by 144 h at 0.95 O2. [3H]Leucine uptake progressively decreased during 24 to 144 h exposure to 0.40, 0.60, and 0.95 O2 when compared to 0.20 O2. Tracheal explants incubated for 6 days under 0.20 and 0.40 O2 had intact epithelial surface with abundant cilia, and no mucus present (scanning electron microscopy). Explants incubated under 0.60 O2 contained mucus globules by 3 days. Incubation in 0.95 O2 resulted in mucus globules within 3 days and epithelial sloughing, loss of cilia, and increased mucus globules within 6 days. Time and O2 dependent increases in nuclear atypia, leukocytic infiltration into submucosal area, and focal flattening of pseudostratified ciliated epithelium were observed (light microscopy). These changes progressed following 6 days' exposure to 0.95 O2 to complete loss of normal epithelium, with broken-up, epithelial cells along the tracheal lumen.