The relationship of HIV status, type of coagulation disorder, and school absenteeism to cognition, educational performance, mood, and behavior of boys with hemophilia.

Psychological and educational data were analyzed for all school-aged males with hemophilia at the Hemophilia Center of Central Pennsylvania (N = 66). Mean IQ (113.5) was higher than normal, and 2.4 times as many boys with hemophilia were enrolled in gifted programming than is the state average for boys. However, there was a disproportionately high prevalence of attention-deficit/hyperactivity disorder (ADHD; 28.3%), learning disability (LD; 15.8%), and graphomotor weakness. These were not significantly associated with HIV status or type and severity of coagulation disorder. School absenteeism was high but was not significantly related to academic achievement, IQ/achievement discrepancy, need for educational intervention, or diagnosis of ADHD or LD.

Nocturnal asthma therapy. Inhaled bitolterol versus sustained-release theophylline.

Many asthmatics complain of increased symptoms, awakenings, and need for additional medications during the sleeping hours. Sustained-release theophylline (THEO) may be superior to conventional inhaled bronchodilators in preventing nocturnal asthma symptoms and the early morning decrement in lung function common to this population. However, recent studies have demonstrated that THEO may delay sleep onset and perturb sleep stage distribution. No previous study has evaluated electroencephalographic, cardiac, and gas exchange indices during sleep in asthmatics treated with THEO compared with a long-acting inhaled beta 2-agonist. The study goals were to determine if theophylline perturbed sleep when compared with beta 2-agonists and to determine which agent achieved best control of daytime and nocturnal pulmonary symptoms and lung dysfunction. We evaluated 26 subjects with mild to moderate asthma and a history of frequent nocturnal symptoms who previously demonstrated decrements in AM lung function. THEO was compared with 3 puffs every 8 h (6 A.M., 2 P.M., and 10 P.M.) of bitolterol (BITOL), a long-acting beta 2-agonist, in a randomized, double-blind, placebo-controlled cross-over study. Each drug was administered for a 2-wk period ending with two consecutive nights of sleep evaluation followed by cross-over to the alternate drug regimen. During THEO administration, plasma concentrations on awakening were 11.4 +/- 0.69 micrograms/ml as compared with 0.00 micrograms/ml during BITOL. THEO was not found to disrupt sleep as sleep latency, total sleep time, percentage of total sleep time spent in Stages 1, 2, and 3/4 and in REM sleep were similar during each regimen.(ABSTRACT TRUNCATED AT 250 WORDS)

Prediction of successful ventilator weaning using airway occlusion pressure and hypercapnic challenge.

We studied eleven patients during 14 attempts at weaning from mechanical ventilation to determine whether central ventilatory drive, measured as airway occlusion pressure 0.1 s after onset of inspiration (P 0.1), during spontaneous breathing before and during a brief hypercapnic challenge, could accurately predict the success or failure of the attempt. All patients were recovering from acute respiratory failure and could breathe spontaneously for 20 minutes on a T-piece but were judged clinically to be marginal weaning candidates. Minute ventilation (VI) and P 0.1 were measured while breathing spontaneously and were repeated during a hypercapnic challenge that raised end-tidal PCO2 approximately 10 mm Hg. Seven of the 14 weaning attempts were unsuccessful, requiring reinstitution of mechanical ventilation. Although the failure group had lower mean maximum inspiratory force and higher spontaneous respiratory rate, no threshold value separated the failure from the success group. Ventilation increased more during hypercapnic challenge in those patients whose weaning attempt was successful, but overlap of results between the two groups rendered this test inaccurate for predicting weaning success. In contrast, successfully weaned patients had greater augmentation of P 0.1 during hypercapnia, expressed as the ratio of P 0.1 during CO2-stimulated to P 0.1 during baseline values, than did those who failed weaning (p less than 0.005). This ratio succeeded, and was thus both specific and sensitive as a predictor of successful weaning from mechanical ventilation in these patients.

Breathing during sleep in stable asthmatic subjects. Influence of inhaled bronchodilators.

The bronchoconstriction of asthma displays a circadian rhythm with exacerbations often occurring in the early morning hours. Gas exchange abnormalities during sleep in patients with severe asthma have been documented; however, the influence of sleep on gas exchange in the asthmatic with few or no daytime or nocturnal symptoms is poorly understood. To determine if abnormalities in oxygenation might occur during sleep, we studied 12 stable adult asthmatic patients with reversible airflow obstruction during sleep on three consecutive nights, with night 1 being for acclimatization. On test nights 2 and 3, the subjects received, in random double-blind fashion, either inhaled fenoterol or its placebo. Spirometry was performed before and after bronchodilator treatment and on the next morning. The mean FEV1 was 63 percent predicted before treatment. There was significant (p less than 0.05) improvement in FEV1 on fenoterol night after treatment which was also present the next morning. Mean prefenoterol FEV1 was 2.04 +/- .15 (SEM) and increased to 2.61 +/- .17 after the bronchodilator. The mean morning FEV1 was 2.27 +/- .20. Mean preplacebo FEV1 was 2.07 +/- .12 and did not change significantly with placebo bronchodilator. Sleep analysis demonstrated no significant differences in total sleep time or duration of oxyhemoglobin desaturation between nights. The incidence of sleep disordered breathing was very low (0.14 apneas/hour). The frequency of apneas and hypopneas did not change significantly with treatment. Two of the 12 subjects experienced an asthma attack on placebo night which did not recur following active bronchodilator administration. We conclude that stable asthmatic patients with few nocturnal complaints have a low frequency of disordered breathing and desaturation events during sleep.

Transient oxygen desaturation following radiographic contrast medium administration.

To determine if angiography results in arterial oxygen desaturation, we prospectively studied 40 clinically stable patients undergoing arterial angiography. Arterial oxygen saturation (Sao2) was monitored before, during, and for at least three minutes after contrast medium injection. The mean (+/- SEM) Sao2 was 94.2% +/- 0.39% before injection and fell to 92.6% +/- 0.66% following injection. Eleven patients (28%) demonstrated a decrease in Sao2 of more than 3%, with six (15%) having a postinjection Sao2 of less than 90%. To determine if the vascular route of injected contrast medium influenced the subsequent level of oxygenation, we similarly evaluated the Sao2 of 20 consecutive patients undergoing venous angiography. The Sao2 was 94.2% +/- 0.33% before contrast medium injection and fell to 92.5% +/- 0.78% following injection. Six patients (30%) experienced a fall in Sao2 of more than 3%, with four (20%) having a postinjection Sao2 of less than 90%. We conclude that arterial oxygen desaturation occurs frequently in patients undergoing angiography.

The effect of positional changes on oxygenation in patients with pleural effusions.

In unilateral parenchymal pulmonary disease, arterial oxygenation decreases when the patient is positioned such that the abnormal lung is dependent; however, few studies have evaluated the effect of the body position on oxygenation in patients with unilateral or asymmetric pleural effusions. To our knowledge, no previous study has evaluated the possible transient effects of changing position on the level of arterial oxygen saturation (SaO2) in such patients. Accordingly, we studied ten normoxic patients spontaneously breathing room air, who had asymmetric pleural effusions as documented by chest x-ray film and physical examination. We monitored pulse, respiratory rate, and blood pressure every five minutes and SaO2 by ear oximetry continuously while patients were in the following positions: sitting; supine; and left and right lateral decubitus. The mean SaO2 was 95 percent and 94.3 percent in the sitting and supine positions, respectively. Mean SaO2 fell to 93.4 percent when the patients were positioned so that the side with the largest pleural effusion was dependent. When the side with the pleural effusion was down, the mean SaO2 was significantly lower than in either the sitting position or with the side with the pleural effusion up. We could find no significant relationship between the size of the pleural effusion and the amount of arterial oxygen desaturation. We conclude that there is a decrease in SaO2 in normoxic patients when the side with the larger pleural effusion is dependent; however, this decreased SaO2 does not appear to be clinically significant in patients with normal SaO2.