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Biomedical subjects

D P Heaf

Publications and source records attributed to D P Heaf.

35 records · Page 2Linked to original sources
PubMed1989

Selective histamine blockade in childhood asthma; the effect of terfenadine on resting bronchial tone and exercise induced bronchoconstriction.

The orally active histamine H1 blocker terfenadine was investigated for its effect on resting bronchial tone and exercise induced bronchoconstriction in 20 asthmatic children by a double blind placebo controlled study. Terfenadine produced acute broncholidation with an average 32% improvement in FEV1 by 3 h. After exercise challenge terfenadine partially inhibited exercise induced bronchoconstriction. The maximum fall in PEFR after exercise was reduced from 32% after placebo to 21.5% after terfenadine. These results suggest that asthmatic children have background resting 'histamine tone' that is reversible by histamine H1 blockage.

Adolescent↗
PubMed1989

Recurrent accident and emergency department attendance for acute asthma in children.

Asthmatic children aged over 5 years making repeated visits to the accident and emergency department of a children's hospital were compared prospectively, on the basis of a clinical questionnaire and pulmonary function tests, with a control group of outpatients with asthma to find the reasons for their repeated attendance. Recurrent attenders (n = 145) had more severe asthma than control subjects (n = 118), with greater airway obstruction at rest (FEV1 79% v 85% predicted) and bronchial lability (47% v 38%). Significantly more of the "emergency" group used pressurised aerosols and fewer dry powder inhalers to administer bronchodilators. There were no differences in prophylactic treatment. Seventy one per cent of parents in the emergency group had feared that their child would die during an attack, compared with 56% of control subjects. Eighty one per cent of children were self referred to the accident and emergency department. Most parents had found hospital to be the quickest means of obtaining treatment in an emergency. There were no differences between the two groups in parents' knowledge about asthma, home conditions, or social disadvantage. Although children who repeatedly attend hospital accident and emergency departments for treatment of acute attacks have more severe asthma than controls and show some deficiencies in treatment, the major determinant of attendance appeared to be the parents' conviction that appropriate treatment could not be obtained elsewhere.

Acute Disease↗
PubMed1989

Accident and emergency department attendance by asthmatic children.

Attendances at the accident and emergency department of a children's hospital for treatment of acute asthma were studied for one year to determine the characteristics of the children attending and their management. Eight hundred and twenty children, median age 5.5 years, made 1389 visits. Records were available from 1046 visits. Clinical information and assessment of the severity of the attack in the department was often inadequate. Peak flow records were available for 366 (35%). Attendances were most frequent in September and during the evening, but there was no significant day to day variation. Eight hundred and three children (78%) were self referred. Before attendance 962 (92%) had used a bronchodilator, including nebulised salbutamol (11%); 2% had taken prednisolone and 21% antibiotics. Five hundred and sixteen visits (49%) led to admission and 19% of those admitted required intravenous treatment. Probably some children who at present attend hospital for treatment of acute asthma could be managed at home, but this cannot be assumed without better understanding of the reasons for hospital attendance. More information is needed.

Acute Disease↗
PubMed1988

Pulmonary function in children after neonatal meconium aspiration syndrome.

Eighteen children aged 6 to 11 years old who fulfilled criteria for the diagnosis of neonatal meconium aspiration syndrome were investigated to find out the prevalence of previous and current respiratory symptoms, and abnormal pulmonary function tests, chest radiographs, and ventilation scans. Eleven of the 18 had no respiratory symptoms and eight of these had normal pulmonary function on testing. Two had mild limitation of expiratory airflow that did not respond to treatment with bronchodilators, and one had exercise induced bronchospasm that responded to treatment with bronchodilators. Seven of the 18 had recurrent cough and wheezing compatible with a diagnosis of asthma, and five of these had appreciable exercise induced bronchospasm that responded to treatment with bronchodilators. None of the children with symptoms had a personal or family history of atopy or had had acute bronchiolitis. All chest radiographs were normal. We found a much higher prevalence of asthmatic symptoms and abnormal bronchial reactivity among survivors of neonatal meconium aspiration syndrome than in the general childhood population. Aspiration of meconium may have long term consequences for the developing respiratory tract and is associated with abnormal respiratory function in later childhood.

Child, Preschool↗
PubMed1987

An unusual manifestation of staphylococcal lung infection.

An infant developed a rapidly progressive respiratory illness with cystic lesions on chest radiography. At thoracotomy there were multiple bullae on the surface of the lung. Staphylococcus aureus, of phage type 71, was isolated from the bullous fluid. We believe the lung disease was caused by an epidermolytic toxin.

Humans↗
PubMed1986

Gastrografin in acute meconium ileus equivalent.

Twenty-five (37%) patients with cystic fibrosis attending our clinic have experienced acute meconium ileus equivalent. In one year 37 of 40 episodes were treated with single dose oral Gastrografin with an 81% success rate, 75% being treated as outpatients. Patients found this treatment preferable to other recommended treatment.

Acute Disease↗
PubMed1983

Postural effects on gas exchange in infants.

In adults with unilateral lung disease, pulmonary gas exchange is better when the patients is positioned with the good lung dependent. We studied the effects of body position on gas exchange in 10 infants with unilateral lung disease by measuring transcutaneous oxygen and carbon dioxide pressures in the supine and right and left lateral positions. We also performed krypton lung scans and measured changes in thoracic gas volumes in four of the infants. Transcutaneous oxygen pressure (mean +/- S.E.) was greater with the good lung uppermost (82 +/- 7.6 mm Hg) than with the good lung dependent (73 +/- 7 mm Hg) (P less than 0.02) or in the supine position (78 +/- 7 mm Hg). There were no changes in transcutaneous carbon dioxide pressure. The proportion of ventilation to the good lung was greater with the good lung uppermost than with the good lung dependent (P less than 0.01) or in the supine position (P less than 0.02) (64 +/- 3, 46 +/- 6, and 59 +/- 7 per cent, respectively). There were no significant changes with position in functional residual capacity, tidal volume, or dynamic lung compliance. We conclude that oxygenation in infants with unilateral lung disease is best with the good lung uppermost--the reverse of what has been observed in adults.

Carbon Dioxide↗
PubMed1983

In vitro assessment of combined antibiotic and mucolytic treatment for Pseudomonas aeruginosa infection in cystic fibrosis.

The minimal inhibitory concentration of azlocillin for Pseudomonas aeruginosa is appreciably reduced when combined with the mucolytic agent mesna (Mistabron) because of an independent bacteriostatic effect of mesna. Bactericidal activity of azlocillin is unaltered by mesna. Mesna inhalations alone or combined with azlocillin may benefit cystic fibrosis patients with pseudomonas lung infections.

Azlocillin↗
PubMed1982

Changes in pulmonary function during the diuretic phase of respiratory distress syndrome.

To evaluate the relationship between improvement in pulmonary function and spontaneous diuresis in respiratory distress syndrome, nine premature infants requiring mechanical ventilation for RDS were studied at a mean age of 11.9 hours prior to the onset of diuresis, at onset of diuresis, at maximum urine output (mean age 44.9 hours), and at 24 hours after maximum urine output. Prior to diuresis functional residual capacity decreased from mean +/- SEM of 16.2 +/- 2 to 13.3 +/- 1.2 ml/kg, and dynamic lung compliance decreased from 2.5 +/- 0.3 to 1.8 +/- 0.3 ml/cm H2O (P less than 0.05), indicating that the respiratory disease was worsening. There was no significant change in alveolar-arterial oxygen gradient, peak inflating pressure, or rate of intermittent mandatory ventilation over this period. At the time of maximum urine output, however, FRC had increased 36% (P less than 0.05). CL had increased by 60% to 2.8 +/- 0.4 ml/cm H2O (P less than 0.025), AaDO2 had decreased from 246 +/- 27 to 184 +/- 30 torr (P less than 0.005), and PIP had decreased from 14.9 +/- 2.2 to 11.3 +/- 2.1 cm/H2O (P less than 0.05). On follow-up study 24 hours after maximum urine output, there was no further significant improvement in FRC, CL or PIP, but IMV rate and AaDO2 continued to decrease. These data show that the pulmonary function in RDS deteriorates until the onset of diuresis, after which it rapidly improves. This diuresis may represent the removal of excess lung liquid and seems necessary for improvement in RDS.

Diuresis↗
PubMed1982

Nasopharyngeal airways in Pierre Robin Syndrome.

Nasopharyngeal airways have been assessed in the management of infants with severe Pierre Robin syndrome. In 12 such infants the positioning and subsequent maintenance of these tubes were found to be important in ensuring adequate relief of the airway obstruction. In five infants measurements of lung mechanics demonstrated the benefits of NP tube placement and confirmed the observed improvements in cyanotic episodes, heart failure, electrocardiograms, and arterial gas tensions. In a retrospective survey of 40 infants with PRS, failure to thrive was found to be significantly correlated with the severity of the airflow obstruction. This failure to thrive was reversed in the infants managed with NP tubes in comparison with an age-matched groups nursed while prone. The lack of significant complications with the NP airway and its acceptability to nursing staff, patients, and their parents suggest that this method deserves more widespread use in PRS and perhaps in other situations in which high upper respiratory tract obstruction is predominant.

Airway Obstruction↗
PubMedDate not supplied

The accuracy of esophageal pressure measurements in convalescent and sick intubated infants.

Assessment of the esophageal pressure technique for measuring dynamic lung compliance (Cdyn) showed that accurate results were obtained in only 5 of 15 studies of sick intubated infants, whereas they were obtained in 6 of 6 studies of convalescent nonintubated infants. In sick infants, inaccuracy was due to large variations in esophageal pressure change (delta Pes) at different esophageal depths and difficulties validating Pes using the occlusion test. Methods of assessing lung stiffness that depend on the measurement of esophageal pressure are unreliable and should not be used in sick intubated infants.

Bronchopulmonary Dysplasia↗
PubMedDate not supplied

Comparison of the occlusion and inflation techniques for measuring total respiratory compliance in sick, intubated infants.

Respiratory system compliance (Crs) can be used to assess lung stiffness in sick, intubated infants, avoiding the use of an esophageal balloon. Crs was assessed in a group of 15 sick, intubated infants using the occlusion and inflation techniques. The occlusion technique gave satisfactory results in 13 infants. Apneic pauses following occlusion were obtained in infants up to 10 months of age. Satisfactory measurements of Crs were obtained in all 15 infants using the inflation technique, but difficulty was experienced in obtaining data over the tidal volume range in three of them. A close agreement was found between the two methods of measuring Crs in the ten infants in whom a direct comparison was possible.

Lung Compliance↗