Biomedical subjects

N J Freezer

Publications and source records attributed to N J Freezer.

3 recordsLinked to original sources

PubMed1991

Pulmonary mechanics and outcome of neonates on ECMO.

Deciding when to wean neonates from extracorporal membrane oxygenation (ECMO) can be difficult. The usefulness of simple measurements of pulmonary mechanics e.g., dynamic compliance (Cdyn) has been questioned. We investigated the pulmonary mechanics of eight neonates using the interrupter technique, which allows the partitioning of pulmonary mechanics into compartments representing the conducting airways and more peripheral phenomena (viscoelastic properties and "pendelluft"). Three neonates required ECMO for a congenital diaphragmatic hernia (CDH), two for hyaline membrane disease (HMO), two for meconium aspiration syndrome (MAS), and one for pneumonia. All neonates with MAS, HMD, and pneumonia were successfully weaned from ECMO when their Cdyn was 0.3 mL/cmH2O/kg or greater [mean 0.34 +/- 0.06 (SEM)]. All three neonates with CDH died and their highest Cdyn was 0.21, 0.19, and 0.09 mL/cmH2O/kg respectively (mean, 0.16 +/- 0.037). The airway resistance (Raw) and the slower component of pressure change after interruption (delta Pdiff), a measure of the more peripheral phenomena of the lung, were not significantly different in those neonates who survived and those who did not. The values for delta Pdiff in all patients were higher than those in healthy neonates. However, the Raw was not different. This suggests that the major disturbance in pulmonary mechanics was distal to the conducting airways. Those neonates who were successfully weaned from ECMO had a significantly higher Cdyn 24-48 hours prior to decannulation. Considering the lung as a two-compartment model offers no advantages when compared to the one-compartment model for the prediction of the outcome of a neonate on ECMO.

Airway Resistance↗

PubMed1990

Tracheostomy in children with Guillain Barré syndrome.

During the 10-yr period beginning January 1979, 59 infants and children with Guillain Barré syndrome (GBS) were admitted to our hospital. Tracheostomies were performed in 15 patients and their records were reviewed. Fourteen patients were recalled for assessment of pulmonary function and respiratory muscle strength (RMS). The median duration of assisted ventilation (including endotracheal [ET] intubation) was 21 days and the median duration of tracheostomy was 39 days. Only two patients were discharged with the tracheostomy in situ. All patients were successfully decannulated at the first attempt. No tracheostomy-related complications or symptoms were reported apart from croup in two patients. On review, lung volumes and maximal inspiratory and expiratory flows were normal. There was no evidence of tracheal stenosis or significant tracheomalacia. RMS tests were normal. In this hospital, tracheostomy is a safe, well-tolerated procedure in the management of infants and children with GBS who need long-term ventilation. There were no deaths and all patients returned to their normal school or were gainfully employed after their illness, although 12 patients had mild persistent weakness of at least foot dorsiflexion.

Adolescent↗

PubMed1990

Tracheostomy.

The records of all children who had a tracheostomy performed over a 10 year period from January 1979 were reviewed. Altogether 142 patients aged 1 day to 24.8 years received a tracheostomy, 70 in the first year of life. The conditions necessitating tracheostomy were trauma (n = 21), acquired subglottic stenosis (n = 21), subglottic haemangioma (n = 16), Guillain-Barré syndrome (n = 14), Pierre Robin syndrome (n = 9), craniofacial disorders (n = 9), micrognathia (n = 5), and others in 47. In patients successfully decannulated the median period of tracheostomy was 104 days (range 3 days to 9.0 years) and in 25 patients the tracheostomy is still in situ. Eighty four patients (60%) were discharged from hospital with their tracheostomy in situ and no patient was kept in hospital because of a tracheostomy beyond four weeks. There were two tracheostomy related deaths in hospital. Both patients had severe acquired subglottic stenosis secondary to ventilation for lung disease of prematurity. There were no tracheostomy related deaths at home; complications included tracheal granulomas and polyps (n = 19). After removal of the tracheostomy 13 children had a fistula requiring surgical closure and four required revision of the tracheostomy scar. Tracheostomy is well tolerated in small children, with few complications and can be managed safely in the home by the family.

Adolescent↗