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The nasal continuous positive airway pressure (NCPAP) ElectroMedical Equipment (EME) system has recently gained wide use in premature infants. However, occasional impingement of the expiratory tubing exit by mattress, coverings, or walls of infant warmers is of concern because of risk for obstruction and pneumothorax. The purpose of this study was to verify whether the use of NCPAP, namely Aladdin-1 (EME, Brighton, England), increases the risk for pneumothorax. The study included premature infants with respiratory distress who necessitated one or more of the following modes: oxygen via head box, NCPAP, synchronized intermittent mandatory ventilation (SIMV), or high frequency oscillatory ventilation (HFOV). For every patient, we recorded the modes of respiratory support, duration of use, and the occurrence of pneumothorax during every mode (number of pneumothorax cases/100 days of support). Among 163 sick premature neonates, pneumothorax developed in 0.17, 1.77, 0.3, and 6 cases per 100 days of oxygen via head box, NCPAP, SIMV, and HFOV, respectively. Pneumothorax developed more often during NCPAP than with SIMV. Pneumothorax in premature infants might be increased with the use of the newly developed NCPAP system. In these circumstances, possible accidental obstruction of the exit of its expiratory tubing could be contributory to this complication.

The feasibility of intratracheal pulmonary ventilation (ITPV) was tested in five ventilated moribund neonatal and pediatric patients with uncontrollable hypercapnia: a 2-year-old child, a 52-day-old infant, and three premature infants (29, 29, and 26 weeks gestation; 1300 g, 1100 g and 890 g birth weight, respectively). ITPV was applied for 9.5, 8, 25, 58.5, and 47.5 hr, respectively. An intratracheal catheter (Cook Critical Care, Inc., Bloomington, IN) with a reversed continuous flow of gas at its tip (away from the lungs) allowed flushing of CO 2 from the proximal dead space. Marked reductions in Pa CO2 , ranging from 37% to 71% and improvement in pH were achieved within 4-6 hr of applying ITPV. During ITPV, the mean lowest Pa CO2 was significantly less than the pre-ITPV Pa CO2 (p < 0.0017), and the mean best pH was significantly higher than the pre-ITPV pH (p < 0.015). In four patients, despite significant reductions in Pa CO2 , there was no substantial improvement in their baseline condition (shock and severe metabolic acidosis or coma) and they were switched back to conventional ventilation. This led to worsening hypercapnia to pre-ITPV values. These four patients subsequently died. It is possible that these patients were already too ill to derive significant benefit from the technique. One premature infant survived, was successfully weaned to conventional ventilation and was eventually discharged home. ITPV can alleviate uncontrollable hypercapnia in ventilated neonatal and pediatric patients.

The ultra thin walled, two-stage endotracheal tube (UTW-TS-ETT) is very flexible, nonkinking, and has a widened extralaryngeal portion. The UTW-TS-ETT has a greater ID/OD (internal diameter/outer diameter) ratio than a comparable standard endotracheal tube (ST-ETT) because of its thinner wall: 0.2-0.25 mm in UTW-TS-ETT, compared to 0.55-0.8 mm in ST-ETT. The authors hypothesized that in an animal model of lung disease, significant reductions in respiratory system resistance (Rrs) of 30-40% would be achieved using the UTW-TS-ETT, compared to Rrs achieved with the comparable ST-ETT. This study compared the pulmonary mechanics of rabbits (N = 17, body weight 3.4-4.7 kg) before and after induction of surfactant deficiency, using either ST-ETT (OD 4.9 mm, ID 3.5 mm) or UTW-TS-ETT (OD 5.0 mm, ID 4.6 mm). Animals were sedated, paralyzed, and ventilated by an ETT placed through a tracheotomy incision. Surfactant deficiency was induced by lavaging the lungs with normal saline (10 ml/kg). Pulmonary mechanics were measured on identical ventilator settings for each ETT used at baseline and at 45 min after lavage. Compared to ST-ETT, UTW-TS-ETT reduced Rrs by 50.6 +/- 8.7% in normal lungs (significantly more than 40%; p < 0.01), and by 41.47 +/- 16.2% in surfactant deficient lungs (significantly more than 30%; p < 0.05). Tidal volume increased with UTW-TS-ETT in all animals but did not achieve statistical significance. The UTW-TS-ETT did not induce significant changes in respiratory system compliance, PaO2, PaCO2, or pH. It is concluded that UTW-TS-ETT significantly reduces Rrs in rabbits with either normal lungs or with surfactant deficient lungs. This novel ETT may be beneficial for ventilated patients with increased Rrs, by effecting a decrease in Rrs and thus reducing the work of breathing and improving ventilation efficiency.

Despite the introduction of new ventilation techniques and surfactant therapy, some premature infants still experience severe respiratory failure and either die or survive with severe bronchopulmonary dysplasia. Extracorporeal membrane oxygenation is currently not offered for preterm infants with a birth weight less than 2,000 g, mainly because of the potential high risk for intracranial hemorrhage. The aim of this study was to determine risk predictors for mortality alone and for mortality or major lung morbidity in 1,500-1,999 g premature infants with respiratory failure. We reviewed the medical records of all preterm infants (n = 459) with respiratory failure and a birth weight of 1,500-1,999 g treated at five medical centers from 1989 to 1991. Of those infants, 23 (5%) had severe respiratory failure, defined as a requirement for ventilatory support with the fraction of inspired oxygenor = 0.8 or peak inspiratory pressureor = 30 cmH2O foror = 3 hr in the 1st week of life. A mortality ofor = 75% was associated with a single arterial/alveolar oxygen ratioor = 0.04; pulmonary air leak alone or pulmonary air leak with a mean airway pressureor = 12 cmH2O; and arterial oxygen tensionor = 50 mmHg. These risk predictors may provide a basis for the selection of patients for future clinical trials of extracorporeal membrane oxygenation in this high-risk group of 1,500-1,999 g premature infants with severe respiratory failure.