Mechanical ventilation in the respiratory distress syndrome: a controlled trial

A controlled study of mechanical ventilation has been performed in infants with respiratory distress syndrome. 168 infants in respiratory failure were ventilated and 53 similar infants were not. Artificial mechanical ventilation improved survival in infants weighing more than 2000 g. from 15% to 43% (4/27 vs. 29/67, p < 0·025). Infants who weighed more than 1500 g. and developed respiratory failure at less than 38 hours of age had an improved survival (16/31) on ventilatory treatment, as compared with infants more than 1500 g. ventilated at more than 38 hours of age (24/78) (p < 0·05). Artificial ventilation improved P_ao₂, P_aco₂, and [H⁺]_a within one hour, but it was only the change in [H⁺]_a in infants more than 2000 g. which was of prognostic significance. Survival rates were similar for each of the three types of respirator used.

A controlled trial of assisted ventilation using an oro-nasal mask

A controlled study was performed to assess the effect of early assisted ventilation using a tight fitting face mask. Early mask ventilation reduced the number of infants requiring intubation, but did not significantly alter the survival rate. Complications were seen in infants during both mask ventilation and ventilation with a naso-tracheal tube. Persistent radiological changes were seen in 5 of 9 infants who survived after ventilation for more than 5 days..

Ventilator therapy in the newborn. Some mechanical considerations

Premature infants have been studied while receiving intermittent positive pressure ventilation for the management of respiratory failure which was due either to severe respiratory distress syndrome or to apnoea of prematurity. Simultaneous recordings were made of transpulmonary pressure change and volume change induced by a pressure-regulated intermittent positive pressure ventilator. This information has been of clinical value in selecting a ventilator setting for individual infants. Using an electrically-switched pressure-limited ventilator the following settings have been found to be the most appropriate in the various forms of neonatal respiratory failure: rate, 50-70/min., pressure blow-off, 20-35 cm. H₂O; inspiratory duration, 30-35% of the respiratory cycle; flow of gas in the circuit, 5-7 1./min.

Clinical evaluation of a new silastic tracheostomy tube for respiratory support of infants and young children

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Management of the respiratory distress syndrome

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Negative pressure artificial respiration: use in treatment of respiratory distress syndrome of the newborn

Forty-five newborn infants in respiratory failure with respiratory distress syndrome were treated with intermittent negative pressure ventilation (INPV). There was a survival rate of 38% (17/45).All infants were initially treated without nasotracheal intubation. However, 24 of these developed a Paco(2) greater than 70 mm. Hg and were subsequently intubated. Intubation was followed by a decrease in the degree of hypercarbia in each instance and simultaneous increase in Pao(2).COMPLICATIONS ENCOUNTERED DURING VENTILATION WERE: emphysema (one patient), aspiration pneumonia (two patients), septicemia (two patients), misplaced nasotracheal tube (one patient).Follow-up of the 17 surviving patients for periods of four to 36 months disclosed two patients with post-intubation hoarseness. One infant initially had spastic quadriplegia with EEG abnormalities, both of which cleared by 5 months of age. In the remaining 14 infants, the results of physical, neurological and psychological examinations have remained within normal limits.

Negative pressure artificial respiration: use in treatment of respiratory failure of the newborn

Ninety-one infants with respiratory failure secondary to primary pulmonary disease and with a birth weight of 1000 g. or over have been managed in a negative-pressure respirator (Air-Shields) over a three-year period. Of these the failure in 87 was due to respiratory distress syndrome (RDS) and in four it resulted from massive meconium aspiration. Respiratory failure was indicated initially by arterial blood gas tensions (while breathing 100% O(2)) of Po(2) <40 mm. Hg, pH <7.10 and Pco(2) >75 mm. Hg in the initial 47 cases; these levels were subsequently raised to Po(2) < 50 mm. Hg, pH <7.20 and Pco(2) >70 mm. Hg for the remainder. Fifty-four (59.3%) of the infants survived the use of the respirator and 47 of these (51.6%) were subsequently discharged alive and well. Mean time in hours to normalization of blood gas values while on the respirator were as follows: for Po(2), 10.5; for pH, 11.6; and for Pco(2), 22.6. These values indicate that the respirator is more efficient in promoting oxygenation (raising Po(2)) than ventilation (lowering Pco(2)). They also suggest that the observed acidosis is in large part secondary to the hypoxia rather than the result of co(2) retention. For the survivors the average time of total respirator dependency before commencement of weaning was 53.7 hours. All the infants were managed without the use of endotracheal tubes although the use of the respirator and/or administration of 100% oxygen were either continuous or intermittent for periods of up to two weeks. There have been no instances of so-called respirator lung disease in the survivors or in those who died, which suggests that the use of high oxygen concentration by itself is not the major factor in the pathogenesis of this complication.