TWO PATIENTS IN ONE
Baby S at 3 weeks of age and 930g Images reprinted with permission
Baby S born at 25 weeks gestation and 760g more likely to be “ smaller ( for their gestational age ) and sicker ( than they used to be ),” effectively freezing the morbidity / mortality curve for premature infants over the past quarter century .
The decision to resuscitate and provide initial NICU care to premature infants at the border of viability continues to remain both difficult and controversial . The use of large databases , specifically the National Institute of Child Health and Human Development ( NICHD ) Extremely Preterm Birth Outcomes Tool , has helped to more accurately quantify the likelihood of not just survival , but the long-term morbidities that accompany those survivors . 7 Many neonatologists have begun to move away from a limited approach based solely on gestational age , in favor of a risk-based approach . This considers several known favorable co-factors : female sex , singleton pregnancy and antenatal steroids along with the detrimental effect of intrauterine growth restriction . At one time it was just as inconceivable to offer resuscitation at 22 weeks , as it was to not offer care at 25 weeks . But database risk analysis has shown that an imminent 22-week delivery with an entirely positive risk profile is comparable to a 25-week delivery with an entirely negative profile . To make the issue even more complex , the ever changing , state-bystate legislation intended to put a corral on abortion has had the ( perhaps unintended ) consequence of making the decision whether to offer resuscitation , even with nearly futile cases , a potential legal minefield . 8
In response , the decision has steadily moved to a family-centered approach with prenatal consultation and a clearer understanding of informed consent when initiating care that sometimes is more likely than not to have a poor outcome . Unfortunately , many emergency situations arise in which decisions must be made in the moment . Nevertheless , we potentially face liability for both “ failure to resuscitate ” what would have been an extremely unlikely intact survival , as well as its converse , an “ unintended life ” with neurodevelopmental impairment and cerebral palsy .
For most premature infants , there tend to be three distinct phases of care after admission to the NICU : the “ acute ” phase that may last months for a 24-week infant but only days for a 34-week infant , the “ feeding and growing ” phase which continues until 34 to 36 weeks corrected age , and finally the “ discharge planning ” phase .
Baby S at 30 months of age
During the initial “ acute ” phase of care , most premature infants experience some degree of Respiratory Distress Syndrome ( RDS ) due to a varying amount of surfactant deficiency , which can be magnified and prolonged in the face of incomplete development of the pulmonary architecture in the most premature infants . At its essence , RDS is essentially a disease of atelectasis , and its hallmark sign of “ grunting ” is the result of an infant attempting to prevent alveolar collapse using a prolonged expiratory phase to maintain internal end expiratory pressure . In kind , the cornerstone of treatment of RDS is to provide continuous positive airway pressure ( CPAP ) and when indicated , intratracheal surfactant . The earlier the gestation , the more likely the infant will require the double-edged sword of positive pressure ventilation , which assures life sustaining gas exchange , but at the expense of potential pulmonary damage . It can increase the likelihood the infant will develop chronic lung disease in the form of bronchopulmonary dysplasia ( BPD ). At the earliest gestations , such damage can lead to air-leak syndromes , such as pneumothorax , pneumomediastinum and pulmonary interstitial emphysema ( PIE ) which may require unconventional ventilation strategies , specifically high-frequency ventilators capable of delivering more than 600 breaths per minutes at tidal volumes less than physiologic dead space . 9 For the treatment of prolonged RDS and BPD , there is no shortage of both invasive and non-invasive ventilation strategies , with a typical NICU offering more than ten distinct modalities with countless variations when smart , computer-based ventilators are included .
For many neonatologists , it takes many years to understand that for the sickest infants , the main goal during the acute phase is stabilization , more than extubation . A stable infant , who manages to avoid large swings in oxygenation , respiratory or metabolic acidosis
( continued on page 10 ) MARCH 2022 9