Walsh: Perinatal and Pediatric Respiratory Care, 3rd Edition

Chapter 29: Neonatal Complications of Respiratory Care

Answers to Assessment Questions and Clinical Scenarios

1.	D
Rationale: Most clinicians now define chronic lung disease (CLD) as occurring in an infant who required oxygen or mechanical ventilation, and still continues to require oxygen at 36 weeks of gestational age.
2.	E
Rationale: Ironically, while ventilation and oxygen use probably are two factors involved in producing CLD, without these two therapeutic modalities few infants would survive at all. Another factor is surfactant dysfunction.
3.	D
Rationale: Meta-analyses have shown that infants resuscitated at birth with room air have less oxidative stress, a more rapid establishment of normal breathing, and a reduction in reperfusion damage to major organs (brain, heart, and kidneys).
Increasing antioxidants intake could offset newborn oxidative stress. Unfortunately no intravenous or dietary compounds have been proven safe for prolonged use. Even with much-studied vitamin E (-tocopherol), plasma measurements are unreliable, and prolonged dosage with vitamin E has been involved with an increased incidence of sepsis and necrotizing enterocolitis (NEC).
4.	D
Rationale: Oxidative stress and mechanical ventilation both lead to inflammation, and the neutrophil is the most prevalent cell in the alveolar washings of infants with RDS. With resolution of RDS or mild lung disease, the neutrophil numbers decrease. If the infant develops CLD, however, the neutrophil numbers persist.
5.	E
Rationale: Surfactant replacement may be used to reduce mortality and morbidity associated with RDS leading to chronic lung disease; CPAP avoiding ET intubation may be used to reduce mortality and morbidity associated with RDS leading to chronic lung disease; iNO may be used to reduce mortality and morbidity associated with RDS leading to chronic lung disease.
6.	E
Rationale: ROP is diagnosed and staged by the description of retinal fibrovascular changes as outlined by the International Committee for the Classification of ROP criteria. Disease changes are described by location (e.g., zone I, II, or III), extent (number of clock hours involved), and severity.
7.	D
Rationale: There is no treatment that halts or reverses the effects of ROP. All other therapies, laser ablation, vitamin E, oxygen supplementation, and light reduction, proven or unproven, are directed toward halting, minimizing, or preventing damage.
8.	C
Rationale: If autoregulation is absent, any factor adversely affecting systemic blood pressure puts the brain at risk of ischemia or hemorrhage because of the pressure-passive status of cerebral blood flow.
Some factors reported to alter cerebral blood flow (CBF) and put the infant at risk of intraventricular hemorrhage (IVH)/periventricular leukomalacia (PVL) are as follows: hypotension, hypoplastic left heart syndrome, patent ductus arteriosus (PDA) (with retrograde cerebral diastolic flow), thrombocytopenia, pneumothorax, hypoxemia, hypercarbia, hypocarbia bicarbonate infusions, umbilical arterial catheter (UAC) blood withdrawal, ET suctioning, and mechanical ventilation.
9.	D
Rationale: IVH is frequently diagnosed in the neonatal intensive care unit (NICU) by cranial ultrasound examination (HUS). Magnetic resonance imaging (MRI) may be performed but the infant would have to leave the NICU and be subjected to cold stress. After IVH occurs, the lesion is described as involving the right or left hemisphere and graded according to a standard system.
10.	B
Rationale: CF may be a consideration, but the most likely diagnosis based on the course of these X-rays is BPD, or some form of chronic lung disease related to prematurity (see Table 29-1).