Neonatal Intensive Care Nurse Test Review
1. A 29-week neonate presents with the following arterial blood gas values:
pH - 7.36
pCO2 - 52
HCO3 - 30
These values would indicate which of the following?
A. Compensated metabolic acidosis
B. Compensated respiratory acidosis
C. Uncompensated respiratory acidosis
2. With regard to oxygen delivery, which of the following scenarios would be an appropriate indication for using a nasal cannula in an infant?
A. A 32-week old, gavage-fed infant who requires 2 lpm O2 to maintain a SpO2 greater than 90%
B. A 33-week old infant who requires FiO2 of 0.5 (50%) to maintain SpO2 greater than 90%
C. A 34-week old infant who is bottle-feeding and requires 0.5 lpm O2 to maintain a SpO2 greater than 90%
3. Which of the following patient scenarios is NOT a candidate for mechanical ventilation?
A. 27-week infant weighing 980 g, respiratory rate 80/min, mild retractions
B. 34-week infant weighing 2400 g, respiratory rate 42/min, in oxyhood at FiO2 30%
C. 38-week infant weighing 3200 g, respiratory rate 60/min, grunting, marked retractions, in oxyhood at FiO2 45%, SpO2 falling
4. Which of the following infants are at the highest risk for insensible water loss?
a. 28-week-old infant in an open-bed warmer
b. 30-week-old infant in closed Isolette incubator
c. Term infant, born on way to hospital
d. 36-week-old infant in open bassinet with respiratory rate 64/min
A. a, b, c
B. b, c, d
C. a, c, d
5. What conditions exist in tetralogy of Fallot?
a. Left ventricular hypertrophy
b. Pulmonary stenosis
c. Atrial septal defectbr
d. Overriding aorta
A. a, c
B. a, c, d
C. b, d
Answers & Explanation
1. B: In this scenario, although the pH is WNL (within normal limits), this does not mean this is a normal blood gas. All measurements must be taken into consideration for proper interpretation. Acidosis or alkalosis has one of three causes: respiratory, metabolic, or mixed. Usually, in an otherwise healthy premature neonate, the cause of an abnormal blood gas due to underdeveloped lungs which leads to a buildup of CO2 in the bloodstream. The indicator for a respiratory imbalance is pCO2. High pCO2 usually indicates a case of respiratory acidosis. When coupled with a high level of HCO3 (bicarbonate-which is base), it is an indication of the body trying to compensate for the high CO2 in the bloodstream. Whether an imbalance is compensated or uncompensated is determined solely by the pH. If the pH is within normal range, the state is compensated.
2. C: Nasal cannulas are appropriate for infants that require less than 1 lpm (liter per minute) O2. Cannulas will also allow for uninterrupted bottle feeding. Infant nasal cannulas will only provide an O2 flow of less than 1 lpm. Infants that require higher flow rates or concentrations of FiO2 greater than 0.4 (40%) will require alternate delivery methods.
3. B: Many factors contribute to the need for mechanical ventilation in a neonate. One must take into consideration all aspects of respiratory function to determine if mechanical ventilation is necessary. General guidelines include signs of impending respiratory failure (respiratory rate greater than 60/min, retractions, grunting, nasal flaring), apnea, and presence of existing respiratory failure. Other factors may also be indications for mechanical ventilation, including certain congenital anomalies that may interfere with respiration, septic infants, and infants weighing less than 1000 g.
4. C: Insensible water loss is defined as evaporative water loss through the skin and respiratory tract. Open-air warmers and bassinets can pose a risk for increased insensible water loss through the skin via exposure to environmental air currents. This is especially true with open warmers, as infants are either nude or just wearing a diaper, thus exposing a majority of skin to the surrounding air. This is why it's important to position warmers and bassinets out of drafts. Tachypnea (respiratory rate greater than 60/min) increases insensible water loss through rapid respiration. Babies born in uncontrolled environments are subject to greater insensible water loss due to improper drying and swaddling in the field.
5. C: Tetralogy of Fallot (ToF) is a congenital cardiac defect that occurs in approximately 1:2000 live births. It is characterized by the presence of four structural defects within and surrounding the heart. The four components are right ventricular hypertrophy, pulmonary stenosis, ventricular septal defect, and overriding aorta. ToF is the major cause of the so-called "blue baby syndrome."
Last Updated: 04/18/2018