When Can Free-flow Oxygen Be Discontinued

Neonatal emergencies are frightening and challenging to almost all acute care providers. This issue will focus on the neonate and provide a succinct review of resuscitation issues pertinent to clinical practice and board preparation/review.

Authors

Audrey Bowen, MD, FAAP, Assistant Professor of Pediatrics, University of Central Florida, Attending Physician, Florida Hospital, Children’s Emergency Center, Orlando, FL

You are viewing: When Can Free-flow Oxygen Be Discontinued

Winslade Bowen, MD, FAAP, Attending Neonatologist, Florida Hospital Memorial Center, Daytona Beach FL.

Dr. Audrey Bowen and Dr. Winslade Bowen report no financial relationships relevant to this field of study.

Newborn Resuscitation

An infant delivered in the emergency department (ED) or an infant presenting from an out-of-hospital delivery needs rapid assessment and possible resuscitation. Maternal history, pregnancy history, presence of gestational hypertension or diabetes, presence or absence of prenatal care, maternal age, and history of medications or drug use during pregnancy are important. Birth events, such as a precipitous delivery, presence of a nuchal cord, and excessive blood loss, may provide important information to help anticipate the need for immediate resuscitation of the newborn (and possibly the mother) and to predict the outcome of the infant.

Gestational age may be approximated based on the last normal menstrual period (LNMP) of the mother or based on ultrasounds done earlier in the pregnancy. The Ballard score assesses gestational age based on neuromuscular maturity (posture, square window, arm recoil, popliteal angle, scarf sign, heel to ear) and physical maturity (skin, lanugo, plantar surface, breast, eyes, ears, and genitalia).

Once a newborn has successfully been delivered, it is vital to quickly assess the need for resuscitation. The majority of full-term newborns do not require resuscitation. A quick assessment of the following three main characteristics will usually identify the need for resuscitation:

1. Is the infant term?
2. Is the infant crying or breathing?
3. Does the infant have good muscle tone?

If all the above are true, the infant usually does not need resuscitation. The infant should be dried and placed on mother’s chest for warmth. If the answer is no to any of the above questions, the infant requires resuscitation.

The 2010 American Heart Association Guidelines for Neonatal Resuscitation

The “Golden Minute” or first 60 seconds is the time frame for initiation of required resuscitation.1

• Term infant, breathing or crying, good tone: Stay with mother
• Preterm, not breathing or crying, poor tone: Warm, clear airway, dry, stimulate
• Labored breathing, persistent cyanosis: Clear airway, SpO2 monitor, supplemental O2, PPV if no improvement
• Heart rate < 100, gasping or apnea: PPV, SpO2 monitor,
• Heart rate < 60: ventilation/oxygenation corrective steps, consider intubation, chest compressions, PPV
• Heart rate < 60 despite initial resuscitative measures: Epinephrine (0.01-0.03 mg/kg IV or 0.05-0.1 mg/kg via ETT) If heart rate still < 60 despite epinephrine administration: Consider hypovolemia (give normal saline bolus 10 mL/kg), hypoglycemia (check blood sugar), and pneumothorax (needle decompression for tension pneumothorax)

National Guideline/Academic Resource

The 2010 Neonatal Resuscitation Guidelines are available at: Guidelines

Supplemental Oxygen, Intubation, and Compressions

Assisted Ventilation and Supplemental Oxygenation. Infants in the normal transition from intrauterine to extrauterine life may take a few minutes to increase the oxygen saturation SpO2 from about 60% (normal intrauterine state) to > 90%. The values may be slightly lower after cesarean sections compared with vaginal deliveries. The pulse oximetry probe should be placed on the right arm, which receives blood before it reaches the ductus arteriosus (pre-ductal). The ductus may remain open for hours after birth, so the blood in the aorta distal to the ductus may mix with blood with low oxygen levels from the pulmonary artery via the ductus arteriosus. Oxygen may be supplied to the infant to achieve the targeted saturation values.2 (See Table 1.)

Table 1. Targeted preductal SpO2 after birth

Read more : When Replacing A Fuse You Must Match The

1 minute 60-65% 2 minutes 65-70% 3 minutes 70-75% 4 minutes 75-80% 5 minutes 80-85% 10 minutes 85-95%

The standard practice of administering 100% oxygen to all neonates needing supplemental oxygen is no longer recommended. Recent studies have shown that resuscitation with room air likely improves outcomes. National guidelines now recommend initiating resuscitation with blended oxygen; if an oxygen blender is unavailable, resuscitation should be initiated with room air. In either case, the oxygen concentration should be titrated to achieve the targeted preductal saturation. If the heart rate remains < 60 bpm after 90 seconds of resuscitation, the oxygen concentration should be increased to 100% until the heart rate improves.

Free-flow (“blow-by”) oxygen can be given to an infant breathing spontaneously by several methods: an oxygen mask, a flow inflating bag and mask, a T-piece resuscitator, or oxygen tubing held close to the infant’s mouth and nose. The mask should not be held tightly against the face, as this may cause excess pressure to build up inside the mask. It is important to have the right size mask, which should rest on the chin and cover the mouth and the nosebut not the eyes.

Oxygen supplementation is adjusted and should be gradually decreased as the pulse oximetry levels improve to > 85-90% on room air. If there is persistent cyanosis with oxygen saturations < 85% despite oxygen administration, a trial of PPV is indicated. Effective ventilations should produce bilateral breath sounds and chest wall movement. PPV may be discontinued if the heart rate rises > 100 bpm, if there is improvement in oxygen saturation, and if there is onset of spontaneous respirations. If cyanosis persists despite adequate ventilation, the presence of a cyanotic congenital heart defect or persistent pulmonary hypertension may exist. If PPV is continued for more than several minutes, an orogastric tube (size 8F feeding tube) may be helpful to avoid abdominal distention, which places upward pressure on the lungs preventing full lung expansion and may cause regurgitation and aspiration of stomach contents.

National Guideline/Academic Resource

http://pediatrics.aappublications.org/content/early/2010/10/18/peds.2010-2972E.full.pdf

Chest Compressions. Chest compressions are indicated when the heart rate is < 60 bpm despite stimulation and at least 30 seconds of PPV.3 Compressions are performed to the lower third of the sternum, and the pressure is applied vertically using one of two different techniques:

• Thumb technique: Two thumbs are used to compress the sternum and the hands encircle the torso with the fingers supporting the spine. This method is preferred because it is easier to control the depth of compressions and provide more consistent pressure.
• Two-finger technique: Two fingers (middle finger and index or ring finger) of one hand are used to depress the sternum. The other hand is used to support the infant’s back.

The sternum should be depressed to a depth of approximately one-third of the anterior-posterior diameter of the chest. There should be complete chest recoil during the relaxation phase of the chest compression. The chest compressions and ventilation should be coordinated: one ventilation for every third compressionand a total of 30 breaths and 90 compressions every minute. After 45-60 seconds of chest compressions and ventilations, the heart rate should be checked. When the heart rate is > 60 bpm, chest compressions may be stopped and ventilations may be increased to a rate of 40-60 breaths per minute. If spontaneous respirations occur and the heart rate is > 100 bpm, PPV may be stopped. If the heart rate is < 60 bpm, endotracheal intubation should be performed, and epinephrine (0.01-0.03 mg/kg) should be administered via the intravenous route. If IV access has not yet been established, epinephrine may be administered via the endotracheal route (0.5-0.1 mg/kg via ETT) while an IV is inserted.

Intubation.The indications for intubation3 in the immediate newborn period include:

• The presence of meconium in an infant who has depressed respiratory effort, muscle tone, or heart rate. The trachea is intubated as the first step to allow suctioning of the meconium and thus decreasing the possibility of meconium aspiration syndrome.
• When PPV has not resulted in clinical improvement, and there is poor chest movement.
• When there is prolonged need for PPV, intubation will improve ventilation efforts.
• When chest compressions are necessary, intubation facilitates the coordination of compressions and ventilation.
• For special resuscitation scenarios such as congenital diaphragmatic hernia.

PPV is not the ventilation method of choice in situations such as extreme prematurity, need for surfactant administration, or presence of a congenital diaphragmatic hernia. Intubation and mechanical ventilation is the preferred method in these newborns.

National Guideline/Academic Resource

http://pediatrics.aappublications.org/content/early/2010/10/18/peds.2010-2972E.full.pdf

APGAR Score

A newborn is assigned an APGAR score at birth based on heart rate, respiratory effort, muscle tone, reflex irritability, and color.4 The values are added to determine the APGAR score at 1 minute and 5 minutes. Newborns with a score of 7-10 generally need no further intervention or resuscitation. If the score at 5 minutes is ≤ 7, the infant should be assigned a score every 5 minutes up to 20 minutes. (See Table 2.)

Read more : When Is Finn Wolfhard’s Birthday

Table 2: APGAR Scores

Score 0 1 2 Heart rate Absent < 100 bpm > 100 bpm Respiratory effort Absent/Irregular Weak cry Strong cry Muscle tone Limp Some flexion Active Reflex irritability/p> No response Grimace Cry/active withdrawal Color Blue or pale Acrocyanosis Pink

Induced Hypothermia

Several randomized, controlled, multicenter trials of induced hypothermia (33.5°-34.5° C) of newborns > 36 weeks gestational age, with moderate-to-severe hypoxic-ischemic encephalopathy, demonstrated that babies who were cooled had significantly lower mortality and less neurodevelopmental disability at 18-month follow-up than babies who were not cooled.

References

1. Kattwinkel J, Perlman JM, Aziz K, et al. Neonatal Resuscitation: 2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular and Emergency Cardiovascular Care. Pediatrics 2010;126:e1400-1413.

2. Cloherty JP. Manual of Neonatal Care. 7th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2012.

3. Dawson JA, Kamlin CO, Vento M, et al. Defining the reference range for oxygen saturation for infants after birth. Pediatrics 2010;125:e1340-1347.

4. Apgar V. A proposal for a new method of evaluation of the newborn infant. Curr Res Anesth Analg 1953;32:260-267.

5. Polin RA, Carlo WA; Committee on Fetus and Newborn; American Academy of Pediatrics. Surfactant replacement therapy for preterm and term neonates with respiratory distress. Pediatrics 2014; 133:156-163.

6. Kattwinkel J. ed. Textbook of Neonatal Resuscitation. 6th ed. Elk Grove Village. IL: American Academy of Pediatrics; 2011.

7. Hedrick HL, Crombleholme TM, Flake AW, et al. Right congenital diaphragmatic hernia: Prenatal assessment and outcome. J Pediatric Surg 2004;39:319-323.

8. Campbell BT, Herbst KW, Briden KE, et al. Inhaled nitric oxide use in neonates with congenital diaphragmatic hernia. Pediatrics 2014;134:e420-e426.

10. Stark AR, American Academy of Pediatrics Committee on Fetus and Newborn. Levels of neonatal care. Pediatrics 2004;114:1341-1347.

Neonatal resuscitation

Source: https://t-tees.com
Category: WHEN