Everything You Need to Know About the Infant Resuscitator
An infant resuscitator is one of the essential equipment used by pediatricians mostly in the context of respiratory distress or cardiopulmonary resuscitation of a newly born child. The apparatus aims to deliver optimum oxygenation to tissues via safe inflation and adequate ventilation of the baby's lungs. Within the first few seconds of life, the lungs are collapsed and filled with fluid. The earliest breath taken by a newborn child is the most profound and difficult step to change, driven by the mother's womb's transition to the external world. This step is essential to inflate the lungs and begin the spontaneous process of respiration—the inhalation of oxygen and the exhalation of carbon dioxide.
Though most babies undergo the vital process naturally after the delivery, some of them do not. 10% of newborns fail to establish effective, spontaneous respiration, and they need medical assistance and pulmonary resuscitation. Pulmonary reanimation aims to clear the airway and prevent hypoxia through the vital practice of delivering and maintaining a controlled PIP (positive air pressure) and a PEEP (positive end-expiratory pressure) to establish adequate ventilation.
The use of infant rusticators significantly reduced mortality caused by birth asphyxia. The latter results in damage to the vital organs, particularly the brain, and is one of the leading causes of death among neonates. In this article, we will cover the history of infant resuscitators, their intended use, standard specifications, and some variables that offer the same value.
History of infant resuscitators
From the first experiments with oxygen, it became evident that it is a vital element for life, and its inhalation brings revival to asphyxiated individuals. Its use as medical reanimation aid started in around 1895 when oxygen was successfully produced and made available in a handy, compressed form.
Delivering free-flow oxygen to a patient in a critical condition requires ventilation, positive pressure, and effort to establish adequate respiration.
In 1907, Germany, Draeger of Lubeck solved that issue and introduced the first pulmotor resuscitator, an automatic pressure-cycled apparatus that delivered a cycle of a breathing pattern—creating positive pressure on inhalation and negative pressure on exhalation.
Later on, the device's sensitivity was questioned as it caused many complications, especially among children and infants whose airways are fragile and vulnerable to dynamic pressure change. In addition, it caused more harm than good in patients with chronic obstructive pulmonary disease. Also, the device could not be used in cardiopulmonary resuscitation (cardiac arrest), because applying cycled pressure simultaneously with chest compressions is impossible. These issues condemned the device by the medical profession.
The revolutionary invention of the Demand valve in 1942 offered a valuable addition to resuscitators. It provided rapid high flow oxygen delivery to the lungs, which was more regulated than the cycling process. The valve thus allowed for better coordination between chest compressions and the inflation of the lungs.
Further advancements of resuscitators involved the addition of Ayre's T-piece, a piece of vital equipment initially designed for endotracheal anesthesia for pediatric use.
New technologies improved infant resuscitators' performance to make it safe and harmless to the newborn lungs, with better control over the pressure delivered through PIP and PEEP, avoiding the potential risk of lung injury during resuscitation.
Indications to use infant resuscitators
Neonatal asphyxia is the main indication for the infant resuscitator. An infant also needs resuscitation in the following cases: respiratory failure, bradycardia (heart rate less than 100 beats/min), and central cyanosis that persists despite the administration of free-flow oxygen.
Neonatal asphyxia is also known as birth or perinatal asphyxia. The neonatal period is the phase of life with the highest risk of mortality. The condition can be anticipated only in half of the cases. The rest of it comes in a complete surprise. So, resuscitation equipment needs to be always available, especially when the baby is born before term (delivering at 37 weeks or 38 weeks).
Asphyxia is the medical condition that results from long-standing hypoxia during or after the birth process. After a brief initial period of rapid breathing, the infant starts gasping then falls into secondary apnea that is unresponsive to stimulation. The heartbeat begins dropping, muscle tone is reduced, and the infant becomes flaccid. At that phase, spontaneous respiration cannot be established without proper resuscitation. And without it, multiorgan dysfunction follows, causing death.
If asphyxia lasts for a long time, Hypoxic-ischemic encephalopathy (HIE) may develop, leading to long term neuromotor sequelae and severe cognitive and developmental delay.
Resuscitation relies on the following steps:
-warmth, stimulation, and reposition: the baby is dried and placed under a radiant warmer, positioned on her side or back for better alignment of the upper respiratory tract. Tactile stimulation, usually through suction and clearing of the airway or gently rubbing the back or the soles, should stimulate the breathing. If not, time should not be wasted, and they should proceed with resuscitation.
-supplemental oxygen and evaluation: positive pressure ventilation is applied using a face mask and a self-inflating bag. Resuscitation should be done with room air as 100% oxygen, even with brief exposure. Thus, it should only be used when the heart rate is reduced to dangerous levels. Resuscitation is guided by the infant's evaluation every 30 seconds, through Apgar score or by checking the heart rate and respiration.
-Chest compressions (CC) and endotracheal intubation: CC rhythmic compressions applied to the sternum increase intrathoracic pressure. This acts like a mechanical pump that drives blood circulation to the vital organs. Endotracheal intubation is a hard skill and is required only in a small proportion of cases.
-epinephrine and volume expanders: after 30 seconds of proper chest compressions and adequate ventilation, if the heart rate remains below 60 beats/min, adrenaline is administered via the umbilical vein.
In the neonatal intensive care unit (NICU) or the delivery room, having an infant resuscitator allows more regular and consistent oxygen delivery with precise control of PIP and PEEP.
Respiratory failure and bradycardia
Respiratory failure happens when the lungs are unable to carry out an adequate gas exchange that matches the body's metabolic demands for oxygen. It results in decreased oxygen levels in the blood (hypoxemia) and oxygen deprivation in tissues (hypoxia), which causes damage and injury to the cells. Some tissues are very susceptible to hypoxia, like the brain tissue, that cannot survive more than 3 minutes of oxygen deprivation, due to its high metabolism and energy demands.
Infants are particularly prone to respiratory failure because their airways are small and easily obstructed, and their alveolar surface is much more limited than that of adults.
In the majority of cases, it manifests as a shallow, rapid breathing pattern. Without proper diagnosis or treatment, the respiration ceases, and the infant starts gasping for air or goes into apnea.
Bradycardia is defined as a heart rate less than 100 beats per minute for neonates and lower than 80 beats per minute for young children.
Bradycardia and apnea are among the common health problems in preterm infants, and they occur mainly because of the immaturity of the nervous system's vital reflexes. A slow heart rate in infants is also commonly associated with congenital heart defects (a deformity in the heart). When the heart rate falls into dangerously low levels, blood circulation to the peripheral organs is impaired. And thus, oxygenation of tissues decreases. The infant resuscitator can prevent hypoxia and hypoxemia of blood and tissue by delivering 100% oxygen. An infant resuscitator also does the work of mechanical ventilation for the thorax. Hence, it relieves some of the pressure on respiratory muscles.
Cyanosis is a term that refers to bluish discoloration of the skin and mucous membranes. Low oxygen levels in the blood are the cause behind it. Transient peripheral cyanosis (blue discoloration of the hands and feet) is benign in newborns. However, central cyanosis is a pathological emergency. And a diagnostic challenge for the clinician. Cyanosis usually indicates potentially life-threatening diseases, such as a congenital heart lesion (tetralogy of Fallot, pulmonary atresia), and it requires rapid assessment and the quick institution of resuscitation measures.
Complications of using infant resuscitator
The infant resuscitator can save the life of a newborn. Its use in a neonate unit reduces mortality and morbidity. Still, resuscitation, when not applied by an expert, can cause long-term damage and complications. Complications that arise from the use of an infant resuscitator are mainly due to mechanical ventilation or the administration of 100% oxygen.
Mechanical ventilation can result in chronic lung injury through excessive positive pressure (barotrauma) or extra volume transfer to the lungs (Volutrauma). These mechanisms can damage the lung through the overdistension of alveoli.
Oxygen toxicity: supplemental oxygen should be treated as a drug. Too much of it can also cause injury to the lungs, particularly in premature infants who have weak defense mechanisms against oxidative stress.
Brands and Market leaders
Neopuff™: FISHER & PAYKEL infant resuscitator is a t-piece resuscitator; its simple structure and design make its use easy and independent of the operator experience.
Ohmeda Medical: Ohmeda infant resuscitator can come alone or attached to the whole infant resuscitation system that also includes a warmer and access to suction and blended gases.
General specifications of infant resuscitators
- maximum pressure relief: 8 liter/min
- peak inspiratory pressure: at 5 liters/min (3-70 millibar) - at 15 liters/min (8-75 millibar)
- positive end-expiratory pressure: at 5 liters/min (1 to 6 millibars) -at 15 liter/min (4 to 17 millibars)
- accuracy of the manometer: plus, or minus 2% of the scale deflection.
Surviving the neonatal period is a real challenge for a newborn. Many factors and diseases (congenital disabilities, infections, prematurity) can cause the infant to be found in a critical situation that requires serious resuscitation. Having the right equipment for resuscitation can make the difference between life and death in those situations. The infant resuscitator is one effective, fast, and easy to use resuscitation apparatus that can assist with the respiration of the baby through safe inflation and ventilation of the lungs.