Oxygen may be the most misunderstood drug in use today. Oxygen, in the eyes of many, is a wonder drug that can cure many problems. The purpose of this section is to look at oxygen as a drug that must be used with as much prudence as any other drug. We will also discuss the techniques of airway management such as Intubation and suctioning of neonates. Oxygen has side effects and complications that may further injure the lungs of the compromised patient. Some of the most common complications include: Retinopathy of prematurity, oxygen toxicity leading to bronchopulmonary dysplasia, cerebral vasoconstriction, and fire hazard.
Oxygen Delivery Methods
- Oxygen blenders and Flowmeters
The oxygen blender is the usual starting point for the administration of various concentrations of oxygen. The blender is first connected to a source of oxygen and air. The gases go through a series of regulators to lower the pressure to a workable level and then are mixed to achieve the desired concentration of gas.
The practitioner determines the appropriate concentration of oxygen ranging from 0.21 to 1.0 percent. The blended gas passes to the exterior of the device where a flowmeter is used to direct the proper flow of gas to the patient. Although most oxygen blenders indicate an approximate oxygen percentage on the mixture dial, few will be entirely accurate. Watch short video on the oxygen blender. You will gain a better understanding of its use in delivering oxygen to neonates (total time 2:47 minutes).
If a precise oxygen percentage is desired, it is essential that an oxygen analyzer be placed in the system to monitor delivered oxygen percent. The only precaution is to place the analyzer in the system proximal to the humidifier to prevent moisture from entering the device resulting in erroneous readings. The analyzer should be calibrated at two levels prior to use: room air (21%) and (100%) to assure accuracy. Watch this short video on how to calibrate and oxygen analyzer (total time 3:58 minutes).
- Oxygen Hood
Is a clear, plastic hood that fits over the infantâ€™s head. It provides an oxygen rich environment for the patient with relative ease and comfort. Oxygen hoods are generally used with oxygen percentage less than 50%. The hood can also be used with infants requiring more than 50% oxygen; however, it is difficult to maintain a consistent concentration above that level. An infant requiring high levels of oxygen should be closely assessed for signs of respiratory distress or other problems and other therapies may be indicated. Due to the layering effect of the oxygen in the hood, the oxygen percentage should be monitored at the level of the patientâ€™s face to ensure an accurate reading. The flow rate in the device is equally as important as the oxygen percentage. An inadequate flow rate (too low) could result in the accumulation of excessive CO2 retention in the hood. The flow rate should be maintained at 7L/min or more to avoid this problem.
- Oxygen nasal cannulas
Cannulas are used on patients with chronic oxygen need. Chronic oxygen use is often associated with bronchopulmonary dysplasia (BPD). Cannulas can also be used as a tool to wean the patient from an oxygen hood, gradually weaning the patient to room air. Flow rates used on the neonatal patient are usually less than 1L/min. A flowrate greater than 4L/min may lead to nasal mucosal drying and epistaxis and should be used cautiously.
Pediatric and neonatal cannulas are available from various manufacturers. The pediatric nasal prongs are shorter in length and smaller in diameter compared to adult cannulas. The neonatal cannula has prongs that are even shorter and smaller, accommodating the even smaller neonatal nose and face.
- Positive Pressure Ventilation (PPV)
Oxygen delivery via a resuscitation bag mask valve is not considered to be a day- to-day delivery method for oxygen, but is more commonly used during emergencies. Two types of bags are commonly used in clinical practice: self-inflating and flow inflating. A new type of resuscitator, called a T-Piece device is beneficial in achieving controlled peak inspiratory pressure (PIP) and consistent positive end expiratory pressure (PEEP).
Self-inflating bags are designed to reinflate following decompression. The gas delivered to the patient is entrained into the bag on each reinflation. With a proper reservoir attached and sufficient oxygen flow, most self-inflating bags can achieve oxygen percentages between 80% and 100%. Without a reservoir and inadequate flow rates, the oxygen percentages are unpredictable and not appropriate for most situations.
Flow-inflating bags have the advantage of providing the percentage of oxygen that is used to power them. Oxygen percentages up to 100% can be achieved simply by using pure oxygen to inflate the bag. Oxygen can be administered either by blow-by or by the use of a pressure mask over the nose and mouth. The Use of a resuscitation bag for a neonate or pediatric patient require the use of a pressure manometer in order to measure the inflation pressures to prevent airway trauma.
The T-piece resuscitator has gained popularity in the delivery room and is the preferred manual ventilation device in some institutions. The T-piece has the advantage over the self-inflating bag in that it can deliver free-flow oxygen through the mask and can be used to deliver consistent pre-set inspiratory pressure and positive end-expiratory pressures (PEEP).
You will learn more about the various types of resuscitation devices when you take the neonatal resuscitation program (NRP) through your local hospital.
In the past PPV has been performed with bag mask valves however, the respiratory rate and depth of breaths is mainly determined by the efforts of the individual preforming the task. New evidence revealed that using a bag mask valve device on neonates is too risky, and many hospitals are making the transition from bag mask valves to the use of T-Piece methods of positive pressure ventilation.
An infant requiring resuscitation has the essential need for oxygen, however, prematurity and diseases such as respiratory distress syndrome can make the requirements complex. As respiratory therapists we must protect underdeveloped or compromised lungs. The T-Piece resuscitator provides the therapist with the following factors which allows more efficient resuscitation:
1. Controlled Peak Inspiratory Pressure (PIP) is the maximum inspiratory pressure that delivers a breath. The objective in delivering PIP is to inflate and recruit alveoli to achieve gas exchange at the lowest possible pressure.
2. Consistent Positive End Expiratory Pressure (PEEP) is the pressure in the lungs at the end of expiration. PEEP is also referred to as CPAP. Consistent PEEP allows gas to remain in the lungs after the patient expires to help establish functional residual capacity and increase the blood oxygen level.
3. Ideal breath rate – 40 to 60 breaths per minute is what is suggested by Neonatal Resuscitation Protocol. The T-Piece resuscitator allows the therapist to easily provide this rate using just their finger placed on the tee for each breath.
4.Maintain a seal in an infant that is not intubated. The T-piece allows the therapist to use one hand to deliver the breaths freeing the other hand to provide an adequate seal by keeping the mask in place.
5. Fraction of inspired oxygen (FiO2) the T-Piece allows an FiO2 from 21% to 100% oxygen to be delivered to the patient. This can be delivered as blow-by or free flow oxygen, or used concurrently with PPV.
Depending on the type of T-Piece resuscitator your facility uses, you may hear this called a Neo-Tee (Mercury Medical) or more commonly a NeoPuff (Fisher & Paykel). The T-Piece resuscitator system can be used to deliver exact pressures and incorporates a manometer which measures and displays the pressures on a dial.
Watch this short video before you continue in the lesson. This video will provide you with an understanding of how to set up a Neopuff for use (total time 5:46 minutes).
Blowby oxygen: If the infant is breathing yet continues to be cyanotic (blue) probably will require oxygen therapy, the NeoPuff can be used to blow oxygen past the patientâ€™s face (the bag-mask valve cannot be used to give blowby oxygen). The following steps should be followed when administering blow-by oxygen to a neonate.
- Place mask or the end of the oxygen tubing near babyâ€™s mouth and nose (Do not place the mask on the baby’s face, just NEAR the face)
- Occlude PEEP valve with your finger and hold it there
- Oxygen should now be blowing by the patientâ€™s face
- Adjust oxygen as required to maintain desired SpO2 based on gestational age (see table below)
How to give PPV with the NeoPuff?
If the infant is not breathing adequately, and become bradycardic (heartrate less that 100), the following steps should be followed:
- Place mask over the babyâ€™s mouth and nose if patient is not intubated
- Place a Briggs T adapter to the patient endotracheal tube id intubated
- Resuscitate by placing and removing thumb over the PEEP cap to allow inspiration and expiration.
- Inhalation occurs when you occlude the PEEP cap
- Exhalation occurs when you release the PEEP cap
- Give 40-60 breaths per minute
- Continue efforts until heart rate is greater than 100 and breathing is adequate
Desired patient outcomes with the use of PPV
- Bradycardia subsides
- Improved Color with oxygenation
- Spontaneous respirations are present
- Increased muscle tone
Trouble Shooting the NeoPuff
- Assure that a good seal is present without leaks
- Make sure PIP is adequate based on practitioners orders
- Assess the patients respirations
- Reposition infant if leaks or inadequate pressures are noted
Administering CPAP with the NeoPuff
If infant heart rate is above 100 and breathing remains labored, CPAP may be initiated following the steps below:
- Place mask over the babyâ€™s mouth and nose if not intubated
- If the patient is intubated fit the Briggs T adapter to the endotracheal tube
- Do not occlude the PEEP valve to allow the patient to breath spontaneously while providing CPAP
- Verify proper operation by observing the pressure manometer indicating prescribed PEEP setting on exhalation.
Indications for NeoPuff compared to Bag Mask Valve
- Evidence shows the NeoPuff is the best way to ventilate neonates
- Less delivered pressure avoiding barotrauma (pneumothorax)
- Consistent Pressure preventing Hyaline Membrane Disease*
- Inspiratory time and respiratory rate can be controlled by a finger instead of whole hand
- Less stress on caregiver (donâ€™t have to worry about giving too much or too little pressure)
*Evidence shows that inconsistent pressures from bag mask valves actually cause bruising in the neonate airway and can result in further complications for newborns making them extremely difficult to treat. The Neopuff gives constant, equal breaths that are much easier for the infant.
When using the bag mask valve the oxygen percentages cannot be regulated 100% oxygen is usually delivered. The NeoPuff allows you to adjust the FiO2 from 21% to 100%. A growing number of literatures have proven you shouldnâ€™t use 100% oxygen for newborn and infants; it can be detrimental to their health.
Several studies have linked 100% oxygen (even for as little as ONE minute) to:
- Cellular death
- Delayed development of oxygen sensing tissues
- Oxygen radical disease of neonate (blindness)
Because oxygen can be responsible for many complications low percentages should be used when possible and, titrate to higher levels when need to better oxygenate the patient. The Physician must recommend all oxygen changes. It is important to monitor blood and tissue oxygenation (SaO2 and PaO2) to assure that excessive oxygen is not being administered resulting in complications.
The recommended goals of oxygenation:
40 or >
Intubation (Airway Management)
Endotracheal intubation is a generally safe method of airway management in infants and children, even when used for extended periods. The infantâ€™s age or weight can be used to estimate the proper endotracheal tube size and depth of insertion. If the tube is too small in diameter it may cause a leak with decreased delivered minute ventilation, high resistance and increased spontaneous work of breathing for the child. An inappropriately large tube can cause mucosal and laryngeal damage that is evident after extubation, resulting in upper airway obstruction. Most neonatal and pediatric tubes are uncuffed. This is because the narrowest part of the infant and small child is the cricoid cartilage.
When the appropriate size tube is used, the fit of the tube in the airway â€œsealsâ€ the airway enough so that adequate ventilation can be maintained. Because the tongue is large and the epiglottis is anatomically high in infants and small children, many practitioners find the Miller (straight) blade best for the intubation procedure. Infant tubes are small and can be easily kinked or obstructed. Also, slight changes in the position of the infant’s head can result in improper positioning of the tube in the airway, that will prevent ventilation and oxygenation.
A primary duty of a respiratory therapist is patient airway clearance. Patients often have airway problems that hinder the normal clearance of airway secretions, that may lead to respiratory distress. The intubated patient has a decreased ability to remove airway secretions spontaneously and must be aided by the practitioner. Secretions that block the airway will increase resistance and subsequently increase the work of breathing. As airway resistance increased, airflow is diminished and ventilation decreases. Proper suctioning must be done in a manner that does not compromise the clinical status of the patient or the sterility of the airways.
Oral, nasal, and tracheal suctioning should be done when indicated. The basic indication for suctioning is the need to remove secretions. The secretions may be located in the trachea, pharynx, mouth, or nose. Intubated patients may require frequent suctioning of the endotracheal tube (ETT) to preserve its patency.
Suctioning through the ETT should be performed on an as needed basis. Due to its effect on the patientâ€™s ventilator status, suctioning should be done at least 20 minutes before a blood gas sample is drawn.
The first task in preparing the airway for suctioning is the preparation of the equipment. Select the appropriately sized suction catheter for your patient. The technique of inserting the suction catheter into the ETT until resistance is felt may lead to trauma of the tracheal mucosa. To avoid injury, the suction catheter should be inserted only to the tip of the ETT. The proper catheter insertion distance is measured by noting the cm mark on the exterior ETT, which corresponds to the level of the adaptor. The vacuum pressure should be adjusted by occluding the end of the suction tubing and adjusting the vacuum to -50 to -80 mmHg for neonates and -80 to -100 mmHg for pediatric patients.
The major hazard related to tracheal suctioning is bradycardia. Bradycardia is defined as a heart rate below 100 bpm. In the neonate, a heart rate below 100 indicated lack of proper oxygenation and a decrease in cardiac output secondary to decreased contractility of the myocardium. It is a serious hazard that requires rapid care by the practitioner. Tracheal stimulation can cause a vagal response by the vagus nerve, this leads to bradycardia. Vagal stimulation may be lessened by limiting the amount of time that the suction catheter is in the tracheal or pharynx. Insertion and removal of the suction catheter should last no longer than 10 seconds.
For this assignment, please write a paper of at least 500 words that discusses preparation for an intubation on a neonatal patient. What therapies are commonly used before a baby is intubated? How do we know when to intubate and mechanically ventilate a patient?