Transcript Other Therapies and Equipment

Therapeutic Gases, Respiratory Medications,
and Monitoring Equipment
Level 1
Mark A. Willing, RRT-NPS
Inhaled Medications



Bronchodilators
Steroids
Others
Bronchodilators

Albuterol sulfate (albuterol, Ventolin, Proventil)





Smooth muscle relaxant of small, peripheral airways
Onset of action within a few minutes
Peak effects in 15-20 minutes
Duration of effects 3-4 hours
Common side effects may include any of the below:







Tachycardia
Hyperglycemia
Hypokalemia
Lactic acidosis
Tremors
Increased pulmonary shunt
Stomach upset and reflux
Bronchodilators

Ipratropium Bromide (Atrovent)






Smooth muscle relaxant of larger, proximal airways
Onset of action within a few minutes
Peak effects in roughly 20-30 minutes
Duration of effects up to 4-6 hours
Has been demonstrated to have an additive effect with
albuterol
Common side effects may include:



Dryness of mouth and airway
Decreased secretions
Tremors
Bronchodilators


Albuterol and atrovent may be
combined into one medication and may
provide an enhanced bronchodilation
over using one or the other alone
Examples:


Combivent comes in a metered dose
inhaler
Duoneb comes as a liquid solution to be
used in a nebulizer
Inhaled Steroids


Flovent
Pulmocort







Decreases airway secretions
Decreases inflammation
May be immunosuppressive in large doses, over time
Vasoconstricts
Increases the effectiveness of bronchodilators
Onset of action roughly 2-3 hours
Duration of action 8-12 hours
Other

Racemic Epinephrine






Primarily used to increase the internal diameter of
airways through vasoconstriction
Also a potent, short-acting bronchodilator
Onset of action within a few minutes
Peak effects within 15 minutes
Duration of action roughly 2 hrs
Side effects may include:


Similar to high-dose albuterol
Repeated doses may begin to produce “rebound” effects
Other

Pulmozyme


Used to break DNA strands found in thick mucus,
thereby thinning the secretions for easier removal.
Side effects include:






Sore throat and/or vocal cords
Voice hoarseness
Rash or itchiness
Conjunctivitis (weepy, itchy, or gritty eyes)
Chest pain
Is corrosive to some materials found in ventilators
and requires special filters on the exhalation side
of the circuit.
Nitric Oxide

N-O









It is found throughout the body and is, among other many other things, responsible
for vascular smooth muscle relaxation.
When inhaled it travels to any open alveoli and then relaxes the blood vessels
supplying those alveoli.
It may decrease the severity of pulmonary hypertension in some patients.
Very short half-life (a few seconds)
Unstable. It reacts readily with oxygen to produce NO2 (the poisonous gas nitrogen
dioxide) and binds with oxyhemoglobin to produce methemeglobin (metHb). The
effects of metHb are similar to those of carbon monoxide in the blood.
Dosages are in parts per million (ppm).
20ppm is generally the starting dose, then is slowly weaned down after the FiO2
reaches 60% or less.
No clinically significant side effects have been demonstrated at the currently
recommended dosages.
Rebound pulmonary vasoconstriction may be a problem when weaning, but may be
counteracted with an increase in FiO2.
Helium-Oxygen Mixture






Helium-Oxygen (Heliox) starts out from the tank 80% He and 20% O2.

This is NOT the 100% helium used to fill party balloons

Breathing 100% helium has been known to cause neurologic damage from asphyxia
Oxygen is bled into the system to achieve the desired FiO2.
Helium, being the second lightest element known and being relatively inert, is ideal for
decreasing the work of breathing.
Breathing helium reduces the airways resistance and may allow more tidal volume at any
given ventilating pressure.
It can be delivered through a mask, CPAP prongs, or through a ventilator.
Clinical uses include:

Croup

Asthma

Lung tumors

ARDS, RDS, and other inflammatory lung processes

Tracheal and bronchial stenosis
Supplemental Nitrogen




Supplemental nitrogen may be used to lower the FiO2 below
21% when there is excessive blood flow to the lungs, creating
conditions favoring pulmonary vascular congestion.
Primarily used in the PICU for certain cardiac heart diseases pre
and/or post operatively.
The pulmonary vasculature constricts in response to a low PaO2.
Sometimes using less than 21% oxygen is needed to achieve
therapeutic efficacy.
Some of the early (1950’s) neonatal units used supplemental
nitrogen to lower the FiO2 below 21% to reduce the harmful
side effects of oxygen in premature neonates. There has been
a resurgence in the interest in this therapy for those premature
infants that still may be at risk for oxygen toxicity while
breathing room air.
Supplemental Oxygen







A highly reactive molecule needed for many biological reactions
Oxygen may only be utilized if there are adequate amounts of anti-oxidants to
counteract its potentially toxic metabolites…extremely premature neonates do
not appear to have developed an adequate antioxidant system. This system
develops after 32-34 weeks gestation
Inadequate and excessive amounts of oxygen produce toxic metabolites which
damage cells
An “all things in moderation” strategy must be used to maintain oxygen
saturations within normal physiologic levels, which has yet to be determined
Fetal cells are genetically designed for oxygen saturations of 30-80%, anything
more or less than that may cause damage to the cells, especially within the first
few weeks of life.
Unfortunately, greater than 70% oxygen saturation may be needed for
extrauterine life and weight gain
Oxygen and its metabolites have been implicated as the root cause of nearly all
the common mortality and morbidity seen in premature neonates.
Transcutaneous CO2/O2
Monitoring





A modified set of blood gas electrodes are placed on the skin and tissue measurements are
obtained.
The site is warmed:

Typically 41-42* C

The warming increases perfusion to the site through vasodilation of the local blood
supply

Gases diffuse from the blood vessels and tissues through the skin and into the
electrode for measurement
They are perfusion-dependent in their accuracy

Placing the warmed electrode on the skin of a patient with poor perfusion may cause
local tissue damage

The accuracy of the reading is severely compromised
They should only be placed on areas where there is an abundance of soft tissue

Do not place on a bony area
They should not be placed near an infection site

The warming of this area may increase the metabolism of damaged tissue creating
further damage

The accuracy of the reading is severely compromised
End-tidal CO2 monitoring





Not often used in the NICU, but common in the PICU,
OR, and adult ICUs
May also be used as part of a multi-channel
pneumogram to assess the presence of gas exchange
compared to chest wall movement
Exhaled gases are analyzed for the presence of CO2
In larger patients, gives a relatively accurate, breathby-breath measurement of CO2
May be used for ventilator management and
monitoring blood gas status during a surgical
procedure
Pulse Oximeters





Work on the principle that hemoglobin bound with oxygen will reflect light differently than
hemoglobin without oxygen bound to it.
A high-intensity light is emitted through the tissues and then read by a receiver on the other
side of the appendage (ear, finger, wrist, etc.)
The percentage of hemoglobin bound to oxygen is compared to hemoglobin without and
then calculated as a percentage (93%, 98%, etc.)
Does not recognize the difference between normal oxyhemoglobin, met-hemoglobin, and
carbon monoxide-hemoglobin
Accuracy may vary significantly depending upon:

Skin pigments, bilirubin, body art, finger nail polish, etc.

Certain dye-containing medications

Abnormal hemoglobins (including fetal hemoglobin)

Ability to “find” the pulse

Ambient light

Degree of oxygen desaturation

Generally not accurate below 85% unless specifically calibrated for low oxygen
saturations, which most are not. Documentation of oxygen saturations below
85% should be documented with the presence of a skin color change or not.