Humidification and aerosol 2014

By subtracting the actual amount from 44 mg/L., the humidity deficit can be calculated. For example, at 23 degrees C. the potential absolute humidity (or capacity) is ____

21 mg/L

Pulmonary complications of uncompensated humidity deficits occurring with intubated patients may occur when absolute humidity drops below ______

30mg/L.

In order for gas to be 100% saturated with water vapor at normal body temperature, it must contain how many milligrams of water per liter?

44 mg at normal conditions

Your patient has a temperature of 98.6 degrees F. In order to saturate the inhaled air, how much absolute humidity must be provided?

44 mg of water vapor per liter.

If a patient breathes through his or her nose _____ of larger particles will deposit above the larynx

99%

A patient has a face tent on for the delivery of aerosolized oxygen. Her secretions are still too thick to be easily coughed out (expectorated). What would you recommend?

A heated aerosol mask provides increased relative humidity which will help to reduce the humidity deficit.

Your patient's air-entrainment nebulizer (large volume nebulizer) is not putting out as much aerosol as it was a short time ago. What could be the problem?

A nebulizer will fail because of too little water in the reservoir, a clogged jet, or a clogged capillary line to the reservoir.

The following statement about aerosols deposition are true

A. Inspiratory flow rate affects particle deposition in upper airways B. Breath-hold period increases deposition in peripheral airways C. Partial deposition in peripheral airways occurs by settling D. Particle deposition in upper airways occurs by inertial impaction

The baffle in a nebulizer serves the purpose of breaking up aerosol particles into smaller ones.

A. Surface of water B. The sides of the container c. Sphere placed in path of the aerosol's flow d. Bend in the aerosol tubing

Saturated air at body temperature would have what characteristics?

At 37 C and 760 mm Hg, each liter of gas will hold 44 mg of water vapor which exerts a vapor pressure of 47 torr.

In order for gas to be 100% saturated with water vapor at normal body temp how many milligrams of water per liter must it contain

At 37 degree C each liter can hold 44 mg of water vapor

Which device employs a jet of compressed gas passed through a restricted orifice to create a therapeutic aerosol?

Nebulizers

What is the minimum absolute humidity that a gas delivered to a patient's upper airway should have?

No less than 12 mg/L

All of the following statements are accurate regarding the aerosols route for drug administration

-patient cooperation is necessary for optimum delivery - the aerosol route is a potential source of infection - the aerosol route results in a rapid therapeutic effect

What techniques can maximize aerosol deposition with a MDI

Slow deep inspiration a breath hold at the end of inspiration

A large-volume jet nebulizer is operating on 70% 02 at 12 LPM. You observe that the aerosol comes out only intermittently and that there is a bubbling sound in the system. What would you do?

The buildup of water had created an obstruction to the flow of aerosol out of the tubing. The tubing should be drained into a waste container - NOT back into the sterile reservoir.

What is the result when a liter of air that is fully saturated with water vapor at room temperature is warmed to body temperature?

The relative humidity will decrease because the ratio of absolute humidity to capacity has become smaller.

What does enlarging the Venturi port size on a nebulizer results in?

Total flow would be increased and the resultant FIO2 would be lower because of more room air being entrained

What device is not suitable for drug delivery because it can alter the chemical structure of the drug

Ultrasonic nebulizer

______ is able to produce a very dense aerosol at an extremely high output. It can achieve 100% body humidity without the need for heating the saline or water the tracheobronchial tree is saturated with super small aerosol particles that then _____ resulting in the increased body humidity

Ultrasonic nebulizer evaporate

In any given nebulizing device, which of the following may act to baffle the aerosolized particles?

a) the surface of the water, b) the sides of the container, c) a sphere placed in path of the aerosol's flow, or d) a bend in the aerosol tubing.

The following procedures are recommended to reduce the likelihood of contamination and infection with nebulizer reservoir systems:

a) use disinfected or sterile water only, b) discard reservoir water before refilling, and c) change nebulizer and circuit every 24 hours.

When an immersion heater is used, the increase in temperature causes an increase in _______ _____. There is also an increased risk of _______ as the heater is introduced into the liquid.

absolute humidity contamination

A patient who has a history of bronchospasm has an order for ultrasonic nebulization with 0.9% NaCl solution. Before administering this treatment, what would be your suggestion to the attending physician?

adding a pre treatment aerosolized bronchodilator

The respiratory therapist is operating a jet nebulizer on the 100% oxygen setting using a flow rate of 10 LPM to "drive" the jet. If he or she were to place this nebulizer on the 40% setting what would happen?

aerosol output would increase, because more air were entrained. Total flow would increase from 10 L to 40 L (on 40% , the air:oxygen ratio is 3: 1 ).

What are some complications of aerosol therapy?

aerosol-induced bronchospasm fluid overload in the infant or elderly patient, swollen secretions (after rehydration), causing an increase in the work of breathing, possible patient contamination if the reservoir water is infected (bacteria use the aerosol particle as a "vehicle.")

Patients with ___ _____should have medical gases delivered with 100% relative humidity at a temperature of 37 degrees (most textbooks state that 32-34 degrees C is close enough).

artificial airways

Which devices would you select to add water vapor to the delivered gas in a patient receiving oxygen via a partial re-breather mask?

bubbler

Another physician prescribes an ultrasonic nebulization treatment with a bronchodilator (0.5 cc albuterol). What would be your response to this order?

call the doctor because you can't give medication in a ultra sonic neb, the frequency will alter the composition of the drug

Regarding the ultrasonic nebulizer, what does the term piezoelectric refer to?

ceramic transducer of the ultrasonic nebulizer. Its function is to change electrical energy to sound waves which then break up the solution into small particles of aerosol.

The ultrasonic nebulizer is NOT suitable for drug delivery because the ultrasonic sound waves will alter the ____ ____ of some drugs.

chemical structure

Compared with other types of humidifiers, what is a major advantage of the Cascade humidifier?

claims that this heated device is capable of delivering 100% R.H. over a wide range of temperatures and flow rates.

What should the respiratory therapist assess to determine if there is adequate humidification of the inspired gas delivered to a patient with a tracheostomy?

consistency of sputum, color and whether it is dry or not

If the water in the ultrasonic nebulizer's couplant chamber is low, or if the medication cup is empty or nearly empty, the aerosol output will _______.

decrease

A patient receiving an aerosol treatment via a hand-held nebulizer powered by air complains of dizziness. What should the respiratory care student instruct the patient to do?

decrease respiratory rate and slow deep breaths

A patient is connected to a circuit that is utilizing a cascade humidifier; the tower was omitted during the assembly of the equipment. The temperature at the patient connection is 37 degrees C. The following two questions are in reference to this information: What changes in the patient's condition might be associated with the omission of the tower if the temperature at the patient's connection is 25 degrees C?

decreased efficiency of the humidifier and leads to an increase in humidity deficit (difference between body's need for humidity and humidity supplied by the device). Increased humidity deficit leads to thickened secretions, mucus plugging, airway obstruction, atelectasis, hypoxia and pneumonia.

What can help to minimize the danger of occlusion of a patient's endotracheal tube?

giving enough humidification

What factors influence aerosol deposition and penetration?

gravity, ventilatory pattern kinetic energy

The respiratory care practitioner should assess which of the following to determine adequate humidification of the inspired gas delivered to a patient with a tracheostomy?

hardened sputum in the airway

A physician would like to know how the ultrasonic nebulizer can adjust the particle size of the aerosol. What would be the most appropriate response?

nebulizer is determined by the frequency of the sound waves hitting the fluid and breaking it up and its not adjustable

What is the major function of a baffle in a nebulizer?

to break up larger particles into smaller ones

The size of the aerosolized particles that are generated by an ultrasonic nebulizer is believed to be determined by ____ ____ ____

unit ultrasonic frequency

A physician orders a potent bronchodilator drug for a patient via the aerosol route. What are 2 methods of delivery.

1. Small volume Nebulizer 2. Metered dose inhaler

A comatose patient is intubated and receiving 35% 02 with aerosol through a T -piece (Brigg's adaptor). While watching the patient breathe, you notice that during each inspiration the mist disappears from the downstream (distal end) of the T -piece. What would you recommend?

Adding 100 ml (about 6 inches) of aerosol tubing as a reservoir will help to maintain the patient's inspired 02 percentage

A patient with a tracheostomy is receiving continuous aerosol with a jet nebulizer operating on 40% oxygen at 8 LPM. If the patient's secretions are extremely viscid, what would be the most appropriate action for the respiratory care practitioner to take?

Addition of a heater to the system will result in an increase in air temperature and a corresponding increase in the amount of water the warmer air can hold.

Important information to keep in mind when an aerosol therapy is being administered would include what?

Airway obstruction may occur when/if dried secretions are re-hydrated. Upon addition of external water, inspissated secretions can swell and cause partial or total airway obstruction.

On the basis of particle size and desired deposition site, what aerosol delivery device should be selected for the treatment of croup (an inflammation of the throat area in small infants).

An atomizer is the simplest aerosol generator; it has no baffles and generates large particles.

Which kind of aerosol nebulizer is dependent on the effects of gravity and on the surface tension of liquid to expose the solution to the nebulization jet?

Babbington nebulizer

Nebulizers generate an aerosol on the basis of what principle

Bernoulli- describes the flow of fluid through a tube

A pneumatic nebulizer that produces an aerosol density of 35 milligrams per liter will supply what percentage of body humidity?

Body humidity (inspired gas saturated at 37 C) is 44 mg/L. 35/44 = 80%

During an aerosol therapy treatment, the respiratory care practitioner instructs a patient to hold her breath at the end of inspiration. What beneficial effect does this produce for the patient?

Breath holding , 10 seconds is the recommended time

A patient complains that his breathing is more difficult after an aerosol treatment with normal saline. What could account for the patient's complaint?

Breathing may be made more difficult if/when previously dry secretions absorb water, swell, and obstruct the airways.

What factors do not influence aerosol deposition and penetration

Ciliary activity is a function of the airway mucosa and affects clearance of aerosols and other inhaled irritants

There is a formula that can be used to calculate the appropriate catheter size to use based on the size of the ET tube:

ET tube size in mm divided by 2 = external diameter of suction catheter in mm. Suction catheter size in mm X 3 = French size. Example: size 8mm ET tube/2 = 4 mm suction catheter X 3 = 12 FR catheter

You notice that water has collected at the low point of the large-bore tubing of you patient's heated aerosol system. The aerosol is "puffing" out of the end of the tubing. What should the respiratory therapist do?

Excess condensate should be drained from the tubing AWAY from the patient and collected in a manner that does not contaminate the caregiver or the environment, such as wearing gloves to drain the tubing from the tubing into a waste receptacle.

The respiratory care practitioner notices that water has collected in the circuit being used for an intubated patient. The circuit is being humidified by a heated nebulizer. What action should the practitioner take?

Frequent monitoring of the delivery tubing and regular emptying of condensate are important to proper aerosol delivery

A patient is intubated and placed on a heated nebulizer system at FIO2 of 0.70. A thermometer is placed within 1 inch of the patient connection and reads 85 degrees F after 5 minutes. One hour later, the patient appears flushed and restless and complains of irritation. The respiratory care student checks the thermometer and it still reads 85 degrees F. The nurse notes that the patient's temperature has spiked from 97.9 degrees F. to 101 degrees F. What should the student do?

IMMEDIATELY REMOVE THE SOURCE OF HEAT replacing it with cool mist, until the defective heater can be replaced.

Calculate the humidity deficit if a humidifier is generating 30 mg/liter of water vapor.

In this case 44 mg/liter represents body humidity. If a humidifier generates only 30 mg/liter of humidity, it presents a deficit of 44-30 = 14 mg/liter.

How does an ultrasonic nebulizer work?

Plezoelectric crystals vibrate when electrically excited, creating ultrasonic waves in the liquid that generate geysers at the surface. The geysers release aerosol particles.

What is the mathematical formula relating relative humidity, absolute humidity (actual content) and maximum capacity (potential humidity)?

RH = AH/capacity

Croup is a condition of Subglottic edema caused by engorgement of inflamed vascularized tissue. What can reduce the swelling

Race ic epinephrine

What is the major function of a baffle in a nebulizer

Serves to direct large particles from suspension and allows them to return to the reservoir while smaller particles remain suspended in the gas and exit the nebulizer

The DeVilbiss (brand name) ultrasonic nebulizer has a flashing couplant indicator light. The therapist notices that the aerosol output has decreased from what it was earlier. What is the most likely problem?

The couplant light signals that the fluid in the couplant chamber is low, without this no aerosol will be produced

Suppose an ultrasonic nebulizer is putting aerosol out in short rapid puffs. What would be the most likely cause of this phenomenon?

When water accumulates in the corrugated hose (delivery tubing) the aerosol is no longer able to move freely.

Which of the following devices is LEAST appropriate for a patient with an artificial airway? a Babbington-type nebulizer a heated jet nebulizer an ultrasonic nebulizer a heated cascade humidifier. -a Passover humidifier

a Passover humidifier

A patient with an endotracheal tube in place is receiving oxygen enrichment via a heated all-purpose nebulizer. Water is collecting in the delivery hose. What action should the respiratory therapist take?

drain the delivery hose

You notice that water has collected at the low point of the large-bore tubing of your patient's heated aerosol system. The aerosol is "puffing" out of the end of the tubing.

empty out the tubing to prevent contamination.

A patient with COPD is receiving heated water aerosol via a jet nebulizer in order to aid in mobilizing retained secretions. While auscultating, you note an increase in rhonchi.

indicates that the secretions have been loosened, now the patient will need to cough them up. Coughing assistance and postural drainage techniques would be indicated.

In heated nebulizers, at what temperature should the reservoir temperatures be maintained?

intained slightly higher than body temperature so that by the time the air reaches the patient it will still be warm enough to hold sufficient moisture (32-34 C)

When a water-collection trap is placed within an aerosol hose, it must be placed along the most gravity- dependent portion of the circuit. Why is this

it can increase the airway resistance in the tubing, thereby reducing the efficiency of the nebulizer Less room air is entrained under increased back-pressure conditions.

When performing nasotracheal suctioning, what signs are used to indicate that the catheter tip has advanced into the trachea?

it is necessary to pass the catheter blindly through the vocal cords into the trachea. When the catheter tip advances through the cords, the patient's voice will become hoarse and whispery. The cough reflex is also strongly stimulated.

Given that a gas is saturated with 100% relative humidity at 32.2 degrees C. (90 degrees F.). As the gas cools to 26.7 degrees C. (80 degrees F.), what will happen to the relative humidity?

its ability to hold water vapor decreases

Aerosol therapy is not suitable as ______ term humidification for ventilator patients, because of the danger of fluid overload

long

Which device would be indicated when trying to assure adequate humidification of inspired gases to a spontaneously breathing patient with a tracheostomy tube?

look for one that incorporates heat and increased surface area or aerosol (because of the ability of the particles to evaporate into the tracheal gas).

Under what conditions will the water vapor pressure of humidity exert 47 torr ?

lower than 100% humidity, less than 44 mg/L and therefore exert less than 47 torr of vapor pressure.

A physician asks you to recommend a modality for a patient who is producing small amounts of thick, purulent sputum. What would be the best advice for treatment?

the use of a ultrasonic neb

Tracheal secretions tend to dry in an intubated patient when inspired air has what characteristics?

patient when the amount of water vapor in the inspired air is insufficient to meet the needs of the body

The pop-off valve is whistling on your patient's bubble humidifier to a 28% oxygen/air entrainment mask. What could be the problem?

pinching of the small bore O2 delivery tubing causes an increase in pressure within the reservoir.

Why should non-disposable humidifiers or nebulizers for oxygen delivery devices NOT be kept filled with water for extended periods of time?

risk of microbial contamination and subsequent growth of microbes in the system.

What is the ideal breathing pattern for maximal aerosol deposition and retention in medication delivery?

slow deep breaths and holding it at the end

The efficiency of any humidifier is related to which factor(s)?

surface area time of contact and tempurature

What effect will the accumulation of a large volume of liquid in the dependent portion of a large-bore delivery tube will have on a jet nebulizer system that is set to deliver an FIO2 of 0.40?

the FIO2 increases.

How does the addition of a heater to a large volume nebulizer increase in the relative humidity of the inspired gas?

the air temperature will also increase, resulting in an increase in the absolute humidity.

The tower has now been reinserted and gas is being delivered to the patient at body temperature. Which of the following statements is now correct about the delivered humidity?

the device is capable of delivering 100% relative humidity through a wide range of temperatures and flow rates.

Suppose that the doctor has prescribed ultrasonic nebulization with normal saline to a patient who is 5 days post-op and ambulatory (able to walk around). The respiratory therapist performs an assessment before the therapy (noting clear normal breathsounds). Following the therapy, the therapist notes that the patient is dyspneic (complains of shortness of breath) and wheezing, with a dry non-productive cough. What would you recommend to the doctor?

the treatment is causing the patient to have bronchospasms, discontinue the treatment

A patient's humidity deficit is going to be the smallest under which conditions?

when the inspired air temperature is near body temperature and the humidification device is heated.