Chapter 41 egans

What are the clinical objectives for oxygen therapy

- Correct documented or suspected acute hypoxemia - Decrease the symptoms associated with chronic hypoxemia - Decrease the workload hypoxemia imposes on the cardiopulmonary system

What affect does hypoxemia I have on the pulmonary blood vessel? What are the long-term consequences of this affects?

-Alveolar hypoxemia causes vasoconstriction of the pulmonary vessels. -if prolong this results in pulmonary hypertension, increased work of right heart, and eventually right heart failure

What is the Primary benefit of the infant incubator

Helps maintain a neutral thermal environment.

What is meant by a "vicious circle" in reference to oxygen toxicity

High FiO2 causes oxygen toxicity which causes shunting which results in lower PaO2 levels, which requires higher FiO2 levels for treatment

Under what circumstances is HBO indicated in cases of carbon monoxide poisoning?

History of unconsciousness, presence of neuropsychiatric abnormalities, cardiac instability, and carboxyhemoglobin 25% in adults (lower in kids and pregnant woman)

Nitric Oxide Therapy

Improves blood flow Reduces shunting Improved oxygenation Decreases pulmonary vascular resistance Initial does is 20ppm x 14days Dosage reduced to 6ppm at the end of 4hrs of initial therapy, as tolerated

What should never be attached to an air entrainment mask (AEM)

Bubble humidifier because the AEM works on laminar flow(use an LVN) and the bubble humidifier works on turbulent flow

What are some physiologic effects of hyperbaric oxygen therapy

Bubble reduction (Boyles law) Hyper oxygenation of blood and tissue ( Henry's law) Vasoconstriction Enhanced host immune function Neovascularization(Forming new vessels)

Helium oxygen therapy

Can decrease work of breathing for patients with airway obstructions Low Density (benefit) Must always be mixed with O2 Can be prepared at bedside

List six common acute clinical situations were hypoxemia is so common that oxygen therapy is usually provided

Carbon monoxide poisoning Cyanide poisoning shock trauma acute myocardial infarction post operative patients

What is the three-step process for confirming the proper operation of a blender

Confirm appropriate Air and oxygen inlet pressure Test the alarms by disconnecting each gas source Analyze at 100%

What are acute conditions in which HBO is indicated

Decompression sickness air/gas embolism carbon monoxide poisoning

What is Physiologic response of a healthy individual who is exposure to 100% inspired oxygen with an exposure time of 30-72hrs

Decreasing diffusing capacity

What is Physiologic response of a healthy individual who is exposure to 100% inspired oxygen with an exposure time of 25-30hrs

Decreasing lung compliance Increasing P(A-a)O2 Decreasing exercise PO2

What is Physiologic response of a healthy individual who is exposure to 100% inspired oxygen with an exposure time of 12-24hrs

Decreasing vital capacity

Air entreatment mask

Direct a high pressure O2 sources through a small nozzle or jet surrounded by the air entrainment ports

What are chronic conditions in which HBO is indicated

Enhance wound healing refractory osteomyelitis Radiation necrosis

During a section procedure a patient experiences tachycardia with PVCs. Which of the following could be responsible for this response

In adequate preoxygenation

What is a common problem with a low flow system

Inaccurate flow, leaks and obstruction, device displacement, and skin irritation

Describe the compensatory mechanisms of the cardio pulmonary system when faced with hypoxemia in the heart

Increase cardiac output: faster heart rate, increased stroke volume equals increase CO

The patient is receiving oxygen therapy from a non-rebreathing mask with a flow rate of 10 L per minute. The respiratory therapist observed the bag deflating with each inspiration. What action is indicated in this situation

Increase the flow to the mask

Describe the compensatory mechanisms of the cardio pulmonary system when faced with hypoxemia in the lungs

Increase ventilation: faster rate and increased depth

Air embolism

Is a complication that can occur with certain cardiovascular procedures, lung biopsy, hemodialysis, and central line placement, HBO can decrease the size of air bubbles which may otherwise reach the cerebral or cardiac circulation and can cause symptoms for certain death. Typical therapy for embolism involves immediate pressurization in air to 6 ATA for 15 to 30 minutes

Low flow system

Is a device that does not meet or exceed the patients demands(May meet if no leaks occur). This system provide supplemental oxygen delivery to the airway at a flow of 8L per minute or less

Carbon monoxide poisoning

Is the number one poison gas sources, it accounts for about half of all poisoning death in the USA. If a patient breaths air, it takes more than five hours to remove only 1/2 of the carboxyhemoglobin in the blood. Breathing 100% oxygen reduces this half life to 80 minutes. The half-life of carboxyhemoglobin under HBO at 3 ATA is only 23 minutes

Why is the hood the best method for delivering oxygen to an infant

It only covers the head and leaves the body free for nursing care. (Always use the heater)

List three basic ways to determine when a patient needs oxygen

Lab evidence-documenting includes hemoglobin saturation and PO2 Patient specific condition or problem Bedside assessment

What is the general rule that can be applied to prevent oxygen toxicity?

Limit exposure to 100% oxygen to less than 24 hours whenever possible. High FiO2 is acceptable if the concentration can be decreased to 70% within two days and 50% or less within five days.

Oxygen toxicity can affect what two organ systems?

Lungs and central nervous system

What harmful consequences can occur when flow rate in the hood are too

May generate harmful noise level and cause additional stress to the infant

Low-flow Systems Include

Nasal cannula, nasal catheter, transtracheal catheter, reservoir cannula, reservoir mask, non-rebreathing mask

Patient is to receive a mixture of helium and oxygen. Which of the following delivery devices would be appropriate

Non-rebreathing mask

What is Physiologic response of a healthy individual who is exposure to 100% inspired oxygen with an exposure time of 0-12hrs

Normal pulmonary function Tracheobronchitis Substernal chest pain

Indications for helium

Obstruction of various causes; post extubation stridor in pediatric

During what time after birth is a preemie likely to develop retinopathy of prematurity (ROP)

One month

If an air entreatment mask does not meet or exceed patients need you can

One. Add Open reservoir to expiratory side of T tube Two. Provide Inspiratory reservoir with one way expiratory valve-open (non-rebreathing reservoir circuit) Three. Connect two or more nebulizers together in parallel (WYE) Four. Set nebulizer to Low concentration and bleed in oxygen into delivery tubing, analyze and adjust

What are two primary factors that determine the harmful effects of oxygen

PO2 Exposure time

What are the threshold criteria for defining hypoxemia in adults according to the AARC clinical practice guidelines?

PaO2 <60mmHg SaO2 <90%

Because you can't tell exactly how much oxygen the patient is receiving at any given moment from the cannula or any low flow device, how can you assess the effects of administering the drug?

Patient clinical response

nitric oxide (NO)

Prevents pulmonary hypertension (increases bp in pulmonary system) NO is normally produced in small amounts within the human body and activates guanylate Cyclase, which catalyzes the production of cyclic guanosine 3' 5' mono phosphate (cGMP)

What is oxygen toxicity

Prolonged exposure to high concentrations of supplemental oxygen, Oxygen pushes nitrogen out of the alveoli and blood vessels dilate.

A patient with history of carbon dioxide retention is receiving oxygen at 6 L per minute via nasal cannula. He is becoming lethargic and difficult to arouse. In regards to the oxygen delivery, what changes would you recommend?

Reduce the flow to 2 L per minute and obtain an ABG

exudative

Relating to the oozing of fluid and other materials from the cells and tissues, usually as a result of inflammation or injury

What is the primary disadvantage of trans tracheal catheter

Requires a surgical procedure and maintenance

What are severe clinical signs of hypoxia in respiratory, cardiovascular, and neurologic

Respiratory- Tachypnea, Dyspnea, Cyanosis Cardiovascular-Tachycardia and then eventually bradycardia, hypertension and then eventually hypotension Neurologic- somnolence (sleep), confusion, distressed appearance, blurred vision, tunnel vision, loss of coordination, impaired judgment, slow reaction time, manic depressive activity, coma

What are mild to moderate clinical signs of hypoxia in respiratory, cardiovascular, and neurologic

Respiratory- Tachypnea, Dyspnea, Paleness Cardiovascular- Tachycardia, Mild hypertension, Peripheral vasoconstriction Neurologic- Restlessness, Disorientate, headaches, Lassitude (lack of energy)

What are patient factors in selecting oxygen therapy equipment

Severity and causes of hypoxemia Patient age group Degree of consciousness and alertness Presence or absence of tracheal airway Stability of minute ventilation Mouth breathing vs nose breathing patients

What is the biggest hazard in the home setting?

Smoking

What is a cute Hypoxemia?

Sudden decrease of oxygen in blood

Describe how oxygen can cause atelectasis

The FiO2 levels above. 50 cause atelectasis by washing nitrogen out of poorly ventilated units. The oxygen diffuses into the blood, and the alveoli; collapse

What is the therapeutic benefit of nitric oxide

The therapeutic benefit of inhaled NO stems from improved blood flow to ventilated alveoli. The result is a reduction in intrapulmonary shunting, improvement of arterial oxygenation, and a decrease in pulmonary vascular resistance and pulmonary arterial pressure

What is a reservoir cannula

This device is designed to conserve oxygen, there are two types: Reservoir- operate by storing approximately 20 mL of oxygen in a small membrane reservoir during exhalation Pendant reservoir- helps overcome esthetic concerns by hiding the reservoir under the patient's clothing on the anterior chest wall

Nonrebreathing reservoir circuit

This requires an elaborate combination of equipment and supplies: -blender - humidifier - reservoir bag - Fail safe valve - one-way valve

What is the overall goal of oxygen therapy

To maintain adequate tissue oxygenation while minimizing cardiopulmonary work

What effects does oxygen toxicity have on the central nervous system

Tremors, twitching, and convulsion, tend to occur only when a patient is breathing oxygen that pressure is greater than one ATM (hyperbaric pressure)

How can you reduce risk of absorption atelectasis

Use the lowest FiO2 levels, Identify at risk patient, use hyper inflation therapies to avoid or reverse the atelectasis

When should you attach the cannula to a bubble humidifier

When flows are greater than 4 L per minute

High flow systems

Will meet or exceed the patient's demand, if it delivers 60 L per minute or three times Of patient minute ventilation

How can you reduce the risk of ROP?

by maintaining PO2 level less than 80 mmHg And minimizing other factors such as acidosis

high flow nasal cannula system

can deliver both FiO2 and relative humidity greater than 90% are using heated, humidified O2 flows up to 40 L per minute

In what acute cardiac condition is oxygen therapy especially important?

myocardial infarction because when the heart is stressed or damaged, it is especially important to reduce the workload

The newborn requires oxygen therapy. Which of the following methods of delivery would you select?

oxygen hood

What is the fire triangle?

oxygen, fuel, heat

Blending system

separate pressurized air and O2 sources are input, and the gases are mixed either manually or with a precision valve(blender). This system allows precise control over both FiO2 and total flow output

Trans tracheal catheter

small tube inserted surgically through the base of the neck used for pt on long term O2 therapy and is secured by a chain necklace. (Delivers O2 right to the trachea)

Hyperbaric oxygen therapy (HBO)

therapeutic application of O2 at the pressures greater than 1 atmosphere (or 760 mmHg).

High-flow systems include:

•Air entreatment mask •Blending system •high flow nasal cannula system

A patient is receiving 40% oxygen via air entrainment mask with a flowmeter said it 8 L per minute. What is the total flow delivered to the patient?

32 L per minute

Correction factors for helium

80:20-1.8 70:30-1.6 60:40-1.4

What is retinopathy of prematurity?

A cause of blindness in premature infants because too much O2 is administered and to much O2 causes the retinal vessels to constrict and leads to blindness

What specific type of COPD patient is likely to experience depression of ventilatory drive while breathing oxygen?

A small percentage of severe COPD patients with carbon dioxide retention tend to ventilate less when exposed to moderate to high levels of oxygen.

The potential use for inhaled nitric oxide

ADRS Persistent pulmonary hypertension of newborns Primary pulmonary hypertension after cardiac surgery Cardiac transplant Acute pulmonary embolism COPD Congenital diaphragmatic hernia Sickle cell disease Testing pulmonary vascular responsiveness

bronchopneumonia

Acute inflammation of the lungs and bronchioles, characterized by chills, fever, high pulse and respiratory rate, Bronchial, cough with purulent bloody sputum, and chest pain

Nitric oxide has been approved by the FDA for use

An conduction in conjunction with medical ventilation, in treating terms and near terms (greater than 34 weeks) neonates with hypoxic (type one) respiratory failure with associated pulmonary hypertension

In what care setting are reservoir cannulas usually use?

At home or ambulatory patient who needs increased mobility

How can you tell if a non-rebreathing mask (has valves) has an adequate flow rate?

Bag does not fully deflate on inspiration

An 80/20 mixture of helium and oxygen is administered. And oxygen flow meter is set at 10 L per minute. What is the actual flow delivered to the patient?

18Lpm

A patient requires a flow of 40 L per minute to meet his inspiratory demand for gas. He is to receive oxygen via a Venturi mask set at 24%. What is the minimum setting on the flowmeter to produce the appropriate flow?

2 L per minute

What is the minimum flow for a hood? And why?

7 L per minute to prevent accumulation of CO2