Unit 3 Weeks 9 Flashcards
Pulse Oximetry SPO2
- Percent of of O2 bound to hemoglobin and measured with infrared source
- Measurement of arterial oxygen saturation SpO2
- Threshold above >90%
Limitations to Pulse Ox
- Low perfusion or circulation: not enough RBC’s or not enough of regular pulse passing under the sensor to accurately calculate the saturation so they use a formula based on light
- Anemia
- Nail polish b/c it doesn’t let light through
- Fluorescent lighting b/c flickers and overlapping light wavelengths that interfere with the signal from the infrared
- Dark skin b/c contains more pigment and melanin absorbs high affecting the ability of the pulse ox to accurately detect light transmitted through skin
- Jaundice b/c excess bilirubin in jaundice can also absorb light and interfere with signal
-Arrythmias b/c it can lead to variations in strength and regularity of the pulse signal make it challenging for the pulse ox to consistently and reliably detect changes in light absorption to calculate O2 saturation
Normal Adult Ranges:
1.HR
2.Systolic BP
3. Diastolic BP
4. RR
5. O2 saturation
- 50-100BPM
- 85-140 mmHg
- 40-90 mmHg
- 12-20 Bpm
- > 95% on Fio2
Invasive Monitoring Arterial Lines
- Continuous BP management
- Hemodynamic Monitoring
- Frequent ABGs
- Drug Administration
- Usually placed in the radial artery or the femoral artery
NORMAL MAP 70-110 mmHg - MAP lower than 60 indicates poor perfusion
Mobilizing a patient with an A-line
The transducer that reads BP always needs to be at the level of the right atrium for accurate readings
- If it is to high the BP will read to low and if its to low the BP will read to high
Central venous Line
- Measures central venous pressure or right atrial pressure
- Allows IV access for medication administration
- Tunneled is for long term - burrowed under the skin prior to actually entering the actual vein can help with decrease in infection risk
- Non-tunneled is for short term
PICC Central venous line
- PICC line is placed in cephalic, basilic, or brachial vein using sterile techniques
- PICC still runs up to superior VC or at the right atrium
CVP or PICC Precautions
- They need to remain STERILE
- Usually well covered near skin insertion
- secure ends well before mobilizing
- be aware of the location and avoid dislodging
- Use precautions when femoral PICC used
Swan Ganz-Pulmonary Artery Catheter
- Surgically inserted catheter
- Through the central vein
Threaded through the right atrium and ventricle into pulmonary artery - Continuous all the way through the vena cava into and through the right atrium through the right ventricle all the way to the pulmonary artery
Measurement of blood pressure to locate/monitor heart failure:
- Central Venous pressure
- Right atrial pressure (gives an idea of venous return and resistance to flow into right side of the heart)
- Pulmonary artery pressure ( Helps determine problems like pulmonary hypertension/resistance to flow through the lungs)
- Pulmonary capillary wedge pressure ( PCWP= measures/estimate left sided heart filling pressure and calculate vascular resistance)
Pulmonary capillary wedge pressure=
It measures the left side heart function
- Pulmonary capillary wedge pressure= LEFT side heart filling pressure and can determine states of pulmonary circulation, detect pulmonary hypertension and estimate filling pressure of L atrium
- Left atrial filling
- Filling pressure of L venticle
- indirect assessment of L ventricular function
Uses of Swan Ganz Catheter
- monitoring heart function post surgeries
- Diagnosing chronic heart failure
- Differentiating causes of pulmonary edema- Guiding diuretic dosing to manage fluid overload
What does elevated PCWP mean
Pulmonary capillary wedge pressure
- pulmonary hypertension
- Indicates resistance to flow into the left ventricle
Can you mobilize a patient with Swan Ganz
Yes
- standard dressing and immobilization technique of the skin prevents catheter dislodgement during ambulation + increases physical activity helped patients psychological + physical benefits
What are the complications of Dislodgement of the Swan Ganz
- Serious arrythmias
- pulmonary artery rupture
- Pulmonary valve damage
- infection
Invasive Monitoring Temperature
- Swan Gaz
- urinary catheters
- Nasopharyngeal
- rectal probe
Only when comatose, intubated, confused
Intracranial Pressure
- Used for neurological trauma
- Increased ICP causes decreased perfusion of the brain
-Low CO2 levels can help control increased ICP - Drain or shunt may be placed to control ICP
- mobilization can quickly change ICP
What is the most common device for O2 delivery
Nasal Cannula
Nasal Cannula
- Lowest Level of Support
- Flow rates between 1 and 6 L/min
- Humidity is needed when rate is >4 L/min
RULE OF 4’S
EXAMPLE: 1 L/min = 24% approximate FiO2
2 L/min= 28% approximate FiO2
3L/min = 32% approximate FiO2
Face Mask
- 5-10 L/min
- 35 to 56% FiO2
- With higher flow rates more loss of air through sides
- Humidification common
Trach mask
- similar specs to face mask( 5-10 L/min and 35-56% FiO2)
- ALWAYS HUMIDIFIED
Why must a trach mask be humidified?
Humidification of air happens in the upper airways the trach bypasses those airways
Venturi Mask
- Much more specific /precise FiO2 delivery
- Order for FiO2
- Dictates the Liters/min setting on the O2 supply
- Provides more support
- Used to ensure a specific saturation is achieved
Non-Rebreather Mask
- Can provide up to 100% O2
- Bags fills from wall with (O2>15 L/min)
- Breathe in air from bag
- Breathe out air goes into the room
- One way valve prevents air from mixing
- Due to a high flow rate you need to start with a full tank or bring a spare during ambulation
High Flow Nasal Cannula
25-60L/min
CPAP
(Positive airway pressure)
- Constant positive pressure during both inhalation and exhalation
- common in sleep apnea
BiPAP
- 2 levels of pressure; one for inhalation the second is for exhalation
- used to wean off of the ventilator
- ## use prior to invasive ventilator
Invasive Mechanical Ventilator
- Provides support for those with pending/existing respiratory failure or those in need of airway protection
Reasons for Mechanical Ventilation
1. failure to oxygenate = inadequate exchange of gas at the alveolar level
2. failure to ventilate = ppl with decreased mental status or if compliance of the lung decreased so much that the patient cannot ventilate on their own
3. Combination of both= difficulty oxygenating and ventilating
4. Airway protection= used in trauma when trying to protect the patients airways
What are the 2 types of Invasive Mechanical Ventilation?
- Endotracheal tube= short term
- Tracheostomy tube= longer term issues
What are the ventilator Settings
-Tidal Volume = amount of air delivered per breath
- PEEP Positive expiratory end pressure= pressure used to keep airways from collapsing
- Respiratory Rate= breaths per minute machine delivers
- FiO2= percent of O2 in air delivered
- Mode= amount of assist
what are the 4 Levels of Assist?
- Control Mode
- Assist Control Volume Control
- Synchronized Intermittent Mandatory Ventilation (SIMV-VC)
- Spontaneous or Pressure Support
Control Mode
(4 levels of Assist)
- ventilator has complete control
- volume and RR set no pt initiation
Assist Control- Volume Control
(4 levels of Assist)
- set number of breaths RR
- Every breath has set volume
- Pt can initiate more breaths- machine still gives the set volume
- patient has a little bit of involvement
Synchronized Intermittent Mandatory Ventilation (SIMV-VC)
(4 levels of Assist)
- set # of breaths with set volume given
- When pt takes more breaths than set RR
- Tidal volume is NOT controlled- pt can breath spontaneously without any set tidal volume
Spontaneous or Pressure Support
(4 levels of Assist)
- set pressure , PEEP and FiO2
- pt dictates tidal volume and RR
Media Sternotomy
- Initial skin incision usually begins inferior to the suprasternal notch and extends down midline of the sternum to below the xiphoid
- A sternal retractor divides the sternum fully and holds the incision open
Posterolateral Thoracotomy
- Approach used for : hemo or pneumo thorax pulmonary resections
- positive= it gives good visibility
- negative = pain, mobility and pulmonary issues
- Incision is from T4- level of medial scap around to the tip of the scap to anterior axilla at the 5th-6th intercostal space
- Muscle sparing has better functional results
Anterolateral Thoracotomy
- Incision from sternal edge to midaxillary
- At level of 4-5th intercostal space
Left Incision:
- cardiac tamponade
- descending thoracic aorta repair
- Pericardial effusion/left pneumonectomy
Right Incision
- right pneumonectomy
- distal esophageal surgeries
- Access to the hilum
- Mitral valve repair/replacement (minimal incision)
Axillary (Lateral Thoracotomy
- Most frequent use= minimally invasive cardiac procedures and epicardial pacemaker placement
- Shorter length incision (horizontally or vertically) to be muscle -sparing for chest and shoulder muscles
Disadvantages: - Least amount of visibility for surgeon
Advantages: - minimize change in pulmonary function and mobility greatly aids recovery
Subxiphoid Incision
- one incision
-Pericardium or epicardium procedures
Thoracoabdominal surgery
- Diaphragmatic Procedures
Minithoracotomy means=
- refers to shorter incisions used in surgical techniques
Advantages of VATS and RATS vs. Open Thoracotomy
- greater delicate handling and precision of instrumentation for surgeons
- reduced hospital length of stay
-Decreased blood loss - Lower inscisional pain
- Less negatively affected pulmonary functions
- Earlier patient mobility
- Decreased inflammatory cytokine reaction to surgery
Thoracic Surgical Complications
- Most often related to pain, blood loss, bleeding , medication effects and infection
Major causes of perioperative morbidity and mortality=
- respiratory complications; atelectasis, pneumothorax, pneumonia, respiratory failure
- prolonged air leaks
- Cardiac complications; arrythmias and ischemia
What are some early therapeutic interventions after a thoracotomy?
- splinting for pain
- splinted cough technique
- incentive spirometer use
- functional mobility to encourage chest expansion and airway clearance
- reducing the risk of atelectasis, pneumonia, and venous thromboembolism
What is the purpose of a chest tube?
remove air, fluids or blood from pleural space
- prevents air or fluid from reenetering pleural space
- reestablish intrapleural and intrapulmonary pressure after surgery or trauma
Chest tube is inserted into mediastinum to drain fluid from pericardial sac
Chest tube placement
- toward the top of the lungs in the plural space
- for fluid the tube is placed lower and is placed using imaging or CT to guide
IABP
(Intra Aortic Balloon Pump)
Assist with circulation of blood and reduces O2 consumption
- The balloon is inflated and diastole at rest and pushes the blood into the ventricle preloading it –> then when the heart contracts the balloon is deflates and less pressure/resistance to flow and also has a larger preload which will both increase the cardiac output and ejection fraction
PVAD
(Percutaneous Ventricular Assist Device )
- unloads the failing ventricle to improve systemic perfusion to other organs
- the difference this is an external device
- LVAD = left ventricular assist device could be implanted and both of these devices aid in restoring adequate cardiac output and helps the patient recover from Left ventricular failure or secondary organ dysfunction - these devices are temporary
Dialysis
What are the 2 types?
- Acute/Chronic kidney failure
- Filters fluid and electrolytes and corrects imbalances caused by kidney failure
2 Types:
1. Parataneal= put the fluid and chemicals to help filter the blood into you abdomen and then they get drained out
2. Hemodialysis= where they take the blood out process it and then put it back in
What do Arterial Blood Gases Tell us?
- Acid Base Balance
- Alveolar Ventilation
- Oxygenation
What are the normal values and ranges for
1. pH
2. Pco2
3. PO2
4. HCO3-
5. % SAT
- pH =Normal Value 7.40 : Normal range 7.35-7.45
- Pco2= Normal value 40 mmHg: Normal range 35-45mmHg
3.Po2= Normal Value 97 mmHg: Normal Range >80 mmHg
- HCO3-= Normal Value 24: Normal Range 22-28
- % SAT= Normal value 97%: Normal Range >95%
What does PaCO2 directly reflect?
It directly reflects the adequacy of alveolar ventilation
Values of Hyperventilation, hypoventilation, and ventilatory failure
- Hyperventilation= PaCO2 <40 mmHg
- Hypoventilation= PaCO2 >40 mmHg
- Ventilatory Failure = PaCO2 >50 mmHg
To determine the nature and severity of the illness with accuracy the relationship of arterial pH and arterial CO2 tension is assessed
How can Ventilatory failure be diagnosed?
It can only be diagnosed on the basis of partial pressure CO2 (Pco2) its severity is determined by the extent acidemia and rapid changes of pH
What does Acid Base Balance assess in the arterial gas analysis?
Assessment of blood pH- nature and magnitude of respiratory and metabolic disorders
- Lung and Kidneys regulate pH in the blood stream IT IS RESPONSIBLE FOR THE REGULATION OF BICARBONATE
- Bicarbonate is a major buffer of acids in the bloodstream and kidneys
What does low HCO3 lead to ?
Metabolic acidosis
High PaCO2 is
alveolar hypoventilation /hypercapnia(build up of CO2 in the bloodstream)
High HCO3 leads to ?
metabolic alkolosis
Low PaCO2 is
alveolar hyperventilation / hypocapnia (respiratory alkalosis)
What does Base Excess reflect?
BE reflects the concentration of bicarbonate in the body
- Normal PaCO2 = 80-100 mmHg
PaO2 <80 mmHg means?
Hypoxemia
pH for Acidosis
pH<7.40
pH for Alkalosis
pH >7.40
PaCO2 Acidosis what if it -
1. has decreased PaCO2
2. has Increased PaCO2
- Metabolic Acidosis
- Respiratory Acidosis
Arterial Blood Gas Analysis looks 1,2,3 thing you look at
- pH
- PaCO2
- Bicarbonate
- pH <7.40
- Decreased PaCO2
- Decreased HCO3-
This would mean
Metabolic Acidosis
- pH<7.40
- Increased PaCO2
- Increased HCO3-
Respiratory Acidosis
Respiratory Acidosis Causes=
Hypoventilation
- oversedation
- head trauma
- NM disorder
- Cardiac Arrest
- Chest trauma
- COPD
- Pneumonia
Symptoms of Respiratory Acidosis =
- tachycardia
- confusion
- Drowsiness
- dizziness
- Minimal if chronic COPD
Causes of Metabolic Alkalosis
- Loss of acid from GI tract or kidney
- vomiting
- laxative abuse - Increase HCO3- reabsorption or generation
- excessive use of antiacids
Symptoms of Metabolic Alkalosis
- Tetany
- Hypertonic muscles
- Numbness
- Asymptomatic
Metabolic Acidosis causes =
- Increased production of acids
- ketoacidosis
- Lactic acidosis - Decrease acid excretion by kidneys
- renal failure - Loss of alkali
- diarrhea
Symptoms of Metabolic Acidosis
- DOE
- Deep, rapid, breathing
- disorientation
- Fatigue
- weakness
Causes of Respiratory Alkalosis
- Hyperventilation
- anxiety/fear/pain
- excessive mechanical ventilation - Hypoxemia
- CHF
- PE
Symptoms of Respiratory Alkalosis
- Numbness and tingling of lips and extremities
- dizziness
- sinus arrythmia
- If the PaO2 is 40 what is the O2 saturation?
- PaO2 is 50 what is O2 saturation?
- PaCo2 is 60 what is O2 saturation?
- 70%
- 80%
- 90%
T/F pulse oximetry is an indirect measurement of O2 saturation
True
Mild Hypoxemia : PaO2 =
60-89 mmHg
Moderate Hypoxemia : PaO2 =
40-60 mmHg
Severe Hypoxia : PaO2=
<40 mmHg
How is the oxygenation status of a patient assessed
PaCO2 that is above or below normal range
What can Venous Blood gases provide the status of ?
pH and PaCO2
Chest Radiographs
- predominant diagnostic test to determine anatomic abnormalities and pathological processes within the chest
- Principle objects= air, fat, water, tissue, and bone
- Air is dark to bone which is white on radiograph
- Taken in two views PA and left lateral
How many ribs should be seen to be considered good for radiograph
at least 9 ribs
What should you be checking in a radiograph
- Check for optimal penetration of the film: branching of the small pulmonary vessels to the edges of the lung and rib outlines behind the heart shadow
- Check rotation: trachea should be midline and medial clavicles equidistant from midline
- A good inspiration will show at least 9 posterior ribs on the right side of the chest
- How big should the heart size be of the chest cavity?
- What should the great vessel aorta be just wider than ?
1.<50% of the width of chest cavity
2. T-spine
Lung Findings
1. Darker areas mean
2. Lighter areas mean
- Radiolucent, pneumothorax, bullae, air bronchograms
- Opacities, infiltrates (including blood, pus, water), nodules or mass
Advantages of a CT
- much more sensitive
- evaluates= heart, lungs, mediastinum, pleura, chest wall, upper abdomen ,
- Localize disease
- Guidance of interventional procedures
- Can detect occult pneumothorax or effusions
- Evaluates chest tube placement
- can contribute new information
- May detect unsuspected abnormalities
Disadvantages to a CT scan
- Risk of transporting patient out of intensive care unit enviornment
- significance increased radiation
- risks of intravenous contrast
MRI Magnetic Resonance Imaging
- Involves the interaction of stimulated hydrogen nuclei and strong magnetic field
- Primarily indicated for evaluation of chest wall processes
- May be indicated in individuals with abnormal chest radiograph that shows a nodule or mass
Bronchography
- Permits the study of abnormal and variant anatomy and gross pathological changes in the bronchial wall and lumen
What is the average Ventilation/Perfusion scan Ratio ?
- Why is one ordered?
Average value is 0.80
- Usually ordered when a pulmonary embolus is suspected
- requires radioactive isotopes ; technetium/Xeon
During a V/Q scan; nuclear test if there is a blood clot what ill it look like on the scan?
- There will be a blank space where the lung is not perfused it will be ventilated but it will not be perfused
What are the purposes of the Pulmonary Functional Tests
- Diagnosis of symptomatic diseases
- Screening for early, asymptomatic diseases
- Prognostic of known diseases
- Monitoring response to treatment
- As a diagnostic tool, PFT’s help classify diffuse lung diseases into categories
What are the 3 categories of PFTs
- Obstructive lung disease
- COPD
- Asthma
- Bronchiectasis
- Cystic Fibrosis - Restrictive Lung Disease
- Interstitial lung disease (pulmonary fibrosis, sarcoidosis)
-Chest wall pathology
- Obesity
- Neuromuscular disease (ALS, muscular dystrophy) - Pulmonary Vascular Disease
- Primary pulmonary hypertension
- Chronic thromboembolic disease
The 3 categories are not mutually exclusive
Bronchiectasis
an irreversible dilation and destruction of the bronchial tree, leading to chronic infections
What are the functions of the Pulmonary system that is tested by PFTs
- Airways
- Parenchyma (alveoli/interstitial)
- Pulmonary vasculature
- Bellows/pump mechanism (diaphragm/chest wall)- responsible for changes in the inter-thoracic pressure that cause air to move in and out of the lungs
- Neural control of ventilation
What are the the Standard PFTs
- Spirometry
- Lung volume
- Diffusing capacity of carbon monoxide
Specialized PFTs
- ABGs
- Exercise Oximetry
- 6 minute walk test
- Peak flow
- Max Inspiratory and Expiratory Pressures
DLCO
(Diffuse Capacity of CO2)
Largely a measure of the integrity of the alveolar capillary membrane
- In conjunction with other tests, is responsible for suggesting the possibility of PVD
Peak Flow measures=
Measures the max expiratory air flow that can be delivered in a single breathe
- Typically used to gauge the severity of an asthma exacerbation
Max Inspiratory/ Expiratory pressure provides =
Provides a rough estimate of diaphragmatic strength in neuromuscular disease including predicting risk of respiratory failure during exacerbations such as impeding myasthenic crisis
Tidal volume =
Volume of air exchange during each resting breath
Inspiratory reserve volume
Inhale as deeply as possible - the amount of volume the person has now inhaled above normal tidal volume
Expiratory Reserve Volume
Breathe out as completely as possible the additional volume exhaled beyond what is exhaled during normal breathing
Residual Volume =
When every last mL of air that can be squeezed out of the lungs has been the volume of air that is still left inside
What are the 3 most important values of a PFT to interpret
FVC
FEV1
Ratio of FEV1:FVC
FVC= forced vital capacity
FEV1= forced expiratory volume in 1 second
- the volume exhaled within the first 1 second is the FEV1 and the maximum exhaled volume, typically achieved by 6 seconds or so is the FVC
T/F the maximum slope of the FVC maneuver equal to the peak expiratory flowrate?
True
What is the flow volume loop?
A graph of airflow as a function of volume
- Max slope of the graph is peak expiratory flow rate which is the same flow at the maximum point on the graph on the right
- Volume present within the lungs at the transition from maximum inspiration to expiration is equal to total lung capacity
The dorsal fin looking graph
What are the major and minor values measured by spirometry
- Major
- FEV1
-FVC
-FEV1:FVC ratio
- Flow volume loop - Minor
- Peak expiratory flow rate PEFR
- FEF 25-75%
- Maximal voluntary ventilation MVV
- Response to Bronchodilators
Variable Intrathoracic obstruction
- During forced expiration, the intrapleural pressure is higher than intratracheal pressure so the intrathoracic upper airway collapses during that phase of respiration, limiting airflow
- Inspiration is normal
Fixed airway obstruction
- maximum air flow would be blunted during both expiration and inspiration
Staging of COPD based on FEV1
- Stage 1 FEV1>80%
- Stage 2 50<FEV1 <80%
- Stage 3 30%< FEV1 <50%
- Stage 4 FEV1<30%
WEAK CORRELATION BETWEEN FEV1 AND QUALITY OF LIFE
definition of DLCO
Is a measure of how much volume of CO2 diffuses per minute per unit of pressure across the alveolar capillary membrane
- A measured DLCO that is less than 40% predicted is considered severe impairment
- Any lung disease which either decreases functioning alveolar SA, or increase the thickness of the alveolar capillary membrane will lead to decreased DLCO
How should the DLCO be adjusted for
1. Anemia/Polycythemia
2. Abnormal Lung Volume
- DLCO should be adjusted downwards for Anemia and Upwards for Polycythemia
- Predicted DLCO is occasionally adjusted downwards for low lung volumes and upwards for high lung volumes
Primary Indications for Measuring DLCO
- To categorize a patient with restrictive lung disease as either probable ILD verses extrathoracic restriction
- To identify early IDL in high risk patients
- Quantify anatomic emphysema in patients with COPD
- TO document disability for legal purposes
Radiograph
ABCDEFG=
Assessment - image quality
Bones/Body wall
Cardiac Silhouette and size
Diaphragm
Equipment/Effusion
Fields - should look symmetric
Great vessels
