Exam 1 Flashcards
ventilatory status
See if they’re retaining or releasing carbon dioxide
BiPap to increase ventilation
If on ventilator, increase settings to have patient ventilate more
Contraindications of ABG
Bleeding disorder
AV fistula
Severe peripheral vascular disease, absence of an arterial pulse
Infection over site
Which artery to use for ABG
The radial artery is superficial, has collaterals, and is easily compressed. It should almost always be the first choice
Other arteries (axillary, femoral, dorsalis pedis, brachial) can be used in emergencies
what medicine is in ABG and what can it alter
heparin!
Preloaded dry heparin powder
Eliminates dilution problem
Mixing becomes more important
May alter sodium or potassium levels
air bubble in ABG
pO2 will begin to rise, pCO2 will fall
Oxygen is 21% of air
Oxygen concentration in blood is lower than air. Air goes from high concentration (bubble) to low concentration (blood), falsely elevating oxygen levels
CO2 concentration in blood is higher than air. CO2 goes from high concentration (blood) to low concentration (bubble), falsely decreasing CO2 levels
pH falsely elevated because of low CO2
Transporting ABG
After specimen is collected and air bubble is removed, gently mix and invert syringe
WBCs are active and will consume oxygen (PaO2 will decrease, PaCO2 will increase)
Get blood analyzed within 30 mins
Place ABG on ice to stop WBCs from being active
how to do ABG
Withdraw the needle and hold pressure on the site
Protect needle
Remove any air bubbles
Make sure blood is in contact with heparin
Gently mix the specimen by rolling it between your palms
Place specimen on ice and transport to the lab immediately
Pressure on the site and monitor for bleeding
Arterial vs venous pH
Arterial: 7.35-7.45
Venous: 7.32-7.42
Venous is lower because low O2 and high CO2
pH compatible with life
6.8-7.8
pH regulation methods
chemical buffer system
lungs
kidneys
why is bad pH harmful?
Bad pH denatures proteins
Chemical buffer system
Binds or releases H+
Intra and extracellular buffers
Three major chemical buffer systems
bicarb
phosphate
protein buffer systems
Extracellular buffer example equation
H2O+CO2=H2CO3=H+ +HCO3-
Intracellular buffers
Proteins, organic and inorganic phosphates, hemoglobin in RBC
Lungs in buffer system
regulates ventilation in response to CO2 in blood (CSF=central chemoreceptor)
Rise in partial pressure CO2 in arterial blood stimulates respiration, more powerful than the decrease of partial pressure of O2
How long do the lungs take to regulate pH
Takes minutes to activate, timing of peak compensation 1-24 hours
COPD and ventilation
Patients with COPD should NOT be over oxygenated because it will destimulate breathing
Kidneys in buffer system
Regulaes bicarb AND H+ by regenerating bicarb or absorbing them from renal tubular cells
How long do the kidneys take to regulate pH
hours to days (12h-5d)
Studies are done from healthy pts, no research from critically ill population
For which acid-base imbalance is the body’s compensatory system poorest
metabolic alkalosis
respiratory acidosis clinical manifestations
increased ICP (acute) due to: increased CO2 which leads to cerebrovascular dilation and increased cerebral blood flow
Papilledema and dilated conjunctival blood vessels
Hyperkalemia (H+ into cells means K+ comes out of cells and into blood)
Respiratory alkalosis manifestations
Lightheadedness from decreased cerebral blood flow
Inability to concentrate
Numbness and tingling (affect nerve function)
Dysrhythmias (hypokalemia)
metabolic acidosis due to loss of bicarb
hyperchloremic acidosis
diarrhea
lower intestinal fistula
Use of diuretics (carbonic anhydrase inhibitors such as acetazolamide, dorzolamide)
Early renal insufficiency
Excessive administration of chloride
Administration of parenteral nutrition without bicarb
metabolic acidosis due to excessive accumulation of acid
Lactic acidosis (anaerobic metabolism) (infection)
Late phase of salicylic poisoning
Kidney failure
Methanol or ethylene glycol toxicity (found in automotive antifreeze and de-icing solutions, windshield wiper fluid, solvents, cleaners, fuels, and other industrial products)
Ketoacidosis (diabetes)
Starvation
Clinical manifestations of metabolic acidosis
HA, confusion, drowsiness
Increased respiratory rate and depth
Nausea and vomiting
Peripheral vasodilation and decreased cardiac output (when pH<7)
Decreased blood pressure
Cold and clammy skin
Dysrhythmias
Shock
Metabolic alkalosis due to loss of H+
Vomiting or gastric suction most common
Hypokalemia (kidneys hold on to potassium by excreting H+, K+ moves out of cells and H+ moves in)
Too much bicarb (antacids or sodium bicarb during CPR)
Manifestations of metabolic alkalosis
Muscle twitching: affect neuromuscular function
Hypokalemia: arrhythmia
what kind of air do trach patients get
warmed and humidified
Risk for infection since nose filters the air and they can’t do that
What allows us to inhale
Pressure difference!
Chest cavity pressure has to be lower than outside air pressure
This happens when chest cavity expands
Inhalation
Muscles contract, diaphragm contracts (moves down), space increases
Inhalation takes effort and is shorter
Exhalation
Longer, passive movement
relaxing, everything is relaxed, space gets smaller, pressure is increased, air gets pushed out
anatomy of bronchi
Right bronchus is straight, making it more likely to choke in right lung than left
If ET tube goes too far, it can end up in the right lung and won’t help the left lung
Quick assessment, listen to lungs to make sure they’re both being ventilated
2 phases of respiration
Gas exchange between the atmosphere and the body
Gas exchange within the cells (air and blood, and blood and cells)
what drives respiration
Levels of carbon dioxide in the arteries
Very little by oxygen level: account for 10% of the total drive
COPD patient (relies on oxygen, big CO2 buildip)
Perfusion
the circulation of the blood that must be able to transport oxygen to the tissues and cells
Good ventilation and bad perfusion
heart failure, anemia, blood clots, sickle cell
Lung compliance
Lung compliance=elasticity=ability of lungs to go back to regular shape
Low lung compliance
stiff balloon, easy to get CO2 out, hard to get O2 in. Decreased ventilation. Examples are pleural effusion, obese, pulmonary fibrosis, scoliosis, etc., lung can’t expand
High lung compliance
Floppy balloon, easy to get O2 in, hard to push CO2 out. CO2 retention decreases drive to ventilate
COPD or emphysema, reduced ventilation due to decreased ventilatory drive
Alveoli inflated all the time
Can cause barotrauma
V/Q ratio
HAS TO MATCH
V=ventilation, Q=perfusion
Low V/Q
shunt perfusion–alveoli perfused but not ventilated (ET tube in mainstream bronchus (not in place, air doesn’t get to lungs), obstruction, collapsed lung
Normal V/Q
~0.8: alveoli perfused and ventilated
High V/Q
dead space ventilation–alveoli ventilated but not perfused (cardiac arrest, anemia, clots)
Poorly ventilated alveoli –> decreased ventilation –> shunt
Silent unit
In the absence of both ventilation and perfusion or with limited ventilation and perfusion
Pneumothorax (Less blood going back to the heart leading to less CO and less perfusion)
severe acute respiratory distress syndrome (Inflammation and vasoconstriction cause impaired blood distribution and less perfusion)
(Some condition that also reduce the blood flow…shocks)
V/Q at top/apex of lungs
V/Q: 3.3, PaO2: 132, PaCO2: 28
V/Q at middle of lungs
V/Q: 1.0, PaO2: 108, PaCO2: 39
V/Q at bottom of lungs
V/Q: 0.63, PaO2: 89, PaCO2: 42
functions of a chest tube
To remove air or fluid from chest
Chest tube to remove fluid is thicker than that for air
Air trapped=pneumothorax. Chest tube gets placed anterior to remove air. Posterior to remove blood (hemothorax)
Equation for oxygen delivery to tissues
Delivery=cardiac output (like perfusion) x O2 content of blood (like ventilation)
What 3 things determine oxygen in blood
O2 binding company
% saturation
Dissolved O2
O2 binding capacity
How much oxygen the blood can hold
Determined by hgb (anemics don’t have enough, although hemoglobin is well occupied by oxygen, there isn’t enough actual hemoglobin)
% saturation
% hemoglobin molecules saturated
Measured by pulse ox
Uses light and photodetector
Can’t distinguish between hgb bound to O2 and CO, so patients with CO poisoning can have an O2 sat of 100
Anmics can also have an O2 sat of 100% but have poor oxygen delivery to tissues (hypoxia without hypoxemia)
Dissolved O2
O2 directly dissolved in blood (water)-(can be used by fish, not us). Very small amount (negligible)
PaO2
partial pressure of oxygen in arteries
Higher PaO2 means more oxygen dissolved in plasma
SaO2
% oxygen saturation of blood in arteries (% of hgb carrying oxgyen
PO2
Partial pressure of oxygen in air
Air pressure at sea level: 760 mmHg
PO2 at sea level: 760x21%=160 mmHg
Air pressure at 5000 feet: 633 mmHg
PO2 at 5000 feet: 633x21%=133 mmHg
PO2 at sea level and 5000ft
PaO2 at sea level: 100 mmHg
PaO2 at an altitude of 5000 feet: 70 mmHg
Low pressure=more difficult for hemoglobin to bind (likely to have enough oxygen in blood though)
This is why it’s hard to breathe when mountain climbing
Low flow oxygen
Low CONSISTENCY
patient breathes some room air along with the oxygen
Not constant and precise concentration of inspired oxygen
Example is nasal cannula
High flow oxygen
High CONSISTENCY
Constant and precise concentration of oxygen
Example is ventura mask
hypoxemia
below normal levels of oxygen in the blood (not as important)
Hypoxia
decrease in oxygen supply to the tissues and cells (can happen even when there’s enough oxygen in the blood)
hypoxemic hypoxia causes
Hypoventilation, high altitude, ventilation perfusion mismatch, shunts…
circulatory hypoxia
Decreased cardiac output, local vascular obstruction (normal PaO2, but tissue partial pressure is reduced)
Anemic hypoxia
CO poisoning (decrease in oxygen carrying capacity)
Histotoxic hypoxia
cyanide, toxic substance prevents the tissue to utilize oxygen
Nasal cannula FiO2
1 liter: 24% (21% from atmosphere)
2 liters: 28%
3 liters: 32%
4 liters: 36%
5 liters: 40%
6 liters: 44%
If patient is on ventilator, we use FiO2 instead of liters
Nonrebreather
Nonrebreathing masks have three one-way valves. Theoretically, it is possible for the patient to receive 100% oxygen. (Depends on the fit of the mask) This mask ensures the most oxygen possible (highest concentration) and is most effective besides intubation
Nonrebreather has 3 one way valves so patient can breathe out but not breathe atmosphere air back in
FiO2 82-100%
Partial rebreather
Allows a small amount of atmosphere air to be breathed
Oxygenation for COPD
Use bipap
thoracentesis
At the bedside
Sterile environment
Fluid gets sent to the lab to test
Fluid in pleural space (can’t go in each space, it’s impossible)
Air in x-ray is black, fluid is white and fluffy in the tissues as well
Crouch forward on pillow for easy access and so everything opens up
X-ray and auscultation for dull sounds to find fluid and know where to put needle
bronchoscopy
used to see what’s going on (blockage, inflammation, fluid)
X-ray to find nodules, then CT/MRI, then bronchoscopy and collecting sample
Can remove foreign objects or something blocking the airway
Gag reflex needs to be removed before bronchoscopy, need to monitor gag reflex after and keep them NPO
3 bottle system
not very advanced
Does the same stuff as drainage systems
1 bottle used when we need to get air out submerged in 2cm of water to prevent air from going back in
wet vs dry drainage system
Wet and dry do the same thing, wet one always needs fluid to maintain suction, dry doesn’t so it’s better. Dry one is also quieter
For both, check consistency and color of drainage
Water seal chamber
Has 2cm of fluid
fluctuations correspond to intrathoracic pressure during respiration
Consistent water levels mean lungs are fully expanded, tubing is blocked or disconnected, or the water seal level is incorrect
Continuous bubbling means air leak
Gentle bubbling during expiration is expected in patients with pneumothorax
Suction chamber
Slow and steady (or continuous) bubbling is expected when suction is applied
Should be 20 cm of fluid
Continuous suction: pneumothorax
Intermittent suction: fluid drainage
Should you clamp a chest tube?
ONLY UNDER CLOSE MONITORING! Very quickly to check for an air leak or change the tubing
Tube dislodged from patient’s side
Ask the patient to cough and exhale to prevent air back into the body
Cover the site with a sterile occlusive dressing to prevent air from entering the pleural space
3 sides of tape on dressing allows 1 way valve (air goes out not in)
Tube dislodged from drainage system side
Immerse the end of the tube into a bottle of sterile water (tip of the tube is about 2 cm below the water level)
chest tube insertion
slight subq emphysema might be present but should not spread. Mark it so you can monitor for spread
Chest tube removal
Ask patient to take a deep breath, hold it and bear down while the tube is removed
Milking the chest tube
NEVER
Chromosome
Microscopic structures in the cell nucleus that contain genetic information
Genome
Total genetic compliment of an individal genotype
Gene
A unit of heredity
Hypercholesteremia genotype
Mutations in low-density lipoprotein (LDL) receptors
mutations in one of the apolipoprotein genes
Phenotype of hypercholesteremia
Early onset of CVD
High level of LDL
skin xanthomas
family history of heart disease
Gene mutation
Inherited or spontaneous
Inherited: Huntington’s disease. Occurs in the DNA of all body cells
Spontaneous: achondroplasia, marfan syndrome, and neurofibromatosis type 1
Genetic testing vs genetic screening
testing: more targeted and individualized approach used to investigate known or suspected genetic disorders
Screening: a broader, systematic process applied to populations or specific groups to identify individuals at risk of genetic conditions, often in the absence of clinical systems
Family history consists of
family history 3 generations (parents, siblings, and children)
Personal and medical risk factors
Identification of associated diseases or clinical manifestations
Pulmonary edema
Abnormal accumulation of fluid in the lung tissue, the alveolar space, or both
White fluffy in x-ray
BILATERAL!!
Why is pulmonary edema so bad
Fluid in alveoli means no room for gas exchange
hypoxic, hypoxemic