Respiratory Wk 6 NRS 222 (pH/acid-base) Flashcards
What ion must be kept within a narrow range within body fluids to maintain homeostasis?
What does the balance of hydrogen ions in the body determine?
Why does hydrogen determine relative acidity?
Acids release hydrogen, and bases accept them
What is another word for a "Base"?
As hydrogen ion concentration rises, pH ________
The relationship between pH and hydrogen concentration is __________
As hydrogen concentration falls, pH ___________
What pH balance is neutral?
Healthy human pH is between what?
What pH can result in death?
What is a volatile acid?
An acid that can be eliminated from the body as a gas
What is the ONLY volatile acid in the body
carbonic acid (H2CO3)
What is carbonic acid made from?
water and carbon dioxide
After carbonic acid dissociates, how is it expelled?
as carbon dioxide and water in the lungs
All acids in the body aside from carbonic acid are:
How must nonvolatile acids be excreted?
they must be metabolized or excreted in fluid
What is metabolized down to phosphoric acid?
phospholipids & phosphoproteins
What is metabolized down to lactic acid?
dead ass cells
What is metabolized through oxidation down to sulfuric acid?
sulfur containing amino acids
What does it mean for acids and bases in the body to be weak?
they neither release or retain very many H+ ions
Are most bases in the body weak or strong?
What are the three systems that regulate pH in the body?
THE BUFFER SYSTEM
What are buffers?
substances that pick up hydrogen ions to prevent major acidotic changes
What are the three subsystems of the buffer system?
In plain words, how do buffers work?
They either release or bind to hydrogen to prevent major pH changes
What is a normal serum bicarb level?
What is a normal serum carbonic acid level?
What is the normal bicarb-carbonic acid ratio?
What is more important, the bicarb-carbonic acid ratio, or their specific serum levels?
When the bicarb-carbonic acid ratio is appropriate, what is the body's pH expected to be?
Is bicarb a strong base?
Is carbonic acid a weak acid?
How does the respiratory system maintain the body's pH?
By retaining or releasing carbon dioxide, which can be combined with water to form carbonic acid
How does the brain respond acute increases in carbon dioxide or hydrogen?
the respiratory center causes the body to take deeper, more frequent breaths in order to "blow it off"
When the body is in alkalosis, how does the body use its respiratory center to correct this?
depressing rate a depth of breathing to retain co2
What type of pH regulation is the renal system responsible for?
what do the kidneys excrete to avoid acidosis?
What produces the nonvolatile acids that the kidneys filter and excrete?
The body's metabolism
Which organ system does all the bicarb stuff?
The kidneys excrete or hold onto which ions in response to pH changes?
What do the kidneys produce to buffer an excess of acids in the body?
In alkalosis, the kidneys excrete _________ and retain _________
In acidosis, the kidneys excrete _________ and retain _________
WHat is the body's pH when there is an above normal hydrogen concentration?
WHat is the body's pH when there is a below normal hydrogen concentration?
In METABOLIC acidosis or alkalosis, what is the primary change?
What can cause metabolic acidosis?
excessive nonvolatile acids
What labs represent metabolic acidosis?
Bicarb under 24 mEq/L
What labs represent metabolic alkalosis?
Bicarb >28 mEq/L
In RESPIRATORY acidosis or alkalosis, what is the primary change?
carbonic acid concentration
What occurs when carbon dioxide is retained by the body?
the increasing carbonic acid results in respiratory acidosis
What PaCO2 signifies respiratory acidosis?
What is PaCO2?
the pressure exerted by dissolved carbon dioxide in the blood
What PaCO2 signifies respiratory alkalosis?
What can cause a loss of excessive amounts of carbon dioxide?
Why does hyperventilation cause respiratory alkalosis?
The body does not have time to absorb appropriate amounts of CO2
What is a PRIMARY acid-base disorder?
A disorder with one cause
(ie respiratory failure)
What is a MIXED acid-base disorder?
occurring due to mixed metabolic & respiratory issues
(ie cardiac arrest)
In primary metabolic acid-base disorders, which subsystem compensates?
the pH change effects the rate and depth of breathing
In primary respiratory acid-base disorders, which subsystem compensates?
the pH change triggers the kidneys to adjust bicarb conservation and hydrogen elimination
How quickly does respiratory compensation take effect?
What is the downside to respiratory compensation?
it becomes less effective as time goes on
the renal system takes longer to compensate for respiratory acid-base disorders. What is the upside?
it is longer lasting
When the ABG reflects acid base alterations, but pH is restored to normal it is considered__________
If ABG reflects compensation for acid base issues, but the pH is still all fucked, it is considered __________
What typically causes acid-base issues?
Critical illnesses of many kinds
How can acid-base issues lead to cardiac arrest?
by decreasing tissue perfusion
What is the main focus in preventing acid-base issues?
Proper hydration--fluid balance
What should patients be assessed for to determine general risk for acid base disturbance?
-anything that can cause a net gain/loss of acids and bases
What is a very common outward sign of acid-base disturbance?
Ultimately, what is metabolic acidosis?
Ultimately, what is metabolic alkalosis?
S & S for metabolic acidosis?
S & S for metabolic alkalosis?
S & S for acute respiratory acidosis?
irritability- altered mental status
S & S for chronic respiratory acidosis?
S & S for respiratory alkalosis?
If it is metabolic, which lab ranges are pertinent?
If it is respiratory, which lab ranges are pertinent?
What is a normal PaCO2 reading?
What is an acceptable PaO2 reading when there is concern for acid-base imbalance?
(However, less than 80 is considered hypoxemia)
What percentage of blood is transported in solution, and is available for cell use because it is dissolved?
What is an acceptable HCO3 reading when there is concern for acid-base imbalance?
Peripheral O2 sat of 90% should correlate to what PaO2 reading?
What is the gold standard for determining blood oxygen concentration?
(pulse ox can be affected by disease causing garbage peripheral perfusion)
Due to the fluid balance component of acid-base issues, what should a nurse do with the pt?
-assess renal function
Due to the oxygenation component of acid-base issues, what should a nurse do with the pt?
-assess neurological function and LOC
-assess respiratory function
-maintain patent airway
What is the ultimate result of severe, untreated metabolic acidosis?
What is the main concern with using sodium bicarb to treat acidosis?
overcorrecting-- it works fast
What symptoms must be watched for in administration of sodium bicarb?
irritability & confusion
What symptoms should be seen in a pt who is about to recieve sodium bicarb?
When can sodium bicarb be used?
ONLY if pH is under 7.2
Why should sodium bicarb be avoided if possible in the presence of cardiac and renal disease?
all dat sodium
Sodium bicarb can speed up the excretion of acids and alkalinize the urine. Which medication toxicities and side effects can be treated this way?
-certain chemos (methotrexate) --side effects
What is ion trapping?
when bicarb is used to trick the kidneys into not resorbing acids because the urine registers as alkaline
Because sodium bicarb is literally baking soda, what do cardiac pts accidentally do to themselves?
take an ass ton of it to treat "heartburn" that is really a cardiac emergency
--then they get the double whammy of cardiac emergency+systemic alkalosis
When is intubation typically indicated for a pt in respiratory distress?
-PaCO2 >77 mmHG
-PaO2 <60 mmHG
What can correcting CHRONIC hypercapnia (ie COPD) do to a pt?
metabolic alkalosis due to sudden retention of an assload of bicarb
What acid-base problem can hypernatremia cause?
What does lactic acidosis come from?
tissue hypoxia--> anaerobic metabolism --> lactate/hydrogen ions produced --> lactic acid formed
What causes ketoacidosis?
starvation/lack of insulin forces body to use fats---> fatty acid breakdown produces ketones
Why does lack of insulin have the same effect as starvation?
Water everywhere but not a drop to drink
(glucose cannot be moved into the cells)
What are some ingestible substances that break down and raise the body's acidity or stimulate production of metabolic acids?
aspirin/salicylates (salicylic acid)
What is high anion gap acidosis?
buffering of excess acids by bicarb
Loss of stomach acid causes alkalosis for obvious reasons, loss of what digestive fluids can cause acidosis?
bicarb rich pancreatic secretions
(Loss of GI fluid below the level of the duodenum )
What can cause acidosis from the loss of the bicarb in pancreatic fluid?
When does the anion gap remain normal in the presence of metabolic acidosis?
loss of bicarb
OD of sodium
Why does acidosis affect neuromuscular function?
it wrecks cell membrane excitability
increases calcium by fucking up protein binding
What does wrecked cell permeability and increased calcium result in when pH gets down to 7?
Garbage myocardial contractility--decreased CO
In normal kidney function, what is done to deal with decreased cell membrane excitability and excess calcium in metabolic acidosis?
increased production of ammonia
flushing out acids/H+
Why is hyperkalemia common in acidosis?
Hydrogen enters cells, displacing potassium because of natural maintenance of the balance of cations and anions
How does metabolic acidosis induced protein binding fuckery result in increased free serum calcium?
Calcium is released from plasma proteins
Which electrolyte may be decreased in metabolic acidosis?
What diseases are risk factors for metabolic acidosis?
anorexia (w/ cachexia)
laxative abuse/severe diarrhea
What are the GENERAL manifestations of metabolic acidosis?
What are the GASTROINTESTINAL manifestations of metabolic acidosis?
What are the NEUROLOGICAL manifestations of metabolic acidosis?
What are the potential CARDIAC and RESPIRATORY manifestations of metabolic acidosis?
Why might certain skeletal problems result in chronic acidosis?
phosphate and calcium are released from the bones
What are kussmaul respirations evidence of compensation for?
What is the primary focus in treating metabolic acidosis?
treating the disorder that led to it
What are the two biggest concerns when treating a metabolic acidosis pt?
reducing cardiac damage
Which electrolyte imbalance resulting from metabolic acidosis is the greatest concern?
How is metabolic acidosis difinitively diagnosed?
(+ tests indicated by causative disorder)
What can be given to a metabolic acidosis pt other than bicarb to alkalize?
(ie what metabolizes down to bicarb?)
In acute metabolic acidosis, bicarb/acetate/lactate/citrate is given IV. How is it given in chronic cases?
Why might bicarb use in treating acidosis lead to cardiac dysrhythmias if not carefully monitored?
K shifts back into cells at too fast a rate
When is bicarb not used to treat metabolic acidosis?
when the underlying condition can be treated instead
(crush injuries--perfusion enhancement)
What is the most common cause of metabolic acidosis in babies?
Why do older adults have an increased risk of metabolic acidosis?
-more chronic disease (DM, renal, metabolic)
-Polypharmacy (aspirin, diuretics, ACE inhibitors, etc)
Patients with underlying disease that puts them at risk of metabolic acidosis should be taught what?
metabolic acidosis presents with vague symptoms, like a virus, and they need to be seen if they develop them
In the patient with metabolic acidosis, what should slow cap refill and/or diminished peripheral pulse strength cause concern for?
In the patient with metabolic acidosis, what should widened QRS complex cause concern for?
potential cardiac arrest
increasing risk of dysrhythmias
Why can diminished cardiac output intensify the degree of a pt's metabolic acidosis?
decreased tissue perfusion leading to lactic acidosis
What can administration of sodium bicarb cause in relation to fluid balance?
Decreasing LOC should make one expect a decreasing _________ as well, in acid-base issues
In metabolic alkalosis, what do the lungs do to compensate?
slow respirations in an attempt to hold onto CO2, which can be combined with water to make carbonic acid
When metabolic alkalosis occurs due to a loss of hydrogen, what is typically the cause?
vomiting or gastric suction-- loss of highly acidic gastric secretions (pH 1-3)
Why is bicarb paradoxically retained in metabolic alkalosis resulting from a loss of gastric secretions?
Large amounts of chloride are lost, which are an important component in the cation-anion balance in extracellular fluid. Bicarb can be used to replace chloride's spot as an anion in this situation.
Why can hypokalemia cause metabolic alkalosis?
-as the kidneys try to conserve potassium, hydrogen may be lost instead.
-lack of potassium ions in cells may result in hydrogen ions shifting into them instead
In cases of metabolic alkalosis that are NOT due to acid loss, what has typically occurred?
excessive ingestion of bicarb through things like antacids
In acidosis, protein binding is reduced, causing hypercalcemia. What happens to calcium in alkalosis?
Binding is enhanced, potentially leading to HYPOcalcemia
What is the cause of most symptoms of metabolic alkalosis?
Decreased calcium ionization
Hypokalemia can cause metabolic acidosis, but it can also BE caused by metabolic acidosis. How?
Hydrogen ions shift out of cells in an attempt to restore pH, and potassium replaces them, removing them from the extracellular space
High pH _______________ the respiratory system
What are causes of PRIMARY metabolic alkalosis?
lactate administered during dialysis
ingestion of antacids
too much bicarb
What are SECONDARY causes of metabolic alkalosis?
NG suctioning/excessive vomiting
What age group is at the greatest risk of metabolic alkalosis and why?
older adults because of their fragile fluid balance
What happens if a chronic hypercapnia pt (ie COPD) pt's PaCO2 levels are reduced too quickly?
Since outward s&s of metabolic alkalosis results from decreased calcium ionization, and present like hypocalcemia, what might be present in an alkalosis pt?
-numbness/tingling around mouth, fingers, toes
What is trousseau sign?
-spasm of hand and fingers due to occlusion of blood supply
What does respiratory compensation for metabolic acidosis ultimately lead to over time?
Which electrolyte imbalance EKG pattern might be seen in the metabolic alkalosis?
that of hypokalemia
What does pharmacological treatment of moderate metabolic alkalosis entail?
potassium chloride and sodium chloride
How do chloride solutions help correct metabolic acidosis?
chloride encourages excretion of bicarb
What does pharmacological treatment of severe metabolic alkalosis entail?
dilute hydrochloric acid or ammonium chloride
What are the most likely causes of metabolic alkalosis in children?
How can a nurse help treat the respiratory issues that come alongside metabolic alkalosis?
-positioning that facilitates respiration--prevents aspiration
-assessment of RR and depth
Why is vomiting more likely to cause metabolic alkalosis in older adults than younger adults?
Diminished sense of thirst--> may already be dehydrated or borderline
When can dehydration cause alkalosis?
When hypokalemia is present
Aside from whatever the underlying cause is, what is a priority problem with metabolic alkalosis?
impaired gas exchange
(due to respiratory compensation)
When should O2 sat on a metabolic alkalosis pt be reported, unless otherwise specified?
What bicarb level is found in respiratory acidosis?
What potentially fatal phenomenon often follows respiratory acidosis?
What typically causes ACUTE respiratory acidosis?
** anything that fucks up o2-co2 exchange severely enough**
Why does PaCO2 rise and pH fall so quickly in acute respiratory acidosis?
the causative factor causes rapid onset hypoventilation
Why is there no evidence of renal compensation during most acute cases of respiratory acidosis?
they are either short lived or result in death, and the kidneys take hours or days to compensate
What might one find in an integumentary assessment of a pt with metabolic acidosis?
warm, flushed skin
What sudden failure does acute respiratory acidosis result from?
failure of ventilation
exchange of o2 and co2
Where do the vision problems associated with respiratory acidosis come from?
Intercranial pressure eventually inflames the optic nerve
Cerebral vasodilation due to respiratory acidosis leads to headaches and visual problems, what does it do peripherally?
lowers BP, triggering the heart to increase pulse rate
What is chronic respiratory acidosis associated with?
-Chronic respiratory and neuromuscular disorders that impact o2-co2 exchange severely enough
MS, CF, COPD etc etc
Why does pH remain relatively normal in cases of chronic respiratory acidosis?
the kidneys compensate by consistently resorbing lotsa bicarb
What happens to the respiratory center chemoreceptors when co2 is chronically high?
becomes less sensitive to gas as a stimulant of increased respiratory drive
What is carbon dioxide narcosis?
when chemoreceptors in the brain become less sensitive to Co2 due to chronic acidosis, too much supplemental oxygen suppresses the respiratory drive
--they breathe in response to minor hypoxia, and become dependent on it
For chronic respiratory acidosis pts, what PaO2 can trigger carbon diocide narcosis?
70mmHG or higher
What are the common clinical manifestations of hypercapnia induced vasodilation?
What is the ultimate outcome of untreated respiratory acidosis?
progressive decrease in LOC
potential lethal dysrhythmia
What method of breathing may help a chronic respiratory acidosis pt?
semi-fowler or fowler positioning
How can respirations in respiratory acidosis be assisted mechanically?
How might chronic respiratory acidosis impact electrolyte balance?
Respiratory alkalosis is ALWAYS caused by
What is the most common cause of respiratory alkalosis?
Other than anxiety, what are common causes of respiratory alkalosis?
**anything that causes hyperventilation**
Why is respiratory alkalosis common in pregnancy?
progesterone stimulates the respiratory center, leading to hyperventilation
Why might respiratory alkalosis occur during surgery?
mechanical ventilation during anesthesia is overdone
In chronic respiratory alkalosis, bicarb level is often __________
decreased due to long term renal compensation
Like metabolic alkalosis, respiratory alkalosis encourages the binding of calcium to proteins (albumin), and this process causes a reduction in
Like metabolic alkalosis, respiratory alkalosis causes symptoms of hypo-
The lack of cO2 present in respiratory alkalosis leads to ____________
vasoconstriction, causing neurological symptoms
Symptoms of respiratory alkalosis include:
seizures and loss of consciousness
Why is the paper bag method no longer used to treat hyperventilation/respiratory alkalosis?
increased co2 can increase anxiety
may cause hypoxia
What can a nurse do to help treat anxiety induced hyperventilation/respiratory alkalosis?
Coach slow, regular breaths into cupped hands
Which symptom of respiratory alkalosis is often particularly concerning to children and parents?
What symptoms are especially common in older adults with respiratory alkalosis?
What is often the best treatment fo respiratory alkalosis?
--manipulation of the environment
Respiratory alkalosis induced chest tightness, palpitations, pain and dyspnea often cause anxiety because the patient fears what?
having a heart attack
What is congenital acquired renal tubular acidosis?
A condition in which the kidneys excrete too much bicarb, and sometimes potassium
Where do circumoral paresthesias, as seen in respiratory alkalosis, occur?
around the mouth
How can the discomfort of paresthesias be treated in infants?
-calm quiet voice
How can the discomfort of paresthesias be treated in preschoolers?
How can the discomfort of paresthesias be treated in school aged children?
-reading familiar book
How can the discomfort of paresthesias be treated in older children and adolescents?
-music and videos