NURS 4581 Final Exam Study Success Notes
Acid Base Balance
Normal pH 7.35-7.45
The normal pH is maintained by the buffer system- respiratory and renal system
- Work together but at different speeds
Bicarbonate and carbonic acid buffer
- Stong acid converted into weak acid - resp. Or renal system can get rid of the weak
acids
Lungs
- Help maintain normal pH by excreting CO2 and water
- With sudden changes in blood pH, the resp system reacts within minutes and reaches
maximum effectiveness in hours
- Increased resp rate and depth= more CO2 expelled
- Decreased resp rate and depth= more CO2 remains in the blood- less expelled
Kidneys
- Maintain normal pH by reabsorbing or excreting bicarbonate and eliminating hydrogen
ions
- acidosis - generate additional bicarbonate and increase the amount of hydrogen ion
elimination
- Take 2-3 days to respond maximally to sudden changes in pH
PaO2- partial pressure of oxygen in the artery- oxygen that is dissolved in the blood
- P=partial bc there are other gases that are dissolved in the blood
- 80-100 mmhg
SaO2= oxygen saturation of aterial blood
- 90% or above
SpO2= oxygen saturation from pulse oximetry - noninvasive
Normal CO2=35-45
Normal HCO3= 22-28
ROME- Respiratory Opposite- Metabolic Equal
- Metabolic- pH value is equal to HCO3- both high or both low or both normal
- Respiratory- pH is low, CO2 high or vice versa
- If oxygenation is low- label with hypoxemia
Anytime pH is abnormal- uncompensated
Anytime pH is normal with other problems- compensated
Causes of Respiratory Acidosis
- Retention of CO2= not breathing -> caused by altered LOC, plastic bag over their head,
or resp failure
- S/S: shallow, weak ineffective breaths (guppy breathing) or no respirations,
disorientation, dyspnea, cyanosis or pallor
- Compensation is by the kidneys= hold onto HCO3, make more HCO3 or get rid of H+-
takes days to occur- nurse must intervene
- O2 controlled by resp rate-
®™ NURS 4581 Final Exam Study Success Notes
, NURS 4581 Final Exam Study Success Notes
- With compensated Resp. acidosis- pH will be normal, CO2 high and HCO3 high- HCO3
will be high because it is compensating for the acidosis- if it was a metabolic problem,
then the pH will be high
- Seen with chronic COPD patients- these patients have problems with exhalation
and frequently retains CO2 - kidneys have time to compensate- allowing for
normal pH
Causes of Metabolic Acidosis
- Too much acid production= ketoacids (DKA), poison ingestion, renal failure, diarrhea,
tissue hypoxia/lactic acid production
- S/S: Varied-DKA=acetone breath. Renal failure= edema. Kussmaul Respirations
- Respiratory compensation- remove acids/CO2. Resp. rate will be rapid and deep=
Kussmaul resp.
If patient is acidotic and HYPOkalemic- be cautious before correcting/treating acidosis
Causes of uncompensated respiratory and metabolic acidosis
- Too much acid production= DKA, poison, renal failure, diarrhea, tissue hypoxia, AND
resp. Failure (inability of the patient to remove CO2 and bring in O2)--- both systems are
broken
- S/S: varied or none at all
- Compensation: The renal and respiratory system are broken-> the pt is without the
ability to compensate and is most likely critically ill-> requiring mechanical ventilation
perhaps dialysis
Respiratory Failure, Mechanical Vent and Airway Management
Manifestations of Resp. Failure
- Use of accessory muscles, wheezing, rapid resp. rate, elevated HR/BP=SNS
stimulation
- If cyanosis were present=late sign
- Resp. failure is present when retained CO2 causes resp. acidosis and there is
hypoxemia
Treatment:
- Apply supplemental oxygen- humidified O2 can help liquefy secretions and reduce
drying of mucous membranes- if hypoxemia must give O2-lowest amount for least
amount of time- breathing treatment, elevate HOB, turn cough and deep breath if a post
surgical patient, steroid, assess hbg level
- Another option= CPAP-continuous positive airway pressure
CPAP
- The machine exerts positive pressure throughout respiratory cycle to help keep the
alveoli open (doesnt allow airway/alveoli to collapse)
- Delivered non invasively- may prevent intubation
- Keeping the alveoli open allows for a longer time for gas exchange
- Increases WOB- pt must exhale forcible against CPAP- use cautiously with pts with
myocardial conditions bc if we increase their WOB they can have an MI
Intubation
®™ NURS 4581 Final Exam Study Success Notes
, NURS 4581 Final Exam Study Success Notes
- Ensure oxygenation with bag valve mask before and after intubation
- After HCP inserts the ETT (endotracheal tube), prior to inflating the balloon of the ETT,
auscultate lung bases for bilateral breath sounds and look for chest rise/fall when giving
breaths with ambu bag
- If breath sounds are not heard- remove the tube bc pt is not getting O2
- Deliver O2 with BVM before HCP attempts to re-intubate
- Once bilat breath sounds are heard, inflate cuff/balloon of ETT to 20 mmhg (+/- 5 mmhg)
- Note measurement at lips and obtain chest x-ray confirmation of placement
- ETT will prevent the epiglottis form closing- the pt cannot swallow their saliva/oral
secretions
- ET balloon or cuff while inflated does not prevent the removal of the ETT
- Pt cannot speak when cuff is inflated
- Although the ET balloon is inflated, oral and gastric secreations can leak into the lungs
around balloon
Mechanical Ventilation
- Process where air (gas) is moved into and out of the lungs by a mechanical ventilator
- This is just a means of support to the pt
- Goals of ventilation are:
- Delivery of adequate oxygen
- Removal of CO2
- Reduce dyspnea
- Promote rest and reconditioning of fatigued respiratory muscles
- Once ventilator is initiated and the goals achieved AEB normal ABGs then the pt should
be weaned off the ventilator
Ventilator Settings
- Positive Pressure
- “Shoving” in air at the convenience of the ventilator
- May cause decrease in venous return- decrease CO- decrease BP- cause RAAS
activation
- Mode: How the pt and ventilator interact together - does pt do all the work or does the
vent?
- A/C= assist control set a tidal volume and set rate delivered- if pt attempts to
breath- the vent will sense it and then automatically deliver the preset TV
- EVERY breath whether delivered by the ventilator or if initiated by the pt -
will deliver the set tidal volume
- *the WOB is done by the ventilator
- Pressure ventilation and volume ventilation are methods of delivering tidal volume (TV)-
the amount of air that is entering the lungs
- Pressure vent:
- Gas delivered until prescribed pressure is reached-pressure maintained
for a prescribed period of inspiration
- There is no set tidal volume so TV must be continually monitored
- Resp. rate generally set faster with volume control modes-15-20 bpm
- advantage - prevents high pressures in delivery of breaths
®™ NURS 4581 Final Exam Study Success Notes
Acid Base Balance
Normal pH 7.35-7.45
The normal pH is maintained by the buffer system- respiratory and renal system
- Work together but at different speeds
Bicarbonate and carbonic acid buffer
- Stong acid converted into weak acid - resp. Or renal system can get rid of the weak
acids
Lungs
- Help maintain normal pH by excreting CO2 and water
- With sudden changes in blood pH, the resp system reacts within minutes and reaches
maximum effectiveness in hours
- Increased resp rate and depth= more CO2 expelled
- Decreased resp rate and depth= more CO2 remains in the blood- less expelled
Kidneys
- Maintain normal pH by reabsorbing or excreting bicarbonate and eliminating hydrogen
ions
- acidosis - generate additional bicarbonate and increase the amount of hydrogen ion
elimination
- Take 2-3 days to respond maximally to sudden changes in pH
PaO2- partial pressure of oxygen in the artery- oxygen that is dissolved in the blood
- P=partial bc there are other gases that are dissolved in the blood
- 80-100 mmhg
SaO2= oxygen saturation of aterial blood
- 90% or above
SpO2= oxygen saturation from pulse oximetry - noninvasive
Normal CO2=35-45
Normal HCO3= 22-28
ROME- Respiratory Opposite- Metabolic Equal
- Metabolic- pH value is equal to HCO3- both high or both low or both normal
- Respiratory- pH is low, CO2 high or vice versa
- If oxygenation is low- label with hypoxemia
Anytime pH is abnormal- uncompensated
Anytime pH is normal with other problems- compensated
Causes of Respiratory Acidosis
- Retention of CO2= not breathing -> caused by altered LOC, plastic bag over their head,
or resp failure
- S/S: shallow, weak ineffective breaths (guppy breathing) or no respirations,
disorientation, dyspnea, cyanosis or pallor
- Compensation is by the kidneys= hold onto HCO3, make more HCO3 or get rid of H+-
takes days to occur- nurse must intervene
- O2 controlled by resp rate-
®™ NURS 4581 Final Exam Study Success Notes
, NURS 4581 Final Exam Study Success Notes
- With compensated Resp. acidosis- pH will be normal, CO2 high and HCO3 high- HCO3
will be high because it is compensating for the acidosis- if it was a metabolic problem,
then the pH will be high
- Seen with chronic COPD patients- these patients have problems with exhalation
and frequently retains CO2 - kidneys have time to compensate- allowing for
normal pH
Causes of Metabolic Acidosis
- Too much acid production= ketoacids (DKA), poison ingestion, renal failure, diarrhea,
tissue hypoxia/lactic acid production
- S/S: Varied-DKA=acetone breath. Renal failure= edema. Kussmaul Respirations
- Respiratory compensation- remove acids/CO2. Resp. rate will be rapid and deep=
Kussmaul resp.
If patient is acidotic and HYPOkalemic- be cautious before correcting/treating acidosis
Causes of uncompensated respiratory and metabolic acidosis
- Too much acid production= DKA, poison, renal failure, diarrhea, tissue hypoxia, AND
resp. Failure (inability of the patient to remove CO2 and bring in O2)--- both systems are
broken
- S/S: varied or none at all
- Compensation: The renal and respiratory system are broken-> the pt is without the
ability to compensate and is most likely critically ill-> requiring mechanical ventilation
perhaps dialysis
Respiratory Failure, Mechanical Vent and Airway Management
Manifestations of Resp. Failure
- Use of accessory muscles, wheezing, rapid resp. rate, elevated HR/BP=SNS
stimulation
- If cyanosis were present=late sign
- Resp. failure is present when retained CO2 causes resp. acidosis and there is
hypoxemia
Treatment:
- Apply supplemental oxygen- humidified O2 can help liquefy secretions and reduce
drying of mucous membranes- if hypoxemia must give O2-lowest amount for least
amount of time- breathing treatment, elevate HOB, turn cough and deep breath if a post
surgical patient, steroid, assess hbg level
- Another option= CPAP-continuous positive airway pressure
CPAP
- The machine exerts positive pressure throughout respiratory cycle to help keep the
alveoli open (doesnt allow airway/alveoli to collapse)
- Delivered non invasively- may prevent intubation
- Keeping the alveoli open allows for a longer time for gas exchange
- Increases WOB- pt must exhale forcible against CPAP- use cautiously with pts with
myocardial conditions bc if we increase their WOB they can have an MI
Intubation
®™ NURS 4581 Final Exam Study Success Notes
, NURS 4581 Final Exam Study Success Notes
- Ensure oxygenation with bag valve mask before and after intubation
- After HCP inserts the ETT (endotracheal tube), prior to inflating the balloon of the ETT,
auscultate lung bases for bilateral breath sounds and look for chest rise/fall when giving
breaths with ambu bag
- If breath sounds are not heard- remove the tube bc pt is not getting O2
- Deliver O2 with BVM before HCP attempts to re-intubate
- Once bilat breath sounds are heard, inflate cuff/balloon of ETT to 20 mmhg (+/- 5 mmhg)
- Note measurement at lips and obtain chest x-ray confirmation of placement
- ETT will prevent the epiglottis form closing- the pt cannot swallow their saliva/oral
secretions
- ET balloon or cuff while inflated does not prevent the removal of the ETT
- Pt cannot speak when cuff is inflated
- Although the ET balloon is inflated, oral and gastric secreations can leak into the lungs
around balloon
Mechanical Ventilation
- Process where air (gas) is moved into and out of the lungs by a mechanical ventilator
- This is just a means of support to the pt
- Goals of ventilation are:
- Delivery of adequate oxygen
- Removal of CO2
- Reduce dyspnea
- Promote rest and reconditioning of fatigued respiratory muscles
- Once ventilator is initiated and the goals achieved AEB normal ABGs then the pt should
be weaned off the ventilator
Ventilator Settings
- Positive Pressure
- “Shoving” in air at the convenience of the ventilator
- May cause decrease in venous return- decrease CO- decrease BP- cause RAAS
activation
- Mode: How the pt and ventilator interact together - does pt do all the work or does the
vent?
- A/C= assist control set a tidal volume and set rate delivered- if pt attempts to
breath- the vent will sense it and then automatically deliver the preset TV
- EVERY breath whether delivered by the ventilator or if initiated by the pt -
will deliver the set tidal volume
- *the WOB is done by the ventilator
- Pressure ventilation and volume ventilation are methods of delivering tidal volume (TV)-
the amount of air that is entering the lungs
- Pressure vent:
- Gas delivered until prescribed pressure is reached-pressure maintained
for a prescribed period of inspiration
- There is no set tidal volume so TV must be continually monitored
- Resp. rate generally set faster with volume control modes-15-20 bpm
- advantage - prevents high pressures in delivery of breaths
®™ NURS 4581 Final Exam Study Success Notes
