ABGs / Problems With Oxygenation Flashcards
Normal pH
7.35-7.45
What is compensation?
Body’s means of returning pH to normal (buffering)
3 systems that compensation is regulated by, and how quickly do these occur?
Chemical: immediate
Respiratory: within minutes to hours
Kidney: hours to days
When monitoring ABGs, what is being assessed?
Tissue oxygenation
Alveolar ventilation
Acid-base balance
Goal of analysis = treat primary problem
Normal PaCO2
34-45 mm Hg
What is it called if PaCO2 < 35
Respiratory alkalosis
What is it called if PaCO2 > 45
Respiratory acidosis
What does the bicarbonate determine?
Metabolic problem
Normal HCO3
22-26 mEq/L
What does it mean if HCO3 is < 22?
Metabolic acidosis
what does it mean if HCO3 is > 26?
Metabolic alkalosis
What does ROME stand for?
Respiratory
Opposite
Metabolic
Equal
What is respiratory acidosis caused by?
Hypoventilation (opioids)
Respiratory failure
COPD
How is respiratory acidosis compensated for?
Kidneys conserve HCO3- and secrete H+ into urine
What is respiratory alkalosis caused by?
Hypoxemia from acute pulmonary disorders
Hyperventilation (can be from pain, anxiety, DKA, head injury
How is respiratory alkalosis compensated for?
Expect kidneys to compensate, but compensation is rare
What is metabolic acidosis caused by?
Excess acid from:
Ketoacidosis (DKA)
Lactic acid accumulation (shock, seizures, Metformin, aspirin)
OR
Bicarbonate deficit from:
Severe diarrhea (loss from lower GI)
Kidney disease (end stage ~uremia)
How is metabolic acidosis compensated for?
Increased CO2 secretion by lungs (Kussmaul respirations)
Kidneys excrete acid
What is metabolic alkalosis caused by?
Bicarbonate excess caused by:
Ingestion of antacids
Pancreatic secretion of HCO3-
OR
Loss of acids from:
Prolonged vomiting or gastric suction (loss from upper GI)
How is metabolic alkalosis compensated for?
Renal excretion of HCO3-
Decreased respiratory rate to increase plasma CO2 (limited help)
If someone is about to have their ABCs taken, what precautions do you need to take?
No changes to O2 therapy 15 minutes before
So if someone has order to change O2 flow rate,
1 - change O2
2 - wait 15 min before getting ABG
What does a CT of the chest look at?
Scans lungs in layers
Nursing considerations when a pt has a CT or chest ordered
Look to see if it’s ordered with or without contrast dye (sometimes both)
If with dye, check to see if pt is allergic to contrast/iodine/shellfish
Teach pt they will feel warm and flushed with injection
Encourage hydration before and after to flush out contrast
After CT: monitor renal function
Nursing considerations for a pt having an MRI
Screen for metal (including implantable devices, surgical hardware)
Remove all metal (jewelry, hearing aids)
Address claustrophobia (sedation may be necessary)
What does a V/Q scan consist of?
Ventilation - inhale moisture of O2 with radioisotopes
Perfusion - IV injection of radioisotope
Why is a V/Q scan performed?
Usually to check for pulmonary embolism
Nursing considerations for V/Q scans
Pt must be able to follow commands, be able to lie still
Pt must have IV access
No prep, takes about an hour
What does an SpO2 monitor check for?
Oxygenation
Normal oxygen
94-99%
Oxygenation that needs prompt treatment
Below 91%
oxygenation that is life threatening
Below 70%
What should be done if SpO2 shows a questionable reading
Repeat
What is SaO2?
Same as SpO2, measured by ABGs
What does Capnography monitor?
Ventilation
(Detects resp depression before SpO2)
What is a normal Capnography range?
35-45 mm Hg
Why would someone have a high EtCO2?
(High Capnography reading)
Partially obstructed airway
Hypoventilation
What do pulmonary function tests measure?
Lung volumes and airflow
What is a thoracentesis?
Aspiration of pleural fluid
(Needle into chest wall to obtain specimens, remove pleural fluid, or instill medication)
What needs to be done after every thoracentesis?
Chest Xray
Nursing actions after a thoracentesis
Encourage deep breaths
Auscultate breath sounds
Ensure CXR obtained
Dressing to site
Possible complications after a thoracentesis
Hypoxia
Infection
Pneumothorax
(Possible chest tube)
What is a bronchoscopy?
Direct visualization of bronchi through scope via nose or mouth
Nursing management for a bronchoscopy
NPO 6-12 hours before (sedation)
NPO until gag reflex returns after (recovery from sedation)
Monitor for complications:
- hemorrhage
- pneumothorax
- infection
How is a transbronchial biopsy done?
Can be performed during bronchoscopy
How is a transthoracic biopsy done?
Percutaneously (requires CXR post procedure to assess for pneumothorax)
How is a VATS biopsy done?
(Video-assisted thoracoscopic surgery)
Scope with camera inserted through a trocar
(Chest tube needed post procedure)
How is an open biopsy done?
Surgical procedure
(Chest tube needed after)
How would you know if your pt had a pneumothorax?
Pain on affected side (at end of inspiration and expiration)
Decreased lung sounds on affected side
Trachea shift to unaffected side
Dyspnea
Fast RR, HR
New cough
Cyanosis
Treatment for a pneumothorax
O2
Raise HOB
Call HCP
Why would a pt have a chest tube?
Pneumothorax (air)
Hemothorax (blood)
Pleural effusion (fluid)
Where are chest tubes placed?
Into the pleural space, not the lung
To remove air: upper chest, near apex
To remove blood/drainage: further down chest
Nursing actions for pt with a chest tube
*#1 = good resp assessment / changes (check chest tube connection)
Assess CT insertion site dressing and monitor
Monitor drainage
Monitor bubbling in chamber
Check suction - matches order
Maintain drainage system lower than chest
Mark drainage level at end of shift
What does a gram stain culture test for?
Gram positive/negative bacteria
What does an acid-fast bacillus test for?
Indicated possible TB
What does a culture & sensitivity (C&S) test for?
Allows growth and isolation of microorganisms
Determines appropriate medication
What does cytology test for?
ID abnormal cells (to look for malignancies)
