Acid-Base Balance

Question 1

Resp. Acidosis pH + Causes

Answer 1

• Blood pH: < 7.5
• Causes:
  
  • Hypoventilation: causes CO2 to be retained
  • COPD: most common cause bc bronchitis produces sputum that builds up in bronchioles which makes excreting CO2 more difficult
    
    • In emphysema, there’s less alveolar surface space to allow for CO2 out
  • Pneumonia: inflammation phlegm or sputum traps CO2 in blood
  • Extensive atelectasis: traps CO2 in blood bc there’s less surface space for CO2 to get out
    
    • Chest wall injury (fall, rib fx)
    • Sx causing pain w/ respiration
    • Drug side-effects causing respiratory depression (Ie. opioids, gabapentin, muscle relaxants, benzodiazepines causes sedation and possible hypoventilation)
  • High ammonia lvls in pts w/ liver disease
  • If pt on O2 mask and flowmeter isn’t set high enough ⇒ pt rebreathes their own CO2 lvls ⇒ ↑ CO2 blood lvls ⇒ resp acidosis

Question 2

Resp. Acidosis S&S

Answer 2

• Headache
• Light-headedness
• ↓ LOC: confusion, lethargy, coma
• Dysrhythmias: irregular heart rhythms
• Note: all aforementioned S&S are in addition to assessing underlying cause like PNA & adventurous breath sounds

Question 3

Resp. Acidosis Interventions

Answer 3

• ↑ Mobilization so they take deeper breaths bc of that
• Drug therapy:
  
  • Bronchodilators: to open lungs more
  • Antibiotics: to clear infections and ↓ inflammation
  • Mucolytics: to break up mucous for pt to cough out
    
    • Hydrate them so they can move those secretions out !!!
• Pain meds
• HOB ↑, Incentive Spirometer (IS), deep breathing exercises
• Change/↓/dc any of those sedating meds
• Masks:
  
  • Simple masks: 6 - 12 L/min
  • Non-rebreathers: 10 - 15 L/min (At least 10 L/min bc it’s fast and pushes CO2 out of those side holes to allow pt to breathe in O2 and not rebreathe their CO2)
  • Ventilation Support:
    
    • Continuous Positive Airway Pressure (CPAP) Airflow: provides single set of pressure throughout sleep ⇒ provides support for inhalation bc machine provides little more pressure to open up airways so pt can ventilate (More common for sleep apnea)
    • Bilevel Positive Airway Pressure (BiPAP) Airflow: provides two distinct pressure settings for inhalation and exhalation ⇒ pt gets inhalation and exhalation support to keep alevoli open longer to provide more time for gas exchange ⇒ CO2 excreted and O2 can oxygenate blood (More common in sedated and hyperventilating pts)

Question 4

Resp. Alkalosis Blood pH & Causes

Answer 4

• Blood pH: > 7.45
• Causes:
  
  • Hyperventilation: blowing off too much CO2
  • Acute pain: pt breathing fast and excreting too much CO2 to cope w/ pain
  • Anxiety or Panic attacks can cause hyperventilation
  • Sobbing
  • Salicylate (aspirin) side-effect

Question 5

Resp. Alkalosis S&S

Answer 5

• ↑ RR
• Light-headedness
• Numbness and tingling of fingers, toes, circumoral region
• Confusion / ↓ LOC
• Dysrhythmias

Question 6

Resp. Alkalosis Interventions

Answer 6

• Alleviate anxiety / panic attack
  
  • Calming measures
  • Benzodiazepines can cause addiction and sedation if given too frequently/much
• Provide pain relief
• Discontinue aspirin

Question 7

Metabolic Acidosis Blood pH + Causes

Answer 7

• Blood pH: < 7.35
• Causes:
  
  • Diabetic Ketoacidosis: occurs in diabetic pts where body can’t use blood glucose for energy due to lack of insulin and their body start to break down fat instead ⇒ produces acidic chemicals called ketones ⇒ builds up in blood ⇒ leads to acidotic state
  • ESRD: kidneys are supposed to excrete hydrogen ions and since their kidneys aren’t working properly, their H+ ions aren’t excreted
  • Diarrhea: causes loss of bicarbonate, a key buffer in this whole acid-base balance, bc colon reabsorbs bicarb but w/ diarrhea it doesn’t get that chance to reabsorb

Question 8

Metabolic Acidosis S&S

Answer 8

• Kussmaul’s respirations: ↑ RR and depth of respiration
• ↓ LOC: lethargy, confusion, coma
• Abd pain
• Dysrhythmias

Question 9

Metabolic Acidosis Interventions

Answer 9

• Prevent/correct underlying causes/problems !!!
• Ie. give insulin
• Ie. dialysis
• Ie. give sodium bicarbonate (PO/IV)
• Ie. controlling diarrhea

Question 10

Metabolic Alkalosis Blood pH + Causes

Answer 10

• Blood pH: > 7.45
• Causes:
  
  • Excessive vomiting
  • NGT suctioning
  • Excessive antacid use w/ sodium bicarbonate
    
    • Pts w/ chronic heartburn or ulcers may be taking too many acids to control pain and those contain sodium bicarbonate, buffer that binds to acids ⇒ causes alkalosis

Question 11

Metabolic Alkalosis S&S

Answer 11

• Light-headedness
• Numbness and tingling of fingers, toes, and circumoral region
• Muscle cramps
• Confusion followed by ↓ LOC
• Dysrhythmias

Question 12

Metabolic Alkalosis Interventions

Answer 12

• Alternative Tx if their using antacids
• Resolve vomiting: get rid of trigger odors in room or give them ondansetron (anti-nausea)
• Promote GI motility w/ early mobilization to ↓ NGT need