acids and bases

acids

release hydrogen ions which increases hydrogen

bases

binds to hydrogen ions which decrease hydrogen

buffers

release and bind hydrogen ions responsible for homeostasis

normal pH

7.35 to 7.45

what is the first line of defense?

physiological (chemical buffers) like phosphate, hemoglobin, protein, albumin

what is the 2nd line of defense?

Respiratory which is fast works within 5-15 mins

what is the 3rd line of defense?

Renal acid-base control which is slower and takes at least 24hrs to days, movement of acids, bicarb, and ammonium

acids increase hydrogen which can cause?

the overproduction of acids that causes the release of hydrogen ions or an under elimination of acids that causes retention of hydrogen ions

acids can cause imbalances in what electrolytes?

calcium, potassium, sodium

most common base and which systems are affected by imbalance of bases?

bicarb, cardiovascular, muscular, and nervous systems

respiratory compensation (2nd line)

retains or removes CO2 and begins compensation in 5-15 mins

respiratory compensation PaO2 80-100

partial pressure of oxygen in arterial blood, looks at how oxygen binds to hemoglobin

respiratory SaO2

oxygen carrying capacity of hemoglobin

respiratory CO2

compensates for metabolic issues and is a natural byproduct of cellular metabolism, and increase indicates acidosis, a decrease is alkalosis

respiratory PaCO2

partial pressure of CO2 in arterial blood normal level is 35-45, above 45 is acidosis below 35 is alkalosis

H2CO3 carbonic acid

CO2 combines with water you get carbonic acid, increased CO2 increases carbonic acid

metabolic- bicarbonate

kidneys are the 3rd line of defense, most effective but slowest acting buffer, normal HCO3 is 22(acidosis)-26(alkalosis)

how do the kidneys help compensate?

secretes and absorbs hydrogen and bicarb (pee), and movement of bicarb, formation of acids, and ammonium

when should the nurse draw for an ABG? (9)

respiratory/kidney failure, shock, uncontrolled diabetes, COPD, metabolic disease, drug overdose, asthma, depression, trauma

uncompensated

ph is abnormal and either the PaCO2 or HCO3 is also abnormal, the opposite system has not tried to correct the imbalance

partially compensated

ph is abnormal and both the PACO2 or HCO3 is also abnormal, the opposite system has attempted to correct for the other but has not been completely successful

fully compensated

ph is normal and both PaCO2 and HCO3 are abnormal, normal ph indicates that both systems have been working to make the ph normal

which over the counter meds should we assess for patients with imbalances?

antacids and diuretics

cues for imbalances

changes in respiratory pattern and status, mental health status, nail beds and mucous membranes, dehydration, potassium levels, pulses

respiratory acidosis low ph, elevated CO2 indications

altered ventilation HYPOventilation, CO2 retention, inadequate chest expansion, airway obstruction, decreased alveolar capillary diffusion, asthma, COPD, pneumonia, opioid overdose, head injury, or head trauma

respiratory acidosis interventions

maintain an airway, monitor ABGs, vitals, oxygen, pulmonary hygiene, incentive spirometer, drug therapy, ventilatory support, monitor potassium

respiratory alkalosis, high ph low CO2 indications

increased alveolar ventilation HYPERventilation, fever (+RR), sepsis, increased mechanical ventilation, and anxiety, could experience perioral tingling

respiratory alkalosis interventions (5)

reducing ventilation rate (brown bag), assist with ADLs, identify and eliminate causative agent, reduce fever, eliminate source of sepsis

metabolic acidosis causes

retention of stomach acid, hydrogen ion overproduction or under elimination, lactic acidosis from poor perfusion or hypoxemia (DKA/starvation/heavy exercise), COPD, kidney failure, reflux, travelers diarrhea, pancreatic, liver failure, diarrhea

metabolic acidosis signs and symptoms

kussmaul breathing, anorexia, fruity breath, nausea, vomiting, diarrhea, sweating, abdominal discomfort, warm flushed dry skin (dehydration)

treatment for metabolic acidosis

treat underlying cause, parenteral fluid/nutrition replacement, antidiarrheals, dialysis (for CKD and increased K+)

metabolic alkalosis (8)

too much stomach acid out, vomit, NG suctioning, base excess caused by intake in bicarb, carbonates, acetates, citrates, and antacid overdose (binds to stomach acid and lowers it)

metabolic alkalosis treatment

discontinue or lower NG suctioning, antiemetic, hemodynamic monitoring, LOC, IV fluid, electrolyte supplements