exam 1 Flashcards
PaO2-partial pressure of oxygen dissolved in the arterial blood
- measure by Arterial blood sample
SaO2-arterial oxygen saturation of hemoglobin
-Direct measurement of oxygen in blood
SpO2-indirect measurement of the oxygen content of blood
-Measured via pulse oximeter
Hypoxemia-abnormally low PaO2
vocab
PaO2: 80-100 mmHg (70=hypoxemic) SaO2: 92-99% pH: 7.35-7.45 PaCO2 (lungs): 35-45 mmHg HCO3 (bicarb/kidney): 22-26 mEq/L
pH: acid 7.35-7.45 alk
PCO2: alk 35-45 acid
PCO3: acid 22-26 alk
normal values for ABG
pH-measure of hydrogen ion concentration in the blood
- When hydrogen ions accumulate, the pH drops-patient becomes acidotic
- When hydrogen ions decrease-pH raises-patient becomes alkalotic
PaCO2-partial pressure of carbon dioxide in arterial blood
-Regulated by the lung function
Respiratory acidosis
- Hypoventilation-carbon dioxide increases respiratory acidosis
- Occurs due to respiratory depression, decreased respiratory rate
Respiratory alkalosis
-Hyperventilation- carbon dioxide leaves body respiratory alkalosis
Bicarbonate- base
- Helps regulate pH
- Regulated by kidneys-metabolic process
- When bicarbonate increases –> metabolic alkalosis
- When bicarbonate decreases –> metabolic acidosis
functions/regulatory mechanisms
Definition: -PaCO2 >45mmHg (high) -pH <7.35 (low) -Build up of carbon dioxide in the lungs Causes: -*Over sedation or meds -Pulmonary embolism -*Hypoventilation -Bronchial obstruction -Heart failure -Central nervous system depression -Pulmonary edema -Pneumothorax -Cardiac arrest -COPD (retains CO2) -Pneumonia Signs and symptoms -Dyspnea -*Lethargy -Tachycardia -Confusion -Respiratory distress -Drowsiness -*Decreased responsiveness (can't breath r/t lethargy)
respiratory acidosis
Definition -PaCO2 <35mmHg (low) -pH >7.45 (high) Causes -Anxiety (breath fast, altered LOC --> blowing off too much CO2 --> alkalosis) -Pain -*Hyperventilation -Fever/sepsis -*Excessive mechanical ventilation (r/t breathing too much) Signs and symptoms -Confusion -Light headedness -Sweating -Dry mouth -Decreased concentration -Cardiac dysrhythmias -Deep, rapid breathing -Anxiety
respiratory alkalosis
See CO2 think lungs
Definition -HCO3 <22mEq/L (low) -pH <7.35 (low) Causes 1. Increased acids -*Renal failure -*Ketoacidosis (DKA/can be extremely low numbers) -Starvation -Alcoholism 2. Loss of base -Diarrhea Signs and symptoms -Headache -Confusion -Lethargy -Stupor/coma -*Kussmaul respirations (DKA)(rapid breathing r/t compensary mechanism for hyperventilation and to help kidneys)
metabolic acidosis
always low HCO3
metabolic = kidney and bicarb (bicarb is regulated by kidneys)
Definition -HCO3 >26 mEq/L -pH >7.45 Causes 1. Gain of base -Excess ingestion of antacids 2. Loss of acids -*Vomiting -*NG suctioning (can remove acid) -Hypokalemia -Hypochloremia -Diuretics (effects kidneys) Signs and symptoms -Tetany -Dizziness -Lethargy -Weakness -Coma -Nausea and vomiting -*Depressed respirations (r/t compensation of lungs)
metabolic alkalosis
Body should try to compensate if the patient has alkalosis or acidosis
-Renal or respiratory will try to compensate
If the problem is respiratory the kidneys should try to compensate
If the problem is renal the lungs should try to compensate
Can be fully compensated, partially compensated or uncompensated
Fully: good r/t body trying to fix it
- know in Full if pH is normalized
Partial: trying, not working - all abnormal
Uncomp: pH abnormal, either CO2 or CO3 is normal
compensation
If there is a metabolic-based pH imbalance:
- If it is metabolic acidosis- there will be an increase in respiratory rate and depth (high)
- If it is metabolic alkalosis- there will be a decrease in respiratory rate and depth (low)
respiratory compensation
If there is a respiratory based pH imbalance:
- Respiratory acidosis- there will be an increase in hydrogen secretion and HCO3 reabsorption (high)
- Respiratory alkalosis- there will be a decrease in hydrogen secretion and HCO3 reabsorption (low)
metabolic compensation
pH-normal
CO2-abnormal
HCO3-abnormal
Because the pH is normal, it indicates that one system has compensated for the other
fully compensation
pH is abnormal
CO2 is abnormal
HCO3 abnormal
Because both CO2 and HCO3 are abnormal, this indicates that one system has tried to correct the other system but hasn’t been completely successful
*Nothing is normal on ABG’s
partially compensation
pH is abnormal
EITHER CO2 or HCO3 is abnormal (1 is normal 1 is abnormal)
There is no indication that one system tried to correct the other
uncompensation
Nursing care is directly related to the cause of the imbalance!
What can the nurse do?
-Respiratory acidosis
–cause: narcotic, hypoventilation
–give narcan, wake them up, cough/deep breath, ventilate
-Respiratory alkalosis
–cause: hyperventilation
–correct: antianxiety (Ativan), pain meds, treat fever, *change vent setting
-Metabolic acidosis
–cause: DKA, renal failure, not enough bicarb
–correct: give bicarb, DKA=fix electrolyte imbalance and S/S
-Metabolic alkalosis
–cause: NG suction, vomit
–correct: turn suction down, antiemetic’s
nursing care for each resp and metabolic acid and alkalosis
Sudden and life threatening
Poor gas exchange: retain CO2 (acidotic) , inadequate oxygen (hypoxemia)
In patients with normal baseline abgs: -PaO2 55 or less -Paco2 >50 -Ph <7.35 In patients with chronic hypercapnia or hypoxemia: -Indicated by acute deterioration
acute respiratory failure
Large airway obstructions (food, mucous, tonsils, OSA, trauma, tumor)
Bronchial diseases (chronic bronchitis or asthma)
Parenchymal disease (severe pneumonia, pulmonary fibrosis)
Cardiovascular disease (cardiac pulmonary edema, PE)
Diseases of the pleura and chest wall (pleural effusions, pneumothorax)
Disorders of the respiratory muscles and neuromuscular junction (myasthenia gravis, muscular dystrophy, meds that paralyze respiratory muscles)
Disorders of the peripheral nerves and spinal cord (MS, ALS, guillain barrb)
Disorders of the central nervous system (stroke, seizures, narcotics)
causes respiratory failure
Affects all organs/tissues
From causes of resp. failure
low O2 in the blood –> tissue death
low Pa02
S/S
-Dyspnea*
-Cyanosis
-Restlessness: r/t lack of O2 to brain and gas exchange issue
-Confusion: r/t lack of O2 to brain and gas exchange issue
-Anxiety: r/t lack of O2 to brain and gas exchange issue
-Tachypnea
-Tachycardia
-HTN
-dysrhythmias*: low O2 to heart and high ectopy (PAC, PVC, afib) so give O2
hypoxemia
acute respiratory failure
Impairs cellular function From alveolar hypoventilation and ventilation-perfusion mismatch Respiratory acidosis hypoventilation causes high CO2 S/S -Dyspnea -Headache -Htn -Tachycardia -Tachypnea -Aloc-can become unconscious* -Use of intercostal muscles
hypercapnia
acute respiratory failure
if less responsive automatically check CO2 levels
Abgs: see S/S from hypoxemia, hypercapnia
Cxr: check infection , pneumonia, cause (do this 1st)
Sputum culture: infection in sputum, pneumonia, organism
Pfts
Ct: shows PE*, tumor
Labs- cbc (WBC infection/pneumonia), electrolytes (ones that cause acid base imbalance)
bronchoscopy: to see in lungs to check for mucous plugs/infection/biopsy and can do a wash out
Medications to treat the underlying cause of the respiratory failure
If cause is due to narcotic overdose-give narcan or reversal agent*
If cause is due to bronchospasm (copd/asthma)-give bronchodilator and corticosteroids to lower inflammation*
diagnostic procedures and meds for acute respiratory failure
- Increase oxygen-via nasal cannula, high flow mask, bipap (most invasive), ventilator
- This will improve cardiac output and improve tissue oxygenation
- Correct acid/base imbalance-ventilator will improve alveolar ventilation-may give sodium bicarb to improve resp and metabolic acidosis
- Monitor fluid balance (pt on vent has fluid imbalance - monitor daily weight, I/O)
- Treat underlying cause (if cardio/fluid OD give diuretics, if pneumonia give antibiotics)
- Monitor respiratory status closely!! May need immediate intubation!
- Will need to increase fio2 to increase pao2
- -Titrate down when able to prevent co2 retention
- Monitor oxygen saturations continuously* (put O2 on ear, foot, forehead and work with resp therapist)
- Frequent respiratory/neurological assessments (work of breathing, neuro)*
oxygen and airway management
if brain has poor perfusion then breathing won’t work as well
high CO2 is biggest S/S for altered LOC
Fio2-fraction of inspired oxygen-can go up to 100%
-30-100
Tidal volume-volume of air between inspiration and expiration
-amount of air chest holds
Peep-positive end expiratory pressure
-end of breath spurt on vent to keep the alveoli open
Rate-respiratory rate
-physician changes rate based on condition and CO2 rate
-can’t go below, but can go above setting
VENT SETTINGS: ALWAYS KNOW MODE, F102, rate, tidal volume and PEEP
vent vocab
Controlled rate that we set / volume mode
Patient can trigger own breaths but cannot go under set amount
Own breaths will be given full tidal volume by ventilator
Fully supports patient
initial mode we use
assist control/CMV continuous mandatory ventilation ventilator modes
Set Rate and tidal volume / volume mode
Patient can trigger own breaths but spontaneous breaths will not be supported by set tidal volume
Can add pressure support to this setting-will reduce work of breathing for patient
can use for weaning
Synchronized intermittent mandatory ventilation mode (SIMV)
ventilator modes
Assists spontaneous breathing by giving a high flow of gas to selected pressure level
Patient’s effort determines rate and tidal volume
Can adjust the pressure to achieve best tidal volume and resp. rate for patient
Can be used as weaning tool-will increase endurance of lung muscles
We only set pressure. We do not set tidal or rate (the patient sets that themselves)
pressure support ventilation modes