Test 4 - ABG, Acid/Base Balance - Pathophysiology & Pharmacology I - NURS 319 - Dr. Susan Prude - Spring 2017 - Southeastern Louisiana University

An emergency department nurse admits a client who has tried to commit suicide by taking an overdose of oxycodone (OxyContin). For which acid-base imbalance should the nurse assess this client? 1. Respiratory acidosis 2. Metabolic acidosis 3. Respiratory alkalosis 4. Metabolic alkalosis

1. The nurse should assess the client for respiratory acidosis because opioid analgesics cause respiratory depression, which increases CO2 retention and leads to a decrease in blood pH (acidosis).

A nurse interprets that a client's arterial blood pH of 7.50 is metabolic in origin. Which other abnormal laboratory finding should the nurse associate wit this pH imbalance? 1. Decreased serum potassium level 2. Increased serum chloride level 3. Decreased bicarbonate level 4. Increased serum calcium level

1. The nurse should associate a blood pH of 7.5 that is metabolic in origin (metabolic alkalosis) with a decrease in the serum potassium level. When the body is in a state of metabolic alkalosis, potassium is shifted into the cells and hydrogen ions are shifted out of the cells in an attempt to decrease blood pH (compensation). The shift of potassium into the cell results in a decreased serum potassium level.

ABG normal values pH PaCO2 HCO3

(acidosis) 7.35 - 7.45 (alkalosis) (alkalotic) 35 - 45 (acidotic) (acidotic) 22 - 26 (alkalotic)

4 types of chest pain 1. _________ Pleural pain 2. _________ Muscle pain 3. _________ Bronchi pain 4. _________ Cardiac pain A. Dull pain, worse with cough B. Substernal/chest area, not worsened or affected by resp. movement C. Bilateral, inferior portion of rib cage, worse w/movement D. Abrupt onset, worse with deep breathing and coughing, unilateral

1. D 2. C 3. A 4. B

ABG Four Questions

1. Is the ABG normal? No? Go to step 2 2. Is the pH Acidotic or alkalotic? Acidotic : < 7.35 Alkalotic: > 7.45 3. Is the cause respiratory or metabolic? PaCO2 > 45 = acidotic PaCO2 < 35 = alkalotic HCO3 > 26 = alkalotic HCO3 < 22 = acidotic 4. Is the cause compensated or uncompensated? (CUP) Compensated = pH is within normal limits Uncompensated = pH is outside normal limits Partially compensated = pH is outside of normal limits AND the opposite value is also outside of normal limits ex: pH 7.3 (acidotic) PaCO2: 48 (acidotic) HCO3: 27 (alkalotic)

Low blood oxygen levels. aka: reduced PO2 of arterial blood

hypoxemia

Which acid-base imbalance should a nurse associate with chronic diarrhea in a client diagnosed with Crohn's disease? 1. Respiratory acidosis 2. Metabolic acidosis 3. Respiratory alkalosis 4. Metabolic alkalosis

2. The nurse should associate metabolic acidosis with severe diarrhea secondary to Crohn's disease. Crohn's disease is an inflammatory bowel disease characterized by abdominal pain, weight loss, and diarrhea. Chronic diarrhea results in the loss of HCO3- through the stool, resulting in metabolic acidosis.

A nurse is caring for a critically ill client who begins exhibiting Kussmaul respirations. Which acid-base imbalance should the nurse associate with this type of respiration? 1. Respiratory acidosis 2. Metabolic acidosis 3. Respiratory alkalosis 4. Metabolic alkalosis

2. The nurse should associate the development of Kussmaul respirations with metabolic acidosis. Kussmaul respirations are very deep, rapid respirations that are not under the client's voluntary control. This type of breathing occurs when excess acids, caused by the absence of insulin, increase hydrogen ions and CO2 levels in the blood, triggering the body to excrete more CO2 by increasing the rate and depth of breathing (respiratory compensation).

A nurse is assessing a child who has a history of type 1 diabetes mellitus and is experiencing weakness, nausea, and anorexia of 4 days' duration. The child has not received the prescribed insulin during this illness and currently has a blood glucose level of 400 mg/dL. Which ABG pH is the nurse most likely to find? 1. Greater than 7.45 2. Less than 7.35 3. Approximately 7.40 4. Between 7.35 and 7.45

2. The nurse should expect the client's ABG pH to be less than 7.35 because this client is experiencing DKA, a life-threatening complication caused by insulin deficiency. DKA may be precipitated by an acute illness or infection, or it may occur in a client who is noncompliant with insulin therapy.

Respiratory Failure VQ mismatching __________, _______, _____________, _______ ________, ___________

hypoxemia COPD Atelectasis

Late response to asthma ___-____ hours post exposure. ________________ of the airways Exacerbations Release of mast cell mediators, activates basophils, eosinophils, & neutrophils. ⬇ in ___________ fxn Reduction in airway clearance Increase in airway responsiveness.

3-5 Inflammation ciliary

A 2-year-old child is brought to an urgent care clinic after ingesting a bottle of baby aspirin. For which acid-base imbalances should a nurse assess this child? 1. Respiratory acidosis and metabolic acidosis 2. Respiratory acidosis and metabolic alkalosis 3. Metabolic acidosis and respiratory alkalosis 4. Metabolic acidosis and metabolic alkalosis

3. The nurse should assess the client for metabolic acidosis and respiratory alkalosis because both occur with aspirin overdose. Aspirin, also known as acetylsalicylic acid, is a salicylate drug. A severe metabolic acidosis with compensatory respiratory alkalosis may develop with severe salicylate intoxication. FYI a client cannot have both metabolic acidosis and metabolic alkalosis at the same time.

Normal ventilation- oxygenation of blood- (V)- __L air/min Normal perfusion- blood supply (Q)- ___ L blood/min Normal V/Q ratio: _____

4 5 4/5 or 0.8

A nurse reviews the laboratory values of a newly admitted client. The nurse notes that the client has serum calcium level of 7.6 mg/dL. Which possible blood pH should the nurse associate with the development of hypocalcemia? 1. 7.25 2. 7.35 3. 7.45 4. 7.55

4. The nurse should associate a low serum calcium level with a possible blood pH of 7.55 (alkalosis). A decrease in hydrogen ion concentration (increased pH) may cause a decrease in calcium concentration in the blood.

Decreased O2 to tissues

hypoxia

VQ mismatching Abnormal distribution of ventilation and perfusion Can lead to ___________

hypoxia

Respiratory Failure Diagnosis PaO2 level - __________________ PaCO2 level - _________________ dependent on cause and symptoms

60 mmHg or less 45 mmHg or greater

An arterial PaO2 level less than ____ mm Hg (decreased) may indicate respiratory depression, decreased cardiac output, or carbon monoxide poisoning, which may result in an acid-base imbalance. An arterial PaO2 level greater than ____ mm Hg (increased) may indicate an increased ventilation rate or excess oxygen administration, which may result in an acid-base imbalance.

80 100

PaO2 > _________ (normal) - indicator of __________ oxygenation.

95% tissue

Hypoventilation Defined as: _____________________ Patho: Decreased volume of fresh air moving into and out of the lungs Causes: • Depression of __________ center o Drug ________, brain injury • Disease of nerve systems that supply respiratory muscles, exacerbation of lung disease and thoracic cage disorders _________-________ syndrome, __________, ________ chest

< 12 breaths per minute respiratory overdose Guillain-Barré syndrome COPD Flail chest

High V/Q ratio Ventilation _____ perfusion Adequate ventilation but poor _______________ Caused by ________ ________ d/t decreased blood flow to parts of the lungs

> perfusion pulmonary embolism

Low V/Q ratio Perfusion ____ ventilation Adequate perfusion but poor ________________ Shunting Causes: ________, ________ _________, ___________, ___________

> ventilation Asthma Pulmonary edema Pneumonia COPD

Diagnosis of asthma • History, pulmonary function tests, __________________ o Hypoxemia o Normal _____________________ o Prolonged or extended time in ________ _________

ABG results PaO2 - 96-100% respiratory acidosis

Hypoxemia Diagnosis tools: _____, pulse _________, pulmonary ________ tests Treatment: correct the cause, nasal __________ or ETT (esopho tracheal tube)

ABGs oximetry function cannula

A nurse is assessing a client who may be experiencing metabolic alkalosis. Which signs and symptoms, if noted during the assessment, should the nurse associate with this particular acid-base imbalance? Select all that apply. 1. Cyanosis 2. Muscle cramping 3. Lethargy 4. Shallow respirations 5. Deep respirations

ANSWER: 1, 2, 4. Rationale: 1. The nurse should associate cyanosis with metabolic alkalosis; it a sign of inadequate oxygenation caused by slow, shallow respirations. 2. Muscle cramping is a sign of metabolic alkalosis resulting from the hypocalcemia and hypokalemia that accompany metabolic alkalosis. 3. Lethargy is a sign of metabolic acidosis, not metabolic alkalosis. Metabolic alkalosis results in irritability, twitching, and confusion. 4. Metabolic alkalosis is characterized by shallow respirations and a decreased respiratory effort secondary to skeletal muscle weakness. 5. Respiratory, not metabolic, alkalosis is characterized by an increased rate and depth of respirations. Manifestations of respiratory and metabolic alkalosis are similar, with the exception of respiratory patterns.

A nurse is caring for a client diagnosed with pancreatitis. The client's blood pH is 7.20. When reviewing the client's laboratory data, which other abnormalities should the nurse anticipate? Select all that apply. 1. Decreased bicarbonate (HCO3-) level 2. Decreased partial pressure of oxygen (PaO2) level 3. Normal partial pressure of carbon dioxide (PaCO2) level 4. Increased serum potassium (K+) level 5. Increased serum calcium (Ca2+) level

ANSWER: 1, 3, 4. Rationale: 1. The nurse should anticipate that the client will have a decreased HCO3- level because the inflamed pancreas cannot produce enough bicarbonate ions to balance the free hydrogen ions in the blood. 2. The client's PaO2 would be either normal or increased as the client's respiratory rate increases to "blow off" CO2 (respiratory compensation). 3. The client's PaCO2 level would be either normal or increased because the respiratory function is not impaired, and the client may be "blowing off" CO2 to compensate for the acidotic state. 4. Serum K+ levels are often increased in acidosis as the body attempts to buffer the blood pH by moving potassium out of the cells and into the bloodstream to counteract the hydrogen ions moving into the cells. 5. The client's serum CO2+ level would not be affected by metabolic acidosis

A nurse is caring for multiple clients on a medical- surgical unit. Which client should the nurse identify as being at greatest risk for respiratory acidosis? 1. A client who is extremely anxious 2. A client with uncontrolled type 1 diabetes mellitus 3. A client with COPD 4. A client with gastroesophageal reflux disease

ANSWER: 3. Rationale: 1. The client who is extremely anxious is at risk for respiratory alkalosis secondary to possible hyperventilation. 2. The client with uncontrolled type 1 diabetes mellitus i at risk for metabolic acidosis. 3. The nurse should identify that the client with COPD is at greatest risk for respiratory acidosis because this client's respiratory function is impaired; potential CO2 retention may decrease blood pH, resulting in respiratory acidosis. 4. The client with gastroesophageal reflux disease is at risk for metabolic alkalosis because these clients typically consume excessive antacids to control their reflux. Antacid contain HCO3 -, which increases blood pH (alkalosis).

Acidosis vs alkalosis? Causes CNS depression. Disorientation to coma.

Acidosis

If metabolic disturbances causes an acid-base imbalance, the lungs begin to compensate. a. ___________ - is caused by a lack of bicarbonate, the lungs increase their rate to blow off CO2, raising pH levels. b. ____________ - excess bicarbonate levels signal the lungs to decrease their rate, in order to retain CO2, decreasing pH levels.

Acidosis Alkalosis

Metabolic helps respiratory disturbances. a. __________ - PaCO2 is high, the kidneys retain bicarbonate, and excrete acid, increasing pH levels. b. __________ - PaCO2 level is low, the kidneys excrete bicarbonate, hold on to more acid, decreasing pH levels.

Acidosis Alkalosis

Asthma Symptoms: _________ attack with early response: Immediate release to an allergen 10-20 minutes Worse at _______ Bronchospasm Prolonged expansion May need ____________

Acute night bronchodilators

Atelectasis causes

Airway obstruction Pneumothorax Pleural effusion

Symptoms of ______________. tachypnea, tachycardia, dyspnea, cyanosis, hypoxemia, diminished chest ___________, absence of ________ sounds, ineffective __________ reflex, retractions

Atelectasis expansion breath cough

Incomplete expansion of a lung or portion of the lung. A common post-op infection.

Atelectasis (primary or secondary)

3 types of asthma

Atopic / extrinsic Non-atopic / intrinsic Severe

Represents an increase or decrease in the buffer base. A BE greater than +2 means that either an acid has been removed or a base has been added. A BE less than -2 means that an acid has been added or a base has been removed. Normal BE -2 to +2 meq/L

Base excess

Can affect adults and children Patho: chronic inflammatory disease of the airways causing recurring symptoms. _________- attack, bronchospasm, ineffective cough, increased energy needs, accessory muscle use, dyspnea, fatigue, ventilation and perfusion mismatching 3 types:

Bronchial asthma

Obstructive airway disorders

Bronchial asthma COPD (emphysema and chronic bronchitis) Bronchiectasis Cystic Fibrosis

Hypercapnia Results in increased _____ levels Respiratory muscle disorders: ___________________________ Changes in neural control: ________________________________ Increased production of CO2: ___________________________________

CO2 ⬇energy supply and ⬆ muscle fatigue CO2 and H20 form carbonic acid - stimulates respiration. Hypoxic patients - ⬆high flow O2, loose stimulus for respiration, leading to resp. failure and death Metabolic rate changes d/t fever, 13% ⬆ for every +1 °C temp above normal Diet - low carb/high glucose levels

Type of pain where it feels like an elephant is on your chest

Cardiac pain

Diagnosis of pleural effusion

Chest x-ray CT results Drainage appearing purulent, bloody, with ⬆proteins or milky

Nursing interventions for pleural effusion

Diet - low fat diet (chylothorax) Meds: diuretics & antibiotics

Transfer of gases between alveoli and pulmonary capillaries

Diffusion

Treatment of asthma

Eliminate causative agents Education Medications Beta-2 adrenergic agonist Anticholinergics Glucocorticoids Leukotriene modifiers

Nursing interventions for pleurisy

Encourage coughing and deep breathing Keep head of bed elevated 45°

Type of asthma? Type 1 hypersensitivity reaction Caused by exposure to allergen/antigen Seen in childhood

Extrinsic / atopic

_________ _________ occurs with... a thick alveolar capillary membrane ⬇ surface area ⬇ membrane permeability

Impaired diffusion

________ moves in the same direction as pH

HCO3

_________reflexia and ___________ are caused by the hypocalcemia that may accompany acidosis.

Hyper paresthesias

Symptoms of respiratory failure

Hypoxemia hypercapnia Increased resp drive Retractions Anxiety Fatigue

Type of asthma? Triggers include... Exercise induced Respiratory tract infection Inhaled irritants Emotional Drug/chemicals

Intrinsic / non-atopic

Anticholinergic used for long term and maintenance treatment of asthma

Ipratropium (Atrovent)

__________ is the site for phosphate buffer system

Kidneys

________ asthma attacks Tachypnea, prolonged expiration, mild wheezing, cough

Mild

pneumothorax diagnosis & treatment. Chest x-ray, CT scan _________ ____________ w/ tension pneumothorax Covering of the area, chest tube Correct ______________

Needle decompression Hypoxemia

Impaired diffusion can be corrected with supplemental ____ Not enough oxygen is getting into the lungs d/t - ____________ lung disease - __ __ __ __ - Pulmonary Edema - _____________

O2 Interstitial ARDS - acute respir. distress syndrome Pneumonia

________ levels move in opposite directions as pH

PaCO2

The ____O2 varies with age, after age 60 the ___O2 may drop below 80 without signs of hypoxia

PaO2

Flow of blood in the adjacent pulmonary capillaries (____)

Perfusion (Q)

Lung inflation disorders

Pleuritis (Pleurisy) Pleural effusion Pneumothorax Atelectasis

_______________ asthma attacks Fatigue, diaphoresis, anxiety, short speech, breath sounds inaudible, ineffective cough, onset of respiratory failure

Progression

Measures the percent of hemoglobin actually carrying O2 as opposed to the percent that it could (100%)

SaO2

Type of asthma? Persistent asthma despite high dose/long term meds. Requires high dose corticosteroids ⬆ risk for fatal attack

Severe

________ asthma attacks. Accessory muscle use, distant breath sounds with air trapping, loud audible wheezing

Severe

Type of pneumothorax? Risk factors: tall & thin patient, smoker, asthma, emphysema patient Symptoms: tachycardia, dyspnea, asymmetrical chest wall, decreased breath sounds on affected side

Spontaneous pneumothorax

3 types of pneumothorax

Spontaneous pneumothorax Traumatic pneumothorax Tension pneumothorax

Type of pneumothorax? Trachea deviates towards unaffected side, shock, faint heart sounds, life threatening, tachycardia

Tension pneumothorax

Serum potassium levels are _____________ in the presence of acidosis as the body attempts to buffer the decrease in blood pH. Serum potassium levels are ___________ in the presence of alkalosis, causing central nervous system, neuromuscular, cardiac, and respiratory changes

increased ⬆ decreased ⬇

Treatment for pleural effusion Treat the cause Large effusion o ___________ to remove fluid o _________ tube

Thoracentesis chest

Type of pneumothorax? Risk factors: penetrating trauma, dislocated ribs Symptoms: same as tension pneumothorax

Traumatic pneumothorax

Treatment for pleurisy

Treat underlying cause and inflammation NSAIDS, Antibiotics

Respiratory Failure Patho: Impaired gas exchange d/t heart failure, lung failure, or both. Impaired ventilation (3 things) ________________________________________

Upper resp. obstruction - epiglottitis, laryngospaspm, tumors Weakness/paralysis of resp. muscles - brain tumors, drug OD, Guillain-Barre syndrome Chest wall injury d/t trauma

Pleuritis (Pleurisy) Patho: Inflammation of the parietal and visceral pleura Pleura is a thin, double-layered serous membrane that encases the lungs Causes: _________ __________ (usually in young/healthy people) _____________, cancer

Viral infection pneumonia

Think of CO2 as an _________

acid

Think of CO2 as an _______, when it combines with water in the body __________ ________, H2CO3, is produced

acid carbonic acid

More H+ = ___________, pH___ Fewer H+ = _____________, ph ____

acidic, ph ⬇ alkalotic, ph⬆

A positive Chvostek's sign and muscle weakness results from the hypocalcemia that may accompany ____________.

acidosis

DKA displays Kussmaul respirations to compensate for ____________

acidosis

Renal failure, fever, and dehydration are all risk factors for metabolic ___________

acidosis

Substances that cause __________ when ingested include ethanol, methyl alcohol, and acetylsalicylic acid (aspirin).

acidosis

Treatment for Atelectasis Reduce airway ____________, _____________, deep ___________, supplemental ____, _______ position A pt's cough response will decrease d/t medications and pain Ineffective cough reflex causes a decrease in tidal volume and inadequate alveolar expansion, the sputum viscosity increases and goes to the depended areas of the airways, this typically occurs in the right middle lobe

airway obstruction ambulation breathing O2 body

Acidosis vs alkalosis? Causes CNS over stimulation Tingling sensations in extremities, tetany, convulsions

alkalosis

Anxiety, confusion, or loss of memory; tingling hands; and headache all are signs and symptoms of respiratory __________. Hyperventilation (respiratory rate of 32 breaths per minute) is the cause of the imbalance

alkalosis

Hypoxia Results in ___________ metabolism, lactic ___________, hypoxemia

anaerobic acidosis

PaO2 Measures the partial pressure exerted by oxygen dissolved in _________ blood

arterial

SaO2 is an indicator of ____________ oxygenation

arterial

Serum __________ levels are decreased ⬇ in the presence of alkalosis, causing central nervous system, neuromuscular, cardiac, and respiratory changes. Serum __________ levels are increased ⬆ in the presence of acidosis as the body attempts to buffer the decrease in blood pH.

calcium chloride Hypocalcemia associated with alkalosis.

Respiratory Failure treatment 1st - ____________________________ ______________ ventilation Medications o __________ agonists o Antibiotics o ____________ o _____________ (calms them down)

correct impaired gas exchange problem Mechanical Adrenergic Corticosteroids Benzodiazepines

Insulin administration causes serum potassium levels to __________ rapidly

decrease

Cerebral edema may cause respiratory ___________, increasing the client's risk for respiratory ___________

depression acidosis

Oxycodone is an opioid, and opioids cause respiratory __________ by decreasing the function of the brainstem neurons that trigger breathing movements. Oxycodone use places the client at risk for __________ __________.

depression respiratory acidosis

Respiratory Failure Impaired diffusion: ___________ lung disease, ______, pulmonary __________, pneumonia

interstitial ARDS edema

Hypoxemia Symptoms: cyanosis, restless, ____________________, stupor, _______, dyspnea, tachycardia, ____________, & ________________

mood changes coma tachypnea retractions

SpO2 Indicator of oxygen saturation of _________ __________ Readings from sensor on fingers, ears, toes, or forehead Not accurate with ____________, _____________, ___________

peripheral circulation fake nails, nail polish, cool extremities

Symptoms for _________ _________ Dullness to percuss and diminished breath sounds, dyspnea, cyanosis, shock symptoms, pleuritic pain

pleural effusion

Symptoms of pleurisy (pleuritis)

pleuritic pain shallow breathing d/t pain pleural friction rub (leather on leather sound) Fever (seen with viral infection & pneumonia)

Treatment for a Malignant pleural effusion

sclerosing agent = thickening or hardening to prevent buildup of fluid

Flow of gases into and out of the alveoli of the lungs Alveolar _____________ - amount of air available at the alveolar level for gas exchange (___)

ventilation (V)

Pleural effusion Patho: too much fluid in pleural cavity for removal Causes: (4 of them)

⬆ capillary pressure (CHF) ⬇ colloidal osmotic pressure (low albumin levels) ⬆ negative intrapleural pressure (atelectasis, chest trauma) Impaired lymphatic drainage (pneumonia, TB)