Nursing Process - Acid/Base Balance: Lec 9
Assessing
Acute and chronic illness, trauma and certain therapeutic interventions may place a patient at risk for acid-base imbalances These can seriously compromise the patient's health status and may prove life threatening
What is being measured by these numbers?
Alveolar ventilation (by pCO2) Hypoxia (by pO2 and O2 Sat) Acid base status (by pH)
Conditions Respiratory Acidosis
COPD, pulmonary edema, pneumothorax, overdose, severe pneumonia, ARDS, resp. failure, post anesthesia; over sedation
3rd step
Determine whether body is compensating for the pH change Problem - respiratory the renal system assists in compensation either by increasing or decreasing HCO³ Problem - metabolic the respiratory system assists by regulating CO² Compensation PaCO² and HCO³ - point in same direction
Nursing Process - Evaluating
Evaluation must be ongoing with acid-base imbalances Evaluate and readjust plans and interventions throughout nursing care Effectiveness of the plan should result in the client being able to practice self-care behaviors to maintain acid-base balance
Nursing Process - Outcome Identification and Planning
Exhibit signs and symptoms of restored balance or homeostasis after initiation of treatment Practice self-care behaviors to promote acid-base balance and respond appropriately to the body's signals of impending acid-base imbalance
2nd step
If a change in pH is present, determine if it is respiratory (PaCO² ) or metabolic (HCO³)
Nursing Process - Diagnosing
Ineffective Breathing Pattern related to compensatory mechanism of lungs (hypoventilation or hyperventilation) Anxiety related to hyperventilation
1st step Interpreting ABGs
Is to determine whether the pH is normal, alkalotic or acidotic Normal 7.35 -7.45 Acidotic < 7.35 Alkalotic > 7.45
Arterial Blood Gases (ABGs)
Laboratory tests commonly used to determine the adequacy of oxygenation and ventilation, as well as in the assessment and treatment of acid-base imbalances Findings are obtained through analysis of an arterial blood sample pH of blood indicates balance or impending acidosis or alkalosis The blood's oxygenation and carbon dioxide gas values are also reported Provides information regarding the effectiveness of the respiratory system
4th step
Look at the total picture and determine whether compensation has occurred Absent if: pH abnormal, one component abnormal, one normal Partial if: pH abnormal, one component abnormal, one beginning to change Complete if: pH abnormal, one component abnormal, second changed to move pH within normal range
What does the ABG tell you about your patient?
Obtains baseline information about pt. Assesses extent of lung disease Acid - base balance Determines if O2 therapy (or mechanical ventilation) is successful.
Corrective actions involve medical and nursing interventions to promote a return to homeostasis
Pharmacologic agents Mechanical ventilation Monitor intake/output
The partial pressures are indicated by "P", the "a" indicates an arterial specimen
The partial pressure of carbon dioxide is abbreviated PaCO² The partial pressure of oxygen is abbreviated PaO²
Additional ABG Values
The partial pressure of oxygen - PaO² and Oxygen saturation - SaO² Directly reflect the adequacy of oxygenation and ventilation
Nursing Process - Implementing
Treatment is directed at improving ventilation possibly through mechanical assistance Correction of underlying problem is the mainstay of interventions for acid-base imbalances
Assessment related to acid-base imbalance should include
a nursing history, physical assessment, fluid intake and output, daily weight, and laboratory studies, specifically the arterial blood gases
Conditions Respiratory Alkalosis
anxiety bacteremia fever hypoxemia pain pulmonary embolism
The PaCO² low
carbonic acid leaves the body in excessive amounts
Assessment Metabolic Acidosis
confusion drowsiness headache nausea/ vomiting resp. rate
Assessment Respiratory Acidosis
confusion lethargy nausea restlessness seizures shallow resp.
Treatment Metabolic Alkalosis
correct the cause restore fluid volume
Treatment Metabolic Acidosis
correct the defect may administer NaHCO3
Although compensation is the body's natural attempt to restore balance
correction may also be required
Conditions Metabolic Acidosis
diarrhea diabetic ketoacidosis renal insufficiency salicylate poisoning
Conditions Metabolic Alkalosis
diuretics gastric suction vomiting steroids
Causes Metabolic Alkalosis
gain of HCO3 or loss of H+
Causes Respiratory Alkalosis
hyperventilation
Causes Respiratory Acidosis
hypoventilation
The nursing assessment is directed toward the following:
identifying those at risk for acid-base imbalance Determine the specific imbalance through defining characteristics and assessment findings Determining plan of care, appropriate nursing diagnosis, followed by specific outcomes and associated interventions Evaluate the effectiveness of the plan of care
Assessment Respiratory Alkalosis
inability to concentrate lightheadedness loss of consciousness numbness and tingling resp. rate (increased)
Causes Metabolic Acidosis
loss of HCO3 or gain of H+
The kidneys are involved in either
reabsorbing bicarbonate or excreting bicarbonate, depending on what is needed to maintain the delicate acid-base balance
The PaCO² influenced by
respiratory activity
The bicarbonate level (HCO³ ) reflects
the bicarbonate level of the body
When the PaO² is low,
the hemoglobin carries less than normal amounts of oxygen
When the PaO² is high,
the hemoglobin carries more oxygen
Oxygen saturation readings (SaO² ) reveal
the percentage of oxygen in the blood that combines with hemoglobin
The PaCO² high
there are excessive amounts of carbonic acid in the body
Assessment Metabolic Alkalosis
tingling of fingers and toes neuromuscular irritability dizziness
Treatment Respiratory Alkalosis
treat cause rebreathe CO2: paper bag
Treatment Respiratory Acidosis
treat cause of hypoventilation
