Acid Base Balance

Etiologies: acute lung conditions that impair alveolar gas exchange, chronic lung disease, overdose of narcotics or sedatives, brain injury affects respirations, airway obstruction, mechanical injury.

*Acute manifestations (headache, warm skin, elevated pulse, blurred vision, irritable, altered mental status, decreasing LOC, cardiac arrest) *Chronic manifestations (weakness, dull headache, sleep disturbances, impaired memory, personality changes) *Therapies (frequently assess respiratory status and lung sounds, evaluate mental status, place in semi fowlers, encourage client to purse lip, monitor airway and ventilation ; insert artificial airway if necessary, administer pulmonary therapy measures such as inhalation therapy, monitor I&Os, vital signs, ABGs, administer narcotic as indicated)

Etiology: excessive acid losses due to vomiting or gastric suction, excessive use of potassium losing diuretics, excessive adrenal corticoid hormones due to cushings syndrome, hyperaldosterone, excessive bicarb intake from antacids, or parenteral sodium bicarb infusion.

*Manifestations (confusion, decreasing LOC, hyperreflexia, tetany, dysrhythmias, hypotension, seizures, respiratory failure) *Therapies (monitor I&Os, monitor vital signs especially respirations and LOC, administer ordered IV fluids carefully, administer oxygen as ordered, treat underlying problems).

Diagnosis

*Risk for impaired gas exchange is a priority problem *Deficient fluid volume *Risk for injury

Etiology: conditions that increase nonvolatile acids in the blood, conditions that decrease bicarb, excessive infusion of chloride containing IV fluids, excessive ingestion of acids, cardiac arrest.

*manifestations (diminished appetite, nausea, vomiting, abdominal pain, weakness, fatigue, headache, general malaise, decreasing LOCs, dysrhythmias, bradycardia, warm, flushed skin, skeletal problems, hyperventilation, dyspnea) *therapies (monitor ABG values, intake and output, LOC, position fowlers, provide oral care to dry mouth, administer IV sodium bicarb, treat underlying problem as ordered)

Etiologies: hyperventilation due to extreme anxiety, elevated body temp, over ventilation with a mechanical ventilator, hypoxia, saliclyate overdose, brain stem injury, fever, increased basal metabolic rate.

*manifestations (dizziness, numbness and tingling around mouth/hand/feet, palpitations, dyspnea, chest tightness, anxiety, panic, tremors, tetany, seizures, loss of consciousness) *therapies (monitor VS, LOC, and ABGs; encourage client to breath more slowly; administer sedative or anti anxiety as ordered; monitor ventilator settings; administer oxygen as ordered; maintain fluid status)

Diagnostic Tests

-ABGs a pH less than 7.35 and a PaCO2 of more than 45 mmHg. Acute respiratory acidosis bicarb is within normal range but increases greater than 28 mEq/L if condition persists. Chronic both the PaCO2 and the HCO3 elevated -Serum Electrolytes may show hypochloremia in chronic respiratory acidosis. -Pulmonary function tests done to determine whether chronic lung disease is the cause. -Additonal tests like chest X-ray, sputum studies.

Lab & Diagnostic Tests

-ABGs show pH greater than 7.45 and bicarb level greater than 28 mEq/L, hypoventilation CO2 is retained and the PaCO2 greater than 45 mmHg. -Serum Electrolytes decreased serum potassium <3.5 mEq/L and decreased chloride <95 mEq/L, total serum calcium may be normal the ionized fraction of calcium is low. -Urine pH may be low 1-3 if metabolic alkalosis is caused by hypokalemia, kidneys retain potassium and excrete hydrogen ion to restore ECF potassium levels. Urinary chloride levels may be normal or greater than 250 mEq/24 hours. -The ECG Pattern shows changes similar to those seen with hypokalemia.

cont... Excess metabolic acids increase the H ion concentration on body fluids. The buffering of excess acid by bicarb, leads to what is known as high anion gap acidosis. The pancreas secretes bicarb rich fluid into the small intestine. Intestinal suction, severe diarrhea, ileostomy drainage, or fistulas can lead to excess losses of bicarb. Hyperchloremic acidosis can develop when excess of a chloride solution is infuse, causing a rise in chloride concentrations. May be related to renal disease or administration of carbonic anhydrite inhibitor diuretics. Anion gap remains normal in metabolic acidosis due to bicarb loss or excess chloride.

-Acidosis depresses neuromuscular function. Increases the amount of free calcium in the ECF. Severe acidosis depresses myocardial contractility leading to decreased cardiac output. -Acidosis potassium is retained as the kidney excretes excess hydrogen ions. Excess H ions enter the cells displacing the potassium from the intracellular space to maintain the balance of cations and anions within the cells. Increases potassium levels. Magnesium may fall.

Risk Factors

-Acute lactic acidosis usually results from tissue hypoxia due to shock or cardiac arrest -clients with type 1 diabetes mellitus are at risk for developing diabetic ketoacidosis -acute or chronic renal failure impairs the excretion of metabolic acids -diarrhea, intestinal suction, or abdominal fistulas increase the risk for excess bicarb loss

Pathophysiology

-Acute pH rises rapidly as the PaCO2 falls. Because the kidneys are unable to adapt rapidly to the change in pH, the bicarb level remains within normal limits. Anxiety based hyperventilation is the most common cause of acute respiratory alkalosis. -Other physiological causes of hyperventilation include high fever, hypoxia, gram negative bacteremia, and thyrotoxicosis. -Early salicylate intoxication (aspirin overdose), encephalitis, and high progesterone levels in pregnancy lead to hyperventilation. -Also can occur during anesthesia and mechanical ventilation if the rate and tidal volume of ventilation are excessive. -If it continues, the kidneys compensate by eliminating bicarb to restore the ratio of bicarb to carbonic acid.As a result neuromuscular excitability increases and manifestations similar to hypocalcemia develop.

Clinical Manifestations

-Acute the rapid rise in PaCO2 levels causes headaches, blurred vision, irritability, and mental cloudiness. Conditon continues the LOC decrease. Rapid and dramatic changes in ABGs can lead to unconsciousness and potential lethal cardiac dysrhythmias. Skin will be warm and flushed and pulse elevated. Need emergency treatment. -Chronic include weakness and a dull headache. Sleep disturbances, daytime sleepiness, impaired memory, and personality changes. *hypoxemia often accompanies hypercapnia, requiring administration of supplemental oxygen.

Pharmacologic Therapy

-Alkalinizing solution such as bicarb may be given if the pH is less than 7.2, sodium bicarb most commonly used, others include lactate, citrate, and acetate solutions. May be given intravenously for severe acute metabolic acidosis. Chronic metabolic acidosis the oral route is used. -Carefully monitor treatment of bicarb. Rapid correction can lead to metabolic alkalosis and hypokalemia. Hypernatremia and hyperosmolality may develop as well leading to water retention and fluid overload. *As metabolic acidosis is corrected, potassium shifts back into the intracellular space. This shift can lead to hypokalemia and cardiac dysrhythmias. Carefully monitor serum potassium levels during treatment. -Treatment for diabetic ketoacidosis includes intravenous insulin and fluid replacement. Treated with saline solution and glucose.

Diagnostic Tests: Pg. 11 interpreting ABG's ABGs evaluate the clients acid base balance and oxygenation. Examiner must perform an Allen test before drawing ABGs. May be drawn by respiratory therapists, healthcare providers, or nurses with specialized skills. Because blood drawn from a high pressure artery, important to apply pressure to the puncture site for 10 minutes if client is receiving anticoagulants after the procedure to reduce risk of bleeding or bruising.

-Analyze ABGs by first evaluating individual measurements; then analyze the interrelationships to determine the clients acid base balance -Allen test is a measurement of radial or ulnar patency; examiner digitally compresses either the radial or the ulnar artery after the client has forced the blood out the hand by clenching in into a fist. Failure of the blood to diffuse into the hand when it is opened indicates occlusion of whichever artery was not compressed. In such case, circulation is inadequate and no ABG is drawn.

Metabolic Acidosis Exemplar Overview

-Bicarb deficit -Characterized by low pH <7.35 and a low bicarb <24 mEq/L! -Caused by excess acid in the body or loss of bicarb from the body. -Respiratory system attempts to return the pH to normal by increasing the rate and depth of respirations, CO2 elimination increases, and the PaCO2 falls below 35 mmHg.

Metabolic Alkalosis Exemplar Overview

-Bicarb excess -high pH (>7.45) and high bicarb (>28 mEq/L) -caused by a loss of acid or excess bicarb in the body -respiratory system attempts to return pH to normal by slowing the respiratory rate CO2 is retained and the PaCO2 increases 45 mmHg

1. BUFFER SYSTEM -Buffers are substances that prevent major changes in pH by releasing hydrogen ions. When excess acid is present in body fluid, buffers bind with hydrogen ions to minimize the change in pH. If body fluids become to basic or alkaline buffers release H ions restoring the pH. -Bodys major buffer systems are bicarbonate carbonic acid buffer systems, phosphate buffer system, and protein buffers. -Normal serum bicarbonate level is 24-28 mEq/L; carbonic acid is 1.2 mEq/L ratio of bicarb to carbonic is 20:1; as long as this ratio is maintained the pH remains within normal range.

-Bicarbonate (HCO3) is a weak base when an acid is added to the system the hydrogen ion in the acid combines with bicarb an pH changes slightly. Carbonic acid (H2CO3) is a weak acid produced when CO2 dissolves in water when a base is added to the system it combines with carbonic acid and pH remains normal. -Adding a strong acid to extracellular fluid depletes bicarbonate and pH drops below 7.35 this is known as acidosis -Adding a strong base depletes carbonic acid as it combines with the base, pH rises above 7.45 a condition known as alkalosis.

Pharmacologic Therapy

-Bronchodilator open airways -Antibiotics to treat infections -Narcotic antagonists such as naloxone to reverse effects or narcotics.

Respiratory Alkalosis Exemplar Overview

-Characterized by a pH greater than 7.45 and a PaCO2 of less than 35 mmHg. -Always caused by hyperventilation (unusually fast respirations, or over breathing) leading to CO2 deficit.

Evaluation

-Client experiences no subsequent episodes of hyperventilation. -Client describes strategies for coping with anxiety in the future. -Family displays ability to contribute to calming the client during times of anxiety. -Client and/or family participate in support groups that will help client cope with anxiety.

Planning

-Client will describe and demonstrate preventive measures related to chronic disease process -pH will remain within normal range -Disease process causing acid base imbalance will be controlled to reduce acid production or alkaline loss -Client will maintain vital signs within normal range for age and condition -Client will maintain baseline cardiac rhythm -Client will maintain or regain normal serum electrolyte levels

Diagnosis

-Decreased cardiac output -Risk for excess fluid volume -Risk for injury

Assessment

-Health history [anxiety disorders; triggering event for the onset of hyperventilation; mental health disorders, coping mechanisms; support systems available] -Physical assessment [breath sounds; neurological function; respiratory and cardiac status; any changes in LOC]

Assessment

-Health history [current manifestations, duration of symptoms and any precipitating factors such as drug use or respiratory infections or chronic diseases, current meds] -Physical Exam [mental status and LOC; VS; skin color and temp; rate and depth of respirations, pulmonary excursion, and lung sounds]

Assessment

-Health history [manifestations such as numbness and tingling, muscle spasms, dizziness, or other; duration of symptoms and any precipitating factors such as bicarb ingestion, vomiting, diuretic therapy, or endocrine disorders; current meds] -Physical assessment [vital signs, apical pulse and rate and depth of respirations; muscle strength; deep tendon reflexes] -Diagnostic tests [ABGs, serum electrolytes]

Assessment

-Health history [want to find underlying cause of imbalance, each disorder has specific symptoms, identify the prescribed and OTC meds that client is taking, complementary therapies such as vitamins and herbs] -Physical assessment [VS are taken, including pulse oxiemtry, correlate the results of the pulse oximeter with ABG results]

Diagnosis

-Impaired Gas Exchange -Ineffective Airway Clearance -Anxiety -Risk for injury

Pharmacologic Therapy -Careful monitoring of ABG levels prevents over treatment that causes pH to alter in the opposite direction. -Acidosis clients goal is to reverse the effects of acids in the blood and return client to normal pH levels as quickly as possible, treatment of choice is sodium bicarbonate infusions, provided that the bicarb level is low. Bicarb ion acts as a base to neutralize acids in the blood and other fluids. Carefully monitor the clients ABGs during infusions and watch for signs of alkalosis; this drug can overcorrect the acidosis, causing blood pH to turn alkaline. (Symptoms of alkalosis are irritability, confusion, cyanosis, slow respirations, irregular pulse, and muscle weakness). -Nurse role in sodium bicarb therapy involves carefully monitoring a clients condition and educating the client and family about the treatment. Given to neutralize acidotic states; first analyze the ABG reports of pH, PaCO2, HCO3, PaO2 and O2 saturation. Assess clients for acidosis symptoms (sleepiness, coma, disorientation, dizziness, headache, seizures, hypoventilation). Also look for causative factors that could produce acidosis like diarrhea, shock, and diabetes.

-Monitor sodium bicarb carefully in clients with cardiac and renal problems. -Sodium bicarb used to alkalinize the urine and speed the excretion of acidic, process useful in treating overdoses of certain acidic meds such as aspirin and phenobarbital, also used in chronic renal failure to neutralize the metabolic acidosis that occurs when the kidneys cannot excrete hydrogen ion. Intravenous sodium bicarb causes the urine to become more alkaline. Less acid is reabsorbed in the renal tubules, so more acid and acidic medicine is excreted. This is known as ion trapping. -Sodium bicarb (baking soda) is used at home to neutralize gastric acid, relieving heartburn and sour stomach. Nurses should be aware clients may misinterpret cardiac symptoms as heartburn, and overuse of sodium bicarb may lead to alkalosis.

3. RENAL SYSTEM -Responsible for long term regulation of acid base balance, kidneys normally eliminate excess nonvolatile acids produced during metabolism, also regulate bicarb levels in the ECF by regenerating or reabsorbing bicarb ions in the renal tubules. -Kidneys respond more slowly to change in pH (over hours to days), they can generate bicarb and selectively excrete or retain H ions as needed. -Acidosis excess H ions are present the pH falls, the kidneys excrete H ions and retain bicarb. -Alkalosis kidneys retain H ions and excrete bicarb to restore balance. -PaCO2 (35-45 mmHg) measures the pressure exerted by dissolved CO2 in the blood and reflects the respiratory component of acid base regulation and balance because it is regulated by the lungs. Less than 35 is hypocapnia; greater than 45 is hypercapnia.

-PaO2 (75-100 mmHg) is a measure of the pressure exerted by oxygen that is dissolved in the plasma. Less than 80 mmHg indicates hypoxemia. Valuable for evaluating respiratory function, but not used as primary measurement in determining acid base status. -Serum bicarbonate (24-28 mEq/L) reflects the renal function of acid base balance. -Base excess (BE) (+2 to -2 mEq/L) calculated value also known as buffer base capacity. Measures substances that can accept or combine with hydrogen ions. Reflects the degree of acid base imbalance by indicating the status of the body's total buffering capacity. Represents the amount of acid or base that must be added to a blood sample to achieve a pH of 7.4 and is essentially a measure of increased or decreased bicarb. -Acid base balance is assessed primarily by measuring arterial blood gases (ABGs). It reflects acid base balance throughout the entire body better than venous or capillary blood that has dispersed oxygen into the tissues and has collected CO2. Also provides info about the effectiveness of the lungs in oxygenating blood.

2. RESPIRATORY SYSTEM -Regulates carbonic acid by eliminating or retaining CO2, it is a potential acid; when combined with water, it forms carbonic acid, a volatile acid. -Acute increases in CO2 or H ions in the blood stimulate the brains respiratory center, increasing both the rate and depth of respiration. CO2 is eliminated and carbonic acid levels fall, bringing pH to normal range.

-This compensation for increased H ions concentration occurs within minutes, it becomes less effective over time. Ex: COPD may have consistent high CO2 levels in their blood -Alkalosis depresses the respiratory center decreasing both the rate and depth of respirations and causing CO2 retention, it then combines with water to restore carbonic acid levels and bring the pH back within normal range

Chronic Respiratory Acidosis -chronic respirations or neuromuscular conditions such as COPD, asthma, cystic fibrosis, and MS. Affect alveolar ventilation because of airway obstruction, structural changes in the lung, and limited chest wall expansion. -PaCO2 increases over time and remains elevated, kidneys retain bicarb, increasing bicarb levels, and the pH remains close to the normal range because of adequate metabolic compensation.

-acute effects of hypercapnia may not develop when CO2 levels rise gradually, allowing compensatory changes. When CO2 levels are chronic elevated, the respiratory center becomes less sensitive to the gas as a stimulant of the respiratory drive. PaO2 provides the stimulus for respirations. -Risk for developing CO2 narcosis if the respiratory center is depressed by the administration of excess supplemental oxygen. Manifestations include confusion, tremors, and convulsions; coma can occur if blood levels of CO2 reach 70 mmHg or higher. *Carefully monitor neurological and respiratory status in clients with chronic respiratory acidosis who are receiving oxygen therapy. Immediatley report decreasing LOC or depressed respirations.

Risk Factors

-acute/chronic lung disease -trauma to lungs -excess narcotic analgesics -airway obstruction -neuromuscular disease

Planning

-adequate fluid intake -oxygenation saturation greater than 90% -normal PaCO2 levels -pH balance

Risk Factors

-anxiety with hyperventilation! -client critically ill, mechanical ventilation.

Monitor for Fluid Volume Deficit

-assess I&Os accurately, monitoring for balance. Less than 30 mL/hour indicates inadequate tissue perfusion, renal perfusion, and an increased risk for renal failure. -assess vital signs, CVP, and peripheral pulse volume at least every four hours. Hypotension, tachycardia, low CVP, and weak, easily obliterated peripheral pulses indicate hypovolemia. -weigh daily under same conditions, rapid weight changes show fluid balance -administer intravenous fluids as prescribed on electric infusion pump, monitor for fluid overload, dyspnea, tachypnea, tachycardia, increased CVP, jugular vein distention, and edema. Can lead to pulmonary edema and cardiac failure. -monitor serum electrolytes, osmolality, and ABG values

Reduce Risk for Injury

-assess LOC, mental status, orientation frequently -place call bell within reach -manage rest and activity patterns to reduce oxygen demands -administer supplemental oxygen as needed to prevent hypoxia or tissue damage

Evaluation

-client maintains pH within normal range -clients vital signs remain within normal range based on the age and condition -client maintains adequate oxygenation of tissues -client is able to describe or demonstrate measures to control the disease process to prevent future complications of pH imbalance.

Evaluation

-client maintains patent airway -client maintains appropriate breathing patterns to meet oxygen demands -client remains conscious and does not display anxiety indicating potential hypoxia -ABG reflects pH and PaCO2 within an acceptable range for the client.

Risk Factors

-critically ill clients -metabolic acidosis occurs in clients with insulin dependent diabetes mellitus and chronic renal failure, or from severe diarrhea at any age -metabolic alkalosis occurs in clients in acute care, older adults at risk because of fragile F&E status -clients at all ages at risk for respiratory acidosis when alveolar hypoventilation occurs, clients with COPD at highest risk -older adults and young children are at risk for respiratory alkalosis with large doses of salicylate ingestion,

Independent Interventions

-daily weight -monitoring I&Os -assessing respiratory and renal function -patent airway -monitor oxygen saturation -taking vital signs -assess LOC and neurological function -prompt reporting or any changes

Respiratory Acidosis Exemplar Overview

-excess CO2 -characterized by pH less than 7.35 and a PaCO2 greater than 45 mmHg -can be acute or chronic -chronic respiratory acidosis bicarb is higher than 26 mEq/L as the kidneys compensate by retaining bicarb

Promote Effective Airway Clearance

-frequently auscultate breath sounds, increasing adventious sounds or decreasing breath sounds may indicate worsening airway clearance -encourage client with chronic to use pursed lip breathing helps maintain open airways promoting CO2 elimination -frequently reposition and encourage ambulation as tolerated promotes clearance and lung expansion -encourage fluid intake -administers meds like bronchodilators as ordered -provide percussion, vibration, and postural drainage as ordered

Clinical Manifestations

-general manifestations are weakness, fatigue, headache, general malaise -GI function cause diminished appetite, nausea, vomiting, abdominal pain -LOC may decline into stupor or coma -Cardiac dysrhythmias develop, and cardiac arrest may occur -Skin warm and flushed -Skeletal problems may develop -Kussmaul respirations (deep and rapid respirations) -SOB or dyspnea

Client teaching Sodium Bicarb

-immediately contact doctor if gastric discomfort continues or is accompanied by chest pain, dyspnea, or diaphoresis -use non sodium antacid to prevent the absorption of excess sodium of bicarb into the systemic circulation -do not use any antacid, including sodium bicarb, for longer than 2 weeks without consulting doctor

Diagnosis

-ineffective breathing pattern -anxiety -risk for injury

Clinical Manifestations

-light headiness, feeling of panic and difficulty concentrating, circumoral and distal extremity paresthesias (numbness or tingling), tremors, and positive chvostek sign (type of facial spasm), and trousseau sign (a spasm of the hand and forearm), tinnitus, chest tightness, and palpations, seizures, loss of consciousness.

Planning

-manifest normal respiratory rate and rhythm -maintain safety -maintain appropriate fluid status

Monitor Cardiac Status

-monitor VS peripheral pulses and cap refill, poor tissue perfusion can increase the risk for lactic acidosis. -monitor the ECG pattern for dysrhythmias and changes of characteristics of hyperkalemia -monitor lab values including ABGs and serum electrolytes and renal function. *Administrering bicarb to correct acidosis increases the risk for hypernatremia, hyperosmolality, and fluid volume excess.

Monitor Potential for Excess Fluid Volume

-monitor and maintain fluid replacement as ordered -monitor heart and lung sounds, central venous pressure, and respiratory status. -assess for edema -assess urine output hourly, heart failure and inadequate renal perfusion may lead to decreased urine output -obtain daily weights using consistent conditions -administer prescribed diuretics as ordered, monitoring the clients response to therapy

Reduce Risk for Injury

-monitor neurological function, including mental status, LOC, and muscle strength. As the pH falls leads to confusion. -institute safety precautions as necessary -keep clocks, calendars, and familiar objects at bedside. always try to orientate to time, place, and circumstance.

Monitor for Impaired Gas Exchange: Respiratory compensation for metabolic alkalosis depresses the respiratory rate and reduces the depth of breathing to promote CO2 retention. Client at risk for impaired gas exchange.

-monitor respiratory rate, depth, and effort. oxygen saturation continuously, report less than 93%. lead to hypoxemia and impaired oxygenation of tissues. -assess skin color; note and report cyanosis around the mouth. around the mouth indicates significant hypoxia and late sign. -monitor mental status and LOC, report decreasing LOC such as restlessness, agitation, or confusion these are early signs of hypoxia. -place in semi fowlers helps facilitate ventilation -administer oxygen as ordered to maintain oxygen saturation levels -schedule nursing activities to allow rest periods

Promote Gas Exchange

-promptly evaluate and report ABG results to the doctor and respiratory therapist -place in semi fowlers -administer oxygen as ordered and monitor response

Concept of Acid-Base Balance -Critical to homeostasis & optimal cellular function -hydrogen ion concentration of body fluids must be kept within narrow range -hydrogen ions determine the relative acidity of body fluids -Acids release hydrogen ions in solution -Bases (or alkalis) accept hydrogen ions into solutions -Hydrogen ion concentration of a solution is measured as its pH normal ranges are 7.35-7.45. (7 is neutral). Normal pH indicates acid base balance.

-relationship between hydrogen ion concentration and pH is inverse; as H ion increases, the pH falls, and the solution becomes more acidic; as H ion falls, the pH rises, and the solution becomes alkaline or basic. -imbalance results from any one of several underlying causes and can be important clue in diagnosing illness or disease -failure to restore balance can lead to impairment of organs and critical bodily functions vary narrow tolerance for alterations in acid base levels

Reduce Anxiety Levels

-remain with client and monitor for changes -explain procedures and treatments using short simple sentences -reduce environmental stimuli and use a calm manner -allow supportive family to remain with client

Pharmacologic Therapy

-restoring normal fluid volume and administering potassium chloride and sodium chloride solution -potassium restores serum and intracellular potassium levels, allowing the kidneys to conserve more H ions more effectively -chloride promotes renal excretion of bicarb -sodium chloride solutions restore fluid volume deficits -severe alkalosis, acidifying solution such as dilute hydrochloric acid or ammonium chloride may be administered.

Pharmacologic Therapy

-sedative -antianxiety agent to relieve anxiety and restore normal breathing

Acute Respiratory Acidosis

-sudden failure of ventilation -chest trauma, aspiration of foreign body, acute pneumonia, overdoses of narcotic or sedative meds -PaCO2 rises rapidly and the pH falls markedly, a pH of 7 or lower can occur within minutes resulting in death if not treated. -initally serum bicarb level unchanged because kidneys take longer to compensate -hypercapnia (increased CO2 levels) affect neurological function and the cardiovascular system, CO2 crosses the blood brain barrier; cerebral blood vessels dilate and if continues causes intracranial pressure and papilledema (swelling and inflammation of the optic nerve where it enters the retina). Pulse rate increases!

Acid-base imbalances fall into two major categories:

1.Acidosis 2.Alkalosis *Acid base balance affect other concepts/body systems Pg.5

Alterations & Manifestations: Pg. 8-10 look at charts! -Further classified as metabolic or respiratory disorders 1. metabolic disorders (primary change is in the concentration of bicarb, bicarb decreases in relation to the amount of acid in the body).. *Metabolic Acidosis develop from abnormal bicarb losses or from excess nonvolatile acids in the body. pH falls below 7.35, bicarb is less than 24 mEq/L. *Metabolic Alkalosis develops when there is an excess of bicarb in relation to H ions, pH is above 7.45, and bicarb greater than 28 mEq/L.

2. Respiratory disorders (primary change is in the concentration of carbonic acid) *Respiratory Acidosis occurs when CO2 is retained, increasing the amount of carbonic acid in the body, pH falls below 7.35 and the PaCO2 is greater than 45 mmHg. Any condition causing hypoventilation can lead to this. *Respiratory Alkalosis occurs when to much CO2 is lost, carbonic acid levels fall, pH rises above 7.45, and the PaCO2 is less than 35 mmHg. Any condition causing hyperventilation can lead to this. -Acid base imbalances can be further defined as primary (simple) or mixed. *Primary disorders have one cause. Example respiratory failure causing respiratory acidosis due to retained CO2. *Mixed disorders occur from combinations of respiratory and metabolic disturbances.

Pathophysiology & Etiology *Three basic mechanisms can cause metabolic acidosis: 1. Accumulation of metabolic acidosis 2. Excess loss of bicarb 3. an increase in chloride levels

Accumulation can occur from excess acid production or impaired renal elimination of metabolic acids. Lactic acidosis develops due to tissue hypoxia and a shift of anaerobic metabolism by the cells. Lactate and hydrogen ions are produced, forming lactic acid. Both oxygen and glucose are necessary for normal cell metabolism. When intracellular glucose is inadequate due to starvation or a lack of insulin to move into the cells, the body breaks down fatty tissue to meet its metabolic needs. In this process fatty acids are released and converted to ketones; ketoacidosis results. Aspirin breaks down into salicylic acid in the body. Substances such as aspirin, methanol, and ethylene cause a toxic increase in body acids by either breaking down into acid products or stimulating metabolic acid production. Renal failure impairs the body's ability to excrete excess hydrogen ions and form bicarb.

Collaboration

Aimed at controlling alkalosis while treating underlying cause with healthcare team!

Pathophysiology

Both acute and chronic result from CO2 retention caused by alveolar hypoventilation. Hypoxemia (decreased oxygen) frequently accompanies respiratory acidosis.

Compensation

Compensatory changes in other parts of the regulatory system occur to restore a normal pH and homeostasis. -Metabolic acid base disorders, the change in pH affects the rate and depth of respirations, which, in turn, affect CO2 elimination and the PaCO2 and helps restore the ratio of carbonic acid to bicarb. Kidneys compensate for simple respiratory imbalances. -pH is restored to within normal limits the disorder is said to be fully compensated -pH remains outside normal limits the disorder is said to be partially compensated

Care in the Community

Consider the cause and any underlying factors. -using appropriate antacids for heartburn and gastric distress -using potassium supplements as ordered or eating high potassium foods to prevent hypokalemia if taking potassium wasting diuretics or if aldosterone production is impaired -contacting doctor if uncontrolled or extended vomiting develops

Collaboration

Correcting the imbalance and treating the cause. Important to create a calm, quiet, low stimulant environment to reduce the clients anxiety or panic. ABGs must be ordered prior to administration of medications or oxygen therapy.

Planning

Depends on identification and treatment of underlying cause. Restoring and maintaining normal acid base balance is desired outcome. -oxygen saturation level of 93% or greater -normal or near normal fluid and electrolyte volumes

Care in the Community

Discharge focus on the underlying cause of the imbalance and teaching the client. -use appropriate resources to get medical assistance -contacting primary care provider

Collaboration

Efforts of entire healthcare team, respiratory therapist to provide breathing treatments and related therapies, consult with pharmacist, and primary doctor to check meds being administered that may be contradicted. Using accessory muscles to breath may require increase caloric intake so dietician.

Pathophysiology: H ions may be lost through the kidneys or via gastric secretions or because of a shift of H ions into the cells. Metabolic alkalosis due to loss of H ions usually occurs because of vomiting or gastric suction. Gastric secretions are highly acidic pH 1-3. When these are lost through vomiting or suctioning, the alkalinity of body fluids increase. Increase in alkaline is from the loss of acid and from selective retention of bicarb by the kidneys as chloride is depleted. When chloride lost bicarb is retained. Increased renal excretion of H ions can be prompted by hypokalemia as the kidneys try to conserve potassium, excreting H ions instead. When potassium shifts out the cells to maintain extracellular potassium levels, H ions shift into the cells to maintain the balance between cations and anions within the cells.

Excess bicarb usually occurs as a result of ingesting antacids that contain bicarb or overzealous administration of bicarb to treat metabolic acidosis. In alkalosis more calcium combines with serum proteins, reducing the amount of ionized calcium in the blood. This reduction in ionized calcium accounts for many of the common manifestations of metabolic alkalosis. Affects potassium balance: Hypokalemia not only can cause metabolic alkalosis, but also can result from metabolic alkalosis. Hydrogen ions shift out of the intracellular space to help restore the pH, prompting more potassium to enter the cells and depleting ECF potassium. High pH depresses the respiratory system as the body retains CO2 to restore the ratio of carbonic acid to bicarb.

Nursing Process

Focus of care is underlying problem rather than the acidosis. Be aware of effects of acidosis and its implications for nursing care. Discuss management of the underlying disease process to help prevent complications such as diabetic ketoacidosis and metabolic acidosis. Early manifestations resemble common viral disorders such as flu stress the importance of seeking treatment.

Nursing Process

Focus on teaching clients the risks of using sodium bicarb as an antacid to relieve heartburn or gastric distress. Stress the availability of other effective antacid preparations and the need to seek medical help if persistent gastric symptoms. Monitor lab values for clients at risk for metabolic alkalosis especially those getting gastric suctioning.

Implementation

Focused on controlling pH while treating the underlying causative disorder and preventing complications.

Respiratory Support

Focuses on improving alveolar ventilation and gas exchange. Clients with severe acidosis and hypoxemia may require intubation and mechanical ventilation. The PaCO2 level is lowered slowly to prevent complications such as cardiac dysrhythmias and decreased cerebral perfusion. Oxygen administers cautiously to prevent CO2 narcosis. Pulmonary hygiene measures may be instituted such as deep breathing and coughing, breathing treatments, and percussion and drainage. Adequate hydration to loosen secretions.

Implementation

Frequently assess respiratory status, including rate, depth, effort, and oxygen saturation levels. Decreasing respirations may signal worsening respiratory failure and acidosis. *Frequently asses LOC. A decline in LOC may indicate hypercapnia and the need for increasing ventilatory support such as intubation.

Assessment

Health History [current manifestations, diminished appetite, nausea, vomiting, abdominal discomfort, fatigue, lethargy, and other symptoms; duration of symptoms and any factors such as diarrhea and ingestion of a toxin; chronic diseases; current meds] Physical assessment [mental status, LOC, vital signs, respiratory rate and depth, apical and peripheral pulses, skin color and temp, abdominal contour and distention, bowel sounds, urine output]

Nursing Process

Improving breathing patterns and maintaining a patent airway. Teaching clients healthier lifestyle choices like stop smoking!

Lifespan & Cultural Considerations

Infants & Children: -high risk for fluid and electrolyte imbalance because of their immature kidneys, which cannot concentrate urine -infants have rapid respiratory rates, lead to insensible losses, and they cannot actively seek fluid Older Adults: -high risk for F&E imbalance because of the decreased ability of their kidneys to concentrate urine, their decreased thirst sensation, and decreased levels of intracellular fluid. -older adults have more comorbidities such as hypertension, heart disease, renal failure, and dementia.

Implementation

Metabolic acidosis affects cardiac output by decreasing myocardial contractility; slowing the heart rate, and increasing the risk for dysrhythmias. soooo....

Normal Acid-Base Balance

Metabolic processes in the body continuously produce acids, which fall into two categories: 1. Volatile Acids [eliminated from the body as a gas, carbonic acid (H2CO3) is only volatile acid produced in the body. It dissociates into carbon dioxide and water, and the lungs eliminate the CO2] 2. Nonvolatile Acids [all other acids produced in the body must be metabolized or excreted in fluid, lactic acid, hydrochloric acid, phosphoric acid, sulfuric acids] *Three systems work together to maintain pH within normal range:buffer system, respiratory systems, and the renal system

Risk Factors

Occurs as a primary disorder. Risks include hospitalization, hypokalemia, and treatment with alkalinizing solutions.

Care in the Community

Planning and teaching home care focus on the problem that caused the respiratory acidosis! -teach preventive measures and equipment that can be used at home -if acute acidosis from narcotics determine whether drug was prescribed for pain or a street drug, provide teaching about the drug, refer client to illicit drugs to a substance abuse counselor, treatment center, or narcotics anonymous -chronic lungs problems discuss ways to avoid future problems encourage flu immunizations and ways to prevent infection -measures to take when respiratory problems do come about like symptoms that are bad and what to do.

Nursing Process

Reducing the anxiety through manipulation of the environment to reduce stimuli and to create a sense of peace! Restful environment helps client breath more slow and effectively.

Airway Management

Respiratory distress may require intubation. Generally intubation is indicated if the client has a PaCO2 greater than 77 mmHg, PaO2 less than 60 mmHg, and a pH less than 7.20. Clients with chronic hypercarbia require care to correct their status slowly, as correcting PaCO2 to quickly may result in metabolic alkalosis.

Evaluation

Restoring normal body balance! -Client reports use of antacids that are acceptable for use and reduce the risk of recurrence of metabolic alkalosis. -Client prescribes proper self administration procedure for oral potassium supplements. -Client describes when to notify doctor related to daily weight changes. -Clients arterial pH returns to normal range. -Clients serum electrolyte values return to normal.

Clinical Manifestations

Result from decreased calcium ionization and are similar to hypocalcemia. -numbness and tingling around the mouth, fingers, and toes; dizziness; trousseaus sign; and muscle spasm. Respirations are depressed and respiratory failure with hypoxemia and respiratory acidosis may develop.

Collaborative

Taking VS and taking a thorough client history, which includes risk factors, cardiac, renal, pulmonary, current meds, medical conditions, and symptoms. Family members may need to be consulted for critical info. Healthcare team collaboration!

Collaboration

Treating primary disorder, reducing the affects of acidosis on cardiac function, and insuring adequate oxygenation.

Respiratory Therapy

Use of paper bags helps to raise CO2 levels in clients with true hyperventilation syndrome, it can also cause hypoxia. Other diseases can mimic hyperventilation like myocardial infarction, and hypoxia induced by the use of paper bag will cause further cellular damage. Elevated CO2 levels have been found to trigger panic attacks, which further exacerbate hyperventilation. Best treatment is to teach breathing exercises.

Implementation

Usual cause is psychological, it is important not only to address the hyperventilation but also to identify the cause. -assess respiratory rate, depth, and ease. monitor VS and skin color. -obtain subjective data such as circumstances leading up to the current situation, current health and recent illnesses or med use, and current symptoms. -reassure client the symptoms do not indicate heart attack and that will resolve when breathing returns to normal -instruct client to maintain eye contact and breath with you to slow the rate -protect the client from injury -refer to counseling who have repeated episodes or anxiety disorders