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Click for Practice ABG Interpration table

• Scale Range 0 - 14
• 7= Neutral < 7= acid [hydrogen ion donor] > 7= alkaline [hydrogen ion taker]
• Normal pH 7.35 - 7.45 - The normal pH of extra cellular fluid (EC.) is sightly alkaline
• pH < 7.35 - ACIDOSIS - Increased hydrogen ions
• pH > 7.45 - ALKALOSIS - Decreased hydrogen ions

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UNBALANCED RELATIONSHIP

I. ACIDOSIS

Neurologic dysfunction is an early indicator

1. Lethargy
2. Confusion
3. Disorientation
4. Headache
5. Muscle twitching
6. Stupor
7. Coma

Key Point: In acidosis, both pH and CNS function are depressed

II. ALKALOSIS

pH > 7.45 causes over excitability of CNS and produces:

• Tingling of extremities
• Nervousness and irritability
• Seizures

BASE as mnemonic:

• B = Base pH
• A = Above normal pH (>7.45) produces
• S = Spasms
• E = Excitability

Key Concepts:

• pH is a measure of hydrogen ion concentration
• pH < 7 is acid
• pH > 7 is alkaline
• Normal pH of EC. is 7.35 to 7.45 5. Acids are able to give up hydrogen ions
• Bases are able to accept hydrogen ions
• This ability (5 & 6) allows the body to maintain acid-base balance
• Alkalosis is a condition in which the pH of ECF is increased and the hydrogen ion concentration is decreased
• Acidosis is a condition in which the pH of ECF is decreased and the hydrogen ion concentration is increased
• Both acidosis and alkalosis affect the functioning of the nervous system

• ACIDOSIS - produces symptoms of CNS depression
• ALKALOSIS - produces symptoms of CNS excitement

The body has (3) defense or Regulatory Systems it used to keep the pH 7.35 to 7.45:

I. The Chemical Buffer System

a. Buffers are chemical substances that act immediately (within 0.1 seconds) to reduce the impact of any drastic change in pH

b. This is accomplished by Buffers releasing or absorbing hydrogen ions

c. Buffers can combine with either an acid or base

d. Primary buffer system in the body is the Bicarbonate-Carbonic Acid System (responsible for ~80% of buffering that occurs in ECF)

e. This buffer consists of a mixture of carbonic acid (H2CO3) and bicarbonate (HCO3)

H2CO3 is a weak acid that dissociates into hydrogen ions and bicarbonate ions that are excreted by the kidneys and H2O and carbon dioxide that are excreted by the lungs

When bicarbonate-carbonic buffer system neutralizes either a strong acid or a strong base the end products are excreted by the kidney and lungs

Normally to maintain acid-base balance

• pH 7.35 - 7.45 the ratio of HCO3 to H2CO3 is 20:1
• HCO3 = 20 = pH 7.40 H2CO3 = 1

II. RESPIRATORY SYSTEM

Carbon Dioxide (CO2) that we exhale comes from carbonic acid (H2CO3)

• The normal range of arterial CO2 is 38-42
• The respiratory center in the medulla is sensitive to hydrogen ion concentration and acts as a feed back system for controlling hydrogen ion concentration
• When hydrogen ion concentration in ECF increases the medulla (brain stem) directs the respiratory system to increase the rate and depth of respirations to "Blow Off" more CO2 (hyperventilation)
• Hyperventilation decreases the concentration of CO2 in the ECF and decreases CO2 available to combine with H2O to form H2CO3 NOTE: Thus arterial pH does not change precipitously with an increase in hydrogen ions
• When hydrogen ions concentration in the ECF decreases, the medulla directs the respiratory center to decrease the rate and depth of respirations to retain CO2 (hypoventilation)
• Hypoventilation increases the concentration of CO2 in ECF - more CO2 is now available to combine with H2O to form H2CO3. Thus the pH does not change precipitously
• The respiratory system responds to changes in pH within 1-2 minutes
• The respiratory system cannot completely correct acid-base imbalances (50% - 70% effective)

III. RENAL SYSTEM

• Also responsible for maintaining normal pH and hydrogen ion concentration
• Is the slowest acting of the adaptive systems - takes from several hours to several days
• HOWEVER the renal system is the most powerful
• Continues to act until pH returns to normal range
• Kidneys regulate pH balance through a complex process
• Kidneys form and retain HCO3 ions in amounts determine by the blood pH
• This process takes place in the renal tubules NORMAL range of HCO3 is 24 - 28

When blood pH decreases (becomes more acidotic) the kidneys respond by excreting hydrogen ions and forming and retaining bicarbonate ions

• When blood pH increases (becomes more alkalotic) the kidneys respond by retaining hydrogen ions and excrete more bicarbonate ions ie:
• During normal metabolism the body produces excess acids.
• To maintain acid-base balance the kidneys must excrete excess hydrogen ions via the urine.
• This explains why normal urine has a pH that is usually acid To maintain acid-base balance the ratio of base bicarbonate to carbonic acid is 20:1

COMPENSATION:

Occurs when plasma pH changes the buffers

• Respiratory system
• Renal system

React together to return the plasma pH to normal by restoring the 20:1 ratio of bicarbonate (HCO3) to carbonic acid (H2CO3)

• Metabolic Disorders are compensated for by the Respiratory System

• Respiratory Disorders are compensated for by the Kidneys

Key Concepts with Compensation:

• Metabolic acid-base imbalances are compensated by respiratory system
• Respiratory acid-base imbalances are compensated by the metabolic system
• Any change in the PCO2 reflect respiratory change
• Any change in the HCO3 reflect metabolic change
• Compensation has occurred when pH has returned to normal range
• Compensation is not always total. It may be partial in which case the pH will remain slightly decreased or slightly increased

CAUSES OF ACID-BASE INBALANCES:

• Metabolic disturbances:
• metabolic acidosis and alkalosis are brought about by changes in bicarbonate (base levels resulting in metabolic alterations

• Respriatory disturbances:
• respiratory acidosis and alkalosis are brought about by changes in carbonic acid (H2CO3) levels resulting from respiratory alterations

Changes in both pH and PCo2 occur

No Change in HCO3 occurs

Respiratory Acidosis

• Ph decreases
• PCO2 increases

Respiratory Alkalosis

• Ph increases
• PCO2 decreases

UPPER AIRWAY DISORDERS (on your own)

• Rhinitis ( common cold )
• Sinusitis
• Pharyngitis
• Tonsillitis
• Epistaxis
• Carcinoma of Larynx
• **Laryngectomy

LOWER AIRWAY DISORDERS:

Risk Factors

Categories of Pulmonary Disorders

• Infections - Restrictive Disorders: Pneumonia/ Tuberculosis
• Restrictive Disorders - Sarcoidosis/Lung Cancer
• Obstructive Disorders - Asthma /Chronic Bronchitis /Emphysema
• Pulmonary Vascular Disorders - ARDS/Pulmonary Embolism

PROBLEMS OF THE LOWER AIRWAY:

Statistics:

• Decreased number of deaths related to cute and chronic respiratory infections due to antibiotics
• Increase in tuberculosis over the last ten years, especially the last 4 years due to AIDS/HIV
• More people living with COPD (> 17 million)
• Increased incidence of lung cancer, especially among women
• Increased number of teenagers starting to smoke
• PNEUMONIA IS THE LEADING CAUSE OF DEATH BY INFECTIOUS DISEASE IN THE U.S.

PREVENTION:

• Education of the Public/Advocacy for healthy, smoke-free environment (The use of tobacco clearly is the #1 risk to developing COPD and lung cancer)
• Most people start smoking before high-school graduation
• Nicotine addition results in withdrawal symptoms
• Smoking is tied to alcohol consumption; lower achievement
• Advertising targets fantasies and insecurities of teens and young adults.

CLASSIFYING PULMONARY DISORDERS

Infections of the Lower Airways may be ACUTE or CHRONIC; VIRAL or BACTERIAL

FLU - Responsible for 30-50% time lost from work Patient Education -- wash hands, cover mouth and nose when coughing, proper disposal of tissues, flu shots - "SHOOO the FLU" Management -- fluids, rest, ASA, pseudophendrine, nasal spray, guaifenesin

PNEUMONIA --

Acute infection of lung tissue resulting from inhalation or transport via bloodstream of infectious agents, noxious fumes, or radiation therapy. An acute inflammation of the lung parenchyma associated with the production of exudate.

Etiology

• Involves acute inflammation of the lung tissue that can reslut from inhalation of an infectious agent, transport of organisms via the bloodstreem, aspiration, or inhalation of noxious fumes or chemicals.
• Classified according to the causative organism and is further subdivided according to community versus nosocomail acquisition.
• Causative agents include:

Bacterial:

• Staphylococcus aureus, Streptococcus pneumoniae (most common community acquired), Streptococcus pyogenes, Pseudomonas aeruginosa, Hemophilus influenzae (Gram - bacillus), and Klebsiella pneumoniae.

Viral:

• Mycoplamsm pneumoniae

Fungal:

• Histoplasma capsulatum and Coccoidiodes immitus

Mycobacteria:

• Irritating chemicals such as chlorine

EPIDEMIOLOGY:

• Pneumonia is the leading cause of infectious disease deaths in the U.S.
• 3 million cases annually; now more than ever antibiotic resistant infecting microbial organisms
• 70% of cases occur in persons with chronic illnesses
• Streptococcus Pneumoniae most common microbe although many different agents may cause infection. (ie - pneumocystic carini pneumoniae - PCP -- ?fungus most frequently seen in HIV+ patients)

PREVENTION --

Same as for colds, flu. Pneumonia is often associated with URI. Pneumonia vaccine.

RISK FACTORS (for nosocomial infection)

• > 60 years old
• Prolonged hospitalization
• Serious underlying disease state or recent surgery
• Malnutrition or prolonged immobility
• Endotracheal intubation, tracheostomy, or mechanical ventilation, invasive lines or monitoring devices.

ASSESSMENT:

S&S

Subjective:

• History of recent upper respiratory tract infection
• Dyspnea
• fever and chills
• chest pain on inspiration
• presence of sputum
• cough
• weakness and fatigue

Viral and atypical pneumonia symptoms

• low grade fever
• fatigue and malaise

Objective:

• Painful, dry cough, changing to a productive coug with green, yellow, or rusty sputum depending on the organism.
• Marked elevation in temperature with shaking chills.
• Tachypnea, inspiratory rales, and dullness to percussion
• Lethargy
• Confusion
• Evidence of lung consolidation on physical examination
• Increased fremitus

LAB FINDINGS/DIAGNOSTIC TESTS:

• Obtain C&S
• Chest x-ray
• Increased WBC (15,000-25,000)
• ABG's indicative of hypoxemia

NURSING DIAGNOSES:

• Ineffective airway clearance Gas Exchange,
• Impaired Infection, Actual -- Lungs Pain Secondary to Respiratroy Infection Nutrition,
• Altered < Body Requirements R/T Increased Demands Knowledge Deficits Regarding Self-Care,
• Prevention of Spreading Infection Fluid deficit R/T Fever/Anorexia

PLANNING & MANAGEMENT:

• Can be treated outpatient if no complications Antibiotics (parenterally times 2-3 days If hospitalized,
• IV antibiotics times 5-10 days
• Diagnostic tests: chest x-ray, sputum for C&S, ABG's, CBC
• Broad Spectrum Antibiotic unless sputum C&S indicates need for a specific antimicrobial
• O2 with humidity
• TCDB, splint while coughing
• High caloric, high protein diet
• Bed rest with BRP,
• warmth
• Analgesics, Antipyretics
• HOB elevated 30 degrees

.....Carpenito, L.J. (1995). Nursing Diagnosis: Application to clinical practice (6th ed.).  Philadelphia: J.B. Lippincott Co.

.....Clark, J., Sanese, S., & McKinley, C. (1997). Senior Practicum Independent Study - Respiratory. University of North Florida.

.....Garner, C. (1997). Class Notes. University of North Florida.

.....Hudson, F., Payne-Coleman, S., & Windom Jones, S. (1998). Senior Practicum Independent Study - Respiratory. Unviersity of North Florida

.....Lewis, Collier, & Heitkemper (1996 ). Medical-Surgical Nursing

.....Lilly, L.L., Aucker, R.S., & Albanese, J.A. (1996). Pharmacology and the nursing process. New York: Mosby-Year Book, Inc.

.....Price, S.A.., & Wilson, L.M. (1997). Pathophysiology: Clinical concepts of diseae processes (5th ed.). St. Louis, MO: Mosby-Year Book, Inc.

......Potter, P.A., & Perry, A.G. (1997). Fundamentals of Nursing: Concepts, Process,

and Practice. Naples, FL: Mosby.

.....Robinson, K. (1997). Class handout - Health Problems of the Adults, Unviersity of

North Florida.

.....Watson, J., & Jaffe, M.S. (1995). Nurse's manual of laboratory and diagnostic tests (2nd ed.). Philadelphia: F.A. Davis Company

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