COPD Scenario

Jack Little is a 59-year-old panel beater with a past medical history of smoking two packs of cigarettes per day for approximately 40 years (80 pack years), chronic bronchitis, and corpulmonale. Jack was on holidays with his wife in the high, mountainous area when became extremely short of breath. His wife took him to the Emergency Department (ED). On presentation to the ED, Jack was agitated and dyspnoeic at rest and had a Glasgow Coma Scale (GCS) of 15. His physical examination revealed the presence of loud wheeze in the mid-lung fields, a temperature of 38.5 " C, SpO2 88% on room air and a respiratory rate of 28 breaths/min. Jack's lips were bluish color, and he complained of new-onset ankle swelling. During the past three days, Jack has had a productive cough and was expectorating thick, tenacious, green sputum in the morning on waking up. Dr. Santorini ordered a preliminary blood test, chest X-ray and ECG that revealed: • Blood test - moderate elevation of total white blood cell count (13.0 x 109 / L) • Chest X-ray -- hyperinflation with flattened diaphragm, increased anteroposterior diameter, no infiltrates or effusions • ECG -- normal. Based on the preliminary test results Dr. Santorini suspects an infective exacerbation of Jack's chronic bronchitis. Jack was admitted to the medical ward in the Blue Mountains Medical Centre and prescribed pharmacological therapy consisting of intravenous amoxycillin with clavulanic acid, inhaled salmeterol and inhaled ipratropium. Furthermore, Dr. Santorini orders two additional tests, arterial blood gas analyses and spirometry. Arterial blood gas analyses revealed pH of 7.32, PaCO2 of 56 and PaO2 of 62. Spirometry results showed decreased tidal volume and decreased forced expiratory volume in 1 second (FEV1).

I. COPD: Sign and Symptoms

Patients with Chronic Obstructive Pulmonary Disorder generally present with a combination of signs and symptoms of chronic bronchitis, and emphysema including the following stated signs and symptoms: (1) cough that is generally worse in the mornings and that produces colorless sputum in a small amount; (2) acute chest illness; (3) breathlessness stated to be the most significant of all symptoms but generally not occurring until the age of sixty; and (4) wheezing. (Medscape, 2013, p.1) The patient in this scenario smoked for many years and already had a history of chronic bronchitis, and corpulmonale. While in the mountains, the disease was noted to progress and specifically, the patient developed a loud wheeze in the mid-lung fields. The patient had a productive cough and noted to be expectorating thick, tenacious, green sputum in the morning after he awakened.

During the past three days, Jack has had a productive cough and was expectorating thick, tenacious, green sputum in the morning on waking up. The Arterial Blood Gases analyses show that the patient's blood gases are slightly below normal. Patients with a low pH, are said to be "acidemic." (Luks, nd, p.2) PaCO2 is high indicating respiratory acidosis in the patient. Reparatory acidosis can be caused by emphysema, drug overdose, respiratory arrest, or airway obstruction. The treatment indicated is improvement of ventilation. Co2 can be viewed as an acid and respiratory acidosis occurs due to the failure of the lungs to exhale adequate Co2. Respiratory acidosis occurs when the pH is more than 7.35 and the PCOs is less than 45.

Spirometry results showed decreased tidal volume and decreased forced expiratory volume in 1 second (FEV1). FEV1 represents "Forced expiratory volume in one second; the volume of air exhaled in the first second under force after a maximal inhalation." (Barriero and Perillo, 2004, p.1)

Severe COPD includes the symptoms of: (1) Tachypnea and respiratory distress due to simple activities; (2) the use of "accessory respiratory muscles and paradoxical indrawing of lower intercostal spaces (Hoover sign)"; (3) Cyanosis; (4) Elevated jugular venous pulse (JVP); and (5) Peripheral edema. (Medscape, 2013, p.1)

An thoracic examination of the patient will reveal: (1) hyperinflation known as 'barrel chest'; (2) wheezing; (3) breath sounds that are diffusely decreased; (4) hyperreonance on percussion and (5) prolonged expiration. (Medscape, 2013, p.1) Also included in the symptoms during thoracic examination are "Coarse crackles beginning with inspiration in some cases." (Medscape, 2013, p.1)

There are specific characteristics that enable the differentiation between chronic bronchitis and emphysema. Characteristics...

(Medscape, 2013, p.1)
COPD is formally diagnosed by use of spirometry and specifically "when the ratio of forced expiratory volume in 1 second over forced vital capacity (FEV1/FVC) is less than 70% of that predicted for a matched control, it is diagnostic for a significant obstructive defect." (Medscape, 2013, p.1)

Stated as criteria for assessment of the severity of the airflow obstruction are the following:

(1) Stage I (mild): FEV1 80% or greater of predicted

(2) Stage II (moderate): FEV1 50-79% of predicted

(3) Stage III (severe): FEV1 30-49% of predicted

(4) Stage IV (very severe): FEV1 less than 30% of predicted or FEV1 less than 50% and chronic respiratory failure. (Medscape, 2013, p.1)

The findings of Arterial blood gas (ABG) are stated as follows:

(1) ABGs provide the best clues as to acuteness and severity of disease exacerbation

(2) Patients with mild COPD have mild to moderate hypoxemia without hypercapnia

(3) As the disease progresses, hypoxemia worsens and hypercapnia may develop, with the latter commonly being observed as the FEV1 falls below 1 L/s or 30% of the predicted value

(4) pH usually is near normal; a pH below 7.3 generally indicates acute respiratory compromise

(5) Chronic respiratory acidosis leads to compensatory metabolic alkalosis (Medscape, 2013, p.1)

It is reported that in patients with emphysema, frontal and lateral chest radiographs reveal: (1) Flattening of the diaphragm; (2) Increased retrosternal air space; (3) A long, narrow heart shadow; (4) Rapidly tapering vascular shadows accompanied by hyperlucency of the lungs; (5) Radiographs in patients with chronic bronchitis show increased bronchovascular markings and cardiomegaly. (Medscape, 2013, p.1)

High resolution CT has the following advantages:

(1) Greater sensitivity than standard chest radiography

(2) High specificity for diagnosing emphysema (outlined bullae are not always visible on a radiograph)

(3) May provide an adjunctive means of diagnosing various forms of COPD (eg, lower lobe disease may suggest alpha1-antitrypsin (AAT) deficiency

(4) May help the clinician determine whether surgical intervention would benefit the patient. (Medscape, 2013, p.1)

II. Rationale for Additional Tests Ordered and Analyses and Findings of Test

Other tests reported are the following:

(1) Hematocrit -- Patients with polycythemia (hematocrit greater than 52% in men or 47% in women) should be evaluated for hypoxemia at rest, with exertion, or during sleep

(2) Serum potassium -- Diuretics, beta-adrenergic agonists, and theophylline act to lower potassium levels

(3) Measure AAT in all patients younger than 40 years or in those with a family history of emphysema at an early age

(4) Sputum evaluation will show a transformation from mucoid in stable chronic bronchitis to purulent in acute exacerbations

(4) Pulse oximetry, combined with clinical observation, provides instant feedback on a patient's status

(5) Electrocardiography can help establish that hypoxia is not resulting in cardiac ischemia and that the underlying cause of respiratory difficulty is not cardiac in nature

(6) The distance walked in 6 minutes (6MWD) is a good predictor of all-cause and respiratory mortality in patients with moderate COPD; patients with COPD who desaturate during the 6 MWD have a higher mortality rate than do those who do not desaturate

(7) Two-dimensional echocardiography can screen for pulmonary hypertension

(8) Right-sided heart catheterization can confirm pulmonary artery hypertension and gauge the response to vasodilators. (Medscape, 2013, p.1)

III. Rationale of Medications and Mechanisms of Action, Adverse Effects and Potential Drug-Drug and/or Patient-Drug Interaction

The patient was prescribed (1) amoxycillin with clavulanic acid, (2) inhaled salmeterol and (3) inhaled ipratropium. Amoxycillin with clavulanic acid was prescribed due to moderate exacerbation which includes presence of microorganisms plus inhaled salmeterol and inhaled ipratropium" (Prosser and Bollmeier, nd,…