Chapter 16-19 Monitoring Patients

It is important to correlate monitor values (like SpO2) with your direct clinical observation of the patient because:

• monitors can sometimes give inaccurate readings that need to be verified by clinical signs.

• monitor values are always more reliable than clinical observation.

• clinical observation is unnecessary if monitor values are normal.

• monitors can replace the need for any clinical assessment.

List two limitations of pulse oximetry:

• a. Poor perfusion can affect accuracy b. Cannot detect carbon monoxide poisoning

• c. It can measure blood pressure accurately b. It can detect all types of arrhythmias

• d. It is unaffected by nail polish or artificial nails b. It can replace arterial blood gas analysis

• e. It can diagnose anemia precisely b. It can measure respiratory rate directly

A patient is being monitored with capnography. The waveform shows a flat line despite the patient breathing. What could be happening?

• The capnography sensor is disconnected or malfunctioning.

• The patient is hyperventilating.

• The patient has a high fever.

• The patient is experiencing bradycardia.

Interpret the following ABG values:

pH: 7.32

PaCO2: 55 mmHg

HCO3-: 26 mEq/L

PaO2: 62 mmHg)

• Respiratory acidosis with hypoxemia.
• Metabolic alkalosis with hypoxemia.
• Respiratory alkalosis with normal oxygen levels.
• Metabolic acidosis with hypercapnia.

Interpret the following ABG values:

pH: 7.49

PaCO2: 30 mmHg

HCO3-: 23 mEq/L

PaO2: 92 mmHg

• Metabolic acidosis
• Respiratory acidosis
• Normal acid-base balance
• Respiratory alkalosis

Interpret the following ABG values:

pH: 7.29

PaCO2: 40 mmHg

HCO3-: 18 mEq/L

PaO2: 70 mmHg

• Metabolic acidosis with no respiratory compensation and hypoxemia.
• Respiratory acidosis with metabolic compensation and normal oxygen levels.
• Metabolic alkalosis with respiratory compensation and hypercapnia.
• Normal ABG values with mild hypoxemia.

Scenario: A 65 year old man with a history of COPD is admitted with shortness of breath.

Vitals: HR 112, RR 28, BP 148/92, Temperature 37.2 degrees Celsius, SpO2 85%

ABG: pH 7.30, PaCO2 60 mmHg, HCO3 30 mEq/L, PaO2 55 mmHg

What type of acid-base disorder is present?

• Metabolic acidosis
• Respiratory alkalosis
• Respiratory acidosis
• Metabolic alkalosis

Scenario: A 65 year old man with a history of COPD is admitted with shortness of breath.

Vitals: HR 112, RR 28, BP 148/92, Temperature 37.2 degrees Celsius, SpO2 85%

ABG: pH 7.30, PaCO2 60 mmHg, HCO3 30 mEq/L, PaO2 55 mmHg

The patient is compensating by:

• The patient is compensating by increasing respiratory rate (hyperventilation).
• Retaining carbon dioxide (hypercapnia)
• Increasing heart rate (tachycardia)
• Decreasing respiratory rate (hypoventilation)

Scenario: A 65 year old man with a history of COPD is admitted with shortness of breath.

Vitals: HR 112, RR 28, BP 148/92, Temperature 37.2 degrees Celsius, SpO2 85%

ABG: pH 7.30, PaCO2 60 mmHg, HCO3 30 mEq/L, PaO2 55 mmHg

Based on SpO2 and PaO2, the likely appropriate intervention would be:

• Perform a chest X-ray immediately.
• Increase the patient's fluid intake.
• Administer supplemental oxygen.
• Administer a bronchodilator only.

You should be cautious with oxygen therapy in COPD patients because:

• it can suppress their respiratory drive

• it always improves their lung function

• it prevents all complications

• it increases their exercise tolerance