Pulmonary Function Tests Overview

Study Notes

Assess respiratory function, determine extent of dysfunction, response to therapy, and screen for potential hazards in industries.
Administered using a spirometer.
Indications:
- Chronic respiratory disorders
- Patients undergoing thoracic and upper abdominal surgery
- Obese individuals
- Symptomatic patients with a history suggesting high risk.
Percentage Predicted Value reflects the patient's performance compared to an average based on age, gender, race, and height.
Patient preparation:
- Avoid smoking for 24 hours.
- Avoid alcohol for at least 4 hours.
- Avoid vigorous exercise for at least 30 minutes.
- Avoid wearing tight clothing.
- Avoid large meals 2 hours before the test.
- Avoid short-acting bronchodilators for 4 hours.
- Avoid long-acting beta-2-agonist inhalers for 12 hours.
- Avoid slow-release respiratory function affecting medicines, and theophylline-based drugs for 24 hours.

Continuously monitors oxygen saturation of hemoglobin in a non-invasive manner.
Probe or sensor is attached to the fingertip, forehead, earlobe, or bridge of the nose.
Monitors light signals generated by the oximeter and reflected by blood pulsing through the tissue at the probe.
Results:
- SpO2 greater than 95%: normal.
- SpO2 less than 95%: indicates hypoxia (tissues are not receiving enough oxygen).
Factors affecting pulse oximetry readings:
- Anemia
- Abnormal Hemoglobin
- Carbon Monoxide Poisoning
- Patient movement (shivering)

Culture identifies the pathogen present.
Sensitivity tests determine the effectiveness of different drugs against the identified pathogen.
Sensitivity results:
- Sensitive: Drug is effective.
- Intermediate: Drug may be effective, but higher doses may be required.
- Resistant: Drug is not effective.
Cultures should be obtained before initiating antibiotic therapy.
Preliminary results are typically available within 24 hours.
Final results are available after 48 to 72 hours.
Specimen types:
- Throat swab: Detects streptococcal infections.
- Nasal/nasopharyngeal swab: Detects Staphylococcus aureus and influenza.
- Sputum: Detects various pathogens.

Sputum is thick mucus produced in the lungs.
Studies:
- Gram staining: Rapid method to detect bacterial infection. Differentiates between gram-positive and gram-negative bacteria.
- Culture and sensitivity: Identifies the specific pathogen and determines the effectiveness of drugs.
- Acid-fast bacilli: Test for tuberculosis.

Best time for collection is early in the morning before food or fluid intake.
Patient should rinse their mouth with water before collection.
Patient should take a few deep breaths and cough deeply into a sterile container.
Oral care should be offered after sputum collection.

Detects fluid densities, tumors, foreign bodies, and other pathological conditions in the lungs.
Contraindicated in pregnancy.
Nursing interventions: Ensure patient is aware that x-rays do not necessitate fasting and are not painful.

Provides cross-sectional images of the chest using narrow-beam x-rays.
Nursing interventions:
- Inform the patient of staying in the supine position for 30 minutes.
- Assess for iodine allergies if a contrast medium will be used.
- Monitor kidney function if a contrast medium is used.
- Maintain NPO for 4 hours before the procedure or as ordered.

Uses magnetic fields and radiofrequency instead of radiation for imaging.
Provides more detailed diagnostic images than x-rays and CT scans.
Contraindications:
- Metallic implants (absolute contraindication).
- Pacemakers (absolute contraindication).
- Morbid obesity.
- Confused or agitated patients.
- Claustrophobia.
Nursing interventions: Address patient concerns regarding contraindications and claustrophobia.