Lab 1: Specimen Collection and Transportation

Specimen Collection and Transportation

• Proper specimen collection and transportation are crucial because the quality of the specimen directly affects the laboratory results.
• Specimens should be obtained properly to minimize the possibility of contaminating microorganisms that are not involved in the infectious process.

Containers for Specimen Collection

• Feces: Universal container with a spoon attached to the inside of the screw cap.
• Urine: Universal container for small quantities, and 250ml wide-mouthed screw-capped bottles for larger quantities.
• Sputum: Wide-mouthed disposable containers (not universal containers).
• Blood: Without anticoagulant for serological examination, and with EDTA for parasitological examination.
• Blood culture bottle: Must be at least large enough to hold 50ml of liquid medium and 5-10ml of patient's blood.

Syringe and Needle for Aspiration

• Used for collecting specimens from: • Wound pus • CSF • Pleural effusion • Amniotic fluid • Synovial fluid

Swabs for Specimen Collection

• Suitable for collecting exudates from: • Throat • Nose • Ear • Skin • Wounds • Accessible lesions
• Consist of sterile pledge of absorbent material (usually cotton-wool or synthetic fiber) mounted on a thin wire stick.

Special Purpose Swabs

• Baby swabs
• Pre-nasal swabs
• Post-nasal swabs
• Laryngeal swabs
• High vaginal and cervical swabs

Specimen Collection Guidelines

• Time of collection: • During the acute phase • Before antimicrobial therapy

What is Electrocardiograph?

• An Electrocardiogram (ECG) records the electrical signals in the heart.
• It's a common and painless test used to quickly detect heart problems and monitor the heart's health.

Why is ECG done?

• To diagnose many common heart problems, including irregular heart rhythms (arrhythmias), blocked or narrowed arteries in the heart, and previous heart attacks.
• To monitor heart disease treatments, such as pacemakers.

Indications for ECG

• Chest pain
• Dizziness, lightheadedness or confusion
• Heart palpitations
• Rapid pulse
• Shortness of breath
• Weakness, fatigue or a decline in ability to exercise

Heart's Electrical Activity

• The sinoatrial node, located in the right atrium, is the origin of electricity of the heart.
• The electrical activity is sent to the atrioventricular node and then to the purkinjee fibers of the heart.
• Electrically, the most important chamber of the heart is the right atrium.
• Mechanically, the most important chamber of the heart is the left ventricle.

ECG Leads

• Einthoven's triangle has three leads:
  • Lead I: direction of electricity from the right arm to the left arm.
  • Lead II: direction of electricity from the right arm to the left leg.
  • Lead III: direction of electricity from the left arm to the left leg.
• Lead II is important because it directs the electrical pulse from the right atrium to the left ventricle.

Measuring ECG

• Hospitals use 12 electrodes to measure ECG:
  • Right arm, left arm, right leg, left leg, and 8 electrodes between the 4th and 5th ribs on the left and right side of the sternum.
• A single electrode is positioned between the 4th intercostal space.

ECG Waves

• P wave: indicates depolarization of the atrium.
• QRS complex: series of waves that indicate depolarization of the ventricle.
• T wave: represents repolarization of the ventricle.

Important to Know

• The repolarization of the atrium is small and will disappear in QRS complex.
• Gel containing ions can be used to increase conductivity during ECG.
• Sodium is an important electrolyte for the heart movement, and checking the patient's electrolyte levels is important.

What do the Results Tell Us?

• Heart rate: ECG can help identify an unusually fast heart rate (tachycardia) or an unusually slow heart rate (bradycardia).
• Heart rhythm: ECG can detect irregular heartbeats (arrhythmias).
• Heart attack: ECG can show evidence of a previous heart attack or one that's currently happening.
• Blood and oxygen supply to the heart: ECG can provide information about this.
• Heart structure changes: ECG can provide clues about an enlarged heart, heart defects, and other heart problems.