Urinalysis: Chemical Tests and Microscopic Examination

Urine Analysis

• Chemical Tests: Include heat & acetic acid test for proteins, Benedict's test for sugars, and Fouchet's test for bilirubin.
• Microscopic Examination: Analyze sediment under a microscope to examine cells, bacteria, crystals, and casts.
• Normal Findings: Few epithelial cells, occasional RBCs, few crystals.
• Abnormal Findings: Various cells (RBCs, WBCs), bacteria, crystals, and casts.

Types of Casts

• Acellular Casts: Hyaline, granular, waxy, fatty, pigment, and crystal casts.
• Cellular Casts: Red cell casts, white cell casts, epithelial cell casts.

Miscellaneous Structures in Urine

• Bacteria: Presence can indicate infection.
• Microfilaria: Parasitic infections.
• Trichomonas vaginalis: Protozoal infections.
• Schistosoma haematobium: Parasitic infections.
• Spermatozoa: Normally present in males.
• Oval Fat Bodies: Associated with nephrotic syndrome.
• Yeast: Can indicate fungal infections.

Urine Dipsticks

• Usage: Rapid screening tool with results in 2 minutes.
• Each square on the strip: Tests for different components in the urine.

Macroscopic Examination

• Volume: Normal: 600-2000 ml/day, Oliguria: < 400 ml/day, Polyuria: > 2500 ml/day.
• Color: Normal: Pale yellow due to urochrome, Abnormal colors can indicate various conditions.
• Odor: Normal: Slight aromatic odor, Strong or unusual odors can suggest infection or metabolic disorders.
• Reaction (pH): Normal: 4.6-8, Affected by diet, medication, and pathological conditions.
• Specific Gravity: Normal: 1.003-1.035, High specific gravity indicates concentrated urine, Low specific gravity indicates diluted urine.
• Osmolality: Measures the urine's ability to concentrate solutes.

Chemical Examination

• Proteins: Normal: Trace to none, Elevated levels can indicate kidney disease.
• Sugars: Normal: Absent, Presence can indicate diabetes mellitus.
• Ketone Bodies: Normal: Absent, Presence can indicate uncontrolled diabetes, starvation, or a high-fat diet.
• Bilirubin: Normal: Absent, Presence can indicate liver disease or bile duct obstruction.
• Bile Salts: Normal: Absent, Presence can indicate liver or bile duct disease.
• Urobilinogen: Normal: Small amounts, Increased levels can indicate liver disease or hemolysis.
• Blood: Normal: Absent, Presence can indicate urinary tract infection, trauma, or stones.

Phlebotomy

• Definition: Phlebotomy: The practice of cutting or puncturing a vein, primarily to obtain blood specimens for testing.
• Phlebotomist: A medical professional who performs phlebotomy, collects, processes, and transports blood specimens.
• Responsibilities: Include collecting, processing, and transporting blood specimens.
• Vein Selection: Preferred veins: basilic, cephalic, and median cubital veins in the antecubital fossa.
• Approach and Communication: Introduce yourself, check patient ID, explain the procedure, gain consent, and review the patient's history.
• Patient Identification: A three-step process: ask for name and DOB, compare with the test requisition form, and validate using a medical record number or ID.
• Hand Hygiene: Crucial for reducing disease spread, gloves should be worn when handling blood and body fluids.
• Locating the Vein: Stages: visual inspection and palpation, avoid veins near infections, bruises, phlebitis, and edematous limbs.
• Improving Venous Access: Methods include tourniquet application, fist clenching, light tapping, using heat, and lowering the arm.
• Tourniquet Application: Should be tight enough to impede venous return but not arterial flow, placed 7-8 cm above the site, and left on for less than a minute.
• Skin Preparation: Asepsis is vital for venipuncture, the skin should be cleaned, especially for blood cultures or if the patient is at higher infection risk.
• Equipment and Positioning: Preparation: necessary items include skin cleansing wipes, tourniquet, gloves, gauze swabs, adhesive dressing, needles, blood collection tubes, and sharps container.
• Procedure of Venipuncture: Steps: greet and identify the patient, position and prepare them, perform hand hygiene, apply tourniquet, select and palpate the vein, assemble equipment, clean the site, perform the puncture, fill the tube, remove tourniquet, withdraw needle, label tubes, and ensure the patient's well-being.
• Types of Blood Samples: Whole Blood, Serum, and Plasma.
• Complications and Prevention: Complications: hematoma, syncope, and hemolysis, with preventive measures provided.
• Capillary Puncture: Used as an alternative when venipuncture is not advisable, especially for newborns, infants, and certain patient groups.