3011686 Common Laboratory Procedures

Common Laboratory procedures: Nursing Responsibilities and Implications

3 Phases of Diagnostic testing Pretest specimen collection and VS monitoring nursing care

Client preparation Intra-test Post-test Monitoring and follow-up

Related Nursing Diagnoses Anxiety Fear Impaired physical mobility

Deficient knowledge

BLOOD TESTS CBC Hemoglobin, Hematocrit, WBC, RBC and platelet Serum Electrolytes Arterial blood gases Blood Chemistry Drug and Hormone Assay

Complete Blood Count

Specimen: Venous blood Pretest: obtain syringe, tourniquet, vial with appropriate anticoagulant Intratest: Cubital vein commonly used for venipuncture Post-test: direct pressure and observe for bleeding, label vial

Normal values for CBC

RBC (M) 4.7-6.1/ (F) 4.2-5.4 Hgb (M) 14-18/ (F) 12-16 mg/dL Hct (M) 42-52/ (F) 3347 % WBC 5-10,000 cells/cubic cm Differential count Neutrophils- 55- 70% Lymphocytes- 20-40% Monocytes- 2-5% Eosinophils- 1-4% Platelets 150,000400,000

Table. 11.2

CBC Normal WBC count Increased WBC (Leukocytosis) Increased Neutrophils Increased Lymphocytes Increased Eosinophils 5-10,000 cell/cm3 More than 10, 000 ACUTE bacterial infection CHRONIC bacterial infection VIRAL infection PARASITIC infection

Serum Electrolytes Specimen: venous blood Pretest/Intratest/Post-test- same Commonly ordered: Sodium- 135-145 mEq/L Potassium- 3.5-5.0 mEq/L Chloride- 95-105 mEq/L Magnesium- 1.3 to 2.1 mEq/L Calcium- 8 to 10 mg/dL

Serum Electrolytes Problems can be

Hyper

if increased

Hypo

if decreased

Blood Chemistry

Specimen: Venous blood, serum Pretest/Intratrest/Post-test-same Examined are enzymes, hormones, lipid profile BUN , Creatinine, etc… Place patient on NPO for 8 h *Creatinine is produced relatively constant by muscles, excreted by the kidneys and is the RELIABLE Reflection of Renal Status

Blood Chemistry Normal values for : Creatinine: 0.7 to 1.4 mg/dL BUN: 10-20 mg/dL Creatinine clearance: 1.67 to 2.5 mL/s Serum uric acid: 2.5 to 8 mg/dL Blood osmolality= 250 to 290 mOsm/L

Blood Chemistry Enzymes/acids Uric acid SGOT/SGPT Purpose Gout detection Liver function test Rheumatoid factor For Rheumatoid arthritis Anti-DNA antibody SLE diagnosis CK-MB, LDH and Troponin Identifies Cardiac damage or muscle damage

Blood Chemistry Coagulation studies PT 12-16 seconds Purpose Measures the effectiveness of Warfarin single The BEST screening test for coagulation disorders Same as PTT, PTT 60-70 seconds aPTT 30-40 seconds Bleeding time 1-9 minutes measures effectiveness of HEPARIN Platelet Measures (more specific than function PTT)

Others Blood Chemistry Purpose Measures the rate at which the RBCs settle out of the anticoagulated blood Elevates in inflammation auto To detect immune diseases ESR (erythrocyte sedimentation rate) 10-20 mm/hour Blood lipids Cholesterol= 150-200 hyperlipidemia mg/dL Triglycerides= 140-200 mg/dL

Diabetes Mellitus DIAGNOSTIC CRITERIA FBS equal to or greater than 126 mg/dL (7.0mmol/L) hour FBS80-109 mg/dL)

(Normal 8

Diabetes Mellitus DIAGNOSTIC CRITERIA OGTT value 1 and 2 hours post-prandial equal to or greater than 200 mg/dL Normal OGTT 1 and 2 hours post-prandial- is

Diabetes Mellitus DIAGNOSTIC CRITERIA RBS of equal to or greater than 200 mg/dL PLUS the 3 P’s

Diabetes Mellitus DIAGNOSTIC CRITERIA Glycosylated hemoglobin (HbA1c) is a monitoring test to assess the adherence to diabetic

Arterial Blood Gases

Specimen: arterial blood Pretest: obtain syringe with heparin, rubber stopper, container with ice Intratest: usual site-radial artery, perform Allen’s test Posttest: Apply direct pressure on site for 5-10 minutes, send specimen with occluded needle on ice

Normal ABG values pH 7.35-7.45 26 mEq/L Base excess -2 to +2

pCO2 35-45 mmHg O2 sat 95-98%

paO2 80-100 mmHg

HCO3 22-

ABG interpretation Value pH paO2 SaO2 paCO2 HCO3 Normal 7.35-7.45 95-100 mmHg 95-98% 35-45 mmHg Acidosi s Below 7.35 Alkalosi s Above 7.45 Respirat ory >45 22-26 mEq/L Metaboli c <22 Respirat ory <35 Metaboli c >26

Urine Analysis Specimens Clean-voided urine for routine urinalysis Cleancatch or midstream urine for urine culture Suprapubic and catheterized urine for urine culture

Routine Urinalysis

Specimen: Clean voided Pretest: give clean vial and instruct to void directly into the specimen bottle Intratest: Allow a 10 ml collection Post-test: prompt delivery to laboratory *First voided urine in a.m. is highly concentrated, more uniform concentration and with more acidic pH

Urine Culture: Normal is <100,000

Specimen: clean catch, midstream or catheterized urine Pretest: Instruct to wash and dry genitalia/perineum with soap and water. (M)- circular motion, (F)front to back direction Intratest: Midstream urine, 30-60 ml Post-test: Cap and label, prompt delivery and documentation

Special Urine Collection

Infants Special urine bag Or cut a hole of the diaper (front for the boy, middle for the girl) pulling out through the hole the special bag Children May use potty chair or bedpan Give another vial to play with, allow parent to assist Elderly Assistance may be required

Timed-urine collection

Collection of ALL urine voided over a specified time Refrigerated or with preservative Pretest: Specimen container with preservative, receptacle for collection, a post sign Intratest: At the start of collection, have patient void and discard the urine At the end of collection period, instruct to completely void and save the urine Post test: Documentation

Catheter specimen Sterile urine Insert needle of the syringe through a drainage port Only done with the rubber catheter not the plastic, silastic or silicone catheter. Intratest: Clamp catheter x 30 mins if no urine Wipe area where needle will be inserted 30-45° angle, 3 ml for culture Post-test : Unclamp catheter after collection

Stool Analysis Occult Blood Bacteria Viruses

GUAIAC test

Steatorrhea

Ova/Parasites

General Nursing consideration for stool collection

Pretest: Determine purpose/s, obtain gloves, container and tongue blade Intratest: Instruct to defecate in clean bed pan Void before collection Do not discard tissue in bedpan Obtain 2.5 (1 inch) formed stool 15-30 ml of liquid stool Post-test: prompt delivery

Occult Blood: Guaiac Test Detect the presence of enzyme: Peroxidase (+) blue color positive guaiac Restrict intake of red meats, some medications and Vitamin C for 3-7 days

FALSE (+): red meat, raw fruits and vegetables especially radish, turnip, melon and horseradish; meds like aspirin, NSAIDS, iron and anticoagulants FALSE (-): Vitamin C, ingested 250 mg per day from any source

Sputum Analysis For Culture and sensitivity For sputum cytology For sputum AFB For monitoring of the effectiveness of therapy

Sputum examination

Pretest: Morning specimen is collected Intratest: Mouthwash with plain water Deeply inhale x 2 then cough Wear gloves in collecting specimen Expectorate needed- 1-2 Tbsp or 15-30 ml Post-test: oral care and prompt delivery to lab

VISUALIZATION PROCEDURES Invasive procedures are direct methods and need CONSENT Non-invasive procedures are indirect methods and may need written consent in some instances

Visualization procedures They can be: Radiographic procedures “Scopic” procedures

GIT Visualization Barium Swallow- UGIS Pretest: written consent, NPO the night Intratest: administer barium orally, then followed by X-ray Post-test: Laxative for constipation, increased fluids, assess for intestinal obstruction , warn that stool is light colored!

GIT Visualization Barium Enema- LGIS Pretest: Informed consent, NPO the night, Enema the morning Intratest: Position on LEFT side, administer enema, then Xray follow Posttest: Cleansing enema , Laxative for constipation, assess for intestinal obstruction

GIT Visualization Esophagogastroscopy Pretest: Informed consent, NPO for 8 hours, warn that gag reflex is abolished Intratest: Position on LEFT side during scope insertion Post-test: NPO until gag returns. Monitor for complications

GIT Visualization

Anoscopy, proctoscopy, proctosigmoidoscopy, colonoscopy Pretest: Consent, NPO, and enema administration the morning Intratest: Position on the LEFT side during scope insertion Post-test: Monitor for complications

Gallbladder Oral cholescystogram PTC ERCP Ultrasound

IV Cholecystogram

X-ray visualization of the gallbladder after administration of contrast media intravenously Pre-test: Allergy to iodine and seafoods Intra-test: ensure patent IV line Post-test: increase fluid intake to flush out the dye, Assess for delayed hypersensitivity reaction to the dye like chills and N/V

Oral Cholecystogram

X-ray visualization of the gallbladder after administration of contrast media Done 10 hours after ingestion of contrast tablets Done to determine the patency of biliary duct

Endoscopic retrograde cholangiopancreatography

Examination where a flexible endoscope is inserted into the mouth and via the common bile duct and pancreatic duct to visualize the structures Iodinated dye can also be injected after for the x-ray procedure

Endoscopic retrograde cholangiopancreatography

Pre-test: consent, NPO for 12 hours, Allergy to sea-foods, Atropine sulfate Intratest: Gag reflex is abolished, Position on LEFT side Post-test: NPO until gag reflex returns, Position side lying and monitor for perforation and hemorrhage

Percutaneous Transhepatic Cholangiogram Under fluoroscopy, the bile duct is entered percutaneously and injected with a dye to observe filling of hepatic and biliary ducts

Ultrasound of the liver, gallbladder and pancreas Consent MAY be needed Place patient on NPO!!! Laxative may be given to decrease the bowel gas

Urinary Visualization Non-invasive: KUB, IVP, Ultrasound Pretest: Elicit allergy to iodine and seafood, NPO after midnight Intra-test: IV iodinated Dye is administered then X-ray is taken Post-test: Increase fluids to flush the dye. Documentation, VS monitoring

Urinary Visualization

Invasive: retrograde cystourethrogram Pretest: Elicit allergy to iodine and seafood Intra-test: catheter is inserted with dye is administered then X-ray is taken as patient voids Post-test: Increase fluids to flush the dye. Documentation, VS monitoring

Pulmonary visualization

Invasive: Bronchoscopy, laryngoscopy Non-invasive: CXR and Scan

Bronchoscopy

Purpose: Diagnostic and therapeutic Pretest: Consent, NPO, client teaching, antianxiety drugs Intratest: gag reflex is abolished, instruct to remain still during procedure, FOWLER or SUPINE Post-test: NPO until gag reflex returns, monitor patient for complication like perforation/bleed

Pulmonary function test Test to determine lung volumes and capacities

LUNG VOLUMES

1. Tidal volume – TV 2. Inspiratory Reserve VolumeIRV 3. Expiratory Reserve VolumeERV 4. Residual volume- RV

LUNG CAPACITIES Lung volume + another lung volume 1. Inspiratory Capacity- IC 2. Functional Residual CapacityFRC 3. Vital capacity- VC 4. Total Lung capacity- TLC

Pulmonary "Volumes” 1. Tidal Volume: -volume of air inspired or expired with each normal breath, about 500ml 2. Inspiratory Reserve Volume -extra volume of air than can be inspired over & beyond the normal tidal volume, about 3000ml

Pulmonary "Volumes” 3. Expiratory Reserve Volume -amount of air that can still be expired by forceful expiration after the end of a normal tidal expiration -about 1100ml 4. Residual Volume -volume of air still remaining in the lungs after the most forceful expiration, averages about 1200ml

Pulmonary "Capacities:" 1. Inspiratory Capacity -equals TV + IRV, about 3500ml -amount of air that a person can breathe beginning at the normal expiratory level & distending his lungs to maximum amount 2. Functional Residual Capacity -equals ERV + RV -about amount of air remaining in the lungs at the end of normal expiration, about 2300ml

Pulmonary "Capacities:" 3. Vital Capacity -equals IRV + TV + ERV or 1C + ERV, about 4600ml -maximum amount of air that a person can expel from the lungs after filling the lungs to their maximum extent & expiring to the maximum extent 4. Total Lung Capacity -maximum volume to which the lungs can be expanded with the greatest possible effort -volume of air in the lungs at this level is equal to FRC (2300ml) in young adult

Cardiac Visualization Invasive: angiography. Cardiac catheterization Stress ECG

Non-invasive: ECG, Echocardiography,

The Cardiovascular System LABORATORY PROCEDURES ECHOCARDIOGRAM Non-invasive test that studies the structural and functional changes of the heart with the use of ultrasound No special preparation is needed

2 D-echocardiogram

Angiography

Pretest: informed consent, allergy to dyes, seafood and iodine Intratest: Monitor VS Post-test: maintain pressure dressing over puncture site Immobilize for 6 hours

Cardiac Catheterization

Introduction of catheter into heart chambers Pretest: informed consent, allergy to dyes, seafood and iodine, NPO 8-12 hours Intra-test: Empty bladder, Monitor VS, explain palpitations Post-test: maintain pressure dressing over puncture site Immobilize for 6-8 hours with extremity straight

Myelography

Radiographic examination of the spinal column and subarachnoid space to help diagnose back pain causes Pre-test: Consent, NPO, allergy to seafoods Intra-test: like LT Post-test: supine for 12 hours

Arthroscopy

Insertion of fiber optic scope into the joint to visualize it, perform biopsy Performed under OR condition After care: Dressing over the puncture site for 24 hours to prevent bleeding Limit activity for several days (7 usually)

Arthrogram

X-ray visualization of the joint after introduction of contrast medium Pre-test: consent, allergy to seafoods Post-test: Dressing over puncture site and limit joint activity

Electromyelography

Records the electrical activity in muscles at rest and during involuntary and electrical stimulation Detects disorders such as MG, MS and Parkinson’s Explain the use of electrode inserted into the muscles Mild discomfort may be experienced About 45 minutes for one muscle

CT scan Painless, non-invasive, xray procedure

Mechanism: distinguish density of tissues

MRI

Painless, non-invasive, no radiation Creates a magnetic field Contraindications: (+) pacemaker (+) metal prosthesis Client teaching: Lie still during the procedure for 60-90 minutes Earplugs to reduce noise discomfort Claustrophobia No radiation

ASPIRATION AND BIOSPY Aspiration: withdrawal of fluid of tissue Invasive procedure needs INFORMED CONSENT

Biopsy: removal and exam

Lumbar Puncture

Withdrawal of CSF from the arachnoid space Purpose: diagnostic and therapeutic To obtain specimen, relieve pressure and inject medication Pretest: consent, empty bladder

Lumbar Puncture

Intra-test: Site used-between L4/L5 Position- flexion of the trunk Post-test: Flat on bed (8-12 hours) Offer fluids to 3 Liters Oral analgesic for headache Monitor bleeding, swelling and changes in neurologic status

Abdominal Paracentesis Withdrawal of fluid from the peritoneal space Purpose: diagnostic and therapeutic Pretest: consent, empty bladder Position: sitting

Site: midway between the umbilicus and symphysis

Abdominal Paracentesis

Intratest: 1,500 ml maximum amount collected at one time, Monitor VS Post-test: monitor VS, bleeding complication Measure abdominal girth and weight

Thoracentesis Removal of fluid from the pleural space Purpose: Diagnostic and therapeutic Pretest: Consent, teach to avoid coughing Position: sitting with arms above head

Thoracentesis

Intra-test: Support and observation Post-test: Assess VS Position Postprocedure: lie on the UNAFFECTED SIDE with head elevated 30° x 30 minutes to facilitate expansion of the affected lungs

Bone marrow Biopsy Removal of specimen of bone marrow Purpose: diagnostic Pretest: consent, teach that procedure is painful Site: POSTERIOR SUPERIOR ILIAC CREST (adult); PROXIMAL TIBIA (pedia) or lateral

Position: prone

Bone marrow Biopsy

Intratest: Monitor, maintain pressure dressing over punctured site X 10 mins Posttest: Asses for discomfort, administer prescribed pain meds

Liver Biopsy Liver tissue obtained for diagnostic purpose Pretest: consent, administer Vitamin K, monitor bleeding parameters, NPO 2 hours before procedure Position: Supine or semi-fowlers with upper right quadrant of abdomen exposed

Liver Biopsy

Intra-test: Monitor VS Take few deep inhalation and exhalation and hold final breath in exhalation x 10 seconds as needle is injected Post-test: monitor VS, bleeding Position post-procedure: RIGHT side-lying with folded towel/pillow under biopsy site for 4-6 hours

Papanicolau Smear

Done as screening test for cervical cancer, for culture Pre-test: no coitus for 23 days, no menstrual bleeding Intra-test: Lithotomy, speculum with water for lubrication, specimen obtained for cervix and vagina Post-test: monitor for bleeding

The Cardiovascular System LABORATORY PROCEDURES ELECTROCARDIOGRAM (ECG) A non-invasive procedure that evaluates the electrical activity of the heart Electrodes and wires are attached to the patient

What the waves represent? P wave= Atrial Depolarization QRS= Ventricular Depolarization T wave= Ventricular REPOLARIZATION

LABORATORY PROCEDURES CVP The CVP is the pressure within the SVC blood is returned to the SVC and right atrium

Reflects the pressure under which

LABORATORY PROCEDURES CVP

Normal CVP is 0 to 8 mmHg/ 4-10 cm H2O

LABORATORY PROCEDURES Measuring CVP 1. Position the client supine with bed elevated at 45 degrees (CBQ) 2. Position the zero point of the CVP line at the level of the right atrium. Usually this is at the MAL, 4th ICS 3. Instruct the client to be relaxed and avoid coughing and straining.

Tubes Levine Salem Sump tube Gastrostomy tube Jejunostomy tube

Drainage Penrose Drain Hemovac Pleuravac Jackson-Pratt

Asked in the local boards DRE Snellen’s chart

Weber’s test

Rinnes’ test

DRE

Position: Left Lateral or Sim’s position with upper leg acutely flexed. Females can also be examined in lithotomy Ask client to BEAR DOWN To accentuate rectal fissure, prolapse ,polyps To relax the anal sphincter

Snellen’s Chart: test for visual acuity 20 ft or 6 m distance 3 readings: L, R and Both eyes Report: 20/ xxx Numerator: denotes the distance from the chart

Snellen’s Chart: test for visual acuity Denominator denotes the distance from which the normal eye can read the chart 20/60: the person can see at 20 feet, what a normal person can see at 60 feet.

Weber’s test

Test for lateralization and bone conduction Tuning fork is placed on top of head NORMAL: sound is heard in BOTH ears, localized at the center of the head: WEBER NEGATIVE

Weber’s test

Sound is heard BETTER in the affected ear: Bone conductive hearing loss Sound is heard only or better on the NORMAL ear: Sensorineural heating loss ABNORMAL: WEBER POSITIVE

Rinne’s Test

Test for AIR and BONE conduction Tuning fork is initially placed on the mastoid process until no vibration is heard Tuning fork is now placed in front of the ear until sound disappears

Rinne’s Test Air conduction is LONGER than bone conduction is POSITIVE Normal Rinne’s

Rinne’s Test CONDUCTIVE HEARING LOSS: Bone conduction is GREATER than or equal to the AIR conduction Abnormal is NEGATIVE RINNEs

Rinne’s Test SENSORINEURAL HEARING LOSS: No bone conduction and air conduction vibration can be assessed NEGATIVE RINNEs

Weber

Rinne’s

Rinne’s

FAILING TO PREPARE IS PREPARING TO FAIL…