Complete Blood Count Service

05/05/2014'

Complete Blood Count service:

a clinician’sWasithep Limvorapitak, perspective MD. Division of Hematology, Department of Internal Medicine, Faculty of Medicine, Thammasat University

Outline

! Clinical uses of CBC results ! Importance of blood smear examination

! Clinician’s response when critical result notified

! Clinician’s expectation of the service

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Introduction

! Hematology: a broad based science ! Objective: to study normal and pathologic condition of hematopoietic system

! Uses diverse scientific disciplines: biochemistry, cell biology, immunology, etc.

Wintrobe’s Clinical Hematology. 12th edition.

Introduction

! Hematologic disorders:

! Primary disease of blood or blood forming organ ! More often- secondary change from other diseases ! Symptoms and signs: maybe non-specific

! Complete Blood Count: basic test that gives considerable information

Wintrobe’s Clinical Hematology. 12th edition.

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Complete Blood Count: CBC

! Key questions:

! Is the marrow producing appropriate numbers of mature cells in the major hematopoietic lineages? ! Is the development of each hematopoietic lineage qualitatively normal?

Williams Hematology. 8th edition.

Complete Blood Count: CBC

! Automated CBC analysis:

! Rapid ! Cost-effective ! Accurate ! Quantitative screening of hematopoietic function

Williams Hematology. 8th edition.

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Complete Blood Count: CBC Parameters Unit Calculation Hb g/dL 0.8 Hct % RBC x MCV/10 RBC Cells/uL 0.6 MCV fL 0.4 MCH pg Hb x 10/RBC OD MCHC g/dL Hb x 100/Hct 0.2 RDW % WBC Cells/uL 0 WBC diff % 0 3 6 9 12 15 Platelet /uL Hb (g/dL) MPV fL

Complete Blood Count: CBC Parameters Unit Calculation Hb g/dL Hct % RBC x MCV/10 RBC Cells/uL MCV fL MCH pg Hb x 10/RBC MCHC g/dL Hb x 100/Hct RDW % WBC Cells/uL WBC diff % Platelet /uL MPV fL

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Complete Blood Count: CBC Parameters Unit Calculation Hb g/dL Hct % RBC x MCV/10 RBC Cells/uL MCV fL MCH pg Hb x 10/RBC MCHC g/dL Hb x 100/Hct RDW % WBC Cells/uL WBC diff % Platelet /uL MPV fL

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Clinical uses of CBC

! Check-up: screening for hematologic abnormalities

! Diagnosis: confirmatory for patients’ manifestations

! Pre-operative: to prevent possible complications

! Monitoring: for response or complication

Clinical uses of CBC

! MOST IMPORTANT: To use laboratory result in the context of clinical medicine, not only as lab result

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Blood smear examination

! Also a crucial examination in hematologic disorder

! Not only to differential the white cell, but to look for other abnormalities, mostly that cannot be reported from automated CBC

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Blood smear examination

! CBC plus blood smear: help in reaching provisional diagnosis

! Next step investigation then can be done properly and effectively

Blood smear examination

! Unselected investigation e.g. iron study, Coombs’ test, B12, folate, etc in all anemic patient is “wasteful, unwise, and unnecessary”

! An accurate diagnosis can be made with minimal cost and trouble to the patient if the investigations are made logically and orderly.

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Importance of blood smear

! A 17-year old male ! With acute appendicitis

! Planned surgery

! CBC: leukocytosis platelet 5,000/uL

! No bleeding seen

Importance of blood smear

! A 18-year old male ! With acute fever, chill, jaundice

! CBC: Hb 7 g/dL, Hct 20% WBC 15,000, PMN 70% platelet 50,000/uL

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Importance of blood smear

! A 30-year old female ! With subacute fever, chill, fatigue, and bruising

! CBC: Hb 6 g/dL, Hct 17% WBC 15,000, PMN 50% platelet 30,000/uL

Importance of blood smear

Case A Case B

! A 34-year old male ! A 64-year old male

! With loss of appetite, upper ! With fever, weight loss, and abdominal discomfort multiple bruising

! CBC: Hb 11 g/dL, Hct 33% ! CBC: Hb 7 g/dL, Hct 21% WBC 150,000, PMN 50% WBC 150,000, PMN 20% platelet 300,000/uL platelet 30,000/uL

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Importance of blood smear Case A Case B

Importance of blood smear

! A 70-year old female ! With fatigue, syncope

! CBC: Hb 6 g/dL, Hct 10% WBC 10,000, PMN 70% platelet 200,000/uL

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Importance of blood smear

! A 20-year old male ! With fever, fatigue, bruising

! CBC: Hb 7 g/dL, Hct 20% WBC 14,000, PMN 90% platelet 50,000/uL

Importance of blood smear

! A 20-year old male ! With fever, fatigue, bruising

! CBC: Hb 7 g/dL, Hct 20% WBC 14,000, PMN 90% platelet 50,000/uL

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CBC’s critical values

Parameters Less than Greater than Hb (g/dL) 7 WBC (cells/uL) 1,000 50,000 Platelet (/uL) 50,000 1,000,000

Harrison’s Principal of Internal Medicine. 18th edition.

What to do with critical values

! Repeat analysis with same specimen: excluding analytical error ! Confirm with blood smear ! Check the patients’ clinical status ! If correspond: treat accordingly ! If discordant: repeat analysis with newly drawn specimen – to exclude other pre-analytical error

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Sources of error

! Pre-analytical

! Test selection ! Inappropriate test for clinical need ! Lack of clinical usefulness ! Test order not communicate ! Important information not provided ! Delayed transportation

Harrison’s Principal of Internal Medicine. 18th edition.

Sources of error

! Pre-analytical ! Specimen collection ! Incorrect time of collection ! Patient not prepared ! Incorrect specimen ! Incorrect specimen container ! Insufficient specimen ! Contaminated by fluid, bacteria, drugs ! Specimen mislabeled

Harrison’s Principal of Internal Medicine. 18th edition.

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Sources of error

! Analytical

! Incorrect storage condition ! Specimen misidentification ! Wrong test performed ! Assay interferences ! Assay failure

Harrison’s Principal of Internal Medicine. 18th edition.

Sources of error

! Post-analytical

! Delay communication of test result ! Results not communicate to correct person ! Incorrect result communicated ! Misinterpretation of results

Harrison’s Principal of Internal Medicine. 18th edition.

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Clinician’s expectation

! Accurate test results ! Timely result

! Good communication

Barriers between clinicians and laboratorians need to be broken.

Clinician’s expectation

60 Expected Hb turnaround time for clinicians and 50 laboratorians 40 30 20

Participants, % Participants, 10 0 10 20 30 40 50 60 >60 Time, minutes Surgeons Internists ED physicians All clinicians Laboratorians Howanitz PJ, Cembrowski GS, Steindel SJ, Long TA. Physician Goals and Laboratory Test Turnaround Times. Arch Pathol Lab Med. 1993;117:22-28.

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Clinician’s expectation

Interinstitutional turnaround time Number of Turnaround time (mins) at percentile Analysis institution observation 10th 50th 90th Hemoglobin 727 42,922 41.0 25.0 15.0

Howanitz PJ, Cembrowski GS, Steindel SJ, Long TA. Physician Goals and Laboratory Test Turnaround Times. Arch Pathol Lab Med. 1993;117:22-28.

Clinician’s expectation Percent of clinicians and laboratorians whose Hb TAT goals are met Specialty number percent Clinicians • Emergency medicine 1756 48.5 • Internal medicine 390 31.3 • Surgery 195 23.1 • Pediatrics 85 29.4 • Obstetrics/gynecology 78 28.2 • Other 72 37.5 Laboratorians • TAT 496 24.0 • Intralaboratory TAT 589 35.8 This study TAT: time from phlebotomy to result reporting Howanitz PJ, Cembrowski GS, Steindel SJ, Long TA. Physician Goals and Laboratory Test Turnaround Times. Arch Pathol Lab Med. 1993;117:22-28.

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Turnaround time definition

Lab Analysis Report accession

Intralaboratory turnaround time

Lab Lab requested Phlebotomy Analysis Report accession

Turnaround time definition Percentage of clinicians’ definition of laboratory turnaround time Specialty Test ordering Phlebotomy Report Physician Result charted receipt 35.9% Emergency Department 35.4% physician 17.6% 34.2% Internal Medicine 26.7% 25.1% 32.1% Surgery 29.9% 26.3% 34.8% Overall 32.6% 20.9% Howanitz PJ, Cembrowski GS, Steindel SJ, Long TA. Physician Goals and Laboratory Test Turnaround Times. Arch Pathol Lab Med. 1993;117:22-28.

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Conclusion

! CBC: basic, low cost, with considerable info ! Blood smear: crucial in helping diagnosis and cost saver

! Good communication between clinician and lab: improving performance, patient safety, CQI

! Turnaround time: mutually defined

Thank you for your attention Question?

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