Case Studies in Analyzing Lab Values

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Case Studies in Analyzing Lab Values

Julie Miller, RN, BSN, CCRN

Introduction

Correlate lab values to clinical patient assessment

Clues to assessment and interventions

ABG’S

pH

Acidosis 7.40 Alkalosis

7.35 - 7.45

PaCO2

Alkalosis 40 Acidosis 35 - 45 HCO3¯

Acidosis 22 - 26 Alkalosis

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Uncompensated pH Uncompensated

Acidosis < < 7.35 -7.40 - 7.45 > > Alkalosis

Compensated Compensated

Acidosis AlkalosisAcidosis Alkalosis

7.40

pH First Name: Compensated or

Uncompensated

Last Name: Acidosis or Alkalosis

Identify PaCO2 & HCO3¯ Acidosis or Alkalosis

Middle NameMatch PaCO2 to pH for respiratory

Match HCO3¯ to pH for metabolic

Use the ph to obtain first and last names

pH: 7.20, PaCO2: 74, HCO3¯: 26

Fi t N L t NFirst Name Last Name

Uncompensated Acidosis

Use PaCO2 and HCO3¯ to obtain middle name

Middle Name

Respiratory

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First Name Middle Name Last Name

pH: 7 20 PaCO : 74 HCO ¯: 26 pH: 7.20, PaCO2: 74, HCO3 : 26

What conditions?Anything that causes Hypoventilation

First Name Middle Name Last Name

¯ pH: 7.52, PaCO2: 32, HCO3¯: 24

What conditions?Anything that causes hyperventilation

pH: 7.18, PaCO2: 35, HCO3¯: 12

What conditions?What conditions?Renal Failure, DKA, Diarrhea, Lactic Renal Failure, DKA, Diarrhea, Lactic acidosis, Ethylene Glycol, Drugs such as acidosis, Ethylene Glycol, Drugs such as Epinephrine, ASAEpinephrine, ASA

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pH: 7.56, PaCO2: 45, HCO3¯: 34

What conditions?What conditions?NGT Suction, Hyperemesis, Antacid NGT Suction, Hyperemesis, Antacid abuse, Bicarb Drips, THAMabuse, Bicarb Drips, THAM

Base Excess or Deficit Calculated using pH, PaCO2 & HCT

Normal: -2 - +2 mEq/L

Negative = Metabolic Acidosis

Positive = Metabolic Alkalosis

Bicarb = One half the buffers in blood

Lactic Acid Normal Values

mEq/L

Venous: 0.5 – 2.2

Keys to Collection Avoid hand clench

Avoid tourniquet

Arterial: 0.5 – 1.6

Indicates? Shock state

Anaerobic metabolism

Place on ice

Discard if more than 15 minutes old

Predictor of mortality

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Anion Gap

Normal 12 + or – 4 mEq/L 5 – 11 mEq/L or 8 – 16 mEq/L Check your Labs Normals

Calculated (Na + K) (Cl + HCO ) (Na + K) – (Cl + HCO3)

Reflects Amount of Other Anions NOT Routinely Measured Phosphates Sulfates Ketone Bodies Proteins Lactic Acid

Anion Gap High Anion Gap Acidosis

Increased Production of the Anions DKA

Non –Anion Gap Acidosis Loss of Bicarbonate

Retention of Chloride ions Diarrhea DKA

Lactic Acidosis

Rhabdomyolysis

Poisonings Methanol

Salicylate

Ethylene Glycol

Use of Acetazolamide Therapy

Total Carbon Dioxide

Normal: 22 -30 mEq/L

What other lab has similar normals?

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Total CO2 SMA-7Na: 142

K+: 3.9

ABGpH: 7.33

PaCO2: 35K : 3.9

CL: 102

CO2: 22

Bun: 21

Cr: 0.5

PaCO2: 35

PaO2: 74

HCO3: 21

SaO2: 92%

CBC HGB, HCT, & PLT

WBC Differential

Left and Right shift

ANC

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CBC HGB:

Females: 12 - 16 g/dl

Males: 14 - 18 g/dl

Newborns: 15.5 – 24.5 g/dl

Infants: 9.0 – 15.5 g/dl

HCT: Females: 37 - 47 %

Males: 40 - 54 %

Children: Varies by age

CBC Increased H/HAltitudeDehydration

Decreased H/HHemorrhageHypervolemiaDehydration

Chronic hypoxiaSmoking, COPD

CHFDrugs:

Gentamycin

HypervolemiaPregnancyHemolysis

IABPDrugs: Indocin

and antibiotics

Renal Failure

CBC Platelet count

Adults: 150 000 -

Heparin effect?

Adults: 150, 000 -400,000 μ l or mm³

Newborns: 100,000 –300,000

Infants @ 3months

Increased levels?

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Case Study

64 y.o. M. FUO, s/p IMI on IABP & Epi

HGB 11.4, HCT 34, PLTHGB 11.4, HCT 34, PLT 84,000, WBC 18,000

CRP 18 mcg/ml

pH: 7.32, PaO2: 92, PaCO2: 35, HCO3¯: 20

What’s going on?

CBC & Differential

WBC = LeukocytesMales and Females: 4500 - 11,000/μl

Children: Newborns: 9,000 - 30,000/μl

Gradually decreases to adult level by 10 y.o.

Differential Granulocytes Neutrophils:

Bands 3 - 6 % (infants 5 – 11%)

Segs 50 – 62 % (infants 15 – 35 %)

Eosinophils 0 – 3 % Allergic Disorders and Parasitic Infections

Basophils 0 – 1 % Chronic Inflammation and allergic disorders

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Differential Monocytes 3 – 7 %

Phagocytosis: Cellular debrisProduce interferon (antiviral)

Lymphocytes 25 – 40%T and B Cells

B Cells = Antigen/Antibody T Cells = Master Immune Cells

Differential

Neutrophils: Illustrated from left to right

Young cells on left more mature to right Young cells on left more mature to right

Bands Segs

ANC Absolute Neutrophil Count

(%Segs + %Bands) X WBC

{Percentage expressed as decimal}

Indicates? Neutropenic Less than 1500 – 2000/mm3

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ANC - Nursing Implications

Neutropenic Precautions

Universal Precautions

No Rectal Temps meds or exams No Rectal Temps, meds or exams

Minimize Invasive Lines and Tests

Prevent Tissue Breakdown

Meticulous Oral Care

Limit Visitors to HEALTHY

Case Study 42 y.o. F metastatic breast CAWBC: 1500

B d 40 %Bands: 40 %

Segs: 25%

What is her ANC?

Case Study 42 y.o. F metastatic breast CAWBC: 3200

B d 20 %Bands: 20 %

Segs: 10%

What is her ANC?

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Potassium

Normal:

3.5 - 5.3 mEq/L

K+ K+

K+ K+

K+ K+

Hyperkalemia Serum level > 5.3

Causes: K+ K+K+ K+

H+ H+ H+ H+

Causes:Crush injury

Acidosis

Renal failure

K+ K+ K+ K+

K+ K+ K+ K+

K+ K+ K+ K+

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HyperkalemiaCardiac changes> 5.5 Peaked T waves

Hyperkalemia> 6.5 Prolonged PR and small P

waves

>7.0 Widened QRS Tall T wave

Hyperkalemia> 8.0 Widened QRS, Sine waves

Varies by patient progresses to asystole

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Hyperkalemia Treatment

K+ K+

Serum level > 5.3

Protect the heart

Hide the K+

K+ K+ K+ K+

Hyperkalemia Protect the Heart

Calcium Chloride or gluconate

Excrete the Potassium

Hide the Potassium Insulin and glucose

Na Bicarbonate

Sodium polystyrene sulfonate

Diuretics

Dialysis

Case Study 63 y.o. F. Diabetic, Chronic renal failure, HX of

cardiac disease

Found semi-conscious and bradycardic

Transferred to ICU, Labs pending

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Case Progression

Case Progression History obtained:Patient kept bottle of Salt Substitute at

bedsideN i I li tiNursing Implications

Case Conclusion

Hypokalemia Serum levels < 3.5

Causes:

Treatment Protect the Heart!

Causes:Diuresis

Gastric loss

Insulin

NaHCO3¯Replace losses

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Hypokalemia

Case Study

54 y.o. M c/o 3 day history of diarrhea and vomiting.

Has continued lasix tablets but stopped KCL because it upset his stomach

Case Study

Guess the potassium?Guess the potassium?

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Case Study

Potassium: 1.8 mEq/Liter

Treatment? Treatment?

What other dysrhythmias?

What acid/base disturbance?

Case Study Hypokalemia

If you wait to treat!

Magnesium

Normal: Normal:1.2 - 2.9 mEq/L

K+ K+

Mg++ K+

K+ Mg++

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HypomagnesemiaSerum level < 1.2 mEq/L

Symptoms: Muscle tremors

Nausea

Cardiac dysrhythmias?

Case Study 44 y.o. M

Hx. Of gallstones

Pre op for gall

4 day hx of diarrhea and vomiting

Pre-op for gall bladder removal

diabetic

C/O C.P.

Case Study

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Hypermagnesemia Serum level > 2.9 mEq/L

Symptoms: Respiratory depression

ECG is similar to hyperkalemia

Sodium

Normal Serum Levels:Levels:

135 -145 mEq/L

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Hypernatremia Causes:DI, Dehydration – Water loss

Drugs: ie Na BicarbonateDrugs: ie Na Bicarbonate

S & Sx: Confusion to coma

Febrile, Tachycardic

Hypernatremia

Serum Labs HypernatremiaOsmolality elevated

•Dehydration•Almost Always

Osmolality elevated Hypokalemia

Urine Labs Hyponatremia Low osmolality

Hypernatremia

Sodium stays in body with massive fluid loss

Clues Urine Sodium Low with

Volume losses – DI

Urine Sodium HIGH with renal Na loss with osmotic diuresis ie with DKA

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Hypernatremia

General Treatment Isotonic Fluids for

Vascular Space –Maintain

Monitor for Volume Overload Lung and Heart

SoundsMaintain Hemodynamic Stability

Hypotonic Fluids for Interstitial and Intracellular Replacement May Match UOP

Sounds Peripheral Edema

Check Albumin Levels

Monitor Sodium Correct Slowly!!!

Case Study 52 y.o, s/p subarachnoid

hemorrhage

800 ml of urine over last hour -Clear Pale YellowClear Pale Yellow

Serum Sodium 148

Urine Osmolality 200 mOsm/kg

What is this?

Diabetes Insipidus

Hyponatremia Causes:Dilutional

SIADH, CRF, DM, Water intoxicationintoxication

Salt Wasting Syndromes DKA, Water Intoxication

Atrial Natriuretic Peptide

ACE Inhibition

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Hyponatremia

SIADH –Syndrome of Inappropriate ADH

S A“Swimming In” ADH Excess Secretion from Post. Pituitary

Excess ADH Decreased UOP

Water Retention – Volume Overload

Dilutional Hyponatremia

Hyponatremia Salt wastingAtrial Natriuretic Factor

Hormone produces sodium excretion Associated with Neurologic damage

Results in: High urine output Low serum sodium Water loss = Dehydration

Decreased CVP & PAOP

Hyponatremia Treat Underlying

CauseSIADH

S & SxHeadache, muscle

cramps, confusion, SIADH

Fluid Restrict, Diuretics, Hypertonic Saline

Salt Wasting Isotonic Fluid

Replacement

Hypertonic Saline

Tachycardia, Seizures

Dilutional Increased CVP & PAOP

Saline Loss Volume Loss

Decreased CVP & PAOP

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Case Study 56 y.o. F Bronchogenic

Oat Cell Carcinoma, Ventilator Dependent –Trach, Confused.

Decreased urine output Urine Osmolality HIGH

Serum Na: 132 What is this?

SIADH due to Positive Pressure Ventilation

Differentiating

SIADH Salt Wasting

DI

Too Much ADH ANP related to HHH

Too Little ADHHHH

Low Serum Na Low Serum Na High Serum Na

Low UOP High UOP High UOP

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Integrate 58 y.o. Male, diabetic

Pre-op for Thoracotomy

New onset Atrial New onset Atrial Fibrillation

On Enoxaparin for DVT prophylaxis

Integrate

ABG’s:pH: 7.28

PaO2: 88

PaCO2: 35

HCO3¯: 16

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Integrate CBCWBC: 18,000

Hgb: 18.5

ChemistryGlucose: 225

Hgb: 18.5

HCT: 52

Platelets: 76,000

TSH: 0.3 μU/ml

Potassium: 3.2

Magnesium: 1.9

10 y.o. F. Grade II Splenic Laceration, MVC

CVP line and hemothorax with chest tubes

ABG: pH: 7.29, PaO2: 78, PaCO2: 49,

HCO3¯: 27

WBC: 14, 500, Hgb: 8.5, HCT: 30%, PLT: 96,000

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Na: 138

K+: 3 5

BUN: 20

Cr: 0 7 K+: 3.5

CL¯: 107

CO2: 27

Cr: 0.7

Glucose: 120

26 y.o. M s/p crush injury to upper and lower extremities, CHI

Ventilator hemodynamic pressure Ventilator, hemodynamic pressure lines, chest tubes bilaterally

ABG’s: pH: 7.48, PaO2: 90, PaCO2: 32, HCO3¯: 21

Na: 148, K: 3.1

Cl 98 CO2 20 Cl: 98, CO2: 20

BUN: 44, Cr: 1.8

glucose: 187

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WBC: 15,000 Bands: 40%, Segs:

20%

Fibrinogen: 400

FDP: 35 HGB: 9.6

HCT: 31%

Platelets: 420,000

PT: 16

PTT: 38

Amylase: 280

Urine Myoglobin: Positivey g

Ionized Calcium: 1.08

Lactic Acid: 8.4

Conclusion

Evaluation of laboratory data can assist in interventions for the patient

Speaker Contact: [email protected]

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