ESR AND CRP IN ESR AND CRP IN ORTHOPEDICSORTHOPEDICS

SuhasSuhas

►They are known as acute phase They are known as acute phase reactantsreactants

►They reflect the acute phase response They reflect the acute phase response to local and systemic inflammatory to local and systemic inflammatory response.response.

Causes or StimuliCauses or Stimuli

► Infection , Infection , ► injury or trauma, injury or trauma, ►Surgery,Surgery,►Hypoxic injury, Hypoxic injury, ►thermal injury, thermal injury, ►allergic reaction,allergic reaction,►malignancy .malignancy .

Other acute phase reactantsOther acute phase reactants

►haptoglobin, haptoglobin, ►Ceruloplasmin,Ceruloplasmin,►fibrinogen, fibrinogen, ►Prothrombin,Prothrombin,►Complement components (C3, C4, C5, Complement components (C3, C4, C5,

etc.). etc.).

Why CRP and ESRWhy CRP and ESR

► increase in concentration relatively increase in concentration relatively high compared to basal concentration high compared to basal concentration

►relatively short lag time from the relatively short lag time from the moment of stimulus moment of stimulus

►cost-effective cost-effective

CRPCRP

►Discovered in 1930Discovered in 1930►Till 1970 only qualitative estmation after Till 1970 only qualitative estmation after

that now its quantitative estimation.that now its quantitative estimation.►Synthesized in the liver by hepatocytesSynthesized in the liver by hepatocytes►Cytokines IL-6 induces the synthesis of Cytokines IL-6 induces the synthesis of

crp.crp.►The clearance rate of CRP is constant.The clearance rate of CRP is constant.

►therefore the level of CRP in the therefore the level of CRP in the blood is regulated solely by blood is regulated solely by synthesis. synthesis.

►The plasma levels of CRP 1 mg/L with The plasma levels of CRP 1 mg/L with normal being <10 mg/L.normal being <10 mg/L.

► levels begin increasing 4-6 hr after levels begin increasing 4-6 hr after initial tissue injuryinitial tissue injury

►Doubles every 8-9 hr exponentially.Doubles every 8-9 hr exponentially.►Returns to normal with restoration of Returns to normal with restoration of

tissue structure and function. tissue structure and function.

ESRESR► It’s a measure of the vertical column It’s a measure of the vertical column

in the westergen tube.in the westergen tube.►Response of acute phase reactants Response of acute phase reactants

increase fibrinogen in the plasma increase fibrinogen in the plasma which increase positively charged which increase positively charged RBC’S RBC’S

► Increased rouleaux formation Increased rouleaux formation thereby increasing ESR.thereby increasing ESR.

FACTORS EFFECTINGFACTORS EFFECTING► SizeSize► shape of red blood cells, shape of red blood cells, ► plasma compositionplasma composition► fluid statusfluid status► Age temperatureAge temperature► PregnancyPregnancy► drugs drugs

► CRP is independent of the physical CRP is independent of the physical properties.properties.

Clinical Significance of CRP Clinical Significance of CRP and ESR and ESR

►Predicting post-op infection before the Predicting post-op infection before the development of clinical symptoms.development of clinical symptoms.

►Common Common clinical symptoms areclinical symptoms are masked by the effects of the masked by the effects of the procedure itself.procedure itself.

►Pain, fever, tachycardia and elevated Pain, fever, tachycardia and elevated WBC can be due to surgery or WBC can be due to surgery or infection.infection.

Larsson et al Larsson et al

►Sample- 193Sample- 193►Studied the Studied the the natural CRP course for the natural CRP course for

uncomplicated surgery.uncomplicated surgery.►Once the natural CRP response after Once the natural CRP response after

uncomplicated surgery is known, then uncomplicated surgery is known, then deviation from normal should raise deviation from normal should raise clinical suspicion that a complication clinical suspicion that a complication may be surfacing.may be surfacing.

-condt-condt► 193 pts 4 types of surgeries were done.193 pts 4 types of surgeries were done.► THR, TKR, Revision Hip, discectomyTHR, TKR, Revision Hip, discectomy► CRP levels were measured days 0, 5, 10, CRP levels were measured days 0, 5, 10,

14, 21, and 42.14, 21, and 42.

► All four procedures had a peak CRP All four procedures had a peak CRP response 2 to 3 days after surgeryresponse 2 to 3 days after surgery

► biphasic rapid decline. biphasic rapid decline. ►Day 3-5 1Day 3-5 1stst decline decline►Day 14-21 2Day 14-21 2ndnd decline decline► ESR was high to 42 days, in rev hip upto 1 ESR was high to 42 days, in rev hip upto 1

year.year.

conclusionsconclusions►The conclusion from the study is that The conclusion from the study is that

a normalized CRP response that a normalized CRP response that follows a typical biphasic response follows a typical biphasic response seems to indicate an uneventful seems to indicate an uneventful recovery.recovery.

►Any deviation from the normal Any deviation from the normal response curve indicates an chance response curve indicates an chance of post op infection.of post op infection.

Mustard et al. Mustard et al.

► Study size-108Study size-108►Measured the levels of CRP pre and post Measured the levels of CRP pre and post

op.op.► Positive CRP responsePositive CRP response

- level on day 3 or 4 > 80% of day 2- level on day 3 or 4 > 80% of day 2

- after day 4, inc on two consecutive days- after day 4, inc on two consecutive days► Subjects who had postive crp response Subjects who had postive crp response

had later developed post op infection.had later developed post op infection.

Waleczek et al Waleczek et al

►Study group 107.Study group 107.►Compared esr, crp, wbc, body temp, Compared esr, crp, wbc, body temp,

clinical features.clinical features.►7 out of 107 had abnormal crp 7 out of 107 had abnormal crp

patterns and all of them developed patterns and all of them developed wound infectionswound infections

Meyer et al Meyer et al

► 400 patients underwent discectomy out of 400 patients underwent discectomy out of which 15 had post op infection and all 15 which 15 had post op infection and all 15 had crp level on day 5 was more than day 1.had crp level on day 5 was more than day 1.

►The sensitivity of CRP was thus The sensitivity of CRP was thus determined to be 100%, specificity determined to be 100%, specificity 95.8% 95.8%

Conclusion Conclusion

► CRP is better than ESR in diagnosis and CRP is better than ESR in diagnosis and monitoring treatment of infection in post op monitoring treatment of infection in post op pts.pts.

► Single CRP reading holds very limited value.Single CRP reading holds very limited value.► Trend must be observed for its usefulness.Trend must be observed for its usefulness.► CRP rises early and before the onset of CRP rises early and before the onset of

clinical symptoms, and declines with the clinical symptoms, and declines with the resolution of infection.resolution of infection.

► It is a biologic warning sign that should It is a biologic warning sign that should raise an index of suspicion for infection if a raise an index of suspicion for infection if a rising trend. rising trend.