WELCOME YOU ALL FACULTY MEMBERS AND FRIENDS OF THE DEPTT. WONDERFUL PROCESS STARTED BY OUR DEPARTMENT HAPPY NEW YEAR WITH SLOWLY ENTERING INTO 2013

ESTIMATION OF BLOOD LOSSProf: Anil OhriDEPARTMENT OF ANAESTHESIA INDIRA GANDHI MEDICAL COLLEGE,SHIMLA-171001

INTRODUCTIONWHY ESTIMATION OF BLOOD LOSS ….?

•Blood loss Threatening Fatal Problem. Blood losses>20-30%(total blood),Body Unable To Adjust Consequently Causes Failure in Multi-organ Functions. Not Treated in time, Lead Irreversible Functions Losses.

•Surgeon Usually Estimate at theEnd By Seeing Blood-Suction Container and Surgical sponges. Underestimated.

•Medical Personnel to EstimateAccurately. Under or Over Estimation-Delayed or Excessive Unnecessary Transfusion.

PROBLEMS WITH MEASUREMENTS• Common Reason Cited For underestimation loss is

blood loss looked upon unfavourably.*Many Techniques Devised –Estimate Accurately, Includes –Mathematical Model, Photometric Method,Cell Counts on blood loss. Methods Time consuming, Impractical,& Expensive.

IMPACT OF WRONG ESTIMATIONInaccurate Estimates Adversely Affects Well Being - intra- and postoperative care.

Decision –Transfusion After Considering - complications,symptoms, HB Level ,Hematocrit Level, & Amount of Surgical Loss as well

COMPONENT IMPORTANT FOR OXYGEN DELIVERY TO TISSUES•Four Components viz. Hb%, SpO2, Cardiac output and Hb-O2 affinity, also Hematochrit determines Quantity of O2, Available for Bodily Functions.

•Hb% (only component can be augmented easily) Pre-operatively for Enhancing Availability of O2 and is basis for Pre-operative Hb% Estimation.

DETERMINANTS OF OXYGEN DELIVERY1.Pulmonary Gas Exchange

2.Cardiac Output

3.Blood Oxygen Contents

4.Hb-Oxygen afiinity

5. Oxygen consumption

Oxygen Extraction Ratio=Art O2 -Mix VO2/A O2

IMPOTANCE OF HAEMOBLOBIN BEST EVIDENCE ANAESTHESIA REPORTS (BEARs) IS IT NECESSARY TO ESTIMATE HAEMOGLOBIN LEVEL ROUTINELY PRIOR TO SURGERY ?(Dr. Kotur. P. F.)(IJA,April,2006)

Ott and cooley ,1977 reported study of 542 cases in Texas without transfusion cardiac surgeries and reported that 51 patients died out of which 12 were related to pre or post operative anemia,3,died due to blood loss.

PRE-REQUISITS FOR ESTIMATING BLOOD LOSS

Measurement Of HaemoblobinMeasurement of PCV and Or Hct(F=39-40%&M=39-49%)

Measurement of Blood VolumeEBV(Lt)=0.0248xH0.725xW0.425-1.954(Female or 55-65ml/kg)

EBV(Lt)=0.236xH0.725xw0.425-1.229 or Males 60-75ml/kg

METHODS OF ESTIMATING BLOOD LOSS1.Measurement of HB%

2. Measurement Of PCV &or HCT%

3.Subjective Method

4.Gravimetric Method5. Calorimetric method

7-10 gm%. Simple can give us rough estimates pre & or postoperatively. Mortality related with Hb<6gm%-mortality 61.5%;7.1% if 10 gm% or more.by CARSEN JL etal,1988 reported in severity of Anaemia &operative mortality morbidity,TEXAS.

1. Measurement of Hb%

Constitution OF Blood (B)

Hematocrit 45 ± 7 (38–52%) for males

42 ± 5 (37–47%) for females pH 7.35–7.45 base excess −3 to +3 PO2

10–13 kPa (80–100 mm Hg) PCO2

4.8–5.8 kPa (35–45 mm Hg) HCO3

−

21–27 mM Oxygen saturation Oxygenated: 98–99%

Deoxygenated: 75%

Gas Exchange In The BODY(C)

HB-O2 Dissociation Curve(D)

2.Measurement OF PCV & or Hct % (A)

Allowable Blood Loss (ABL)* EBV x (Hi - Hf)Hi = ABL Blood volume

Hi = initial Hct Blood volume  Normal Hct Values*** Men 42-52% Women 37-47% Hf = final lowest acceptable Hct  Estimated Blood Volume (EBV)EBV = weight (kg) x average blood volume Average blood volumes**Age

(B)PCV & or HCT% constitutes the important factor in maintaining the viscosity

With loss of RBC the viscosity decreases and proteins are also lost then it decreases further.

In animal studies-1% loss of blood associated with 1.8% decrease in cardiac output.(POVEK&CARY IN 1974) Mortality and morbidity associated with blood loss(500ml or less-8% and 42% if>2000ml).

If previous formula applied to a standard person the allowable blood loss comes to about 1083ml

Allowable Blood Loss(C)

Normal Blood Vol.&HCT(D) Premature Neonates

95 mL/kg Full Term Neonates

85 mL/kg Infants

80 mL/kg Adult Men

75 mL/kg Adult Women

65 mL/kg Normal Hct Values*** Men

42-52% Women

37-47%

3. Subjective Measurement Of Blood Loss

Cheap,Continuous &Unreliable Difficult to Assess Loss 500ml to 1500 ml as under,Don’t

use in Cardiac, Trauma or pediatric surgery as loss of blood in tissues One should know allowable blood loss. MORTALITY RATES ARE HIGHER IF BLOOD NOT REPLACED.

Blood Loss measured by Surgeon is usually inaccurate

(Comparison of Subjective Estimates by Surgeons and Anaesthetists of Operative Blood Loss

By AE Delikan Concluded :That it is Mutual decision by the anaesthetist &Surgeon STUDIED 100 CASES)

4.GRAVIMETRIC METHODA) WEIGHING OF PATIENT: Operation Table Available To

Measure Pre and post Surgery Weight Accuracy +- 10 G.

Inaccurate. Good Check On other Methods.

B) WEIGHING SWABS: Simple & Commonly Used.

Bloss Measured in GAIN Of Weight Of Swab &Towels Together with Contents of Bottle 1ml of Blood=1Gm of

swab ;Underestimation of 25%. Source of Error SP GR RBC-1.0293 ;Sp Gr Plasma-1.0270,

Neither Precise Nor Accurate Assessing Gravimetric Estimation of Intraoperative Blood Loss RAVI S. JOHAR and ROGER P. SMITH. Journal of Gynecologic Surgery. Fall 1993, 9(3

C)Modified BY Bonica & Lyter 1951 Using saline for comparison

5.COLORIMETRIC METHOD

Towels,Swab mixed with large known Vol of Fluid(Added Ammonium Hydroxide1:1000+defoaming Agent) Which is then estimated colorimitrically.

Error: Contamination Or Bile Mixed Prerequisite: Preoperative HB%;Weighing Of Patient if Complex ExChanges expected inBlood

Blood Loss(ML)=Colorimetric Reading(Hb%)xVol Of sol -----------------------------------------------------

200(Dilution Factor)XPatients Hb%

(ESTIMATION OF BLOOD LOSS DURING SURGERY J. A. Thornton Ann R Coll Surg Engl. 1963 )

6.RADIOACTIVITY OF BLOOD)

Measuring the activity on blood in swabsInject known ammount of Radioactive dye Time cosuming,Costly Apparatus and leakage are the problem.If albumins are tagged then Leak in Non vascular Compartment.If RBCs then has to be tagged preopratively.

Advantage : No over Previous Methods.

7. MEASUREMENT OF LOSS BY SUCTION

Meaured Jars Can be used IN The Operation Theatre

Using Defoaming Agent In The Jar.

8.VISUAL COMPARATIVE COLORIMETRY: Simple to use in OTDoes not require preoperative HB/HctColor of two solutions are compared.does not depend on LaboratoryWe Prepare two Solutions ------------------------------------CONTD.

8.VCC(A)Sol.-A- 5ml pt blood in HEPARINISED Syringe Make it

1% in Water(1%=0.15%Hb)Sol.-B-Washing OF All type Blood and Prepare a Sol. Till

its Color match with A.Take it in 10ml Syringe.Sol.C-This syringe contain 9ml of water From Original patient Sample 10% solution made and

filled in Insulin Syringe and drop wise added in Sample tube-B-Compare both Sol for color Match in X-ray view box.Ammount of blood requiered to bring match Noted(Vb): Vol Of Sample(10 ml);Vol of Diluent(Vd)

OBL=Vb/VcxVd=MlSimilar sample to Lab for blinding and Color in

Spectrometry Error1-2%

9.Plastic Bag CollectionUse of a transparent plastic collector bag for

estimation of blood loss in the third stage of labour:

a cluster randomised trial (This protocol follows the recommendations for reporting randomised controlled trials

described withinEUPHRATES-Protocol-C-RCT-11-2005-approved by Collaborators meeting

8. USE OF iPAD CAMERAS AND ALGORITHM TO ESTIMATE BLOOD LOSS

“Gauss Surgical Inc.’s mobile medical platform uses the iPad to scan surgical surfaces that are covered in blood — namely, pieces of gauze that soak up blood during surgery. Through an iPad app, those scanned images are sent to the cloud, where Gauss’ algorithms go to work, ‘almost like facial recognition software,’ to determine and deliver an estimate of how much blood is present in that sample, said co-founder and chief technology officer Siddarth Satish.”

The iMedical Apps team has discussed the myriad of ways the iPad may be a game changer in the OR, and this is another tool to add to the list. If you combine this with the disposable sterile iPad sleeve for use in the operating room exclusive we brought to you first, you would further the utility of the platform.

Furthermore, if this new methodology is shown to be superior, it may be incorporated into the routine of the OR.

COMPARISON AND BEST REPLACEMENT METOD

Baronofsky et al 1946,said gravimiteric and Colorimetric

Methods are Comparable and One should Adopt Swab Method For Measuring Blood Loss.Add persipiration,Drapes loss,Loss of water and 25% of Loss is equal to true operative loss.But blood lost in operative site and tissues can not be measured.

BEST METHOD Of REPLACEMENT is replace blood as lost. Replace Whole blood,540ml (Stored Bl) has 440ml of Whole blood. Use Of Labels While Trasfusing The blood.

BEST METHOD OF REPLACEMENT(A)

BEST METHOD OF ADMINISTRATION(B) Perioperative complications (on the 'Y' axis) decreasing with increasing volume

load (on the 'X' axis) up to a critical point (optimal level). Hypovolaemia leads to tissue underperfusion, suboptimal organ function,

organ failure, and death. (Perioperative fluid therapy: How much is not too much?CL Gurudatt-2012)

FUNCTIONS cardiac function, pulmonary function, tissue oxygenation, wound healing, postoperative ileus, renal function, and coagulation may all be influenced by perioperative fluid administration.

Goal-directed fluid management guided by flow-based haemodynamic monitors decreases postoperative complications in major surgeries.

FUTURE IMPORTANCE To EDUCATE THE WHOLE STAFF IN THEATRE ABOUT

ASSESSING BLOOD LOSS. Training Schedule for the Medical students to learn about Blood

loss and its Importance Review and Clinical Material For Teaching About Blood loss by the

article belowREF.BLOOD LOSS: CLINICAL TECHNIQUES FOR ONGOING QUANTITATIVE MEASUREMENT(Audrey Lyndon, PhD, CNS, RNC, Department of Family Health Care Nursing, University of California, San Francisco; Suellen Miller, PhD, CNM, MHA, Department of Obstetrics;Gynecology and Reproductive Sciences, University of California, San Francisco; Valerie Huwe;RN, BSN, El Camino Hospital; Mark Rosen, MD, Department of Anesthesia, University of California, San Francisco; David Lagrew, MD, Saddleback Memorial Medical Center; PatriciaDailey, MD; Anesthesiology, Mills Peninsula Health Services; Elliott Main, MD, Department of OB/GYN, California Pacific Medical Center, Sutter Health)

Thankyou