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Anemia in Pregnancy. Presenter: Dr. Imran Khan Moderator: Prof. Chandralekha. www.anaesthesia.co.in anaesthesia.co.in@gmail.com. Definition Classification Hematological changes in pregnancy Problems related to Anemia Anaesthetic considerations. Definition.
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Anemia in Pregnancy Presenter: Dr. Imran Khan Moderator: Prof. Chandralekha www.anaesthesia.co.inanaesthesia.co.in@gmail.com
Definition • Classification • Hematological changes in pregnancy • Problems related to Anemia • Anaesthetic considerations
Definition • Anemia - insufficient Hb to carry out O2 requirement by tissues. • WHO definition : Hb conc. 11 gm % • CDC definition : Hb conc. < 11gm % in 1st and 3rd trimesters and < 10.5 gm% in 2nd trimester • For developing countries : cut off level suggested is 10 gm % - WHO technical report Series no. 405, Geneva 1968 Centre for disease control, MMWR 1989;38:400-4
Increased mortality figures Figures are consequences of the reduced oxygen transport due to anemia
WHO Classification of Anaemia Degree Hb% Haematocrit (%) Moderate 7-10.9 24-37% Severe 4-6.9 13-23% Very Severe <4 <13%
Magnitude of Problem • Globally, is about 30 % • In developing countries & India, incidence is around 40 – 90%. • Responsible for 40% of maternal deaths in third world countries. • Important cause of direct and indirect maternal deaths - Vitere FE Adv Exp Med Biol 1994;352:127
Relation b/w symptoms of anemia to the hemoglobin level Varat 1972 and Linman 1968
¯Temp, CO2 , 2-3 DPG; pH (favors loading) 100 P50 P50 80 60 Temp, CO2 , 2-3 DPG; ¯pH (favors unloading) %Saturation 40 20 0 20 40 60 80 100 PO2 (mmHg) Oxygen Transport Bohr Effect
Physiological Changes • Blood volume increases +1500 ml • RBC 450 ml • Plasma 1000 ml • Increase starts in the first trimester and gradually rises • Increased erythropoiesis but since more plasma is produced, a relative decrease in Hb and PCV • Iron stores +/- 500 mg • Iron requirements +/- 800 mg [500 mg for mother; 300 mg for fetus]. Hence need for supplementation • Hypercoagulable state increased risk of thrombosis
PROBLEMS RELATED TO ANAEMIA.. • OXYGEN AVAILABLE TO TISSUES • MANNER IN WHICH BODY COMPENSATES
COMPENSATORY MECHANISMS • Increase in CO • Rightward shift of ODC • Decrease in blood viscosity • Increase in 2,3-DPG concentration in RBC • Release of renal erythropoietin leading to stimulation of erythroid precursors in bone marrow
Symptoms Irritability Palpitation Fatigue Weakness Infection Dizziness
Signs Clinical Features Pallor of skin And m/m Soft ejection systolic murmur Edema Tachycardia Platynychia Koilonychia Glossitis Stomatitis
Causes of Anaemia Physiological anaemia of pregnancy • Nutritional-• • Iron deficiency Anaemia • Folic Acid deficiency anaemia • Vitamin B12 deficiency anaemia • Infections- Malaria, hookworm infestation, etc • Haemorrhagic- Acute or chronic blood loss • Bone marrow suppression- Aplastic anaemia, drugs, • Renal disease • Genetic - haemoglobinopathies – sickle cell disease, thalassaemia Acquired
Physiological Anaemia • Caused by pregnancy changes • Hb can vary from 10.0-14.5 g/dl • “Pathological” anaemia usually defined as Hb level <10.5 g/dl
1 Iron Absorption Amount of iron in the body Skin Urine 1-2mg/d Iron Loss Feces Menstruation 20-30mg/c Iron Requirement
Iron Requirement During Pregnancy 32 to 40 weeks 20 to 32 weeks 6.8 mg / day Early Pregnancy 5.5 mg / day 2.5 mg / day TOTAL 800 – 1000 mg RBC =500mg Fetus+Placenta =450mg Third stage blood loss =200mg Total = 1150mg
Reason For Increased Incidence Of Anemia • Poor pre-pregnancy iron balance • Improper supplementation • Repeated childbearing • Lack of awareness and illiteracy • GI infections and infestations
ANAESTHETIC CONSIDERATIONS • Elective LSCS - • Emergency LSCS - Blood Transfusion Not a Day before Surgery Fresh ( 2, 3 DPG 24 HRS. ) • Chronic, Well compensated- Hb upto 8 gm% Safe • Avoid Hypoxia ( ↑ Fi O2 ) , Maintain C V S Stability • Avoid Hypovolemia and Aortocaval Compression • Minimize - • Lt. O D C • Hyperventilation • Alkalosis • Hypothermia • ↓ 2, 3 DPG • Monitor- Complications like CCF & Shock
CHOICE OF ANAESTHETIC TECHNIQUE • Regional Anaesthesia - • Safe - Hb > 9 gm% OR 8 gm% No Cardiac Decomp. • Avoid - • Hb < 8 gm % , • Hemostatic Abnormalities, • Megaloblastic Anemia • Precautions - Fi O2 , Low Dose L. A. + Opioid • Disadvantages - Preloading - Sympath. Block Ppt. Hypotension
ADVANTAGES OF REGIONAL ANAESTHESIA • Mother is aware of Child Birth • Less blood loss • Analgesia can be extended post op period • No risk of Aspiration • No risk of Complications d/t intubation and drug induced S/E
EPIDURAL V/ S S.A.B. • Adv. Of Epidural - Less precipitous fall in B>P - Post Op Analgesia • Disadv. Of Epidural - Time Consuming - L.A Toxicity. - Patchy, Inadeq. Blocks • Adv of SAB. - Easy Rapid onset with High Success Rate - Small Vol. of drug Less Toxicity - low dose L.A + Opioid » Less Hypotension » Intense surgical Anaesthesia. » Post op analgesia - Fine bore needle No P.D.P.H.
C. S. E. • S.A.B. - Speed of Onset - Reliability - Low Toxicity + • Epidural Catheter - Control of Height of Block - Supplement Inadeq. Block - Post Op Analgesia
GENERAL ANAESTHESIA • choice - If Hb = 8 gm % with cardiac decomp.. - Hb < 8 gm % • Adv. - Rapid Induction - less hypotension and better CVS. stability - Control of Airway and Ventilation - Severe Anemia Post op Ventilatory Support - No Anxiety of being Awake • Disadv. -Failed Intubation - Gastric Aspiration
G. A. TECHNIQUE • Supine with wedge under right hip • Pre oxygenation • Thio+ Sux/Roc. • Problems - Safe cricoid pressure - Failed Intubation - Awareness - Neonatal Effects » I. D. I. > 8 MIN. » U. D. I. > 3 MIN. • Severity of anemia- Post Op Ventilation
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