ANAEMIA IN PREGNANCY

1. ANAEMIA IN PREGNANCY Presenter: Dr Anshuman Raheja Moderator: Dr Medha Mohta University College of Medical Sciences & GTB Hospital, Delhi www.anaesthesia.co.in email: anaesthesia.co.in@gmail.com

2. Anaemia Quantitative or qualitative reduction of Hb or circulating RBCs or both in circulation resulting in reduced oxygen carrying capacity of blood to organs and tissues. Anaemia in pregnancy Hb conc. <11 gm/dl or Hct < 0.33 in 1st & 3rd trimester Hb conc. <10.5 gm/dl or Hct < 0.32 in 2nd trimester In developing countries, limit brought down to 10 gm/dl Prevalence in India = 65 to 75 % (WHO)

3. Classification of anaemia Based on • Etiology • Morphology • Severity

4. Classification based on etiology • Physiological anaemia • Acquired anaemia • Nutrition: Iron deficiency, folate deficiency, vit.B12 deficiency anaemia • Infections: Malaria, hookworm infestation • Haemorrhagic: Acute / chronic blood loss • Bone marrow suppression: Aplastic anaemia, drugs • Renal disease • Genetic: Haemoglobinopathies • Sickle cell disease • Thalassemia

5. Classification based on morphology • Microcytic : Iron deficiency anaemia, thalassemia • Normocytic : haemolysis, acute blood loss, bone marrow disease. • Macrocytic : folate deficiency, vit. B12 deficiency.

6. Classification based on severity of Anaemia WHO CATEGORIES Category Severity Hb(gm%) 1 Mild 10 – 10.9 2 Moderate 7 – 9.9 3 Severe <7.0

7. Severity of Anaemia ICMR CATEGORIES Category Severity Hb levels gm % 1 Mild 10 – 10.9 2 Moderate 7 – 10.0 3 Severe <7.0 4 Very severe <4.0

8. Severity of Anaemia Severity Hb (gm%) Mild 8-10 Moderate 6.5-8 Severe <6.5 Clinically used in developing countries

9. Importance of topic ??? Anaemia in pregnancy • The commonest haematological disorder that may occur in pregnancy • Severe anaemia can increase morbidity and mortality in mother as well as baby

10. Complications of anaemia During Pregnancy - Pre eclampsia (due to malnutrition or hypoproteinemia) - Intercurrent infection (diminished resistance to infection) - Cardiac failure (at 30-32wks of pregnancy) - Preterm labour

11. During Labour - PPH - Cardiac failure - Shock During Puerperium • Puerperal sepsis • Subinvolution • Failing lactation • Puerperal venous thrombosis • Pulmonary embolism

12. Effects on baby Amount of Fe transferred to fetus is uneffected even if mother suffers from Fe deficiency Moderate to severe anaemia may cause - IUGR - prematurity - low foetal store of Fe/vitB12/folate - increased risk of anaemia/nutritional disorder in early infancy - still births - congenital malformations - ↑ in neonatal deaths/perinatal mortality by 2-3 fold when Hb < 8gm% and 8 – 10 fold when Hb< 5gm%

13. Role of Anaesthesiologist Anaesthetic management • Anaemic patient for LSCS • Anaemic patient for non-obstetric surgery Critical care management • Cardiac failure • Haemorrhage with shock • Pulmonary embolism

14. Physiological Anaemia of Pregnancy

15. Physiological anaemia of pregnancy Blood volume ↑45% Plasma volume ↑55% RBC volume ↑30% Hct ↓30% Hb ↓10.5-11

16. Criteria for Physiological anaemia • Hb = 10 gm% • RBC = 3.2 million/mm3 • PCV = 30% • Peripheral smear showing normal morphology of RBC with central pallor

17. Physiology and Pathophysiology Related to Anaemia

18. Oxygen Transport Oxygen is carried in blood in two forms: • Oxyhaemoglobin – 1 g fully oxygenated Hb carries 1.31 ml oxygen – 20 ml/100ml of arterial blood • Physical solution in plasma (dissolved) - 0.3 ml/100 ml of arterial blood at a PaO2 of 100 mmHg Oxygen content: Volume of oxygen carried in 100 ml of blood Arterial O2 content (CaO2)= (1.31 x Hb x SaO2) + (0.003 x PaO2)

19. Oxygen flux: Amount of oxygen leaving left ventricle per minute in arterial blood CO x arterial O2 sat x Hb conc. X 1.31 Oxygen delivery: Amount of oxygen that reaches systemic capillaries each minute DO2 =CO x CaO2 x 10 Compensatory mechanism in chronic anaemia • Increase in Cardiac Output

21. Oxygen consumption: Important determinant of adequacy of tissue oxygenation VO2=CO X (CaO2-CvO2) X 10 = 230-250 ml/min • Oxygen extraction ratio: Fraction of oxygen delivered to capillaries that is taken up into tissues . O2ER = VO2 / DO2 = 25% Compensatory mechanism in chronic anaemia • Increase in oxygen extraction ratio

22. Normal values of oxygen in arterial and Venous blood Normal range for oxygen transport parameters

23. . Compensatory mechanism Increase in 2-3 DPG leading to rightward shift of ODC Oxygen haemoglobin dissociation curve

25. Compensatory mechanisms • ↑ Cardiac output • ↑ Oxygenextractionratio • ↑ 2-3 DPG leading to shift of O2Hb dissociation curve to right • Decrease in blood viscosity → improved tissue blood flow • Release of erythropoietin → stimulates erythroid precursors in bone marrowto produce RBCs

26. Iron Deficiency Anaemia

27. Iron Deficiency Anaemia • Most common cause • Iron stored as S.ferritin & Hemosiderin. Adult male Adult female Stores 1000mg 300 – 500mg Losses 1mg/day 2mg/day • Daily iron requirement 2.5mg – early pregnancy. 5.5mg – from 20 to 22 wks 6 to 8mg – 32 wks onwards

28. Sources of iron lossmg lost Obligatory iron loss 180 ± 20 Increased red cell mass 400 ± 200 Foetal iron 270 ± 70 Placenta and cord 100 ± 70 Blood loss at delivery 150 ± 100 Total loss 1100 ± 460 TOTAL REQUIREMENT 800-900mg(4-6mg/d)

29. Haematological parameters Normal values 2nd half of Fe deficiency pregnancy anaemia Plasma iron (μg/dl) 60-120 65-75 <30 S.Ferritin (μg/l) 20-30 15 <12 TIBC (μg/dl) 300-350 300-400 >400 Transferrin saturation (%) 30 <16 <15 MCV (fl) 75-100 75-95 <75 MCH (pg) 27-32 26-31 <25 MCHC (%) 32-36 30-35 <30

30. How to investigate a case of Anaemia History • Asymptomatic • Fatigue, dyspnoea on exertion • Nausea, loss of appetite, constipation, indigestion • H/o bleeding (DUB, malena, haematuria) • Palpitation • H/o drug intake: salicylates, anticonvulsants chloramphenicol & cytotoxic drugs alcohol • H/o previous surgery in gut

31. Examination GPE - Pallor of skin & mucous membranes, glossitis, stomatitis, Koilonychia, mouth soreness, pedal edema, generalised anasarca, JVP ↑ Resp. system - Tachypnoea - Basal crepts CVS - Tachycardia, strong peripheral pulses with wide pulse pressure - Functional cardiac murmur (Ejection murmur) CNS - Mental disturbance, features of SACD

32. Investigations Complete haemogram including : Hb, Hct, RBC count, WBC count – TLC, DLC, Platelet count Peripheral smear - Cell size - Hb content - Anisocytosis, Poikilocytosis - Nuclear segmentation of neutrophils RBC indices – MCV,MCH,MCHC Reticulocyte count Iron supply studies – S.Iron, TIBC, S.Ferritin Urine analysis Stool examination for presence of ova, cyst

33. Other investigations Blood grouping Urea, creatinine S. bilirubin Thyroid hormones S. proteins Marrow examination – aspirate & biopsy ECG Hb electrophoresis

35. Management Prevention • Avoidance of frequent child birth. • Dietary prescription. • Adequate treatment for any infection. • Early detection of falling Hb level, levels should be estimated at 1st A/N visit, 30th & finally 36th week. • Supplementary Fe therapy (60mg elemental Iron three times a day). • National Anaemia Control Programme (NACP) : all pregnant women to be screened for anaemia. Non anaemic women would get iron (100mg) and folate (500ug) and those with anaemia should get 2 tablets daily.

36. Pregnancy <30wks Pregnancy 30-36wks Pregnancy >36wks IDA FA def. Parenteral Oral FA I/M iron I/V iron IDA FA def. Oral iron Oral FA Intolerance or Non-compliance I/M iron I/V iron Blood transfusion TREATMENT OF ANAEMIA IN PREGNANCY

37. Oral Iron Therapy Ferrous sulphate tablets 200mg (60mg elemental iron) X 3 times a day along with folate Hb rise : 0.7gm%/wk Drawbacks: - Intolerance - Unpredictable absorption rate - Non Compliant patient - Long time for improvement

38. Parenteral Iron Therapy Indications: - Failure to oral therapy - Non compliant patient - Case seen for 1st time during last 8-10 wks with severe anaemia Routes: IV, IM Hb rise : 0.7 – 1gm%/wk

39. IV Iron Therapy Iron Dextran 2ml ampoule containing 50 mg/ml elemental iron Total dose infusion (TDI) Deficit of iron calculated & total amount required to correct deficit is administered in 100ml saline in single setting I/V infusion slowly over several hours Dose = 0.3 X wt(100 – Hb%) or (deficiency in Hb X 250) + 50% =mg of iron Given @10 drops/min X 30 min. (diluted in normal saline or 5% dextrose) → no reaction → ↑ to 45 drops/min

40. Side effects: • Anaphylactoid reaction • Chest pain, rigors, chills, fall in BP, dyspnoea, haemolysis Treatment: • Stop infusion. • Give antihistaminics, corticosteroids & epinephrine Fe sucrose complex • Safe, effective, less side-effects • Low allergenic effect due to slow release of iron from the complex

41. IM Iron Therapy • Iron Sorbitol Citrate (Jactofer) • Iron Dextran (imferon) Oral iron should be suspended at least 24 hrs prior to therapy to avoid reaction. Drawbacks: - Painful injection (less with jactofer) - Chances of abscess formation & discolouration of skin over injection site

42. Blood Transfusion • Task force 1996, 2006 – No uniform transfusion trigger Decision to transfuse blood should be based on • Needs and risk of developing complications of inadequate oxygenation • Both clinical and haematological grounds Hb > 10gm/dl – transfusion rarely indicated.

43. BLOOD TRANSFUSION Patient factorsType of surgery Preg Preg Elective Emergency <36wks > 36wks C/S C/S -Hb ≤ 5gm% - Hb ≤ 6gm% - with H/o -assess without CHF without CHF APH,PPH, according -Hb 5-7gm%,if -Hb 6-8gm%,if previous to situation CHF, hypoxia, CHF,hypoxia, LSCS infections infections Hb 8 – 10 gm%, confirm BG & cross-matching Hb <8 gm%, 2 units to be kept ready in OT

44. Precautions during transfusion : Packed RBC to be preferred Addition of diuretics may be helpful If not urgent, blood should be transfused at least 48hrs before surgery for ; - restoration of intravascular fluid volume & blood viscosity - restoration of depleted 2,3 DPG content in stored blood

45. Blood Volume to be transfused: = normal blood volume x Hb% rise needed Hb% of transfused blood Normal Hb% of whole blood = 10 – 13gm% Hb% of packed cells = 18 – 23gm% Blood volume = 70 – 80ml/kg

46. Choice of Anaesthesia Depends on • Severity and type of anaemia • Extent of physiological compensation • Concomitant medical conditions • Type and nature of procedure • Anticipated blood loss

47. Anaesthetic Concerns Main anaesthetic concerns in chronic anaemia : • To minimize factors interfering with O2 delivery • Prevent any increase in O2 consumption • To optimize PO2 in arterial blood

48. Avoid hypoxia • Preoxygenation with 100% O2 • O2 supplementation in peri and postoperative period • Difficult airway cart • High FiO2, low conc. of volatile agents • Avoid and treat conditions that ↑O2 demand – fever, shivering, acute massive blood losses • N2O → cautious use in B12/folate deficiency

49. Minimize drug induced ↓ in CO Titrated doses of anaesthetic agents to prevent precipitous fall in CO Careful positioning, left uterine displacement Mild tachycardia and wide pulse pressure may be physiological

50. Avoid factors leading to left shift of ODC • Avoid hyperventilation → hypocapnia → respiratory alkalosis, ↓ CO • Avoid hypothermia - normal core body temperature, warm fluids Monitoring • Adequacy of perfusion and oxygenation of vital organs • Routine monitoring with temperature & urine output monitoring ± CVP, IBP, ABG analysis, serial Hb & HCT.