This is about emergency approach to a patient presenting with acute severe hemolysis. It mainly describes general approach and how to choose investigations appropriately. In depth discussion about the management of autoimmune haemolytic anaemia with warm antibody, cold antibody, all-immune antibody, drug induced, microangiopathic syndromes- TTP, HUS, DIC, Macrovascular hemolysis, sickle cell disease, thalassemia, G6PD deficiency, Hereditary spherocytosis and paroxysmal nocturnal hemoglobinuria is included.

1. ED APPROACH TO
ACUTE
HEMOLYSIS
Dr KTD Priyadarshani
Registrar in Emergency Medicine
National Hospital- Kandy
2023/09/07

2. Hemolytic anemia
Definition

3. Classification

4. Approach

8. Confirm homolysis
1. Increased
absolute reticulocyte count
LDH (elevation is more pronounced in intravascular haemolysis)- strikingly elevated in
microangiopathic homolysis
Total & Indirect Bilirubin (i.e. unconjugated). Total up to 4 mg/dL ( 68 µmol/L) or more.
Bilirubin higher than this may indicate some degree of hepatic dysfunction.
Plasma free haemoglobin (PFHb)
2. Decreased
Haptoglobin (intravascular haemolysis)- A normal plasma protein that binds & clears free
Hb released in to plasma, is decreased in HA. However, the haptoglobin level is influenced
by many factors and in not always a reliable indicator of homolysis, particularly in liver
disease.
3. Urine
Haemoglobin- when capacity of renal tubular cells to reabsorb Hb exceeds.
Haemosiderin (useful in the diagnosis of prior intravascular haemolysis)- hemosiderin in
shred renal tubular cells

14. Resuscitation
Symptomatic management

15. ACQUIRED PATHOLOGIES
■ Immune mediated
– Warm antibodies
– Cold antibodies
– Mixed antibodies
– Alloimmune
■ Drug induced
■ Microangiopathic syndromes
– TTP
– HUS
– DIC
■ Macrovascular hemolysis

16. Immune mediated acquired
■ 3 main categories- autoimmune, alloimmune
& drug induced
■ Autoimmune- make Ab against their own
RBCs
■ Tested by direct Coombs test

17. AIHA- Warm antibody
■ Hemolysis is predominantly extravascular
■ IgG Antibody coated RBCs consumed mostly by splenic macropghages & liver-
Kupffer cells
■ Partial phagocytosis by splenic macrophage→ spherocyte → trapped in the red
pulp of the spleen
– Spherocytosis found on peripheral smear correlates positively with severity
of extravascular hemolysis
■ When large amount of IgG are present in RBC, complement may be fixed. Direct
complement lysis of cells is rare, but presence of C3b on surface of RBC allows
Kupffer cells to participate in hemolysis

18. ■ Cause
– Idiopathic
– SLE
– Other rheumatic disorders
– CLL
– Lymphomas
■ Clinical features
– Typically produce rapid onset life threatening
anemia
– Symptomatic anemia with Heart failure
– Jaundice & heart failure
■ Investigations
– FBC- severe anemia, HCT <10% ( Evans
syndrome- 10% of patients coincident immune
thrombocytopenia)
– Reticulocytosis
– Blood picture- spherocytes
– Coombs test-positive

19. Management
■ Severe hemolysis- therapeutic plasma exchamge a a transient stabilizing measure
■ Blood transfusion- transfuse allogenic RBCs without producing potentially harmful transfusion
reaction
– Assess for alloantibodies and autoantibodies
– Hematology and transfusion medicine consultation
– Time consuming assessment- for emergency transfuse least incompatible units slowly and
in smallest amounts necessary with close monitoring
■ High dose corticosteroides- oral prednisolone 1-2 mg/kg/day in divided doses for 3-4 weeks
followed by lower doses for 3-4 months
– Improvement is expected in 80% to 85% of patients( both DAT positive or negative), but
complete remission occurs in only approximately 30% of patients
■ Monoclonal antibodies ( e.g rituximab) or immunosupressive agents ( e.g azathioprine,
mycophenolate mofetil, cyclosporine, cyclophosphamide) are used to decrease autoantibody
production
■ Splenectomy- removes main site of extravascular hemolysis in IgG mediated disease and a
major site of general autoantibody production,
– clinical benefit in up to 60% of patients and potential for long term remission or a complete
cure.
– Serious complication of splenectomy- overwhelming post splenectomy infection due to
encapsulated bacteria

20. AIHA- Cold antibody
■ Due to IgM autoantibody usually directed against the I/i antigen on RBC
■ At cooler parts of circulation ( fingers, nose, ears) IgM attach to RBC and trigger
complement fixation on the RBC surface. Complement lysis of the RBC by membrane
attach complex rarely occurs.
■ When the RBC return to warmer temperature, the IgM antibody dissociates, leaving
complemet on the cell. C3b recognosed by Kupffer cells & RBC sequestred and destructed
in Liver.
■ 2 major disorders
– Cold agglutinin disease
– Paroxysmal cold hemoglobinuria
■ 50% secondary cold antibody cases are associated with lymphoproliferative disorders, with
underlying infection as the next uderlying casue

21. Cold agglutinin disease
■ Cause
– Idiopathic
– Waldernstrom macroglobulinemia
– Lymphoma
– CLL
– Acute post infectious cold agglutinin disease
■ Mycoplasma pneumona, E coli. Listeria monocytogens, treponem apallidum.
■ Viral infection – IMN, Measels. Mumps, CMV, influenza, VZV, HIV
■ Clinical features
– Mild anemia with reticulocytosis & rarely spherocytosis
– Hemolysis 2-3 wks after the onset of illnes & resolves in 2-3 weeks
■ Investigations
– Blood smear- at body temp- no agglutination/ at room temp- agglutinated RBC)
– Direct Coombs test- positive
– Serum cold agglutinin titer- semiquantitative
– Serum protein electrophoresis- Monoclonal IgM

22. Management
■ Symptomatic management
– Keep patient warm
■ Steroides
– Usually ineffective except when associated with lymphoproliferative disorder
– Considered in children with severe hemolytic anemia
– But benefit is uncertain because the infection related disease is self limited.
■ Splenectomy is not helpful
■ Plasmaparesis as a temporising measure in lfe threatening cases
■ If RBC transfusion is necessary, transfused blood should be infused at 37C using a blood
warmer. Transfusions should be limited as they may worsen ongoing hemolysis because
most cold antibodies act against the I/i group antigens found on most donor RBCs. Donor
complement in the transfused product also may exacerbate ongoing hemolysis
■ Relapses can be treatet with high dose imminoglobulin, rituximab or cytotoxic agents
such as cyclophosphamide, fludarabine or immunosupressive agents such as
cyclosporin.

23. Paroxysmal cold hemoglobinuria
■ Caused by biphasic hemolysin immunoglobulin G autoantibody ( Donath-Landsteiner DL
Antibody)
– Antibody binds to RBCs and fixes early complement components adhere and produce
intravascular lysis of RBCs at warmer, physiologic temperatures
■ Bursts of cold weather- induced intravascular hemolysis leads to bouts of dark urine or
hemoglobinuria or high fever, chills, headache, abdominal cramps, nausea & vomiting, diarrhea &
leg & back pain.
■ Acute renal failure may revelop as a complication
■ Causes
– Primary- rare
– Secondary
■ In children
■ After a preceding infection with adenovirus, influenza A, measels, mumps, EBV, CMV, Varicella, M
Pneumoniae, H Influenzae or E Coli
■ Managemnt
– Keep warm
– Steroids can be considered in children with severe HA
– Infection related disease is self limited
– Secondary to syphilis- responds to effective antibiotic treatment
– Splenectomy is not helpful, Plasmaparesis as a temporising measure in lfe threatening
cases

24. Mixed antibody AIHA
■ Both warm and cold autoantibodies to RBC
■ Present as either primary or secondary disease
■ Cold- associated with lymphoproliferative and autoimmune diseases, particularly
SLE
■ The course of illness is usually chronic with severe exacerbations
■ Usually steroid responsive
■ Can be treated with splenctomy and responds ot immmunosupressive therapy

25. Alloinmmune HA
■ Exposure to allogenic RBCs with subsequent alloantibody formation
■ Common cause- hemolytic disease of newborn
– RhD negative maternal immune system develops igG alloantibodies upon exposure to
RhD positive fetal RBcs
– Maternal alloantibodies then cross the placentamledaing to fetal RBC destrusction
– Anemia range from mild to potentially fatal - IUD “hydrops fetalis”
■ Managemnt
– Administration of anti-D immunoglobulin following fetomaternal hemorrhage event and
soon after delivery
– Established hemolytic disease of newborn- intrauterine and intravscular fetal
transfusion, plasma exchange or IV immunoglobulin therapy
■ Adult- have a history of RBC transfusion which sensitizes patient to allogenic RBC antigens.
A subsequent transfusion can rsult in immediate alloantibody production result in hemolytic
transfusion reaction.

26. Drug induced HA
■ Rare 1in 1000,000 patients
■ Drug coats RBC membrane & autoantibody is directed
against the membrane- drug complex
■ Result either positive or negative direct test and can be
difficult to distinguish from autoimmune hemolytic anemia
■ Review of current medications. & stop offending agents
■ Symptomatic treatment
■ Transfuse carefully screened RBCs
■ Steroides in cases of severe HA

27. Microangiopathic syndromes
■ 2 classic syndromes- TTP and HUS
– Platelet aggregation in the mocrovascular circulation via mediation of von
Willebrand factor.
– MAHA or Schistocyte forming hemolysis occurs fom fragmentation of RBCs
during travel through these partially occluded arterioles and capillaries
■ Causes
– TTP-HUS
– DIC
– Malignant disease
– Vasculitis
– Malignant hypertension
– Preeclampsia/HELLP
– Homograft rejection

28. Thrombotic thrombocytopenic
purpura
■ Classic pentad
– CNS abnormalities
– Renal pathology
– Fever
– Microangiopathic hemolytic anemia
– Thrombocytopenia
■ Untreated TTP carries a high mortality rate, but plasma exchange therapy can achieve
remission of disease in >80% of patients
■ Pathophysiology- deficiency in activity of ADAMTS-13 which is needed to cleave vWF.
TTP is associated with ADAMTS-13 activity at levels <10% of normal

29. ■ Causes-
– Pregnancy
– HIV
– Influenza vaccine
– Acute pancreatitis
– Drugs- ciprofloxacin, ofloxacin, levofloxacin, quinine, sirolimus, risperidone,
clopidogreal, lansoprazole, valcyclovir, mitimycin, infliximab, ticlopidine
Clinical features
■ Platelet aggregation- thrombocytopenia
■ Microangiopathic hemolytic anemia
■ End organ damge
– CNS- sizure, stroke, focal neurological deficits, coma
– Renal- AKI

30. Investigations
■ Normal coagulation studies- distinguish from DIC
Management
■ Plamsa exchange therapy
– Very effective- Goal to achieve a normal platelt count
– Daily plasmapharesis of 40 ml/kg or up yo 1-1.5 times a patient’s plasma volume is
performed and then either weaned in frequency or stopped once normal platelet
count is reahed for 2-3 consecutive days
■ FFP
– If plasmapheresis cannot be performed immediately
■ Infusion with factor VIII concentrate containing ADAMA-13 activity can be considered
for patients with plasma allergy after specialist consultation and review

31. ■ Severe TTP
– RBC transfusion
– Anticonvulsants
– Antihypertensives
– Hemodialysis
■ Avoid platelet transfusion except in lifethreatening bleeding or ICH because acutely
worsend thrombosis can lead to renal failure.
■ Aspirin- can exacerbate hemorrhgic complications in severe hthrombocytopenia. Heparin
is not benefiical in TTP.
■ Corticosteroides, rituximab and cyclosporine may be used in the treatment of
autoimmune TTP
■ Discontinue the inciting drug in all cases of drug associated TTP
■ Relapse – new cae onset >30 days after completion of remission. In 20%– 50% of cases
– Triggers are same as inciting original cases.

32. Hemolytic uremic syndrome
■ Consists of microangiopathic hemolytic anemia, acute nephropathy or renal failure and
thrombocytopenia
■ Classified as typical & atypical with prognosis favoring typical cases
Typical HUS Atypical HUS
(>90% of cases) occurs in children
between 1-4 years
Presenting in 1 weeks in to
infectious diarrhea that is often
bloody and without fever
Causative organism- Shiga toxin
producing E coli, with serotype
O157:H7
5-10% of cases
In older children and adults
Causative organism-
Streptococcus pneumoniae, EBV
or noninfectious causes such as
BM transplntation or administrstion
of immunosupressant or
chemotherapeutic agents

33. ■ Pathophysiology
– E coli O157:H7- possesses potent virulence factors that allow invasion of
intestinal epithelial cells & subsequent transmural migration
– The colonic inflammation produces hemorrhagic colitis
– Shigs toxin is absorbed into systemic circulation, binds with greatest
affinity to receptors found on the surface of glomerular & renaltubular
epithelial cells & to a lesser extent to receptors lining cerebral, colonic &
pancres epithelial cells
– Molecular mimcry may exist between human CD36 which is found on
endothelial cells & platelets.
– Toxin mediated microvascular injury promotes platelet aggregation,
thrombus formatin at the injury site, and shearing of RBCs.
Clinical features
■ Typically present 2-14 days after diarrhea develops – so may present with
diarrhea illness phase or often without fever
■ ARF 55-70%in typical HUS & 80% recover but atypical HUS permanent renal
failure Or neurological damge
■ Mortality 5-15% in typical 25% in atypical

34. Investigations
■ No bloody diarrhea
– stool for fecal leukocytes- occult inflammatory colitis
– Stool culture- for E Coli O157:H7
■ Blood diarrhea +
– Stool tesing for for Shiga toxin producing bacteria
■ Other Ix
– SE, RFT- detect nephropathy
– Urinalysis- RBC, RBC casts, protein
Management
■ Hydration
■ RBC transfusion for significant anaemia
■ Haemodialysis if ARF
■ Do not use antimotility drugs for E Coli O157:H7 – increase risk of developing HUS,
Antibiotics use is controversial- increase toxin expression from bacteria & risk of HUS
■ Atypical HUS is treated with eculizumab- aggressive treatment significantly reduces
incidence of permanent renal failure and lower the death rate.

35. Macrovascular hemolysis
■ Occur in Prosthetic heart valve, intracardiac patch repair, aortofemoral bypass, coarctation of
aorta, severe aortic valve disease,or ventricular assisst device or extracorporeal circulation-
during CP bypass, plasma exchange or hemodialysis
■ Prosthetic heart valves-
– Mechanical valves- turbulent blood flow with high shear stress across the valve
– Current models- due to perivalvular leak
■ Hemodialysis
– Mechanical shear stress
– Chemical contaminant
– Exposure to dialysis membrane
■ Management
– Mild- supplement iron & folate to promote healthy reticulocytosis
– Beta blocker in prosthetic heart valve- reduce HR & RBC shear stress
– Pentoxifylline- reduce blood viscosity & improves RBC flexibility & deformability

36. Disseminated Intravascular Coagulation
(DIC)
■ Syndrome caused by systemic inflammation due to another undelying disease.
Causes
■ Sepsis
■ Trauma
■ Malignancy
■ Placental abruption
■ Severe liver disease
Pathophysiology- inflammatory cytokines that initiate the intrinsic (tissue factor) pathway of the
coagulation. Simultaneously, endogenous fibrinolytic or anticoagulant systems cannot be
maintained. This leads to excessive coagulation and consumption of platelets and clotting
factors, which can subsequently lead to excessive bleeding as well at thrombosis

37. Investigations
■ PT, APTT- prolonged
■ D-dimer- elevated
■ Fibrinogen- low
■ Blood picture- schistocytes and RBC fragments
Management
■ Recognition of the disorder
■ Proper resuscitation
– Platelets should be considered when the platelet count is < 50,000mm3 and/or significant bleeding
is present.
– RBCs should be provided if there is active bleeding present and or if the patient is hemodynamically
unstable
– Coagulation factor replacement with fresh frozen plasma (FFP) should also be given when active
bleeding exists
– If massive bleeding is present or fibrinogen is < 150, fibrinogen should be replaced via
cryoprecipitate
– Anti-fibrinolytic treatment, such as tranexamic acid is recommended only for the active or massive
bleeding
■ Treatment of the underlying disorder and when indicted
■ Treatment focused on reversing the coagulopathy

39. HEREDITARY PATHOLOGIES
■ Result fro defects in Hb production, abnormalities in RBC metabolism or
changes with in RBC membrane structure.
– Abnormal Hb structure
■ Sickle cell disease
– Disorders of abnormal Hb production
■ thalassemia

40. Sickle cell disease
■ Autosomal recessive disorder
– A single DNA base change leads to amino acid substitution of valine for glutamate
in the 6th position on the beta globin chain
■ Haemoglobin S is unstable and polymerises in the setting of various stressors, including
hypoxemia & acidosis leading to formation of sickled RBCs.
■ Initiating event may not be identifiable, but stressors such as infection, cold, dehydration
and altitude.

41. ■ Chronic hemolytic state due to shape of the RBC.
■ Baseline Hb is 6-9 g/dL, retic count 5-15%
■ Blood picture
– sickled cells 5-50% of RBC
– Hyposplenism
■ Howell-Jolly bodies
■ Target cells
■ With infection, hemolytic process may worsen & Hb
may drop from previous baseline
■ It is uncommon for the hemolysis to be so severe as to
require transfusion

42. Thalassemia
■ Defective synthesis of globin chains, resulting in an inability to produce a normal
adult Hb
■ Hallmark is- microcytic, hypochromic, hemolytic anemia
■ Categorised depending on the globin chain affected or the abnormal hemoglobin
produced.
– Alpha thalassemia
– Beta thalassemia

45. G-6-PD Deficiency
■ Most common enzymopthy of RBC in humans affecting >400 million people
worldwide
■ >400 variants
■ X linked inherited disorder- primarily affect males, females must have 2 defective
genes to be affected. But because expression of this gene is variable, women with
one abnormal gene may still show some symptoms
■ Most adults are usually asymptomatic- but may have intermittent hemolytic anemia
& few have chronic hemolysis
■ G6PD deficient RBC is susceptible to oxidative stress and precicpitated hemoglobin
is recognized by the presence of heinz bodies on the peripheral blood smear. The
affected RBC are removed from the circulation by the spleen- extravascular
hemolysis

46. ■ Diagnosis
– Established by the demosntration of
decreased enzyme activity through
quantitative assay. (Perform weeks after
hemolysis resolves)
– Blood film- evidence of oxidative
hemolysis
■ Bite cells
■ Blister cells
■ Heniz bodies- precipitated membrane Hb
aggregates
– Acute symptoms- FBC, reticulocyte count
( to evaluate level of anemia & BM
function). Hb rarely falls below 8 g/dL.
– serum bilirubn levels, serum
aminotrnasferases ( to exclude other
causes of jaundice)
– Urinalysis ( hemoglobinuria)
– Lactate dehydrogenase ( elevated in
hemolysis and a marker of hemolytic
severity)

47. Treatment
■ Determined by patient’s overall clinical condition & removal of offending
agent, if present.
■ If the illness is severe blood transfusion with RBCs
■ Fluids- prevent renal injury
■ Known G6PD – aggressive treatment for infections and avoid oxidative
drugs
■ Drugs with solid evidence to cuase acute hemolysis in patients with
G6PD- dapsone, phenazopyridine, nitrofurantoin, primaquine,
rasburicase, pegloticase, mehtulthioninum chloride ( methylene blue) and
tolotnium chloride ( toliuidine blue)
■ Even with continuous use of the offending medication, the hemolytic
episode is self limited because older RBC with low enzyme activity are
removed and replaced with a population of young RBC with adequate
functional levels of G6PD.

48. Hereditary Spherocytosis
■ Due to eryhthrocyte membrane defect
■ Inheritance autosomal dominant pattern + less common autosomal recessive variant exists
Clinicl features
■ Mild disease- 20% autosomal dominant inheritance
– Normal Hb, little or no splenomegaly, but susceptible to hemolytic or aplastic episodes triggered by
infection
■ Moderate disease- 75% autosomal dominant inheritance
– Mild to modearate anemia, modest splenomegaly, periodic episodes of hemolysis with jaundice and
and an increased incidence of pigmented gallstones.
■ Sevre- 5% autosomal recessive inheitance
– Significant hemolytic anemia requiring blood transfusion, chronic jaundice and an enlarged spleen.
■ Main complicatins- aplastic or megaloblastic crisies, hemolytic crises. Cholecystitis or cholelithiasis &
neonatal hemolysis with jaundice.
■ Neonatal jaundice during 1st week of life in 30-50%

49. ■ Diagnosis
– Peripheral blood smear- spherocytes with normal to
low MCV and increased MCHC >36%
– Diagnosis= clinical+ examination+ family history+
RBC indices & morphology
■ Treatment
– Severe anrmia- RBC transfusions, splenectomy

50. Paroxysmal nocturanal
hemoglobinuria
■ Rare acquired clonal hematopoetic stem cell disorder- result in abnormal sensitivity of the
red cell membrane to lysis by complement and therefore hemolyis.
■ Clinical features
– Episodic hemoglobinuria- reddish brown urine often noticed in the first morning urine
due to fall in blood pH while sleeping ( hypoventilation)
– Prone to thrombosis- mesenteric, hepatic, Sagital vein, skin vessels ( painful
nodeuls).
– May associate with AML, idiopathic aplastic anemia
■ Investigations
– Urine hemosiderin- episodic hemolysis
– Serum LDH- quite elevated
– Best screening- flow cytometry of RBC & WBC to demonstrate deficiency of CD55 &
CD 59

51. ■ Treatment
– Mild disease- not requiring intervention
– Severe disease
■ Associated myelodysplasia or previous aplastic anemia- allogenic
hematopoetic stem cell transplantation
■ Severe hemolysis- usually require BT or thrombosis or both- Eculizumab
– Humanised monoclonal antibody against complement protein C5 given
every 2 weeks
– Binding Eculizumab to C5 prevent clevage so membrane attack complex
cannot assesmble
– It improves quality of life & reduces hemolysis, transfusion requirements,
fatigue & thrombosis risk
■ Corticosteroides- decrease hemolysis

52. Take home message
A Rule of thumb!
Life in the fast lane- Hemolytic anemia

53. References
■ Tintinali 9th Edition
■ Life in the fast lane
■ https://www.emdocs.net/hemolytic-anemias-rare-important-diagnosis-
emergency-department/
■ Essential Hematology- 6th edition
■ CMDT- 2020