Sickle cell disease

  • All children with sickle cell disease are managed with the assistance of the Royal Children's Hospital Victoria.
    Sickle cell disease is caused by structurally abnormal haemoglobin (Hb S) that polymerises with shape change when deoxygenated, resulting in obstruction of blood flow.
    There are 3 common types causing sickle disease, all of which are treated the same way:

    • sickle cell anaemia (SS disease) is the most common
    • sickle ß Thalassemia
    • sickle haemoglobin C disease

    Acute crises may occur spontaneously, or may be precipitated by

    • Infection
    • Dehydration
    • Hypoxia
    • Sedatives, local anaesthetics and surgery

    All patients become functionally asplenic and thus at risk for infection particularly by encapsulated organisms (eg pneumococcus, meningococcus, haemophilus).

    Patients with sickle cell disease may present with the following problems  

    • Vaso-occlusive crisis 
    • Fever
    • Acute chest syndrome 
    • Acute splenic sequestration
    • Aplastic crisis
    • Stroke
    • Priapism

    Many of these presentations require urgent treatment, and discussion with the Haematology Consultant on-call is mandatory.

    General sickle crisis management 

    Assessment

    History
    • Symptoms and duration of pain, dyspnoea, fever, pallor and lethargy
    • Provoking factors (fever, travel, procedures, recent hospital admission)
    • Past history of chest crises and management  -  ICU admission/ ventilation
    • Bone pain (e.g. arm or leg pain) but maybe back or abdominal pain. (Most patients will be able to tell you this is pain similar to previous episodes.)
    • Comorbidities - asthma
    • Usual Treatment- chronic transfusion program or Hydroxyurea
    • Management at home
    Examination
    • Vital signs
    • Pallor or jaundice
    • Hydration
    • Signs of infection
    • Respiratory examination
    • Splenic examination – compare to patients baseline
    • Neurological examination (increased risk of stroke during aplastic crises/ anaemia)
    Investigations
    • FBE including reticulocyte count
    • Blood group & cross match
    • Blood and urine cultures if febrile
    • U&E's and LFT's if jaundice or dehydrated
    • Consider chest xray if febrile with respiratory symptoms
    • Obtain CT without contrast  to exclude bleed if concerns regarding stroke  or MRI if available without delay

    Management

    • Contact RCH on-call Haematologist
    • Start analgesics promptly – treat pain aggressively
      • See Suggested Analgesics below
    • Fluids
      • Push oral fluids
      • May require IV Fluids 
        • May require bolus 10-20 ml/kg 0.9% Saline
        • Maintenance rate (Plasma-Lyte 148 and 5% Glucose OR 0.9% sodium chloride (normal saline) and 5% Glucose)
        • Avoid excess fluids after initial resuscitation to reduced risks of chest crisis
    • Do not delay commencement of IV fluids or analgesics for topical anaesthetic cream
    • May require blood transfusion – discuss with haematologist on call

    Suggested analgesics

    Mild pain
      • Paracetamol
      • Ibuprofen
    Moderate to severe pain
      • Morphine 0.05 mg/kg/dose – IV   (repeat as necessary) – see Acute pain management
      • Some patients may benefit from continuous infusion via PCA (Patient Controlled Analgesia)

    Vaso-occlusive Crisis (Pain crisis)

    All episodes of pain should be treated initially as vaso-occlusive disease
    NB Chest pain may indicate an acute chest syndrome rather than as a vaso-occlusive episode if associated with respiratory symptoms.

    Specific Management

    See General Management section above

    Acute chest syndrome

    Background

    Sickle cell disease can produce an acute illness related to infarction of the lung tissue. Usually associated with lower respiratory symptoms, hypoxaemia and a new infiltrate on CXR. Chest pain and hypoxaemia may be the only signs.
    Chest pain should be treated as an acute chest syndrome and not simply as a vaso-occlusive crisis.
    NB This is a life threatening illness and patients may deteriorate quickly

    Specific management

    See General Management section above

    • Consider chest xray – but this should not delay commencement of treatment
    • Commence IV antibiotics – 3rd generation cephalosporin and coverage for atypical organisms (Roxithromycin or Azithromycin)
    • Oxygen to keep O2 sats >96% or for comfort
    • Early referral to PICU for respiratory support if significant hypoxia or respiratory distress

    Fever & sickle cell disease

    Background

    Patients are functionally asplenic and thus at greater risk for invasive disease particularly by encapsulated organisms.
    NB If pain is also present, then treat as Vaso-occlusive crisis concurrently

    If cough or dyspnoea is also present look and treat for acute chest syndrome concurrently

    Specific management

    See General Management section above
    • Commence IV antibiotics – 3rd generation cephalosporin and consider coverage for atypical organisms (Roxithromycin or Azithromycin) if significant respiratory component
    • Obtain appropriate cultures- blood  and urine

    Acute splenic sequestration

    Background

    Splenic sequestion is defined as a haemoglobin drop of at least 20 gm/l below baseline level for that patient with an acutely enlarged spleen. Mild to moderate thrombocytopenia is often present. Reticulocyte count is equal to or greater than patient's usual baseline.  Consider co-existent aplastic anaemia if reticulocyte count is low.

    Specific management

    See General Management section above

    • While waiting for blood give 0.9% sodium chloride (normal saline) (10-20 ml/kg) to treat hypovolaemia
    • Suggest initial transfusion to aim for Hb of 5-6 g/dL initially to ameliorate shock/haemodynamic instability  (not >3 g/dL )
    • Do not raise haemoglobin excessively / too quickly as the spleen will shrink and autotransfusion will occur. This will then increase the haemoglobin excessively with  increased risk of stroke due to hyperviscosity
    • Commence IV antibiotics if febrile – 3rd generation cephalosporin

    Aplastic Crisis & Sickle Cell Disease

    Background

    Aplastic crisis is defined as an acute illness associated with haemoglobin below baseline for that patient associated with a substantially decreased reticulocyte count (usually <1%). Usually associated with acute infection including parvovirus.
    May be associated with enlarged spleen as well (see Acute splenic sequestration)

    Specific Management

    See General Management section above
    • Intravenous fluids and oral intake to a total of maintenance
    • Transfuse red blood cells if patient is symptomatic with anaemia or Hb <5 gm/dL (do not increase Hb by >3 g/dL
    • Commence IV antibiotics if febrile – 3rd generation cephalosporin

    Stroke & sickle cell disease

    Background

    Acute neurological events occur in about 10% of patients with Hb SS.
    Can occur suddenly or as a complication of acute chest syndrome or aplastic crisis

     
    Specific management

     See General Management section above

    • Neuroimaging will be required to determine if haemorrhagic or ischaemic stroke
    • MRI is the modality of choice
      • Or if not available CT (NO CONTRAST as risk of hyperviscosity will worsen neurological state)
    • Transfusion support will be required, options include initial simple transfusion to Hb 10 g/dL followed by Red Cell Exchange (performed in ICU in acute setting)

    Priapism & sickle cell disease

    Background

    Priapism is prolonged painful erection of the penis often starting in the early hours of the morning.
    Most common in adolescent years.
    Occurs in 2 forms

    • stuttering episodes which last 2-4 hrs but are often recurrent and may precede a severe episode
    • severe attack lasting longer than 4 hrs and can result in impotence.

    Specific assessment

    History
    • Length of current episode
    • Associated symptoms - fever, dysuria, dehydration or pain at other locations
    • History of prior episodes and the previous treatments and effectiveness

    Specific management

    See General Management section above
    • Encourage emptying of the bladder: catheterise if unable to empty bladder
    • Simple measures – moderate exercise, take a bath or shower
    • Do not use ICE
    • Hydration, oxygen, analgesia and alkanization of the urine should be commenced as soon as possible
    • Priapism lasting more than 4 hours can result in ischaemia and is a urological emergency. Consult General Surgery (Urology) and on-call Haematologist.
    • Transfusion support may also be required to reduced risks of surgery, discuss with Haematology.