Dr Claire Strauss & Dr Andrea Leigh

This is the second of 2 articles regarding acute complications of sickle cell disease see Acute Complications of Sickle Cell Disease – Part 1

Acute Chest Syndrome 

Chest crises are covered in more detail in a separate article ‘Feeling Sickle in the Chest’ . 

They are essential to recognise as a leading cause of mortality in people with SCD. It is an acute clinical respiratory disease with changes on x-ray in someone with a sickling illness. It may present with classical respiratory difficulties such as shortness of breath or cough but also with chest, shoulder or abdominal pain. Like other pathologies in sickle cell disease it is fundamentally a condition of vaso-occlusion of microvasculature. There may not be an obvious cause, although infection is common. 

Management is firstly symptomatic i.e. oxygen and respiratory support as required (NB. Oxygen should only be used if saturations are <95%, in which case they should be checked hourly). As with most sickle cell crises ensure hydration along with analgesia to maximise chest movement and prevent atelectasis. Be sure to treat for possible infection and prepare for a likely transfusion or even an exchange transfusion. And don’t forget to watch out for progression to Acute Chest Syndrome in a patient with sickle cell disease who has presented with something different but worsened during admission.

Any vaso-occlusive pain episode can increase the risk of a chest crisis, particularly if they are reducing mobility and deep breathing. Day 2-3 of admission is a particularly risky time. 

Cerebrovascular Events

Children with SCD should have regular transcranial doppler measurement to establish their risk of stroke. If it is high they may enter a regular transfusion programme. Cerebrovascular events occur most commonly in young children and screening is recommended from age 2 years. They are more frequently infarctive and most common in the Middle Cerebral Artery territory but can occur in other watershed areas and can have an extremely varied presentation:

  • Focal weakness
  • Motor disruption eg limp
  • Speech abnormality eg slurring
  • Visual disturbance
  • Abnormal behaviour
  • Reduced GCS

Any New Neurological symptom or changes in neurology in a child with SCD is an intracerebral event until proven otherwise

If a TIA or Stroke is clinically suspected it is, of course, a clinical emergency requiring ‘ABC’ assessment and management and senior, expert input. Any neurological abnormalities require urgent investigation (non-contrast MRI or CT brain) and in the event of abnormality is an indication for an emergency exchange transfusion (if delayed or there is concomitant anaemia consider a top-up transfusion). Consult specialist haemoglobinopathy and neurology teams and consider whether transfer to a specialist heamoglobinopathy centre or paediatric intensive care unit is required.

Post-stroke management will include occupational therapy, physical rehabilitation, psychological support and prevention of further events with transfusion programmes or Bone Marrow Transplant. Thankfully, stroke incidence has reduced since screening with TCDs became a standard of care.

For further information see: RCPCH guideline: Stroke in Childhood, 2017.

Abdominal disease:

Abdominal crisis or syndrome is characterised by abdominal distension and tenderness but no rebound tenderness or rigidity. There is not usually significant vomiting and diarrhoea.

Girdle (or mesenteric) syndrome is characterised by an ileus, with vomiting, abdominal distension, absent bowel sounds and distended bowel loops with fluid levels on abdominal x-ray. 

Treat aggressively with ‘drip and suck’, antibiotic cover, incentive spirometry and surgical review. Exchange transfusion is usually curative and surgery usually unnecessary.

Don’t forget the common differentials of an acute abdomen. These may be complicated by sickling. Children with sickle cell disease can develop gallstones and associated conditions such as cholecystitis or pancreatitis. Acute chest syndrome may also present as abdominal pain due to lung base disease.

Gastrointestinal tract infections with Salmonella or Yersinia may be extremely serious and should be considered if there is diarrhoea, vomiting or abdominal pain associated with sepsis. These may particularly be present in children and young people on iron chelation therapy. Broad spectrum antibiotics should be started promptly.

Splenic or Hepatic Sequestration

Splenic Sequestration is most common under 5 years although it can happen at a later age. It can happen rapidly and cause severe anaemia and circulatory shock. The child may develop significant abdominal pain with evolving splenomegaly. There is likely to be a sudden fall in haemoglobin with a reticulocytosis.

Management requires addressing circulatory shock, although be aware that fluid resuscitation may further dilute a low haemoglobin. Top up transfusion is likely to be needed. A large volume of blood should be cross-matched and senior or specialist support requested. Be sure to treat any associated sepsis. Unfortunately splenic sequestration crises can recur and a splenectomy may ultimately be required.

Hepatic sequestration should be managed similarly. It can overlap with hepatic congestion by sickled cells due to another sickle crisis. There may be tenderness over the liver and there is likely to be a transaminitis and rise in bilirubin. As with splenic sequestration there is a risk of circulatory collapse. Consider covering for possible biliary sepsis.


This is the inflammation of digits causing pain and swelling because of sickling in the bones of the hands and feet. It most commonly occurs in young children with sickle cell disease, sometimes as the first clinical feature of the condition. It is self-limiting but the duration is varied. There is not generally any long term harm but shortening of digits is possible as the epiphyseal plates fuse prematurely.


This is a sustained, painful, penile erection which is not associated with sexual arousal and may last several hours. It occurs when blood is unable to leave the penis due to vascular occlusion by sickled cells, effectively causing a compartment syndrome. The condition can be ‘stuttering’ which means that the erection is transient but recurrent with small intervals. Priapism is most common from puberty into a person’s 40s but can be seen in younger boys.

It may occur in association with normal morning erections which usually pass upon bladder emptying. Other triggers are the same as any sickle cell crisis. It may occur during sex due to the physical strain of intercourse.

Priapism can result in necrotic tissue damage and fibrotic scarring which can ultimately affect erectile function. Erectile dysfunction is more likely if priapism is not treated quickly, particularly after 4 hours (fulminant priapism). Remember that a patient may find this situation embarrassing and be reluctant to seek help.

Prevention strategies include emptying the bladder at night and immediately on waking to avoid early morning erections and avoidance of alcohol, cannabis, tobacco and sildenafil. 

In hospital, duplex ultrasonography may confirm ischaemic priapism although imaging should not delay intervention. 

Treatment, as for any sickle cell crisis, should be initiated by ensuring analgesia, hydration and adequate oxygenation. Blood transfusions or exchange transfusions may also be used.

Medical management includes oral sympathomimetic medication (adrenergic agents, hormonal analogues or smooth muscle regulators) . Invasive measures include corporal blood aspiration,irrigation +/- intracavernous administration of a sympathomimetic agent e.g.  phenylephrine but if initial interventions are unsuccessful surgery may be necessary to shunt blood away from the corpus cavernosum. 

Acute Renal Disease

Microvascular occlusion in the kidneys results in medullary hypoxia, microinfarctions and papillary necrosis causing a variety of glomerulopathies. As with anyone, dehydration and sepsis may initiate acute renal failure however there is increased risk for people with SCD as they have an inability to concentrate urine. Beware that they may have a low baseline creatinine so a ‘normal’ level may actually indicate a rise from baseline.

Take home message:

Acute complications of sickle cell disease are varied but essential to recognise and manage promptly due to a risk of rapid deterioration. 

Basic management includes:

  •  analgesia as necessary
  • ensuring adequate hydration
  •  and ensuring adequate oxygenation. 
  • Blood transfusions are also frequently required 
  • important to consider early antibiotics with signs of infection. 

Don’t forget to seek specialist advice if you are concerned about a child with sickle cell.

General References

Dick, MC and Rees DC (2019) Sickle Cell Disease in Childhood: Standards and Recommendations in Clinical Care https://www.sicklecellsociety.org/wp-content/uploads/2019/11/SCD-in-Childhood_Final-version-1.pdf

David Rees, Thomas N Williams and Mark T Gladwin (2010). Sickle-cell disease. The Lancet 376 (9757) pp. 2018-2031

University College London Hospital clinical guidelines

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