Definition
A.Vaso-occlusive crisis (VOC) involving the bones is the most consistent and characteristic feature of sickle cell disease (SCD).
B.VOCs and their accompanying pain present most frequently in the extremities, chest, and back, although multiple sites may be involved.
Incidence
A.Approximately 5% of the world’s population carries an abnormal hemoglobin gene, with SCD being the most predominant form.
B.The greatest burden of the disease lies in sub-Saharan Africa. SCD affects nearly 100,000 individuals in the United States, the majority of whom are African American.
Pathogenesis
A.SCD occurs as a result of change in the amino acids of the beta globin chain of the hemoglobin molecule. Under circumstances where deoxygenation occurs, causing a reaction leading to sickling
of the red blood cell, reoxygenation allows the cell to return to its normal shape; however, repeated sickling damages the cells, leaving them permanently sickled.
B.Chronic hemolysis and high viscosity and vascular occlusion are the two main pathologic processes leading to the symptom most often associated with SCD. Infarction occurs as a result of stasis of the rigid sickle cells in the vascular beds of organs as a result of decreased blood flow. Sickled cells lose their flexibility and are unable to pass through the capillaries. Additionally, sickle cells tend to exhibit more adhesiveness to vascular endothelium and other blood cells, contributing to the obstruction of blood flow.
C.Bone pain crisis is one of the most common manifestations of SCD. Pain occurs as a result of activating afferent nerves in bones experiencing ischemia. Long bones including the femur and humerus, as well as ribs, vertebrae, pelvis, and sternum, are common sites of pain, often with multiple sites affected at once. Painful crises may vary in intensity.
D.When arising in other sites, pain can be confused with, or can be an early indication of, another acute complication such as stroke, liver or splenic sequestration, or constipation associated with opioid use. The etiology of the pain must be identified in order to rule out potential causes of pain other than an uncomplicated VOC, such as cardiac ischemia, pneumonia, or other abdominal complications. VOC can occur in the presence of other complications, making diagnosis more challenging. No diagnostic test is able to rule in or to rule out a VOC. Diagnostic tests are most useful in ruling out other causes of pain.
E.Acute abdominal pain may result from vaso-occlusion of mesenteric vasculature, sequestration of blood in the spleen, biliary tract disease, or non-SCD related conditions. Sequestration most often occurs in the spleen, but the liver and lymph nodes may also be sites of sequestration. If not recognized and treated rapidly, acute sequestration may result in shock and death. Mesenteric syndrome is a rare complication. The patient may present with generalized abdominal pain, localized or rebound tenderness, and rigidity. Paralytic ileus with vomiting, distention, and absence of bowel sounds along with dilated bowel loops, and air-fluid levels on abdominal x-ray are hallmarks.
Predisposing Factors
A.Exposure to cold.
B.Dehydration.
C.Infection.
D.Physical exertion.
E.Tobacco smoke.
F.Alcohol use.
G.Drug abuse.
H.High altitude.
I.Hypoxic conditions.
J.Physical pain.
K.Pregnancy.
L.Hot weather.
M.Emotional stress.
N.Onset of menses.
Subjective Data
A.Common complaints/symptoms.
1.Extremity pain.
2.Chest pain.
3.Back pain.
B.Common/typical scenario.
1.Other signs and symptoms.
a.Abdominal pain.
b.Tachycardia.
c.Tachypnea.
d.Fever.
e.Pallor.
f.Jaundice.
C.Family and social history.
1.Recent history of precipitating factors.
2.Previous VOC.
3.Comorbid conditions.
4.Current treatment regimen, including analgesics and other medications, as well as transfusions.
D.Review of systems.
1.Ask about pain and where it is located.
a.Pain can affect any part of the body.
2.Ask about any infections, cough, or fever.
3.Cardiac.
a.Chest pain.
b.Palpitations.
4.Neurology.
a.Any weakness or shaking.
Physical Examination
A.Vital signs.
B.Oxygen saturation.
C.Skin and mucous membranes, noting pallor or jaundice.
D.Hydration status.
E.Cardiac examination.
F.Lung examination.
G.Abdominal examination.
H.Neurological examination.
Diagnostic Tests
A.Complete blood count (CBC).
B.Blood and urine cultures if febrile.
C.Chest x-ray if pulmonary symptoms.
D.EKG to rule out ischemia.
E.Chemistry panel.
F.Liver function testing.
G.Urinalysis.
Differential Diagnosis
A.Avascular necrosis.
B.Acute chest syndrome.
C.Gout.
D.Bone infarction.
E.Osteomyelitis.
F.Joint infection.
G.Cerebrovascular accident.
H.Pneumonia.
I.Asthma.
Evaluation and Management Plan
A.General plan.
1.Treatment of bone pain crisis includes providing adequate analgesia, hydration, prophylactic or therapeutic antibiotics after collection of appropriate cultures, and oxygenation when hypoxia is evident.
2.Oral hydration may be inadequate, making intravenous hydration necessary.
3.Pain management is best directed by the patient’s report of pain.
a.Analgesia should be offered within 30 minutes of presentation with an acute painful event.
b.Before prescribing analgesics for an acute painful sickle cell episode, the provider should inquire about and consider any analgesia taken by the patient for this painful episode prior to his or her arrival at the hospital.
i.The effectiveness of pain relief should be assessed frequently. If the patient with severe pain has not had relief, a second dose of strong opioid should be offered. Patient-controlled analgesia should be considered if repeated boluses of strong opioid medications are needed within a 2-hour period.
ii.Frequent monitoring for adverse events associated with strong opioids, including respiratory depression and excessive sedation, is advised.
iii.An alternative diagnosis should be considered if the patient does not respond to standard treatment for an acute crisis.
iv.Consideration of exchange blood transfusion should be given in situations where pain is unrelieved with conventional measures.
v.Nonpharmacologic measures include:
1)Physical therapy.
2)Relaxation.
3)Distraction techniques.
4)Music therapy.
5)Meditation, which may be beneficial.
6)Prophylactic incentive spirometry, which is recommended to reduce the risk for acute chest syndrome.
B.Patient/family teaching points.
1.Preventing sickle cell crises is the keystone management approach.
2.Patients need to be taught how to recognize their own triggers and to have a self-assessment and treatment plan at home.
3.Prevention of infection is also important.
a.Reinforcing proper hygiene is key.
b.Reinforcing universal precautions is essential.
4.Remind patients that the use of live vaccines is contraindicated in sickle cell due to the immunosuppressive therapy they receive.
C.Pharmacotherapy.
1.A dose of a strong opioid should be offered to all patients with severe pain (7 or greater on a 0–10 scale) and those with moderate pain (4–7 on a 0–10 scale) who have already received some analgesia before their arrival at the hospital.
2.Severe VOC requires parenteral opioid analgesia and hydration in a hospital setting.
3.The dose of the analgesia should be titrated with the severity of the pain until adequate control is achieved with a scheduled dose regimen, with short-acting agents for breakthrough pain.
4.Meperidine should be avoided because of neurotoxicity associated with high doses.
5.A weak opioid may be considered for those with moderate pain who have not yet received some form of analgesic. Except when contraindicated, acetaminophen, or nonsteroidal anti-inflammatory drugs (NSAIDs), should be offered to all patients via a suitable route in addition to opioids.
6.All patients receiving opioids should receive laxatives on a regular basis as well as antiemetics and antipyretics as needed.
D.Discharge instructions (If standard accepted guidelines exist please use discharge template).
1.Long-term follow-up is essential.
2.Teach patients to recognize signs of infection and what to do when the signs manifest.