Fever in a child with sickle cell disease (SCD) is a medical emergency, because of the possibility of overwhelming Streptococcus pneumoniae sepsis. By age 1 year, 30% to 50% of infants with homozygous sickle cell anemia (HbSS) have diminished or absent spleen function, more than 90% by age 4 years. Though splenic hypofunction occurs less commonly and at a later age in children with hemoglobin SC (HbSC) and sickle β0-thalassemia, they should also be considered at risk. Although availability of conjugated pneumococcal vaccines (most recently Prevnar 13) has reduced the prevalence of invasive pneumococcal disease, prompt empiric therapy with an appropriate antibiotic remains critically important. To some extent, use of Prevnar 7 resulted in emergence of nonvaccine, penicillin-sensitive serotypes as causes of invasive disease, and children less than age 5 should be receiving prophylaxis with penicillin. Patients with pneumococcal bacteremia are often well-looking for a period of several hours prior to sudden circulatory collapse and death; the presence of otitis media or other localized infection does not exclude the possibility of bacteremia. Children with high fever (T >40°C) and/or headache may require lumbar puncture. Although children with acute chest syndrome (ACS) may present with obvious respiratory distress, presentation may be subtle, and careful clinical and radiographic assessment is required. Moreover, although parents are advised to bring children to the hospital because of risk of fulminant sepsis, the fever is often due to viral illness.
Figure 11.1 ▪ Sickle Cell Anemia.
Fever, pain and swelling with erythema can be seen in both osteomyelitis and vaso-occlusive crisis (VOC) usually due to bone marrow infarction; clinical differentiation between the two may be difficult. (A) Osteomyelitis of the humerus with erythema, swelling, and fever were seen in this child with SCD. (B) Swelling of the elbow and forearm with pain, fever and similar signs of inflammation were seen in a different child with VOC. (Photo contributor: Binita R. Shah, MD.)
Children presenting with fever should be urgently triaged and immediately seen by a physician. After brief examination, blood should be obtained for a complete blood count (CBC) with a reticulocyte count, blood culture, and any other indicated tests and, if there is no allergy, a dose of a long-acting cephalosporin (eg, ceftriaxone) should be administered intravenously (IV). If penicillin resistance is common in the community, and especially if meningitis is present, treatment with vancomycin is recommended. Patients should then be observed carefully for at least 2 hours as laboratory results are retrieved and any additional evaluation completed. All patients should have a chest x-ray as part of their assessment. Even immunized children taking penicillin should be managed urgently and receive empiric therapy. Children with high fever, pain, and/or ACS should be admitted to the hospital. The majority of children with fever can be managed on an ambulatory basis; clinical criteria published in 1993 were highly effective in identifying a higher-risk group of children best hospitalized and should be utilized by emergency department (ED) physicians for appropriate disposition of febrile children. Children with any of the following characteristics should be hospitalized to continue antibiotics pending results of the culture:
“toxic” appearance
temperature at or above 40°C
infiltrate on chest x-ray, abnormal oxygen saturation, tachypnea in excess of that attributable to fever, clinical signs of consolidation
white blood cell (WBC) count greater than 30 000/mm or less than 5 000/mm
platelet count less than 100 000/mm
hemoglobin less than 5 g/dL or more than 2 g/dL below baseline
history of sepsis due to S pneumoniae
poor oral intake, signs of dehydration
concurrent pain episode
Others who require admission include: any child without a reliable caretaker, source of primary care and/or hematology follow-up; no telephone or poor access to the hospital; unimmunized, noncompliant children. Others generally can be sent home. A hematologist should be called to ensure adequate follow-up and to obtain any further critical information that may be available. If discharged, the child must be reevaluated in the ED or at the hematology clinic 24 hours after administration of parental antibiotics. Depending on culture results and other factors, a second dose of cephalosporin, an oral course of antibiotics, or discontinuation of antibiotic therapy might be recommended. This decision should be made in conjunction with the hematologist.
Figure 11.2 ▪ Sickle Cell Anemia with Transient Aplastic Crisis.
Fever and rhinorrhea for 3 days followed by irritability were the presenting complaints of this infant whose hemoglobin value was 3 g/dL with reticulocytopenia. Aplastic crisis is caused by parvovirus B19 infection, and patients may present with weakness, listlessness, dizziness, and extreme pallor. (Photo contributor: Binita R. Shah, MD.)
Fever in a child with SCD must be considered a medical emergency to permit prompt empiric antibiotic therapy and prevent death/morbidity from pneumococcal sepsis.
Prompt empiric therapy is required even if the child has been immunized, is taking prophylactic penicillin, and/or has a “source” for the fever.
Criteria are available that permit most children to be discharged and managed on an ambulatory basis.
Pain is one of the most common manifestations of sickle cell anemia, and can occur in any part of the body. It is often associated with bone marrow infarction and may be accompanied by prominent inflammatory changes (warmth, tenderness, erythema) over the painful area, or there may be minimal or no physical findings. Pain may be due to “sludging” of sickle cells in the capillary bed with vascular obstruction and tissue ischemia/infarction; sickle cell vasculopathy and inflammatory mediators may contribute to tissue injury. However, the subjective complaint of pain is often unaccompanied by objective physical findings, and the patient must be relied on to assess analgesic response. There are no clinical, radiographic, or laboratory parameters proven to confirm or refute pain. Radiographs are generally not useful in assessment of acute pain; even with acute infarction, bone films will be normal for 7 to 10 days after onset. Nuclear medicine scans (gallium, indium, and bone or bone marrow) have been used to attempt to differentiate acute bone infarction from osteomyelitis but are also often not definitive and should not be ordered in the ED. Other potential causes of pain should be assessed. Patients with chest pain should be examined carefully for clinical findings of consolidation. They also must be continuously monitored for splinting/hypoventilation as a precipitant of ACS. Careful performance of the physical examination with auscultation for rales or diminished breath sounds is critical; clinical findings often precede radiographic findings. Tachypnea may be subtle, with shallow but rapid respiratory rate. Sickle cell patients with concurrent asthma may be at increased risk for ACS. Abdominal pain and/or distension may be a presenting symptom of ACS or sometimes a complication. Any patient with abdominal pain requires careful monitoring of pulmonary status and oxygen saturation. Other potential causes of abdominal pain need to be considered, both sickle cell–related (ie, cholecystitis, “gallstone,” pancreatitis) and those occurring in the general pediatric population. If appendicitis is suspected, hematology consultation must be obtained before surgery. Although acute infarction of cranial bones can occur, severe or persistent headache should prompt a careful neurologic assessment for meningitis or acute cerebral infarction and/or hemorrhage. Low-grade fever can complicate pain episodes, especially in patients with local inflammatory findings. A workup for possible infection should be done and empiric antibiotic therapy may be required. Prior to antibiotic administration, it may be appropriate to consult orthopedics regarding aspiration of the inflamed bone or joint to attempt to obtain material for culture.
Figure 11.3 ▪ Acute Pain Episodes (Vaso-Occlusive Crisis [VOC]) in Sickle Cell Anemia.
(A) Pain and swelling of the right upper arm as a manifestation of VOC. (B) Pain and swelling over the left medial clavicle as a manifestation of VOC. (C) Pain and swelling around elbow as a manifestation of VOC. (Photo contributor: Binita R. Shah, MD [A–C].) (D) Pain and swelling of lower extremity as a manifestation of VOC. (Reproduced with permission from Shah BR, Laude T: Atlas of Pediatric Clinical Diagnosis. WB Saunders, Philadelphia, 2000, p. 257.)
The patient’s assessment is the only tool available for adequate pain management and they should be asked to quantitate their pain using an assessment scale (eg, a numerical pain intensity scale [Visual Analogue Scale] or the Wong-Baker FACES scale for younger children). A numerical goal should be agreed upon, and patients reassessed and retreated at intervals until adequate control is achieved. Patients receiving opioid analgesia should also be assessed with a sedation scale and have the dosage modified as required. Patients should be monitored, most commonly with a pulse oximeter. Patients will often suggest what medications and dosages have provided relief on previous episodes; this information should be utilized in designing a treatment regimen. IV fluids are administered at least at a maintenance rate; most children with pain are somewhat dehydrated. If the patient is drinking liquids, decrease the IV fluid accordingly. However, aggressive hydration may be a risk factor for ACS, and patients with concurrent ACS generally receive only maintenance fluids or less. Most patients should receive ibuprofen every 6 hours by mouth and an initial dose of IV morphine sulfate. A patient should be reassessed in 30 minutes and if pain is poorly relieved and sedation acceptable, additional morphine should be given. Once relief is achieved, morphine should be given at 2- to 4-hour intervals to maintain adequate analgesia. An alternative to morphine is hydromorphone, which has a slightly longer duration of action given every 3 to 4 hours. Both morphine and hydromorphone are also used via patient-controlled analgesia (PCA), allowing the patient to titrate medication himself or herself to achieve pain control, avoiding dependence upon care providers and potential pseudo-addiction. The optimal dosing for PCA (generally a continuous infusion supplemented by demand doses by the patient) has not been established for children with SCD and use should be restricted to physicians/pain teams with experience. Ketorolac is a nonsteroidal anti-inflammatory medication that is not a respiratory depressant and may thus be especially useful in patients with chest or back pain. It is only approved for IV use in adolescents older than age 15 years. It should not be used with ibuprofen or by patients with renal disease. If pain is poorly controlled on usual doses of opioids and/or the need for parenteral analgesia continues, the patient should be admitted. If pain is, in the assessment of the patient, under control, it may be appropriate to substitute an oral analgesic prior to discharge to ensure continued adequacy of analgesia on discharge. The dose of morphine when changed from parenteral to oral administration needs to be increased 3-fold and hydromorphone 4-fold to achieve comparable analgesia. Alternatives include oxycodone for older children or codeine. A substantial minority of patients may not metabolically activate codeine and it may be ineffective. Codeine is often dispensed in combination with acetaminophen; parents should be reminded not to supplement with additional acetaminophen. Ibuprofen and/or acetaminophen should generally be continued with the oral opioid preparation. Patients should be provided with sufficient analgesia to last several days and be encouraged to follow up with the hematologist or primary care physician. Those who utilize the ED primarily and do not show evidence of an ongoing relationship with a health care provider should be referred for psychosocial assessment. Nonpharmacologic interventions should be encouraged, including psychosocial strategies (distraction or psychotherapy), behavioral strategies (deep breathing, relaxation, self-hypnosis), and physical strategies (heat, massage). Regular (10 puffs every 2 hours while awake) use of incentive spirometry is proven to reduce the incidence of nosocomial ACS and, especially if a prolonged stay in the ED is anticipated, should be prescribed. Patients with recurrent episodes of pain and/or ACS may be candidates for hydroxyurea therapy (after consultation with hematologist). Hydroxyurea is safe and effective in reducing the frequency of pain and ACS in children as young as age 9 months and convincingly improves life expectancy in adults.
Figure 11.4 ▪ Right Upper Quadrant (RUQ) Syndrome in Sickle Cell Anemia.
(A) Worsening jaundice and right-sided abdominal pain were the presenting complaint in this adolescent girl with sickle cell disease. Sickle cell-related causes of RUQ syndrome include cholecystitis, “gallstone,” pancreatitis and sickle cell hepatopathy. (B) Ultrasound shows a large stone within the gallbladder with acoustical shadowing. There is also sludge within the gallbladder lumen. (C) CT scan shows multiple calcified calculi within the gallbladder in a different patient presenting with right sided pain. (Photo contributors: Binita R. Shah, MD [A] and Mark Silverberg, MD [B, C].)
The patient is the only person who can assess his or her pain and may have a useful opinion as to the most effective analgesic regimen. Listen to the patient!
Do not administer placebo; response to placebo does not prove that the patient is not in pain.
Meperidine is a less effective pain reliever, has a higher potential for toxicity (neurotoxic), and its use is discouraged except perhaps in patients who are truly allergic to morphine (and thus hydromorphone and codeine as well).
Patients who received opioids for pain relief in the recent past or for more than a few days may develop pharmacologic tolerance to the drug and require higher doses for pain relief. Rapid cessation of opioid therapy after several days of treatment may result in withdrawal symptoms, sometimes manifested as recurrent pain. Opioid dosage should be tapered over several days in such cases.
Causes of pain other than those attributable to acute vasoocclusion should be excluded.
Acute chest syndrome (ACS) is defined as acute pulmonary findings in a child with sickle cell disease (SCD). These findings may include tachypnea, which is sometimes subtle; retractions; diminished (often asymmetrical) breath sounds; rales, vesicular sounds, or other signs of consolidation. Hypoxemia is often present and new pulmonary findings may be seen on chest radiograph. However, many patients present with clinical findings of ACS that precede abnormal radiographic findings by 24 to 48 hours. Because of multiple and sometimes overlapping etiologies, all children with ACS should be treated for both infectious and sickle cell–related etiologies. The most common identifiable infectious pathogens are atypical bacteria (Mycoplasma pneumoniae and Chlamydia pneumoniae); bacterial infection (including S pneumoniae) may occur in approximately 5% of cases. The most common identifiable noninfectious cause of ACS is pulmonary fat embolization from infarcted bone marrow; marrow infarction is a frequent cause of an acute pain episode. Transfusion therapy may be important in preventing multiorgan failure and death due to severe fat embolization syndrome (approximately 70% of children are ultimately transfused during a course of ACS). Abdominal pain and/or distension may be a presenting symptom of ACS or sometimes a complication. Any patient with abdominal pain requires careful monitoring of pulmonary status and oxygen saturation. Neurologic problems may occur because of embolization of bone marrow fat from the lungs to the brain or ischemia/infarction due to systemic hypoxemia and underlying cerebrovascular disease. There is a temporal association of ACS with stroke.
Figure 11.5 ▪ Acute Chest Syndrome.
(A, B) Cardiomegaly and progressive development of bibasilar infiltrates consistent with acute chest syndrome in a patient who presented with fever and abdominal pain. The worsening of respiratory status occurred in less than 24 hours. Maintain a high index of suspicion for ACS in any patient with SCD who presents with chest, back, or abdominal pain. (Photo contributor: John Amodio, MD.)
Examine patients carefully, especially those with fever, chest or back pain, and abdominal pain or distension; an accurate respiratory rate is simple and critical. A CBC with reticulocyte count is required. It often shows a significant drop in hemoglobin value from baseline, a decrease in platelet count, and an elevated number of nucleated RBCs. Other tests include arterial blood gases; an arterial-alveolar gradient measured in room air greater than 30 mm Hg suggests risk for a more severe clinical course, and it must be remembered that a normal Pco2 in a patient with respiratory distress is ominous and may indicate impending respiratory failure. Chest radiograph may initially be normal or involve one or several lobes and rapidly progress to “white-out” of one or both lungs. Pleural effusions may be present. As radiologic findings may lag behind clinical findings, treatment should precede confirmatory radiograph in children with symptoms and signs of ACS. A specimen for type and screening should be sent to the blood bank with the alert that the patient has SCD. Many blood banks will have a complete red cell phenotype on file to extend the compatibility profile; at a minimum, patients should receive red cells compatible with types C, E, and Kell (historically the most antigenic in sickle cell populations). Because most Rh (D)–negative Caucasian donors are C and E negative as well, if the need for blood is urgent Rh- and Kell-negative units can generally be released promptly and safely. Preserve hydration by offering maintenance fluids or less with close monitoring of intake and output (avoid pulmonary edema–induced worsening of ACS). Careful choice and dosing of analgesic therapy is needed to prevent hypoventilation secondary to splinting and/or sedation/respiratory depression (hypoventilation may lead to atelectasis and hypoxemia); ketorolac use may be desirable in older patients. Incentive spirometry, as prescribed for pain, should be offered, especially if a prolonged stay in the ED is anticipated. All patients with ACS should receive macrolide therapy to cover possible atypical bacteria. Though bacteria, including S pneumoniae, are uncommon pathogens, younger patients (especially nonimmunized) with high fever, high white cell count, or a toxic appearance may also be given antipneumococcal therapy pending culture results. Simple transfusion with packed RBCs is often given for a moderate to severe episode, especially when associated with a drop in hemoglobin concentration. Unless a prolonged stay in the ED is required and a patient is clinically distressed, transfusion should best be administered in the inpatient area. Simple transfusion rather than exchange should be the front-line therapy unless a patient is less anemic than average (ie, Hb > 9 g/dL) and thus cannot safely be given a simple transfusion because of viscosity concerns (posttransfusion Hb should never exceed 11 g/dL in an acutely ill, urgently transfused patient). Activation of various cytokines and upregulation of adhesion molecules are particular manifestations of an often robust and sometimes deleterious inflammatory response. Use of dexamethasone (given every 12 hours for four doses) attenuates the course of ACS but appears to be associated with a high readmission rate for pain shortly after recovery from ACS. An “asthma regimen” of prednisone for 5 to 7 days may be less associated with readmission and perhaps efficacious in reducing the need for transfusion; however, this regimen has not been assessed prospectively and should NOT be initiated in the ED. Because of its variable and often severe clinical course, all patients with ACS should be hospitalized, preferably in an ICU or well-observed bed with oxygen therapy and continuous cardiac and pulse oximetry monitoring. A pediatric hematologist should be consulted for management of a patient with ACS and in decisions about antibiotic coverage, transfusion, and steroid therapy. All patients who experience even a single episode of ACS should be made aware of the role of hydroxyurea therapy in potentially reducing the risk of recurrent ACS and other sickle cell complications.
Figure 11.6 ▪ Acute Chest Syndrome.
(A) Frontal radiograph showing cardiomegaly with a minimal ill-defined parenchymal infiltrate in the right lower lobe in a patient presenting with chest pain, cough, and fever. (B) A repeat radiograph taken 6 hours later shows near complete opacification of the right hemithorax, with a mediastinal shift to the contralateral side resulting in severe respiratory distress and hypoxemia. These findings may represent a large consolidation with or without pleural effusion. There is also levoscoliosis most likely secondary to splinting from the right sided process. (C) Pallor. A significant drop in hemoglobin value from baseline often occurs during ACS. (Photo contributor: Binita R. Shah, MD.)
A careful physical examination, with particular attention to respiratory rate and effort, is critical in diagnosis of ACS.
Fever may be the only early manifestation of ACS; all febrile sickle cell patients should have a chest radiograph as part of their evaluation, even if respiratory signs and symptoms are not identified.
Clinical or radiologic diagnosis of ACS mandates hospitalization. Radiographic findings may lag and need not be present to make a clinical diagnosis of ACS.
All patients with ACS and hypoxia and/or tachypnea should receive supplemental oxygen until (and after!) their transfer to the inpatient unit.
The blood bank should always be aware of a sickle cell diagnosis, so extended antigen-matching, at least to include C, E, and Kell antigens, is done.
Although corticosteroid therapy may be a useful adjunct to care, treatment should not be initiated in the ED without specific discussion with the pediatric hematologist.
Stroke affects 5% to 10% of children with sickle cell disease (SCD). The majority of ischemic strokes are due to watershed infarcts resulting from sickle cell vasculopathy of major cerebral vessels. It is speculated that abnormal adherence of sickled red cells and white cells to the vascular endothelium and perhaps nitric oxide depletion result in vessel injury and intimal hyperplasia. Hyperplasia leads to gradual stenosis and ultimately occlusion of the large- and middle-caliber cerebral arteries, particularly the middle cerebral artery; often multiple vessels are involved. Approximately 70% to 90% of children with SCD who have strokes due to infarction have cerebrovascular disease of major vessels. An additional 10% to 30% may have microvascular disease; typically these lesions are in deep periventricular white matter. Hemorrhagic stroke (subarachnoid and/or intracerebral hemorrhage) occurs less commonly during childhood, but becomes progressively more common with increasing age. A sudden onset of hemiparesis is the most common presentation in children. Weakness or numbness of an extremity or a painless limp may be patient/parent complaints. Cranial neuropathies are sometimes seen, but infarction in the brainstem and areas fed by the posterior circulation (cerebellum) are uncommon. Patients may have bilateral findings at the time of initial diagnosis because of previously unrecognized infarcts. Intracranial hemorrhage can present with headache, although headache is not often seen in infarctive strokes. Patients with transient ischemic attacks (TIAs) may have similar symptoms that resolve spontaneously within 24 hours of onset. TIAs are associated with an increased risk of subsequent stroke, and patients with TIA should be investigated carefully for underlying cerebrovascular disease. Transcranial Doppler ultrasonography (TCD) is a screening method to identify children at increased risk for stroke, who can then receive preventive transfusion therapy. Screening appears to substantially reduce stroke incidence and is recommended at least annually for all children with HbSS or sickle β-thalassemia from age 2 through 16 years. Prompt TCD screening may be useful in an individual patient with TIA or equivocal neurologic findings to establish stroke risk but must be performed by an examiner familiar with the screening protocol and interpretation required for children with SCD.
Figure 11.7 ▪ Stroke in Sickle Cell Anemia.
(A) T2-weighted magnetic resonance imaging (MRI) scan of the brain shows areas of increased signal intensity involving the gray and white matter of the left parietal lobe that are consistent with an acute infarct (arrow). (B) MRI angiography of the circle of Willis in the same patient shows areas of stenosis in the left anterior cerebral artery and proximal middle cerebral artery (two open arrows). The left posterior communicating artery shows less signal intensity (closed arrow) compared with the right, a finding consistent with decreased flow. (Reproduced with permission from Shah BR, Laude TL: Atlas of Pediatric Clinical Diagnosis. WB Saunders, Philadelphia, 2000, p. 265.)
Figure 11.8 ▪ Strokes in Sickle Cell Anemia.
(A, B) An 8-year-old girl presented with new-onset right-sided weakness. Magnetic resonance images show old strokes (A, arrow) in the left corona radiata (increased signal with encephalomalacia and enlargement of left lateral ventricle). A new ischemic stroke (B, arrow) is seen in the left parietal region (increased signal involving grey and white matter in the second image). (C, D) A 17-year-old girl presented with syncope and headache. CT scan of head (A) reveals subarachnoid hemorrhage (hyperdensity in the basal cisterns, arrow), with enlargement of temporal horns of lateral ventricle. Angiogram (with 3D reconstruction; D) revealed a large aneurysm at the top of the basilar artery (arrow). (Photo contributor: Geetha Chari, MD.)
A pediatric hematologist and a pediatric neurologist should be consulted emergently regarding a patient with suspected stroke to confirm the neurologic findings and initiate therapy. Patients should be given oxygen and specimens sent for CBC, coagulation screen, and alloantibody screening. A specimen should also be sent for complete red cell phenotyping to facilitate extended antigen-matching of blood and ultimately chronic transfusion therapy. A CT scan of the brain is generally done urgently to rule out intracranial hemorrhage. CT scans are relatively insensitive for infarction, although sensitivity improves after 3 to 4 days. Patients who are found to have intracranial bleeding on CT scan should have urgent neurosurgical consultation. If conventional angiography is needed, it is best done after exchange transfusion (see below) and using low ionic strength contrast medium. A diffusion-weighted magnetic resonance imaging (MRI) should be done to confirm cerebral ischemia/infarction, with a magnetic resonance angiography (MRA) done concurrently to establish the extent of cerebrovascular disease. It is convention that patients with newly diagnosed stroke be treated with exchange transfusion; recovery is often substantial after the procedure. Although no prospective trials have compared exchange transfusion to simple transfusion repeated at weekly intervals to achieve the traditional goal of <30% HbS, a retrospective review suggested patients exchanged promptly had a lower risk of stroke recurrence. A simple transfusion may be given to patients with Hb <9 g/dL while preparing for exchange. An exchange transfusion requires admission to the hospital, most appropriately to an intensive care unit, and can be done manually or by erythrocytapheresis. TIA patients should be transfused while awaiting complete evaluation for cerebrovascular disease and the decision as to whether to continue a chronic transfusion program. Most patients who are found to have a new acute cerebral infarction, or TIA with significant vascular disease, are placed on a chronic transfusion program for at least several years. Although anticoagulation and thrombolytic therapy are increasingly used in adults with acute stroke, appropriate use of these therapies has not been established in patients with SCD; standard therapy is exchange transfusion.
The most common cause of stroke in children with SCD is cerebral infarction due to vasculopathy of the major cerebral vessels.
A painless limp or weakness (hemiparesis) is the most common presentation of stroke. In younger children, a limp or unwillingness to walk may occasionally be mistakenly diagnosed as a pain episode. A lack of complaint of pain, local tenderness or inflammatory findings in the extremities should prompt neurologic assessment.
All patients with SCD presenting with a seizure or neurologic symptoms and signs must be assessed for possible stroke.
Stroke in patients with SCD usually develops as an isolated event; however, it may occur during other types of crisis (eg, aplastic crisis, ACS, or splenic sequestration).
Priapism is defined as an unwanted painful penile erection. Clinically it can be a single prolonged (24 hours to several days) episode or shorter, often recurrent, “stuttering” episodes. Prolonged episodes are generally low-flow and ischemic, presumably because of sludging and stasis of blood in the cavernosal spaces. Ischemia and infarction will injure cavernosal smooth muscle and ultimately result in fibrosis and impotence. The pathophysiology of high-flow priapism is not clear. It may be related to vascular disease and autonomic dysfunction and/or nitric oxide depletion with derangement of normal regulatory pathways. Stuttering episodes are more commonly seen in prepubertal males and the prognosis is probably better than in older patients with low-flow episodes; however, in a large series from Jamaica, all patients with stuttering ultimately did have a prolonged episode lasting longer than 24 hours. Noninvasive methods used to assess penile perfusion include radionuclide penile scan and Doppler ultrasonography. The glans and corpus spongiosum are generally spared in sickle cell–related priapism, providing a rationale for surgical shunting. Tricorporal priapism is associated with a more prolonged, difficult course and more severe systemic disease.
Figure 11.9 ▪ Priapism in Sickle Cell Anemia.
(A) An adolescent patient presented with a swollen, edematous, and very tender penile erection of 5 hours’ duration. The diagnosis of priapism is usually made by clinical examination. Both corporal bodies are turgid and tender, while the glans penis and spongiosum are usually spared. (B) A 21-gauge butterfly needle was placed in the corpora cavernosum after lidocaine injection, aspiration and irrigation with saline and phenylephrine was performed, with subsequent resolution of the priapism. (Photo contributor: Binita R. Shah, MD.)
Emergent consultation with urology and pediatric hematology is needed for patients who have a priapism episode lasting >2 hours; many of these episodes will extend to 24 hours and beyond without intervention. Episodes lasting more than 48 hours are associated with a high incidence of subsequent impotence; intervention should begin as early as possible after a patient appears in the ED. Patients should be treated with fluids at 1.5 times maintenance and given adequate analgesia (ie, morphine sulfate). Aspiration of the corpora cavernosum and irrigation with approximately 10 mL of a 1:1 000 000 dilution of epinephrine should be performed by an experienced urologist within a few hours of presentation as it nearly always achieves at least temporary detumescence. Depending on the patient, it is performed with local or regional anesthesia and/or moderate sedation; younger children may require admission to the hospital for deep sedation/general anesthesia. The first blood aspirated may be sent for analysis of pH, Pco2, and Po2 to establish cavernosal flow status. If aspiration fails or priapism recurs after brief detumescence, the patient should be hospitalized. Although there is no proven benefit from blood transfusion in the acute management of priapism, it may be useful to transfuse (simple transfusion in most cases) after an unsuccessful aspiration and prior to a repeat; subsequent aspiration will then allow “normal” transfused blood to enter the cavernosal spaces. Blood transfused to a patient during a low-flow episode will not enter the cavernosae and is unlikely to be effective. If detumescence occurs after initial aspiration, the patient may be discharged from the ED. Pseudoephedrine 30 to 60 mg at night may reduce risk of recurrent stuttering episodes. Recurrent priapism episodes that resolve spontaneously or with aspiration should be referred to a hematologist and/or urologist familiar with the disorder. Additional preventive treatment for recurrent priapism may include chronic transfusion therapy to maintain HbS <30% for 6 to 12 months, hydroxyurea therapy, stilbestrol therapy (unacceptable side effects), injections of leuprolide (suppresses production of testosterone), or oral finasteride.
