Automated erythrocytopheresis for relief of priapism in sickle cell hemoglobinopathies

Red cell exchange for patients with sickle cell disease: an international survey of current practices

INTRODUCTION

Red cell exchange (RCE) therapy is increasingly used to treat patients with acute or chronic manifestations of sickle cell disease (SCD). However, little is known regarding the most safe and effective practice parameters associated with this particular therapy.

METHODS

A SCD subcommittee of members of the American Society for Apheresis (ASFA) developed a 122-question survey and administered it via email to other ASFA members. The survey inquired about clinical indications for treatment, practice patterns, and transfusion policies for RCE when used for patients with SCD.

RESULTS

Ninety-nine distinct institutions completed the survey. Twenty-one (21%) were from outside of the US. Twenty-two (22%) provided chronic transfusion therapy to >10 patients, and both adult (25%) and pediatric-focused services (20%) were represented. Common acute indications for RCE included acute chest syndrome, acute ischemic stroke, and pre-surgical prophylaxis. Common chronic indications included primary stroke prophylaxis, secondary stroke prophylaxis, and recurrent acute chest syndrome. Respondents most commonly set a post-RCE treatment target of 30% for the hematocrit and hemoglobin S levels, regardless of the therapeutic indication. Units for RCE were phenotypically matched in 95% of cases. About 40% of respondents reported using isovolemic hemodilution.

CONCLUSIONS

This survey solicited the current practice variations in RCE from a diverse range of practice sites. Many sites reported similar practice patterns and challenges but some variations emerged. To our knowledge, this survey represents the largest and most in-depth investigation of the use of RCE for patients with SCD, and could inform future studies in the field.

Sickle cell disease: a review for the internist

Sickle cell disease (SCD) is the most important hemoglobinopathy worldwide in terms of frequency and social impact, recently recognized as a global public health problem by the World Health Organization. It is a monogenic but multisystem disorder with high morbidity and mortality. Vaso-occlusion, hemolytic anemia and vasculopathy are the hallmarks of SCD pathophysiology. This review focuses both on "time-dependent" acute clinical manifestations of SCD and chronic complications commonly described in adults with SCD. The review covers a broad spectrum of topics concerning current management of SCD targeted at the internists and emergency specialists who are increasingly involved in the care of acute and chronic complications of SCD patients.

Recommendations for the use of red blood cell exchange in sickle cell disease

Sickle cell disease (SCD) is a genetic disorder characterised by a single mutation of the beta globin gene, causing the production of an abnormal haemoglobin called sickle haemoglobin (HbS). In its deoxygenated form, HbS polymerises, causing major rheological disorders, which presents clinically as periodic vaso-occlusive crises, chronic haemolysis and chronic vascular dysfunction. Patients often resort to a background treatment, and transfusion remains the cornerstone in the management of the disease, significantly reducing morbidity and mortality. The aim of red blood cell exchange (RBCX) is to improve tissue oxygenation by increasing haemoglobin levels while lowering HbS levels. RBCX can be performed by manual or automated exchange, and each technique has its own set of advantages and disadvantages. This article will outline the transfusion indications for the main complications of SCD, as well as the most appropriate strategy to use.

Myth: Blood transfusion is effective for sickle cell anemia—associated priapism

Objective:

Priapism is a recognized complication of sickle cell anemia (SCA). When initial conventional treatments fail, simple or exchange blood transfusion has been advocated as a secondary intervention. However, recent literature suggests this may not be an effective therapy and may have significant neurologic sequelae. This paper reviews and summarizes the effectiveness and risks of blood transfusion compared with conventional priapism therapy.

Methods:

All relevant papers identified from a MEDLINE search were systematically examined for data related to the use of blood transfusion in the setting of priapism due to SCA. The effectiveness of conventional therapy was compared with transfusion therapy using the outcome of “time to detumescence” (TTD). In addition, papers documenting adverse neurologic sequela were reviewed and summarized.

Results:

Forty-two case reports were identified containing complete information with regard to patient age and TTD. The mean TTD was 8.0 days with conventional therapy (n= 16) and 10.8 days with blood transfusion therapy (n= 26). Adverse neurologic sequelae from blood transfusion therapy was described in 9 cases, with long term outcomes ranging from complete resolution to severe residual deficits.

Conclusion:

The current literature does not support the contention that blood transfusion is an effective therapy in the treatment of priapism due to SCA, as defined by an acceleration of TTD. In fact, numerous reports suggest that serious neurologic sequelae may result from this treatment. We feel the routine use of this therapy cannot be recommended.

Red cell exchange: special focus on sickle cell disease

The primary function of red blood cells (RBCs) is to deliver oxygen from the lungs to tissues. Tissue hypoxia occurs when the oxygen-carrying capacity of RBCs is compromised due primarily to 3 causes: (1) a reduction in circulating RBC mass, (2) an increase in circulating RBC mass, or (3) abnormal hemoglobin (Hb) that either does not sufficiently release oxygen to tissues (high-oxygen-affinity hemoglobin) or occludes the microvasculature due to deformed RBCs (sickled RBCs). To improve oxygenation in patients with reduced or increased RBC mass, RBC administration (simple transfusion) or RBC removal (RBC depletion) is performed, respectively. However, for patients with abnormal Hb, RBCs containing abnormal Hb are removed and replaced by healthy volunteer donor RBCs by red cell exchange (RCE). RCE can be performed by manual exchange or by automated exchange using a blood cell separator (erythrocytapheresis). In this review, indications for RCE in sickle cell disease using the evidence-based American Society for Apheresis categories(1) are presented and the rationale for RCE in each disorder are discussed. Simple transfusion versus RCE and manual RCE versus automated RCE are compared. Finally, this review briefly presents some of the challenges of performing erythrocytapheresis in small children and discusses various choices for central venous access during RCE.(2.)

Transfusion Management in Sickle Cell Disease

Sickle cell disease (SCD) is the most commonly inherited hemoglobinopathy in the United States. Blood transfusion is a critical part of the multidisciplinary approach necessary in the management of SCD; however, blood transfusions are not without complications. The successful use of transfusion as a treatment strategy in SCD requires the critical review and knowledge of transfusion methods, generally accepted indications, clinical situations in which transfusion generally is not considered, the selection of blood products, and strategies to prevent transfusion-related complications.

The role of red blood cell exchange transfusion in the treatment and prevention of complications of sickle cell disease

Patients with sickle cell disease have abnormal red blood cells (RBCs). This can cause chronic hemolytic anemia and vaso-occlusion leading to tissue hypoxemia and organ dysfunction. RBC exchange transfusion can, without increasing the whole-blood viscosity, quickly replace abnormal erythrocytes with normal and raise the hematocrit resulting in improved delivery of oxygen to hypoxic tissues. Unfortunately, transfusion can also be associated with complications. This paper reviews the role of transfusion, both simple and exchange, in the treatment and prevention of sickle-related complications. The benefits of exchange versus simple transfusion and transfusion versus alternative therapies are discussed.

Do automated red cell exchanges relieve priapism in patients with sickle cell anemia?

Priapism is a dramatic, painful complication for some men afflicted by sickle cell anemia. Although the natural history remains unclear, many believe replacing the patient's abnormal red blood cells (RBCs) with normal RBCs by apheresis is effective. However, no controlled trials have demonstrated its effectiveness. We exchanged 7 men after medical management failed. All procedures reduced sickle hemoglobin levels to < 30%. Two patients underwent emergency automated red cell exchanges without any detumescence or reduction of pain. The remaining 5 patients were exchanged non-emergently; 4 experienced no detumescence or relief of pain. One adult experienced resolution 8 h postexchange. However, he had a history of "stuttering" priapism. All required decompression procedures. Automated RBC exchanges were not effective in achieving detumescence or reducing pain.

Outpatient penile aspiration and epinephrine irrigation for young patients with sickle cell anemia and prolonged priapism

The optimal management of prolonged priapism for patients with sickle cell anemia (SCA) has not been established. We prospectively studied in an outpatient setting the efficacy and safety of a procedure that employs aspiration of blood from the corpora cavernosa and irrigation with a dilute epinephrine solution under local anesthesia to relieve priapism in young patients with SCA. If hydration and analgesics failed to produce detumescence or if priapism had lasted >4 hours, the protocol was activated in the emergency room or clinic. Fifteen patients with homozygous SCA (Hb SS) were treated on 39 occasions; 10 patients were treated once, 1 patient twice, 2 patients 3 times, 1 patient 6 times, and 1 patient 15 times. Median age of patients at first treatment was 14.3 years (range, 3.9-18.3 years). The procedure was successful in producing immediate detumescence on 37 of 39 occasions (95% efficacy, 95% confidence intervals (CI): 81%-99%). No serious immediate or long-term side effects were observed. None of the patients who demonstrated detumescence required hospitalization. The 2 patients whose priapism persisted after aspiration and irrigation presented with episodes lasting >24 hours. All evaluable patients whose priapism resolved after aspiration and irrigation self-reported normal erectile function at a median of 40 months (range, 3-58 months) after the last procedure. Thus, aspiration of the corpora cavernosa followed by irrigation with dilute epinephrine is effective in producing immediate and sustained detumescence and should be the initial therapy employed for patients with SCA and prolonged priapism. (Blood, 2000; 95:78-82)

Outpatient penile aspiration and epinephrine irrigation for young patients with sickle cell anemia and prolonged priapism

The optimal management of prolonged priapism for patients with sickle cell anemia (SCA) has not been established. We prospectively studied in an outpatient setting the efficacy and safety of a procedure that employs aspiration of blood from the corpora cavernosa and irrigation with a dilute epinephrine solution under local anesthesia to relieve priapism in young patients with SCA. If hydration and analgesics failed to produce detumescence or if priapism had lasted &gt;4 hours, the protocol was activated in the emergency room or clinic. Fifteen patients with homozygous SCA (Hb SS) were treated on 39 occasions; 10 patients were treated once, 1 patient twice, 2 patients 3 times, 1 patient 6 times, and 1 patient 15 times. Median age of patients at first treatment was 14.3 years (range, 3.9-18.3 years). The procedure was successful in producing immediate detumescence on 37 of 39 occasions (95% efficacy, 95% confidence intervals (CI): 81%-99%). No serious immediate or long-term side effects were observed. None of the patients who demonstrated detumescence required hospitalization. The 2 patients whose priapism persisted after aspiration and irrigation presented with episodes lasting &gt;24 hours. All evaluable patients whose priapism resolved after aspiration and irrigation self-reported normal erectile function at a median of 40 months (range, 3-58 months) after the last procedure. Thus, aspiration of the corpora cavernosa followed by irrigation with dilute epinephrine is effective in producing immediate and sustained detumescence and should be the initial therapy employed for patients with SCA and prolonged priapism. (Blood, 2000; 95:78-82)

Gonadotropin-releasing hormone analogues in the treatment of sickle cell anemia-associated priapism

Priapism secondary to sickle cell anemia has been treated with a variety of therapeutic regimens. Recurrent sickle cell priapism is common and in many cases results when detumescence has not been achieved reliably. We report on a patient with sickle cell disease and recurrent priapism who was treated successfully for more than a year with monthly gonadotropin-releasing hormone analogue therapy after failure of standard medical management.

Multisystem damage associated with tricorporal priapism in sickle cell disease

PURPOSE

Priapism is an uncommon but debilitating complication of sickle cell disease (SCD). Recent observations among adult males regarding the abysmal failure of medical and surgical therapy encouraged us to review our 25-year experience identifying the prognostic features that might determine outcome.

PATIENTS AND METHODS

As part of a prospective 25-year longitudinal demographic and clinical cohort study, a subset of 38 (8.2%) patients with priapism were identified among a cohort of 461 men with SCD. The patients with priapism were compared with the nonaffected men with respect to severity of disease expression, hematologic status, beta s globin gene haplotype, and the incidence of sickle-related major organ failure. The influence of the treatment modalities on outcome was also evaluated.

RESULTS

Priapism occurred as a single episode in 24 patients, and in 14 as temporally clustered repeat episodes. Eighty-seven percent of those with priapism had sickle cell anemia (SS), an increased risk as compared with other variants of SCD (p = < 0.05). There were two distinct age-related patterns of disease expression. Eight patients were prepubertal; they experienced shorter episodes, involvement of the corpora cavernosa only, few recurrent episodes, and a good prognosis for future erectile function. Non-surgical therapy in children was associated with excellent results. In contrast, the 29 postpubertal adults often had involvement of the corpora cavernosa and corpus spongiosa (tricorporal disease) and half had prolonged episodes that lasted longer than 8 days. One pubescent patient had repeated episodes and became impotent. Prolonged or repeated episodes eventuated in impotence in 56%. Surgical intervention was not beneficial. Sickle cell-related organ failure such as stroke, chronic restrictive lung disease, chronic renal failure, and nonhealing leg ulcers was observed more frequently in men who had priapism. Death occurred in nine adult patients (25%) within 5 years of the first episode of priapism.

CONCLUSION

Priapism in adult males identifies those at high risk for other sickle cell-related organ failure syndromes and, as such, is another complication indicative of severe disease. The dismal prognosis in SS adults requires better understanding of the precise pathophysiology of low-flow tricorporal priapism. Clarification of the mechanisms inducing the priapic state should lead to specific therapeutic maneuvers and an improved prognosis for this disabling condition.

Neurologic events after partial exchange transfusion for priapism in sickle cell disease

We describe six boys with homozygous sickle cell disease, aged 7 to 13 years, in whom acute, severe neurologic abnormalities developed 1 to 11 days after partial exchange transfusion was performed to treat priapism that was unresponsive to more conservative therapy. Hemoglobin levels were 10.5 to 13.4 gm/dl (mean 12.1 gm/dl), and hemoglobin S levels were 18% to 33% (mean 27%) before the onset of neurologic complications. Severe headache was the initial finding in five patients, four of whom had increased intracranial pressure and three of whom required tracheal intubation and hyperventilation. Four patients had seizures; three had focal neurologic deficits for more than 24 hours. Cerebral arteriography demonstrated vascular abnormalities, including irregularity, stenosis, and complete occlusion of vessels. Patients treated with regular erythrocyte transfusions had no recurrence of neurologic signs or symptoms when hemoglobin S levels were kept at 30% to 50%. The occurrence of serious neurologic complications after partial exchange transfusion in patients with homozygous sickle cell disease from three centers indicates the possibility of a causal relationship between the events. Early and thorough investigation of neurologic symptoms, especially severe headache, is warranted in this clinical setting.

Management of patients with sickle cell disease

The ever-increasing body of information regarding the molecular pathogenesis of sickle cell disease has raised expectations that a specific and effective therapy could be devised to inhibit polymerization of hemoglobin S. Despite an intense international research effort, this goal has not yet been realized. Supportive care continues to be the mainstay in the management of patients with sickle cell anemia. Empiric measures were used in early attempts to treat sickle cell anemia. Herrick reported gratifying improvement after "rest, nourishing food, the administration of iodide, arsenic, thymol and the application of boric ointment to leg ulcers." Many of these suggestions are similar to those of today. Several factors have significantly improved the prognosis of patients with this disease. Improved medical care, genetic counseling, and universal neonatal screening have directly resulted in improved outcome. Molecular biologic techniques have allowed us to approach this disease in a pathophysiologic way. Now we can envision antenatal diagnosis with the use of molecular probes and treatment by gene amplification. Still, however, the most important and challenging link in the chain between the biology of the disease and the clinical sequelae is an astute and interested physician who must remain objective at all times.

Priapism in sickle cell anaemia: a case report

Priapism is an unusual and distressing complication of sickle cell anaemia and its management has been varied and generally unsatisfactory. We report priapism in a Libyan boy with sickle cell anaemia, managed successfully by blood transfusion.