eMedicine Specialties > Pediatrics: Cardiac Disease and Critical Care Medicine > Cardiology
Heterotaxy, Asplenia
Updated: Apr 23, 2009
Introduction
Background
Asplenia is a heterogeneous disease that primarily affects the asymmetric organs, including the heart, liver, intestines, and spleen. The first published description of asplenia appeared in 1826. Primary manifestations of this disease include cyanotic congenital heart disease and intestinal malrotation.
Transverse ultrasonogram in a patient with asplenia. This image demonstrates the aorta and vena cava on either side of the midline, an appearance that simulates solitus anatomy.
Pathophysiology
The exact cause of asplenia has not been defined but appears to be multifactorial, with some familial predisposition. Embryologically, it results from failure of development of right-left asymmetry.1 All thoracic and abdominal organs can be affected; however, other than the anatomic abnormalities, the function of these organs is affected minimally.2
Cardiac manifestations can range from minor to severe and are related to incomplete or impaired rotation of the heart. Common cardiac findings include persistence of a left-sided superior vena cava (SVC), anomalous pulmonary venous return, common atrium, endocardial cushion defects, and double outlet right ventricle. In addition, bilateral right atrial appendages may be present in at least 20% of patients with asplenia, and their presence is diagnostic of this syndrome. Other thoracic findings include bilateral morphologic right bronchi and trilobed lungs.3
Abdominal findings can include asplenia, transverse liver, and intestinal malrotation.4 Biliary tract abnormalities have also been described but are rarely of clinical significance.
Frequency
United States
Asplenia has a prevalence of less than 0.1% but may account for as much as 1% of the newborn mortality rate. Case reports of familial predisposition are noted, but no clear inheritance pattern or gene has been identified. Anatomic findings have been variable in the families described.
Mortality/Morbidity
Without surgery, the mortality rate of asplenia is 95% in the first year of life. Palliative cardiac surgery improves the survival rate, particularly during infancy, but the 5-year mortality rate remains as high as 50%. Mortality can result from congenital heart disease, intestinal malrotation, or sepsis. In one large retrospective review from Canada, the 1-year mortality rate was 80%.
Race
No predilection based on race has been reported.
Sex
No predilection based on sex has been reported.
Age
Heterotaxy occurs in utero, and the onset of clinical symptoms may be during the neonatal period or later in life, depending on the exact cardiac and visceral lesions.
Clinical
History
Patients with asplenia usually present with symptoms of congenital heart disease in the newborn period. The most common presenting symptom is cyanosis, but murmurs and signs of congestive heart failure can also be presenting signs. A small percentage of patients present with abdominal symptoms or are identified because of an incidental finding of situs abnormalities (eg, dextrocardia, intestinal malrotation). Typically, patients presenting after the newborn period do not have significant congenital heart disease.
Physical
Cyanosis and/or congestive heart failure are the most common physical findings in patients who present in the newborn period. A transverse liver or dextrocardia is often present. Patients who present after the newborn period have predominantly normal physical examination findings, other than a transverse liver and/or dextrocardia. Patients who present with symptoms of malrotation can present with an acute abdomen caused by volvulus.
Causes
The causes of asplenia are unknown, but they appear to be multifactorial and may include inherited predisposition, teratogenic factors, or infection.5,6 No racial, sexual, or socioeconomic predispositions are noted. Although familial cases have been reported, no genes or loci have been identified. Reported patterns of inheritance have been diverse. In several families with multiple affected children, parental consanguinity is present, or rarely an autosomal recessive inheritance pattern is observed. In at least one family, an X-linked inheritance pattern was reported, with the disease present in 11 related males over 2 generations. Different forms of heterotaxy, including asplenia and polysplenia, may occur within the same family.
The molecular basis for heterotaxy may relate to defects in genes responsible for laterality, such as the growth factor genes: nodal, activin, and lefty.
Differential Diagnoses
Acidosis, Metabolic
Dextrocardia
Heterotaxy, Polysplenia
Transposition of the Great Arteries
Other Problems to Be Considered
Kartagener syndrome
Workup
Laboratory Studies
- Useful laboratory studies in asplenia include a CBC count with peripheral smear to assess for Howell-Jolly bodies and evidence of impaired splenic function.
- ABG to assess for cyanotic heart disease may also be indicated.
Imaging Studies
- Complete echocardiography is indicated in any patient with suspected asplenia to rule out associated congenital heart disease.
- Routine chest radiography is indicated to determine the cardiac size and location, to assess the bronchial anatomy, and to assess abdominal situs.
- In addition, an upper GI study has been proposed as a routine study in asplenic patients because of the high incidence of intestinal malrotation and the risk of volvulus.
Other Tests
- Liver-spleen scanning is indicated to confirm the presence of functional splenic tissue.
- A 12-lead ECG is helpful in assessing patients with asplenia because an abnormal P wave axis is common, and conduction system abnormalities, including complete heart block, sick sinus syndrome, and supraventricular tachycardia (SVT), may occur, although they are less common than in polysplenia.
- Additional studies of cardiac conduction may be indicated based on the clinical setting and ECG findings; in particular, 24-hour Holter monitoring may be recommended.
Procedures
- Patients presenting with cardiac malformations often require cardiac catheterization on one or more occasions. In the newborn period, cardiac catheterization may be indicated to assess systemic and pulmonary venous connections, if this information cannot be obtained from echocardiography. Access can often be achieved through the femoral vein or the umbilical vein, although umbilical venous cannulation is more difficult in patients with asplenia than in those with most other congenital malformations. Venous access from the umbilicus or femoral vein is usually sufficient to perform both a right-heart and left-heart catheterization.
- Later, cardiac catheterization may be indicated to determine individual candidacy for surgical intervention. Indications for catheterization may include assessment of pulmonary vascular resistance before palliation with a cavopulmonary connection. Assess pulmonary venous drainage in patients with unobstructed anomalous pulmonary venous return. In such cases, ruling out mild obstruction to pulmonary venous return, as is often observed on anomalous return to a confluence behind the right atrium or to the proximal superior vena cava (SVC), is important. Other indications for cardiac catheterization include assessment of ventricular size and visualization and potential embolization of aortopulmonary collateral vessels. Finally, electrophysiological testing may be indicated based on the clinical rhythm presentation.
Treatment
Medical Care
Medical therapy in asplenia is typically directed at the findings of the initial evaluation. Anticongestive medication is often beneficial preoperatively in patients with significant left-to-right shunts. Patients with functional asplenia require long-term antibiotic prophylaxis and the pneumococcal vaccine.
Surgical Care
Surgical care is also directed at the findings of the initial evaluation. Patients with significant cardiac disease may require staged palliation or definitive repair. Patients with biliary atresia may require initial palliative surgery followed by liver transplantation.
Consultations
Patients with heterotaxy should have a comprehensive evaluation by a pediatric cardiologist. Depending on the clinical circumstances, an assessment by a pediatric gastroenterologist, pediatric cardiac surgeon, pediatric cardiac electrophysiologist, and/or pediatric anesthesiologist may be warranted.
Medication
Patients with asplenia who have congestive cardiomyopathy with significant left-to-right shunts may benefit from treatment for congestive heart failure. In patients with functional asplenia, pneumococcal vaccine and antibiotics for subacute bacterial endocarditis (SBE) prophylaxis are necessary. Antibiotic prophylaxis is administered to patients before procedures that may cause bacteremia are performed. For more information, see Antibiotic Prophylactic Regimens for Endocarditis.
Diuretic agents
These agents promote excretion of water and electrolytes by the kidneys. They are used to treat heart failure or hepatic, renal, or pulmonary disease when sodium and water retention has resulted in edema or ascites. They may be used as monotherapy or in combination to treat hypertension.
Furosemide (Lasix)
Used to treat edema. Increases excretion of water by interfering with chloride-binding cotransport system, which, in turn, inhibits sodium and chloride reabsorption in ascending loop of Henle and distal renal tubule. Dose must be individualized to patient. Depending on response, administer at increments of 20-40 mg, no sooner than 6-8 h after previous dose, until desired diuresis occurs. When treating infants, titrate with 1-mg/kg/dose increments until satisfactory effect achieved.
Dosing
Adult
20-80 mg/d PO/IV/IM; may titrate up to 600 mg/d for severe edematous states
Pediatric
3-6 mg/kg/d PO divided tid
Interactions
Metformin decreases furosemide concentrations; furosemide interferes with hypoglycemic effect of antidiabetic agents and antagonizes muscle-relaxing effect of tubocurarine; auditory toxicity appears to be increased with coadministration of aminoglycosides and furosemide; hearing loss of varying degrees may occur; anticoagulant activity of warfarin may be enhanced when taken concurrently with this medication; increased plasma lithium levels and toxicity are possible when taken concurrently with this medication
Contraindications
Documented hypersensitivity; hepatic coma; anuria; state of severe electrolyte depletion
Precautions
Pregnancy
C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus
Precautions
Perform frequent serum electrolyte, carbon dioxide, glucose, creatinine, uric acid, calcium, and BUN determinations during first few months of therapy and periodically thereafter
Spironolactone (Aldactone)
For management of edema resulting from excessive aldosterone excretion. Competes with aldosterone for receptor sites in distal renal tubules, increasing water excretion while retaining potassium and hydrogen ions.
Dosing
Adult
25-200 mg/d PO divided q12-24h
Pediatric
1-3 mg/kg/d PO divided tid
Interactions
May decrease effect of anticoagulants; potassium and potassium-sparing diuretics may increase toxicity of spironolactone
Contraindications
Documented hypersensitivity; anuria; renal failure; hyperkalemia
Precautions
Pregnancy
D - Fetal risk shown in humans; use only if benefits outweigh risk to fetus
Precautions
Caution in renal and hepatic impairment
Inotropic agents
Positive inotropes increase the force of contraction of the myocardium and are used to treat acute and chronic congestive heart failure. Some may also increase or decrease the heart rate (eg, positive or negative chronotropic agents), provide vasodilatation, or improve myocardial relaxation. These additional properties influence the choice of drug for specific circumstances. Those used predominantly for their inotropic effects include cardiac glycosides and phosphodiesterase inhibitors.
Digoxin (Lanoxin)
Used to treat congestive heart failure. Cardiac glycoside with direct inotropic effects in addition to indirect effects on the cardiovascular system. Acts directly on cardiac muscle, increasing myocardial systolic contractions. Its indirect actions result in increased carotid sinus nerve activity and enhanced sympathetic withdrawal for any given increase in mean arterial pressure.
Dosing
Adult
0.125-0.375 mg PO qd
Pediatric
10 mcg/kg/d PO divided bid
Interactions
IV calcium may produce arrhythmias in digitalized patients
Medications that may increase digoxin levels include alprazolam, benzodiazepines, bepridil, captopril, cyclosporine, propafenone, propantheline, quinidine, diltiazem, aminoglycosides, PO amiodarone, anticholinergics, diphenoxylate, erythromycin, felodipine, flecainide, hydroxychloroquine, itraconazole, nifedipine, omeprazole, quinine, ibuprofen, indomethacin, esmolol, tetracycline, tolbutamide, and verapamil Medications that may decrease serum digoxin levels include aminoglutethimide, antihistamines, cholestyramine, neomycin, penicillamine, aminoglycosides, PO colestipol, hydantoins, hypoglycemic agents, antineoplastic treatment combinations (including carmustine, bleomycin, methotrexate, cytarabine, doxorubicin, cyclophosphamide, vincristine, and procarbazine), aluminum or magnesium antacids, rifampin, sucralfate, sulfasalazine, barbiturates, kaolin/pectin, and aminosalicylic acid
Contraindications
Documented hypersensitivity; beriberi heart disease; idiopathic hypertrophic subaortic stenosis; constrictive pericarditis; carotid sinus syndrome
Precautions
Pregnancy
C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus
Precautions
Hypokalemia may reduce positive inotropic effect of digitalis; hypercalcemia predisposes patient to digitalis toxicity, and hypocalcemia can make digoxin ineffective until serum calcium levels are within the reference range; magnesium replacement therapy must be instituted in patients with hypomagnesemia to prevent digitalis toxicity; patients diagnosed with incomplete AV block may progress to complete block when treated with digoxin; exercise caution in hypothyroidism, hypoxia, and acute myocarditis; adjust dose in renal impairment; highly toxic (overdoses can be fatal)
Angiotensin-converting enzyme (ACE) inhibitors
ACE inhibitors are beneficial in all stages of congestive heart failure. Pharmacologic effects result in a decrease in systemic vascular resistance, reducing blood pressure, preload, and afterload. Dyspnea and exercise tolerance are improved. Unlike diuretics, studies demonstrate improvement of survival and reduced progression of mild or moderate heart failure to more severe stages. Benefits asymptomatic left ventricular dysfunction.
Enalapril (Vasotec)
Used to treat congestive heart failure. Competitive inhibitor of ACE. Reduces angiotensin II levels, decreasing aldosterone secretion.
Dosing
Adult
2.5-5 mg/d PO (increase prn)
10-40 mg/d PO in 1-2 divided doses is dosing range
1.25 mg/dose IV infused over 5 min q6h
Pediatric
0.1 mg/kg/d PO initially; may gradually titrate upward; not to exceed 0.5 mg/kg/d PO divided bid
Interactions
NSAIDs may reduce hypotensive effects of enalapril; ACE inhibitors may increase digoxin, lithium, and allopurinol levels; rifampin decreases enalapril levels; probenecid may increase enalapril levels; the hypotensive effects of ACE inhibitors may be enhanced when administered concurrently with diuretics
Contraindications
Documented hypersensitivity
Precautions
Pregnancy
C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus
D - Fetal risk shown in humans; use only if benefits outweigh risk to fetus
Precautions
Category D in second and third trimester of pregnancy; caution in renal impairment, valvular stenosis, or severe CHF
Vaccines
Active immunization increases resistance to infection. Vaccines consist of microorganisms or cellular components, which act as antigens. Administration of the vaccine stimulates the production of antibodies with specific protective properties.
Pneumococcal vaccine (Pneumovax-23, Pnu-Imune 23)
Polyvalent vaccine used for prophylaxis against infection from Streptococcus pneumoniae. Used in populations at increased risk of pneumococcal pneumonia (ie, age >55 y, chronic infection, asplenia, immunocompromise).
Dosing
Adult
0.5 mL IM/SC once
Pediatric
<2 years: Contraindicated (antibody response is poor in this age group)
>2 years: 0.5 mL IM/SC; repeat dose after 3-5 y for high-risk children (eg, functional or anatomic asplenia, conditions associated with rapid antibody decline after initial vaccination)
Interactions
Immunosuppressive agents (eg, large amounts of corticosteroids, antimetabolites, alkylating agents, cytotoxic agents) may reduce effectiveness; therapy with immunoglobulin preparations is likely to block the active immunity induced with pneumococcal vaccination, withhold for 3 mo after discontinuation of immunoglobulin therapy
Contraindications
Documented hypersensitivity to any component or to thimerosal; severe or even a moderate febrile illness; age <2 y; thrombocytopenia or any coagulation disorder that would contraindicate IM injection unless potential benefit clearly outweighs risk of administration
Precautions
Pregnancy
C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus
Precautions
May cause relapse in patients with stable idiopathic thrombocytopenia purpura; adverse effects include arthralgia, fever, urticaria, and Guillain-Barré syndrome (rarely)
Antibiotics, prophylactic
Antibiotic prophylaxis is administered to patients before performing procedures that may cause bacteremia.
Amoxicillin (Amoxil, Trimox)
Interferes with synthesis of cell wall mucopeptides during active multiplication, resulting in bactericidal activity against susceptible bacteria. Used as prophylaxis in minor procedures.
Dosing
Adult
2 g PO 1 h before procedure
Alternatively, 3 g PO 1 h before procedure, followed by 1.5 g PO 6 h after initial dose
Pediatric
50 mg/kg PO 1 h before procedure; not to exceed 2 g/dose
Interactions
Reduces efficacy of PO contraceptives
Contraindications
Documented hypersensitivity
Precautions
Pregnancy
B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals
Precautions
Adjust dose in renal impairment
Ampicillin (Marcillin, Omnipen)
For prophylaxis in patients undergoing dental, PO, or respiratory tract procedures.
Coadministered with gentamicin for prophylaxis in GI or genitourinary procedures.
Dosing
Adult
2 g IV/IM 30 min before procedure
High-risk patients: 2 g ampicillin IV/IM plus gentamicin 1.5 mg/kg IV 30 min before procedure, followed 6 h later by 1 g ampicillin IV/IM or 1 g amoxicillin PO
Pediatric
50 mg/kg IV/IM 30 min before procedure; not to exceed 2 g/dose
High-risk patients: 50 mg/kg IV/IM ampicillin plus gentamicin 1.5 mg/kg IV 30 min before procedure, followed 6 h later by ampicillin 25 mg/kg IV/IM or amoxicillin 25 mg/kg PO
Interactions
Probenecid and disulfiram elevate levels; allopurinol decreases effects and has additive effects on ampicillin rash; may decrease effects of PO contraceptives
Contraindications
Documented hypersensitivity
Precautions
Pregnancy
B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals
Precautions
Adjust dose in renal failure; evaluate rash and differentiate from hypersensitivity reaction
Clindamycin (Cleocin)
Used in penicillin-allergic patients undergoing dental, PO, or respiratory tract procedures. Useful for treatment against streptococcal and most staphylococcal infections.
Dosing
Adult
600 mg PO/IV 1 h before procedure and 150 mg PO/IV 6 h after first dose
Pediatric
20 mg/kg PO 1 h or 20 mg/kg IV 30 min before procedure; not to exceed 600 mg/dose
Interactions
Increases duration of neuromuscular blockade induced by tubocurarine and pancuronium; erythromycin may antagonize effects; antidiarrheals may delay absorption
Contraindications
Documented hypersensitivity; regional enteritis; ulcerative colitis; hepatic impairment; antibiotic-associated colitis
Precautions
Pregnancy
B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals
Precautions
Adjust dose in severe hepatic dysfunction; no adjustment necessary in renal insufficiency; associated with severe and possibly fatal colitis
Gentamicin (Garamycin)
Aminoglycoside antibiotic for gram-negative coverage. Used in combination with an agent against gram-positive organisms and one that covers anaerobes.
Used in conjunction with ampicillin or vancomycin for prophylaxis in GI or genitourinary procedures.
Dosing
Adult
1.5 mg/kg IV; not to exceed 120 mg/dose; administer with ampicillin 2 g IV 30 min before procedure
Pediatric
1.5 mg/kg IV 30 min before procedure; not to exceed 120 mg/dose; administer with ampicillin 50 mg/kg IV; not to exceed 2 g/dose
Interactions
Coadministration with other aminoglycosides, cephalosporins, penicillins, and amphotericin B may increase nephrotoxicity; because aminoglycosides enhance effects of neuromuscular blocking agents, prolonged respiratory depression may occur; coadministration with loop diuretics may increase auditory toxicity of aminoglycosides; possible irreversible hearing loss of varying degrees may occur (monitor regularly)
Contraindications
Documented hypersensitivity; non–dialysis-dependent renal insufficiency
Precautions
Pregnancy
C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus
Precautions
Narrow therapeutic index (not intended for long-term therapy); caution in renal failure (patient not on dialysis), myasthenia gravis, hypocalcemia, and conditions that depress neuromuscular transmission; adjust dose in renal impairment
Vancomycin (Vancocin)
Potent antibiotic directed against gram-positive organisms and active against Enterococcus species. Useful in the treatment of septicemia and skin structure infections. Indicated for patients who cannot receive or have not responded to penicillins and cephalosporins or have infections with resistant staphylococci.
Use CrCl to adjust dose in renal impairment.
Used in conjunction with gentamicin for prophylaxis in penicillin-allergic patients undergoing GI or genitourinary procedures.
Dosing
Adult
Dental, PO, or upper respiratory tract surgery: 1 g IV infused over 1 h, 1 h before procedure
GI/GU procedures: 1 g IV plus gentamicin 1.5 mg/kg IV infused over 1 h, 1 h before surgery
Pediatric
Dental, PO, or upper respiratory tract surgery: 20 mg/kg IV infused over 1 h, 1 h before procedure
Interactions
Erythema, histaminelike flushing, and anaphylactic reactions may occur when administered with anesthetic agents; when taken concurrently with aminoglycosides, the risk of nephrotoxicity may increase above that with aminoglycoside monotherapy; effects in neuromuscular blockade may be enhanced when coadministered with nondepolarizing muscle relaxants
Contraindications
Documented hypersensitivity
Precautions
Pregnancy
C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus
Precautions
Caution in renal failure and neutropenia; red man syndrome is caused by too rapid IV infusion (dose administered over a few min) but rarely happens when dose is administered IV over 2 h or as PO/IP administration; red man syndrome is not an allergic reaction
Cefazolin (Ancef)
First-generation semisynthetic cephalosporin that arrests bacterial cell wall synthesis, inhibiting bacterial growth. Primarily active against skin flora, including Staphylococcus aureus.
Dosing
Adult
1 g IV/IM within 30 min before procedure
Pediatric
25 mg/kg IV/IM within 30 min before procedure; not to exceed 1 g/dose
Interactions
Probenecid prolongs effect; coadministration with aminoglycosides may increase renal toxicity; may yield false-positive urine-dip test results for glucose
Contraindications
Documented hypersensitivity
Precautions
Pregnancy
B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals
Precautions
Adjust dose in renal impairment; superinfections and promotion of nonsusceptible organisms may occur with prolonged use or repeated therapy
Cephalexin (Keflex)
First-generation cephalosporin that arrests bacterial growth by inhibiting bacterial cell wall synthesis. Bactericidal activity against rapidly growing organisms. Primary activity against skin flora and used for skin infections or prophylaxis in minor procedures.
Dosing
Adult
2 g PO 1 h before procedure
Pediatric
50 mg/kg PO 1 h before procedure; not to exceed 2 g/dose
Interactions
Coadministration with aminoglycosides increases nephrotoxic potential
Contraindications
Documented hypersensitivity
Precautions
Pregnancy
B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals
Precautions
Adjust dose in renal impairment
Cefadroxil (Duricef)
First-generation cephalosporin that arrests bacterial growth by inhibiting bacterial cell wall synthesis. Bactericidal activity against rapidly growing organisms. Primary activity against skin flora and used for skin infections or prophylaxis in minor procedures.
Dosing
Adult
2 g PO 1 h before procedure
Pediatric
50 mg/kg PO 1 h before procedure; not to exceed 2 g/dose
Interactions
Coadministration with furosemide or aminoglycosides may increase nephrotoxicity; probenecid prolongs effects
Contraindications
Documented hypersensitivity
Precautions
Pregnancy
B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals
Precautions
Adjust dose in renal impairment; superinfections and promotion of nonsusceptible organisms may occur with prolonged use or repeated therapy
Azithromycin (Zithromax)
Inhibits bacterial growth, possibly by blocking dissociation of peptidyl tRNA from ribosomes, causing RNA-dependent protein synthesis to arrest.
Dosing
Adult
500 mg PO 1 h before procedure
Pediatric
15 mg/kg PO 1 h before procedure; not to exceed 500 mg/dose
Interactions
May increase toxicity of theophylline, warfarin, and digoxin; effects are reduced with coadministration of aluminum and/or magnesium antacids; nephrotoxicity and neurotoxicity may occur when coadministered with cyclosporine
Contraindications
Documented hypersensitivity; hepatic impairment; administration with pimozide
Precautions
Pregnancy
B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals
Precautions
Bacterial or fungal overgrowth may result from prolonged antibiotic use; may increase hepatic enzymes and cholestatic jaundice; caution in patients with impaired hepatic function, prolonged QT intervals, or pneumonia; caution in patients who are hospitalized, geriatric, or debilitated
Clarithromycin (Biaxin)
Inhibits bacterial growth, possibly by blocking dissociation of peptidyl tRNA from ribosomes, causing RNA-dependent protein synthesis to arrest.
Dosing
Adult
500 mg PO 1 h before procedure
Pediatric
15 mg/kg PO 1 h before procedure; not to exceed 500 mg/dose
Interactions
Toxicity increases with coadministration of fluconazole, astemizole, and pimozide; effects decrease and GI adverse effects may increase with coadministration of rifabutin or rifampin; may increase toxicity of anticoagulants, cyclosporine, tacrolimus, digoxin, omeprazole, carbamazepine, ergot alkaloids, triazolam, and HMG CoA-reductase inhibitors; cardiac arrhythmias may occur with coadministration of cisapride; plasma levels of certain benzodiazepines may increase, prolonging CNS depression; arrhythmias and increases in QTc intervals occur with disopyramide; coadministration with omeprazole may increase plasma levels of both agents
Contraindications
Documented hypersensitivity; coadministration of pimozide
Precautions
Pregnancy
C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus
Precautions
Coadministration with ranitidine or bismuth citrate not recommended with CrCl <25 mL/min; administer half dose or increase dosing interval if CrCl <30 mL/min; diarrhea may be sign of pseudomembranous colitis; superinfections may occur with prolonged or repeated antibiotic therapies
Follow-up
Prognosis
- Without surgery, the mortality rate of asplenia is 95% in the first year of life. Palliative cardiac surgery improves the survival rate, particularly during infancy, but the 5-year mortality rate remains as high as 50%.
- Antibiotic prophylaxis may be needed in patients with splenic insufficiency.
Miscellaneous
Medicolegal Pitfalls
- Failure to consider GI malrotation in patients with cardiac and/or visceral heterotaxy: This may potentially result in delayed diagnosis of gut volvulus.
- Failure to consider splenic insufficiency in patients with heterotaxy: Liver-spleen scanning and RBC examination should be performed to identify spleen function.
Multimedia
Media file 1: Transverse ultrasonogram in a patient with asplenia. This image demonstrates the aorta and vena cava on either side of the midline, an appearance that simulates solitus anatomy.
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Keywords
asplenia, right atrial isomerism, laterality defects, cyanotic congenital heart disease, intestinal malrotation, anomalous pulmonary venous return, common atrium, endocardial cushion defects, double outlet right ventricle, treatment, diagnosis, biliary tract abnormalities, transverse liver, congestive heart failure, volvulus
Contributor Information and Disclosures
Author
Kevin M Shannon, MD, Associate Professor, Division of Pediatric Cardiology, Director of Pediatric Electrophysiology Program, UCLA School of Medicine; Consulting Staff, Pediatric Cardiology Clinic, Olive View-UCLA Medical Center
Kevin M Shannon, MD is a member of the following medical societies: American Academy of Pediatrics
Disclosure: Nothing to disclose.
Medical Editor
Charles I Berul, MD, Associate Professor of Pediatrics, Harvard Medical School; Senior Associate, Department of Cardiology, Children's Hospital of Boston
Charles I Berul, MD is a member of the following medical societies: American Academy of Pediatrics, American College of Cardiology, American Heart Association, Heart Rhythm Society, and Society for Pediatric Research
Disclosure: Nothing to disclose.
Pharmacy Editor
Mary L Windle, PharmD, Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy, Pharmacy Editor, eMedicine
Disclosure: Pfizer Inc Stock Investment from financial planner; Avanir Pharma Stock Investment from financial planner ; WebMD Salary and stock Employment and investment from financial planner
Managing Editor
Julian M Stewart, MD, PhD, Associate Chairman of Pediatrics, Director, Center for Hypotension, Westchester Medical Center; Professor of Pediatrics and Physiology, New York Medical College
Julian M Stewart, MD, PhD is a member of the following medical societies: American Academy of Pediatrics
Disclosure: Nothing to disclose.
CME Editor
Gilbert Z Herzberg, MD, Assistant Professor, Department of Pediatrics, Section of Pediatric Cardiology, New York Medical College; Consulting Staff, Department of Pediatrics, Sound Shore Medical Center
Gilbert Z Herzberg, MD is a member of the following medical societies: American Academy of Pediatrics
Disclosure: Nothing to disclose.
Chief Editor
Stuart Berger, MD, Professor of Pediatrics, Division of Cardiology, Medical College of Wisconsin; Chief of Pediatric Cardiology, Medical Director of Pediatric Heart Transplant Program, Medical Director of The Heart Center, Children's Hospital of Wisconsin
Stuart Berger, MD is a member of the following medical societies: American Academy of Pediatrics, American College of Cardiology, American College of Chest Physicians, American Heart Association, and Society for Cardiac Angiography and Interventions
Disclosure: Nothing to disclose.
Relevant clinical guidelines include the following:
- Infectious Diseases Society of America and American Thoracic Society consensus guidelines on the management of community-acquired pneumonia in adults
- American College of Radiology's appropriateness criteria for suspected congenital heart disease in the adult
Relevant clinical trials include the following:
- Efficacy and safety of clopidogrel in neonates and infants with systemic to pulmonary artery shunt palliation
- Iron prophylaxis for anemia in infants with cyanotic congenital heart disease
Related eMedicine topics include the following:
- Asplenia/Polysplenia
- Heterotaxy, Polysplenia
- Asplenia
- Atrial Septal Defect, Coronary Sinus
- Biliary Atresia
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