The decision to send a patient home or to admit the patient should rely on the usual metrics: appearance on arrival, test results, response to therapy, parental comfort, and availability of follow-up Patients with high persistent fever, need for continuous intravenous hydration, or an evolving process should remain in hospital until their condition stabilizes Here again, transplant team input is essential to a successful outcome GRAFT REJECTION CLINICAL PEARLS AND PITFALLS Clinical signs and symptoms of rejection may be nonspecific and can mimic an infectious illness They include fever, abdominal pain, vomiting, tachypnea, malaise, and pallor Specific signs and symptoms of rejection for each solid organ transplant are listed in Table 125.2 If rejection is suspected based on clinical appearance, the transplant team must be notified immediately Do not wait for laboratory results In cardiac patients, when rejection is suspected and dehydration is present, consult with the transplant team prior to fluid resuscitation Early recognition and treatment of acute rejection results in improved outcomes TABLE 125.1 INTERACTIONS BETWEEN TRANSPLANT IMMUNOSUPPRESSANTS AND OTHER COMMONLY USED MEDICATIONS Current Evidence Cardiac Transplantation Acute cellular rejection (T cell mediated) most commonly occurs in the first months after heart transplant Twenty to forty percent of heart transplant recipients experience at least one episode of acute cellular rejection in the first postoperative year Acute antibody-mediated rejection is less common than cellular rejection, and occurs in about 10% of patients in conjunction with hemodynamic instability Most patients are asymptomatic during the early phases of rejection Surveillance, with serial echocardiography or right heart cardiac catheterization and endomyocardial biopsy, is required to identify early rejection and initiate treatment Clinical evidence of rejection signals a more advanced process, and may be identified by tachycardia and S3 gallop on examination Contributory symptoms may include malaise, pallor, fatigue, anorexia, nausea, or respiratory complaints More advanced rejections may be evidenced by hemodynamic instability, and on examination, hepatomegaly, pulmonary congestion, and JVD Liver Transplantation Acute cellular rejection occurs in up to two-thirds of patients following liver transplantation and is suspected when there is an increase in liver enzymes including bilirubin, GGT, and transaminases Rejection should also be suspected if immunosuppression levels are low Acute rejection is primarily diagnosed histologically because elevated LFTs can also be seen in other settings such as infection The histologic triad of bile duct injury, endothelialitis, and lymphocytic