combination therapy is initiated with both BAL and CaNa2 EDTA; the BAL may be discontinued in many cases after to days, but CaNa2 EDTA is continued for days For symptomatic patients or those with high BLLs (>69 mcg/dL), CaNa2 EDTA should always be started hours after BAL due to the risk of worsening lead encephalopathy when CaNa2 EDTA is given alone in these patients Provide adequate hydration to promote urine output Symptomatic children without frank encephalopathy should receive chelation therapy with a combination of BAL for to days and CaNa2 EDTA for days Supportive care includes close monitoring for signs of encephalopathy and, again, maintenance of urine flow In the event of BAL or CaNa2 EDTA shortage, succimer may be an adequate substitute, although the evidence in support of its use for severe intoxication or encephalopathy is purely observational Patients with encephalopathy require combination chelation therapy with higher-dose CaNa2 EDTA and BAL for days, as well as intensive supportive care Fluid therapy is critical to achieve adequate urine flow to excrete the lead– chelate complexes; however, fluid overload can exacerbate cerebral edema Seizures commonly occur in acute encephalopathy and should be controlled with anticonvulsant drugs (see Chapter 72 Seizures ) Hypothetical concerns have been raised about the use of phenobarbital in lead encephalopathy (i.e., synergistic disturbances in porphyrin metabolism), but its clinical use has not been associated with any noticeable deleterious effect Recent advances have been made in the management of cerebral edema and increased intracranial pressure (see Chapter 122 Neurosurgical Emergencies ), but have not been evaluated in controlled fashion in the context of lead encephalopathy