Pass Redshift INOUT OUT parameter to AWS lambda invocation (boto3 client)

Is it possible to get a Redshift procedure inout (or out) parameter from a lambda invocation?

def lambda_handler(event, context):
    # This is my variable to get set by the Redshift proc
    out_param = "0"
    response = rs_client.execute_statement(
        ClusterIdentifier=cluster,
        Database=database,
        DbUser='my_user',
        Parameters=[
            {
                "name": "in_param1",
                "value": "this is a parameter"
            },
            {
                "name": "out_param1",
                "value": out_param
            }
        ],
        Sql="call my_schema.xxx_out_param(:in_param1, :out_param1)",
        StatementName='Test out parameter'
    )
    
    # Some code here checks that the statement has FINISHED status
    
    # The value printed out below is always zero and never the value that the proc sets the inout param to
    print(f"Value of OUT PARAM is: {out_param}")

The printed value of out_param is always 0 (zero) - its original value. The proc that I call simply assigns a hardcoded non-zero value. I have tested the proc in isolation to insert the value into a table and it works.

I cannot use a function for this. I am using existing code that derives an Id and need to obtain that Id that to trigger further processing. This is not ideal but I am working within existing system constraints.