CREATE TABLE #Tables (tablename sysname, rowcnt int, nullable varchar)
GO

CREATE PROCEDURE #Proc
AS 
CREATE TABLE #t (a int NOT NULL )
INSERT #t SELECT 1 UNION SELECT 2 -- Insert two rows
-- Check which tables we inserted rows into
INSERT #Tables SELECT O.name, P.row_count, (SELECT is_nullable FROM sys.columns WHERE name = 'a' AND object_id = O.object_id) from sys.objects O, sys.dm_db_partition_stats P WHERE O.name LIKE '#t\_%' ESCAPE ('\') AND O.object_id = P.object_id
GO

GO
CREATE TABLE #t (a int NULL)
GO
INSERT #t SELECT 1 -- Insert one row
EXEC #Proc
GO

SELECT * FROM #Tables

DROP TABLE #t
DROP TABLE #Tables
DROP PROCEDURE #Proc
GO