use superuser connection from php

hello,

we have a php application which gets from time to time database errors 
which look like there are not enough connections (we have 100 
connections allowed to postgresql) -

i read that there are two db connections reserved for su. is there a way 
to use them from php in order to check if the database is really out of 
connections (with - 'SELECT count(*) FROM pg_stat_activity') or the 
problem is different?

thanks,
iv