Sending a notification from an RDS PostgreSQL instance (without pg_notify)?

Question

We have a Postgre RDS instance where new data is inserted every 5 seconds. We would like to set up some alerts based on the readings.

Theoretically, we should configure a trigger with the appropriate function to compare the value and send a notification, which will then be executed by LISTENed using a script, as described in this tutorial .

However, pg_notify is not available on Amazon RDS. Is there an alternative way to do this, besides scanning the table for updates every couple of seconds?

Thanks!