DALLAS — A Dallas anesthesiologist was convicted Friday for injecting a nerve-blocking agent and other drugs into bags of intravenous fluid at a surgical center where he worked, which led to the death of a coworker and caused cardiac emergencies for several patients, federal prosecutors said.

A jury convicted Raynaldo Rivera Ortiz Jr., 60, of four counts of tampering with consumer products resulting in serious bodily injury, one count of tampering with a consumer product and five counts of…