Final answer:
The sole permanent record of events during an ambulance call is the Patient Care Report (PCR), essential for documenting medical care, patient condition, and actions by EMS personnel.
Step-by-step explanation:
The sole permanent, complete written record of events during the ambulance call is the PCR, which stands for Patient Care Report. This document is a comprehensive record that includes information about the medical care provided to the patient, the patient's condition, the actions taken by EMS personnel, and any changes in the patient's condition during transport. Ensuring accurate and thorough documentation in the PCR is crucial as it serves multiple purposes such as legal documentation, billing, and continuity of care.