Dispensary assistants were first chosen to be trained on the job to administer anaesthesia during the colonial era. This training short lived as it did not meet the required standard. CRAs were then chosen to replace the Dispensary assistants to continue with on-the-job training for a very short period to administer anaesthesia in Ghana.

However, during the Second World War, eleven (11) of these CRAs were recruited to join the army for the Second World War. Upon their return, their impressive performance gave them further opportunity to be given a formal six (6) months training at 37 Mmilitary Hospital.

They continued to administer anaesthesia together with other colleagues that were trained on the job in Nigeria.

In 1963, professor Oduro returned to Ghana as trained Doctor in anaesthesia and together they continued to provide anaesthesia services. This system of on-the-job training officially stopped in 1981.